зеркало из https://github.com/github/putty.git
5354 строки
146 KiB
C
5354 строки
146 KiB
C
#include <windows.h>
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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 "putty.h"
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#include "tree234.h"
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#include "ssh.h"
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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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/* uncomment this for packet level debugging */
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/* #define DUMP_PACKETS */
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#define logevent(s) { logevent(s); \
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if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
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{ fprintf(stderr, "%s\n", s); fflush(stderr); } }
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#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
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(s ? sk_close(s), s = NULL : 0), \
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connection_fatal msg )
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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_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_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_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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"SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
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"SSH_DISCONNECT_PROTOCOL_ERROR",
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"SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
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"SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
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"SSH_DISCONNECT_MAC_ERROR",
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"SSH_DISCONNECT_COMPRESSION_ERROR",
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"SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
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"SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
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"SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
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"SSH_DISCONNECT_CONNECTION_LOST",
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"SSH_DISCONNECT_BY_APPLICATION",
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"SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
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"SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
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"SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
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"SSH_DISCONNECT_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 GET_32BIT(cp) \
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(((unsigned long)(unsigned char)(cp)[0] << 24) | \
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((unsigned long)(unsigned char)(cp)[1] << 16) | \
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((unsigned long)(unsigned char)(cp)[2] << 8) | \
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((unsigned long)(unsigned char)(cp)[3]))
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#define PUT_32BIT(cp, value) { \
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(cp)[0] = (unsigned char)((value) >> 24); \
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(cp)[1] = (unsigned char)((value) >> 16); \
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(cp)[2] = (unsigned char)((value) >> 8); \
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(cp)[3] = (unsigned char)(value); }
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enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
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/* Coroutine mechanics for the sillier bits of the code */
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#define crBegin1 static int crLine = 0;
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#define crBegin2 switch(crLine) { case 0:;
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#define crBegin crBegin1; crBegin2;
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#define crFinish(z) } crLine = 0; return (z)
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#define crFinishV } crLine = 0; return
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#define crReturn(z) \
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do {\
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crLine=__LINE__; return (z); case __LINE__:;\
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} while (0)
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#define crReturnV \
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do {\
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crLine=__LINE__; return; case __LINE__:;\
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} while (0)
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#define crStop(z) do{ crLine = 0; return (z); }while(0)
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#define crStopV do{ crLine = 0; return; }while(0)
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#define crWaitUntil(c) do { crReturn(0); } while (!(c))
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#define crWaitUntilV(c) do { crReturnV; } while (!(c))
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extern char *x11_init(Socket *, char *, void *);
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extern void x11_close(Socket);
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extern int x11_send(Socket, char *, int);
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extern void x11_invent_auth(char *, int, char *, int);
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extern void x11_unthrottle(Socket s);
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extern void x11_override_throttle(Socket s, int enable);
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extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
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extern char *pfd_addforward(char *desthost, int destport, int port);
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extern void pfd_close(Socket s);
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extern int pfd_send(Socket s, char *data, int len);
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extern void pfd_confirm(Socket s);
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extern void pfd_unthrottle(Socket s);
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extern void pfd_override_throttle(Socket s, int enable);
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/*
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* Buffer management constants. There are several of these for
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* various different purposes:
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*
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* - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
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* on a local data stream before we throttle the whole SSH
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* connection (in SSH1 only). Throttling the whole connection is
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* pretty drastic so we set this high in the hope it won't
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* happen very often.
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*
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* - SSH_MAX_BACKLOG is the amount of backlog that must build up
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* on the SSH connection itself before we defensively throttle
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* _all_ local data streams. This is pretty drastic too (though
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* thankfully unlikely in SSH2 since the window mechanism should
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* ensure that the server never has any need to throttle its end
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* of the connection), so we set this high as well.
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*
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* - OUR_V2_WINSIZE is the maximum window size we present on SSH2
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* channels.
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*/
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#define SSH1_BUFFER_LIMIT 32768
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#define SSH_MAX_BACKLOG 32768
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#define OUR_V2_WINSIZE 16384
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/*
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* Ciphers for SSH2.
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*/
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const static struct ssh2_ciphers *ciphers[] = {
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&ssh2_aes,
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&ssh2_blowfish,
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&ssh2_3des,
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&ssh2_des,
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};
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const static struct ssh_kex *kex_algs[] = {
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&ssh_diffiehellman_gex,
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&ssh_diffiehellman
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};
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const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
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static void nullmac_key(unsigned char *key)
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{
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}
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static void nullmac_generate(unsigned char *blk, int len,
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unsigned long seq)
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{
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}
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static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
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{
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return 1;
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}
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const static struct ssh_mac ssh_mac_none = {
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nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
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};
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const static struct ssh_mac *macs[] = {
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&ssh_sha1, &ssh_md5, &ssh_mac_none
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};
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const static struct ssh_mac *buggymacs[] = {
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&ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
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};
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static void ssh_comp_none_init(void)
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{
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}
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static int ssh_comp_none_block(unsigned char *block, int len,
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unsigned char **outblock, int *outlen)
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{
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return 0;
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}
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static int ssh_comp_none_disable(void)
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{
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return 0;
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}
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const static struct ssh_compress ssh_comp_none = {
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"none",
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ssh_comp_none_init, ssh_comp_none_block,
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ssh_comp_none_init, ssh_comp_none_block,
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ssh_comp_none_disable
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};
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extern const struct ssh_compress ssh_zlib;
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const static struct ssh_compress *compressions[] = {
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&ssh_zlib, &ssh_comp_none
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};
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enum { /* channel types */
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CHAN_MAINSESSION,
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CHAN_X11,
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CHAN_AGENT,
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CHAN_SOCKDATA,
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CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
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};
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/*
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* 2-3-4 tree storing channels.
