зеркало из https://github.com/github/putty.git
9745 строки
285 KiB
C
9745 строки
285 KiB
C
/*
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* SSH backend.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <assert.h>
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#include <limits.h>
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#include <signal.h>
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#include "putty.h"
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#include "tree234.h"
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#include "ssh.h"
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#ifndef NO_GSSAPI
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#include "sshgss.h"
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#endif
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#ifndef FALSE
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#define FALSE 0
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#endif
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#ifndef TRUE
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#define TRUE 1
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#endif
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#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
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#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
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#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
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#define SSH1_CMSG_USER 4 /* 0x4 */
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#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
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#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
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#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
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#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
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#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
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#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
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#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
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#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
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#define SSH1_SMSG_SUCCESS 14 /* 0xe */
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#define SSH1_SMSG_FAILURE 15 /* 0xf */
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#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
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#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
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#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
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#define SSH1_CMSG_EOF 19 /* 0x13 */
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#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
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#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
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#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
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#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
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#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
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#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
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#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
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#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
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#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
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#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
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#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
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#define SSH1_MSG_IGNORE 32 /* 0x20 */
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#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
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#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
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#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
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#define SSH1_MSG_DEBUG 36 /* 0x24 */
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#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
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#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
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#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
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#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
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#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
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#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
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#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
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#define SSH1_AUTH_RHOSTS 1 /* 0x1 */
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#define SSH1_AUTH_RSA 2 /* 0x2 */
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#define SSH1_AUTH_PASSWORD 3 /* 0x3 */
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#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
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#define SSH1_AUTH_TIS 5 /* 0x5 */
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#define SSH1_AUTH_CCARD 16 /* 0x10 */
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#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
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/* Mask for protoflags we will echo back to server if seen */
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#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
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#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
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#define SSH2_MSG_IGNORE 2 /* 0x2 */
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#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
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#define SSH2_MSG_DEBUG 4 /* 0x4 */
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#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
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#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
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#define SSH2_MSG_KEXINIT 20 /* 0x14 */
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#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
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#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
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#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
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#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
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#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
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#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
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#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
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#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
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#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
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#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
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#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
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#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
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#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
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#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
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#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
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#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
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#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
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#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
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#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
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#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
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#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
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#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
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#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
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#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
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#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
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#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
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#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
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#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
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#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
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#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
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#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
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#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
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#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60
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#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61
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#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63
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#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64
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#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65
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#define SSH2_MSG_USERAUTH_GSSAPI_MIC 66
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/*
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* Packet type contexts, so that ssh2_pkt_type can correctly decode
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* the ambiguous type numbers back into the correct type strings.
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*/
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typedef enum {
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SSH2_PKTCTX_NOKEX,
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SSH2_PKTCTX_DHGROUP,
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SSH2_PKTCTX_DHGEX,
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SSH2_PKTCTX_RSAKEX
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} Pkt_KCtx;
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typedef enum {
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SSH2_PKTCTX_NOAUTH,
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SSH2_PKTCTX_PUBLICKEY,
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SSH2_PKTCTX_PASSWORD,
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SSH2_PKTCTX_GSSAPI,
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SSH2_PKTCTX_KBDINTER
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} Pkt_ACtx;
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#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
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#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
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#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
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#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
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#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
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#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
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#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
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#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
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#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
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#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
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#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
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#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
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#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
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#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
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#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
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static const char *const ssh2_disconnect_reasons[] = {
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NULL,
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"host not allowed to connect",
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"protocol error",
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"key exchange failed",
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"host authentication failed",
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"MAC error",
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"compression error",
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"service not available",
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"protocol version not supported",
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"host key not verifiable",
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"connection lost",
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"by application",
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"too many connections",
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"auth cancelled by user",
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"no more auth methods available",
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"illegal user name",
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};
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#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
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#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
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#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
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#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
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#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
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/*
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* Various remote-bug flags.
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*/
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#define BUG_CHOKES_ON_SSH1_IGNORE 1
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#define BUG_SSH2_HMAC 2
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#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
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#define BUG_CHOKES_ON_RSA 8
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#define BUG_SSH2_RSA_PADDING 16
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#define BUG_SSH2_DERIVEKEY 32
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#define BUG_SSH2_REKEY 64
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#define BUG_SSH2_PK_SESSIONID 128
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#define BUG_SSH2_MAXPKT 256
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/*
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* Codes for terminal modes.
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* Most of these are the same in SSH-1 and SSH-2.
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* This list is derived from RFC 4254 and
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* SSH-1 RFC-1.2.31.
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*/
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static const struct {
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const char* const mode;
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int opcode;
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enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
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} ssh_ttymodes[] = {
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/* "V" prefix discarded for special characters relative to SSH specs */
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{ "INTR", 1, TTY_OP_CHAR },
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{ "QUIT", 2, TTY_OP_CHAR },
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{ "ERASE", 3, TTY_OP_CHAR },
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{ "KILL", 4, TTY_OP_CHAR },
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{ "EOF", 5, TTY_OP_CHAR },
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{ "EOL", 6, TTY_OP_CHAR },
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{ "EOL2", 7, TTY_OP_CHAR },
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{ "START", 8, TTY_OP_CHAR },
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{ "STOP", 9, TTY_OP_CHAR },
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{ "SUSP", 10, TTY_OP_CHAR },
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{ "DSUSP", 11, TTY_OP_CHAR },
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{ "REPRINT", 12, TTY_OP_CHAR },
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{ "WERASE", 13, TTY_OP_CHAR },
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{ "LNEXT", 14, TTY_OP_CHAR },
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{ "FLUSH", 15, TTY_OP_CHAR },
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{ "SWTCH", 16, TTY_OP_CHAR },
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{ "STATUS", 17, TTY_OP_CHAR },
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{ "DISCARD", 18, TTY_OP_CHAR },
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{ "IGNPAR", 30, TTY_OP_BOOL },
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{ "PARMRK", 31, TTY_OP_BOOL },
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{ "INPCK", 32, TTY_OP_BOOL },
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{ "ISTRIP", 33, TTY_OP_BOOL },
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{ "INLCR", 34, TTY_OP_BOOL },
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{ "IGNCR", 35, TTY_OP_BOOL },
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{ "ICRNL", 36, TTY_OP_BOOL },
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{ "IUCLC", 37, TTY_OP_BOOL },
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{ "IXON", 38, TTY_OP_BOOL },
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{ "IXANY", 39, TTY_OP_BOOL },
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{ "IXOFF", 40, TTY_OP_BOOL },
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{ "IMAXBEL", 41, TTY_OP_BOOL },
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{ "ISIG", 50, TTY_OP_BOOL },
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{ "ICANON", 51, TTY_OP_BOOL },
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{ "XCASE", 52, TTY_OP_BOOL },
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{ "ECHO", 53, TTY_OP_BOOL },
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{ "ECHOE", 54, TTY_OP_BOOL },
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{ "ECHOK", 55, TTY_OP_BOOL },
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{ "ECHONL", 56, TTY_OP_BOOL },
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{ "NOFLSH", 57, TTY_OP_BOOL },
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{ "TOSTOP", 58, TTY_OP_BOOL },
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{ "IEXTEN", 59, TTY_OP_BOOL },
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{ "ECHOCTL", 60, TTY_OP_BOOL },
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{ "ECHOKE", 61, TTY_OP_BOOL },
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{ "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
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{ "OPOST", 70, TTY_OP_BOOL },
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{ "OLCUC", 71, TTY_OP_BOOL },
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{ "ONLCR", 72, TTY_OP_BOOL },
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{ "OCRNL", 73, TTY_OP_BOOL },
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{ "ONOCR", 74, TTY_OP_BOOL },
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{ "ONLRET", 75, TTY_OP_BOOL },
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{ "CS7", 90, TTY_OP_BOOL },
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{ "CS8", 91, TTY_OP_BOOL },
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{ "PARENB", 92, TTY_OP_BOOL },
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{ "PARODD", 93, TTY_OP_BOOL }
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};
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/* Miscellaneous other tty-related constants. */
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#define SSH_TTY_OP_END 0
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/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
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#define SSH1_TTY_OP_ISPEED 192
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#define SSH1_TTY_OP_OSPEED 193
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#define SSH2_TTY_OP_ISPEED 128
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#define SSH2_TTY_OP_OSPEED 129
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/* Helper functions for parsing tty-related config. */
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static unsigned int ssh_tty_parse_specchar(char *s)
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{
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unsigned int ret;
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if (*s) {
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char *next = NULL;
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ret = ctrlparse(s, &next);
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if (!next) ret = s[0];
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} else {
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ret = 255; /* special value meaning "don't set" */
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}
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return ret;
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}
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static unsigned int ssh_tty_parse_boolean(char *s)
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{
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if (stricmp(s, "yes") == 0 ||
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stricmp(s, "on") == 0 ||
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stricmp(s, "true") == 0 ||
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stricmp(s, "+") == 0)
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return 1; /* true */
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else if (stricmp(s, "no") == 0 ||
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stricmp(s, "off") == 0 ||
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stricmp(s, "false") == 0 ||
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stricmp(s, "-") == 0)
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return 0; /* false */
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else
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return (atoi(s) != 0);
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}
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#define translate(x) if (type == x) return #x
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#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
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#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
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static char *ssh1_pkt_type(int type)
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{
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translate(SSH1_MSG_DISCONNECT);
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translate(SSH1_SMSG_PUBLIC_KEY);
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translate(SSH1_CMSG_SESSION_KEY);
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translate(SSH1_CMSG_USER);
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translate(SSH1_CMSG_AUTH_RSA);
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translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
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translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
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translate(SSH1_CMSG_AUTH_PASSWORD);
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translate(SSH1_CMSG_REQUEST_PTY);
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translate(SSH1_CMSG_WINDOW_SIZE);
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translate(SSH1_CMSG_EXEC_SHELL);
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translate(SSH1_CMSG_EXEC_CMD);
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translate(SSH1_SMSG_SUCCESS);
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translate(SSH1_SMSG_FAILURE);
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translate(SSH1_CMSG_STDIN_DATA);
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translate(SSH1_SMSG_STDOUT_DATA);
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translate(SSH1_SMSG_STDERR_DATA);
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translate(SSH1_CMSG_EOF);
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translate(SSH1_SMSG_EXIT_STATUS);
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translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
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translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
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translate(SSH1_MSG_CHANNEL_DATA);
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translate(SSH1_MSG_CHANNEL_CLOSE);
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translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
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translate(SSH1_SMSG_X11_OPEN);
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translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
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translate(SSH1_MSG_PORT_OPEN);
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translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
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translate(SSH1_SMSG_AGENT_OPEN);
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translate(SSH1_MSG_IGNORE);
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translate(SSH1_CMSG_EXIT_CONFIRMATION);
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translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
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translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
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translate(SSH1_MSG_DEBUG);
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translate(SSH1_CMSG_REQUEST_COMPRESSION);
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translate(SSH1_CMSG_AUTH_TIS);
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translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
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translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
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translate(SSH1_CMSG_AUTH_CCARD);
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translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
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translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
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return "unknown";
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}
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static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
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{
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translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
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translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
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translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
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translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
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translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
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translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
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translate(SSH2_MSG_DISCONNECT);
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translate(SSH2_MSG_IGNORE);
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translate(SSH2_MSG_UNIMPLEMENTED);
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translate(SSH2_MSG_DEBUG);
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translate(SSH2_MSG_SERVICE_REQUEST);
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translate(SSH2_MSG_SERVICE_ACCEPT);
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translate(SSH2_MSG_KEXINIT);
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translate(SSH2_MSG_NEWKEYS);
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translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
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translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
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translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
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translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
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translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
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translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
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translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
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translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
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translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
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translate(SSH2_MSG_USERAUTH_REQUEST);
|
|
translate(SSH2_MSG_USERAUTH_FAILURE);
|
|
translate(SSH2_MSG_USERAUTH_SUCCESS);
|
|
translate(SSH2_MSG_USERAUTH_BANNER);
|
|
translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
|
|
translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
|
|
translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
|
|
translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
|
|
translate(SSH2_MSG_GLOBAL_REQUEST);
|
|
translate(SSH2_MSG_REQUEST_SUCCESS);
|
|
translate(SSH2_MSG_REQUEST_FAILURE);
|
|
translate(SSH2_MSG_CHANNEL_OPEN);
|
|
translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
|
|
translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
|
|
translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
translate(SSH2_MSG_CHANNEL_DATA);
|
|
translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
|
|
translate(SSH2_MSG_CHANNEL_EOF);
|
|
translate(SSH2_MSG_CHANNEL_CLOSE);
|
|
translate(SSH2_MSG_CHANNEL_REQUEST);
|
|
translate(SSH2_MSG_CHANNEL_SUCCESS);
|
|
translate(SSH2_MSG_CHANNEL_FAILURE);
|
|
return "unknown";
|
|
}
|
|
#undef translate
|
|
#undef translatec
|
|
|
|
/* Enumeration values for fields in SSH-1 packets */
|
|
enum {
|
|
PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
|
|
/* These values are for communicating relevant semantics of
|
|
* fields to the packet logging code. */
|
|
PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
|
|
};
|
|
|
|
/*
|
|
* Coroutine mechanics for the sillier bits of the code. If these
|
|
* macros look impenetrable to you, you might find it helpful to
|
|
* read
|
|
*
|
|
* http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
|
|
*
|
|
* which explains the theory behind these macros.
|
|
*
|
|
* In particular, if you are getting `case expression not constant'
|
|
* errors when building with MS Visual Studio, this is because MS's
|
|
* Edit and Continue debugging feature causes their compiler to
|
|
* violate ANSI C. To disable Edit and Continue debugging:
|
|
*
|
|
* - right-click ssh.c in the FileView
|
|
* - click Settings
|
|
* - select the C/C++ tab and the General category
|
|
* - under `Debug info:', select anything _other_ than `Program
|
|
* Database for Edit and Continue'.
|
|
*/
|
|
#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
|
|
#define crState(t) \
|
|
struct t *s; \
|
|
if (!ssh->t) ssh->t = snew(struct t); \
|
|
s = ssh->t;
|
|
#define crFinish(z) } *crLine = 0; return (z); }
|
|
#define crFinishV } *crLine = 0; return; }
|
|
#define crReturn(z) \
|
|
do {\
|
|
*crLine =__LINE__; return (z); case __LINE__:;\
|
|
} while (0)
|
|
#define crReturnV \
|
|
do {\
|
|
*crLine=__LINE__; return; case __LINE__:;\
|
|
} while (0)
|
|
#define crStop(z) do{ *crLine = 0; return (z); }while(0)
|
|
#define crStopV do{ *crLine = 0; return; }while(0)
|
|
#define crWaitUntil(c) do { crReturn(0); } while (!(c))
|
|
#define crWaitUntilV(c) do { crReturnV; } while (!(c))
|
|
|
|
typedef struct ssh_tag *Ssh;
|
|
struct Packet;
|
|
|
|
static struct Packet *ssh1_pkt_init(int pkt_type);
|
|
static struct Packet *ssh2_pkt_init(int pkt_type);
|
|
static void ssh_pkt_ensure(struct Packet *, int length);
|
|
static void ssh_pkt_adddata(struct Packet *, void *data, int len);
|
|
static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
|
|
static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
|
|
static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
|
|
static void ssh_pkt_addstring_start(struct Packet *);
|
|
static void ssh_pkt_addstring_str(struct Packet *, char *data);
|
|
static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
|
|
static void ssh_pkt_addstring(struct Packet *, char *data);
|
|
static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
|
|
static void ssh1_pkt_addmp(struct Packet *, Bignum b);
|
|
static void ssh2_pkt_addmp(struct Packet *, Bignum b);
|
|
static int ssh2_pkt_construct(Ssh, struct Packet *);
|
|
static void ssh2_pkt_send(Ssh, struct Packet *);
|
|
static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
|
|
static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
|
|
struct Packet *pktin);
|
|
static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
|
|
struct Packet *pktin);
|
|
|
|
/*
|
|
* Buffer management constants. There are several of these for
|
|
* various different purposes:
|
|
*
|
|
* - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
|
|
* on a local data stream before we throttle the whole SSH
|
|
* connection (in SSH-1 only). Throttling the whole connection is
|
|
* pretty drastic so we set this high in the hope it won't
|
|
* happen very often.
|
|
*
|
|
* - SSH_MAX_BACKLOG is the amount of backlog that must build up
|
|
* on the SSH connection itself before we defensively throttle
|
|
* _all_ local data streams. This is pretty drastic too (though
|
|
* thankfully unlikely in SSH-2 since the window mechanism should
|
|
* ensure that the server never has any need to throttle its end
|
|
* of the connection), so we set this high as well.
|
|
*
|
|
* - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
|
|
* channels.
|
|
*
|
|
* - OUR_V2_BIGWIN is the window size we advertise for the only
|
|
* channel in a simple connection. It must be <= INT_MAX.
|
|
*
|
|
* - OUR_V2_MAXPKT is the official "maximum packet size" we send
|
|
* to the remote side. This actually has nothing to do with the
|
|
* size of the _packet_, but is instead a limit on the amount
|
|
* of data we're willing to receive in a single SSH2 channel
|
|
* data message.
|
|
*
|
|
* - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
|
|
* _packet_ we're prepared to cope with. It must be a multiple
|
|
* of the cipher block size, and must be at least 35000.
|
|
*/
|
|
|
|
#define SSH1_BUFFER_LIMIT 32768
|
|
#define SSH_MAX_BACKLOG 32768
|
|
#define OUR_V2_WINSIZE 16384
|
|
#define OUR_V2_BIGWIN 0x7fffffff
|
|
#define OUR_V2_MAXPKT 0x4000UL
|
|
#define OUR_V2_PACKETLIMIT 0x9000UL
|
|
|
|
/* Maximum length of passwords/passphrases (arbitrary) */
|
|
#define SSH_MAX_PASSWORD_LEN 100
|
|
|
|
const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
|
|
|
|
const static struct ssh_mac *macs[] = {
|
|
&ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
|
|
};
|
|
const static struct ssh_mac *buggymacs[] = {
|
|
&ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
|
|
};
|
|
|
|
static void *ssh_comp_none_init(void)
|
|
{
|
|
return NULL;
|
|
}
|
|
static void ssh_comp_none_cleanup(void *handle)
|
|
{
|
|
}
|
|
static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
|
|
unsigned char **outblock, int *outlen)
|
|
{
|
|
return 0;
|
|
}
|
|
static int ssh_comp_none_disable(void *handle)
|
|
{
|
|
return 0;
|
|
}
|
|
const static struct ssh_compress ssh_comp_none = {
|
|
"none",
|
|
ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
|
|
ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
|
|
ssh_comp_none_disable, NULL
|
|
};
|
|
extern const struct ssh_compress ssh_zlib;
|
|
const static struct ssh_compress *compressions[] = {
|
|
&ssh_zlib, &ssh_comp_none
|
|
};
|
|
|
|
enum { /* channel types */
|
|
CHAN_MAINSESSION,
|
|
CHAN_X11,
|
|
CHAN_AGENT,
|
|
CHAN_SOCKDATA,
|
|
CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
|
|
};
|
|
|
|
/*
|
|
* little structure to keep track of outstanding WINDOW_ADJUSTs
|
|
*/
|
|
struct winadj {
|
|
struct winadj *next;
|
|
unsigned size;
|
|
};
|
|
|
|
/*
|
|
* 2-3-4 tree storing channels.
|
|
*/
|
|
struct ssh_channel {
|
|
Ssh ssh; /* pointer back to main context */
|
|
unsigned remoteid, localid;
|
|
int type;
|
|
/* True if we opened this channel but server hasn't confirmed. */
|
|
int halfopen;
|
|
/*
|
|
* In SSH-1, this value contains four bits:
|
|
*
|
|
* 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
|
|
* 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
|
|
* 4 We have received SSH1_MSG_CHANNEL_CLOSE.
|
|
* 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
|
|
*
|
|
* A channel is completely finished with when all four bits are set.
|
|
*/
|
|
int closes;
|
|
/*
|
|
* True if this channel is causing the underlying connection to be
|
|
* throttled.
|
|
*/
|
|
int throttling_conn;
|
|
union {
|
|
struct ssh2_data_channel {
|
|
bufchain outbuffer;
|
|
unsigned remwindow, remmaxpkt;
|
|
/* locwindow is signed so we can cope with excess data. */
|
|
int locwindow, locmaxwin;
|
|
/*
|
|
* remlocwin is the amount of local window that we think
|
|
* the remote end had available to it after it sent the
|
|
* last data packet or window adjust ack.
|
|
*/
|
|
int remlocwin;
|
|
/*
|
|
* These store the list of window adjusts that haven't
|
|
* been acked.
|
|
*/
|
|
struct winadj *winadj_head, *winadj_tail;
|
|
enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
|
|
} v2;
|
|
} v;
|
|
union {
|
|
struct ssh_agent_channel {
|
|
unsigned char *message;
|
|
unsigned char msglen[4];
|
|
unsigned lensofar, totallen;
|
|
} a;
|
|
struct ssh_x11_channel {
|
|
Socket s;
|
|
} x11;
|
|
struct ssh_pfd_channel {
|
|
Socket s;
|
|
} pfd;
|
|
} u;
|
|
};
|
|
|
|
/*
|
|
* 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
|
|
* use this structure in different ways, reflecting SSH-2's
|
|
* altogether saner approach to port forwarding.
|
|
*
|
|
* In SSH-1, you arrange a remote forwarding by sending the server
|
|
* the remote port number, and the local destination host:port.
|
|
* When a connection comes in, the server sends you back that
|
|
* host:port pair, and you connect to it. This is a ready-made
|
|
* security hole if you're not on the ball: a malicious server
|
|
* could send you back _any_ host:port pair, so if you trustingly
|
|
* connect to the address it gives you then you've just opened the
|
|
* entire inside of your corporate network just by connecting
|
|
* through it to a dodgy SSH server. Hence, we must store a list of
|
|
* host:port pairs we _are_ trying to forward to, and reject a
|
|
* connection request from the server if it's not in the list.
|
|
*
|
|
* In SSH-2, each side of the connection minds its own business and
|
|
* doesn't send unnecessary information to the other. You arrange a
|
|
* remote forwarding by sending the server just the remote port
|
|
* number. When a connection comes in, the server tells you which
|
|
* of its ports was connected to; and _you_ have to remember what
|
|
* local host:port pair went with that port number.
|
|
*
|
|
* Hence, in SSH-1 this structure is indexed by destination
|
|
* host:port pair, whereas in SSH-2 it is indexed by source port.
|
|
*/
|
|
struct ssh_portfwd; /* forward declaration */
|
|
|
|
struct ssh_rportfwd {
|
|
unsigned sport, dport;
|
|
char dhost[256];
|
|
char *sportdesc;
|
|
struct ssh_portfwd *pfrec;
|
|
};
|
|
#define free_rportfwd(pf) ( \
|
|
((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
|
|
|
|
/*
|
|
* Separately to the rportfwd tree (which is for looking up port
|
|
* open requests from the server), a tree of _these_ structures is
|
|
* used to keep track of all the currently open port forwardings,
|
|
* so that we can reconfigure in mid-session if the user requests
|
|
* it.
|
|
*/
|
|
struct ssh_portfwd {
|
|
enum { DESTROY, KEEP, CREATE } status;
|
|
int type;
|
|
unsigned sport, dport;
|
|
char *saddr, *daddr;
|
|
char *sserv, *dserv;
|
|
struct ssh_rportfwd *remote;
|
|
int addressfamily;
|
|
void *local;
|
|
};
|
|
#define free_portfwd(pf) ( \
|
|
((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
|
|
sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
|
|
|
|
struct Packet {
|
|
long length; /* length of `data' actually used */
|
|
long forcepad; /* SSH-2: force padding to at least this length */
|
|
int type; /* only used for incoming packets */
|
|
unsigned long sequence; /* SSH-2 incoming sequence number */
|
|
unsigned char *data; /* allocated storage */
|
|
unsigned char *body; /* offset of payload within `data' */
|
|
long savedpos; /* temporary index into `data' (for strings) */
|
|
long maxlen; /* amount of storage allocated for `data' */
|
|
long encrypted_len; /* for SSH-2 total-size counting */
|
|
|
|
/*
|
|
* State associated with packet logging
|
|
*/
|
|
int logmode;
|
|
int nblanks;
|
|
struct logblank_t *blanks;
|
|
};
|
|
|
|
static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pktin);
|
|
static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pktin);
|
|
static void ssh1_protocol_setup(Ssh ssh);
|
|
static void ssh2_protocol_setup(Ssh ssh);
|
|
static void ssh_size(void *handle, int width, int height);
|
|
static void ssh_special(void *handle, Telnet_Special);
|
|
static int ssh2_try_send(struct ssh_channel *c);
|
|
static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
|
|
static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
|
|
static void ssh2_set_window(struct ssh_channel *c, int newwin);
|
|
static int ssh_sendbuffer(void *handle);
|
|
static int ssh_do_close(Ssh ssh, int notify_exit);
|
|
static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
|
|
static int ssh2_pkt_getbool(struct Packet *pkt);
|
|
static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
|
|
static void ssh2_timer(void *ctx, long now);
|
|
static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pktin);
|
|
|
|
struct rdpkt1_state_tag {
|
|
long len, pad, biglen, to_read;
|
|
unsigned long realcrc, gotcrc;
|
|
unsigned char *p;
|
|
int i;
|
|
int chunk;
|
|
struct Packet *pktin;
|
|
};
|
|
|
|
struct rdpkt2_state_tag {
|
|
long len, pad, payload, packetlen, maclen;
|
|
int i;
|
|
int cipherblk;
|
|
unsigned long incoming_sequence;
|
|
struct Packet *pktin;
|
|
};
|
|
|
|
typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
|
|
typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
|
|
|
|
struct queued_handler;
|
|
struct queued_handler {
|
|
int msg1, msg2;
|
|
chandler_fn_t handler;
|
|
void *ctx;
|
|
struct queued_handler *next;
|
|
};
|
|
|
|
struct ssh_tag {
|
|
const struct plug_function_table *fn;
|
|
/* the above field _must_ be first in the structure */
|
|
|
|
char *v_c, *v_s;
|
|
void *exhash;
|
|
|
|
Socket s;
|
|
|
|
void *ldisc;
|
|
void *logctx;
|
|
|
|
unsigned char session_key[32];
|
|
int v1_compressing;
|
|
int v1_remote_protoflags;
|
|
int v1_local_protoflags;
|
|
int agentfwd_enabled;
|
|
int X11_fwd_enabled;
|
|
int remote_bugs;
|
|
const struct ssh_cipher *cipher;
|
|
void *v1_cipher_ctx;
|
|
void *crcda_ctx;
|
|
const struct ssh2_cipher *cscipher, *sccipher;
|
|
void *cs_cipher_ctx, *sc_cipher_ctx;
|
|
const struct ssh_mac *csmac, *scmac;
|
|
void *cs_mac_ctx, *sc_mac_ctx;
|
|
const struct ssh_compress *cscomp, *sccomp;
|
|
void *cs_comp_ctx, *sc_comp_ctx;
|
|
const struct ssh_kex *kex;
|
|
const struct ssh_signkey *hostkey;
|
|
unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
|
|
int v2_session_id_len;
|
|
void *kex_ctx;
|
|
|
|
char *savedhost;
|
|
int savedport;
|
|
int send_ok;
|
|
int echoing, editing;
|
|
|
|
void *frontend;
|
|
|
|
int ospeed, ispeed; /* temporaries */
|
|
int term_width, term_height;
|
|
|
|
tree234 *channels; /* indexed by local id */
|
|
struct ssh_channel *mainchan; /* primary session channel */
|
|
int ncmode; /* is primary channel direct-tcpip? */
|
|
int exitcode;
|
|
int close_expected;
|
|
int clean_exit;
|
|
|
|
tree234 *rportfwds, *portfwds;
|
|
|
|
enum {
|
|
SSH_STATE_PREPACKET,
|
|
SSH_STATE_BEFORE_SIZE,
|
|
SSH_STATE_INTERMED,
|
|
SSH_STATE_SESSION,
|
|
SSH_STATE_CLOSED
|
|
} state;
|
|
|
|
int size_needed, eof_needed;
|
|
|
|
struct Packet **queue;
|
|
int queuelen, queuesize;
|
|
int queueing;
|
|
unsigned char *deferred_send_data;
|
|
int deferred_len, deferred_size;
|
|
|
|
/*
|
|
* Gross hack: pscp will try to start SFTP but fall back to
|
|
* scp1 if that fails. This variable is the means by which
|
|
* scp.c can reach into the SSH code and find out which one it
|
|
* got.
|
|
*/
|
|
int fallback_cmd;
|
|
|
|
bufchain banner; /* accumulates banners during do_ssh2_authconn */
|
|
|
|
Pkt_KCtx pkt_kctx;
|
|
Pkt_ACtx pkt_actx;
|
|
|
|
struct X11Display *x11disp;
|
|
|
|
int version;
|
|
int conn_throttle_count;
|
|
int overall_bufsize;
|
|
int throttled_all;
|
|
int v1_stdout_throttling;
|
|
unsigned long v2_outgoing_sequence;
|
|
|
|
int ssh1_rdpkt_crstate;
|
|
int ssh2_rdpkt_crstate;
|
|
int do_ssh_init_crstate;
|
|
int ssh_gotdata_crstate;
|
|
int do_ssh1_login_crstate;
|
|
int do_ssh1_connection_crstate;
|
|
int do_ssh2_transport_crstate;
|
|
int do_ssh2_authconn_crstate;
|
|
|
|
void *do_ssh_init_state;
|
|
void *do_ssh1_login_state;
|
|
void *do_ssh2_transport_state;
|
|
void *do_ssh2_authconn_state;
|
|
|
|
struct rdpkt1_state_tag rdpkt1_state;
|
|
struct rdpkt2_state_tag rdpkt2_state;
|
|
|
|
/* SSH-1 and SSH-2 use this for different things, but both use it */
|
|
int protocol_initial_phase_done;
|
|
|
|
void (*protocol) (Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pkt);
|
|
struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
|
|
|
|
/*
|
|
* We maintain a full _copy_ of a Config structure here, not
|
|
* merely a pointer to it. That way, when we're passed a new
|
|
* one for reconfiguration, we can check the differences and
|
|
* potentially reconfigure port forwardings etc in mid-session.
|
|
*/
|
|
Config cfg;
|
|
|
|
/*
|
|
* Used to transfer data back from async callbacks.
|
|
*/
|
|
void *agent_response;
|
|
int agent_response_len;
|
|
int user_response;
|
|
|
|
/*
|
|
* The SSH connection can be set as `frozen', meaning we are
|
|
* not currently accepting incoming data from the network. This
|
|
* is slightly more serious than setting the _socket_ as
|
|
* frozen, because we may already have had data passed to us
|
|
* from the network which we need to delay processing until
|
|
* after the freeze is lifted, so we also need a bufchain to
|
|
* store that data.
|
|
*/
|
|
int frozen;
|
|
bufchain queued_incoming_data;
|
|
|
|
/*
|
|
* Dispatch table for packet types that we may have to deal
|
|
* with at any time.
|
|
*/
|
|
handler_fn_t packet_dispatch[256];
|
|
|
|
/*
|
|
* Queues of one-off handler functions for success/failure
|
|
* indications from a request.
|
|
*/
|
|
struct queued_handler *qhead, *qtail;
|
|
|
|
/*
|
|
* This module deals with sending keepalives.
|
|
*/
|
|
Pinger pinger;
|
|
|
|
/*
|
|
* Track incoming and outgoing data sizes and time, for
|
|
* size-based rekeys.
|
|
*/
|
|
unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
|
|
unsigned long max_data_size;
|
|
int kex_in_progress;
|
|
long next_rekey, last_rekey;
|
|
char *deferred_rekey_reason; /* points to STATIC string; don't free */
|
|
|
|
/*
|
|
* Fully qualified host name, which we need if doing GSSAPI.
|
|
*/
|
|
char *fullhostname;
|
|
};
|
|
|
|
#define logevent(s) logevent(ssh->frontend, s)
|
|
|
|
/* logevent, only printf-formatted. */
|
|
static void logeventf(Ssh ssh, const char *fmt, ...)
|
|
{
|
|
va_list ap;
|
|
char *buf;
|
|
|
|
va_start(ap, fmt);
|
|
buf = dupvprintf(fmt, ap);
|
|
va_end(ap);
|
|
logevent(buf);
|
|
sfree(buf);
|
|
}
|
|
|
|
#define bombout(msg) \
|
|
do { \
|
|
char *text = dupprintf msg; \
|
|
ssh_do_close(ssh, FALSE); \
|
|
logevent(text); \
|
|
connection_fatal(ssh->frontend, "%s", text); \
|
|
sfree(text); \
|
|
} while (0)
|
|
|
|
/* Functions to leave bits out of the SSH packet log file. */
|
|
|
|
static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
|
|
{
|
|
if (ssh->cfg.logomitpass)
|
|
pkt->logmode = blanktype;
|
|
}
|
|
|
|
static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
|
|
{
|
|
if (ssh->cfg.logomitdata)
|
|
pkt->logmode = blanktype;
|
|
}
|
|
|
|
static void end_log_omission(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
pkt->logmode = PKTLOG_EMIT;
|
|
}
|
|
|
|
/* Helper function for common bits of parsing cfg.ttymodes. */
|
|
static void parse_ttymodes(Ssh ssh, char *modes,
|
|
void (*do_mode)(void *data, char *mode, char *val),
|
|
void *data)
|
|
{
|
|
while (*modes) {
|
|
char *t = strchr(modes, '\t');
|
|
char *m = snewn(t-modes+1, char);
|
|
char *val;
|
|
strncpy(m, modes, t-modes);
|
|
m[t-modes] = '\0';
|
|
if (*(t+1) == 'A')
|
|
val = get_ttymode(ssh->frontend, m);
|
|
else
|
|
val = dupstr(t+2);
|
|
if (val)
|
|
do_mode(data, m, val);
|
|
sfree(m);
|
|
sfree(val);
|
|
modes += strlen(modes) + 1;
|
|
}
|
|
}
|
|
|
|
static int ssh_channelcmp(void *av, void *bv)
|
|
{
|
|
struct ssh_channel *a = (struct ssh_channel *) av;
|
|
struct ssh_channel *b = (struct ssh_channel *) bv;
|
|
if (a->localid < b->localid)
|
|
return -1;
|
|
if (a->localid > b->localid)
|
|
return +1;
|
|
return 0;
|
|
}
|
|
static int ssh_channelfind(void *av, void *bv)
|
|
{
|
|
unsigned *a = (unsigned *) av;
|
|
struct ssh_channel *b = (struct ssh_channel *) bv;
|
|
if (*a < b->localid)
|
|
return -1;
|
|
if (*a > b->localid)
|
|
return +1;
|
|
return 0;
|
|
}
|
|
|
|
static int ssh_rportcmp_ssh1(void *av, void *bv)
|
|
{
|
|
struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
|
|
struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
|
|
int i;
|
|
if ( (i = strcmp(a->dhost, b->dhost)) != 0)
|
|
return i < 0 ? -1 : +1;
|
|
if (a->dport > b->dport)
|
|
return +1;
|
|
if (a->dport < b->dport)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
static int ssh_rportcmp_ssh2(void *av, void *bv)
|
|
{
|
|
struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
|
|
struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
|
|
|
|
if (a->sport > b->sport)
|
|
return +1;
|
|
if (a->sport < b->sport)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Special form of strcmp which can cope with NULL inputs. NULL is
|
|
* defined to sort before even the empty string.
|
|
*/
|
|
static int nullstrcmp(const char *a, const char *b)
|
|
{
|
|
if (a == NULL && b == NULL)
|
|
return 0;
|
|
if (a == NULL)
|
|
return -1;
|
|
if (b == NULL)
|
|
return +1;
|
|
return strcmp(a, b);
|
|
}
|
|
|
|
static int ssh_portcmp(void *av, void *bv)
|
|
{
|
|
struct ssh_portfwd *a = (struct ssh_portfwd *) av;
|
|
struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
|
|
int i;
|
|
if (a->type > b->type)
|
|
return +1;
|
|
if (a->type < b->type)
|
|
return -1;
|
|
if (a->addressfamily > b->addressfamily)
|
|
return +1;
|
|
if (a->addressfamily < b->addressfamily)
|
|
return -1;
|
|
if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
|
|
return i < 0 ? -1 : +1;
|
|
if (a->sport > b->sport)
|
|
return +1;
|
|
if (a->sport < b->sport)
|
|
return -1;
|
|
if (a->type != 'D') {
|
|
if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
|
|
return i < 0 ? -1 : +1;
|
|
if (a->dport > b->dport)
|
|
return +1;
|
|
if (a->dport < b->dport)
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int alloc_channel_id(Ssh ssh)
|
|
{
|
|
const unsigned CHANNEL_NUMBER_OFFSET = 256;
|
|
unsigned low, high, mid;
|
|
int tsize;
|
|
struct ssh_channel *c;
|
|
|
|
/*
|
|
* First-fit allocation of channel numbers: always pick the
|
|
* lowest unused one. To do this, binary-search using the
|
|
* counted B-tree to find the largest channel ID which is in a
|
|
* contiguous sequence from the beginning. (Precisely
|
|
* everything in that sequence must have ID equal to its tree
|
|
* index plus CHANNEL_NUMBER_OFFSET.)
|
|
*/
|
|
tsize = count234(ssh->channels);
|
|
|
|
low = -1;
|
|
high = tsize;
|
|
while (high - low > 1) {
|
|
mid = (high + low) / 2;
|
|
c = index234(ssh->channels, mid);
|
|
if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
|
|
low = mid; /* this one is fine */
|
|
else
|
|
high = mid; /* this one is past it */
|
|
}
|
|
/*
|
|
* Now low points to either -1, or the tree index of the
|
|
* largest ID in the initial sequence.
|
|
*/
|
|
{
|
|
unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
|
|
assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
|
|
}
|
|
return low + 1 + CHANNEL_NUMBER_OFFSET;
|
|
}
|
|
|
|
static void c_write_stderr(int trusted, const char *buf, int len)
|
|
{
|
|
int i;
|
|
for (i = 0; i < len; i++)
|
|
if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
|
|
fputc(buf[i], stderr);
|
|
}
|
|
|
|
static void c_write(Ssh ssh, const char *buf, int len)
|
|
{
|
|
if (flags & FLAG_STDERR)
|
|
c_write_stderr(1, buf, len);
|
|
else
|
|
from_backend(ssh->frontend, 1, buf, len);
|
|
}
|
|
|
|
static void c_write_untrusted(Ssh ssh, const char *buf, int len)
|
|
{
|
|
if (flags & FLAG_STDERR)
|
|
c_write_stderr(0, buf, len);
|
|
else
|
|
from_backend_untrusted(ssh->frontend, buf, len);
|
|
}
|
|
|
|
static void c_write_str(Ssh ssh, const char *buf)
|
|
{
|
|
c_write(ssh, buf, strlen(buf));
|
|
}
|
|
|
|
static void ssh_free_packet(struct Packet *pkt)
|
|
{
|
|
sfree(pkt->data);
|
|
sfree(pkt);
|
|
}
|
|
static struct Packet *ssh_new_packet(void)
|
|
{
|
|
struct Packet *pkt = snew(struct Packet);
|
|
|
|
pkt->body = pkt->data = NULL;
|
|
pkt->maxlen = 0;
|
|
pkt->logmode = PKTLOG_EMIT;
|
|
pkt->nblanks = 0;
|
|
pkt->blanks = NULL;
|
|
|
|
return pkt;
|
|
}
|
|
|
|
/*
|
|
* Collect incoming data in the incoming packet buffer.
|
|
* Decipher and verify the packet when it is completely read.
|
|
* Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
|
|
* Update the *data and *datalen variables.
|
|
* Return a Packet structure when a packet is completed.