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*/
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struct ssh_channel {
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unsigned remoteid, localid;
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int type;
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int closes;
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union {
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struct ssh1_data_channel {
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int throttling;
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} v1;
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struct ssh2_data_channel {
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bufchain outbuffer;
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unsigned remwindow, remmaxpkt;
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unsigned locwindow;
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} v2;
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} v;
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union {
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struct ssh_agent_channel {
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unsigned char *message;
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unsigned char msglen[4];
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int lensofar, totallen;
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} a;
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struct ssh_x11_channel {
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Socket s;
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} x11;
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struct ssh_pfd_channel {
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Socket s;
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} pfd;
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} u;
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};
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/*
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* 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
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* 2 use this structure in different ways, reflecting SSH 2's
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* altogether saner approach to port forwarding.
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*
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* In SSH 1, you arrange a remote forwarding by sending the server
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* the remote port number, and the local destination host:port.
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* When a connection comes in, the server sends you back that
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* host:port pair, and you connect to it. This is a ready-made
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* security hole if you're not on the ball: a malicious server
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* could send you back _any_ host:port pair, so if you trustingly
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* connect to the address it gives you then you've just opened the
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* entire inside of your corporate network just by connecting
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* through it to a dodgy SSH server. Hence, we must store a list of
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* host:port pairs we _are_ trying to forward to, and reject a
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* connection request from the server if it's not in the list.
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*
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* In SSH 2, each side of the connection minds its own business and
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* doesn't send unnecessary information to the other. You arrange a
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* remote forwarding by sending the server just the remote port
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* number. When a connection comes in, the server tells you which
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* of its ports was connected to; and _you_ have to remember what
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* local host:port pair went with that port number.
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*
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* Hence: in SSH 1 this structure stores host:port pairs we intend
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* to allow connections to, and is indexed by those host:port
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* pairs. In SSH 2 it stores a mapping from source port to
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* destination host:port pair, and is indexed by source port.
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*/
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struct ssh_rportfwd {
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unsigned sport, dport;
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char dhost[256];
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};
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struct Packet {
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long length;
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int type;
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unsigned char *data;
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unsigned char *body;
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long savedpos;
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long maxlen;
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};
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static SHA_State exhash, exhashbase;
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static Socket s = NULL;
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static unsigned char session_key[32];
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static int ssh1_compressing;
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static int ssh1_remote_protoflags;
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static int ssh1_local_protoflags;
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static int ssh_agentfwd_enabled;
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static int ssh_X11_fwd_enabled;
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static int ssh_remote_bugs;
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static const struct ssh_cipher *cipher = NULL;
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static const struct ssh2_cipher *cscipher = NULL;
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static const struct ssh2_cipher *sccipher = NULL;
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static const struct ssh_mac *csmac = NULL;
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static const struct ssh_mac *scmac = NULL;
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static const struct ssh_compress *cscomp = NULL;
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static const struct ssh_compress *sccomp = NULL;
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static const struct ssh_kex *kex = NULL;
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static const struct ssh_signkey *hostkey = NULL;
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static unsigned char ssh2_session_id[20];
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int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
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int is_pw) = NULL;
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static char *savedhost;
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static int savedport;
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static int ssh_send_ok;
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static int ssh_echoing, ssh_editing;
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static tree234 *ssh_channels; /* indexed by local id */
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static struct ssh_channel *mainchan; /* primary session channel */
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static tree234 *ssh_rportfwds;
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static enum {
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SSH_STATE_PREPACKET,
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SSH_STATE_BEFORE_SIZE,
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SSH_STATE_INTERMED,
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SSH_STATE_SESSION,
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SSH_STATE_CLOSED
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} ssh_state = SSH_STATE_PREPACKET;
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static int size_needed = FALSE, eof_needed = FALSE;
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static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
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static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
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static unsigned char *deferred_send_data = NULL;
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static int deferred_len = 0, deferred_size = 0;
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/*
|
|
* 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 ssh_fallback_cmd = 0;
|
|
|
|
static int ssh_version;
|
|
static int ssh1_throttle_count;
|
|
static int ssh_overall_bufsize;
|
|
static int ssh_throttled_all;
|
|
static int ssh1_stdout_throttling;
|
|
static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
|
|
static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
|
|
static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
|
|
static void ssh_size(void);
|
|
static void ssh_special(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(int enable, int bufsize);
|
|
static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
|
|
static int (*s_rdpkt) (unsigned char **data, int *datalen);
|
|
static int ssh_sendbuffer(void);
|
|
|
|
static struct rdpkt1_state_tag {
|
|
long len, pad, biglen, to_read;
|
|
unsigned long realcrc, gotcrc;
|
|
unsigned char *p;
|
|
int i;
|
|
int chunk;
|
|
} rdpkt1_state;
|
|
|
|
static struct rdpkt2_state_tag {
|
|
long len, pad, payload, packetlen, maclen;
|
|
int i;
|
|
int cipherblk;
|
|
unsigned long incoming_sequence;
|
|
} rdpkt2_state;
|
|
|
|
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;
|
|
}
|
|
|
|
static int alloc_channel_id(void)
|
|
{
|
|
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(char *buf, int len)
|
|
{
|
|
if ((flags & FLAG_STDERR)) {
|
|
int i;
|
|
for (i = 0; i < len; i++)
|
|
if (buf[i] != '\r')
|
|
fputc(buf[i], stderr);
|
|
return;
|
|
}
|
|
from_backend(1, buf, len);
|
|
}
|
|
|
|
static void c_write_untrusted(char *buf, int len)
|
|
{
|
|
int i;
|
|
for (i = 0; i < len; i++) {
|
|
if (buf[i] == '\n')
|
|
c_write("\r\n", 2);
|
|
else if ((buf[i] & 0x60) || (buf[i] == '\r'))
|
|
c_write(buf + i, 1);
|
|
}
|
|
}
|
|
|
|
static void c_write_str(char *buf)
|
|
{
|
|
c_write(buf, strlen(buf));
|
|
}
|
|
|
|
/*
|
|
* 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 the additional nr of bytes needed, or 0 when
|
|
* a complete packet is available.
|
|
*/
|
|
static int ssh1_rdpkt(unsigned char **data, int *datalen)
|
|
{
|
|
struct rdpkt1_state_tag *st = &rdpkt1_state;
|
|
|
|
crBegin;
|
|
|
|
next_packet:
|
|
|
|
pktin.type = 0;
|
|
pktin.length = 0;
|
|
|
|
for (st->i = st->len = 0; st->i < 4; st->i++) {
|
|
while ((*datalen) == 0)
|
|
crReturn(4 - st->i);
|
|
st->len = (st->len << 8) + **data;
|
|
(*data)++, (*datalen)--;
|
|
}
|
|
|
|
st->pad = 8 - (st->len % 8);
|
|
st->biglen = st->len + st->pad;
|
|
pktin.length = st->len - 5;
|
|
|
|
if (pktin.maxlen < st->biglen) {
|
|
pktin.maxlen = st->biglen;
|
|
pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
|
|
srealloc(pktin.data, st->biglen + APIEXTRA));
|
|
if (!pktin.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
|
|
st->to_read = st->biglen;
|
|
st->p = pktin.data;
|
|
while (st->to_read > 0) {
|
|
st->chunk = st->to_read;
|
|
while ((*datalen) == 0)
|
|
crReturn(st->to_read);
|
|
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 (cipher)
|
|
cipher->decrypt(pktin.data, st->biglen);
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
|
|
dmemdump(pktin.data, st->biglen);
|
|
#endif
|
|
|
|
st->realcrc = crc32(pktin.data, st->biglen - 4);
|
|
st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
|
|
if (st->gotcrc != st->realcrc) {
|
|
bombout(("Incorrect CRC received on packet"));
|
|
crReturn(0);
|
|
}
|
|
|
|
pktin.body = pktin.data + st->pad + 1;
|
|
|
|
if (ssh1_compressing) {
|
|
unsigned char *decompblk;
|
|
int decomplen;
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Packet payload pre-decompression:\n"));
|
|
dmemdump(pktin.body - 1, pktin.length + 1);
|
|
#endif
|
|
zlib_decompress_block(pktin.body - 1, pktin.length + 1,
|
|
&decompblk, &decomplen);
|
|
|
|
if (pktin.maxlen < st->pad + decomplen) {
|
|
pktin.maxlen = st->pad + decomplen;
|
|
pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
|
|
pktin.body = pktin.data + st->pad + 1;
|
|
if (!pktin.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
|
|
memcpy(pktin.body - 1, decompblk, decomplen);
|
|
sfree(decompblk);
|
|
pktin.length = decomplen - 1;
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Packet payload post-decompression:\n"));
|
|
dmemdump(pktin.body - 1, pktin.length + 1);
|
|
#endif
|
|
}
|
|
|
|
if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
|
|
pktin.type == SSH1_SMSG_STDERR_DATA ||
|
|
pktin.type == SSH1_MSG_DEBUG ||
|
|
pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
|
|
pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
|
|
long strlen = GET_32BIT(pktin.body);
|
|
if (strlen + 4 != pktin.length) {
|
|
bombout(("Received data packet with bogus string length"));
|
|
crReturn(0);
|
|
}
|
|
}
|
|
|
|
pktin.type = pktin.body[-1];
|
|
|
|
if (pktin.type == SSH1_MSG_DEBUG) {
|
|
/* log debug message */
|
|
char buf[80];
|
|
int strlen = GET_32BIT(pktin.body);
|
|
strcpy(buf, "Remote: ");
|
|
if (strlen > 70)
|
|
strlen = 70;
|
|
memcpy(buf + 8, pktin.body + 4, strlen);
|
|
buf[8 + strlen] = '\0';
|
|
logevent(buf);
|
|
goto next_packet;