|
|
*/
|
|
static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
|
|
{
|
|
struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
|
|
|
|
crBegin(ssh->ssh1_rdpkt_crstate);
|
|
|
|
st->pktin = ssh_new_packet();
|
|
|
|
st->pktin->type = 0;
|
|
st->pktin->length = 0;
|
|
|
|
for (st->i = st->len = 0; st->i < 4; st->i++) {
|
|
while ((*datalen) == 0)
|
|
crReturn(NULL);
|
|
st->len = (st->len << 8) + **data;
|
|
(*data)++, (*datalen)--;
|
|
}
|
|
|
|
st->pad = 8 - (st->len % 8);
|
|
st->biglen = st->len + st->pad;
|
|
st->pktin->length = st->len - 5;
|
|
|
|
if (st->biglen < 0) {
|
|
bombout(("Extremely large packet length from server suggests"
|
|
" data stream corruption"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
|
|
st->pktin->maxlen = st->biglen;
|
|
st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
|
|
|
|
st->to_read = st->biglen;
|
|
st->p = st->pktin->data;
|
|
while (st->to_read > 0) {
|
|
st->chunk = st->to_read;
|
|
while ((*datalen) == 0)
|
|
crReturn(NULL);
|
|
if (st->chunk > (*datalen))
|
|
st->chunk = (*datalen);
|
|
memcpy(st->p, *data, st->chunk);
|
|
*data += st->chunk;
|
|
*datalen -= st->chunk;
|
|
st->p += st->chunk;
|
|
st->to_read -= st->chunk;
|
|
}
|
|
|
|
if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
|
|
st->biglen, NULL)) {
|
|
bombout(("Network attack (CRC compensation) detected!"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
|
|
if (ssh->cipher)
|
|
ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
|
|
|
|
st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
|
|
st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
|
|
if (st->gotcrc != st->realcrc) {
|
|
bombout(("Incorrect CRC received on packet"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
|
|
st->pktin->body = st->pktin->data + st->pad + 1;
|
|
st->pktin->savedpos = 0;
|
|
|
|
if (ssh->v1_compressing) {
|
|
unsigned char *decompblk;
|
|
int decomplen;
|
|
if (!zlib_decompress_block(ssh->sc_comp_ctx,
|
|
st->pktin->body - 1, st->pktin->length + 1,
|
|
&decompblk, &decomplen)) {
|
|
bombout(("Zlib decompression encountered invalid data"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
|
|
if (st->pktin->maxlen < st->pad + decomplen) {
|
|
st->pktin->maxlen = st->pad + decomplen;
|
|
st->pktin->data = sresize(st->pktin->data,
|
|
st->pktin->maxlen + APIEXTRA,
|
|
unsigned char);
|
|
st->pktin->body = st->pktin->data + st->pad + 1;
|
|
}
|
|
|
|
memcpy(st->pktin->body - 1, decompblk, decomplen);
|
|
sfree(decompblk);
|
|
st->pktin->length = decomplen - 1;
|
|
}
|
|
|
|
st->pktin->type = st->pktin->body[-1];
|
|
|
|
/*
|
|
* Log incoming packet, possibly omitting sensitive fields.
|
|
*/
|
|
if (ssh->logctx) {
|
|
int nblanks = 0;
|
|
struct logblank_t blank;
|
|
if (ssh->cfg.logomitdata) {
|
|
int do_blank = FALSE, blank_prefix = 0;
|
|
/* "Session data" packets - omit the data field */
|
|
if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
|
|
(st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
|
|
do_blank = TRUE; blank_prefix = 4;
|
|
} else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
|
|
do_blank = TRUE; blank_prefix = 8;
|
|
}
|
|
if (do_blank) {
|
|
blank.offset = blank_prefix;
|
|
blank.len = st->pktin->length;
|
|
blank.type = PKTLOG_OMIT;
|
|
nblanks = 1;
|
|
}
|
|
}
|
|
log_packet(ssh->logctx,
|
|
PKT_INCOMING, st->pktin->type,
|
|
ssh1_pkt_type(st->pktin->type),
|
|
st->pktin->body, st->pktin->length,
|
|
nblanks, &blank, NULL);
|
|
}
|
|
|
|
crFinish(st->pktin);
|
|
}
|
|
|
|
static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
|
|
{
|
|
struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
|
|
|
|
crBegin(ssh->ssh2_rdpkt_crstate);
|
|
|
|
st->pktin = ssh_new_packet();
|
|
|
|
st->pktin->type = 0;
|
|
st->pktin->length = 0;
|
|
if (ssh->sccipher)
|
|
st->cipherblk = ssh->sccipher->blksize;
|
|
else
|
|
st->cipherblk = 8;
|
|
if (st->cipherblk < 8)
|
|
st->cipherblk = 8;
|
|
st->maclen = ssh->scmac ? ssh->scmac->len : 0;
|
|
|
|
if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
|
|
ssh->scmac) {
|
|
/*
|
|
* When dealing with a CBC-mode cipher, we want to avoid the
|
|
* possibility of an attacker's tweaking the ciphertext stream
|
|
* so as to cause us to feed the same block to the block
|
|
* cipher more than once and thus leak information
|
|
* (VU#958563). The way we do this is not to take any
|
|
* decisions on the basis of anything we've decrypted until
|
|
* we've verified it with a MAC. That includes the packet
|
|
* length, so we just read data and check the MAC repeatedly,
|
|
* and when the MAC passes, see if the length we've got is
|
|
* plausible.
|
|
*/
|
|
|
|
/* May as well allocate the whole lot now. */
|
|
st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
|
|
unsigned char);
|
|
|
|
/* Read an amount corresponding to the MAC. */
|
|
for (st->i = 0; st->i < st->maclen; st->i++) {
|
|
while ((*datalen) == 0)
|
|
crReturn(NULL);
|
|
st->pktin->data[st->i] = *(*data)++;
|
|
(*datalen)--;
|
|
}
|
|
|
|
st->packetlen = 0;
|
|
{
|
|
unsigned char seq[4];
|
|
ssh->scmac->start(ssh->sc_mac_ctx);
|
|
PUT_32BIT(seq, st->incoming_sequence);
|
|
ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
|
|
}
|
|
|
|
for (;;) { /* Once around this loop per cipher block. */
|
|
/* Read another cipher-block's worth, and tack it onto the end. */
|
|
for (st->i = 0; st->i < st->cipherblk; st->i++) {
|
|
while ((*datalen) == 0)
|
|
crReturn(NULL);
|
|
st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
|
|
(*datalen)--;
|
|
}
|
|
/* Decrypt one more block (a little further back in the stream). */
|
|
ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
|
|
st->pktin->data + st->packetlen,
|
|
st->cipherblk);
|
|
/* Feed that block to the MAC. */
|
|
ssh->scmac->bytes(ssh->sc_mac_ctx,
|
|
st->pktin->data + st->packetlen, st->cipherblk);
|
|
st->packetlen += st->cipherblk;
|
|
/* See if that gives us a valid packet. */
|
|
if (ssh->scmac->verresult(ssh->sc_mac_ctx,
|
|
st->pktin->data + st->packetlen) &&
|
|
(st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
|
|
break;
|
|
if (st->packetlen >= OUR_V2_PACKETLIMIT) {
|
|
bombout(("No valid incoming packet found"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
}
|
|
st->pktin->maxlen = st->packetlen + st->maclen;
|
|
st->pktin->data = sresize(st->pktin->data,
|
|
st->pktin->maxlen + APIEXTRA,
|
|
unsigned char);
|
|
} else {
|
|
st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
|
|
|
|
/*
|
|
* Acquire and decrypt the first block of the packet. This will
|
|
* contain the length and padding details.
|
|
*/
|
|
for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
|
|
while ((*datalen) == 0)
|
|
crReturn(NULL);
|
|
st->pktin->data[st->i] = *(*data)++;
|
|
(*datalen)--;
|
|
}
|
|
|
|
if (ssh->sccipher)
|
|
ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
|
|
st->pktin->data, st->cipherblk);
|
|
|
|
/*
|
|
* Now get the length figure.
|
|
*/
|
|
st->len = GET_32BIT(st->pktin->data);
|
|
|
|
/*
|
|
* _Completely_ silly lengths should be stomped on before they
|
|
* do us any more damage.
|
|
*/
|
|
if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
|
|
(st->len + 4) % st->cipherblk != 0) {
|
|
bombout(("Incoming packet was garbled on decryption"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
|
|
/*
|
|
* So now we can work out the total packet length.
|
|
*/
|
|
st->packetlen = st->len + 4;
|
|
|
|
/*
|
|
* Allocate memory for the rest of the packet.
|
|
*/
|
|
st->pktin->maxlen = st->packetlen + st->maclen;
|
|
st->pktin->data = sresize(st->pktin->data,
|
|
st->pktin->maxlen + APIEXTRA,
|
|
unsigned char);
|
|
|
|
/*
|
|
* Read and decrypt the remainder of the packet.
|
|
*/
|
|
for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
|
|
st->i++) {
|
|
while ((*datalen) == 0)
|
|
crReturn(NULL);
|
|
st->pktin->data[st->i] = *(*data)++;
|
|
(*datalen)--;
|
|
}
|
|
/* Decrypt everything _except_ the MAC. */
|
|
if (ssh->sccipher)
|
|
ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
|
|
st->pktin->data + st->cipherblk,
|
|
st->packetlen - st->cipherblk);
|
|
|
|
/*
|
|
* Check the MAC.
|
|
*/
|
|
if (ssh->scmac
|
|
&& !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
|
|
st->len + 4, st->incoming_sequence)) {
|
|
bombout(("Incorrect MAC received on packet"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
}
|
|
/* Get and sanity-check the amount of random padding. */
|
|
st->pad = st->pktin->data[4];
|
|
if (st->pad < 4 || st->len - st->pad < 1) {
|
|
bombout(("Invalid padding length on received packet"));
|
|
ssh_free_packet(st->pktin);
|
|
crStop(NULL);
|
|
}
|
|
/*
|
|
* This enables us to deduce the payload length.
|
|
*/
|
|
st->payload = st->len - st->pad - 1;
|
|
|
|
st->pktin->length = st->payload + 5;
|
|
st->pktin->encrypted_len = st->packetlen;
|
|
|
|
st->pktin->sequence = st->incoming_sequence++;
|
|
|
|
/*
|
|
* Decompress packet payload.
|
|
*/
|
|
{
|
|
unsigned char *newpayload;
|
|
int newlen;
|
|
if (ssh->sccomp &&
|
|
ssh->sccomp->decompress(ssh->sc_comp_ctx,
|
|
st->pktin->data + 5, st->pktin->length - 5,
|
|
&newpayload, &newlen)) {
|
|
if (st->pktin->maxlen < newlen + 5) {
|
|
st->pktin->maxlen = newlen + 5;
|
|
st->pktin->data = sresize(st->pktin->data,
|
|
st->pktin->maxlen + APIEXTRA,
|
|
unsigned char);
|
|
}
|
|
st->pktin->length = 5 + newlen;
|
|
memcpy(st->pktin->data + 5, newpayload, newlen);
|
|
sfree(newpayload);
|
|
}
|
|
}
|
|
|
|
st->pktin->savedpos = 6;
|
|
st->pktin->body = st->pktin->data;
|
|
st->pktin->type = st->pktin->data[5];
|
|
|
|
/*
|
|
* Log incoming packet, possibly omitting sensitive fields.
|
|
*/
|
|
if (ssh->logctx) {
|
|
int nblanks = 0;
|
|
struct logblank_t blank;
|
|
if (ssh->cfg.logomitdata) {
|
|
int do_blank = FALSE, blank_prefix = 0;
|
|
/* "Session data" packets - omit the data field */
|
|
if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
|
|
do_blank = TRUE; blank_prefix = 8;
|
|
} else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
|
|
do_blank = TRUE; blank_prefix = 12;
|
|
}
|
|
if (do_blank) {
|
|
blank.offset = blank_prefix;
|
|
blank.len = (st->pktin->length-6) - blank_prefix;
|
|
blank.type = PKTLOG_OMIT;
|
|
nblanks = 1;
|
|
}
|
|
}
|
|
log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
|
|
ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
|
|
st->pktin->type),
|
|
st->pktin->data+6, st->pktin->length-6,
|
|
nblanks, &blank, &st->pktin->sequence);
|
|
}
|
|
|
|
crFinish(st->pktin);
|
|
}
|
|
|
|
static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
|
|
{
|
|
int pad, biglen, i, pktoffs;
|
|
unsigned long crc;
|
|
#ifdef __SC__
|
|
/*
|
|
* XXX various versions of SC (including 8.8.4) screw up the
|
|
* register allocation in this function and use the same register
|
|
* (D6) for len and as a temporary, with predictable results. The
|
|
* following sledgehammer prevents this.
|
|
*/
|
|
volatile
|
|
#endif
|
|
int len;
|
|
|
|
if (ssh->logctx)
|
|
log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
|
|
ssh1_pkt_type(pkt->data[12]),
|
|
pkt->body, pkt->length - (pkt->body - pkt->data),
|
|
pkt->nblanks, pkt->blanks, NULL);
|
|
sfree(pkt->blanks); pkt->blanks = NULL;
|
|
pkt->nblanks = 0;
|
|
|
|
if (ssh->v1_compressing) {
|
|
unsigned char *compblk;
|
|
int complen;
|
|
zlib_compress_block(ssh->cs_comp_ctx,
|
|
pkt->data + 12, pkt->length - 12,
|
|
&compblk, &complen);
|
|
ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
|
|
memcpy(pkt->data + 12, compblk, complen);
|
|
sfree(compblk);
|
|
pkt->length = complen + 12;
|
|
}
|
|
|
|
ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
|
|
pkt->length += 4;
|
|
len = pkt->length - 4 - 8; /* len(type+data+CRC) */
|
|
pad = 8 - (len % 8);
|
|
pktoffs = 8 - pad;
|
|
biglen = len + pad; /* len(padding+type+data+CRC) */
|
|
|
|
for (i = pktoffs; i < 4+8; i++)
|
|
pkt->data[i] = random_byte();
|
|
crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
|
|
PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
|
|
PUT_32BIT(pkt->data + pktoffs, len);
|
|
|
|
if (ssh->cipher)
|
|
ssh->cipher->encrypt(ssh->v1_cipher_ctx,
|
|
pkt->data + pktoffs + 4, biglen);
|
|
|
|
if (offset_p) *offset_p = pktoffs;
|
|
return biglen + 4; /* len(length+padding+type+data+CRC) */
|
|
}
|
|
|
|
static int s_write(Ssh ssh, void *data, int len)
|
|
{
|
|
if (ssh->logctx)
|
|
log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
|
|
0, NULL, NULL);
|
|
return sk_write(ssh->s, (char *)data, len);
|
|
}
|
|
|
|
static void s_wrpkt(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
int len, backlog, offset;
|
|
len = s_wrpkt_prepare(ssh, pkt, &offset);
|
|
backlog = s_write(ssh, pkt->data + offset, len);
|
|
if (backlog > SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(ssh, 1, backlog);
|
|
ssh_free_packet(pkt);
|
|
}
|
|
|
|
static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
int len, offset;
|
|
len = s_wrpkt_prepare(ssh, pkt, &offset);
|
|
if (ssh->deferred_len + len > ssh->deferred_size) {
|
|
ssh->deferred_size = ssh->deferred_len + len + 128;
|
|
ssh->deferred_send_data = sresize(ssh->deferred_send_data,
|
|
ssh->deferred_size,
|
|
unsigned char);
|
|
}
|
|
memcpy(ssh->deferred_send_data + ssh->deferred_len,
|
|
pkt->data + offset, len);
|
|
ssh->deferred_len += len;
|
|
ssh_free_packet(pkt);
|
|
}
|
|
|
|
/*
|
|
* Construct a SSH-1 packet with the specified contents.
|
|
* (This all-at-once interface used to be the only one, but now SSH-1
|
|
* packets can also be constructed incrementally.)
|
|
*/
|
|
static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
|
|
{
|
|
int argtype;
|
|
Bignum bn;
|
|
struct Packet *pkt;
|
|
|
|
pkt = ssh1_pkt_init(pkttype);
|
|
|
|
while ((argtype = va_arg(ap, int)) != PKT_END) {
|
|
unsigned char *argp, argchar;
|
|
char *sargp;
|
|
unsigned long argint;
|
|
int arglen;
|
|
switch (argtype) {
|
|
/* Actual fields in the packet */
|
|
case PKT_INT:
|
|
argint = va_arg(ap, int);
|
|
ssh_pkt_adduint32(pkt, argint);
|
|
break;
|
|
case PKT_CHAR:
|
|
argchar = (unsigned char) va_arg(ap, int);
|
|
ssh_pkt_addbyte(pkt, argchar);
|
|
break;
|
|
case PKT_DATA:
|
|
argp = va_arg(ap, unsigned char *);
|
|
arglen = va_arg(ap, int);
|
|
ssh_pkt_adddata(pkt, argp, arglen);
|
|
break;
|
|
case PKT_STR:
|
|
sargp = va_arg(ap, char *);
|
|
ssh_pkt_addstring(pkt, sargp);
|
|
break;
|
|
case PKT_BIGNUM:
|
|
bn = va_arg(ap, Bignum);
|
|
ssh1_pkt_addmp(pkt, bn);
|
|
break;
|
|
/* Tokens for modifications to packet logging */
|
|
case PKTT_PASSWORD:
|
|
dont_log_password(ssh, pkt, PKTLOG_BLANK);
|
|
break;
|
|
case PKTT_DATA:
|
|
dont_log_data(ssh, pkt, PKTLOG_OMIT);
|
|
break;
|
|
case PKTT_OTHER:
|
|
end_log_omission(ssh, pkt);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return pkt;
|
|
}
|
|
|
|
static void send_packet(Ssh ssh, int pkttype, ...)
|
|
{
|
|
struct Packet *pkt;
|
|
va_list ap;
|
|
va_start(ap, pkttype);
|
|
pkt = construct_packet(ssh, pkttype, ap);
|
|
va_end(ap);
|
|
s_wrpkt(ssh, pkt);
|
|
}
|
|
|
|
static void defer_packet(Ssh ssh, int pkttype, ...)
|
|
{
|
|
struct Packet *pkt;
|
|
va_list ap;
|
|
va_start(ap, pkttype);
|
|
pkt = construct_packet(ssh, pkttype, ap);
|
|
va_end(ap);
|
|
s_wrpkt_defer(ssh, pkt);
|
|
}
|
|
|
|
static int ssh_versioncmp(char *a, char *b)
|
|
{
|
|
char *ae, *be;
|
|
unsigned long av, bv;
|
|
|
|
av = strtoul(a, &ae, 10);
|
|
bv = strtoul(b, &be, 10);
|
|
if (av != bv)
|
|
return (av < bv ? -1 : +1);
|
|
if (*ae == '.')
|
|
ae++;
|
|
if (*be == '.')
|
|
be++;
|
|
av = strtoul(ae, &ae, 10);
|
|
bv = strtoul(be, &be, 10);
|
|
if (av != bv)
|
|
return (av < bv ? -1 : +1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Utility routines for putting an SSH-protocol `string' and
|
|
* `uint32' into a hash state.
|
|
*/
|
|
static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
|
|
{
|
|
unsigned char lenblk[4];
|
|
PUT_32BIT(lenblk, len);
|
|
h->bytes(s, lenblk, 4);
|
|
h->bytes(s, str, len);
|
|
}
|
|
|
|
static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
|
|
{
|
|
unsigned char intblk[4];
|
|
PUT_32BIT(intblk, i);
|
|
h->bytes(s, intblk, 4);
|
|
}
|
|
|
|
/*
|
|
* Packet construction functions. Mostly shared between SSH-1 and SSH-2.
|
|
*/
|
|
static void ssh_pkt_ensure(struct Packet *pkt, int length)
|
|
{
|
|
if (pkt->maxlen < length) {
|
|
unsigned char *body = pkt->body;
|
|
int offset = body ? body - pkt->data : 0;
|
|
pkt->maxlen = length + 256;
|
|
pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
|
|
if (body) pkt->body = pkt->data + offset;
|
|
}
|
|
}
|
|
static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
|
|
{
|
|
if (pkt->logmode != PKTLOG_EMIT) {
|
|
pkt->nblanks++;
|
|
pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
|
|
assert(pkt->body);
|
|
pkt->blanks[pkt->nblanks-1].offset = pkt->length -
|
|
(pkt->body - pkt->data);
|
|
pkt->blanks[pkt->nblanks-1].len = len;
|
|
pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
|
|
}
|
|
pkt->length += len;
|
|
ssh_pkt_ensure(pkt, pkt->length);
|
|
memcpy(pkt->data + pkt->length - len, data, len);
|
|
}
|
|
static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
|
|
{
|
|
ssh_pkt_adddata(pkt, &byte, 1);
|
|
}
|
|
static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
|
|
{
|
|
ssh_pkt_adddata(pkt, &value, 1);
|
|
}
|
|
static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
|
|
{
|
|
unsigned char x[4];
|
|
PUT_32BIT(x, value);
|
|
ssh_pkt_adddata(pkt, x, 4);
|
|
}
|
|
static void ssh_pkt_addstring_start(struct Packet *pkt)
|
|
{
|
|
ssh_pkt_adduint32(pkt, 0);
|
|
pkt->savedpos = pkt->length;
|
|
}
|
|
static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
|
|
{
|
|
ssh_pkt_adddata(pkt, data, strlen(data));
|
|
PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
|
|
}
|
|
static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
|
|
{
|
|
ssh_pkt_adddata(pkt, data, len);
|
|
PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
|
|
}
|
|
static void ssh_pkt_addstring(struct Packet *pkt, char *data)
|
|
{
|
|
ssh_pkt_addstring_start(pkt);
|
|
ssh_pkt_addstring_str(pkt, data);
|
|
}
|
|
static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
|
|
{
|
|
int len = ssh1_bignum_length(b);
|
|
unsigned char *data = snewn(len, unsigned char);
|
|
(void) ssh1_write_bignum(data, b);
|
|
ssh_pkt_adddata(pkt, data, len);
|
|
sfree(data);
|
|
}
|
|
static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
|
|
{
|
|
unsigned char *p;
|
|
int i, n = (bignum_bitcount(b) + 7) / 8;
|
|
p = snewn(n + 1, unsigned char);
|
|
p[0] = 0;
|
|
for (i = 1; i <= n; i++)
|
|
p[i] = bignum_byte(b, n - i);
|
|
i = 0;
|
|
while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
|
|
i++;
|
|
memmove(p, p + i, n + 1 - i);
|
|
*len = n + 1 - i;
|
|
return p;
|
|
}
|
|
static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
|
|
{
|
|
unsigned char *p;
|
|
int len;
|
|
p = ssh2_mpint_fmt(b, &len);
|
|
ssh_pkt_addstring_start(pkt);
|
|
ssh_pkt_addstring_data(pkt, (char *)p, len);
|
|
sfree(p);
|
|
}
|
|
|
|
static struct Packet *ssh1_pkt_init(int pkt_type)
|
|
{
|
|
struct Packet *pkt = ssh_new_packet();
|
|
pkt->length = 4 + 8; /* space for length + max padding */
|
|
ssh_pkt_addbyte(pkt, pkt_type);
|
|
pkt->body = pkt->data + pkt->length;
|
|
return pkt;
|
|
}
|
|
|
|
/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
|
|
#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
|
|
#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
|
|
#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
|
|
#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
|
|
#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
|
|
#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
|
|
#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
|
|
#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
|
|
|
|
static struct Packet *ssh2_pkt_init(int pkt_type)
|
|
{
|
|
struct Packet *pkt = ssh_new_packet();
|
|
pkt->length = 5; /* space for packet length + padding length */
|
|
pkt->forcepad = 0;
|
|
ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
|
|
pkt->body = pkt->data + pkt->length; /* after packet type */
|
|
return pkt;
|
|
}
|
|
|
|
/*
|
|
* Construct an SSH-2 final-form packet: compress it, encrypt it,
|
|
* put the MAC on it. Final packet, ready to be sent, is stored in
|
|
* pkt->data. Total length is returned.
|
|
*/
|
|
static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
int cipherblk, maclen, padding, i;
|
|
|
|
if (ssh->logctx)
|
|
log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
|
|
ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
|
|
pkt->body, pkt->length - (pkt->body - pkt->data),
|
|
pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
|
|
sfree(pkt->blanks); pkt->blanks = NULL;
|
|
pkt->nblanks = 0;
|
|
|
|
/*
|
|
* Compress packet payload.
|
|
*/
|
|
{
|
|
unsigned char *newpayload;
|
|
int newlen;
|
|
if (ssh->cscomp &&
|
|
ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
|
|
pkt->length - 5,
|
|
&newpayload, &newlen)) {
|
|
pkt->length = 5;
|
|
ssh2_pkt_adddata(pkt, newpayload, newlen);
|
|
sfree(newpayload);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Add padding. At least four bytes, and must also bring total
|
|
* length (minus MAC) up to a multiple of the block size.
|
|
* If pkt->forcepad is set, make sure the packet is at least that size
|
|
* after padding.
|
|
*/
|
|
cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
|
|
cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
|
|
padding = 4;
|
|
if (pkt->length + padding < pkt->forcepad)
|
|
padding = pkt->forcepad - pkt->length;
|
|
padding +=
|
|
(cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
|
|
assert(padding <= 255);
|
|
maclen = ssh->csmac ? ssh->csmac->len : 0;
|
|
ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
|
|
pkt->data[4] = padding;
|
|
for (i = 0; i < padding; i++)
|
|
pkt->data[pkt->length + i] = random_byte();
|
|
PUT_32BIT(pkt->data, pkt->length + padding - 4);
|
|
if (ssh->csmac)
|
|
ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
|
|
pkt->length + padding,
|
|
ssh->v2_outgoing_sequence);
|
|
ssh->v2_outgoing_sequence++; /* whether or not we MACed */
|
|
|
|
if (ssh->cscipher)
|
|
ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
|
|
pkt->data, pkt->length + padding);
|
|
|
|
pkt->encrypted_len = pkt->length + padding;
|
|
|
|
/* Ready-to-send packet starts at pkt->data. We return length. */
|
|
return pkt->length + padding + maclen;
|
|
}
|
|
|
|
/*
|
|
* Routines called from the main SSH code to send packets. There
|
|
* are quite a few of these, because we have two separate
|
|
* mechanisms for delaying the sending of packets:
|
|
*
|
|
* - In order to send an IGNORE message and a password message in
|
|
* a single fixed-length blob, we require the ability to
|
|
* concatenate the encrypted forms of those two packets _into_ a
|
|
* single blob and then pass it to our <network.h> transport
|
|
* layer in one go. Hence, there's a deferment mechanism which
|
|
* works after packet encryption.
|
|
*
|
|
* - In order to avoid sending any connection-layer messages
|
|
* during repeat key exchange, we have to queue up any such
|
|
* outgoing messages _before_ they are encrypted (and in
|
|
* particular before they're allocated sequence numbers), and
|
|
* then send them once we've finished.
|
|
*
|
|
* I call these mechanisms `defer' and `queue' respectively, so as
|
|
* to distinguish them reasonably easily.
|
|
*
|
|
* The functions send_noqueue() and defer_noqueue() free the packet
|
|
* structure they are passed. Every outgoing packet goes through
|
|
* precisely one of these functions in its life; packets passed to
|
|
* ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
|
|
* these or get queued, and then when the queue is later emptied
|
|
* the packets are all passed to defer_noqueue().
|
|
*
|
|
* When using a CBC-mode cipher, it's necessary to ensure that an
|
|
* attacker can't provide data to be encrypted using an IV that they
|
|
* know. We ensure this by prefixing each packet that might contain
|
|
* user data with an SSH_MSG_IGNORE. This is done using the deferral
|
|
* mechanism, so in this case send_noqueue() ends up redirecting to
|
|
* defer_noqueue(). If you don't like this inefficiency, don't use
|
|
* CBC.
|
|
*/
|
|
|
|
static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
|
|
static void ssh_pkt_defersend(Ssh);
|
|
|
|
/*
|
|
* Send an SSH-2 packet immediately, without queuing or deferring.
|
|
*/
|
|
static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
int len;
|
|
int backlog;
|
|
if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
|
|
/* We need to send two packets, so use the deferral mechanism. */
|
|
ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
|
|
ssh_pkt_defersend(ssh);
|
|
return;
|
|
}
|
|
len = ssh2_pkt_construct(ssh, pkt);
|
|
backlog = s_write(ssh, pkt->data, len);
|
|
if (backlog > SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(ssh, 1, backlog);
|
|
|
|
ssh->outgoing_data_size += pkt->encrypted_len;
|
|
if (!ssh->kex_in_progress &&
|
|
ssh->max_data_size != 0 &&
|
|
ssh->outgoing_data_size > ssh->max_data_size)
|
|
do_ssh2_transport(ssh, "too much data sent", -1, NULL);
|
|
|
|
ssh_free_packet(pkt);
|
|
}
|
|
|
|
/*
|
|
* Defer an SSH-2 packet.
|
|
*/
|
|
static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
|
|
{
|
|
int len;
|
|
if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
|
|
ssh->deferred_len == 0 && !noignore) {
|
|
/*
|
|
* Interpose an SSH_MSG_IGNORE to ensure that user data don't
|
|
* get encrypted with a known IV.
|
|
*/
|
|
struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
|
|
ssh2_pkt_addstring_start(ipkt);
|
|
ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
|
|
}
|
|
len = ssh2_pkt_construct(ssh, pkt);
|
|
if (ssh->deferred_len + len > ssh->deferred_size) {
|
|
ssh->deferred_size = ssh->deferred_len + len + 128;
|
|
ssh->deferred_send_data = sresize(ssh->deferred_send_data,
|
|
ssh->deferred_size,
|
|
unsigned char);
|
|
}
|
|
memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
|
|
ssh->deferred_len += len;
|
|
ssh->deferred_data_size += pkt->encrypted_len;
|
|
ssh_free_packet(pkt);
|
|
}
|
|
|
|
/*
|
|
* Queue an SSH-2 packet.
|
|
*/
|
|
static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
assert(ssh->queueing);
|
|
|
|
if (ssh->queuelen >= ssh->queuesize) {
|
|
ssh->queuesize = ssh->queuelen + 32;
|
|
ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
|
|
}
|
|
|
|
ssh->queue[ssh->queuelen++] = pkt;
|
|
}
|
|
|
|
/*
|
|
* Either queue or send a packet, depending on whether queueing is
|
|
* set.
|
|
*/
|
|
static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
if (ssh->queueing)
|
|
ssh2_pkt_queue(ssh, pkt);
|
|
else
|
|
ssh2_pkt_send_noqueue(ssh, pkt);
|
|
}
|
|
|
|
/*
|
|
* Either queue or defer a packet, depending on whether queueing is
|
|
* set.
|
|
*/
|
|
static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
|
|
{
|
|
if (ssh->queueing)
|
|
ssh2_pkt_queue(ssh, pkt);
|
|
else
|
|
ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
|
|
}
|
|
|
|
/*
|
|
* Send the whole deferred data block constructed by
|
|
* ssh2_pkt_defer() or SSH-1's defer_packet().
|
|
*
|
|
* The expected use of the defer mechanism is that you call
|
|
* ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
|
|
* not currently queueing, this simply sets up deferred_send_data
|
|
* and then sends it. If we _are_ currently queueing, the calls to
|
|
* ssh2_pkt_defer() put the deferred packets on to the queue
|
|
* instead, and therefore ssh_pkt_defersend() has no deferred data
|
|
* to send. Hence, there's no need to make it conditional on
|
|
* ssh->queueing.
|
|
*/
|
|
static void ssh_pkt_defersend(Ssh ssh)
|
|
{
|
|
int backlog;
|
|
backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
|
|
ssh->deferred_len = ssh->deferred_size = 0;
|
|
sfree(ssh->deferred_send_data);
|
|
ssh->deferred_send_data = NULL;
|
|
if (backlog > SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(ssh, 1, backlog);
|
|
|
|
ssh->outgoing_data_size += ssh->deferred_data_size;
|
|
if (!ssh->kex_in_progress &&
|
|
ssh->max_data_size != 0 &&
|
|
ssh->outgoing_data_size > ssh->max_data_size)
|
|
do_ssh2_transport(ssh, "too much data sent", -1, NULL);
|
|
ssh->deferred_data_size = 0;
|
|
}
|
|
|
|
/*
|
|
* Send a packet whose length needs to be disguised (typically
|
|
* passwords or keyboard-interactive responses).
|
|
*/
|
|
static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
|
|
int padsize)
|
|
{
|
|
#if 0
|
|
if (0) {
|
|
/*
|
|
* The simplest way to do this is to adjust the
|
|
* variable-length padding field in the outgoing packet.
|
|
*
|
|
* Currently compiled out, because some Cisco SSH servers
|
|
* don't like excessively padded packets (bah, why's it
|
|
* always Cisco?)
|
|
*/
|
|
pkt->forcepad = padsize;
|
|
ssh2_pkt_send(ssh, pkt);
|
|
} else
|
|
#endif
|
|
{
|
|
/*
|
|
* If we can't do that, however, an alternative approach is
|
|
* to use the pkt_defer mechanism to bundle the packet
|
|
* tightly together with an SSH_MSG_IGNORE such that their
|
|
* combined length is a constant. So first we construct the
|
|
* final form of this packet and defer its sending.
|
|
*/
|
|
ssh2_pkt_defer(ssh, pkt);
|
|
|
|
/*
|
|
* Now construct an SSH_MSG_IGNORE which includes a string
|
|
* that's an exact multiple of the cipher block size. (If
|
|
* the cipher is NULL so that the block size is
|
|
* unavailable, we don't do this trick at all, because we
|
|
* gain nothing by it.)
|
|
*/
|
|
if (ssh->cscipher) {
|
|
int stringlen, i;
|
|
|
|
stringlen = (256 - ssh->deferred_len);
|
|
stringlen += ssh->cscipher->blksize - 1;
|
|
stringlen -= (stringlen % ssh->cscipher->blksize);
|
|
if (ssh->cscomp) {
|
|
/*
|
|
* Temporarily disable actual compression, so we
|
|
* can guarantee to get this string exactly the
|
|
* length we want it. The compression-disabling
|
|
* routine should return an integer indicating how
|
|
* many bytes we should adjust our string length
|
|
* by.
|
|
*/
|
|
stringlen -=
|
|
ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
|
|
}
|
|
pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
|
|
ssh2_pkt_addstring_start(pkt);
|
|
for (i = 0; i < stringlen; i++) {
|
|
char c = (char) random_byte();
|
|
ssh2_pkt_addstring_data(pkt, &c, 1);
|
|
}
|
|
ssh2_pkt_defer(ssh, pkt);
|
|
}
|
|
ssh_pkt_defersend(ssh);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send all queued SSH-2 packets. We send them by means of
|
|
* ssh2_pkt_defer_noqueue(), in case they included a pair of
|
|
* packets that needed to be lumped together.
|
|
*/
|
|
static void ssh2_pkt_queuesend(Ssh ssh)
|
|
{
|
|
int i;
|
|
|
|
assert(!ssh->queueing);
|
|
|
|
for (i = 0; i < ssh->queuelen; i++)
|
|
ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
|
|
ssh->queuelen = 0;
|
|
|
|
ssh_pkt_defersend(ssh);
|
|
}
|
|
|
|
#if 0
|
|
void bndebug(char *string, Bignum b)
|
|
{
|
|
unsigned char *p;
|
|
int i, len;
|
|
p = ssh2_mpint_fmt(b, &len);
|
|
debug(("%s", string));
|
|
for (i = 0; i < len; i++)
|
|
debug((" %02x", p[i]));
|
|
debug(("\n"));
|
|
sfree(p);
|
|
}
|
|
#endif
|
|
|
|
static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
|
|
{
|
|
unsigned char *p;
|
|
int len;
|
|
p = ssh2_mpint_fmt(b, &len);
|
|
hash_string(h, s, p, len);
|
|
sfree(p);
|
|
}
|
|
|
|
/*
|
|
* Packet decode functions for both SSH-1 and SSH-2.
|
|
*/
|
|
static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
|
|
{
|
|
unsigned long value;
|
|
if (pkt->length - pkt->savedpos < 4)
|
|
return 0; /* arrgh, no way to decline (FIXME?) */
|
|
value = GET_32BIT(pkt->body + pkt->savedpos);
|
|
pkt->savedpos += 4;
|
|
return value;
|
|
}
|
|
static int ssh2_pkt_getbool(struct Packet *pkt)
|
|
{
|
|
unsigned long value;
|
|
if (pkt->length - pkt->savedpos < 1)
|
|
return 0; /* arrgh, no way to decline (FIXME?) */
|
|
value = pkt->body[pkt->savedpos] != 0;
|
|
pkt->savedpos++;
|
|
return value;
|
|
}
|
|
static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
|
|
{
|
|
int len;
|
|
*p = NULL;
|
|
*length = 0;
|
|
if (pkt->length - pkt->savedpos < 4)
|
|
return;
|
|
len = GET_32BIT(pkt->body + pkt->savedpos);
|
|
if (len < 0)
|
|
return;
|
|
*length = len;
|
|
pkt->savedpos += 4;
|
|
if (pkt->length - pkt->savedpos < *length)
|
|
return;
|
|
*p = (char *)(pkt->body + pkt->savedpos);
|
|
pkt->savedpos += *length;
|
|
}
|
|
static void *ssh_pkt_getdata(struct Packet *pkt, int length)
|
|
{
|
|
if (pkt->length - pkt->savedpos < length)
|
|
return NULL;
|
|
pkt->savedpos += length;
|
|
return pkt->body + (pkt->savedpos - length);
|
|
}
|
|
static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
|
|
unsigned char **keystr)
|
|
{
|
|
int j;
|
|
|
|
j = makekey(pkt->body + pkt->savedpos,
|
|
pkt->length - pkt->savedpos,
|
|
key, keystr, 0);
|
|
|
|
if (j < 0)
|
|
return FALSE;
|
|
|
|
pkt->savedpos += j;
|
|
assert(pkt->savedpos < pkt->length);
|
|
|
|
return TRUE;
|
|
}
|
|
static Bignum ssh1_pkt_getmp(struct Packet *pkt)
|
|
{
|
|
int j;
|
|
Bignum b;
|
|
|
|
j = ssh1_read_bignum(pkt->body + pkt->savedpos,
|
|
pkt->length - pkt->savedpos, &b);
|
|
|
|
if (j < 0)
|
|
return NULL;
|
|
|
|
pkt->savedpos += j;
|
|
return b;
|
|
}
|
|
static Bignum ssh2_pkt_getmp(struct Packet *pkt)
|
|
{
|
|
char *p;
|
|
int length;
|
|
Bignum b;
|
|
|
|
ssh_pkt_getstring(pkt, &p, &length);
|
|
if (!p)
|
|
return NULL;
|
|
if (p[0] & 0x80)
|
|
return NULL;
|
|
b = bignum_from_bytes((unsigned char *)p, length);
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* Helper function to add an SSH-2 signature blob to a packet.
|
|
* Expects to be shown the public key blob as well as the signature
|
|
* blob. Normally works just like ssh2_pkt_addstring, but will
|
|
* fiddle with the signature packet if necessary for
|
|
* BUG_SSH2_RSA_PADDING.
|
|
*/
|
|
static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
|
|
void *pkblob_v, int pkblob_len,
|
|
void *sigblob_v, int sigblob_len)
|
|
{
|
|
unsigned char *pkblob = (unsigned char *)pkblob_v;
|
|
unsigned char *sigblob = (unsigned char *)sigblob_v;
|
|
|
|
/* dmemdump(pkblob, pkblob_len); */
|
|
/* dmemdump(sigblob, sigblob_len); */
|
|
|
|
/*
|
|
* See if this is in fact an ssh-rsa signature and a buggy
|
|
* server; otherwise we can just do this the easy way.
|
|
*/
|
|
if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
|
|
(GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
|
|
int pos, len, siglen;
|
|
|
|
/*
|
|
* Find the byte length of the modulus.