|
|
} else if (pktin.type == SSH1_MSG_IGNORE) {
|
|
/* do nothing */
|
|
goto next_packet;
|
|
}
|
|
|
|
if (pktin.type == SSH1_MSG_DISCONNECT) {
|
|
/* log reason code in disconnect message */
|
|
char buf[256];
|
|
unsigned msglen = GET_32BIT(pktin.body);
|
|
unsigned nowlen;
|
|
strcpy(buf, "Remote sent disconnect: ");
|
|
nowlen = strlen(buf);
|
|
if (msglen > sizeof(buf) - nowlen - 1)
|
|
msglen = sizeof(buf) - nowlen - 1;
|
|
memcpy(buf + nowlen, pktin.body + 4, msglen);
|
|
buf[nowlen + msglen] = '\0';
|
|
logevent(buf);
|
|
bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
|
|
crReturn(0);
|
|
}
|
|
|
|
crFinish(0);
|
|
}
|
|
|
|
static int ssh2_rdpkt(unsigned char **data, int *datalen)
|
|
{
|
|
struct rdpkt2_state_tag *st = &rdpkt2_state;
|
|
|
|
crBegin;
|
|
|
|
next_packet:
|
|
pktin.type = 0;
|
|
pktin.length = 0;
|
|
if (sccipher)
|
|
st->cipherblk = sccipher->blksize;
|
|
else
|
|
st->cipherblk = 8;
|
|
if (st->cipherblk < 8)
|
|
st->cipherblk = 8;
|
|
|
|
if (pktin.maxlen < st->cipherblk) {
|
|
pktin.maxlen = st->cipherblk;
|
|
pktin.data =
|
|
(pktin.data ==
|
|
NULL ? smalloc(st->cipherblk +
|
|
APIEXTRA) : srealloc(pktin.data,
|
|
st->cipherblk +
|
|
APIEXTRA));
|
|
if (!pktin.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
|
|
/*
|
|
* 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(st->cipherblk - st->i);
|
|
pktin.data[st->i] = *(*data)++;
|
|
(*datalen)--;
|
|
}
|
|
|
|
if (sccipher)
|
|
sccipher->decrypt(pktin.data, st->cipherblk);
|
|
|
|
/*
|
|
* Now get the length and padding figures.
|
|
*/
|
|
st->len = GET_32BIT(pktin.data);
|
|
st->pad = pktin.data[4];
|
|
|
|
/*
|
|
* This enables us to deduce the payload length.
|
|
*/
|
|
st->payload = st->len - st->pad - 1;
|
|
|
|
pktin.length = st->payload + 5;
|
|
|
|
/*
|
|
* So now we can work out the total packet length.
|
|
*/
|
|
st->packetlen = st->len + 4;
|
|
st->maclen = scmac ? scmac->len : 0;
|
|
|
|
/*
|
|
* Adjust memory allocation if packet is too big.
|
|
*/
|
|
if (pktin.maxlen < st->packetlen + st->maclen) {
|
|
pktin.maxlen = st->packetlen + st->maclen;
|
|
pktin.data =
|
|
(pktin.data ==
|
|
NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
|
|
pktin.maxlen
|
|
+
|
|
APIEXTRA));
|
|
if (!pktin.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
|
|
/*
|
|
* 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(st->packetlen + st->maclen - st->i);
|
|
pktin.data[st->i] = *(*data)++;
|
|
(*datalen)--;
|
|
}
|
|
/* Decrypt everything _except_ the MAC. */
|
|
if (sccipher)
|
|
sccipher->decrypt(pktin.data + st->cipherblk,
|
|
st->packetlen - st->cipherblk);
|
|
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
|
|
dmemdump(pktin.data, st->packetlen);
|
|
#endif
|
|
|
|
/*
|
|
* Check the MAC.
|
|
*/
|
|
if (scmac
|
|
&& !scmac->verify(pktin.data, st->len + 4,
|
|
st->incoming_sequence)) {
|
|
bombout(("Incorrect MAC received on packet"));
|
|
crReturn(0);
|
|
}
|
|
st->incoming_sequence++; /* whether or not we MACed */
|
|
|
|
/*
|
|
* Decompress packet payload.
|
|
*/
|
|
{
|
|
unsigned char *newpayload;
|
|
int newlen;
|
|
if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
|
|
&newpayload, &newlen)) {
|
|
if (pktin.maxlen < newlen + 5) {
|
|
pktin.maxlen = newlen + 5;
|
|
pktin.data =
|
|
(pktin.data ==
|
|
NULL ? smalloc(pktin.maxlen +
|
|
APIEXTRA) : srealloc(pktin.data,
|
|
pktin.maxlen +
|
|
APIEXTRA));
|
|
if (!pktin.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
pktin.length = 5 + newlen;
|
|
memcpy(pktin.data + 5, newpayload, newlen);
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Post-decompression payload:\n"));
|
|
dmemdump(pktin.data + 5, newlen);
|
|
#endif
|
|
|
|
sfree(newpayload);
|
|
}
|
|
}
|
|
|
|
pktin.savedpos = 6;
|
|
pktin.type = pktin.data[5];
|
|
|
|
if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
|
|
goto next_packet; /* FIXME: print DEBUG message */
|
|
|
|
if (pktin.type == SSH2_MSG_DISCONNECT) {
|
|
/* log reason code in disconnect message */
|
|
char buf[256];
|
|
int reason = GET_32BIT(pktin.data + 6);
|
|
unsigned msglen = GET_32BIT(pktin.data + 10);
|
|
unsigned nowlen;
|
|
if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
|
|
sprintf(buf, "Received disconnect message (%s)",
|
|
ssh2_disconnect_reasons[reason]);
|
|
} else {
|
|
sprintf(buf, "Received disconnect message (unknown type %d)",
|
|
reason);
|
|
}
|
|
logevent(buf);
|
|
strcpy(buf, "Disconnection message text: ");
|
|
nowlen = strlen(buf);
|
|
if (msglen > sizeof(buf) - nowlen - 1)
|
|
msglen = sizeof(buf) - nowlen - 1;
|
|
memcpy(buf + nowlen, pktin.data + 14, msglen);
|
|
buf[nowlen + msglen] = '\0';
|
|
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",
|
|
buf+nowlen));
|
|
crReturn(0);
|
|
}
|
|
|
|
crFinish(0);
|
|
}
|
|
|
|
static void ssh1_pktout_size(int len)
|
|
{
|
|
int pad, biglen;
|
|
|
|
len += 5; /* type and CRC */
|
|
pad = 8 - (len % 8);
|
|
biglen = len + pad;
|
|
|
|
pktout.length = len - 5;
|
|
if (pktout.maxlen < biglen) {
|
|
pktout.maxlen = biglen;
|
|
#ifdef MSCRYPTOAPI
|
|
/* Allocate enough buffer space for extra block
|
|
* for MS CryptEncrypt() */
|
|
pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
|
|
srealloc(pktout.data, biglen + 12));
|
|
#else
|
|
pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
|
|
srealloc(pktout.data, biglen + 4));
|
|
#endif
|
|
if (!pktout.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
pktout.body = pktout.data + 4 + pad + 1;
|
|
}
|
|
|
|
static void s_wrpkt_start(int type, int len)
|
|
{
|
|
ssh1_pktout_size(len);
|
|
pktout.type = type;
|
|
}
|
|
|
|
static int s_wrpkt_prepare(void)
|
|
{
|
|
int pad, len, biglen, i;
|
|
unsigned long crc;
|
|
|
|
pktout.body[-1] = pktout.type;
|
|
|
|
if (ssh1_compressing) {
|
|
unsigned char *compblk;
|
|
int complen;
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Packet payload pre-compression:\n"));
|
|
dmemdump(pktout.body - 1, pktout.length + 1);
|
|
#endif
|
|
zlib_compress_block(pktout.body - 1, pktout.length + 1,
|
|
&compblk, &complen);
|
|
ssh1_pktout_size(complen - 1);
|
|
memcpy(pktout.body - 1, compblk, complen);
|
|
sfree(compblk);
|
|
}
|
|
|
|
len = pktout.length + 5; /* type and CRC */
|
|
pad = 8 - (len % 8);
|
|
biglen = len + pad;
|
|
|
|
for (i = 0; i < pad; i++)
|
|
pktout.data[i + 4] = random_byte();
|
|
crc = crc32(pktout.data + 4, biglen - 4);
|
|
PUT_32BIT(pktout.data + biglen, crc);
|
|
PUT_32BIT(pktout.data, len);
|
|
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Sending packet len=%d\n", biglen + 4));
|
|
dmemdump(pktout.data, biglen + 4);
|
|
#endif
|
|
if (cipher)
|
|
cipher->encrypt(pktout.data + 4, biglen);
|
|
|
|
return biglen + 4;
|
|
}
|
|
|
|
static void s_wrpkt(void)
|
|
{
|
|
int len, backlog;
|
|
len = s_wrpkt_prepare();
|
|
backlog = sk_write(s, pktout.data, len);
|
|
if (backlog > SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(1, backlog);
|
|
}
|
|
|
|
static void s_wrpkt_defer(void)
|
|
{
|
|
int len;
|
|
len = s_wrpkt_prepare();
|
|
if (deferred_len + len > deferred_size) {
|
|
deferred_size = deferred_len + len + 128;
|
|
deferred_send_data = srealloc(deferred_send_data, deferred_size);
|
|
}
|
|
memcpy(deferred_send_data + deferred_len, pktout.data, len);
|
|
deferred_len += len;
|
|
}
|
|
|
|
/*
|
|
* Construct a packet with the specified contents.