|
|
*/
|
|
|
|
pos = 4+7; /* skip over "ssh-rsa" */
|
|
pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
|
|
len = GET_32BIT(pkblob+pos); /* find length of modulus */
|
|
pos += 4; /* find modulus itself */
|
|
while (len > 0 && pkblob[pos] == 0)
|
|
len--, pos++;
|
|
/* debug(("modulus length is %d\n", len)); */
|
|
|
|
/*
|
|
* Now find the signature integer.
|
|
*/
|
|
pos = 4+7; /* skip over "ssh-rsa" */
|
|
siglen = GET_32BIT(sigblob+pos);
|
|
/* debug(("signature length is %d\n", siglen)); */
|
|
|
|
if (len != siglen) {
|
|
unsigned char newlen[4];
|
|
ssh2_pkt_addstring_start(pkt);
|
|
ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
|
|
/* dmemdump(sigblob, pos); */
|
|
pos += 4; /* point to start of actual sig */
|
|
PUT_32BIT(newlen, len);
|
|
ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
|
|
/* dmemdump(newlen, 4); */
|
|
newlen[0] = 0;
|
|
while (len-- > siglen) {
|
|
ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
|
|
/* dmemdump(newlen, 1); */
|
|
}
|
|
ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
|
|
/* dmemdump(sigblob+pos, siglen); */
|
|
return;
|
|
}
|
|
|
|
/* Otherwise fall through and do it the easy way. */
|
|
}
|
|
|
|
ssh2_pkt_addstring_start(pkt);
|
|
ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
|
|
}
|
|
|
|
/*
|
|
* Examine the remote side's version string and compare it against
|
|
* a list of known buggy implementations.
|
|
*/
|
|
static void ssh_detect_bugs(Ssh ssh, char *vstring)
|
|
{
|
|
char *imp; /* pointer to implementation part */
|
|
imp = vstring;
|
|
imp += strcspn(imp, "-");
|
|
if (*imp) imp++;
|
|
imp += strcspn(imp, "-");
|
|
if (*imp) imp++;
|
|
|
|
ssh->remote_bugs = 0;
|
|
|
|
/*
|
|
* General notes on server version strings:
|
|
* - Not all servers reporting "Cisco-1.25" have all the bugs listed
|
|
* here -- in particular, we've heard of one that's perfectly happy
|
|
* with SSH1_MSG_IGNOREs -- but this string never seems to change,
|
|
* so we can't distinguish them.
|
|
*/
|
|
if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_ignore1 == AUTO &&
|
|
(!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
|
|
!strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
|
|
!strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
|
|
!strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
|
|
/*
|
|
* These versions don't support SSH1_MSG_IGNORE, so we have
|
|
* to use a different defence against password length
|
|
* sniffing.
|
|
*/
|
|
ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
|
|
logevent("We believe remote version has SSH-1 ignore bug");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_plainpw1 == AUTO &&
|
|
(!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
|
|
/*
|
|
* These versions need a plain password sent; they can't
|
|
* handle having a null and a random length of data after
|
|
* the password.
|
|
*/
|
|
ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
|
|
logevent("We believe remote version needs a plain SSH-1 password");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_rsa1 == AUTO &&
|
|
(!strcmp(imp, "Cisco-1.25")))) {
|
|
/*
|
|
* These versions apparently have no clue whatever about
|
|
* RSA authentication and will panic and die if they see
|
|
* an AUTH_RSA message.
|
|
*/
|
|
ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
|
|
logevent("We believe remote version can't handle SSH-1 RSA authentication");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_hmac2 == AUTO &&
|
|
!wc_match("* VShell", imp) &&
|
|
(wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
|
|
wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
|
|
wc_match("2.1 *", imp)))) {
|
|
/*
|
|
* These versions have the HMAC bug.
|
|
*/
|
|
ssh->remote_bugs |= BUG_SSH2_HMAC;
|
|
logevent("We believe remote version has SSH-2 HMAC bug");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_derivekey2 == AUTO &&
|
|
!wc_match("* VShell", imp) &&
|
|
(wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
|
|
/*
|
|
* These versions have the key-derivation bug (failing to
|
|
* include the literal shared secret in the hashes that
|
|
* generate the keys).
|
|
*/
|
|
ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
|
|
logevent("We believe remote version has SSH-2 key-derivation bug");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_rsapad2 == AUTO &&
|
|
(wc_match("OpenSSH_2.[5-9]*", imp) ||
|
|
wc_match("OpenSSH_3.[0-2]*", imp)))) {
|
|
/*
|
|
* These versions have the SSH-2 RSA padding bug.
|
|
*/
|
|
ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
|
|
logevent("We believe remote version has SSH-2 RSA padding bug");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_pksessid2 == AUTO &&
|
|
wc_match("OpenSSH_2.[0-2]*", imp))) {
|
|
/*
|
|
* These versions have the SSH-2 session-ID bug in
|
|
* public-key authentication.
|
|
*/
|
|
ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
|
|
logevent("We believe remote version has SSH-2 public-key-session-ID bug");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_rekey2 == AUTO &&
|
|
(wc_match("DigiSSH_2.0", imp) ||
|
|
wc_match("OpenSSH_2.[0-4]*", imp) ||
|
|
wc_match("OpenSSH_2.5.[0-3]*", imp) ||
|
|
wc_match("Sun_SSH_1.0", imp) ||
|
|
wc_match("Sun_SSH_1.0.1", imp) ||
|
|
/* All versions <= 1.2.6 (they changed their format in 1.2.7) */
|
|
wc_match("WeOnlyDo-*", imp)))) {
|
|
/*
|
|
* These versions have the SSH-2 rekey bug.
|
|
*/
|
|
ssh->remote_bugs |= BUG_SSH2_REKEY;
|
|
logevent("We believe remote version has SSH-2 rekey bug");
|
|
}
|
|
|
|
if (ssh->cfg.sshbug_maxpkt2 == FORCE_ON ||
|
|
(ssh->cfg.sshbug_maxpkt2 == AUTO &&
|
|
(wc_match("1.36_sshlib GlobalSCAPE", imp) ||
|
|
wc_match("1.36 sshlib: GlobalScape", imp)))) {
|
|
/*
|
|
* This version ignores our makpkt and needs to be throttled.
|
|
*/
|
|
ssh->remote_bugs |= BUG_SSH2_MAXPKT;
|
|
logevent("We believe remote version ignores SSH-2 maximum packet size");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The `software version' part of an SSH version string is required
|
|
* to contain no spaces or minus signs.
|
|
*/
|
|
static void ssh_fix_verstring(char *str)
|
|
{
|
|
/* Eat "SSH-<protoversion>-". */
|
|
assert(*str == 'S'); str++;
|
|
assert(*str == 'S'); str++;
|
|
assert(*str == 'H'); str++;
|
|
assert(*str == '-'); str++;
|
|
while (*str && *str != '-') str++;
|
|
assert(*str == '-'); str++;
|
|
|
|
/* Convert minus signs and spaces in the remaining string into
|
|
* underscores. */
|
|
while (*str) {
|
|
if (*str == '-' || *str == ' ')
|
|
*str = '_';
|
|
str++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send an appropriate SSH version string.
|
|
*/
|
|
static void ssh_send_verstring(Ssh ssh, char *svers)
|
|
{
|
|
char *verstring;
|
|
|
|
if (ssh->version == 2) {
|
|
/*
|
|
* Construct a v2 version string.
|
|
*/
|
|
verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
|
|
} else {
|
|
/*
|
|
* Construct a v1 version string.
|
|
*/
|
|
verstring = dupprintf("SSH-%s-%s\012",
|
|
(ssh_versioncmp(svers, "1.5") <= 0 ?
|
|
svers : "1.5"),
|
|
sshver);
|
|
}
|
|
|
|
ssh_fix_verstring(verstring);
|
|
|
|
if (ssh->version == 2) {
|
|
size_t len;
|
|
/*
|
|
* Record our version string.
|
|
*/
|
|
len = strcspn(verstring, "\015\012");
|
|
ssh->v_c = snewn(len + 1, char);
|
|
memcpy(ssh->v_c, verstring, len);
|
|
ssh->v_c[len] = 0;
|
|
}
|
|
|
|
logeventf(ssh, "We claim version: %.*s",
|
|
strcspn(verstring, "\015\012"), verstring);
|
|
s_write(ssh, verstring, strlen(verstring));
|
|
sfree(verstring);
|
|
}
|
|
|
|
static int do_ssh_init(Ssh ssh, unsigned char c)
|
|
{
|
|
struct do_ssh_init_state {
|
|
int vslen;
|
|
char version[10];
|
|
char *vstring;
|
|
int vstrsize;
|
|
int i;
|
|
int proto1, proto2;
|
|
};
|
|
crState(do_ssh_init_state);
|
|
|
|
crBegin(ssh->do_ssh_init_crstate);
|
|
|
|
/* Search for a line beginning with the string "SSH-" in the input. */
|
|
for (;;) {
|
|
if (c != 'S') goto no;
|
|
crReturn(1);
|
|
if (c != 'S') goto no;
|
|
crReturn(1);
|
|
if (c != 'H') goto no;
|
|
crReturn(1);
|
|
if (c != '-') goto no;
|
|
break;
|
|
no:
|
|
while (c != '\012')
|
|
crReturn(1);
|
|
crReturn(1);
|
|
}
|
|
|
|
s->vstrsize = 16;
|
|
s->vstring = snewn(s->vstrsize, char);
|
|
strcpy(s->vstring, "SSH-");
|
|
s->vslen = 4;
|
|
s->i = 0;
|
|
while (1) {
|
|
crReturn(1); /* get another char */
|
|
if (s->vslen >= s->vstrsize - 1) {
|
|
s->vstrsize += 16;
|
|
s->vstring = sresize(s->vstring, s->vstrsize, char);
|
|
}
|
|
s->vstring[s->vslen++] = c;
|
|
if (s->i >= 0) {
|
|
if (c == '-') {
|
|
s->version[s->i] = '\0';
|
|
s->i = -1;
|
|
} else if (s->i < sizeof(s->version) - 1)
|
|
s->version[s->i++] = c;
|
|
} else if (c == '\012')
|
|
break;
|
|
}
|
|
|
|
ssh->agentfwd_enabled = FALSE;
|
|
ssh->rdpkt2_state.incoming_sequence = 0;
|
|
|
|
s->vstring[s->vslen] = 0;
|
|
s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
|
|
logeventf(ssh, "Server version: %s", s->vstring);
|
|
ssh_detect_bugs(ssh, s->vstring);
|
|
|
|
/*
|
|
* Decide which SSH protocol version to support.
|
|
*/
|
|
|
|
/* Anything strictly below "2.0" means protocol 1 is supported. */
|
|
s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
|
|
/* Anything greater or equal to "1.99" means protocol 2 is supported. */
|
|
s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
|
|
|
|
if (ssh->cfg.sshprot == 0 && !s->proto1) {
|
|
bombout(("SSH protocol version 1 required by user but not provided by server"));
|
|
crStop(0);
|
|
}
|
|
if (ssh->cfg.sshprot == 3 && !s->proto2) {
|
|
bombout(("SSH protocol version 2 required by user but not provided by server"));
|
|
crStop(0);
|
|
}
|
|
|
|
if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1))
|
|
ssh->version = 2;
|
|
else
|
|
ssh->version = 1;
|
|
|
|
logeventf(ssh, "Using SSH protocol version %d", ssh->version);
|
|
|
|
/* Send the version string, if we haven't already */
|
|
if (ssh->cfg.sshprot != 3)
|
|
ssh_send_verstring(ssh, s->version);
|
|
|
|
if (ssh->version == 2) {
|
|
size_t len;
|
|
/*
|
|
* Record their version string.
|
|
*/
|
|
len = strcspn(s->vstring, "\015\012");
|
|
ssh->v_s = snewn(len + 1, char);
|
|
memcpy(ssh->v_s, s->vstring, len);
|
|
ssh->v_s[len] = 0;
|
|
|
|
/*
|
|
* Initialise SSH-2 protocol.
|
|
*/
|
|
ssh->protocol = ssh2_protocol;
|
|
ssh2_protocol_setup(ssh);
|
|
ssh->s_rdpkt = ssh2_rdpkt;
|
|
} else {
|
|
/*
|
|
* Initialise SSH-1 protocol.
|
|
*/
|
|
ssh->protocol = ssh1_protocol;
|
|
ssh1_protocol_setup(ssh);
|
|
ssh->s_rdpkt = ssh1_rdpkt;
|
|
}
|
|
if (ssh->version == 2)
|
|
do_ssh2_transport(ssh, NULL, -1, NULL);
|
|
|
|
update_specials_menu(ssh->frontend);
|
|
ssh->state = SSH_STATE_BEFORE_SIZE;
|
|
ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
|
|
|
|
sfree(s->vstring);
|
|
|
|
crFinish(0);
|
|
}
|
|
|
|
static void ssh_process_incoming_data(Ssh ssh,
|
|
unsigned char **data, int *datalen)
|
|
{
|
|
struct Packet *pktin;
|
|
|
|
pktin = ssh->s_rdpkt(ssh, data, datalen);
|
|
if (pktin) {
|
|
ssh->protocol(ssh, NULL, 0, pktin);
|
|
ssh_free_packet(pktin);
|
|
}
|
|
}
|
|
|
|
static void ssh_queue_incoming_data(Ssh ssh,
|
|
unsigned char **data, int *datalen)
|
|
{
|
|
bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
|
|
*data += *datalen;
|
|
*datalen = 0;
|
|
}
|
|
|
|
static void ssh_process_queued_incoming_data(Ssh ssh)
|
|
{
|
|
void *vdata;
|
|
unsigned char *data;
|
|
int len, origlen;
|
|
|
|
while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
|
|
bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
|
|
data = vdata;
|
|
origlen = len;
|
|
|
|
while (!ssh->frozen && len > 0)
|
|
ssh_process_incoming_data(ssh, &data, &len);
|
|
|
|
if (origlen > len)
|
|
bufchain_consume(&ssh->queued_incoming_data, origlen - len);
|
|
}
|
|
}
|
|
|
|
static void ssh_set_frozen(Ssh ssh, int frozen)
|
|
{
|
|
if (ssh->s)
|
|
sk_set_frozen(ssh->s, frozen);
|
|
ssh->frozen = frozen;
|
|
}
|
|
|
|
static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
|
|
{
|
|
/* Log raw data, if we're in that mode. */
|
|
if (ssh->logctx)
|
|
log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
|
|
0, NULL, NULL);
|
|
|
|
crBegin(ssh->ssh_gotdata_crstate);
|
|
|
|
/*
|
|
* To begin with, feed the characters one by one to the
|
|
* protocol initialisation / selection function do_ssh_init().
|
|
* When that returns 0, we're done with the initial greeting
|
|
* exchange and can move on to packet discipline.
|
|
*/
|
|
while (1) {
|
|
int ret; /* need not be kept across crReturn */
|
|
if (datalen == 0)
|
|
crReturnV; /* more data please */
|
|
ret = do_ssh_init(ssh, *data);
|
|
data++;
|
|
datalen--;
|
|
if (ret == 0)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We emerge from that loop when the initial negotiation is
|
|
* over and we have selected an s_rdpkt function. Now pass
|
|
* everything to s_rdpkt, and then pass the resulting packets
|
|
* to the proper protocol handler.
|
|
*/
|
|
|
|
while (1) {
|
|
while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
|
|
if (ssh->frozen) {
|
|
ssh_queue_incoming_data(ssh, &data, &datalen);
|
|
/* This uses up all data and cannot cause anything interesting
|
|
* to happen; indeed, for anything to happen at all, we must
|
|
* return, so break out. */
|
|
break;
|
|
} else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
|
|
/* This uses up some or all data, and may freeze the
|
|
* session. */
|
|
ssh_process_queued_incoming_data(ssh);
|
|
} else {
|
|
/* This uses up some or all data, and may freeze the
|
|
* session. */
|
|
ssh_process_incoming_data(ssh, &data, &datalen);
|
|
}
|
|
/* FIXME this is probably EBW. */
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return;
|
|
}
|
|
/* We're out of data. Go and get some more. */
|
|
crReturnV;
|
|
}
|
|
crFinishV;
|
|
}
|
|
|
|
static int ssh_do_close(Ssh ssh, int notify_exit)
|
|
{
|
|
int ret = 0;
|
|
struct ssh_channel *c;
|
|
|
|
ssh->state = SSH_STATE_CLOSED;
|
|
expire_timer_context(ssh);
|
|
if (ssh->s) {
|
|
sk_close(ssh->s);
|
|
ssh->s = NULL;
|
|
if (notify_exit)
|
|
notify_remote_exit(ssh->frontend);
|
|
else
|
|
ret = 1;
|
|
}
|
|
/*
|
|
* Now we must shut down any port- and X-forwarded channels going
|
|
* through this connection.
|
|
*/
|
|
if (ssh->channels) {
|
|
while (NULL != (c = index234(ssh->channels, 0))) {
|
|
switch (c->type) {
|
|
case CHAN_X11:
|
|
x11_close(c->u.x11.s);
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
pfd_close(c->u.pfd.s);
|
|
break;
|
|
}
|
|
del234(ssh->channels, c); /* moving next one to index 0 */
|
|
if (ssh->version == 2)
|
|
bufchain_clear(&c->v.v2.outbuffer);
|
|
sfree(c);
|
|
}
|
|
}
|
|
/*
|
|
* Go through port-forwardings, and close any associated
|
|
* listening sockets.
|
|
*/
|
|
if (ssh->portfwds) {
|
|
struct ssh_portfwd *pf;
|
|
while (NULL != (pf = index234(ssh->portfwds, 0))) {
|
|
/* Dispose of any listening socket. */
|
|
if (pf->local)
|
|
pfd_terminate(pf->local);
|
|
del234(ssh->portfwds, pf); /* moving next one to index 0 */
|
|
free_portfwd(pf);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void ssh_log(Plug plug, int type, SockAddr addr, int port,
|
|
const char *error_msg, int error_code)
|
|
{
|
|
Ssh ssh = (Ssh) plug;
|
|
char addrbuf[256], *msg;
|
|
|
|
sk_getaddr(addr, addrbuf, lenof(addrbuf));
|
|
|
|
if (type == 0)
|
|
msg = dupprintf("Connecting to %s port %d", addrbuf, port);
|
|
else
|
|
msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
|
|
|
|
logevent(msg);
|
|
sfree(msg);
|
|
}
|
|
|
|
static int ssh_closing(Plug plug, const char *error_msg, int error_code,
|
|
int calling_back)
|
|
{
|
|
Ssh ssh = (Ssh) plug;
|
|
int need_notify = ssh_do_close(ssh, FALSE);
|
|
|
|
if (!error_msg) {
|
|
if (!ssh->close_expected)
|
|
error_msg = "Server unexpectedly closed network connection";
|
|
else
|
|
error_msg = "Server closed network connection";
|
|
}
|
|
|
|
if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
|
|
ssh->exitcode = 0;
|
|
|
|
if (need_notify)
|
|
notify_remote_exit(ssh->frontend);
|
|
|
|
if (error_msg)
|
|
logevent(error_msg);
|
|
if (!ssh->close_expected || !ssh->clean_exit)
|
|
connection_fatal(ssh->frontend, "%s", error_msg);
|
|
return 0;
|
|
}
|
|
|
|
static int ssh_receive(Plug plug, int urgent, char *data, int len)
|
|
{
|
|
Ssh ssh = (Ssh) plug;
|
|
ssh_gotdata(ssh, (unsigned char *)data, len);
|
|
if (ssh->state == SSH_STATE_CLOSED) {
|
|
ssh_do_close(ssh, TRUE);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void ssh_sent(Plug plug, int bufsize)
|
|
{
|
|
Ssh ssh = (Ssh) plug;
|
|
/*
|
|
* If the send backlog on the SSH socket itself clears, we
|
|
* should unthrottle the whole world if it was throttled.
|
|
*/
|
|
if (bufsize < SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(ssh, 0, bufsize);
|
|
}
|
|
|
|
/*
|
|
* Connect to specified host and port.
|
|
* Returns an error message, or NULL on success.
|
|
* Also places the canonical host name into `realhost'. It must be
|
|
* freed by the caller.
|
|
*/
|
|
static const char *connect_to_host(Ssh ssh, char *host, int port,
|
|
char **realhost, int nodelay, int keepalive)
|
|
{
|
|
static const struct plug_function_table fn_table = {
|
|
ssh_log,
|
|
ssh_closing,
|
|
ssh_receive,
|
|
ssh_sent,
|
|
NULL
|
|
};
|
|
|
|
SockAddr addr;
|
|
const char *err;
|
|
|
|
if (*ssh->cfg.loghost) {
|
|
char *colon;
|
|
|
|
ssh->savedhost = dupstr(ssh->cfg.loghost);
|
|
ssh->savedport = 22; /* default ssh port */
|
|
|
|
/*
|
|
* A colon suffix on savedhost also lets us affect
|
|
* savedport.
|
|
*
|
|
* (FIXME: do something about IPv6 address literals here.)
|
|
*/
|
|
colon = strrchr(ssh->savedhost, ':');
|
|
if (colon) {
|
|
*colon++ = '\0';
|
|
if (*colon)
|
|
ssh->savedport = atoi(colon);
|
|
}
|
|
} else {
|
|
ssh->savedhost = dupstr(host);
|
|
if (port < 0)
|
|
port = 22; /* default ssh port */
|
|
ssh->savedport = port;
|
|
}
|
|
|
|
/*
|
|
* Try to find host.
|
|
*/
|
|
logeventf(ssh, "Looking up host \"%s\"%s", host,
|
|
(ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
|
|
(ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
|
|
addr = name_lookup(host, port, realhost, &ssh->cfg,
|
|
ssh->cfg.addressfamily);
|
|
if ((err = sk_addr_error(addr)) != NULL) {
|
|
sk_addr_free(addr);
|
|
return err;
|
|
}
|
|
ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
|
|
|
|
/*
|
|
* Open socket.
|
|
*/
|
|
ssh->fn = &fn_table;
|
|
ssh->s = new_connection(addr, *realhost, port,
|
|
0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
|
|
if ((err = sk_socket_error(ssh->s)) != NULL) {
|
|
ssh->s = NULL;
|
|
notify_remote_exit(ssh->frontend);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* If the SSH version number's fixed, set it now, and if it's SSH-2,
|
|
* send the version string too.
|
|
*/
|
|
if (ssh->cfg.sshprot == 0)
|
|
ssh->version = 1;
|
|
if (ssh->cfg.sshprot == 3) {
|
|
ssh->version = 2;
|
|
ssh_send_verstring(ssh, NULL);
|
|
}
|
|
|
|
/*
|
|
* loghost, if configured, overrides realhost.
|
|
*/
|
|
if (*ssh->cfg.loghost) {
|
|
sfree(*realhost);
|
|
*realhost = dupstr(ssh->cfg.loghost);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Throttle or unthrottle the SSH connection.
|
|
*/
|
|
static void ssh_throttle_conn(Ssh ssh, int adjust)
|
|
{
|
|
int old_count = ssh->conn_throttle_count;
|
|
ssh->conn_throttle_count += adjust;
|
|
assert(ssh->conn_throttle_count >= 0);
|
|
if (ssh->conn_throttle_count && !old_count) {
|
|
ssh_set_frozen(ssh, 1);
|
|
} else if (!ssh->conn_throttle_count && old_count) {
|
|
ssh_set_frozen(ssh, 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Throttle or unthrottle _all_ local data streams (for when sends
|
|
* on the SSH connection itself back up).
|
|
*/
|
|
static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
|
|
{
|
|
int i;
|
|
struct ssh_channel *c;
|
|
|
|
if (enable == ssh->throttled_all)
|
|
return;
|
|
ssh->throttled_all = enable;
|
|
ssh->overall_bufsize = bufsize;
|
|
if (!ssh->channels)
|
|
return;
|
|
for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
|
|
switch (c->type) {
|
|
case CHAN_MAINSESSION:
|
|
/*
|
|
* This is treated separately, outside the switch.
|
|
*/
|
|
break;
|
|
case CHAN_X11:
|
|
x11_override_throttle(c->u.x11.s, enable);
|
|
break;
|
|
case CHAN_AGENT:
|
|
/* Agent channels require no buffer management. */
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
pfd_override_throttle(c->u.pfd.s, enable);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void ssh_agent_callback(void *sshv, void *reply, int replylen)
|
|
{
|
|
Ssh ssh = (Ssh) sshv;
|
|
|
|
ssh->agent_response = reply;
|
|
ssh->agent_response_len = replylen;
|
|
|
|
if (ssh->version == 1)
|
|
do_ssh1_login(ssh, NULL, -1, NULL);
|
|
else
|
|
do_ssh2_authconn(ssh, NULL, -1, NULL);
|
|
}
|
|
|
|
static void ssh_dialog_callback(void *sshv, int ret)
|
|
{
|
|
Ssh ssh = (Ssh) sshv;
|
|
|
|
ssh->user_response = ret;
|
|
|
|
if (ssh->version == 1)
|
|
do_ssh1_login(ssh, NULL, -1, NULL);
|
|
else
|
|
do_ssh2_transport(ssh, NULL, -1, NULL);
|
|
|
|
/*
|
|
* This may have unfrozen the SSH connection, so do a
|
|
* queued-data run.
|
|
*/
|
|
ssh_process_queued_incoming_data(ssh);
|
|
}
|
|
|
|
static void ssh_agentf_callback(void *cv, void *reply, int replylen)
|
|
{
|
|
struct ssh_channel *c = (struct ssh_channel *)cv;
|
|
Ssh ssh = c->ssh;
|
|
void *sentreply = reply;
|
|
|
|
if (!sentreply) {
|
|
/* Fake SSH_AGENT_FAILURE. */
|
|
sentreply = "\0\0\0\1\5";
|
|
replylen = 5;
|
|
}
|
|
if (ssh->version == 2) {
|
|
ssh2_add_channel_data(c, sentreply, replylen);
|
|
ssh2_try_send(c);
|
|
} else {
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
|
|
PKT_INT, c->remoteid,
|
|
PKT_INT, replylen,
|
|
PKTT_DATA,
|
|
PKT_DATA, sentreply, replylen,
|
|
PKTT_OTHER,
|
|
PKT_END);
|
|
}
|
|
if (reply)
|
|
sfree(reply);
|
|
}
|
|
|
|
/*
|
|
* Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
|
|
* non-NULL, otherwise just close the connection. `client_reason' == NULL
|
|
* => log `wire_reason'.
|
|
*/
|
|
static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
|
|
int code, int clean_exit)
|
|
{
|
|
char *error;
|
|
if (!client_reason)
|
|
client_reason = wire_reason;
|
|
if (client_reason)
|
|
error = dupprintf("Disconnected: %s", client_reason);
|
|
else
|
|
error = dupstr("Disconnected");
|
|
if (wire_reason) {
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
|
|
PKT_END);
|
|
} else if (ssh->version == 2) {
|
|
struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
|
|
ssh2_pkt_adduint32(pktout, code);
|
|
ssh2_pkt_addstring(pktout, wire_reason);
|
|
ssh2_pkt_addstring(pktout, "en"); /* language tag */
|
|
ssh2_pkt_send_noqueue(ssh, pktout);
|
|
}
|
|
}
|
|
ssh->close_expected = TRUE;
|
|
ssh->clean_exit = clean_exit;
|
|
ssh_closing((Plug)ssh, error, 0, 0);
|
|
sfree(error);
|
|
}
|
|
|
|
/*
|
|
* Handle the key exchange and user authentication phases.
|
|
*/
|
|
static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
|
|
struct Packet *pktin)
|
|
{
|
|
int i, j, ret;
|
|
unsigned char cookie[8], *ptr;
|
|
struct RSAKey servkey, hostkey;
|
|
struct MD5Context md5c;
|
|
struct do_ssh1_login_state {
|
|
int len;
|
|
unsigned char *rsabuf, *keystr1, *keystr2;
|
|
unsigned long supported_ciphers_mask, supported_auths_mask;
|
|
int tried_publickey, tried_agent;
|
|
int tis_auth_refused, ccard_auth_refused;
|
|
unsigned char session_id[16];
|
|
int cipher_type;
|
|
char username[100];
|
|
void *publickey_blob;
|
|
int publickey_bloblen;
|
|
char *publickey_comment;
|
|
int publickey_encrypted;
|
|
prompts_t *cur_prompt;
|
|
char c;
|
|
int pwpkt_type;
|
|
unsigned char request[5], *response, *p;
|
|
int responselen;
|
|
int keyi, nkeys;
|
|
int authed;
|
|
struct RSAKey key;
|
|
Bignum challenge;
|
|
char *commentp;
|
|
int commentlen;
|
|
int dlgret;
|
|
};
|
|
crState(do_ssh1_login_state);
|
|
|
|
crBegin(ssh->do_ssh1_login_crstate);
|
|
|
|
if (!pktin)
|
|
crWaitUntil(pktin);
|
|
|
|
if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
|
|
bombout(("Public key packet not received"));
|
|
crStop(0);
|
|
}
|
|
|
|
logevent("Received public keys");
|
|
|
|
ptr = ssh_pkt_getdata(pktin, 8);
|
|
if (!ptr) {
|
|
bombout(("SSH-1 public key packet stopped before random cookie"));
|
|
crStop(0);
|
|
}
|
|
memcpy(cookie, ptr, 8);
|
|
|
|
if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
|
|
!ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
|
|
bombout(("Failed to read SSH-1 public keys from public key packet"));
|
|
crStop(0);
|
|
}
|
|
|
|
/*
|
|
* Log the host key fingerprint.
|
|
*/
|
|
{
|
|
char logmsg[80];
|
|
logevent("Host key fingerprint is:");
|
|
strcpy(logmsg, " ");
|
|
hostkey.comment = NULL;
|
|
rsa_fingerprint(logmsg + strlen(logmsg),
|
|
sizeof(logmsg) - strlen(logmsg), &hostkey);
|
|
logevent(logmsg);
|
|
}
|
|
|
|
ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
|
|
s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
|
|
s->supported_auths_mask = ssh_pkt_getuint32(pktin);
|
|
if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
|
|
s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
|
|
|
|
ssh->v1_local_protoflags =
|
|
ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
|
|
ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, s->keystr2, hostkey.bytes);
|
|
MD5Update(&md5c, s->keystr1, servkey.bytes);
|
|
MD5Update(&md5c, cookie, 8);
|
|
MD5Final(s->session_id, &md5c);
|
|
|
|
for (i = 0; i < 32; i++)
|
|
ssh->session_key[i] = random_byte();
|
|
|
|
/*
|
|
* Verify that the `bits' and `bytes' parameters match.
|
|
*/
|
|
if (hostkey.bits > hostkey.bytes * 8 ||
|
|
servkey.bits > servkey.bytes * 8) {
|
|
bombout(("SSH-1 public keys were badly formatted"));
|
|
crStop(0);
|
|
}
|
|
|
|
s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
|
|
|
|
s->rsabuf = snewn(s->len, unsigned char);
|
|
|
|
/*
|
|
* Verify the host key.
|
|
*/
|
|
{
|
|
/*
|
|
* First format the key into a string.
|
|
*/
|
|
int len = rsastr_len(&hostkey);
|
|
char fingerprint[100];
|
|
char *keystr = snewn(len, char);
|
|
rsastr_fmt(keystr, &hostkey);
|
|
rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
|
|
|
|
ssh_set_frozen(ssh, 1);
|
|
s->dlgret = verify_ssh_host_key(ssh->frontend,
|
|
ssh->savedhost, ssh->savedport,
|
|
"rsa", keystr, fingerprint,
|
|
ssh_dialog_callback, ssh);
|
|
sfree(keystr);
|
|
if (s->dlgret < 0) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while waiting"
|
|
" for user host key response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
s->dlgret = ssh->user_response;
|
|
}
|
|
ssh_set_frozen(ssh, 0);
|
|
|
|
if (s->dlgret == 0) {
|
|
ssh_disconnect(ssh, "User aborted at host key verification",
|
|
NULL, 0, TRUE);
|
|
crStop(0);
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < 32; i++) {
|
|
s->rsabuf[i] = ssh->session_key[i];
|
|
if (i < 16)
|
|
s->rsabuf[i] ^= s->session_id[i];
|
|
}
|
|
|
|
if (hostkey.bytes > servkey.bytes) {
|
|
ret = rsaencrypt(s->rsabuf, 32, &servkey);
|
|
if (ret)
|
|
ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
|
|
} else {
|
|
ret = rsaencrypt(s->rsabuf, 32, &hostkey);
|
|
if (ret)
|
|
ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
|
|
}
|
|
if (!ret) {
|
|
bombout(("SSH-1 public key encryptions failed due to bad formatting"));
|
|
crStop(0);
|
|
}
|
|
|
|
logevent("Encrypted session key");
|
|
|
|
{
|
|
int cipher_chosen = 0, warn = 0;
|
|
char *cipher_string = NULL;
|
|
int i;
|
|
for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
|
|
int next_cipher = ssh->cfg.ssh_cipherlist[i];
|
|
if (next_cipher == CIPHER_WARN) {
|
|
/* If/when we choose a cipher, warn about it */
|
|
warn = 1;
|
|
} else if (next_cipher == CIPHER_AES) {
|
|
/* XXX Probably don't need to mention this. */
|
|
logevent("AES not supported in SSH-1, skipping");
|
|
} else {
|
|
switch (next_cipher) {
|
|
case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
|
|
cipher_string = "3DES"; break;
|
|
case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
|
|
cipher_string = "Blowfish"; break;
|
|
case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
|
|
cipher_string = "single-DES"; break;
|
|
}
|
|
if (s->supported_ciphers_mask & (1 << s->cipher_type))
|
|
cipher_chosen = 1;
|
|
}
|
|
}
|
|
if (!cipher_chosen) {
|
|
if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
|
|
bombout(("Server violates SSH-1 protocol by not "
|
|
"supporting 3DES encryption"));
|
|
else
|
|
/* shouldn't happen */
|
|
bombout(("No supported ciphers found"));
|
|
crStop(0);
|
|
}
|
|
|
|
/* Warn about chosen cipher if necessary. */
|
|
if (warn) {
|
|
ssh_set_frozen(ssh, 1);
|
|
s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
|
|
ssh_dialog_callback, ssh);
|
|
if (s->dlgret < 0) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while waiting"
|
|
" for user response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
s->dlgret = ssh->user_response;
|
|
}
|
|
ssh_set_frozen(ssh, 0);
|
|
if (s->dlgret == 0) {
|
|
ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
|
|
0, TRUE);
|
|
crStop(0);
|
|
}
|
|
}
|
|
}
|
|
|
|
switch (s->cipher_type) {
|
|
case SSH_CIPHER_3DES:
|
|
logevent("Using 3DES encryption");
|
|
break;
|
|
case SSH_CIPHER_DES:
|
|
logevent("Using single-DES encryption");
|
|
break;
|
|
case SSH_CIPHER_BLOWFISH:
|
|
logevent("Using Blowfish encryption");
|
|
break;
|
|
}
|
|
|
|
send_packet(ssh, SSH1_CMSG_SESSION_KEY,
|
|
PKT_CHAR, s->cipher_type,
|
|
PKT_DATA, cookie, 8,
|
|
PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
|
|
PKT_DATA, s->rsabuf, s->len,
|
|
PKT_INT, ssh->v1_local_protoflags, PKT_END);
|
|
|
|
logevent("Trying to enable encryption...");
|
|
|
|
sfree(s->rsabuf);
|
|
|
|
ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
|
|
s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
|
|
&ssh_3des);
|
|
ssh->v1_cipher_ctx = ssh->cipher->make_context();
|
|
ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
|
|
logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
|
|
|
|
ssh->crcda_ctx = crcda_make_context();
|
|
logevent("Installing CRC compensation attack detector");
|
|
|
|
if (servkey.modulus) {
|
|
sfree(servkey.modulus);
|
|
servkey.modulus = NULL;
|
|
}
|
|
if (servkey.exponent) {
|
|
sfree(servkey.exponent);
|
|
servkey.exponent = NULL;
|
|
}
|
|
if (hostkey.modulus) {
|
|
sfree(hostkey.modulus);
|
|
hostkey.modulus = NULL;
|
|
}
|
|
if (hostkey.exponent) {
|
|
sfree(hostkey.exponent);
|
|
hostkey.exponent = NULL;
|
|
}
|
|
crWaitUntil(pktin);
|
|
|
|
if (pktin->type != SSH1_SMSG_SUCCESS) {
|
|
bombout(("Encryption not successfully enabled"));
|
|
crStop(0);
|
|
}
|
|
|
|
logevent("Successfully started encryption");
|
|
|
|
fflush(stdout); /* FIXME eh? */
|
|
{
|
|
if (!get_remote_username(&ssh->cfg, s->username,
|
|
sizeof(s->username))) {
|
|
int ret; /* need not be kept over crReturn */
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("SSH login name");
|
|
add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
|
|
lenof(s->username));
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntil(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* Failed to get a username. Terminate.
|
|
*/
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
|
|
crStop(0);
|
|
}
|
|
memcpy(s->username, s->cur_prompt->prompts[0]->result,
|
|
lenof(s->username));
|
|
free_prompts(s->cur_prompt);
|
|
}
|
|
|
|
send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
|
|
{
|
|
char *userlog = dupprintf("Sent username \"%s\"", s->username);
|
|
logevent(userlog);
|
|
if (flags & FLAG_INTERACTIVE &&
|
|
(!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
|
|
c_write_str(ssh, userlog);
|
|
c_write_str(ssh, "\r\n");
|
|
}
|
|
sfree(userlog);
|
|
}
|
|
}
|
|
|
|
crWaitUntil(pktin);
|
|
|
|
if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
|
|
/* We must not attempt PK auth. Pretend we've already tried it. */
|
|
s->tried_publickey = s->tried_agent = 1;
|
|
} else {
|
|
s->tried_publickey = s->tried_agent = 0;
|
|
}
|
|
s->tis_auth_refused = s->ccard_auth_refused = 0;
|
|
/*
|
|
* Load the public half of any configured keyfile for later use.
|
|
*/
|
|
if (!filename_is_null(ssh->cfg.keyfile)) {
|
|
int keytype;
|
|
logeventf(ssh, "Reading private key file \"%.150s\"",
|
|
filename_to_str(&ssh->cfg.keyfile));
|
|
keytype = key_type(&ssh->cfg.keyfile);
|
|
if (keytype == SSH_KEYTYPE_SSH1) {
|
|
const char *error;
|
|
if (rsakey_pubblob(&ssh->cfg.keyfile,
|
|
&s->publickey_blob, &s->publickey_bloblen,
|
|
&s->publickey_comment, &error)) {
|
|
s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
|
|
NULL);
|
|
} else {
|
|
char *msgbuf;
|
|
logeventf(ssh, "Unable to load private key (%s)", error);
|
|
msgbuf = dupprintf("Unable to load private key file "
|
|
"\"%.150s\" (%s)\r\n",
|
|
filename_to_str(&ssh->cfg.keyfile),
|
|
error);
|
|
c_write_str(ssh, msgbuf);
|
|
sfree(msgbuf);
|
|
s->publickey_blob = NULL;
|
|
}
|
|
} else {
|
|
char *msgbuf;
|
|
logeventf(ssh, "Unable to use this key file (%s)",
|
|
key_type_to_str(keytype));
|
|
msgbuf = dupprintf("Unable to use key file \"%.150s\""
|
|
" (%s)\r\n",
|
|
filename_to_str(&ssh->cfg.keyfile),
|
|
key_type_to_str(keytype));
|
|
c_write_str(ssh, msgbuf);
|
|
sfree(msgbuf);
|
|
s->publickey_blob = NULL;
|
|
}
|
|
} else
|
|
s->publickey_blob = NULL;
|
|
|
|
while (pktin->type == SSH1_SMSG_FAILURE) {
|
|
s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
|
|
|
|
if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
|
|
/*
|
|
* Attempt RSA authentication using Pageant.