|
|
*/
|
|
static void construct_packet(int pkttype, va_list ap1, va_list ap2)
|
|
{
|
|
unsigned char *p, *argp, argchar;
|
|
unsigned long argint;
|
|
int pktlen, argtype, arglen;
|
|
Bignum bn;
|
|
|
|
pktlen = 0;
|
|
while ((argtype = va_arg(ap1, int)) != PKT_END) {
|
|
switch (argtype) {
|
|
case PKT_INT:
|
|
(void) va_arg(ap1, int);
|
|
pktlen += 4;
|
|
break;
|
|
case PKT_CHAR:
|
|
(void) va_arg(ap1, char);
|
|
pktlen++;
|
|
break;
|
|
case PKT_DATA:
|
|
(void) va_arg(ap1, unsigned char *);
|
|
arglen = va_arg(ap1, int);
|
|
pktlen += arglen;
|
|
break;
|
|
case PKT_STR:
|
|
argp = va_arg(ap1, unsigned char *);
|
|
arglen = strlen(argp);
|
|
pktlen += 4 + arglen;
|
|
break;
|
|
case PKT_BIGNUM:
|
|
bn = va_arg(ap1, Bignum);
|
|
pktlen += ssh1_bignum_length(bn);
|
|
break;
|
|
default:
|
|
assert(0);
|
|
}
|
|
}
|
|
|
|
s_wrpkt_start(pkttype, pktlen);
|
|
p = pktout.body;
|
|
|
|
while ((argtype = va_arg(ap2, int)) != PKT_END) {
|
|
switch (argtype) {
|
|
case PKT_INT:
|
|
argint = va_arg(ap2, int);
|
|
PUT_32BIT(p, argint);
|
|
p += 4;
|
|
break;
|
|
case PKT_CHAR:
|
|
argchar = va_arg(ap2, unsigned char);
|
|
*p = argchar;
|
|
p++;
|
|
break;
|
|
case PKT_DATA:
|
|
argp = va_arg(ap2, unsigned char *);
|
|
arglen = va_arg(ap2, int);
|
|
memcpy(p, argp, arglen);
|
|
p += arglen;
|
|
break;
|
|
case PKT_STR:
|
|
argp = va_arg(ap2, unsigned char *);
|
|
arglen = strlen(argp);
|
|
PUT_32BIT(p, arglen);
|
|
memcpy(p + 4, argp, arglen);
|
|
p += 4 + arglen;
|
|
break;
|
|
case PKT_BIGNUM:
|
|
bn = va_arg(ap2, Bignum);
|
|
p += ssh1_write_bignum(p, bn);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void send_packet(int pkttype, ...)
|
|
{
|
|
va_list ap1, ap2;
|
|
va_start(ap1, pkttype);
|
|
va_start(ap2, pkttype);
|
|
construct_packet(pkttype, ap1, ap2);
|
|
s_wrpkt();
|
|
}
|
|
|
|
static void defer_packet(int pkttype, ...)
|
|
{
|
|
va_list ap1, ap2;
|
|
va_start(ap1, pkttype);
|
|
va_start(ap2, pkttype);
|
|
construct_packet(pkttype, ap1, ap2);
|
|
s_wrpkt_defer();
|
|
}
|
|
|
|
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 SHA state.
|
|
*/
|
|
#include <stdio.h>
|
|
static void sha_string(SHA_State * s, void *str, int len)
|
|
{
|
|
unsigned char lenblk[4];
|
|
PUT_32BIT(lenblk, len);
|
|
SHA_Bytes(s, lenblk, 4);
|
|
SHA_Bytes(s, str, len);
|
|
}
|
|
|
|
static void sha_uint32(SHA_State * s, unsigned i)
|
|
{
|
|
unsigned char intblk[4];
|
|
PUT_32BIT(intblk, i);
|
|
SHA_Bytes(s, intblk, 4);
|
|
}
|
|
|
|
/*
|
|
* SSH2 packet construction functions.
|
|
*/
|
|
static void ssh2_pkt_ensure(int length)
|
|
{
|
|
if (pktout.maxlen < length) {
|
|
pktout.maxlen = length + 256;
|
|
pktout.data =
|
|
(pktout.data ==
|
|
NULL ? smalloc(pktout.maxlen +
|
|
APIEXTRA) : srealloc(pktout.data,
|
|
pktout.maxlen +
|
|
APIEXTRA));
|
|
if (!pktout.data)
|
|
fatalbox("Out of memory");
|
|
}
|
|
}
|
|
static void ssh2_pkt_adddata(void *data, int len)
|
|
{
|
|
pktout.length += len;
|
|
ssh2_pkt_ensure(pktout.length);
|
|
memcpy(pktout.data + pktout.length - len, data, len);
|
|
}
|
|
static void ssh2_pkt_addbyte(unsigned char byte)
|
|
{
|
|
ssh2_pkt_adddata(&byte, 1);
|
|
}
|
|
static void ssh2_pkt_init(int pkt_type)
|
|
{
|
|
pktout.length = 5;
|
|
ssh2_pkt_addbyte((unsigned char) pkt_type);
|
|
}
|
|
static void ssh2_pkt_addbool(unsigned char value)
|
|
{
|
|
ssh2_pkt_adddata(&value, 1);
|
|
}
|
|
static void ssh2_pkt_adduint32(unsigned long value)
|
|
{
|
|
unsigned char x[4];
|
|
PUT_32BIT(x, value);
|
|
ssh2_pkt_adddata(x, 4);
|
|
}
|
|
static void ssh2_pkt_addstring_start(void)
|
|
{
|
|
ssh2_pkt_adduint32(0);
|
|
pktout.savedpos = pktout.length;
|
|
}
|
|
static void ssh2_pkt_addstring_str(char *data)
|
|
{
|
|
ssh2_pkt_adddata(data, strlen(data));
|
|
PUT_32BIT(pktout.data + pktout.savedpos - 4,
|
|
pktout.length - pktout.savedpos);
|
|
}
|
|
static void ssh2_pkt_addstring_data(char *data, int len)
|
|
{
|
|
ssh2_pkt_adddata(data, len);
|
|
PUT_32BIT(pktout.data + pktout.savedpos - 4,
|
|
pktout.length - pktout.savedpos);
|
|
}
|
|
static void ssh2_pkt_addstring(char *data)
|
|
{
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_str(data);
|
|
}
|
|
static char *ssh2_mpint_fmt(Bignum b, int *len)
|
|
{
|
|
unsigned char *p;
|
|
int i, n = (bignum_bitcount(b) + 7) / 8;
|
|
p = smalloc(n + 1);
|
|
if (!p)
|
|
fatalbox("out of memory");
|
|
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(Bignum b)
|
|
{
|
|
unsigned char *p;
|
|
int len;
|
|
p = ssh2_mpint_fmt(b, &len);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(p, len);
|
|
sfree(p);
|
|
}
|
|
|
|
/*
|
|
* Construct an SSH2 final-form packet: compress it, encrypt it,
|
|
* put the MAC on it. Final packet, ready to be sent, is stored in
|
|
* pktout.data. Total length is returned.
|
|
*/
|
|
static int ssh2_pkt_construct(void)
|
|
{
|
|
int cipherblk, maclen, padding, i;
|
|
static unsigned long outgoing_sequence = 0;
|
|
|
|
/*
|
|
* Compress packet payload.
|
|
*/
|
|
{
|
|
unsigned char *newpayload;
|
|
int newlen;
|
|
#ifdef DUMP_PACKETS
|
|
if (cscomp && cscomp != &ssh_comp_none) {
|
|
debug(("Pre-compression payload:\n"));
|
|
dmemdump(pktout.data + 5, pktout.length - 5);
|
|
}
|
|
#endif
|
|
if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
|
|
&newpayload, &newlen)) {
|
|
pktout.length = 5;
|
|
ssh2_pkt_adddata(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.
|
|
*/
|
|
cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
|
|
cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
|
|
padding = 4;
|
|
padding +=
|
|
(cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
|
|
maclen = csmac ? csmac->len : 0;
|
|
ssh2_pkt_ensure(pktout.length + padding + maclen);
|
|
pktout.data[4] = padding;
|
|
for (i = 0; i < padding; i++)
|
|
pktout.data[pktout.length + i] = random_byte();
|
|
PUT_32BIT(pktout.data, pktout.length + padding - 4);
|
|
if (csmac)
|
|
csmac->generate(pktout.data, pktout.length + padding,
|
|
outgoing_sequence);
|
|
outgoing_sequence++; /* whether or not we MACed */
|
|
|
|
#ifdef DUMP_PACKETS
|
|
debug(("Sending packet len=%d\n", pktout.length + padding));
|
|
dmemdump(pktout.data, pktout.length + padding);
|
|
#endif
|
|
|
|
if (cscipher)
|
|
cscipher->encrypt(pktout.data, pktout.length + padding);
|
|
|
|
/* Ready-to-send packet starts at pktout.data. We return length. */
|
|
return pktout.length + padding + maclen;
|
|
}
|
|
|
|
/*
|
|
* Construct and send an SSH2 packet immediately.
|
|
*/
|
|
static void ssh2_pkt_send(void)
|
|
{
|
|
int len;
|
|
int backlog;
|
|
len = ssh2_pkt_construct();
|
|
backlog = sk_write(s, pktout.data, len);
|
|
if (backlog > SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(1, backlog);
|
|
}
|
|
|
|
/*
|
|
* Construct an SSH2 packet and add it to a deferred data block.
|
|
* Useful for sending multiple packets in a single sk_write() call,
|
|
* to prevent a traffic-analysing listener from being able to work
|
|
* out the length of any particular packet (such as the password
|
|
* packet).
|
|
*
|
|
* Note that because SSH2 sequence-numbers its packets, this can
|
|
* NOT be used as an m4-style `defer' allowing packets to be
|
|
* constructed in one order and sent in another.
|
|
*/
|
|
static void ssh2_pkt_defer(void)
|
|
{
|
|
int len = ssh2_pkt_construct();
|
|
if (deferred_len + len > deferred_size) {
|
|
deferred_size = deferred_len + len + 128;
|
|
deferred_send_data = srealloc(deferred_send_data, deferred_size);
|
|
}
|
|
memcpy(deferred_send_data + deferred_len, pktout.data, len);
|
|
deferred_len += len;
|
|
}
|
|
|
|
/*
|
|
* Send the whole deferred data block constructed by
|
|
* ssh2_pkt_defer() or SSH1's defer_packet().
|
|
*/
|
|
static void ssh_pkt_defersend(void)
|
|
{
|
|
int backlog;
|
|
backlog = sk_write(s, deferred_send_data, deferred_len);
|
|
deferred_len = deferred_size = 0;
|
|
sfree(deferred_send_data);
|
|
deferred_send_data = NULL;
|
|
if (backlog > SSH_MAX_BACKLOG)
|
|
ssh_throttle_all(1, backlog);
|
|
}
|
|
|
|
#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 sha_mpint(SHA_State * s, Bignum b)
|
|
{
|
|
unsigned char *p;
|
|
int len;
|
|
p = ssh2_mpint_fmt(b, &len);
|
|
sha_string(s, p, len);
|
|
sfree(p);
|
|
}
|
|
|
|
/*
|
|
* SSH2 packet decode functions.