|
|
*/
|
|
void *r;
|
|
|
|
s->authed = FALSE;
|
|
s->tried_agent = 1;
|
|
logevent("Pageant is running. Requesting keys.");
|
|
|
|
/* Request the keys held by the agent. */
|
|
PUT_32BIT(s->request, 1);
|
|
s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
|
|
if (!agent_query(s->request, 5, &r, &s->responselen,
|
|
ssh_agent_callback, ssh)) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while waiting"
|
|
" for agent response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
r = ssh->agent_response;
|
|
s->responselen = ssh->agent_response_len;
|
|
}
|
|
s->response = (unsigned char *) r;
|
|
if (s->response && s->responselen >= 5 &&
|
|
s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
|
|
s->p = s->response + 5;
|
|
s->nkeys = GET_32BIT(s->p);
|
|
s->p += 4;
|
|
logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
|
|
for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
|
|
unsigned char *pkblob = s->p;
|
|
s->p += 4;
|
|
{
|
|
int n, ok = FALSE;
|
|
do { /* do while (0) to make breaking easy */
|
|
n = ssh1_read_bignum
|
|
(s->p, s->responselen-(s->p-s->response),
|
|
&s->key.exponent);
|
|
if (n < 0)
|
|
break;
|
|
s->p += n;
|
|
n = ssh1_read_bignum
|
|
(s->p, s->responselen-(s->p-s->response),
|
|
&s->key.modulus);
|
|
if (n < 0)
|
|
break;
|
|
s->p += n;
|
|
if (s->responselen - (s->p-s->response) < 4)
|
|
break;
|
|
s->commentlen = GET_32BIT(s->p);
|
|
s->p += 4;
|
|
if (s->responselen - (s->p-s->response) <
|
|
s->commentlen)
|
|
break;
|
|
s->commentp = (char *)s->p;
|
|
s->p += s->commentlen;
|
|
ok = TRUE;
|
|
} while (0);
|
|
if (!ok) {
|
|
logevent("Pageant key list packet was truncated");
|
|
break;
|
|
}
|
|
}
|
|
if (s->publickey_blob) {
|
|
if (!memcmp(pkblob, s->publickey_blob,
|
|
s->publickey_bloblen)) {
|
|
logeventf(ssh, "Pageant key #%d matches "
|
|
"configured key file", s->keyi);
|
|
s->tried_publickey = 1;
|
|
} else
|
|
/* Skip non-configured key */
|
|
continue;
|
|
}
|
|
logeventf(ssh, "Trying Pageant key #%d", s->keyi);
|
|
send_packet(ssh, SSH1_CMSG_AUTH_RSA,
|
|
PKT_BIGNUM, s->key.modulus, PKT_END);
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
|
|
logevent("Key refused");
|
|
continue;
|
|
}
|
|
logevent("Received RSA challenge");
|
|
if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
|
|
bombout(("Server's RSA challenge was badly formatted"));
|
|
crStop(0);
|
|
}
|
|
|
|
{
|
|
char *agentreq, *q, *ret;
|
|
void *vret;
|
|
int len, retlen;
|
|
len = 1 + 4; /* message type, bit count */
|
|
len += ssh1_bignum_length(s->key.exponent);
|
|
len += ssh1_bignum_length(s->key.modulus);
|
|
len += ssh1_bignum_length(s->challenge);
|
|
len += 16; /* session id */
|
|
len += 4; /* response format */
|
|
agentreq = snewn(4 + len, char);
|
|
PUT_32BIT(agentreq, len);
|
|
q = agentreq + 4;
|
|
*q++ = SSH1_AGENTC_RSA_CHALLENGE;
|
|
PUT_32BIT(q, bignum_bitcount(s->key.modulus));
|
|
q += 4;
|
|
q += ssh1_write_bignum(q, s->key.exponent);
|
|
q += ssh1_write_bignum(q, s->key.modulus);
|
|
q += ssh1_write_bignum(q, s->challenge);
|
|
memcpy(q, s->session_id, 16);
|
|
q += 16;
|
|
PUT_32BIT(q, 1); /* response format */
|
|
if (!agent_query(agentreq, len + 4, &vret, &retlen,
|
|
ssh_agent_callback, ssh)) {
|
|
sfree(agentreq);
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server"
|
|
" while waiting for agent"
|
|
" response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
vret = ssh->agent_response;
|
|
retlen = ssh->agent_response_len;
|
|
} else
|
|
sfree(agentreq);
|
|
ret = vret;
|
|
if (ret) {
|
|
if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
|
|
logevent("Sending Pageant's response");
|
|
send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
|
|
PKT_DATA, ret + 5, 16,
|
|
PKT_END);
|
|
sfree(ret);
|
|
crWaitUntil(pktin);
|
|
if (pktin->type == SSH1_SMSG_SUCCESS) {
|
|
logevent
|
|
("Pageant's response accepted");
|
|
if (flags & FLAG_VERBOSE) {
|
|
c_write_str(ssh, "Authenticated using"
|
|
" RSA key \"");
|
|
c_write(ssh, s->commentp,
|
|
s->commentlen);
|
|
c_write_str(ssh, "\" from agent\r\n");
|
|
}
|
|
s->authed = TRUE;
|
|
} else
|
|
logevent
|
|
("Pageant's response not accepted");
|
|
} else {
|
|
logevent
|
|
("Pageant failed to answer challenge");
|
|
sfree(ret);
|
|
}
|
|
} else {
|
|
logevent("No reply received from Pageant");
|
|
}
|
|
}
|
|
freebn(s->key.exponent);
|
|
freebn(s->key.modulus);
|
|
freebn(s->challenge);
|
|
if (s->authed)
|
|
break;
|
|
}
|
|
sfree(s->response);
|
|
if (s->publickey_blob && !s->tried_publickey)
|
|
logevent("Configured key file not in Pageant");
|
|
}
|
|
if (s->authed)
|
|
break;
|
|
}
|
|
if (s->publickey_blob && !s->tried_publickey) {
|
|
/*
|
|
* Try public key authentication with the specified
|
|
* key file.
|
|
*/
|
|
int got_passphrase; /* need not be kept over crReturn */
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str(ssh, "Trying public key authentication.\r\n");
|
|
logeventf(ssh, "Trying public key \"%s\"",
|
|
filename_to_str(&ssh->cfg.keyfile));
|
|
s->tried_publickey = 1;
|
|
got_passphrase = FALSE;
|
|
while (!got_passphrase) {
|
|
/*
|
|
* Get a passphrase, if necessary.
|
|
*/
|
|
char *passphrase = NULL; /* only written after crReturn */
|
|
const char *error;
|
|
if (!s->publickey_encrypted) {
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str(ssh, "No passphrase required.\r\n");
|
|
passphrase = NULL;
|
|
} else {
|
|
int ret; /* need not be kept over crReturn */
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = FALSE;
|
|
s->cur_prompt->name = dupstr("SSH key passphrase");
|
|
add_prompt(s->cur_prompt,
|
|
dupprintf("Passphrase for key \"%.100s\": ",
|
|
s->publickey_comment),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntil(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/* Failed to get a passphrase. Terminate. */
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, NULL, "Unable to authenticate",
|
|
0, TRUE);
|
|
crStop(0);
|
|
}
|
|
passphrase = dupstr(s->cur_prompt->prompts[0]->result);
|
|
free_prompts(s->cur_prompt);
|
|
}
|
|
/*
|
|
* Try decrypting key with passphrase.
|
|
*/
|
|
ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
|
|
&error);
|
|
if (passphrase) {
|
|
memset(passphrase, 0, strlen(passphrase));
|
|
sfree(passphrase);
|
|
}
|
|
if (ret == 1) {
|
|
/* Correct passphrase. */
|
|
got_passphrase = TRUE;
|
|
} else if (ret == 0) {
|
|
c_write_str(ssh, "Couldn't load private key from ");
|
|
c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
|
|
c_write_str(ssh, " (");
|
|
c_write_str(ssh, error);
|
|
c_write_str(ssh, ").\r\n");
|
|
got_passphrase = FALSE;
|
|
break; /* go and try something else */
|
|
} else if (ret == -1) {
|
|
c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
|
|
got_passphrase = FALSE;
|
|
/* and try again */
|
|
} else {
|
|
assert(0 && "unexpected return from loadrsakey()");
|
|
got_passphrase = FALSE; /* placate optimisers */
|
|
}
|
|
}
|
|
|
|
if (got_passphrase) {
|
|
|
|
/*
|
|
* Send a public key attempt.
|
|
*/
|
|
send_packet(ssh, SSH1_CMSG_AUTH_RSA,
|
|
PKT_BIGNUM, s->key.modulus, PKT_END);
|
|
|
|
crWaitUntil(pktin);
|
|
if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
c_write_str(ssh, "Server refused our public key.\r\n");
|
|
continue; /* go and try something else */
|
|
}
|
|
if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
|
|
bombout(("Bizarre response to offer of public key"));
|
|
crStop(0);
|
|
}
|
|
|
|
{
|
|
int i;
|
|
unsigned char buffer[32];
|
|
Bignum challenge, response;
|
|
|
|
if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
|
|
bombout(("Server's RSA challenge was badly formatted"));
|
|
crStop(0);
|
|
}
|
|
response = rsadecrypt(challenge, &s->key);
|
|
freebn(s->key.private_exponent);/* burn the evidence */
|
|
|
|
for (i = 0; i < 32; i++) {
|
|
buffer[i] = bignum_byte(response, 31 - i);
|
|
}
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, buffer, 32);
|
|
MD5Update(&md5c, s->session_id, 16);
|
|
MD5Final(buffer, &md5c);
|
|
|
|
send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
|
|
PKT_DATA, buffer, 16, PKT_END);
|
|
|
|
freebn(challenge);
|
|
freebn(response);
|
|
}
|
|
|
|
crWaitUntil(pktin);
|
|
if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str(ssh, "Failed to authenticate with"
|
|
" our public key.\r\n");
|
|
continue; /* go and try something else */
|
|
} else if (pktin->type != SSH1_SMSG_SUCCESS) {
|
|
bombout(("Bizarre response to RSA authentication response"));
|
|
crStop(0);
|
|
}
|
|
|
|
break; /* we're through! */
|
|
}
|
|
|
|
}
|
|
|
|
/*
|
|
* Otherwise, try various forms of password-like authentication.
|
|
*/
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
|
|
if (ssh->cfg.try_tis_auth &&
|
|
(s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
|
|
!s->tis_auth_refused) {
|
|
s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
|
|
logevent("Requested TIS authentication");
|
|
send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
|
|
logevent("TIS authentication declined");
|
|
if (flags & FLAG_INTERACTIVE)
|
|
c_write_str(ssh, "TIS authentication refused.\r\n");
|
|
s->tis_auth_refused = 1;
|
|
continue;
|
|
} else {
|
|
char *challenge;
|
|
int challengelen;
|
|
char *instr_suf, *prompt;
|
|
|
|
ssh_pkt_getstring(pktin, &challenge, &challengelen);
|
|
if (!challenge) {
|
|
bombout(("TIS challenge packet was badly formed"));
|
|
crStop(0);
|
|
}
|
|
logevent("Received TIS challenge");
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("SSH TIS authentication");
|
|
/* Prompt heuristic comes from OpenSSH */
|
|
if (memchr(challenge, '\n', challengelen)) {
|
|
instr_suf = dupstr("");
|
|
prompt = dupprintf("%.*s", challengelen, challenge);
|
|
} else {
|
|
instr_suf = dupprintf("%.*s", challengelen, challenge);
|
|
prompt = dupstr("Response: ");
|
|
}
|
|
s->cur_prompt->instruction =
|
|
dupprintf("Using TIS authentication.%s%s",
|
|
(*instr_suf) ? "\n" : "",
|
|
instr_suf);
|
|
s->cur_prompt->instr_reqd = TRUE;
|
|
add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
|
|
sfree(instr_suf);
|
|
}
|
|
}
|
|
if (ssh->cfg.try_tis_auth &&
|
|
(s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
|
|
!s->ccard_auth_refused) {
|
|
s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
|
|
logevent("Requested CryptoCard authentication");
|
|
send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
|
|
logevent("CryptoCard authentication declined");
|
|
c_write_str(ssh, "CryptoCard authentication refused.\r\n");
|
|
s->ccard_auth_refused = 1;
|
|
continue;
|
|
} else {
|
|
char *challenge;
|
|
int challengelen;
|
|
char *instr_suf, *prompt;
|
|
|
|
ssh_pkt_getstring(pktin, &challenge, &challengelen);
|
|
if (!challenge) {
|
|
bombout(("CryptoCard challenge packet was badly formed"));
|
|
crStop(0);
|
|
}
|
|
logevent("Received CryptoCard challenge");
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
|
|
s->cur_prompt->name_reqd = FALSE;
|
|
/* Prompt heuristic comes from OpenSSH */
|
|
if (memchr(challenge, '\n', challengelen)) {
|
|
instr_suf = dupstr("");
|
|
prompt = dupprintf("%.*s", challengelen, challenge);
|
|
} else {
|
|
instr_suf = dupprintf("%.*s", challengelen, challenge);
|
|
prompt = dupstr("Response: ");
|
|
}
|
|
s->cur_prompt->instruction =
|
|
dupprintf("Using CryptoCard authentication.%s%s",
|
|
(*instr_suf) ? "\n" : "",
|
|
instr_suf);
|
|
s->cur_prompt->instr_reqd = TRUE;
|
|
add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
|
|
sfree(instr_suf);
|
|
}
|
|
}
|
|
if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
|
|
if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
|
|
bombout(("No supported authentication methods available"));
|
|
crStop(0);
|
|
}
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("SSH password");
|
|
add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
|
|
s->username, ssh->savedhost),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
}
|
|
|
|
/*
|
|
* Show password prompt, having first obtained it via a TIS
|
|
* or CryptoCard exchange if we're doing TIS or CryptoCard
|
|
* authentication.
|
|
*/
|
|
{
|
|
int ret; /* need not be kept over crReturn */
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntil(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* Failed to get a password (for example
|
|
* because one was supplied on the command line
|
|
* which has already failed to work). Terminate.
|
|
*/
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
|
|
crStop(0);
|
|
}
|
|
}
|
|
|
|
if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
|
|
/*
|
|
* Defence against traffic analysis: we send a
|
|
* whole bunch of packets containing strings of
|
|
* different lengths. One of these strings is the
|
|
* password, in a SSH1_CMSG_AUTH_PASSWORD packet.
|
|
* The others are all random data in
|
|
* SSH1_MSG_IGNORE packets. This way a passive
|
|
* listener can't tell which is the password, and
|
|
* hence can't deduce the password length.
|
|
*
|
|
* Anybody with a password length greater than 16
|
|
* bytes is going to have enough entropy in their
|
|
* password that a listener won't find it _that_
|
|
* much help to know how long it is. So what we'll
|
|
* do is:
|
|
*
|
|
* - if password length < 16, we send 15 packets
|
|
* containing string lengths 1 through 15
|
|
*
|
|
* - otherwise, we let N be the nearest multiple
|
|
* of 8 below the password length, and send 8
|
|
* packets containing string lengths N through
|
|
* N+7. This won't obscure the order of
|
|
* magnitude of the password length, but it will
|
|
* introduce a bit of extra uncertainty.
|
|
*
|
|
* A few servers can't deal with SSH1_MSG_IGNORE, at
|
|
* least in this context. For these servers, we need
|
|
* an alternative defence. We make use of the fact
|
|
* that the password is interpreted as a C string:
|
|
* so we can append a NUL, then some random data.
|
|
*
|
|
* A few servers can deal with neither SSH1_MSG_IGNORE
|
|
* here _nor_ a padded password string.
|
|
* For these servers we are left with no defences
|
|
* against password length sniffing.
|
|
*/
|
|
if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
|
|
!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
|
|
/*
|
|
* The server can deal with SSH1_MSG_IGNORE, so
|
|
* we can use the primary defence.
|
|
*/
|
|
int bottom, top, pwlen, i;
|
|
char *randomstr;
|
|
|
|
pwlen = strlen(s->cur_prompt->prompts[0]->result);
|
|
if (pwlen < 16) {
|
|
bottom = 0; /* zero length passwords are OK! :-) */
|
|
top = 15;
|
|
} else {
|
|
bottom = pwlen & ~7;
|
|
top = bottom + 7;
|
|
}
|
|
|
|
assert(pwlen >= bottom && pwlen <= top);
|
|
|
|
randomstr = snewn(top + 1, char);
|
|
|
|
for (i = bottom; i <= top; i++) {
|
|
if (i == pwlen) {
|
|
defer_packet(ssh, s->pwpkt_type,
|
|
PKTT_PASSWORD, PKT_STR,
|
|
s->cur_prompt->prompts[0]->result,
|
|
PKTT_OTHER, PKT_END);
|
|
} else {
|
|
for (j = 0; j < i; j++) {
|
|
do {
|
|
randomstr[j] = random_byte();
|
|
} while (randomstr[j] == '\0');
|
|
}
|
|
randomstr[i] = '\0';
|
|
defer_packet(ssh, SSH1_MSG_IGNORE,
|
|
PKT_STR, randomstr, PKT_END);
|
|
}
|
|
}
|
|
logevent("Sending password with camouflage packets");
|
|
ssh_pkt_defersend(ssh);
|
|
sfree(randomstr);
|
|
}
|
|
else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
|
|
/*
|
|
* The server can't deal with SSH1_MSG_IGNORE
|
|
* but can deal with padded passwords, so we
|
|
* can use the secondary defence.
|
|
*/
|
|
char string[64];
|
|
char *ss;
|
|
int len;
|
|
|
|
len = strlen(s->cur_prompt->prompts[0]->result);
|
|
if (len < sizeof(string)) {
|
|
ss = string;
|
|
strcpy(string, s->cur_prompt->prompts[0]->result);
|
|
len++; /* cover the zero byte */
|
|
while (len < sizeof(string)) {
|
|
string[len++] = (char) random_byte();
|
|
}
|
|
} else {
|
|
ss = s->cur_prompt->prompts[0]->result;
|
|
}
|
|
logevent("Sending length-padded password");
|
|
send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
|
|
PKT_INT, len, PKT_DATA, ss, len,
|
|
PKTT_OTHER, PKT_END);
|
|
} else {
|
|
/*
|
|
* The server is believed unable to cope with
|
|
* any of our password camouflage methods.
|
|
*/
|
|
int len;
|
|
len = strlen(s->cur_prompt->prompts[0]->result);
|
|
logevent("Sending unpadded password");
|
|
send_packet(ssh, s->pwpkt_type,
|
|
PKTT_PASSWORD, PKT_INT, len,
|
|
PKT_DATA, s->cur_prompt->prompts[0]->result, len,
|
|
PKTT_OTHER, PKT_END);
|
|
}
|
|
} else {
|
|
send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
|
|
PKT_STR, s->cur_prompt->prompts[0]->result,
|
|
PKTT_OTHER, PKT_END);
|
|
}
|
|
logevent("Sent password");
|
|
free_prompts(s->cur_prompt);
|
|
crWaitUntil(pktin);
|
|
if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str(ssh, "Access denied\r\n");
|
|
logevent("Authentication refused");
|
|
} else if (pktin->type != SSH1_SMSG_SUCCESS) {
|
|
bombout(("Strange packet received, type %d", pktin->type));
|
|
crStop(0);
|
|
}
|
|
}
|
|
|
|
/* Clear up */
|
|
if (s->publickey_blob) {
|
|
sfree(s->publickey_blob);
|
|
sfree(s->publickey_comment);
|
|
}
|
|
|
|
logevent("Authentication successful");
|
|
|
|
crFinish(1);
|
|
}
|
|
|
|
void sshfwd_close(struct ssh_channel *c)
|
|
{
|
|
Ssh ssh = c->ssh;
|
|
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return;
|
|
|
|
if (c && !c->closes) {
|
|
/*
|
|
* If halfopen is true, we have sent
|
|
* CHANNEL_OPEN for this channel, but it hasn't even been
|
|
* acknowledged by the server. So we must set a close flag
|
|
* on it now, and then when the server acks the channel
|
|
* open, we can close it then.
|
|
*/
|
|
if (!c->halfopen) {
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
|
|
PKT_END);
|
|
} else {
|
|
struct Packet *pktout;
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
c->closes = 1; /* sent MSG_CLOSE */
|
|
if (c->type == CHAN_X11) {
|
|
c->u.x11.s = NULL;
|
|
logevent("Forwarded X11 connection terminated");
|
|
} else if (c->type == CHAN_SOCKDATA ||
|
|
c->type == CHAN_SOCKDATA_DORMANT) {
|
|
c->u.pfd.s = NULL;
|
|
logevent("Forwarded port closed");
|
|
}
|
|
}
|
|
}
|
|
|
|
int sshfwd_write(struct ssh_channel *c, char *buf, int len)
|
|
{
|
|
Ssh ssh = c->ssh;
|
|
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return 0;
|
|
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
|
|
PKT_INT, c->remoteid,
|
|
PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
|
|
PKTT_OTHER, PKT_END);
|
|
/*
|
|
* In SSH-1 we can return 0 here - implying that forwarded
|
|
* connections are never individually throttled - because
|
|
* the only circumstance that can cause throttling will be
|
|
* the whole SSH connection backing up, in which case
|
|
* _everything_ will be throttled as a whole.
|
|
*/
|
|
return 0;
|
|
} else {
|
|
ssh2_add_channel_data(c, buf, len);
|
|
return ssh2_try_send(c);
|
|
}
|
|
}
|
|
|
|
void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
|
|
{
|
|
Ssh ssh = c->ssh;
|
|
int buflimit;
|
|
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return;
|
|
|
|
if (ssh->version == 1) {
|
|
buflimit = SSH1_BUFFER_LIMIT;
|
|
} else {
|
|
buflimit = c->v.v2.locmaxwin;
|
|
ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
|
|
}
|
|
if (c->throttling_conn && bufsize <= buflimit) {
|
|
c->throttling_conn = 0;
|
|
ssh_throttle_conn(ssh, -1);
|
|
}
|
|
}
|
|
|
|
static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
struct queued_handler *qh = ssh->qhead;
|
|
|
|
assert(qh != NULL);
|
|
|
|
assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
|
|
|
|
if (qh->msg1 > 0) {
|
|
assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
|
|
ssh->packet_dispatch[qh->msg1] = NULL;
|
|
}
|
|
if (qh->msg2 > 0) {
|
|
assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
|
|
ssh->packet_dispatch[qh->msg2] = NULL;
|
|
}
|
|
|
|
if (qh->next) {
|
|
ssh->qhead = qh->next;
|
|
|
|
if (ssh->qhead->msg1 > 0) {
|
|
assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
|
|
ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
|
|
}
|
|
if (ssh->qhead->msg2 > 0) {
|
|
assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
|
|
ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
|
|
}
|
|
} else {
|
|
ssh->qhead = ssh->qtail = NULL;
|
|
ssh->packet_dispatch[pktin->type] = NULL;
|
|
}
|
|
|
|
qh->handler(ssh, pktin, qh->ctx);
|
|
|
|
sfree(qh);
|
|
}
|
|
|
|
static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
|
|
chandler_fn_t handler, void *ctx)
|
|
{
|
|
struct queued_handler *qh;
|
|
|
|
qh = snew(struct queued_handler);
|
|
qh->msg1 = msg1;
|
|
qh->msg2 = msg2;
|
|
qh->handler = handler;
|
|
qh->ctx = ctx;
|
|
qh->next = NULL;
|
|
|
|
if (ssh->qtail == NULL) {
|
|
ssh->qhead = qh;
|
|
|
|
if (qh->msg1 > 0) {
|
|
assert(ssh->packet_dispatch[qh->msg1] == NULL);
|
|
ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
|
|
}
|
|
if (qh->msg2 > 0) {
|
|
assert(ssh->packet_dispatch[qh->msg2] == NULL);
|
|
ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
|
|
}
|
|
} else {
|
|
ssh->qtail->next = qh;
|
|
}
|
|
ssh->qtail = qh;
|
|
}
|
|
|
|
static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
|
|
{
|
|
struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
|
|
|
|
if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
|
|
SSH2_MSG_REQUEST_SUCCESS)) {
|
|
logeventf(ssh, "Remote port forwarding from %s enabled",
|
|
pf->sportdesc);
|
|
} else {
|
|
logeventf(ssh, "Remote port forwarding from %s refused",
|
|
pf->sportdesc);
|
|
|
|
rpf = del234(ssh->rportfwds, pf);
|
|
assert(rpf == pf);
|
|
free_rportfwd(pf);
|
|
}
|
|
}
|
|
|
|
static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
|
|
{
|
|
const char *portfwd_strptr = cfg->portfwd;
|
|
struct ssh_portfwd *epf;
|
|
int i;
|
|
|
|
if (!ssh->portfwds) {
|
|
ssh->portfwds = newtree234(ssh_portcmp);
|
|
} else {
|
|
/*
|
|
* Go through the existing port forwardings and tag them
|
|
* with status==DESTROY. Any that we want to keep will be
|
|
* re-enabled (status==KEEP) as we go through the
|
|
* configuration and find out which bits are the same as
|
|
* they were before.
|
|
*/
|
|
struct ssh_portfwd *epf;
|
|
int i;
|
|
for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
|
|
epf->status = DESTROY;
|
|
}
|
|
|
|
while (*portfwd_strptr) {
|
|
char address_family, type;
|
|
int sport,dport,sserv,dserv;
|
|
char sports[256], dports[256], saddr[256], host[256];
|
|
int n;
|
|
|
|
address_family = 'A';
|
|
type = 'L';
|
|
if (*portfwd_strptr == 'A' ||
|
|
*portfwd_strptr == '4' ||
|
|
*portfwd_strptr == '6')
|
|
address_family = *portfwd_strptr++;
|
|
if (*portfwd_strptr == 'L' ||
|
|
*portfwd_strptr == 'R' ||
|
|
*portfwd_strptr == 'D')
|
|
type = *portfwd_strptr++;
|
|
|
|
saddr[0] = '\0';
|
|
|
|
n = 0;
|
|
while (*portfwd_strptr && *portfwd_strptr != '\t') {
|
|
if (*portfwd_strptr == ':') {
|
|
/*
|
|
* We've seen a colon in the middle of the
|
|
* source port number. This means that
|
|
* everything we've seen until now is the
|
|
* source _address_, so we'll move it into
|
|
* saddr and start sports from the beginning
|
|
* again.
|
|
*/
|
|
portfwd_strptr++;
|
|
sports[n] = '\0';
|
|
if (ssh->version == 1 && type == 'R') {
|
|
logeventf(ssh, "SSH-1 cannot handle remote source address "
|
|
"spec \"%s\"; ignoring", sports);
|
|
} else
|
|
strcpy(saddr, sports);
|
|
n = 0;
|
|
}
|
|
if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
|
|
}
|
|
sports[n] = 0;
|
|
if (type != 'D') {
|
|
if (*portfwd_strptr == '\t')
|
|
portfwd_strptr++;
|
|
n = 0;
|
|
while (*portfwd_strptr && *portfwd_strptr != ':') {
|
|
if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
|
|
}
|
|
host[n] = 0;
|
|
if (*portfwd_strptr == ':')
|
|
portfwd_strptr++;
|
|
n = 0;
|
|
while (*portfwd_strptr) {
|
|
if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
|
|
}
|
|
dports[n] = 0;
|
|
portfwd_strptr++;
|
|
dport = atoi(dports);
|
|
dserv = 0;
|
|
if (dport == 0) {
|
|
dserv = 1;
|
|
dport = net_service_lookup(dports);
|
|
if (!dport) {
|
|
logeventf(ssh, "Service lookup failed for destination"
|
|
" port \"%s\"", dports);
|
|
}
|
|
}
|
|
} else {
|
|
while (*portfwd_strptr) portfwd_strptr++;
|
|
host[0] = 0;
|
|
dports[0] = 0;
|
|
dport = dserv = -1;
|
|
portfwd_strptr++; /* eat the NUL and move to next one */
|
|
}
|
|
sport = atoi(sports);
|
|
sserv = 0;
|
|
if (sport == 0) {
|
|
sserv = 1;
|
|
sport = net_service_lookup(sports);
|
|
if (!sport) {
|
|
logeventf(ssh, "Service lookup failed for source"
|
|
" port \"%s\"", sports);
|
|
}
|
|
}
|
|
if (sport && dport) {
|
|
/* Set up a description of the source port. */
|
|
struct ssh_portfwd *pfrec, *epfrec;
|
|
|
|
pfrec = snew(struct ssh_portfwd);
|
|
pfrec->type = type;
|
|
pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
|
|
pfrec->sserv = sserv ? dupstr(sports) : NULL;
|
|
pfrec->sport = sport;
|
|
pfrec->daddr = *host ? dupstr(host) : NULL;
|
|
pfrec->dserv = dserv ? dupstr(dports) : NULL;
|
|
pfrec->dport = dport;
|
|
pfrec->local = NULL;
|
|
pfrec->remote = NULL;
|
|
pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
|
|
address_family == '6' ? ADDRTYPE_IPV6 :
|
|
ADDRTYPE_UNSPEC);
|
|
|
|
epfrec = add234(ssh->portfwds, pfrec);
|
|
if (epfrec != pfrec) {
|
|
if (epfrec->status == DESTROY) {
|
|
/*
|
|
* We already have a port forwarding up and running
|
|
* with precisely these parameters. Hence, no need
|
|
* to do anything; simply re-tag the existing one
|
|
* as KEEP.
|
|
*/
|
|
epfrec->status = KEEP;
|
|
}
|
|
/*
|
|
* Anything else indicates that there was a duplicate
|
|
* in our input, which we'll silently ignore.
|
|
*/
|
|
free_portfwd(pfrec);
|
|
} else {
|
|
pfrec->status = CREATE;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now go through and destroy any port forwardings which were
|
|
* not re-enabled.
|
|
*/
|
|
for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
|
|
if (epf->status == DESTROY) {
|
|
char *message;
|
|
|
|
message = dupprintf("%s port forwarding from %s%s%d",
|
|
epf->type == 'L' ? "local" :
|
|
epf->type == 'R' ? "remote" : "dynamic",
|
|
epf->saddr ? epf->saddr : "",
|
|
epf->saddr ? ":" : "",
|
|
epf->sport);
|
|
|
|
if (epf->type != 'D') {
|
|
char *msg2 = dupprintf("%s to %s:%d", message,
|
|
epf->daddr, epf->dport);
|
|
sfree(message);
|
|
message = msg2;
|
|
}
|
|
|
|
logeventf(ssh, "Cancelling %s", message);
|
|
sfree(message);
|
|
|
|
if (epf->remote) {
|
|
struct ssh_rportfwd *rpf = epf->remote;
|
|
struct Packet *pktout;
|
|
|
|
/*
|
|
* Cancel the port forwarding at the server
|
|
* end.
|
|
*/
|
|
if (ssh->version == 1) {
|
|
/*
|
|
* We cannot cancel listening ports on the
|
|
* server side in SSH-1! There's no message
|
|
* to support it. Instead, we simply remove
|
|
* the rportfwd record from the local end
|
|
* so that any connections the server tries
|
|
* to make on it are rejected.
|
|
*/
|
|
} else {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
|
|
ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
|
|
ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
|
|
if (epf->saddr) {
|
|
ssh2_pkt_addstring(pktout, epf->saddr);
|
|
} else if (ssh->cfg.rport_acceptall) {
|
|
/* XXX: ssh->cfg.rport_acceptall may not represent
|
|
* what was used to open the original connection,
|
|
* since it's reconfigurable. */
|
|
ssh2_pkt_addstring(pktout, "0.0.0.0");
|
|
} else {
|
|
ssh2_pkt_addstring(pktout, "127.0.0.1");
|
|
}
|
|
ssh2_pkt_adduint32(pktout, epf->sport);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
|
|
del234(ssh->rportfwds, rpf);
|
|
free_rportfwd(rpf);
|
|
} else if (epf->local) {
|
|
pfd_terminate(epf->local);
|
|
}
|
|
|
|
delpos234(ssh->portfwds, i);
|
|
free_portfwd(epf);
|
|
i--; /* so we don't skip one in the list */
|
|
}
|
|
|
|
/*
|
|
* And finally, set up any new port forwardings (status==CREATE).
|
|
*/
|
|
for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
|
|
if (epf->status == CREATE) {
|
|
char *sportdesc, *dportdesc;
|
|
sportdesc = dupprintf("%s%s%s%s%d%s",
|
|
epf->saddr ? epf->saddr : "",
|
|
epf->saddr ? ":" : "",
|
|
epf->sserv ? epf->sserv : "",
|
|
epf->sserv ? "(" : "",
|
|
epf->sport,
|
|
epf->sserv ? ")" : "");
|
|
if (epf->type == 'D') {
|
|
dportdesc = NULL;
|
|
} else {
|
|
dportdesc = dupprintf("%s:%s%s%d%s",
|
|
epf->daddr,
|
|
epf->dserv ? epf->dserv : "",
|
|
epf->dserv ? "(" : "",
|
|
epf->dport,
|
|
epf->dserv ? ")" : "");
|
|
}
|
|
|
|
if (epf->type == 'L') {
|
|
const char *err = pfd_addforward(epf->daddr, epf->dport,
|
|
epf->saddr, epf->sport,
|
|
ssh, cfg,
|
|
&epf->local,
|
|
epf->addressfamily);
|
|
|
|
logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
|
|
epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
|
|
epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
|
|
sportdesc, dportdesc,
|
|
err ? " failed: " : "", err ? err : "");
|
|
} else if (epf->type == 'D') {
|
|
const char *err = pfd_addforward(NULL, -1,
|
|
epf->saddr, epf->sport,
|
|
ssh, cfg,
|
|
&epf->local,
|
|
epf->addressfamily);
|
|
|
|
logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
|
|
epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
|
|
epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
|
|
sportdesc,
|
|
err ? " failed: " : "", err ? err : "");
|
|
} else {
|
|
struct ssh_rportfwd *pf;
|
|
|
|
/*
|
|
* Ensure the remote port forwardings tree exists.
|
|
*/
|
|
if (!ssh->rportfwds) {
|
|
if (ssh->version == 1)
|
|
ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
|
|
else
|
|
ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
|
|
}
|
|
|
|
pf = snew(struct ssh_rportfwd);
|
|
strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
|
|
pf->dhost[lenof(pf->dhost)-1] = '\0';
|
|
pf->dport = epf->dport;
|
|
pf->sport = epf->sport;
|
|
if (add234(ssh->rportfwds, pf) != pf) {
|
|
logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
|
|
epf->daddr, epf->dport);
|
|
sfree(pf);
|
|
} else {
|
|
logeventf(ssh, "Requesting remote port %s"
|
|
" forward to %s", sportdesc, dportdesc);
|
|
|
|
pf->sportdesc = sportdesc;
|
|
sportdesc = NULL;
|
|
epf->remote = pf;
|
|
pf->pfrec = epf;
|
|
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
|
|
PKT_INT, epf->sport,
|
|
PKT_STR, epf->daddr,
|
|
PKT_INT, epf->dport,
|
|
PKT_END);
|
|
ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
|
|
SSH1_SMSG_FAILURE,
|
|
ssh_rportfwd_succfail, pf);
|
|
} else {
|
|
struct Packet *pktout;
|
|
pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
|
|
ssh2_pkt_addstring(pktout, "tcpip-forward");
|
|
ssh2_pkt_addbool(pktout, 1);/* want reply */
|
|
if (epf->saddr) {
|
|
ssh2_pkt_addstring(pktout, epf->saddr);
|
|
} else if (cfg->rport_acceptall) {
|
|
ssh2_pkt_addstring(pktout, "0.0.0.0");
|
|
} else {
|
|
ssh2_pkt_addstring(pktout, "127.0.0.1");
|
|
}
|
|
ssh2_pkt_adduint32(pktout, epf->sport);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
|
|
ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
|
|
SSH2_MSG_REQUEST_FAILURE,
|
|
ssh_rportfwd_succfail, pf);
|
|
}
|
|
}
|
|
}
|
|
sfree(sportdesc);
|
|
sfree(dportdesc);
|
|
}
|
|
}
|
|
|
|
static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
char *string;
|
|
int stringlen, bufsize;
|
|
|
|
ssh_pkt_getstring(pktin, &string, &stringlen);
|
|
if (string == NULL) {
|
|
bombout(("Incoming terminal data packet was badly formed"));
|
|
return;
|
|
}
|
|
|
|
bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
|
|
string, stringlen);
|
|
if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
|
|
ssh->v1_stdout_throttling = 1;
|
|
ssh_throttle_conn(ssh, +1);
|
|
}
|
|
}
|
|
|
|
static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Remote side is trying to open a channel to talk to our
|
|
* X-Server. Give them back a local channel number. */
|
|
struct ssh_channel *c;
|
|
int remoteid = ssh_pkt_getuint32(pktin);
|
|
|
|
logevent("Received X11 connect request");
|
|
/* Refuse if X11 forwarding is disabled. */
|
|
if (!ssh->X11_fwd_enabled) {
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, remoteid, PKT_END);
|
|
logevent("Rejected X11 connect request");
|
|
} else {
|
|
c = snew(struct ssh_channel);
|
|
c->ssh = ssh;
|
|
|
|
if (x11_init(&c->u.x11.s, ssh->x11disp, c,
|
|
NULL, -1, &ssh->cfg) != NULL) {
|
|
logevent("Opening X11 forward connection failed");
|
|
sfree(c);
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, remoteid, PKT_END);
|
|
} else {
|
|
logevent
|
|
("Opening X11 forward connection succeeded");
|
|
c->remoteid = remoteid;
|
|
c->halfopen = FALSE;
|
|
c->localid = alloc_channel_id(ssh);
|
|
c->closes = 0;
|
|
c->throttling_conn = 0;
|
|
c->type = CHAN_X11; /* identify channel type */
|
|
add234(ssh->channels, c);
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
|
|
PKT_INT, c->remoteid, PKT_INT,
|
|
c->localid, PKT_END);
|
|
logevent("Opened X11 forward channel");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Remote side is trying to open a channel to talk to our
|
|
* agent. Give them back a local channel number. */
|
|
struct ssh_channel *c;
|
|
int remoteid = ssh_pkt_getuint32(pktin);
|
|
|
|
/* Refuse if agent forwarding is disabled. */
|
|
if (!ssh->agentfwd_enabled) {
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, remoteid, PKT_END);
|
|
} else {
|
|
c = snew(struct ssh_channel);
|
|
c->ssh = ssh;
|
|
c->remoteid = remoteid;
|
|
c->halfopen = FALSE;
|
|
c->localid = alloc_channel_id(ssh);
|
|
c->closes = 0;
|
|
c->throttling_conn = 0;
|
|
c->type = CHAN_AGENT; /* identify channel type */
|
|
c->u.a.lensofar = 0;
|
|
add234(ssh->channels, c);
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
|
|
PKT_INT, c->remoteid, PKT_INT, c->localid,
|
|
PKT_END);
|
|
}
|
|
}
|
|
|
|
static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Remote side is trying to open a channel to talk to a
|
|
* forwarded port. Give them back a local channel number. */
|
|
struct ssh_channel *c;
|
|
struct ssh_rportfwd pf, *pfp;
|
|
int remoteid;
|
|
int hostsize, port;
|
|
char *host;
|
|
const char *e;
|
|
c = snew(struct ssh_channel);
|
|
c->ssh = ssh;
|
|
|
|
remoteid = ssh_pkt_getuint32(pktin);
|
|
ssh_pkt_getstring(pktin, &host, &hostsize);
|
|
port = ssh_pkt_getuint32(pktin);
|
|
|
|
if (hostsize >= lenof(pf.dhost))
|
|
hostsize = lenof(pf.dhost)-1;
|
|
memcpy(pf.dhost, host, hostsize);
|
|
pf.dhost[hostsize] = '\0';
|
|
pf.dport = port;
|
|
pfp = find234(ssh->rportfwds, &pf, NULL);
|
|
|
|
if (pfp == NULL) {
|
|
logeventf(ssh, "Rejected remote port open request for %s:%d",
|
|
pf.dhost, port);
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, remoteid, PKT_END);
|
|
} else {
|
|
logeventf(ssh, "Received remote port open request for %s:%d",
|
|
pf.dhost, port);
|
|
e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
|
|
c, &ssh->cfg, pfp->pfrec->addressfamily);
|
|
if (e != NULL) {
|
|
logeventf(ssh, "Port open failed: %s", e);
|
|
sfree(c);
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, remoteid, PKT_END);
|
|
} else {
|
|
c->remoteid = remoteid;
|
|
c->halfopen = FALSE;
|
|
c->localid = alloc_channel_id(ssh);
|
|
c->closes = 0;
|
|
c->throttling_conn = 0;
|
|
c->type = CHAN_SOCKDATA; /* identify channel type */
|
|
add234(ssh->channels, c);
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
|
|
PKT_INT, c->remoteid, PKT_INT,
|
|
c->localid, PKT_END);
|
|
logevent("Forwarded port opened successfully");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
unsigned int remoteid = ssh_pkt_getuint32(pktin);
|
|
unsigned int localid = ssh_pkt_getuint32(pktin);
|
|
struct ssh_channel *c;
|
|
|
|
c = find234(ssh->channels, &remoteid, ssh_channelfind);
|
|
if (c && c->type == CHAN_SOCKDATA_DORMANT) {
|
|
c->remoteid = localid;
|
|
c->halfopen = FALSE;
|
|
c->type = CHAN_SOCKDATA;
|
|
c->throttling_conn = 0;
|
|
pfd_confirm(c->u.pfd.s);
|
|
}
|
|
|
|
if (c && c->closes) {
|
|
/*
|
|
* We have a pending close on this channel,
|
|
* which we decided on before the server acked
|
|
* the channel open. So now we know the
|
|
* remoteid, we can close it again.
|
|
*/
|
|
send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
|
|
PKT_INT, c->remoteid, PKT_END);
|
|
}
|
|
}
|
|
|
|
static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
unsigned int remoteid = ssh_pkt_getuint32(pktin);
|
|
struct ssh_channel *c;
|
|
|
|
c = find234(ssh->channels, &remoteid, ssh_channelfind);
|
|
if (c && c->type == CHAN_SOCKDATA_DORMANT) {
|
|
logevent("Forwarded connection refused by server");
|
|
pfd_close(c->u.pfd.s);
|
|
del234(ssh->channels, c);
|
|
sfree(c);
|
|
}
|
|
}
|
|
|
|
static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Remote side closes a channel. */
|
|
unsigned i = ssh_pkt_getuint32(pktin);
|
|
struct ssh_channel *c;
|
|
c = find234(ssh->channels, &i, ssh_channelfind);
|
|
if (c && !c->halfopen) {
|
|
int closetype;
|
|
closetype =
|
|
(pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
|
|
|
|
if ((c->closes == 0) && (c->type == CHAN_X11)) {
|
|
logevent("Forwarded X11 connection terminated");
|
|
assert(c->u.x11.s != NULL);
|
|
x11_close(c->u.x11.s);
|
|
c->u.x11.s = NULL;
|
|
}
|
|
if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
|
|
logevent("Forwarded port closed");
|
|
assert(c->u.pfd.s != NULL);
|
|
pfd_close(c->u.pfd.s);
|
|
c->u.pfd.s = NULL;
|
|
}
|
|
|
|
c->closes |= (closetype << 2); /* seen this message */
|
|
if (!(c->closes & closetype)) {
|
|
send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
|
|
PKT_END);
|
|
c->closes |= closetype; /* sent it too */
|
|
}
|
|
|
|
if (c->closes == 15) {
|
|
del234(ssh->channels, c);
|
|
sfree(c);
|
|
}
|
|
} else {
|
|
bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
|
|
pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
|
|
"_CONFIRMATION", c ? "half-open" : "nonexistent",
|
|
i));
|
|
}
|
|
}
|
|
|
|
static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Data sent down one of our channels. */
|
|
int i = ssh_pkt_getuint32(pktin);
|
|
char *p;
|
|
int len;
|
|
struct ssh_channel *c;
|
|
|
|
ssh_pkt_getstring(pktin, &p, &len);
|
|
|
|
c = find234(ssh->channels, &i, ssh_channelfind);
|
|
if (c) {
|
|
int bufsize = 0;
|
|
switch (c->type) {
|
|
case CHAN_X11:
|
|
bufsize = x11_send(c->u.x11.s, p, len);
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
bufsize = pfd_send(c->u.pfd.s, p, len);
|
|
break;
|
|
case CHAN_AGENT:
|
|
/* Data for an agent message. Buffer it. */
|
|
while (len > 0) {
|
|
if (c->u.a.lensofar < 4) {
|
|
unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
|
|
memcpy(c->u.a.msglen + c->u.a.lensofar, p,
|
|
l);
|
|
p += l;
|
|
len -= l;
|
|
c->u.a.lensofar += l;
|
|
}
|
|
if (c->u.a.lensofar == 4) {
|
|
c->u.a.totallen =
|
|
4 + GET_32BIT(c->u.a.msglen);
|
|
c->u.a.message = snewn(c->u.a.totallen,
|
|
unsigned char);
|
|
memcpy(c->u.a.message, c->u.a.msglen, 4);
|
|
}
|
|
if (c->u.a.lensofar >= 4 && len > 0) {
|
|
unsigned int l =
|
|
min(c->u.a.totallen - c->u.a.lensofar,
|
|
(unsigned)len);
|
|
memcpy(c->u.a.message + c->u.a.lensofar, p,
|
|
l);
|
|
p += l;
|
|
len -= l;
|
|
c->u.a.lensofar += l;
|
|
}
|
|
if (c->u.a.lensofar == c->u.a.totallen) {
|
|
void *reply;
|
|
int replylen;
|
|
if (agent_query(c->u.a.message,
|
|
c->u.a.totallen,
|
|
&reply, &replylen,
|
|
ssh_agentf_callback, c))
|
|
ssh_agentf_callback(c, reply, replylen);
|
|
sfree(c->u.a.message);
|
|
c->u.a.lensofar = 0;
|
|
}
|
|
}
|
|
bufsize = 0; /* agent channels never back up */
|
|
break;
|
|
}
|
|
if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
|
|
c->throttling_conn = 1;
|
|
ssh_throttle_conn(ssh, +1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
ssh->exitcode = ssh_pkt_getuint32(pktin);
|
|
logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
|
|
send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
|
|
/*
|
|
* In case `helpful' firewalls or proxies tack
|
|
* extra human-readable text on the end of the
|
|
* session which we might mistake for another
|
|
* encrypted packet, we close the session once
|
|
* we've sent EXIT_CONFIRMATION.
|
|
*/
|
|
ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
|
|
}
|
|
|
|
/* Helper function to deal with sending tty modes for REQUEST_PTY */
|
|
static void ssh1_send_ttymode(void *data, char *mode, char *val)
|
|
{
|
|
struct Packet *pktout = (struct Packet *)data;
|
|
int i = 0;
|
|
unsigned int arg = 0;
|
|
while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
|
|
if (i == lenof(ssh_ttymodes)) return;
|
|
switch (ssh_ttymodes[i].type) {
|
|
case TTY_OP_CHAR:
|
|
arg = ssh_tty_parse_specchar(val);
|
|
break;
|
|
case TTY_OP_BOOL:
|
|
arg = ssh_tty_parse_boolean(val);
|
|
break;
|
|
}
|
|
ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
|
|
ssh2_pkt_addbyte(pktout, arg);
|
|
}
|
|
|
|
|
|
static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
|
|
struct Packet *pktin)
|
|
{
|
|
crBegin(ssh->do_ssh1_connection_crstate);
|
|
|
|
ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
|
|
ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
|
|
ssh1_smsg_stdout_stderr_data;
|
|
|
|
ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
|
|
ssh1_msg_channel_open_confirmation;
|
|
ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
|
|
ssh1_msg_channel_open_failure;
|
|
ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
|
|
ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
|
|
ssh1_msg_channel_close;
|
|
ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
|
|
ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
|
|
|
|
if (ssh->cfg.agentfwd && agent_exists()) {
|
|
logevent("Requesting agent forwarding");
|
|
send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
|
|
do {
|
|
crReturnV;
|
|
} while (!pktin);
|
|
if (pktin->type != SSH1_SMSG_SUCCESS
|
|
&& pktin->type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crStopV;
|
|
} else if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
logevent("Agent forwarding refused");
|
|
} else {
|
|
logevent("Agent forwarding enabled");
|
|
ssh->agentfwd_enabled = TRUE;
|
|
ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
|
|
}
|
|
}
|
|
|
|
if (ssh->cfg.x11_forward &&
|
|
(ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
|
|
ssh->cfg.x11_auth, &ssh->cfg))) {
|
|
logevent("Requesting X11 forwarding");
|
|
/*
|
|
* Note that while we blank the X authentication data here, we don't
|
|
* take any special action to blank the start of an X11 channel,
|
|
* so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
|
|
* without having session blanking enabled is likely to leak your
|
|
* cookie into the log.
|
|
*/
|
|
if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
|
|
send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
|
|
PKT_STR, ssh->x11disp->remoteauthprotoname,
|
|
PKTT_PASSWORD,
|
|
PKT_STR, ssh->x11disp->remoteauthdatastring,
|
|
PKTT_OTHER,
|
|
PKT_INT, ssh->x11disp->screennum,
|
|
PKT_END);
|
|
} else {
|
|
send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
|
|
PKT_STR, ssh->x11disp->remoteauthprotoname,
|
|
PKTT_PASSWORD,
|
|
PKT_STR, ssh->x11disp->remoteauthdatastring,
|
|
PKTT_OTHER,
|
|
PKT_END);
|
|
}
|
|
do {
|
|
crReturnV;
|
|
} while (!pktin);
|
|
if (pktin->type != SSH1_SMSG_SUCCESS
|
|
&& pktin->type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crStopV;
|
|
} else if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
logevent("X11 forwarding refused");
|
|
} else {
|
|
logevent("X11 forwarding enabled");
|
|
ssh->X11_fwd_enabled = TRUE;
|
|
ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
|
|
}
|
|
}
|
|
|
|
ssh_setup_portfwd(ssh, &ssh->cfg);
|
|
ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
|
|
|
|
if (!ssh->cfg.nopty) {
|
|
struct Packet *pkt;
|
|
/* Unpick the terminal-speed string. */
|
|
/* XXX perhaps we should allow no speeds to be sent. */
|
|
ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
|
|
sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
|
|
/* Send the pty request. */
|
|
pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
|
|
ssh_pkt_addstring(pkt, ssh->cfg.termtype);
|
|
ssh_pkt_adduint32(pkt, ssh->term_height);
|
|
ssh_pkt_adduint32(pkt, ssh->term_width);
|
|
ssh_pkt_adduint32(pkt, 0); /* width in pixels */
|
|
ssh_pkt_adduint32(pkt, 0); /* height in pixels */
|
|
parse_ttymodes(ssh, ssh->cfg.ttymodes,
|
|
ssh1_send_ttymode, (void *)pkt);
|
|
ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
|
|
ssh_pkt_adduint32(pkt, ssh->ispeed);
|
|
ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
|
|
ssh_pkt_adduint32(pkt, ssh->ospeed);
|
|
ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
|
|
s_wrpkt(ssh, pkt);
|
|
ssh->state = SSH_STATE_INTERMED;
|
|
do {
|
|
crReturnV;
|
|
} while (!pktin);
|
|
if (pktin->type != SSH1_SMSG_SUCCESS
|
|
&& pktin->type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crStopV;
|
|
} else if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
c_write_str(ssh, "Server refused to allocate pty\r\n");
|
|
ssh->editing = ssh->echoing = 1;
|
|
}
|
|
logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
|
|
ssh->ospeed, ssh->ispeed);
|
|
} else {
|
|
ssh->editing = ssh->echoing = 1;
|
|
}
|
|
|
|
if (ssh->cfg.compression) {
|
|
send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
|
|
do {
|
|
crReturnV;
|
|
} while (!pktin);
|
|
if (pktin->type != SSH1_SMSG_SUCCESS
|
|
&& pktin->type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crStopV;
|
|
} else if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
c_write_str(ssh, "Server refused to compress\r\n");
|
|
}
|
|
logevent("Started compression");
|
|
ssh->v1_compressing = TRUE;
|
|
ssh->cs_comp_ctx = zlib_compress_init();
|
|
logevent("Initialised zlib (RFC1950) compression");
|
|
ssh->sc_comp_ctx = zlib_decompress_init();
|
|
logevent("Initialised zlib (RFC1950) decompression");
|
|
}
|
|
|
|
/*
|
|
* Start the shell or command.
|
|
*
|
|
* Special case: if the first-choice command is an SSH-2
|
|
* subsystem (hence not usable here) and the second choice
|
|
* exists, we fall straight back to that.
|
|
*/
|
|
{
|
|
char *cmd = ssh->cfg.remote_cmd_ptr;
|
|
|
|
if (!cmd) cmd = ssh->cfg.remote_cmd;
|
|
|
|
if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
|
|
cmd = ssh->cfg.remote_cmd_ptr2;
|
|
ssh->fallback_cmd = TRUE;
|
|
}
|
|
if (*cmd)
|
|
send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
|
|
else
|
|
send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
|
|
logevent("Started session");
|
|
}
|
|
|
|
ssh->state = SSH_STATE_SESSION;
|
|
if (ssh->size_needed)
|
|
ssh_size(ssh, ssh->term_width, ssh->term_height);
|
|
if (ssh->eof_needed)
|
|
ssh_special(ssh, TS_EOF);
|
|
|
|
if (ssh->ldisc)
|
|
ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
|
|
ssh->send_ok = 1;
|
|
ssh->channels = newtree234(ssh_channelcmp);
|
|
while (1) {
|
|
|
|
/*
|
|
* By this point, most incoming packets are already being
|
|
* handled by the dispatch table, and we need only pay
|
|
* attention to the unusual ones.
|
|
*/
|
|
|
|
crReturnV;
|
|
if (pktin) {
|
|
if (pktin->type == SSH1_SMSG_SUCCESS) {
|
|
/* may be from EXEC_SHELL on some servers */
|
|
} else if (pktin->type == SSH1_SMSG_FAILURE) {
|
|
/* may be from EXEC_SHELL on some servers
|
|
* if no pty is available or in other odd cases. Ignore */
|
|
} else {
|
|
bombout(("Strange packet received: type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
} else {
|
|
while (inlen > 0) {
|
|
int len = min(inlen, 512);
|
|
send_packet(ssh, SSH1_CMSG_STDIN_DATA,
|
|
PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
|
|
PKTT_OTHER, PKT_END);
|
|
in += len;
|
|
inlen -= len;
|
|
}
|
|
}
|
|
}
|
|
|
|
crFinishV;
|
|
}
|
|
|
|
/*
|
|
* Handle the top-level SSH-2 protocol.
|
|
*/
|
|
static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
char *msg;
|
|
int msglen;
|
|
|
|
ssh_pkt_getstring(pktin, &msg, &msglen);
|
|
logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
|
|
}
|
|
|
|
static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* log reason code in disconnect message */
|
|
char *msg;
|
|
int msglen;
|
|
|
|
ssh_pkt_getstring(pktin, &msg, &msglen);
|
|
bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
|
|
}
|
|
|
|
static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Do nothing, because we're ignoring it! Duhh. */
|
|
}
|
|
|
|
static void ssh1_protocol_setup(Ssh ssh)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Most messages are handled by the coroutines.
|
|
*/
|
|
for (i = 0; i < 256; i++)
|
|
ssh->packet_dispatch[i] = NULL;
|
|
|
|
/*
|
|
* These special message types we install handlers for.
|
|
*/
|
|
ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
|
|
ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
|
|
ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
|
|
}
|
|
|
|
static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pktin)
|
|
{
|
|
unsigned char *in=(unsigned char*)vin;
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return;
|
|
|
|
if (pktin && ssh->packet_dispatch[pktin->type]) {
|
|
ssh->packet_dispatch[pktin->type](ssh, pktin);
|
|
return;
|
|
}
|
|
|
|
if (!ssh->protocol_initial_phase_done) {
|
|
if (do_ssh1_login(ssh, in, inlen, pktin))
|
|
ssh->protocol_initial_phase_done = TRUE;
|
|
else
|
|
return;
|
|
}
|
|
|
|
do_ssh1_connection(ssh, in, inlen, pktin);
|
|
}
|
|
|
|
/*
|
|
* Utility routine for decoding comma-separated strings in KEXINIT.
|
|
*/
|
|
static int in_commasep_string(char *needle, char *haystack, int haylen)
|
|
{
|
|
int needlen;
|
|
if (!needle || !haystack) /* protect against null pointers */
|
|
return 0;
|
|
needlen = strlen(needle);
|
|
while (1) {
|
|
/*
|
|
* Is it at the start of the string?
|
|
*/
|
|
if (haylen >= needlen && /* haystack is long enough */
|
|
!memcmp(needle, haystack, needlen) && /* initial match */
|
|
(haylen == needlen || haystack[needlen] == ',')
|
|
/* either , or EOS follows */
|
|
)
|
|
return 1;
|
|
/*
|
|
* If not, search for the next comma and resume after that.
|
|
* If no comma found, terminate.
|
|
*/
|
|
while (haylen > 0 && *haystack != ',')
|
|
haylen--, haystack++;
|
|
if (haylen == 0)
|
|
return 0;
|
|
haylen--, haystack++; /* skip over comma itself */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Similar routine for checking whether we have the first string in a list.
|
|
*/
|
|
static int first_in_commasep_string(char *needle, char *haystack, int haylen)
|
|
{
|
|
int needlen;
|
|
if (!needle || !haystack) /* protect against null pointers */
|
|
return 0;
|
|
needlen = strlen(needle);
|
|
/*
|
|
* Is it at the start of the string?
|
|
*/
|
|
if (haylen >= needlen && /* haystack is long enough */
|
|
!memcmp(needle, haystack, needlen) && /* initial match */
|
|
(haylen == needlen || haystack[needlen] == ',')
|
|
/* either , or EOS follows */
|
|
)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* SSH-2 key creation method.
|
|
* (Currently assumes 2 lots of any hash are sufficient to generate
|
|
* keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
|
|
*/
|
|
#define SSH2_MKKEY_ITERS (2)
|
|
static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
|
|
unsigned char *keyspace)
|
|
{
|
|
const struct ssh_hash *h = ssh->kex->hash;
|
|
void *s;
|
|
/* First hlen bytes. */
|
|
s = h->init();
|
|
if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
|
|
hash_mpint(h, s, K);
|
|
h->bytes(s, H, h->hlen);
|
|
h->bytes(s, &chr, 1);
|
|
h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
|
|
h->final(s, keyspace);
|
|
/* Next hlen bytes. */
|
|
s = h->init();
|
|
if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
|
|
hash_mpint(h, s, K);
|
|
h->bytes(s, H, h->hlen);
|
|
h->bytes(s, keyspace, h->hlen);
|
|
h->final(s, keyspace + h->hlen);
|
|
}
|
|
|
|
/*
|
|
* Handle the SSH-2 transport layer.
|
|
*/
|
|
static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pktin)
|
|
{
|
|
unsigned char *in = (unsigned char *)vin;
|
|
struct do_ssh2_transport_state {
|
|
int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
|
|
Bignum p, g, e, f, K;
|
|
void *our_kexinit;
|
|
int our_kexinitlen;
|
|
int kex_init_value, kex_reply_value;
|
|
const struct ssh_mac **maclist;
|
|
int nmacs;
|
|
const struct ssh2_cipher *cscipher_tobe;
|
|
const struct ssh2_cipher *sccipher_tobe;
|
|
const struct ssh_mac *csmac_tobe;
|
|
const struct ssh_mac *scmac_tobe;
|
|
const struct ssh_compress *cscomp_tobe;
|
|
const struct ssh_compress *sccomp_tobe;
|
|
char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
|
|
int hostkeylen, siglen, rsakeylen;
|
|
void *hkey; /* actual host key */
|
|
void *rsakey; /* for RSA kex */
|
|
unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
|
|
int n_preferred_kex;
|
|
const struct ssh_kexes *preferred_kex[KEX_MAX];
|
|
int n_preferred_ciphers;
|
|
const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
|
|
const struct ssh_compress *preferred_comp;
|
|
int got_session_id, activated_authconn;
|
|
struct Packet *pktout;
|
|
int dlgret;
|
|
int guessok;
|
|
int ignorepkt;
|
|
};
|
|
crState(do_ssh2_transport_state);
|
|
|
|
crBegin(ssh->do_ssh2_transport_crstate);
|
|
|
|
s->cscipher_tobe = s->sccipher_tobe = NULL;
|
|
s->csmac_tobe = s->scmac_tobe = NULL;
|
|
s->cscomp_tobe = s->sccomp_tobe = NULL;
|
|
|
|
s->got_session_id = s->activated_authconn = FALSE;
|
|
|
|
/*
|
|
* Be prepared to work around the buggy MAC problem.
|
|
*/
|
|
if (ssh->remote_bugs & BUG_SSH2_HMAC)
|
|
s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
|
|
else
|
|
s->maclist = macs, s->nmacs = lenof(macs);
|
|
|
|
begin_key_exchange:
|
|
ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
|
|
{
|
|
int i, j, commalist_started;
|
|
|
|
/*
|
|
* Set up the preferred key exchange. (NULL => warn below here)
|
|
*/
|
|
s->n_preferred_kex = 0;
|
|
for (i = 0; i < KEX_MAX; i++) {
|
|
switch (ssh->cfg.ssh_kexlist[i]) {
|
|
case KEX_DHGEX:
|
|
s->preferred_kex[s->n_preferred_kex++] =
|
|
&ssh_diffiehellman_gex;
|
|
break;
|
|
case KEX_DHGROUP14:
|
|
s->preferred_kex[s->n_preferred_kex++] =
|
|
&ssh_diffiehellman_group14;
|
|
break;
|
|
case KEX_DHGROUP1:
|
|
s->preferred_kex[s->n_preferred_kex++] =
|
|
&ssh_diffiehellman_group1;
|
|
break;
|
|
case KEX_RSA:
|
|
s->preferred_kex[s->n_preferred_kex++] =
|
|
&ssh_rsa_kex;
|
|
break;
|
|
case KEX_WARN:
|
|
/* Flag for later. Don't bother if it's the last in
|
|
* the list. */
|
|
if (i < KEX_MAX - 1) {
|
|
s->preferred_kex[s->n_preferred_kex++] = NULL;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set up the preferred ciphers. (NULL => warn below here)
|
|
*/
|
|
s->n_preferred_ciphers = 0;
|
|
for (i = 0; i < CIPHER_MAX; i++) {
|
|
switch (ssh->cfg.ssh_cipherlist[i]) {
|
|
case CIPHER_BLOWFISH:
|
|
s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
|
|
break;
|
|
case CIPHER_DES:
|
|
if (ssh->cfg.ssh2_des_cbc) {
|
|
s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
|
|
}
|
|
break;
|
|
case CIPHER_3DES:
|
|
s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
|
|
break;
|
|
case CIPHER_AES:
|
|
s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
|
|
break;
|
|
case CIPHER_ARCFOUR:
|
|
s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
|
|
break;
|
|
case CIPHER_WARN:
|
|
/* Flag for later. Don't bother if it's the last in
|
|
* the list. */
|
|
if (i < CIPHER_MAX - 1) {
|
|
s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set up preferred compression.
|
|
*/
|
|
if (ssh->cfg.compression)
|
|
s->preferred_comp = &ssh_zlib;
|
|
else
|
|
s->preferred_comp = &ssh_comp_none;
|
|
|
|
/*
|
|
* Enable queueing of outgoing auth- or connection-layer
|
|
* packets while we are in the middle of a key exchange.
|
|
*/
|
|
ssh->queueing = TRUE;
|
|
|
|
/*
|
|
* Flag that KEX is in progress.
|
|
*/
|
|
ssh->kex_in_progress = TRUE;
|
|
|
|
/*
|
|
* Construct and send our key exchange packet.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
|
|
for (i = 0; i < 16; i++)
|
|
ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
|
|
/* List key exchange algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
commalist_started = 0;
|
|
for (i = 0; i < s->n_preferred_kex; i++) {
|
|
const struct ssh_kexes *k = s->preferred_kex[i];
|
|
if (!k) continue; /* warning flag */
|
|
for (j = 0; j < k->nkexes; j++) {
|
|
if (commalist_started)
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
|
|
commalist_started = 1;
|
|
}
|
|
}
|
|
/* List server host key algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
for (i = 0; i < lenof(hostkey_algs); i++) {
|
|
ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
|
|
if (i < lenof(hostkey_algs) - 1)
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
}
|
|
/* List client->server encryption algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
commalist_started = 0;
|
|
for (i = 0; i < s->n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
|
|
if (!c) continue; /* warning flag */
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
if (commalist_started)
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
|
|
commalist_started = 1;
|
|
}
|
|
}
|
|
/* List server->client encryption algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
commalist_started = 0;
|
|
for (i = 0; i < s->n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
|
|
if (!c) continue; /* warning flag */
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
if (commalist_started)
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
|
|
commalist_started = 1;
|
|
}
|
|
}
|
|
/* List client->server MAC algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
for (i = 0; i < s->nmacs; i++) {
|
|
ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
|
|
if (i < s->nmacs - 1)
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
}
|
|
/* List server->client MAC algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
for (i = 0; i < s->nmacs; i++) {
|
|
ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
|
|
if (i < s->nmacs - 1)
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
}
|
|
/* List client->server compression algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
assert(lenof(compressions) > 1);
|
|
ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
|
|
for (i = 0; i < lenof(compressions); i++) {
|
|
const struct ssh_compress *c = compressions[i];
|
|
if (c != s->preferred_comp) {
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
ssh2_pkt_addstring_str(s->pktout, c->name);
|
|
}
|
|
}
|
|
/* List server->client compression algorithms. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
assert(lenof(compressions) > 1);
|
|
ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
|
|
for (i = 0; i < lenof(compressions); i++) {
|
|
const struct ssh_compress *c = compressions[i];
|
|
if (c != s->preferred_comp) {
|
|
ssh2_pkt_addstring_str(s->pktout, ",");
|
|
ssh2_pkt_addstring_str(s->pktout, c->name);
|
|
}
|
|
}
|
|
/* List client->server languages. Empty list. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
/* List server->client languages. Empty list. */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
/* First KEX packet does _not_ follow, because we're not that brave. */
|
|
ssh2_pkt_addbool(s->pktout, FALSE);
|
|
/* Reserved. */
|
|
ssh2_pkt_adduint32(s->pktout, 0);
|
|
}
|
|
|
|
s->our_kexinitlen = s->pktout->length - 5;
|
|
s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
|
|
memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
|
|
|
|
ssh2_pkt_send_noqueue(ssh, s->pktout);
|
|
|
|
if (!pktin)
|
|
crWaitUntil(pktin);
|
|
|
|
/*
|
|
* Now examine the other side's KEXINIT to see what we're up
|
|
* to.
|
|
*/
|
|
{
|
|
char *str, *preferred;
|
|
int i, j, len;
|
|
|
|
if (pktin->type != SSH2_MSG_KEXINIT) {
|
|
bombout(("expected key exchange packet from server"));
|
|
crStop(0);
|
|
}
|
|
ssh->kex = NULL;
|
|
ssh->hostkey = NULL;
|
|
s->cscipher_tobe = NULL;
|
|
s->sccipher_tobe = NULL;
|
|
s->csmac_tobe = NULL;
|
|
s->scmac_tobe = NULL;
|
|
s->cscomp_tobe = NULL;
|
|
s->sccomp_tobe = NULL;
|
|
s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
|
|
|
|
pktin->savedpos += 16; /* skip garbage cookie */
|
|
ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
|
|
|
|
preferred = NULL;
|
|
for (i = 0; i < s->n_preferred_kex; i++) {
|
|
const struct ssh_kexes *k = s->preferred_kex[i];
|
|
if (!k) {
|
|
s->warn_kex = TRUE;
|
|
} else {
|
|
for (j = 0; j < k->nkexes; j++) {
|
|
if (!preferred) preferred = k->list[j]->name;
|
|
if (in_commasep_string(k->list[j]->name, str, len)) {
|
|
ssh->kex = k->list[j];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (ssh->kex)
|
|
break;
|
|
}
|
|
if (!ssh->kex) {
|
|
bombout(("Couldn't agree a key exchange algorithm (available: %s)",
|
|
str ? str : "(null)"));
|
|
crStop(0);
|
|
}
|
|
/*
|
|
* Note that the server's guess is considered wrong if it doesn't match
|
|
* the first algorithm in our list, even if it's still the algorithm
|
|
* we end up using.
|
|
*/
|
|
s->guessok = first_in_commasep_string(preferred, str, len);
|
|
ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
|
|
for (i = 0; i < lenof(hostkey_algs); i++) {
|
|
if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
|
|
ssh->hostkey = hostkey_algs[i];
|
|
break;
|
|
}
|
|
}
|
|
s->guessok = s->guessok &&
|
|
first_in_commasep_string(hostkey_algs[0]->name, str, len);
|
|
ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
|
|
for (i = 0; i < s->n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
|
|
if (!c) {
|
|
s->warn_cscipher = TRUE;
|
|
} else {
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
if (in_commasep_string(c->list[j]->name, str, len)) {
|
|
s->cscipher_tobe = c->list[j];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (s->cscipher_tobe)
|
|
break;
|
|
}
|
|
if (!s->cscipher_tobe) {
|
|
bombout(("Couldn't agree a client-to-server cipher (available: %s)",
|
|
str ? str : "(null)"));
|
|
crStop(0);
|
|
}
|
|
|
|
ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
|
|
for (i = 0; i < s->n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
|
|
if (!c) {
|
|
s->warn_sccipher = TRUE;
|
|
} else {
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
if (in_commasep_string(c->list[j]->name, str, len)) {
|
|
s->sccipher_tobe = c->list[j];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (s->sccipher_tobe)
|
|
break;
|
|
}
|
|
if (!s->sccipher_tobe) {
|
|
bombout(("Couldn't agree a server-to-client cipher (available: %s)",
|
|
str ? str : "(null)"));
|
|
crStop(0);
|
|
}
|
|
|
|
ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
|
|
for (i = 0; i < s->nmacs; i++) {
|
|
if (in_commasep_string(s->maclist[i]->name, str, len)) {
|
|
s->csmac_tobe = s->maclist[i];
|
|
break;
|
|
}
|
|
}
|
|
ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
|
|
for (i = 0; i < s->nmacs; i++) {
|
|
if (in_commasep_string(s->maclist[i]->name, str, len)) {
|
|
s->scmac_tobe = s->maclist[i];
|
|
break;
|
|
}
|
|
}
|
|
ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
|
|
for (i = 0; i < lenof(compressions) + 1; i++) {
|
|
const struct ssh_compress *c =
|
|
i == 0 ? s->preferred_comp : compressions[i - 1];
|
|
if (in_commasep_string(c->name, str, len)) {
|
|
s->cscomp_tobe = c;
|
|
break;
|
|
}
|
|
}
|
|
ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
|
|
for (i = 0; i < lenof(compressions) + 1; i++) {
|
|
const struct ssh_compress *c =
|
|
i == 0 ? s->preferred_comp : compressions[i - 1];
|
|
if (in_commasep_string(c->name, str, len)) {
|
|
s->sccomp_tobe = c;
|
|
break;
|
|
}
|
|
}
|
|
ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
|
|
ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
|
|
s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
|
|
|
|
if (s->warn_kex) {
|
|
ssh_set_frozen(ssh, 1);
|
|
s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
|
|
ssh->kex->name,
|
|
ssh_dialog_callback, ssh);
|
|
if (s->dlgret < 0) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while"
|
|
" waiting for user response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
s->dlgret = ssh->user_response;
|
|
}
|
|
ssh_set_frozen(ssh, 0);
|
|
if (s->dlgret == 0) {
|
|
ssh_disconnect(ssh, "User aborted at kex warning", NULL,
|
|
0, TRUE);
|
|
crStop(0);
|
|
}
|
|
}
|
|
|
|
if (s->warn_cscipher) {
|
|
ssh_set_frozen(ssh, 1);
|
|
s->dlgret = askalg(ssh->frontend,
|
|
"client-to-server cipher",
|
|
s->cscipher_tobe->name,
|
|
ssh_dialog_callback, ssh);
|
|
if (s->dlgret < 0) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while"
|
|
" waiting for user response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
s->dlgret = ssh->user_response;
|
|
}
|
|
ssh_set_frozen(ssh, 0);
|
|
if (s->dlgret == 0) {
|
|
ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
|
|
0, TRUE);
|
|
crStop(0);
|
|
}
|
|
}
|
|
|
|
if (s->warn_sccipher) {
|
|
ssh_set_frozen(ssh, 1);
|
|
s->dlgret = askalg(ssh->frontend,
|
|
"server-to-client cipher",
|
|
s->sccipher_tobe->name,
|
|
ssh_dialog_callback, ssh);
|
|
if (s->dlgret < 0) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while"
|
|
" waiting for user response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
s->dlgret = ssh->user_response;
|
|
}
|
|
ssh_set_frozen(ssh, 0);
|
|
if (s->dlgret == 0) {
|
|
ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
|
|
0, TRUE);
|
|
crStop(0);
|
|
}
|
|
}
|
|
|
|
ssh->exhash = ssh->kex->hash->init();
|
|
hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
|
|
hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
|
|
hash_string(ssh->kex->hash, ssh->exhash,
|
|
s->our_kexinit, s->our_kexinitlen);
|
|
sfree(s->our_kexinit);
|
|
if (pktin->length > 5)
|
|
hash_string(ssh->kex->hash, ssh->exhash,
|
|
pktin->data + 5, pktin->length - 5);
|
|
|
|
if (s->ignorepkt) /* first_kex_packet_follows */
|
|
crWaitUntil(pktin); /* Ignore packet */
|
|
}
|
|
|
|
if (ssh->kex->main_type == KEXTYPE_DH) {
|
|
/*
|
|
* Work out the number of bits of key we will need from the
|
|
* key exchange. We start with the maximum key length of
|
|
* either cipher...
|
|
*/
|
|
{
|
|
int csbits, scbits;
|
|
|
|
csbits = s->cscipher_tobe->keylen;
|
|
scbits = s->sccipher_tobe->keylen;
|
|
s->nbits = (csbits > scbits ? csbits : scbits);
|
|
}
|
|
/* The keys only have hlen-bit entropy, since they're based on
|
|
* a hash. So cap the key size at hlen bits. */
|
|
if (s->nbits > ssh->kex->hash->hlen * 8)
|
|
s->nbits = ssh->kex->hash->hlen * 8;
|
|
|
|
/*
|
|
* If we're doing Diffie-Hellman group exchange, start by
|
|
* requesting a group.
|
|
*/
|
|
if (!ssh->kex->pdata) {
|
|
logevent("Doing Diffie-Hellman group exchange");
|
|
ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
|
|
/*
|
|
* Work out how big a DH group we will need to allow that
|
|
* much data.
|
|
*/
|
|
s->pbits = 512 << ((s->nbits - 1) / 64);
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, s->pbits);
|
|
ssh2_pkt_send_noqueue(ssh, s->pktout);
|
|
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
|
|
bombout(("expected key exchange group packet from server"));
|
|
crStop(0);
|
|
}
|
|
s->p = ssh2_pkt_getmp(pktin);
|
|
s->g = ssh2_pkt_getmp(pktin);
|
|
if (!s->p || !s->g) {
|
|
bombout(("unable to read mp-ints from incoming group packet"));
|
|
crStop(0);
|
|
}
|
|
ssh->kex_ctx = dh_setup_gex(s->p, s->g);
|
|
s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
|
|
s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
|
|
} else {
|
|
ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
|
|
ssh->kex_ctx = dh_setup_group(ssh->kex);
|
|
s->kex_init_value = SSH2_MSG_KEXDH_INIT;
|
|
s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
|
|
logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
|
|
ssh->kex->groupname);
|
|
}
|
|
|
|
logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
|
|
ssh->kex->hash->text_name);
|
|
/*
|
|
* Now generate and send e for Diffie-Hellman.
|
|
*/
|
|
set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
|
|
s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
|
|
s->pktout = ssh2_pkt_init(s->kex_init_value);
|
|
ssh2_pkt_addmp(s->pktout, s->e);
|
|
ssh2_pkt_send_noqueue(ssh, s->pktout);
|
|
|
|
set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != s->kex_reply_value) {
|
|
bombout(("expected key exchange reply packet from server"));
|
|
crStop(0);
|
|
}
|
|
set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
|
|
ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
|
|
s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
|
|
s->f = ssh2_pkt_getmp(pktin);
|
|
if (!s->f) {
|
|
bombout(("unable to parse key exchange reply packet"));
|
|
crStop(0);
|
|
}
|
|
ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
|
|
|
|
s->K = dh_find_K(ssh->kex_ctx, s->f);
|
|
|
|
/* We assume everything from now on will be quick, and it might
|
|
* involve user interaction. */
|
|
set_busy_status(ssh->frontend, BUSY_NOT);
|
|
|
|
hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
|
|
if (!ssh->kex->pdata) {
|
|
hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
|
|
hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
|
|
hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
|
|
}
|
|
hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
|
|
hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
|
|
|
|
dh_cleanup(ssh->kex_ctx);
|
|
freebn(s->f);
|
|
if (!ssh->kex->pdata) {
|
|
freebn(s->g);
|
|
freebn(s->p);
|
|
}
|
|
} else {
|
|
logeventf(ssh, "Doing RSA key exchange with hash %s",
|
|
ssh->kex->hash->text_name);
|
|
ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
|
|
/*
|
|
* RSA key exchange. First expect a KEXRSA_PUBKEY packet
|
|
* from the server.
|
|
*/
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
|
|
bombout(("expected RSA public key packet from server"));
|
|
crStop(0);
|
|
}
|
|
|
|
ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
|
|
hash_string(ssh->kex->hash, ssh->exhash,
|
|
s->hostkeydata, s->hostkeylen);
|
|
s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
|
|
|
|
{
|
|
char *keydata;
|
|
ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
|
|
s->rsakeydata = snewn(s->rsakeylen, char);
|
|
memcpy(s->rsakeydata, keydata, s->rsakeylen);
|
|
}
|
|
|
|
s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
|
|
if (!s->rsakey) {
|
|
sfree(s->rsakeydata);
|
|
bombout(("unable to parse RSA public key from server"));
|
|
crStop(0);
|
|
}
|
|
|
|
hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
|
|
|
|
/*
|
|
* Next, set up a shared secret K, of precisely KLEN -
|
|
* 2*HLEN - 49 bits, where KLEN is the bit length of the
|
|
* RSA key modulus and HLEN is the bit length of the hash
|
|
* we're using.
|
|
*/
|
|
{
|
|
int klen = ssh_rsakex_klen(s->rsakey);
|
|
int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
|
|
int i, byte = 0;
|
|
unsigned char *kstr1, *kstr2, *outstr;
|
|
int kstr1len, kstr2len, outstrlen;
|
|
|
|
s->K = bn_power_2(nbits - 1);
|
|
|
|
for (i = 0; i < nbits; i++) {
|
|
if ((i & 7) == 0) {
|
|
byte = random_byte();
|
|
}
|
|
bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
|
|
}
|
|
|
|
/*
|
|
* Encode this as an mpint.
|
|
*/
|
|
kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
|
|
kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
|
|
PUT_32BIT(kstr2, kstr1len);
|
|
memcpy(kstr2 + 4, kstr1, kstr1len);
|
|
|
|
/*
|
|
* Encrypt it with the given RSA key.
|
|
*/
|
|
outstrlen = (klen + 7) / 8;
|
|
outstr = snewn(outstrlen, unsigned char);
|
|
ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
|
|
outstr, outstrlen, s->rsakey);
|
|
|
|
/*
|
|
* And send it off in a return packet.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
|
|
ssh2_pkt_send_noqueue(ssh, s->pktout);
|
|
|
|
hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
|
|
|
|
sfree(kstr2);
|
|
sfree(kstr1);
|
|
sfree(outstr);
|
|
}
|
|
|
|
ssh_rsakex_freekey(s->rsakey);
|
|
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
|
|
sfree(s->rsakeydata);
|
|
bombout(("expected signature packet from server"));
|
|
crStop(0);
|
|
}
|
|
|
|
ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
|
|
|
|
sfree(s->rsakeydata);
|
|
}
|
|
|
|
hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
|
|
assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
|
|
ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
|
|
|
|
ssh->kex_ctx = NULL;
|
|
|
|
#if 0
|
|
debug(("Exchange hash is:\n"));
|
|
dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
|
|
#endif
|
|
|
|
if (!s->hkey ||
|
|
!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
|
|
(char *)s->exchange_hash,
|
|
ssh->kex->hash->hlen)) {
|
|
bombout(("Server's host key did not match the signature supplied"));
|
|
crStop(0);
|
|
}
|
|
|
|
/*
|
|
* Authenticate remote host: verify host key. (We've already
|
|
* checked the signature of the exchange hash.)
|
|
*/
|
|
s->keystr = ssh->hostkey->fmtkey(s->hkey);
|
|
s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
|
|
ssh_set_frozen(ssh, 1);
|
|
s->dlgret = verify_ssh_host_key(ssh->frontend,
|
|
ssh->savedhost, ssh->savedport,
|
|
ssh->hostkey->keytype, s->keystr,
|
|
s->fingerprint,
|
|
ssh_dialog_callback, ssh);
|
|
if (s->dlgret < 0) {
|
|
do {
|
|
crReturn(0);
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while waiting"
|
|
" for user host key response"));
|
|
crStop(0);
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
s->dlgret = ssh->user_response;
|
|
}
|
|
ssh_set_frozen(ssh, 0);
|
|
if (s->dlgret == 0) {
|
|
ssh_disconnect(ssh, "User aborted at host key verification", NULL,
|
|
0, TRUE);
|
|
crStop(0);
|
|
}
|
|
if (!s->got_session_id) { /* don't bother logging this in rekeys */
|
|
logevent("Host key fingerprint is:");
|
|
logevent(s->fingerprint);
|
|
}
|
|
sfree(s->fingerprint);
|
|
sfree(s->keystr);
|
|
ssh->hostkey->freekey(s->hkey);
|
|
|
|
/*
|
|
* The exchange hash from the very first key exchange is also
|
|
* the session id, used in session key construction and
|
|
* authentication.
|
|
*/
|
|
if (!s->got_session_id) {
|
|
assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
|
|
memcpy(ssh->v2_session_id, s->exchange_hash,
|
|
sizeof(s->exchange_hash));
|
|
ssh->v2_session_id_len = ssh->kex->hash->hlen;
|
|
assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
|
|
s->got_session_id = TRUE;
|
|
}
|
|
|
|
/*
|
|
* Send SSH2_MSG_NEWKEYS.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
|
|
ssh2_pkt_send_noqueue(ssh, s->pktout);
|
|
ssh->outgoing_data_size = 0; /* start counting from here */
|
|
|
|
/*
|
|
* We've sent client NEWKEYS, so create and initialise
|
|
* client-to-server session keys.
|
|
*/
|
|
if (ssh->cs_cipher_ctx)
|
|
ssh->cscipher->free_context(ssh->cs_cipher_ctx);
|
|
ssh->cscipher = s->cscipher_tobe;
|
|
ssh->cs_cipher_ctx = ssh->cscipher->make_context();
|
|
|
|
if (ssh->cs_mac_ctx)
|
|
ssh->csmac->free_context(ssh->cs_mac_ctx);
|
|
ssh->csmac = s->csmac_tobe;
|
|
ssh->cs_mac_ctx = ssh->csmac->make_context();
|
|
|
|
if (ssh->cs_comp_ctx)
|
|
ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
|
|
ssh->cscomp = s->cscomp_tobe;
|
|
ssh->cs_comp_ctx = ssh->cscomp->compress_init();
|
|
|
|
/*
|
|
* Set IVs on client-to-server keys. Here we use the exchange
|
|
* hash from the _first_ key exchange.
|
|
*/
|
|
{
|
|
unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
|
|
assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
|
|
assert((ssh->cscipher->keylen+7) / 8 <=
|
|
ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
|
|
ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
|
|
assert(ssh->cscipher->blksize <=
|
|
ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
|
|
ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
|
|
assert(ssh->csmac->len <=
|
|
ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
|
|
memset(keyspace, 0, sizeof(keyspace));
|
|
}
|
|
|
|
logeventf(ssh, "Initialised %.200s client->server encryption",
|
|
ssh->cscipher->text_name);
|
|
logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
|
|
ssh->csmac->text_name);
|
|
if (ssh->cscomp->text_name)
|
|
logeventf(ssh, "Initialised %s compression",
|
|
ssh->cscomp->text_name);
|
|
|
|
/*
|
|
* Now our end of the key exchange is complete, we can send all
|
|
* our queued higher-layer packets.
|
|
*/
|
|
ssh->queueing = FALSE;
|
|
ssh2_pkt_queuesend(ssh);
|
|
|
|
/*
|
|
* Expect SSH2_MSG_NEWKEYS from server.
|
|
*/
|
|
crWaitUntil(pktin);
|
|
if (pktin->type != SSH2_MSG_NEWKEYS) {
|
|
bombout(("expected new-keys packet from server"));
|
|
crStop(0);
|
|
}
|
|
ssh->incoming_data_size = 0; /* start counting from here */
|
|
|
|
/*
|
|
* We've seen server NEWKEYS, so create and initialise
|
|
* server-to-client session keys.
|
|
*/
|
|
if (ssh->sc_cipher_ctx)
|
|
ssh->sccipher->free_context(ssh->sc_cipher_ctx);
|
|
ssh->sccipher = s->sccipher_tobe;
|
|
ssh->sc_cipher_ctx = ssh->sccipher->make_context();
|
|
|
|
if (ssh->sc_mac_ctx)
|
|
ssh->scmac->free_context(ssh->sc_mac_ctx);
|
|
ssh->scmac = s->scmac_tobe;
|
|
ssh->sc_mac_ctx = ssh->scmac->make_context();
|
|
|
|
if (ssh->sc_comp_ctx)
|
|
ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
|
|
ssh->sccomp = s->sccomp_tobe;
|
|
ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
|
|
|
|
/*
|
|
* Set IVs on server-to-client keys. Here we use the exchange
|
|
* hash from the _first_ key exchange.
|
|
*/
|
|
{
|
|
unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
|
|
assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
|
|
assert((ssh->sccipher->keylen+7) / 8 <=
|
|
ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
|
|
ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
|
|
assert(ssh->sccipher->blksize <=
|
|
ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
|
|
ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
|
|
assert(ssh->scmac->len <=
|
|
ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
|
|
ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
|
|
memset(keyspace, 0, sizeof(keyspace));
|
|
}
|
|
logeventf(ssh, "Initialised %.200s server->client encryption",
|
|
ssh->sccipher->text_name);
|
|
logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
|
|
ssh->scmac->text_name);
|
|
if (ssh->sccomp->text_name)
|
|
logeventf(ssh, "Initialised %s decompression",
|
|
ssh->sccomp->text_name);
|
|
|
|
/*
|
|
* Free shared secret.
|
|
*/
|
|
freebn(s->K);
|
|
|
|
/*
|
|
* Key exchange is over. Loop straight back round if we have a
|
|
* deferred rekey reason.
|
|
*/
|
|
if (ssh->deferred_rekey_reason) {
|
|
logevent(ssh->deferred_rekey_reason);
|
|
pktin = NULL;
|
|
ssh->deferred_rekey_reason = NULL;
|
|
goto begin_key_exchange;
|
|
}
|
|
|
|
/*
|
|
* Otherwise, schedule a timer for our next rekey.
|
|
*/
|
|
ssh->kex_in_progress = FALSE;
|
|
ssh->last_rekey = GETTICKCOUNT();
|
|
if (ssh->cfg.ssh_rekey_time != 0)
|
|
ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
|
|
ssh2_timer, ssh);
|
|
|
|
/*
|
|
* If this is the first key exchange phase, we must pass the
|
|
* SSH2_MSG_NEWKEYS packet to the next layer, not because it
|
|
* wants to see it but because it will need time to initialise
|
|
* itself before it sees an actual packet. In subsequent key
|
|
* exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
|
|
* it would only confuse the layer above.
|
|
*/
|
|
if (s->activated_authconn) {
|
|
crReturn(0);
|
|
}
|
|
s->activated_authconn = TRUE;
|
|
|
|
/*
|
|
* Now we're encrypting. Begin returning 1 to the protocol main
|
|
* function so that other things can run on top of the
|
|
* transport. If we ever see a KEXINIT, we must go back to the
|
|
* start.
|
|
*
|
|
* We _also_ go back to the start if we see pktin==NULL and
|
|
* inlen==-1, because this is a special signal meaning
|
|
* `initiate client-driven rekey', and `in' contains a message
|
|
* giving the reason for the rekey.
|
|
*/
|
|
while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
|
|
(!pktin && inlen == -1))) {
|
|
wait_for_rekey:
|
|
crReturn(1);
|
|
}
|
|
if (pktin) {
|
|
logevent("Server initiated key re-exchange");
|
|
} else {
|
|
/*
|
|
* Special case: if the server bug is set that doesn't
|
|
* allow rekeying, we give a different log message and
|
|
* continue waiting. (If such a server _initiates_ a rekey,
|
|
* we process it anyway!)
|
|
*/
|
|
if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
|
|
logeventf(ssh, "Server bug prevents key re-exchange (%s)",
|
|
(char *)in);
|
|
/* Reset the counters, so that at least this message doesn't
|
|
* hit the event log _too_ often. */
|
|
ssh->outgoing_data_size = 0;
|
|
ssh->incoming_data_size = 0;
|
|
if (ssh->cfg.ssh_rekey_time != 0) {
|
|
ssh->next_rekey =
|
|
schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
|
|
ssh2_timer, ssh);
|
|
}
|
|
goto wait_for_rekey; /* this is utterly horrid */
|
|
} else {
|
|
logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
|
|
}
|
|
}
|
|
goto begin_key_exchange;
|
|
|
|
crFinish(1);
|
|
}
|
|
|
|
/*
|
|
* Add data to an SSH-2 channel output buffer.
|
|
*/
|
|
static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
|
|
int len)
|
|
{
|
|
bufchain_add(&c->v.v2.outbuffer, buf, len);
|
|
}
|
|
|
|
/*
|
|
* Attempt to send data on an SSH-2 channel.
|
|
*/
|
|
static int ssh2_try_send(struct ssh_channel *c)
|
|
{
|
|
Ssh ssh = c->ssh;
|
|
struct Packet *pktout;
|
|
|
|
while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
|
|
int len;
|
|
void *data;
|
|
bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
|
|
if ((unsigned)len > c->v.v2.remwindow)
|
|
len = c->v.v2.remwindow;
|
|
if ((unsigned)len > c->v.v2.remmaxpkt)
|
|
len = c->v.v2.remmaxpkt;
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_addstring_start(pktout);
|
|
dont_log_data(ssh, pktout, PKTLOG_OMIT);
|
|
ssh2_pkt_addstring_data(pktout, data, len);
|
|
end_log_omission(ssh, pktout);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
bufchain_consume(&c->v.v2.outbuffer, len);
|
|
c->v.v2.remwindow -= len;
|
|
}
|
|
|
|
/*
|
|
* After having sent as much data as we can, return the amount
|
|
* still buffered.
|
|
*/
|
|
return bufchain_size(&c->v.v2.outbuffer);
|
|
}
|
|
|
|
static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
|
|
{
|
|
int bufsize;
|
|
if (c->closes)
|
|
return; /* don't send on closing channels */
|
|
bufsize = ssh2_try_send(c);
|
|
if (bufsize == 0) {
|
|
switch (c->type) {
|
|
case CHAN_MAINSESSION:
|
|
/* stdin need not receive an unthrottle
|
|
* notification since it will be polled */
|
|
break;
|
|
case CHAN_X11:
|
|
x11_unthrottle(c->u.x11.s);
|
|
break;
|
|
case CHAN_AGENT:
|
|
/* agent sockets are request/response and need no
|
|
* buffer management */
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
pfd_unthrottle(c->u.pfd.s);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set up most of a new ssh_channel for SSH-2.
|
|
*/
|
|
static void ssh2_channel_init(struct ssh_channel *c)
|
|
{
|
|
Ssh ssh = c->ssh;
|
|
c->localid = alloc_channel_id(ssh);
|
|
c->closes = 0;
|
|
c->throttling_conn = FALSE;
|
|
c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
|
|
ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
|
|
c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
|
|
c->v.v2.throttle_state = UNTHROTTLED;
|
|
bufchain_init(&c->v.v2.outbuffer);
|
|
}
|
|
|
|
/*
|
|
* Potentially enlarge the window on an SSH-2 channel.
|
|
*/
|
|
static void ssh2_set_window(struct ssh_channel *c, int newwin)
|
|
{
|
|
Ssh ssh = c->ssh;
|
|
|
|
/*
|
|
* Never send WINDOW_ADJUST for a channel that the remote side
|
|
* already thinks it's closed; there's no point, since it won't
|
|
* be sending any more data anyway.
|
|
*/
|
|
if (c->closes != 0)
|
|
return;
|
|
|
|
/*
|
|
* If the remote end has a habit of ignoring maxpkt, limit the
|
|
* window so that it has no choice (assuming it doesn't ignore the
|
|
* window as well).
|
|
*/
|
|
if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
|
|
newwin = OUR_V2_MAXPKT;
|
|
|
|
|
|
/*
|
|
* Only send a WINDOW_ADJUST if there's significantly more window
|
|
* available than the other end thinks there is. This saves us
|
|
* sending a WINDOW_ADJUST for every character in a shell session.
|
|
*
|
|
* "Significant" is arbitrarily defined as half the window size.
|
|
*/
|
|
if (newwin / 2 >= c->v.v2.locwindow) {
|
|
struct Packet *pktout;
|
|
struct winadj *wa;
|
|
|
|
/*
|
|
* In order to keep track of how much window the client
|
|
* actually has available, we'd like it to acknowledge each
|
|
* WINDOW_ADJUST. We can't do that directly, so we accompany
|
|
* it with a CHANNEL_REQUEST that has to be acknowledged.
|
|
*
|
|
* This is only necessary if we're opening the window wide.
|
|
* If we're not, then throughput is being constrained by
|
|
* something other than the maximum window size anyway.
|
|
*
|
|
* We also only send this if the main channel has finished its
|
|
* initial CHANNEL_REQUESTs and installed the default
|
|
* CHANNEL_FAILURE handler, so as not to risk giving it
|
|
* unexpected CHANNEL_FAILUREs.
|
|
*/
|
|
if (newwin == c->v.v2.locmaxwin &&
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
|
|
ssh2_pkt_addbool(pktout, TRUE);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
|
|
/*
|
|
* CHANNEL_FAILURE doesn't come with any indication of
|
|
* what message caused it, so we have to keep track of the
|
|
* outstanding CHANNEL_REQUESTs ourselves.
|
|
*/
|
|
wa = snew(struct winadj);
|
|
wa->size = newwin - c->v.v2.locwindow;
|
|
wa->next = NULL;
|
|
if (!c->v.v2.winadj_head)
|
|
c->v.v2.winadj_head = wa;
|
|
else
|
|
c->v.v2.winadj_tail->next = wa;
|
|
c->v.v2.winadj_tail = wa;
|
|
if (c->v.v2.throttle_state != UNTHROTTLED)
|
|
c->v.v2.throttle_state = UNTHROTTLING;
|
|
} else {
|
|
/* Pretend the WINDOW_ADJUST was acked immediately. */
|
|
c->v.v2.remlocwin = newwin;
|
|
c->v.v2.throttle_state = THROTTLED;
|
|
}
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
c->v.v2.locwindow = newwin;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find the channel associated with a message. If there's no channel,
|
|
* or it's not properly open, make a noise about it and return NULL.
|
|
*/
|
|
static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
unsigned localid = ssh_pkt_getuint32(pktin);
|
|
struct ssh_channel *c;
|
|
|
|
c = find234(ssh->channels, &localid, ssh_channelfind);
|
|
if (!c ||
|
|
(c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
|
|
pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
|
|
char *buf = dupprintf("Received %s for %s channel %u",
|
|
ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
|
|
pktin->type),
|
|
c ? "half-open" : "nonexistent", localid);
|
|
ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
|
|
sfree(buf);
|
|
return NULL;
|
|
}
|
|
return c;
|
|
}
|
|
|
|
static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/*
|
|
* This should never get called. All channel requests are either
|
|
* sent with want_reply false or are sent before this handler gets
|
|
* installed.
|
|
*/
|
|
struct ssh_channel *c;
|
|
struct winadj *wa;
|
|
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
wa = c->v.v2.winadj_head;
|
|
if (wa)
|
|
ssh_disconnect(ssh, NULL, "Received SSH_MSG_CHANNEL_SUCCESS for "
|
|
"\"winadj@putty.projects.tartarus.org\"",
|
|
SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
|
|
else
|
|
ssh_disconnect(ssh, NULL,
|
|
"Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
|
|
SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
|
|
}
|
|
|
|
static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/*
|
|
* The only time this should get called is for "winadj@putty"
|
|
* messages sent above. All other channel requests are either
|
|
* sent with want_reply false or are sent before this handler gets
|
|
* installed.
|
|
*/
|
|
struct ssh_channel *c;
|
|
struct winadj *wa;
|
|
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
wa = c->v.v2.winadj_head;
|
|
if (!wa) {
|
|
ssh_disconnect(ssh, NULL,
|
|
"Received unsolicited SSH_MSG_CHANNEL_FAILURE",
|
|
SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
|
|
return;
|
|
}
|
|
c->v.v2.winadj_head = wa->next;
|
|
c->v.v2.remlocwin += wa->size;
|
|
sfree(wa);
|
|
/*
|
|
* winadj messages are only sent when the window is fully open, so
|
|
* if we get an ack of one, we know any pending unthrottle is
|
|
* complete.
|
|
*/
|
|
if (c->v.v2.throttle_state == UNTHROTTLING)
|
|
c->v.v2.throttle_state = UNTHROTTLED;
|
|
}
|
|
|
|
static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
struct ssh_channel *c;
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
if (!c->closes) {
|
|
c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
|
|
ssh2_try_send_and_unthrottle(c);
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
char *data;
|
|
int length;
|
|
struct ssh_channel *c;
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
|
|
ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
|
|
return; /* extended but not stderr */
|
|
ssh_pkt_getstring(pktin, &data, &length);
|
|
if (data) {
|
|
int bufsize = 0;
|
|
c->v.v2.locwindow -= length;
|
|
c->v.v2.remlocwin -= length;
|
|
switch (c->type) {
|
|
case CHAN_MAINSESSION:
|
|
bufsize =
|
|
from_backend(ssh->frontend, pktin->type ==
|
|
SSH2_MSG_CHANNEL_EXTENDED_DATA,
|
|
data, length);
|
|
break;
|
|
case CHAN_X11:
|
|
bufsize = x11_send(c->u.x11.s, data, length);
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
bufsize = pfd_send(c->u.pfd.s, data, length);
|
|
break;
|
|
case CHAN_AGENT:
|
|
while (length > 0) {
|
|
if (c->u.a.lensofar < 4) {
|
|
unsigned int l = min(4 - c->u.a.lensofar,
|
|
(unsigned)length);
|
|
memcpy(c->u.a.msglen + c->u.a.lensofar,
|
|
data, l);
|
|
data += l;
|
|
length -= l;
|
|
c->u.a.lensofar += l;
|
|
}
|
|
if (c->u.a.lensofar == 4) {
|
|
c->u.a.totallen =
|
|
4 + GET_32BIT(c->u.a.msglen);
|
|
c->u.a.message = snewn(c->u.a.totallen,
|
|
unsigned char);
|
|
memcpy(c->u.a.message, c->u.a.msglen, 4);
|
|
}
|
|
if (c->u.a.lensofar >= 4 && length > 0) {
|
|
unsigned int l =
|
|
min(c->u.a.totallen - c->u.a.lensofar,
|
|
(unsigned)length);
|
|
memcpy(c->u.a.message + c->u.a.lensofar,
|
|
data, l);
|
|
data += l;
|
|
length -= l;
|
|
c->u.a.lensofar += l;
|
|
}
|
|
if (c->u.a.lensofar == c->u.a.totallen) {
|
|
void *reply;
|
|
int replylen;
|
|
if (agent_query(c->u.a.message,
|
|
c->u.a.totallen,
|
|
&reply, &replylen,
|
|
ssh_agentf_callback, c))
|
|
ssh_agentf_callback(c, reply, replylen);
|
|
sfree(c->u.a.message);
|
|
c->u.a.lensofar = 0;
|
|
}
|
|
}
|
|
bufsize = 0;
|
|
break;
|
|
}
|
|
/*
|
|
* If it looks like the remote end hit the end of its window,
|
|
* and we didn't want it to do that, think about using a
|
|
* larger window.
|
|
*/
|
|
if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
|
|
c->v.v2.locmaxwin < 0x40000000)
|
|
c->v.v2.locmaxwin += OUR_V2_WINSIZE;
|
|
/*
|
|
* If we are not buffering too much data,
|
|
* enlarge the window again at the remote side.
|
|
* If we are buffering too much, we may still
|
|
* need to adjust the window if the server's
|
|
* sent excess data.
|
|
*/
|
|
ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
|
|
c->v.v2.locmaxwin - bufsize : 0);
|
|
/*
|
|
* If we're either buffering way too much data, or if we're
|
|
* buffering anything at all and we're in "simple" mode,
|
|
* throttle the whole channel.
|
|
*/
|
|
if ((bufsize > c->v.v2.locmaxwin ||
|
|
(ssh->cfg.ssh_simple && bufsize > 0)) &&
|
|
!c->throttling_conn) {
|
|
c->throttling_conn = 1;
|
|
ssh_throttle_conn(ssh, +1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
struct ssh_channel *c;
|
|
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
|
|
if (c->type == CHAN_X11) {
|
|
/*
|
|
* Remote EOF on an X11 channel means we should
|
|
* wrap up and close the channel ourselves.
|
|
*/
|
|
x11_close(c->u.x11.s);
|
|
sshfwd_close(c);
|
|
} else if (c->type == CHAN_AGENT) {
|
|
sshfwd_close(c);
|
|
} else if (c->type == CHAN_SOCKDATA) {
|
|
pfd_close(c->u.pfd.s);
|
|
sshfwd_close(c);
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
struct ssh_channel *c;
|
|
struct Packet *pktout;
|
|
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
/* Do pre-close processing on the channel. */
|
|
switch (c->type) {
|
|
case CHAN_MAINSESSION:
|
|
ssh->mainchan = NULL;
|
|
update_specials_menu(ssh->frontend);
|
|
break;
|
|
case CHAN_X11:
|
|
if (c->u.x11.s != NULL)
|
|
x11_close(c->u.x11.s);
|
|
sshfwd_close(c);
|
|
break;
|
|
case CHAN_AGENT:
|
|
sshfwd_close(c);
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
if (c->u.pfd.s != NULL)
|
|
pfd_close(c->u.pfd.s);
|
|
sshfwd_close(c);
|
|
break;
|
|
}
|
|
if (c->closes == 0) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
del234(ssh->channels, c);
|
|
bufchain_clear(&c->v.v2.outbuffer);
|
|
sfree(c);
|
|
|
|
/*
|
|
* See if that was the last channel left open.
|
|
* (This is only our termination condition if we're
|
|
* not running in -N mode.)
|
|
*/
|
|
if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
|
|
/*
|
|
* We used to send SSH_MSG_DISCONNECT here,
|
|
* because I'd believed that _every_ conforming
|
|
* SSH-2 connection had to end with a disconnect
|
|
* being sent by at least one side; apparently
|
|
* I was wrong and it's perfectly OK to
|
|
* unceremoniously slam the connection shut
|
|
* when you're done, and indeed OpenSSH feels
|
|
* this is more polite than sending a
|
|
* DISCONNECT. So now we don't.
|
|
*/
|
|
ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
struct ssh_channel *c;
|
|
struct Packet *pktout;
|
|
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
if (c->type != CHAN_SOCKDATA_DORMANT)
|
|
return; /* dunno why they're confirming this */
|
|
c->remoteid = ssh_pkt_getuint32(pktin);
|
|
c->halfopen = FALSE;
|
|
c->type = CHAN_SOCKDATA;
|
|
c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
|
|
c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
|
|
if (c->u.pfd.s)
|
|
pfd_confirm(c->u.pfd.s);
|
|
if (c->closes) {
|
|
/*
|
|
* We have a pending close on this channel,
|
|
* which we decided on before the server acked
|
|
* the channel open. So now we know the
|
|
* remoteid, we can close it again.
|
|
*/
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
static const char *const reasons[] = {
|
|
"<unknown reason code>",
|
|
"Administratively prohibited",
|
|
"Connect failed",
|
|
"Unknown channel type",
|
|
"Resource shortage",
|
|
};
|
|
unsigned reason_code;
|
|
char *reason_string;
|
|
int reason_length;
|
|
struct ssh_channel *c;
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
if (c->type != CHAN_SOCKDATA_DORMANT)
|
|
return; /* dunno why they're failing this */
|
|
|
|
reason_code = ssh_pkt_getuint32(pktin);
|
|
if (reason_code >= lenof(reasons))
|
|
reason_code = 0; /* ensure reasons[reason_code] in range */
|
|
ssh_pkt_getstring(pktin, &reason_string, &reason_length);
|
|
logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
|
|
reasons[reason_code], reason_length, reason_string);
|
|
|
|
pfd_close(c->u.pfd.s);
|
|
|
|
del234(ssh->channels, c);
|
|
sfree(c);
|
|
}
|
|
|
|
static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
char *type;
|
|
int typelen, want_reply;
|
|
int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
|
|
struct ssh_channel *c;
|
|
struct Packet *pktout;
|
|
|
|
c = ssh2_channel_msg(ssh, pktin);
|
|
if (!c)
|
|
return;
|
|
ssh_pkt_getstring(pktin, &type, &typelen);
|
|
want_reply = ssh2_pkt_getbool(pktin);
|
|
|
|
/*
|
|
* Having got the channel number, we now look at
|
|
* the request type string to see if it's something
|
|
* we recognise.
|
|
*/
|
|
if (c == ssh->mainchan) {
|
|
/*
|
|
* We recognise "exit-status" and "exit-signal" on
|
|
* the primary channel.
|
|
*/
|
|
if (typelen == 11 &&
|
|
!memcmp(type, "exit-status", 11)) {
|
|
|
|
ssh->exitcode = ssh_pkt_getuint32(pktin);
|
|
logeventf(ssh, "Server sent command exit status %d",
|
|
ssh->exitcode);
|
|
reply = SSH2_MSG_CHANNEL_SUCCESS;
|
|
|
|
} else if (typelen == 11 &&
|
|
!memcmp(type, "exit-signal", 11)) {
|
|
|
|
int is_plausible = TRUE, is_int = FALSE;
|
|
char *fmt_sig = "", *fmt_msg = "";
|
|
char *msg;
|
|
int msglen = 0, core = FALSE;
|
|
/* ICK: older versions of OpenSSH (e.g. 3.4p1)
|
|
* provide an `int' for the signal, despite its
|
|
* having been a `string' in the drafts of RFC 4254 since at
|
|
* least 2001. (Fixed in session.c 1.147.) Try to
|
|
* infer which we can safely parse it as. */
|
|
{
|
|
unsigned char *p = pktin->body +
|
|
pktin->savedpos;
|
|
long len = pktin->length - pktin->savedpos;
|
|
unsigned long num = GET_32BIT(p); /* what is it? */
|
|
/* If it's 0, it hardly matters; assume string */
|
|
if (num == 0) {
|
|
is_int = FALSE;
|
|
} else {
|
|
int maybe_int = FALSE, maybe_str = FALSE;
|
|
#define CHECK_HYPOTHESIS(offset, result) \
|
|
do { \
|
|
long q = offset; \
|
|
if (q >= 0 && q+4 <= len) { \
|
|
q = q + 4 + GET_32BIT(p+q); \
|
|
if (q >= 0 && q+4 <= len && \
|
|
((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
|
|
result = TRUE; \
|
|
} \
|
|
} while(0)
|
|
CHECK_HYPOTHESIS(4+1, maybe_int);
|
|
CHECK_HYPOTHESIS(4+num+1, maybe_str);
|
|
#undef CHECK_HYPOTHESIS
|
|
if (maybe_int && !maybe_str)
|
|
is_int = TRUE;
|
|
else if (!maybe_int && maybe_str)
|
|
is_int = FALSE;
|
|
else
|
|
/* Crikey. Either or neither. Panic. */
|
|
is_plausible = FALSE;
|
|
}
|
|
}
|
|
ssh->exitcode = 128; /* means `unknown signal' */
|
|
if (is_plausible) {
|
|
if (is_int) {
|
|
/* Old non-standard OpenSSH. */
|
|
int signum = ssh_pkt_getuint32(pktin);
|
|
fmt_sig = dupprintf(" %d", signum);
|
|
ssh->exitcode = 128 + signum;
|
|
} else {
|
|
/* As per RFC 4254. */
|
|
char *sig;
|
|
int siglen;
|
|
ssh_pkt_getstring(pktin, &sig, &siglen);
|
|
/* Signal name isn't supposed to be blank, but
|
|
* let's cope gracefully if it is. */
|
|
if (siglen) {
|
|
fmt_sig = dupprintf(" \"%.*s\"",
|
|
siglen, sig);
|
|
}
|
|
|
|
/*
|
|
* Really hideous method of translating the
|
|
* signal description back into a locally
|
|
* meaningful number.
|
|
*/
|
|
|
|
if (0)
|
|
;
|
|
#define TRANSLATE_SIGNAL(s) \
|
|
else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
|
|
ssh->exitcode = 128 + SIG ## s
|
|
#ifdef SIGABRT
|
|
TRANSLATE_SIGNAL(ABRT);
|
|
#endif
|
|
#ifdef SIGALRM
|
|
TRANSLATE_SIGNAL(ALRM);
|
|
#endif
|
|
#ifdef SIGFPE
|
|
TRANSLATE_SIGNAL(FPE);
|
|
#endif
|
|
#ifdef SIGHUP
|
|
TRANSLATE_SIGNAL(HUP);
|
|
#endif
|
|
#ifdef SIGILL
|
|
TRANSLATE_SIGNAL(ILL);
|
|
#endif
|
|
#ifdef SIGINT
|
|
TRANSLATE_SIGNAL(INT);
|
|
#endif
|
|
#ifdef SIGKILL
|
|
TRANSLATE_SIGNAL(KILL);
|
|
#endif
|
|
#ifdef SIGPIPE
|
|
TRANSLATE_SIGNAL(PIPE);
|
|
#endif
|
|
#ifdef SIGQUIT
|
|
TRANSLATE_SIGNAL(QUIT);
|
|
#endif
|
|
#ifdef SIGSEGV
|
|
TRANSLATE_SIGNAL(SEGV);
|
|
#endif
|
|
#ifdef SIGTERM
|
|
TRANSLATE_SIGNAL(TERM);
|
|
#endif
|
|
#ifdef SIGUSR1
|
|
TRANSLATE_SIGNAL(USR1);
|
|
#endif
|
|
#ifdef SIGUSR2
|
|
TRANSLATE_SIGNAL(USR2);
|
|
#endif
|
|
#undef TRANSLATE_SIGNAL
|
|
else
|
|
ssh->exitcode = 128;
|
|
}
|
|
core = ssh2_pkt_getbool(pktin);
|
|
ssh_pkt_getstring(pktin, &msg, &msglen);
|
|
if (msglen) {
|
|
fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
|
|
}
|
|
/* ignore lang tag */
|
|
} /* else don't attempt to parse */
|
|
logeventf(ssh, "Server exited on signal%s%s%s",
|
|
fmt_sig, core ? " (core dumped)" : "",
|
|
fmt_msg);
|
|
if (*fmt_sig) sfree(fmt_sig);
|
|
if (*fmt_msg) sfree(fmt_msg);
|
|
reply = SSH2_MSG_CHANNEL_SUCCESS;
|
|
|
|
}
|
|
} else {
|
|
/*
|
|
* This is a channel request we don't know
|
|
* about, so we now either ignore the request
|
|
* or respond with CHANNEL_FAILURE, depending
|
|
* on want_reply.
|
|
*/
|
|
reply = SSH2_MSG_CHANNEL_FAILURE;
|
|
}
|
|
if (want_reply) {
|
|
pktout = ssh2_pkt_init(reply);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
char *type;
|
|
int typelen, want_reply;
|
|
struct Packet *pktout;
|
|
|
|
ssh_pkt_getstring(pktin, &type, &typelen);
|
|
want_reply = ssh2_pkt_getbool(pktin);
|
|
|
|
/*
|
|
* We currently don't support any global requests
|
|
* at all, so we either ignore the request or
|
|
* respond with REQUEST_FAILURE, depending on
|
|
* want_reply.
|
|
*/
|
|
if (want_reply) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
|
|
static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
char *type;
|
|
int typelen;
|
|
char *peeraddr;
|
|
int peeraddrlen;
|
|
int peerport;
|
|
char *error = NULL;
|
|
struct ssh_channel *c;
|
|
unsigned remid, winsize, pktsize;
|
|
struct Packet *pktout;
|
|
|
|
ssh_pkt_getstring(pktin, &type, &typelen);
|
|
c = snew(struct ssh_channel);
|
|
c->ssh = ssh;
|
|
|
|
remid = ssh_pkt_getuint32(pktin);
|
|
winsize = ssh_pkt_getuint32(pktin);
|
|
pktsize = ssh_pkt_getuint32(pktin);
|
|
|
|
if (typelen == 3 && !memcmp(type, "x11", 3)) {
|
|
char *addrstr;
|
|
const char *x11err;
|
|
|
|
ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
|
|
addrstr = snewn(peeraddrlen+1, char);
|
|
memcpy(addrstr, peeraddr, peeraddrlen);
|
|
addrstr[peeraddrlen] = '\0';
|
|
peerport = ssh_pkt_getuint32(pktin);
|
|
|
|
logeventf(ssh, "Received X11 connect request from %s:%d",
|
|
addrstr, peerport);
|
|
|
|
if (!ssh->X11_fwd_enabled)
|
|
error = "X11 forwarding is not enabled";
|
|
else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
|
|
addrstr, peerport, &ssh->cfg)) != NULL) {
|
|
logeventf(ssh, "Local X11 connection failed: %s", x11err);
|
|
error = "Unable to open an X11 connection";
|
|
} else {
|
|
logevent("Opening X11 forward connection succeeded");
|
|
c->type = CHAN_X11;
|
|
}
|
|
|
|
sfree(addrstr);
|
|
} else if (typelen == 15 &&
|
|
!memcmp(type, "forwarded-tcpip", 15)) {
|
|
struct ssh_rportfwd pf, *realpf;
|
|
char *dummy;
|
|
int dummylen;
|
|
ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
|
|
pf.sport = ssh_pkt_getuint32(pktin);
|
|
ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
|
|
peerport = ssh_pkt_getuint32(pktin);
|
|
realpf = find234(ssh->rportfwds, &pf, NULL);
|
|
logeventf(ssh, "Received remote port %d open request "
|
|
"from %s:%d", pf.sport, peeraddr, peerport);
|
|
if (realpf == NULL) {
|
|
error = "Remote port is not recognised";
|
|
} else {
|
|
const char *e = pfd_newconnect(&c->u.pfd.s,
|
|
realpf->dhost,
|
|
realpf->dport, c,
|
|
&ssh->cfg,
|
|
realpf->pfrec->addressfamily);
|
|
logeventf(ssh, "Attempting to forward remote port to "
|
|
"%s:%d", realpf->dhost, realpf->dport);
|
|
if (e != NULL) {
|
|
logeventf(ssh, "Port open failed: %s", e);
|
|
error = "Port open failed";
|
|
} else {
|
|
logevent("Forwarded port opened successfully");
|
|
c->type = CHAN_SOCKDATA;
|
|
}
|
|
}
|
|
} else if (typelen == 22 &&
|
|
!memcmp(type, "auth-agent@openssh.com", 22)) {
|
|
if (!ssh->agentfwd_enabled)
|
|
error = "Agent forwarding is not enabled";
|
|
else {
|
|
c->type = CHAN_AGENT; /* identify channel type */
|
|
c->u.a.lensofar = 0;
|
|
}
|
|
} else {
|
|
error = "Unsupported channel type requested";
|
|
}
|
|
|
|
c->remoteid = remid;
|
|
c->halfopen = FALSE;
|
|
if (error) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
|
|
ssh2_pkt_addstring(pktout, error);
|
|
ssh2_pkt_addstring(pktout, "en"); /* language tag */
|
|
ssh2_pkt_send(ssh, pktout);
|
|
logeventf(ssh, "Rejected channel open: %s", error);
|
|
sfree(c);
|
|
} else {
|
|
ssh2_channel_init(c);
|
|
c->v.v2.remwindow = winsize;
|
|
c->v.v2.remmaxpkt = pktsize;
|
|
add234(ssh->channels, c);
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
|
|
ssh2_pkt_adduint32(pktout, c->remoteid);
|
|
ssh2_pkt_adduint32(pktout, c->localid);
|
|
ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
|
|
ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Buffer banner messages for later display at some convenient point.
|
|
*/
|
|
static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* Arbitrary limit to prevent unbounded inflation of buffer */
|
|
if (bufchain_size(&ssh->banner) <= 131072) {
|
|
char *banner = NULL;
|
|
int size = 0;
|
|
ssh_pkt_getstring(pktin, &banner, &size);
|
|
if (banner)
|
|
bufchain_add(&ssh->banner, banner, size);
|
|
}
|
|
}
|
|
|
|
/* Helper function to deal with sending tty modes for "pty-req" */
|
|
static void ssh2_send_ttymode(void *data, char *mode, char *val)
|
|
{
|
|
struct Packet *pktout = (struct Packet *)data;
|
|
int i = 0;
|
|
unsigned int arg = 0;
|
|
while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
|
|
if (i == lenof(ssh_ttymodes)) return;
|
|
switch (ssh_ttymodes[i].type) {
|
|
case TTY_OP_CHAR:
|
|
arg = ssh_tty_parse_specchar(val);
|
|
break;
|
|
case TTY_OP_BOOL:
|
|
arg = ssh_tty_parse_boolean(val);
|
|
break;
|
|
}
|
|
ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
|
|
ssh2_pkt_adduint32(pktout, arg);
|
|
}
|
|
|
|
/*
|
|
* Handle the SSH-2 userauth and connection layers.
|
|
*/
|
|
static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
|
|
struct Packet *pktin)
|
|
{
|
|
struct do_ssh2_authconn_state {
|
|
enum {
|
|
AUTH_TYPE_NONE,
|
|
AUTH_TYPE_PUBLICKEY,
|
|
AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
|
|
AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
|
|
AUTH_TYPE_PASSWORD,
|
|
AUTH_TYPE_GSSAPI,
|
|
AUTH_TYPE_KEYBOARD_INTERACTIVE,
|
|
AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
|
|
} type;
|
|
int done_service_req;
|
|
int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
|
|
int tried_pubkey_config, done_agent;
|
|
#ifndef NO_GSSAPI
|
|
int can_gssapi;
|
|
int tried_gssapi;
|
|
#endif
|
|
int kbd_inter_refused;
|
|
int we_are_in;
|
|
prompts_t *cur_prompt;
|
|
int num_prompts;
|
|
char username[100];
|
|
char *password;
|
|
int got_username;
|
|
void *publickey_blob;
|
|
int publickey_bloblen;
|
|
int publickey_encrypted;
|
|
char *publickey_algorithm;
|
|
char *publickey_comment;
|
|
unsigned char agent_request[5], *agent_response, *agentp;
|
|
int agent_responselen;
|
|
unsigned char *pkblob_in_agent;
|
|
int keyi, nkeys;
|
|
char *pkblob, *alg, *commentp;
|
|
int pklen, alglen, commentlen;
|
|
int siglen, retlen, len;
|
|
char *q, *agentreq, *ret;
|
|
int try_send;
|
|
int num_env, env_left, env_ok;
|
|
struct Packet *pktout;
|
|
#ifndef NO_GSSAPI
|
|
Ssh_gss_ctx gss_ctx;
|
|
Ssh_gss_buf gss_buf;
|
|
Ssh_gss_buf gss_rcvtok, gss_sndtok;
|
|
Ssh_gss_name gss_srv_name;
|
|
Ssh_gss_stat gss_stat;
|
|
#endif
|
|
};
|
|
crState(do_ssh2_authconn_state);
|
|
|
|
crBegin(ssh->do_ssh2_authconn_crstate);
|
|
|
|
s->done_service_req = FALSE;
|
|
s->we_are_in = FALSE;
|
|
#ifndef NO_GSSAPI
|
|
s->tried_gssapi = FALSE;
|
|
#endif
|
|
|
|
if (!ssh->cfg.ssh_no_userauth) {
|
|
/*
|
|
* Request userauth protocol, and await a response to it.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-userauth");
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
|
|
s->done_service_req = TRUE;
|
|
}
|
|
if (!s->done_service_req) {
|
|
/*
|
|
* Request connection protocol directly, without authentication.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
|
|
s->we_are_in = TRUE; /* no auth required */
|
|
} else {
|
|
bombout(("Server refused service request"));
|
|
crStopV;
|
|
}
|
|
}
|
|
|
|
/* Arrange to be able to deal with any BANNERs that come in.
|
|
* (We do this now as packets may come in during the next bit.) */
|
|
bufchain_init(&ssh->banner);
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
|
|
ssh2_msg_userauth_banner;
|
|
|
|
/*
|
|
* Misc one-time setup for authentication.
|
|
*/
|
|
s->publickey_blob = NULL;
|
|
if (!s->we_are_in) {
|
|
|
|
/*
|
|
* Load the public half of any configured public key file
|
|
* for later use.
|
|
*/
|
|
if (!filename_is_null(ssh->cfg.keyfile)) {
|
|
int keytype;
|
|
logeventf(ssh, "Reading private key file \"%.150s\"",
|
|
filename_to_str(&ssh->cfg.keyfile));
|
|
keytype = key_type(&ssh->cfg.keyfile);
|
|
if (keytype == SSH_KEYTYPE_SSH2) {
|
|
const char *error;
|
|
s->publickey_blob =
|
|
ssh2_userkey_loadpub(&ssh->cfg.keyfile,
|
|
&s->publickey_algorithm,
|
|
&s->publickey_bloblen,
|
|
&s->publickey_comment, &error);
|
|
if (s->publickey_blob) {
|
|
s->publickey_encrypted =
|
|
ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
|
|
} else {
|
|
char *msgbuf;
|
|
logeventf(ssh, "Unable to load private key (%s)",
|
|
error);
|
|
msgbuf = dupprintf("Unable to load private key file "
|
|
"\"%.150s\" (%s)\r\n",
|
|
filename_to_str(&ssh->cfg.keyfile),
|
|
error);
|
|
c_write_str(ssh, msgbuf);
|
|
sfree(msgbuf);
|
|
}
|
|
} else {
|
|
char *msgbuf;
|
|
logeventf(ssh, "Unable to use this key file (%s)",
|
|
key_type_to_str(keytype));
|
|
msgbuf = dupprintf("Unable to use key file \"%.150s\""
|
|
" (%s)\r\n",
|
|
filename_to_str(&ssh->cfg.keyfile),
|
|
key_type_to_str(keytype));
|
|
c_write_str(ssh, msgbuf);
|
|
sfree(msgbuf);
|
|
s->publickey_blob = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find out about any keys Pageant has (but if there's a
|
|
* public key configured, filter out all others).
|
|
*/
|
|
s->nkeys = 0;
|
|
s->agent_response = NULL;
|
|
s->pkblob_in_agent = NULL;
|
|
if (ssh->cfg.tryagent && agent_exists()) {
|
|
|
|
void *r;
|
|
|
|
logevent("Pageant is running. Requesting keys.");
|
|
|
|
/* Request the keys held by the agent. */
|
|
PUT_32BIT(s->agent_request, 1);
|
|
s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
|
|
if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
|
|
ssh_agent_callback, ssh)) {
|
|
do {
|
|
crReturnV;
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server while"
|
|
" waiting for agent response"));
|
|
crStopV;
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
r = ssh->agent_response;
|
|
s->agent_responselen = ssh->agent_response_len;
|
|
}
|
|
s->agent_response = (unsigned char *) r;
|
|
if (s->agent_response && s->agent_responselen >= 5 &&
|
|
s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
|
|
int keyi;
|
|
unsigned char *p;
|
|
p = s->agent_response + 5;
|
|
s->nkeys = GET_32BIT(p);
|
|
p += 4;
|
|
logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
|
|
if (s->publickey_blob) {
|
|
/* See if configured key is in agent. */
|
|
for (keyi = 0; keyi < s->nkeys; keyi++) {
|
|
s->pklen = GET_32BIT(p);
|
|
if (s->pklen == s->publickey_bloblen &&
|
|
!memcmp(p+4, s->publickey_blob,
|
|
s->publickey_bloblen)) {
|
|
logeventf(ssh, "Pageant key #%d matches "
|
|
"configured key file", keyi);
|
|
s->keyi = keyi;
|
|
s->pkblob_in_agent = p;
|
|
break;
|
|
}
|
|
p += 4 + s->pklen;
|
|
p += GET_32BIT(p) + 4; /* comment */
|
|
}
|
|
if (!s->pkblob_in_agent) {
|
|
logevent("Configured key file not in Pageant");
|
|
s->nkeys = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
/*
|
|
* We repeat this whole loop, including the username prompt,
|
|
* until we manage a successful authentication. If the user
|
|
* types the wrong _password_, they can be sent back to the
|
|
* beginning to try another username, if this is configured on.
|
|
* (If they specify a username in the config, they are never
|
|
* asked, even if they do give a wrong password.)
|
|
*
|
|
* I think this best serves the needs of
|
|
*
|
|
* - the people who have no configuration, no keys, and just
|
|
* want to try repeated (username,password) pairs until they
|
|
* type both correctly
|
|
*
|
|
* - people who have keys and configuration but occasionally
|
|
* need to fall back to passwords
|
|
*
|
|
* - people with a key held in Pageant, who might not have
|
|
* logged in to a particular machine before; so they want to
|
|
* type a username, and then _either_ their key will be
|
|
* accepted, _or_ they will type a password. If they mistype
|
|
* the username they will want to be able to get back and
|
|
* retype it!
|
|
*/
|
|
s->username[0] = '\0';
|
|
s->got_username = FALSE;
|
|
while (!s->we_are_in) {
|
|
/*
|
|
* Get a username.
|
|
*/
|
|
if (s->got_username && !ssh->cfg.change_username) {
|
|
/*
|
|
* We got a username last time round this loop, and
|
|
* with change_username turned off we don't try to get
|
|
* it again.
|
|
*/
|
|
} else if (!get_remote_username(&ssh->cfg, s->username,
|
|
sizeof(s->username))) {
|
|
int ret; /* need not be kept over crReturn */
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("SSH login name");
|
|
add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
|
|
lenof(s->username));
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntilV(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* get_userpass_input() failed to get a username.
|
|
* Terminate.
|
|
*/
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
|
|
crStopV;
|
|
}
|
|
memcpy(s->username, s->cur_prompt->prompts[0]->result,
|
|
lenof(s->username));
|
|
free_prompts(s->cur_prompt);
|
|
} else {
|
|
char *stuff;
|
|
if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
|
|
stuff = dupprintf("Using username \"%s\".\r\n", s->username);
|
|
c_write_str(ssh, stuff);
|
|
sfree(stuff);
|
|
}
|
|
}
|
|
s->got_username = TRUE;
|
|
|
|
/*
|
|
* Send an authentication request using method "none": (a)
|
|
* just in case it succeeds, and (b) so that we know what
|
|
* authentication methods we can usefully try next.
|
|
*/
|
|
ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
|
|
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "none"); /* method */
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
s->type = AUTH_TYPE_NONE;
|
|
s->gotit = FALSE;
|
|
s->we_are_in = FALSE;
|
|
|
|
s->tried_pubkey_config = FALSE;
|
|
s->kbd_inter_refused = FALSE;
|
|
|
|
/* Reset agent request state. */
|
|
s->done_agent = FALSE;
|
|
if (s->agent_response) {
|
|
if (s->pkblob_in_agent) {
|
|
s->agentp = s->pkblob_in_agent;
|
|
} else {
|
|
s->agentp = s->agent_response + 5 + 4;
|
|
s->keyi = 0;
|
|
}
|
|
}
|
|
|
|
while (1) {
|
|
/*
|
|
* Wait for the result of the last authentication request.
|
|
*/
|
|
if (!s->gotit)
|
|
crWaitUntilV(pktin);
|
|
/*
|
|
* Now is a convenient point to spew any banner material
|
|
* that we've accumulated. (This should ensure that when
|
|
* we exit the auth loop, we haven't any left to deal
|
|
* with.)
|
|
*/
|
|
{
|
|
int size = bufchain_size(&ssh->banner);
|
|
/*
|
|
* Don't show the banner if we're operating in
|
|
* non-verbose non-interactive mode. (It's probably
|
|
* a script, which means nobody will read the
|
|
* banner _anyway_, and moreover the printing of
|
|
* the banner will screw up processing on the
|
|
* output of (say) plink.)
|
|
*/
|
|
if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
|
|
char *banner = snewn(size, char);
|
|
bufchain_fetch(&ssh->banner, banner, size);
|
|
c_write_untrusted(ssh, banner, size);
|
|
sfree(banner);
|
|
}
|
|
bufchain_clear(&ssh->banner);
|
|
}
|
|
if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
|
|
logevent("Access granted");
|
|
s->we_are_in = TRUE;
|
|
break;
|
|
}
|
|
|
|
if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
|
|
bombout(("Strange packet received during authentication: "
|
|
"type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
|
|
s->gotit = FALSE;
|
|
|
|
/*
|
|
* OK, we're now sitting on a USERAUTH_FAILURE message, so
|
|
* we can look at the string in it and know what we can
|
|
* helpfully try next.
|
|
*/
|
|
if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
|
|
char *methods;
|
|
int methlen;
|
|
ssh_pkt_getstring(pktin, &methods, &methlen);
|
|
if (!ssh2_pkt_getbool(pktin)) {
|
|
/*
|
|
* We have received an unequivocal Access
|
|
* Denied. This can translate to a variety of
|
|
* messages:
|
|
*
|
|
* - if we'd just tried "none" authentication,
|
|
* it's not worth printing anything at all
|
|
*
|
|
* - if we'd just tried a public key _offer_,
|
|
* the message should be "Server refused our
|
|
* key" (or no message at all if the key
|
|
* came from Pageant)
|
|
*
|
|
* - if we'd just tried anything else, the
|
|
* message really should be "Access denied".
|
|
*
|
|
* Additionally, if we'd just tried password
|
|
* authentication, we should break out of this
|
|
* whole loop so as to go back to the username
|
|
* prompt (iff we're configured to allow
|
|
* username change attempts).
|
|
*/
|
|
if (s->type == AUTH_TYPE_NONE) {
|
|
/* do nothing */
|
|
} else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
|
|
s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
|
|
if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
|
|
c_write_str(ssh, "Server refused our key\r\n");
|
|
logevent("Server refused public key");
|
|
} else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
|
|
/* server declined keyboard-interactive; ignore */
|
|
} else {
|
|
c_write_str(ssh, "Access denied\r\n");
|
|
logevent("Access denied");
|
|
if (s->type == AUTH_TYPE_PASSWORD &&
|
|
ssh->cfg.change_username) {
|
|
/* XXX perhaps we should allow
|
|
* keyboard-interactive to do this too? */
|
|
s->we_are_in = FALSE;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
c_write_str(ssh, "Further authentication required\r\n");
|
|
logevent("Further authentication required");
|
|
}
|
|
|
|
s->can_pubkey =
|
|
in_commasep_string("publickey", methods, methlen);
|
|
s->can_passwd =
|
|
in_commasep_string("password", methods, methlen);
|
|
s->can_keyb_inter = ssh->cfg.try_ki_auth &&
|
|
in_commasep_string("keyboard-interactive", methods, methlen);
|
|
#ifndef NO_GSSAPI
|
|
s->can_gssapi = ssh->cfg.try_gssapi_auth &&
|
|
in_commasep_string("gssapi-with-mic", methods, methlen) &&
|
|
ssh_gss_init();
|
|
#endif
|
|
}
|
|
|
|
ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
|
|
|
|
if (s->can_pubkey && !s->done_agent && s->nkeys) {
|
|
|
|
/*
|
|
* Attempt public-key authentication using a key from Pageant.
|
|
*/
|
|
|
|
ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
|
|
|
|
logeventf(ssh, "Trying Pageant key #%d", s->keyi);
|
|
|
|
/* Unpack key from agent response */
|
|
s->pklen = GET_32BIT(s->agentp);
|
|
s->agentp += 4;
|
|
s->pkblob = (char *)s->agentp;
|
|
s->agentp += s->pklen;
|
|
s->alglen = GET_32BIT(s->pkblob);
|
|
s->alg = s->pkblob + 4;
|
|
s->commentlen = GET_32BIT(s->agentp);
|
|
s->agentp += 4;
|
|
s->commentp = (char *)s->agentp;
|
|
s->agentp += s->commentlen;
|
|
/* s->agentp now points at next key, if any */
|
|
|
|
/* See if server will accept it */
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "publickey");
|
|
/* method */
|
|
ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
|
|
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
|
|
|
|
/* Offer of key refused. */
|
|
s->gotit = TRUE;
|
|
|
|
} else {
|
|
|
|
void *vret;
|
|
|
|
if (flags & FLAG_VERBOSE) {
|
|
c_write_str(ssh, "Authenticating with "
|
|
"public key \"");
|
|
c_write(ssh, s->commentp, s->commentlen);
|
|
c_write_str(ssh, "\" from agent\r\n");
|
|
}
|
|
|
|
/*
|
|
* Server is willing to accept the key.
|
|
* Construct a SIGN_REQUEST.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "publickey");
|
|
/* method */
|
|
ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
|
|
|
|
/* Ask agent for signature. */
|
|
s->siglen = s->pktout->length - 5 + 4 +
|
|
ssh->v2_session_id_len;
|
|
if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
|
|
s->siglen -= 4;
|
|
s->len = 1; /* message type */
|
|
s->len += 4 + s->pklen; /* key blob */
|
|
s->len += 4 + s->siglen; /* data to sign */
|
|
s->len += 4; /* flags */
|
|
s->agentreq = snewn(4 + s->len, char);
|
|
PUT_32BIT(s->agentreq, s->len);
|
|
s->q = s->agentreq + 4;
|
|
*s->q++ = SSH2_AGENTC_SIGN_REQUEST;
|
|
PUT_32BIT(s->q, s->pklen);
|
|
s->q += 4;
|
|
memcpy(s->q, s->pkblob, s->pklen);
|
|
s->q += s->pklen;
|
|
PUT_32BIT(s->q, s->siglen);
|
|
s->q += 4;
|
|
/* Now the data to be signed... */
|
|
if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
|
|
PUT_32BIT(s->q, ssh->v2_session_id_len);
|
|
s->q += 4;
|
|
}
|
|
memcpy(s->q, ssh->v2_session_id,
|
|
ssh->v2_session_id_len);
|
|
s->q += ssh->v2_session_id_len;
|
|
memcpy(s->q, s->pktout->data + 5,
|
|
s->pktout->length - 5);
|
|
s->q += s->pktout->length - 5;
|
|
/* And finally the (zero) flags word. */
|
|
PUT_32BIT(s->q, 0);
|
|
if (!agent_query(s->agentreq, s->len + 4,
|
|
&vret, &s->retlen,
|
|
ssh_agent_callback, ssh)) {
|
|
do {
|
|
crReturnV;
|
|
if (pktin) {
|
|
bombout(("Unexpected data from server"
|
|
" while waiting for agent"
|
|
" response"));
|
|
crStopV;
|
|
}
|
|
} while (pktin || inlen > 0);
|
|
vret = ssh->agent_response;
|
|
s->retlen = ssh->agent_response_len;
|
|
}
|
|
s->ret = vret;
|
|
sfree(s->agentreq);
|
|
if (s->ret) {
|
|
if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
|
|
logevent("Sending Pageant's response");
|
|
ssh2_add_sigblob(ssh, s->pktout,
|
|
s->pkblob, s->pklen,
|
|
s->ret + 9,
|
|
GET_32BIT(s->ret + 5));
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
s->type = AUTH_TYPE_PUBLICKEY;
|
|
} else {
|
|
/* FIXME: less drastic response */
|
|
bombout(("Pageant failed to answer challenge"));
|
|
crStopV;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Do we have any keys left to try? */
|
|
if (s->pkblob_in_agent) {
|
|
s->done_agent = TRUE;
|
|
s->tried_pubkey_config = TRUE;
|
|
} else {
|
|
s->keyi++;
|
|
if (s->keyi >= s->nkeys)
|
|
s->done_agent = TRUE;
|
|
}
|
|
|
|
} else if (s->can_pubkey && s->publickey_blob &&
|
|
!s->tried_pubkey_config) {
|
|
|
|
struct ssh2_userkey *key; /* not live over crReturn */
|
|
char *passphrase; /* not live over crReturn */
|
|
|
|
ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
|
|
|
|
s->tried_pubkey_config = TRUE;
|
|
|
|
/*
|
|
* Try the public key supplied in the configuration.
|
|
*
|
|
* First, offer the public blob to see if the server is
|
|
* willing to accept it.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
|
|
ssh2_pkt_addbool(s->pktout, FALSE);
|
|
/* no signature included */
|
|
ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout,
|
|
(char *)s->publickey_blob,
|
|
s->publickey_bloblen);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
logevent("Offered public key");
|
|
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
|
|
/* Key refused. Give up. */
|
|
s->gotit = TRUE; /* reconsider message next loop */
|
|
s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
|
|
continue; /* process this new message */
|
|
}
|
|
logevent("Offer of public key accepted");
|
|
|
|
/*
|
|
* Actually attempt a serious authentication using
|
|
* the key.
|
|
*/
|
|
if (flags & FLAG_VERBOSE) {
|
|
c_write_str(ssh, "Authenticating with public key \"");
|
|
c_write_str(ssh, s->publickey_comment);
|
|
c_write_str(ssh, "\"\r\n");
|
|
}
|
|
key = NULL;
|
|
while (!key) {
|
|
const char *error; /* not live over crReturn */
|
|
if (s->publickey_encrypted) {
|
|
/*
|
|
* Get a passphrase from the user.
|
|
*/
|
|
int ret; /* need not be kept over crReturn */
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = FALSE;
|
|
s->cur_prompt->name = dupstr("SSH key passphrase");
|
|
add_prompt(s->cur_prompt,
|
|
dupprintf("Passphrase for key \"%.100s\": ",
|
|
s->publickey_comment),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntilV(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt,
|
|
in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/* Failed to get a passphrase. Terminate. */
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, NULL,
|
|
"Unable to authenticate",
|
|
SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
|
|
TRUE);
|
|
crStopV;
|
|
}
|
|
passphrase =
|
|
dupstr(s->cur_prompt->prompts[0]->result);
|
|
free_prompts(s->cur_prompt);
|
|
} else {
|
|
passphrase = NULL; /* no passphrase needed */
|
|
}
|
|
|
|
/*
|
|
* Try decrypting the key.
|
|
*/
|
|
key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
|
|
&error);
|
|
if (passphrase) {
|
|
/* burn the evidence */
|
|
memset(passphrase, 0, strlen(passphrase));
|
|
sfree(passphrase);
|
|
}
|
|
if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
|
|
if (passphrase &&
|
|
(key == SSH2_WRONG_PASSPHRASE)) {
|
|
c_write_str(ssh, "Wrong passphrase\r\n");
|
|
key = NULL;
|
|
/* and loop again */
|
|
} else {
|
|
c_write_str(ssh, "Unable to load private key (");
|
|
c_write_str(ssh, error);
|
|
c_write_str(ssh, ")\r\n");
|
|
key = NULL;
|
|
break; /* try something else */
|
|
}
|
|
}
|
|
}
|
|
|
|
if (key) {
|
|
unsigned char *pkblob, *sigblob, *sigdata;
|
|
int pkblob_len, sigblob_len, sigdata_len;
|
|
int p;
|
|
|
|
/*
|
|
* We have loaded the private key and the server
|
|
* has announced that it's willing to accept it.
|
|
* Hallelujah. Generate a signature and send it.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "publickey");
|
|
/* method */
|
|
ssh2_pkt_addbool(s->pktout, TRUE);
|
|
/* signature follows */
|
|
ssh2_pkt_addstring(s->pktout, key->alg->name);
|
|
pkblob = key->alg->public_blob(key->data,
|
|
&pkblob_len);
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
|
|
pkblob_len);
|
|
|
|
/*
|
|
* The data to be signed is:
|
|
*
|
|
* string session-id
|
|
*
|
|
* followed by everything so far placed in the
|
|
* outgoing packet.
|
|
*/
|
|
sigdata_len = s->pktout->length - 5 + 4 +
|
|
ssh->v2_session_id_len;
|
|
if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
|
|
sigdata_len -= 4;
|
|
sigdata = snewn(sigdata_len, unsigned char);
|
|
p = 0;
|
|
if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
|
|
PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
|
|
p += 4;
|
|
}
|
|
memcpy(sigdata+p, ssh->v2_session_id,
|
|
ssh->v2_session_id_len);
|
|
p += ssh->v2_session_id_len;
|
|
memcpy(sigdata+p, s->pktout->data + 5,
|
|
s->pktout->length - 5);
|
|
p += s->pktout->length - 5;
|
|
assert(p == sigdata_len);
|
|
sigblob = key->alg->sign(key->data, (char *)sigdata,
|
|
sigdata_len, &sigblob_len);
|
|
ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
|
|
sigblob, sigblob_len);
|
|
sfree(pkblob);
|
|
sfree(sigblob);
|
|
sfree(sigdata);
|
|
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
s->type = AUTH_TYPE_PUBLICKEY;
|
|
key->alg->freekey(key->data);
|
|
}
|
|
|
|
#ifndef NO_GSSAPI
|
|
} else if (s->can_gssapi && !s->tried_gssapi) {
|
|
|
|
/* GSSAPI Authentication */
|
|
|
|
int micoffset, len;
|
|
char *data;
|
|
Ssh_gss_buf mic;
|
|
s->type = AUTH_TYPE_GSSAPI;
|
|
s->tried_gssapi = TRUE;
|
|
s->gotit = TRUE;
|
|
ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
|
|
|
|
/* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
|
|
|
|
/* add mechanism info */
|
|
ssh_gss_indicate_mech(&s->gss_buf);
|
|
|
|
/* number of GSSAPI mechanisms */
|
|
ssh2_pkt_adduint32(s->pktout,1);
|
|
|
|
/* length of OID + 2 */
|
|
ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
|
|
ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
|
|
|
|
/* length of OID */
|
|
ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
|
|
|
|
ssh_pkt_adddata(s->pktout, s->gss_buf.value,
|
|
s->gss_buf.length);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
|
|
logevent("GSSAPI authentication request refused");
|
|
continue;
|
|
}
|
|
|
|
/* check returned packet ... */
|
|
|
|
ssh_pkt_getstring(pktin, &data, &len);
|
|
s->gss_rcvtok.value = data;
|
|
s->gss_rcvtok.length = len;
|
|
if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
|
|
((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
|
|
((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
|
|
memcmp((char *)s->gss_rcvtok.value + 2,
|
|
s->gss_buf.value,s->gss_buf.length) ) {
|
|
logevent("GSSAPI authentication - wrong response from server");
|
|
continue;
|
|
}
|
|
|
|
/* now start running */
|
|
s->gss_stat = ssh_gss_import_name(ssh->fullhostname,
|
|
&s->gss_srv_name);
|
|
if (s->gss_stat != SSH_GSS_OK) {
|
|
if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
|
|
logevent("GSSAPI import name failed - Bad service name");
|
|
else
|
|
logevent("GSSAPI import name failed");
|
|
continue;
|
|
}
|
|
|
|
/* fetch TGT into GSS engine */
|
|
s->gss_stat = ssh_gss_acquire_cred(&s->gss_ctx);
|
|
|
|
if (s->gss_stat != SSH_GSS_OK) {
|
|
logevent("GSSAPI authentication failed to get credentials");
|
|
ssh_gss_release_name(&s->gss_srv_name);
|
|
continue;
|
|
}
|
|
|
|
/* initial tokens are empty */
|
|
SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
|
|
SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
|
|
|
|
/* now enter the loop */
|
|
do {
|
|
s->gss_stat = ssh_gss_init_sec_context(&s->gss_ctx,
|
|
s->gss_srv_name,
|
|
ssh->cfg.gssapifwd,
|
|
&s->gss_rcvtok,
|
|
&s->gss_sndtok);
|
|
|
|
if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
|
|
s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
|
|
logevent("GSSAPI authentication initialisation failed");
|
|
|
|
if (ssh_gss_display_status(s->gss_ctx,&s->gss_buf) == SSH_GSS_OK) {
|
|
logevent(s->gss_buf.value);
|
|
sfree(s->gss_buf.value);
|
|
}
|
|
|
|
break;
|
|
}
|
|
logevent("GSSAPI authentication initialised");
|
|
|
|
/* Client and server now exchange tokens until GSSAPI
|
|
* no longer says CONTINUE_NEEDED */
|
|
|
|
if (s->gss_sndtok.length != 0) {
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
|
|
ssh_pkt_addstring_start(s->pktout);
|
|
ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
ssh_gss_free_tok(&s->gss_sndtok);
|
|
}
|
|
|
|
if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
|
|
logevent("GSSAPI authentication - bad server response");
|
|
s->gss_stat = SSH_GSS_FAILURE;
|
|
break;
|
|
}
|
|
ssh_pkt_getstring(pktin, &data, &len);
|
|
s->gss_rcvtok.value = data;
|
|
s->gss_rcvtok.length = len;
|
|
}
|
|
} while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
|
|
|
|
if (s->gss_stat != SSH_GSS_OK) {
|
|
ssh_gss_release_name(&s->gss_srv_name);
|
|
ssh_gss_release_cred(&s->gss_ctx);
|
|
continue;
|
|
}
|
|
logevent("GSSAPI authentication loop finished OK");
|
|
|
|
/* Now send the MIC */
|
|
|
|
s->pktout = ssh2_pkt_init(0);
|
|
micoffset = s->pktout->length;
|
|
ssh_pkt_addstring_start(s->pktout);
|
|
ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
|
|
ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh_pkt_addstring(s->pktout, s->username);
|
|
ssh_pkt_addstring(s->pktout, "ssh-connection");
|
|
ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
|
|
|
|
s->gss_buf.value = (char *)s->pktout->data + micoffset;
|
|
s->gss_buf.length = s->pktout->length - micoffset;
|
|
|
|
ssh_gss_get_mic(s->gss_ctx, &s->gss_buf, &mic);
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
|
|
ssh_pkt_addstring_start(s->pktout);
|
|
ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
ssh_gss_free_mic(&mic);
|
|
|
|
s->gotit = FALSE;
|
|
|
|
ssh_gss_release_name(&s->gss_srv_name);
|
|
ssh_gss_release_cred(&s->gss_ctx);
|
|
continue;
|
|
#endif
|
|
} else if (s->can_keyb_inter && !s->kbd_inter_refused) {
|
|
|
|
/*
|
|
* Keyboard-interactive authentication.
|
|
*/
|
|
|
|
s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
|
|
|
|
ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
|
|
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
|
|
/* method */
|
|
ssh2_pkt_addstring(s->pktout, ""); /* lang */
|
|
ssh2_pkt_addstring(s->pktout, ""); /* submethods */
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
|
|
/* Server is not willing to do keyboard-interactive
|
|
* at all (or, bizarrely but legally, accepts the
|
|
* user without actually issuing any prompts).
|
|
* Give up on it entirely. */
|
|
s->gotit = TRUE;
|
|
if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
|
|
logevent("Keyboard-interactive authentication refused");
|
|
s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
|
|
s->kbd_inter_refused = TRUE; /* don't try it again */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Loop while the server continues to send INFO_REQUESTs.
|
|
*/
|
|
while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
|
|
|
|
char *name, *inst, *lang;
|
|
int name_len, inst_len, lang_len;
|
|
int i;
|
|
|
|
/*
|
|
* We've got a fresh USERAUTH_INFO_REQUEST.
|
|
* Get the preamble and start building a prompt.
|
|
*/
|
|
ssh_pkt_getstring(pktin, &name, &name_len);
|
|
ssh_pkt_getstring(pktin, &inst, &inst_len);
|
|
ssh_pkt_getstring(pktin, &lang, &lang_len);
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = TRUE;
|
|
|
|
/*
|
|
* Get any prompt(s) from the packet.
|
|
*/
|
|
s->num_prompts = ssh_pkt_getuint32(pktin);
|
|
for (i = 0; i < s->num_prompts; i++) {
|
|
char *prompt;
|
|
int prompt_len;
|
|
int echo;
|
|
static char noprompt[] =
|
|
"<server failed to send prompt>: ";
|
|
|
|
ssh_pkt_getstring(pktin, &prompt, &prompt_len);
|
|
echo = ssh2_pkt_getbool(pktin);
|
|
if (!prompt_len) {
|
|
prompt = noprompt;
|
|
prompt_len = lenof(noprompt)-1;
|
|
}
|
|
add_prompt(s->cur_prompt,
|
|
dupprintf("%.*s", prompt_len, prompt),
|
|
echo, SSH_MAX_PASSWORD_LEN);
|
|
}
|
|
|
|
if (name_len) {
|
|
/* FIXME: better prefix to distinguish from
|
|
* local prompts? */
|
|
s->cur_prompt->name =
|
|
dupprintf("SSH server: %.*s", name_len, name);
|
|
s->cur_prompt->name_reqd = TRUE;
|
|
} else {
|
|
s->cur_prompt->name =
|
|
dupstr("SSH server authentication");
|
|
s->cur_prompt->name_reqd = FALSE;
|
|
}
|
|
/* We add a prefix to try to make it clear that a prompt
|
|
* has come from the server.
|
|
* FIXME: ugly to print "Using..." in prompt _every_
|
|
* time round. Can this be done more subtly? */
|
|
/* Special case: for reasons best known to themselves,
|
|
* some servers send k-i requests with no prompts and
|
|
* nothing to display. Keep quiet in this case. */
|
|
if (s->num_prompts || name_len || inst_len) {
|
|
s->cur_prompt->instruction =
|
|
dupprintf("Using keyboard-interactive authentication.%s%.*s",
|
|
inst_len ? "\n" : "", inst_len, inst);
|
|
s->cur_prompt->instr_reqd = TRUE;
|
|
} else {
|
|
s->cur_prompt->instr_reqd = FALSE;
|
|
}
|
|
|
|
/*
|
|
* Display any instructions, and get the user's
|
|
* response(s).
|
|
*/
|
|
{
|
|
int ret; /* not live over crReturn */
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntilV(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* Failed to get responses. Terminate.
|
|
*/
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, NULL, "Unable to authenticate",
|
|
SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
|
|
TRUE);
|
|
crStopV;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send the response(s) to the server.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
|
|
ssh2_pkt_adduint32(s->pktout, s->num_prompts);
|
|
for (i=0; i < s->num_prompts; i++) {
|
|
dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
|
|
ssh2_pkt_addstring(s->pktout,
|
|
s->cur_prompt->prompts[i]->result);
|
|
end_log_omission(ssh, s->pktout);
|
|
}
|
|
ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
|
|
|
|
/*
|
|
* Get the next packet in case it's another
|
|
* INFO_REQUEST.
|
|
*/
|
|
crWaitUntilV(pktin);
|
|
|
|
}
|
|
|
|
/*
|
|
* We should have SUCCESS or FAILURE now.
|
|
*/
|
|
s->gotit = TRUE;
|
|
|
|
} else if (s->can_passwd) {
|
|
|
|
/*
|
|
* Plain old password authentication.
|
|
*/
|
|
int ret; /* not live over crReturn */
|
|
int changereq_first_time; /* not live over crReturn */
|
|
|
|
ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
|
|
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("SSH password");
|
|
add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
|
|
s->username,
|
|
ssh->savedhost),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntilV(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* Failed to get responses. Terminate.
|
|
*/
|
|
free_prompts(s->cur_prompt);
|
|
ssh_disconnect(ssh, NULL, "Unable to authenticate",
|
|
SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
|
|
TRUE);
|
|
crStopV;
|
|
}
|
|
/*
|
|
* Squirrel away the password. (We may need it later if
|
|
* asked to change it.)
|
|
*/
|
|
s->password = dupstr(s->cur_prompt->prompts[0]->result);
|
|
free_prompts(s->cur_prompt);
|
|
|
|
/*
|
|
* Send the password packet.
|
|
*
|
|
* We pad out the password packet to 256 bytes to make
|
|
* it harder for an attacker to find the length of the
|
|
* user's password.
|
|
*
|
|
* Anyone using a password longer than 256 bytes
|
|
* probably doesn't have much to worry about from
|
|
* people who find out how long their password is!
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "password");
|
|
ssh2_pkt_addbool(s->pktout, FALSE);
|
|
dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
|
|
ssh2_pkt_addstring(s->pktout, s->password);
|
|
end_log_omission(ssh, s->pktout);
|
|
ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
|
|
logevent("Sent password");
|
|
s->type = AUTH_TYPE_PASSWORD;
|
|
|
|
/*
|
|
* Wait for next packet, in case it's a password change
|
|
* request.
|
|
*/
|
|
crWaitUntilV(pktin);
|
|
changereq_first_time = TRUE;
|
|
|
|
while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
|
|
|
|
/*
|
|
* We're being asked for a new password
|
|
* (perhaps not for the first time).
|
|
* Loop until the server accepts it.
|
|
*/
|
|
|
|
int got_new = FALSE; /* not live over crReturn */
|
|
char *prompt; /* not live over crReturn */
|
|
int prompt_len; /* not live over crReturn */
|
|
|
|
{
|
|
char *msg;
|
|
if (changereq_first_time)
|
|
msg = "Server requested password change";
|
|
else
|
|
msg = "Server rejected new password";
|
|
logevent(msg);
|
|
c_write_str(ssh, msg);
|
|
c_write_str(ssh, "\r\n");
|
|
}
|
|
|
|
ssh_pkt_getstring(pktin, &prompt, &prompt_len);
|
|
|
|
s->cur_prompt = new_prompts(ssh->frontend);
|
|
s->cur_prompt->to_server = TRUE;
|
|
s->cur_prompt->name = dupstr("New SSH password");
|
|
s->cur_prompt->instruction =
|
|
dupprintf("%.*s", prompt_len, prompt);
|
|
s->cur_prompt->instr_reqd = TRUE;
|
|
/*
|
|
* There's no explicit requirement in the protocol
|
|
* for the "old" passwords in the original and
|
|
* password-change messages to be the same, and
|
|
* apparently some Cisco kit supports password change
|
|
* by the user entering a blank password originally
|
|
* and the real password subsequently, so,
|
|
* reluctantly, we prompt for the old password again.
|
|
*
|
|
* (On the other hand, some servers don't even bother
|
|
* to check this field.)
|
|
*/
|
|
add_prompt(s->cur_prompt,
|
|
dupstr("Current password (blank for previously entered password): "),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
add_prompt(s->cur_prompt, dupstr("Enter new password: "),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
|
|
FALSE, SSH_MAX_PASSWORD_LEN);
|
|
|
|
/*
|
|
* Loop until the user manages to enter the same
|
|
* password twice.
|
|
*/
|
|
while (!got_new) {
|
|
|
|
ret = get_userpass_input(s->cur_prompt, NULL, 0);
|
|
while (ret < 0) {
|
|
ssh->send_ok = 1;
|
|
crWaitUntilV(!pktin);
|
|
ret = get_userpass_input(s->cur_prompt, in, inlen);
|
|
ssh->send_ok = 0;
|
|
}
|
|
if (!ret) {
|
|
/*
|
|
* Failed to get responses. Terminate.
|
|
*/
|
|
/* burn the evidence */
|
|
free_prompts(s->cur_prompt);
|
|
memset(s->password, 0, strlen(s->password));
|
|
sfree(s->password);
|
|
ssh_disconnect(ssh, NULL, "Unable to authenticate",
|
|
SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
|
|
TRUE);
|
|
crStopV;
|
|
}
|
|
|
|
/*
|
|
* If the user specified a new original password
|
|
* (IYSWIM), overwrite any previously specified
|
|
* one.
|
|
* (A side effect is that the user doesn't have to
|
|
* re-enter it if they louse up the new password.)
|
|
*/
|
|
if (s->cur_prompt->prompts[0]->result[0]) {
|
|
memset(s->password, 0, strlen(s->password));
|
|
/* burn the evidence */
|
|
sfree(s->password);
|
|
s->password =
|
|
dupstr(s->cur_prompt->prompts[0]->result);
|
|
}
|
|
|
|
/*
|
|
* Check the two new passwords match.
|
|
*/
|
|
got_new = (strcmp(s->cur_prompt->prompts[1]->result,
|
|
s->cur_prompt->prompts[2]->result)
|
|
== 0);
|
|
if (!got_new)
|
|
/* They don't. Silly user. */
|
|
c_write_str(ssh, "Passwords do not match\r\n");
|
|
|
|
}
|
|
|
|
/*
|
|
* Send the new password (along with the old one).
|
|
* (see above for padding rationale)
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(s->pktout, s->username);
|
|
ssh2_pkt_addstring(s->pktout, "ssh-connection");
|
|
/* service requested */
|
|
ssh2_pkt_addstring(s->pktout, "password");
|
|
ssh2_pkt_addbool(s->pktout, TRUE);
|
|
dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
|
|
ssh2_pkt_addstring(s->pktout, s->password);
|
|
ssh2_pkt_addstring(s->pktout,
|
|
s->cur_prompt->prompts[1]->result);
|
|
free_prompts(s->cur_prompt);
|
|
end_log_omission(ssh, s->pktout);
|
|
ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
|
|
logevent("Sent new password");
|
|
|
|
/*
|
|
* Now see what the server has to say about it.
|
|
* (If it's CHANGEREQ again, it's not happy with the
|
|
* new password.)
|
|
*/
|
|
crWaitUntilV(pktin);
|
|
changereq_first_time = FALSE;
|
|
|
|
}
|
|
|
|
/*
|
|
* We need to reexamine the current pktin at the top
|
|
* of the loop. Either:
|
|
* - we weren't asked to change password at all, in
|
|
* which case it's a SUCCESS or FAILURE with the
|
|
* usual meaning
|
|
* - we sent a new password, and the server was
|
|
* either OK with it (SUCCESS or FAILURE w/partial
|
|
* success) or unhappy with the _old_ password
|
|
* (FAILURE w/o partial success)
|
|
* In any of these cases, we go back to the top of
|
|
* the loop and start again.
|
|
*/
|
|
s->gotit = TRUE;
|
|
|
|
/*
|
|
* We don't need the old password any more, in any
|
|
* case. Burn the evidence.
|
|
*/
|
|
memset(s->password, 0, strlen(s->password));
|
|
sfree(s->password);
|
|
|
|
} else {
|
|
|
|
ssh_disconnect(ssh, NULL,
|
|
"No supported authentication methods available",
|
|
SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
|
|
FALSE);
|
|
crStopV;
|
|
|
|
}
|
|
|
|
}
|
|
}
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
|
|
|
|
/* Clear up various bits and pieces from authentication. */
|
|
if (s->publickey_blob) {
|
|
sfree(s->publickey_blob);
|
|
sfree(s->publickey_comment);
|
|
}
|
|
if (s->agent_response)
|
|
sfree(s->agent_response);
|
|
|
|
/*
|
|
* Now the connection protocol has started, one way or another.
|
|
*/
|
|
|
|
ssh->channels = newtree234(ssh_channelcmp);
|
|
|
|
/*
|
|
* Set up handlers for some connection protocol messages, so we
|
|
* don't have to handle them repeatedly in this coroutine.
|
|
*/
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
|
|
ssh2_msg_channel_window_adjust;
|
|
ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
|
|
ssh2_msg_global_request;
|
|
|
|
/*
|
|
* Create the main session channel.
|
|
*/
|
|
if (ssh->cfg.ssh_no_shell) {
|
|
ssh->mainchan = NULL;
|
|
} else if (*ssh->cfg.ssh_nc_host) {
|
|
/*
|
|
* Just start a direct-tcpip channel and use it as the main
|
|
* channel.
|
|
*/
|
|
ssh->mainchan = snew(struct ssh_channel);
|
|
ssh->mainchan->ssh = ssh;
|
|
ssh2_channel_init(ssh->mainchan);
|
|
logeventf(ssh,
|
|
"Opening direct-tcpip channel to %s:%d in place of session",
|
|
ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
|
|
ssh2_pkt_addstring(s->pktout, "direct-tcpip");
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
|
|
ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
|
|
ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
|
|
/*
|
|
* There's nothing meaningful to put in the originator
|
|
* fields, but some servers insist on syntactically correct
|
|
* information.
|
|
*/
|
|
ssh2_pkt_addstring(s->pktout, "0.0.0.0");
|
|
ssh2_pkt_adduint32(s->pktout, 0);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
|
|
bombout(("Server refused to open a direct-tcpip channel"));
|
|
crStopV;
|
|
/* FIXME: error data comes back in FAILURE packet */
|
|
}
|
|
if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
|
|
bombout(("Server's channel confirmation cited wrong channel"));
|
|
crStopV;
|
|
}
|
|
ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
|
|
ssh->mainchan->halfopen = FALSE;
|
|
ssh->mainchan->type = CHAN_MAINSESSION;
|
|
ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
|
|
ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
|
|
add234(ssh->channels, ssh->mainchan);
|
|
update_specials_menu(ssh->frontend);
|
|
logevent("Opened direct-tcpip channel");
|
|
ssh->ncmode = TRUE;
|
|
} else {
|
|
ssh->mainchan = snew(struct ssh_channel);
|
|
ssh->mainchan->ssh = ssh;
|
|
ssh2_channel_init(ssh->mainchan);
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
|
|
ssh2_pkt_addstring(s->pktout, "session");
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
|
|
ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
crWaitUntilV(pktin);
|
|
if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
|
|
bombout(("Server refused to open a session"));
|
|
crStopV;
|
|
/* FIXME: error data comes back in FAILURE packet */
|
|
}
|
|
if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
|
|
bombout(("Server's channel confirmation cited wrong channel"));
|
|
crStopV;
|
|
}
|
|
ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
|
|
ssh->mainchan->halfopen = FALSE;
|
|
ssh->mainchan->type = CHAN_MAINSESSION;
|
|
ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
|
|
ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
|
|
add234(ssh->channels, ssh->mainchan);
|
|
update_specials_menu(ssh->frontend);
|
|
logevent("Opened channel for session");
|
|
ssh->ncmode = FALSE;
|
|
}
|
|
|
|
/*
|
|
* Now we have a channel, make dispatch table entries for
|
|
* general channel-based messages.
|
|
*/
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
|
|
ssh2_msg_channel_data;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
|
|
ssh2_msg_channel_open_confirmation;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
|
|
ssh2_msg_channel_open_failure;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
|
|
ssh2_msg_channel_request;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
|
|
ssh2_msg_channel_open;
|
|
|
|
if (ssh->mainchan && ssh->cfg.ssh_simple) {
|
|
/*
|
|
* This message indicates to the server that we promise
|
|
* not to try to run any other channel in parallel with
|
|
* this one, so it's safe for it to advertise a very large
|
|
* window and leave the flow control to TCP.
|
|
*/
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
|
|
ssh2_pkt_addbool(s->pktout, 0); /* no reply */
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
}
|
|
|
|
/*
|
|
* Potentially enable X11 forwarding.
|
|
*/
|
|
if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward &&
|
|
(ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
|
|
ssh->cfg.x11_auth, &ssh->cfg))) {
|
|
logevent("Requesting X11 forwarding");
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(s->pktout, "x11-req");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
ssh2_pkt_addbool(s->pktout, 0); /* many connections */
|
|
ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
|
|
/*
|
|
* Note that while we blank the X authentication data here, we don't
|
|
* take any special action to blank the start of an X11 channel,
|
|
* so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
|
|
* without having session blanking enabled is likely to leak your
|
|
* cookie into the log.
|
|
*/
|
|
dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
|
|
ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
|
|
end_log_omission(ssh, s->pktout);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
|
|
crWaitUntilV(pktin);
|
|
|
|
if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
|
|
if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
|
|
bombout(("Unexpected response to X11 forwarding request:"
|
|
" packet type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
logevent("X11 forwarding refused");
|
|
} else {
|
|
logevent("X11 forwarding enabled");
|
|
ssh->X11_fwd_enabled = TRUE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Enable port forwardings.
|
|
*/
|
|
ssh_setup_portfwd(ssh, &ssh->cfg);
|
|
|
|
/*
|
|
* Potentially enable agent forwarding.
|
|
*/
|
|
if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
|
|
logevent("Requesting OpenSSH-style agent forwarding");
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
|
|
crWaitUntilV(pktin);
|
|
|
|
if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
|
|
if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
|
|
bombout(("Unexpected response to agent forwarding request:"
|
|
" packet type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
logevent("Agent forwarding refused");
|
|
} else {
|
|
logevent("Agent forwarding enabled");
|
|
ssh->agentfwd_enabled = TRUE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now allocate a pty for the session.
|
|
*/
|
|
if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
|
|
/* Unpick the terminal-speed string. */
|
|
/* XXX perhaps we should allow no speeds to be sent. */
|
|
ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
|
|
sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
|
|
/* Build the pty request. */
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
|
|
ssh2_pkt_addstring(s->pktout, "pty-req");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->term_width);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->term_height);
|
|
ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
|
|
ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
parse_ttymodes(ssh, ssh->cfg.ttymodes,
|
|
ssh2_send_ttymode, (void *)s->pktout);
|
|
ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
|
|
ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
|
|
ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
ssh->state = SSH_STATE_INTERMED;
|
|
|
|
crWaitUntilV(pktin);
|
|
|
|
if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
|
|
if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
|
|
bombout(("Unexpected response to pty request:"
|
|
" packet type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
c_write_str(ssh, "Server refused to allocate pty\r\n");
|
|
ssh->editing = ssh->echoing = 1;
|
|
} else {
|
|
logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
|
|
ssh->ospeed, ssh->ispeed);
|
|
}
|
|
} else {
|
|
ssh->editing = ssh->echoing = 1;
|
|
}
|
|
|
|
/*
|
|
* Send environment variables.
|
|
*
|
|
* Simplest thing here is to send all the requests at once, and
|
|
* then wait for a whole bunch of successes or failures.
|
|
*/
|
|
if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
|
|
char *e = ssh->cfg.environmt;
|
|
char *var, *varend, *val;
|
|
|
|
s->num_env = 0;
|
|
|
|
while (*e) {
|
|
var = e;
|
|
while (*e && *e != '\t') e++;
|
|
varend = e;
|
|
if (*e == '\t') e++;
|
|
val = e;
|
|
while (*e) e++;
|
|
e++;
|
|
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(s->pktout, "env");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
ssh2_pkt_addstring_start(s->pktout);
|
|
ssh2_pkt_addstring_data(s->pktout, var, varend-var);
|
|
ssh2_pkt_addstring(s->pktout, val);
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
|
|
s->num_env++;
|
|
}
|
|
|
|
logeventf(ssh, "Sent %d environment variables", s->num_env);
|
|
|
|
s->env_ok = 0;
|
|
s->env_left = s->num_env;
|
|
|
|
while (s->env_left > 0) {
|
|
crWaitUntilV(pktin);
|
|
|
|
if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
|
|
if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
|
|
bombout(("Unexpected response to environment request:"
|
|
" packet type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
} else {
|
|
s->env_ok++;
|
|
}
|
|
|
|
s->env_left--;
|
|
}
|
|
|
|
if (s->env_ok == s->num_env) {
|
|
logevent("All environment variables successfully set");
|
|
} else if (s->env_ok == 0) {
|
|
logevent("All environment variables refused");
|
|
c_write_str(ssh, "Server refused to set environment variables\r\n");
|
|
} else {
|
|
logeventf(ssh, "%d environment variables refused",
|
|
s->num_env - s->env_ok);
|
|
c_write_str(ssh, "Server refused to set all environment variables\r\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Start a shell or a remote command. We may have to attempt
|
|
* this twice if the config data has provided a second choice
|
|
* of command.
|
|
*/
|
|
if (ssh->mainchan && !ssh->ncmode) while (1) {
|
|
int subsys;
|
|
char *cmd;
|
|
|
|
if (ssh->fallback_cmd) {
|
|
subsys = ssh->cfg.ssh_subsys2;
|
|
cmd = ssh->cfg.remote_cmd_ptr2;
|
|
} else {
|
|
subsys = ssh->cfg.ssh_subsys;
|
|
cmd = ssh->cfg.remote_cmd_ptr;
|
|
if (!cmd) cmd = ssh->cfg.remote_cmd;
|
|
}
|
|
|
|
s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
|
|
if (subsys) {
|
|
ssh2_pkt_addstring(s->pktout, "subsystem");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
ssh2_pkt_addstring(s->pktout, cmd);
|
|
} else if (*cmd) {
|
|
ssh2_pkt_addstring(s->pktout, "exec");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
ssh2_pkt_addstring(s->pktout, cmd);
|
|
} else {
|
|
ssh2_pkt_addstring(s->pktout, "shell");
|
|
ssh2_pkt_addbool(s->pktout, 1); /* want reply */
|
|
}
|
|
ssh2_pkt_send(ssh, s->pktout);
|
|
|
|
crWaitUntilV(pktin);
|
|
|
|
if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
|
|
if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
|
|
bombout(("Unexpected response to shell/command request:"
|
|
" packet type %d", pktin->type));
|
|
crStopV;
|
|
}
|
|
/*
|
|
* We failed to start the command. If this is the
|
|
* fallback command, we really are finished; if it's
|
|
* not, and if the fallback command exists, try falling
|
|
* back to it before complaining.
|
|
*/
|
|
if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
|
|
logevent("Primary command failed; attempting fallback");
|
|
ssh->fallback_cmd = TRUE;
|
|
continue;
|
|
}
|
|
bombout(("Server refused to start a shell/command"));
|
|
crStopV;
|
|
} else {
|
|
logevent("Started a shell/command");
|
|
}
|
|
break;
|
|
}
|
|
|
|
ssh->state = SSH_STATE_SESSION;
|
|
if (ssh->size_needed)
|
|
ssh_size(ssh, ssh->term_width, ssh->term_height);
|
|
if (ssh->eof_needed)
|
|
ssh_special(ssh, TS_EOF);
|
|
|
|
/*
|
|
* All the initial channel requests are done, so install the default
|
|
* failure handler.
|
|
*/
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
|
|
|
|
/*
|
|
* Transfer data!
|
|
*/
|
|
if (ssh->ldisc)
|
|
ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
|
|
if (ssh->mainchan)
|
|
ssh->send_ok = 1;
|
|
while (1) {
|
|
crReturnV;
|
|
s->try_send = FALSE;
|
|
if (pktin) {
|
|
|
|
/*
|
|
* _All_ the connection-layer packets we expect to
|
|
* receive are now handled by the dispatch table.
|
|
* Anything that reaches here must be bogus.
|
|
*/
|
|
|
|
bombout(("Strange packet received: type %d", pktin->type));
|
|
crStopV;
|
|
} else if (ssh->mainchan) {
|
|
/*
|
|
* We have spare data. Add it to the channel buffer.
|
|
*/
|
|
ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
|
|
s->try_send = TRUE;
|
|
}
|
|
if (s->try_send) {
|
|
int i;
|
|
struct ssh_channel *c;
|
|
/*
|
|
* Try to send data on all channels if we can.
|
|
*/
|
|
for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
|
|
ssh2_try_send_and_unthrottle(c);
|
|
}
|
|
}
|
|
|
|
crFinishV;
|
|
}
|
|
|
|
/*
|
|
* Handlers for SSH-2 messages that might arrive at any moment.
|
|
*/
|
|
static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* log reason code in disconnect message */
|
|
char *buf, *msg;
|
|
int reason, msglen;
|
|
|
|
reason = ssh_pkt_getuint32(pktin);
|
|
ssh_pkt_getstring(pktin, &msg, &msglen);
|
|
|
|
if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
|
|
buf = dupprintf("Received disconnect message (%s)",
|
|
ssh2_disconnect_reasons[reason]);
|
|
} else {
|
|
buf = dupprintf("Received disconnect message (unknown"
|
|
" type %d)", reason);
|
|
}
|
|
logevent(buf);
|
|
sfree(buf);
|
|
buf = dupprintf("Disconnection message text: %.*s",
|
|
msglen, msg);
|
|
logevent(buf);
|
|
bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
|
|
reason,
|
|
(reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
|
|
ssh2_disconnect_reasons[reason] : "unknown",
|
|
msglen, msg));
|
|
sfree(buf);
|
|
}
|
|
|
|
static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
/* log the debug message */
|
|
char *msg;
|
|
int msglen;
|
|
int always_display;
|
|
|
|
/* XXX maybe we should actually take notice of this */
|
|
always_display = ssh2_pkt_getbool(pktin);
|
|
ssh_pkt_getstring(pktin, &msg, &msglen);
|
|
|
|
logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
|
|
}
|
|
|
|
static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
|
|
{
|
|
struct Packet *pktout;
|
|
pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
|
|
ssh2_pkt_adduint32(pktout, pktin->sequence);
|
|
/*
|
|
* UNIMPLEMENTED messages MUST appear in the same order as the
|
|
* messages they respond to. Hence, never queue them.
|
|
*/
|
|
ssh2_pkt_send_noqueue(ssh, pktout);
|
|
}
|
|
|
|
/*
|
|
* Handle the top-level SSH-2 protocol.
|
|
*/
|
|
static void ssh2_protocol_setup(Ssh ssh)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Most messages cause SSH2_MSG_UNIMPLEMENTED.
|
|
*/
|
|
for (i = 0; i < 256; i++)
|
|
ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
|
|
|
|
/*
|
|
* Any message we actually understand, we set to NULL so that
|
|
* the coroutines will get it.
|
|
*/
|
|
ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
|
|
/* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
|
|
/* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
|
|
ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
|
|
/* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
|
|
/* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
|
|
ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
|
|
ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
|
|
|
|
/*
|
|
* These special message types we install handlers for.
|
|
*/
|
|
ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
|
|
ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
|
|
ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
|
|
}
|
|
|
|
static void ssh2_timer(void *ctx, long now)
|
|
{
|
|
Ssh ssh = (Ssh)ctx;
|
|
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return;
|
|
|
|
if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
|
|
now - ssh->next_rekey >= 0) {
|
|
do_ssh2_transport(ssh, "timeout", -1, NULL);
|
|
}
|
|
}
|
|
|
|
static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
|
|
struct Packet *pktin)
|
|
{
|
|
unsigned char *in = (unsigned char *)vin;
|
|
if (ssh->state == SSH_STATE_CLOSED)
|
|
return;
|
|
|
|
if (pktin) {
|
|
ssh->incoming_data_size += pktin->encrypted_len;
|
|
if (!ssh->kex_in_progress &&
|
|
ssh->max_data_size != 0 &&
|
|
ssh->incoming_data_size > ssh->max_data_size)
|
|
do_ssh2_transport(ssh, "too much data received", -1, NULL);
|
|
}
|
|
|
|
if (pktin && ssh->packet_dispatch[pktin->type]) {
|
|
ssh->packet_dispatch[pktin->type](ssh, pktin);
|
|
return;
|
|
}
|
|
|
|
if (!ssh->protocol_initial_phase_done ||
|
|
(pktin && pktin->type >= 20 && pktin->type < 50)) {
|
|
if (do_ssh2_transport(ssh, in, inlen, pktin) &&
|
|
!ssh->protocol_initial_phase_done) {
|
|
ssh->protocol_initial_phase_done = TRUE;
|
|
/*
|
|
* Allow authconn to initialise itself.
|
|
*/
|
|
do_ssh2_authconn(ssh, NULL, 0, NULL);
|
|
}
|
|
} else {
|
|
do_ssh2_authconn(ssh, in, inlen, pktin);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Called to set up the connection.
|
|
*
|
|
* Returns an error message, or NULL on success.
|
|
*/
|
|
static const char *ssh_init(void *frontend_handle, void **backend_handle,
|
|
Config *cfg,
|
|
char *host, int port, char **realhost, int nodelay,
|
|
int keepalive)
|
|
{
|
|
const char *p;
|
|
Ssh ssh;
|
|
|
|
ssh = snew(struct ssh_tag);
|
|
ssh->cfg = *cfg; /* STRUCTURE COPY */
|
|
ssh->version = 0; /* when not ready yet */
|
|
ssh->s = NULL;
|
|
ssh->cipher = NULL;
|
|
ssh->v1_cipher_ctx = NULL;
|
|
ssh->crcda_ctx = NULL;
|
|
ssh->cscipher = NULL;
|
|
ssh->cs_cipher_ctx = NULL;
|
|
ssh->sccipher = NULL;
|
|
ssh->sc_cipher_ctx = NULL;
|
|
ssh->csmac = NULL;
|
|
ssh->cs_mac_ctx = NULL;
|
|
ssh->scmac = NULL;
|
|
ssh->sc_mac_ctx = NULL;
|
|
ssh->cscomp = NULL;
|
|
ssh->cs_comp_ctx = NULL;
|
|
ssh->sccomp = NULL;
|
|
ssh->sc_comp_ctx = NULL;
|
|
ssh->kex = NULL;
|
|
ssh->kex_ctx = NULL;
|
|
ssh->hostkey = NULL;
|
|
ssh->exitcode = -1;
|
|
ssh->close_expected = FALSE;
|
|
ssh->clean_exit = FALSE;
|
|
ssh->state = SSH_STATE_PREPACKET;
|
|
ssh->size_needed = FALSE;
|
|
ssh->eof_needed = FALSE;
|
|
ssh->ldisc = NULL;
|
|
ssh->logctx = NULL;
|
|
ssh->deferred_send_data = NULL;
|
|
ssh->deferred_len = 0;
|
|
ssh->deferred_size = 0;
|
|
ssh->fallback_cmd = 0;
|
|
ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
|
|
ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
|
|
ssh->x11disp = NULL;
|
|
ssh->v1_compressing = FALSE;
|
|
ssh->v2_outgoing_sequence = 0;
|
|
ssh->ssh1_rdpkt_crstate = 0;
|
|
ssh->ssh2_rdpkt_crstate = 0;
|
|
ssh->do_ssh_init_crstate = 0;
|
|
ssh->ssh_gotdata_crstate = 0;
|
|
ssh->do_ssh1_connection_crstate = 0;
|
|
ssh->do_ssh1_login_crstate = 0;
|
|
ssh->do_ssh2_transport_crstate = 0;
|
|
ssh->do_ssh2_authconn_crstate = 0;
|
|
ssh->do_ssh_init_state = NULL;
|
|
ssh->do_ssh1_login_state = NULL;
|
|
ssh->do_ssh2_transport_state = NULL;
|
|
ssh->do_ssh2_authconn_state = NULL;
|
|
ssh->v_c = NULL;
|
|
ssh->v_s = NULL;
|
|
ssh->mainchan = NULL;
|
|
ssh->throttled_all = 0;
|
|
ssh->v1_stdout_throttling = 0;
|
|
ssh->queue = NULL;
|
|
ssh->queuelen = ssh->queuesize = 0;
|
|
ssh->queueing = FALSE;
|
|
ssh->qhead = ssh->qtail = NULL;
|
|
ssh->deferred_rekey_reason = NULL;
|
|
bufchain_init(&ssh->queued_incoming_data);
|
|
ssh->frozen = FALSE;
|
|
|
|
*backend_handle = ssh;
|
|
|
|
#ifdef MSCRYPTOAPI
|
|
if (crypto_startup() == 0)
|
|
return "Microsoft high encryption pack not installed!";
|
|
#endif
|
|
|
|
ssh->frontend = frontend_handle;
|
|
ssh->term_width = ssh->cfg.width;
|
|
ssh->term_height = ssh->cfg.height;
|
|
|
|
ssh->channels = NULL;
|
|
ssh->rportfwds = NULL;
|
|
ssh->portfwds = NULL;
|
|
|
|
ssh->send_ok = 0;
|
|
ssh->editing = 0;
|
|
ssh->echoing = 0;
|
|
ssh->conn_throttle_count = 0;
|
|
ssh->overall_bufsize = 0;
|
|
ssh->fallback_cmd = 0;
|
|
|
|
ssh->protocol = NULL;
|
|
|
|
ssh->protocol_initial_phase_done = FALSE;
|
|
|
|
ssh->pinger = NULL;
|
|
|
|
ssh->incoming_data_size = ssh->outgoing_data_size =
|
|
ssh->deferred_data_size = 0L;
|
|
ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
|
|
ssh->kex_in_progress = FALSE;
|
|
|
|
p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
|
|
if (p != NULL)
|
|
return p;
|
|
|
|
random_ref();
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void ssh_free(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
struct ssh_channel *c;
|
|
struct ssh_rportfwd *pf;
|
|
|
|
if (ssh->v1_cipher_ctx)
|
|
ssh->cipher->free_context(ssh->v1_cipher_ctx);
|
|
if (ssh->cs_cipher_ctx)
|
|
ssh->cscipher->free_context(ssh->cs_cipher_ctx);
|
|
if (ssh->sc_cipher_ctx)
|
|
ssh->sccipher->free_context(ssh->sc_cipher_ctx);
|
|
if (ssh->cs_mac_ctx)
|
|
ssh->csmac->free_context(ssh->cs_mac_ctx);
|
|
if (ssh->sc_mac_ctx)
|
|
ssh->scmac->free_context(ssh->sc_mac_ctx);
|
|
if (ssh->cs_comp_ctx) {
|
|
if (ssh->cscomp)
|
|
ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
|
|
else
|
|
zlib_compress_cleanup(ssh->cs_comp_ctx);
|
|
}
|
|
if (ssh->sc_comp_ctx) {
|
|
if (ssh->sccomp)
|
|
ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
|
|
else
|
|
zlib_decompress_cleanup(ssh->sc_comp_ctx);
|
|
}
|
|
if (ssh->kex_ctx)
|
|
dh_cleanup(ssh->kex_ctx);
|
|
sfree(ssh->savedhost);
|
|
|
|
while (ssh->queuelen-- > 0)
|
|
ssh_free_packet(ssh->queue[ssh->queuelen]);
|
|
sfree(ssh->queue);
|
|
|
|
while (ssh->qhead) {
|
|
struct queued_handler *qh = ssh->qhead;
|
|
ssh->qhead = qh->next;
|
|
sfree(ssh->qhead);
|
|
}
|
|
ssh->qhead = ssh->qtail = NULL;
|
|
|
|
if (ssh->channels) {
|
|
while ((c = delpos234(ssh->channels, 0)) != NULL) {
|
|
switch (c->type) {
|
|
case CHAN_X11:
|
|
if (c->u.x11.s != NULL)
|
|
x11_close(c->u.x11.s);
|
|
break;
|
|
case CHAN_SOCKDATA:
|
|
if (c->u.pfd.s != NULL)
|
|
pfd_close(c->u.pfd.s);
|
|
break;
|
|
}
|
|
sfree(c);
|
|
}
|
|
freetree234(ssh->channels);
|
|
ssh->channels = NULL;
|
|
}
|
|
|
|
if (ssh->rportfwds) {
|
|
while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
|
|
sfree(pf);
|
|
freetree234(ssh->rportfwds);
|
|
ssh->rportfwds = NULL;
|
|
}
|
|
sfree(ssh->deferred_send_data);
|
|
if (ssh->x11disp)
|
|
x11_free_display(ssh->x11disp);
|
|
sfree(ssh->do_ssh_init_state);
|
|
sfree(ssh->do_ssh1_login_state);
|
|
sfree(ssh->do_ssh2_transport_state);
|
|
sfree(ssh->do_ssh2_authconn_state);
|
|
sfree(ssh->v_c);
|
|
sfree(ssh->v_s);
|
|
sfree(ssh->fullhostname);
|
|
if (ssh->crcda_ctx) {
|
|
crcda_free_context(ssh->crcda_ctx);
|
|
ssh->crcda_ctx = NULL;
|
|
}
|
|
if (ssh->s)
|
|
ssh_do_close(ssh, TRUE);
|
|
expire_timer_context(ssh);
|
|
if (ssh->pinger)
|
|
pinger_free(ssh->pinger);
|
|
bufchain_clear(&ssh->queued_incoming_data);
|
|
sfree(ssh);
|
|
|
|
random_unref();
|
|
}
|
|
|
|
/*
|
|
* Reconfigure the SSH backend.
|
|
*/
|
|
static void ssh_reconfig(void *handle, Config *cfg)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
char *rekeying = NULL, rekey_mandatory = FALSE;
|
|
unsigned long old_max_data_size;
|
|
|
|
pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
|
|
if (ssh->portfwds)
|
|
ssh_setup_portfwd(ssh, cfg);
|
|
|
|
if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
|
|
cfg->ssh_rekey_time != 0) {
|
|
long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
|
|
long now = GETTICKCOUNT();
|
|
|
|
if (new_next - now < 0) {
|
|
rekeying = "timeout shortened";
|
|
} else {
|
|
ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
|
|
}
|
|
}
|
|
|
|
old_max_data_size = ssh->max_data_size;
|
|
ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
|
|
if (old_max_data_size != ssh->max_data_size &&
|
|
ssh->max_data_size != 0) {
|
|
if (ssh->outgoing_data_size > ssh->max_data_size ||
|
|
ssh->incoming_data_size > ssh->max_data_size)
|
|
rekeying = "data limit lowered";
|
|
}
|
|
|
|
if (ssh->cfg.compression != cfg->compression) {
|
|
rekeying = "compression setting changed";
|
|
rekey_mandatory = TRUE;
|
|
}
|
|
|
|
if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
|
|
memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
|
|
sizeof(ssh->cfg.ssh_cipherlist))) {
|
|
rekeying = "cipher settings changed";
|
|
rekey_mandatory = TRUE;
|
|
}
|
|
|
|
ssh->cfg = *cfg; /* STRUCTURE COPY */
|
|
|
|
if (rekeying) {
|
|
if (!ssh->kex_in_progress) {
|
|
do_ssh2_transport(ssh, rekeying, -1, NULL);
|
|
} else if (rekey_mandatory) {
|
|
ssh->deferred_rekey_reason = rekeying;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Called to send data down the SSH connection.
|
|
*/
|
|
static int ssh_send(void *handle, char *buf, int len)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
|
|
if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
|
|
return 0;
|
|
|
|
ssh->protocol(ssh, (unsigned char *)buf, len, 0);
|
|
|
|
return ssh_sendbuffer(ssh);
|
|
}
|
|
|
|
/*
|
|
* Called to query the current amount of buffered stdin data.
|
|
*/
|
|
static int ssh_sendbuffer(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
int override_value;
|
|
|
|
if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
|
|
return 0;
|
|
|
|
/*
|
|
* If the SSH socket itself has backed up, add the total backup
|
|
* size on that to any individual buffer on the stdin channel.
|
|
*/
|
|
override_value = 0;
|
|
if (ssh->throttled_all)
|
|
override_value = ssh->overall_bufsize;
|
|
|
|
if (ssh->version == 1) {
|
|
return override_value;
|
|
} else if (ssh->version == 2) {
|
|
if (!ssh->mainchan || ssh->mainchan->closes > 0)
|
|
return override_value;
|
|
else
|
|
return (override_value +
|
|
bufchain_size(&ssh->mainchan->v.v2.outbuffer));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Called to set the size of the window from SSH's POV.
|
|
*/
|
|
static void ssh_size(void *handle, int width, int height)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
struct Packet *pktout;
|
|
|
|
ssh->term_width = width;
|
|
ssh->term_height = height;
|
|
|
|
switch (ssh->state) {
|
|
case SSH_STATE_BEFORE_SIZE:
|
|
case SSH_STATE_PREPACKET:
|
|
case SSH_STATE_CLOSED:
|
|
break; /* do nothing */
|
|
case SSH_STATE_INTERMED:
|
|
ssh->size_needed = TRUE; /* buffer for later */
|
|
break;
|
|
case SSH_STATE_SESSION:
|
|
if (!ssh->cfg.nopty) {
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
|
|
PKT_INT, ssh->term_height,
|
|
PKT_INT, ssh->term_width,
|
|
PKT_INT, 0, PKT_INT, 0, PKT_END);
|
|
} else if (ssh->mainchan) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(pktout, "window-change");
|
|
ssh2_pkt_addbool(pktout, 0);
|
|
ssh2_pkt_adduint32(pktout, ssh->term_width);
|
|
ssh2_pkt_adduint32(pktout, ssh->term_height);
|
|
ssh2_pkt_adduint32(pktout, 0);
|
|
ssh2_pkt_adduint32(pktout, 0);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Return a list of the special codes that make sense in this
|
|
* protocol.
|
|
*/
|
|
static const struct telnet_special *ssh_get_specials(void *handle)
|
|
{
|
|
static const struct telnet_special ssh1_ignore_special[] = {
|
|
{"IGNORE message", TS_NOP}
|
|
};
|
|
static const struct telnet_special ssh2_transport_specials[] = {
|
|
{"IGNORE message", TS_NOP},
|
|
{"Repeat key exchange", TS_REKEY},
|
|
};
|
|
static const struct telnet_special ssh2_session_specials[] = {
|
|
{NULL, TS_SEP},
|
|
{"Break", TS_BRK},
|
|
/* These are the signal names defined by RFC 4254.
|
|
* They include all the ISO C signals, but are a subset of the POSIX
|
|
* required signals. */
|
|
{"SIGINT (Interrupt)", TS_SIGINT},
|
|
{"SIGTERM (Terminate)", TS_SIGTERM},
|
|
{"SIGKILL (Kill)", TS_SIGKILL},
|
|
{"SIGQUIT (Quit)", TS_SIGQUIT},
|
|
{"SIGHUP (Hangup)", TS_SIGHUP},
|
|
{"More signals", TS_SUBMENU},
|
|
{"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
|
|
{"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
|
|
{"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
|
|
{"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
|
|
{NULL, TS_EXITMENU}
|
|
};
|
|
static const struct telnet_special specials_end[] = {
|
|
{NULL, TS_EXITMENU}
|
|
};
|
|
/* XXX review this length for any changes: */
|
|
static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
|
|
lenof(ssh2_session_specials) +
|
|
lenof(specials_end)];
|
|
Ssh ssh = (Ssh) handle;
|
|
int i = 0;
|
|
#define ADD_SPECIALS(name) \
|
|
do { \
|
|
assert((i + lenof(name)) <= lenof(ssh_specials)); \
|
|
memcpy(&ssh_specials[i], name, sizeof name); \
|
|
i += lenof(name); \
|
|
} while(0)
|
|
|
|
if (ssh->version == 1) {
|
|
/* Don't bother offering IGNORE if we've decided the remote
|
|
* won't cope with it, since we wouldn't bother sending it if
|
|
* asked anyway. */
|
|
if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
|
|
ADD_SPECIALS(ssh1_ignore_special);
|
|
} else if (ssh->version == 2) {
|
|
ADD_SPECIALS(ssh2_transport_specials);
|
|
if (ssh->mainchan)
|
|
ADD_SPECIALS(ssh2_session_specials);
|
|
} /* else we're not ready yet */
|
|
|
|
if (i) {
|
|
ADD_SPECIALS(specials_end);
|
|
return ssh_specials;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
#undef ADD_SPECIALS
|
|
}
|
|
|
|
/*
|
|
* Send special codes. TS_EOF is useful for `plink', so you
|
|
* can send an EOF and collect resulting output (e.g. `plink
|
|
* hostname sort').
|
|
*/
|
|
static void ssh_special(void *handle, Telnet_Special code)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
struct Packet *pktout;
|
|
|
|
if (code == TS_EOF) {
|
|
if (ssh->state != SSH_STATE_SESSION) {
|
|
/*
|
|
* Buffer the EOF in case we are pre-SESSION, so we can
|
|
* send it as soon as we reach SESSION.
|
|
*/
|
|
if (code == TS_EOF)
|
|
ssh->eof_needed = TRUE;
|
|
return;
|
|
}
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
|
|
} else if (ssh->mainchan) {
|
|
struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
|
|
ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
ssh->send_ok = 0; /* now stop trying to read from stdin */
|
|
}
|
|
logevent("Sent EOF message");
|
|
} else if (code == TS_PING || code == TS_NOP) {
|
|
if (ssh->state == SSH_STATE_CLOSED
|
|
|| ssh->state == SSH_STATE_PREPACKET) return;
|
|
if (ssh->version == 1) {
|
|
if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
|
|
send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
|
|
} else {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
|
|
ssh2_pkt_addstring_start(pktout);
|
|
ssh2_pkt_send_noqueue(ssh, pktout);
|
|
}
|
|
} else if (code == TS_REKEY) {
|
|
if (!ssh->kex_in_progress && ssh->version == 2) {
|
|
do_ssh2_transport(ssh, "at user request", -1, NULL);
|
|
}
|
|
} else if (code == TS_BRK) {
|
|
if (ssh->state == SSH_STATE_CLOSED
|
|
|| ssh->state == SSH_STATE_PREPACKET) return;
|
|
if (ssh->version == 1) {
|
|
logevent("Unable to send BREAK signal in SSH-1");
|
|
} else if (ssh->mainchan) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(pktout, "break");
|
|
ssh2_pkt_addbool(pktout, 0);
|
|
ssh2_pkt_adduint32(pktout, 0); /* default break length */
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
} else {
|
|
/* Is is a POSIX signal? */
|
|
char *signame = NULL;
|
|
if (code == TS_SIGABRT) signame = "ABRT";
|
|
if (code == TS_SIGALRM) signame = "ALRM";
|
|
if (code == TS_SIGFPE) signame = "FPE";
|
|
if (code == TS_SIGHUP) signame = "HUP";
|
|
if (code == TS_SIGILL) signame = "ILL";
|
|
if (code == TS_SIGINT) signame = "INT";
|
|
if (code == TS_SIGKILL) signame = "KILL";
|
|
if (code == TS_SIGPIPE) signame = "PIPE";
|
|
if (code == TS_SIGQUIT) signame = "QUIT";
|
|
if (code == TS_SIGSEGV) signame = "SEGV";
|
|
if (code == TS_SIGTERM) signame = "TERM";
|
|
if (code == TS_SIGUSR1) signame = "USR1";
|
|
if (code == TS_SIGUSR2) signame = "USR2";
|
|
/* The SSH-2 protocol does in principle support arbitrary named
|
|
* signals, including signame@domain, but we don't support those. */
|
|
if (signame) {
|
|
/* It's a signal. */
|
|
if (ssh->version == 2 && ssh->mainchan) {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
|
|
ssh2_pkt_addstring(pktout, "signal");
|
|
ssh2_pkt_addbool(pktout, 0);
|
|
ssh2_pkt_addstring(pktout, signame);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
logeventf(ssh, "Sent signal SIG%s", signame);
|
|
}
|
|
} else {
|
|
/* Never heard of it. Do nothing */
|
|
}
|
|
}
|
|
}
|
|
|
|
void *new_sock_channel(void *handle, Socket s)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
struct ssh_channel *c;
|
|
c = snew(struct ssh_channel);
|
|
|
|
c->ssh = ssh;
|
|
ssh2_channel_init(c);
|
|
c->halfopen = TRUE;
|
|
c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
|
|
c->u.pfd.s = s;
|
|
add234(ssh->channels, c);
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* This is called when stdout/stderr (the entity to which
|
|
* from_backend sends data) manages to clear some backlog.
|
|
*/
|
|
static void ssh_unthrottle(void *handle, int bufsize)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
int buflimit;
|
|
|
|
if (ssh->version == 1) {
|
|
if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
|
|
ssh->v1_stdout_throttling = 0;
|
|
ssh_throttle_conn(ssh, -1);
|
|
}
|
|
} else {
|
|
if (ssh->mainchan) {
|
|
ssh2_set_window(ssh->mainchan,
|
|
bufsize < ssh->mainchan->v.v2.locmaxwin ?
|
|
ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
|
|
if (ssh->cfg.ssh_simple)
|
|
buflimit = 0;
|
|
else
|
|
buflimit = ssh->mainchan->v.v2.locmaxwin;
|
|
if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
|
|
ssh->mainchan->throttling_conn = 0;
|
|
ssh_throttle_conn(ssh, -1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
|
|
{
|
|
struct ssh_channel *c = (struct ssh_channel *)channel;
|
|
Ssh ssh = c->ssh;
|
|
struct Packet *pktout;
|
|
|
|
logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
|
|
|
|
if (ssh->version == 1) {
|
|
send_packet(ssh, SSH1_MSG_PORT_OPEN,
|
|
PKT_INT, c->localid,
|
|
PKT_STR, hostname,
|
|
PKT_INT, port,
|
|
/* PKT_STR, <org:orgport>, */
|
|
PKT_END);
|
|
} else {
|
|
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
|
|
ssh2_pkt_addstring(pktout, "direct-tcpip");
|
|
ssh2_pkt_adduint32(pktout, c->localid);
|
|
ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
|
|
ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
|
|
ssh2_pkt_addstring(pktout, hostname);
|
|
ssh2_pkt_adduint32(pktout, port);
|
|
/*
|
|
* We make up values for the originator data; partly it's
|
|
* too much hassle to keep track, and partly I'm not
|
|
* convinced the server should be told details like that
|
|
* about my local network configuration.
|
|
* The "originator IP address" is syntactically a numeric
|
|
* IP address, and some servers (e.g., Tectia) get upset
|
|
* if it doesn't match this syntax.
|
|
*/
|
|
ssh2_pkt_addstring(pktout, "0.0.0.0");
|
|
ssh2_pkt_adduint32(pktout, 0);
|
|
ssh2_pkt_send(ssh, pktout);
|
|
}
|
|
}
|
|
|
|
static int ssh_connected(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
return ssh->s != NULL;
|
|
}
|
|
|
|
static int ssh_sendok(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
return ssh->send_ok;
|
|
}
|
|
|
|
static int ssh_ldisc(void *handle, int option)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
if (option == LD_ECHO)
|
|
return ssh->echoing;
|
|
if (option == LD_EDIT)
|
|
return ssh->editing;
|
|
return FALSE;
|
|
}
|
|
|
|
static void ssh_provide_ldisc(void *handle, void *ldisc)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
ssh->ldisc = ldisc;
|
|
}
|
|
|
|
static void ssh_provide_logctx(void *handle, void *logctx)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
ssh->logctx = logctx;
|
|
}
|
|
|
|
static int ssh_return_exitcode(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
if (ssh->s != NULL)
|
|
return -1;
|
|
else
|
|
return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
|
|
}
|
|
|
|
/*
|
|
* cfg_info for SSH is the currently running version of the
|
|
* protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
|
|
*/
|
|
static int ssh_cfg_info(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
return ssh->version;
|
|
}
|
|
|
|
/*
|
|
* Gross hack: pscp will try to start SFTP but fall back to scp1 if
|
|
* that fails. This variable is the means by which scp.c can reach
|
|
* into the SSH code and find out which one it got.
|
|
*/
|
|
extern int ssh_fallback_cmd(void *handle)
|
|
{
|
|
Ssh ssh = (Ssh) handle;
|
|
return ssh->fallback_cmd;
|
|
}
|
|
|
|
Backend ssh_backend = {
|
|
ssh_init,
|
|
ssh_free,
|
|
ssh_reconfig,
|
|
ssh_send,
|
|
ssh_sendbuffer,
|
|
ssh_size,
|
|
ssh_special,
|
|
ssh_get_specials,
|
|
ssh_connected,
|
|
ssh_return_exitcode,
|
|
ssh_sendok,
|
|
ssh_ldisc,
|
|
ssh_provide_ldisc,
|
|
ssh_provide_logctx,
|
|
ssh_unthrottle,
|
|
ssh_cfg_info,
|
|
"ssh",
|
|
PROT_SSH,
|
|
22
|
|
};
|