|
|
*/
|
|
static unsigned long ssh2_pkt_getuint32(void)
|
|
{
|
|
unsigned long value;
|
|
if (pktin.length - pktin.savedpos < 4)
|
|
return 0; /* arrgh, no way to decline (FIXME?) */
|
|
value = GET_32BIT(pktin.data + pktin.savedpos);
|
|
pktin.savedpos += 4;
|
|
return value;
|
|
}
|
|
static int ssh2_pkt_getbool(void)
|
|
{
|
|
unsigned long value;
|
|
if (pktin.length - pktin.savedpos < 1)
|
|
return 0; /* arrgh, no way to decline (FIXME?) */
|
|
value = pktin.data[pktin.savedpos] != 0;
|
|
pktin.savedpos++;
|
|
return value;
|
|
}
|
|
static void ssh2_pkt_getstring(char **p, int *length)
|
|
{
|
|
*p = NULL;
|
|
if (pktin.length - pktin.savedpos < 4)
|
|
return;
|
|
*length = GET_32BIT(pktin.data + pktin.savedpos);
|
|
pktin.savedpos += 4;
|
|
if (pktin.length - pktin.savedpos < *length)
|
|
return;
|
|
*p = pktin.data + pktin.savedpos;
|
|
pktin.savedpos += *length;
|
|
}
|
|
static Bignum ssh2_pkt_getmp(void)
|
|
{
|
|
char *p;
|
|
int length;
|
|
Bignum b;
|
|
|
|
ssh2_pkt_getstring(&p, &length);
|
|
if (!p)
|
|
return NULL;
|
|
if (p[0] & 0x80) {
|
|
bombout(("internal error: Can't handle negative mpints"));
|
|
return NULL;
|
|
}
|
|
b = bignum_from_bytes(p, length);
|
|
return b;
|
|
}
|
|
|
|
/*
|
|
* Examine the remote side's version string and compare it against
|
|
* a list of known buggy implementations.
|
|
*/
|
|
static void ssh_detect_bugs(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;
|
|
|
|
if (!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")) {
|
|
/*
|
|
* 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 SSH1 ignore bug");
|
|
}
|
|
|
|
if (!strcmp(imp, "Cisco-1.25")) {
|
|
/*
|
|
* 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 SSH1 password");
|
|
}
|
|
|
|
if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
|
|
!strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
|
|
!strncmp(imp, "2.1 ", 4)) {
|
|
/*
|
|
* These versions have the HMAC bug.
|
|
*/
|
|
ssh_remote_bugs |= BUG_SSH2_HMAC;
|
|
logevent("We believe remote version has SSH2 HMAC bug");
|
|
}
|
|
}
|
|
|
|
static int do_ssh_init(unsigned char c)
|
|
{
|
|
static int vslen;
|
|
static char version[10];
|
|
static char *vstring;
|
|
static int vstrsize;
|
|
static char *vlog;
|
|
static int i;
|
|
|
|
crBegin;
|
|
|
|
/* Search for the string "SSH-" in the input. */
|
|
i = 0;
|
|
while (1) {
|
|
static const int transS[] = { 1, 2, 2, 1 };
|
|
static const int transH[] = { 0, 0, 3, 0 };
|
|
static const int transminus[] = { 0, 0, 0, -1 };
|
|
if (c == 'S')
|
|
i = transS[i];
|
|
else if (c == 'H')
|
|
i = transH[i];
|
|
else if (c == '-')
|
|
i = transminus[i];
|
|
else
|
|
i = 0;
|
|
if (i < 0)
|
|
break;
|
|
crReturn(1); /* get another character */
|
|
}
|
|
|
|
vstrsize = 16;
|
|
vstring = smalloc(vstrsize);
|
|
strcpy(vstring, "SSH-");
|
|
vslen = 4;
|
|
i = 0;
|
|
while (1) {
|
|
crReturn(1); /* get another char */
|
|
if (vslen >= vstrsize - 1) {
|
|
vstrsize += 16;
|
|
vstring = srealloc(vstring, vstrsize);
|
|
}
|
|
vstring[vslen++] = c;
|
|
if (i >= 0) {
|
|
if (c == '-') {
|
|
version[i] = '\0';
|
|
i = -1;
|
|
} else if (i < sizeof(version) - 1)
|
|
version[i++] = c;
|
|
} else if (c == '\n')
|
|
break;
|
|
}
|
|
|
|
ssh_agentfwd_enabled = FALSE;
|
|
rdpkt2_state.incoming_sequence = 0;
|
|
|
|
vstring[vslen] = 0;
|
|
vlog = smalloc(20 + vslen);
|
|
vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
|
|
sprintf(vlog, "Server version: %s", vstring);
|
|
logevent(vlog);
|
|
ssh_detect_bugs(vstring);
|
|
sfree(vlog);
|
|
|
|
/*
|
|
* Server version "1.99" means we can choose whether we use v1
|
|
* or v2 protocol. Choice is based on cfg.sshprot.
|
|
*/
|
|
if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
|
|
/*
|
|
* This is a v2 server. Begin v2 protocol.
|
|
*/
|
|
char verstring[80], vlog[100];
|
|
sprintf(verstring, "SSH-2.0-%s", sshver);
|
|
SHA_Init(&exhashbase);
|
|
/*
|
|
* Hash our version string and their version string.
|
|
*/
|
|
sha_string(&exhashbase, verstring, strlen(verstring));
|
|
sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
|
|
sprintf(vlog, "We claim version: %s", verstring);
|
|
logevent(vlog);
|
|
strcat(verstring, "\n");
|
|
logevent("Using SSH protocol version 2");
|
|
sk_write(s, verstring, strlen(verstring));
|
|
ssh_protocol = ssh2_protocol;
|
|
ssh_version = 2;
|
|
s_rdpkt = ssh2_rdpkt;
|
|
} else {
|
|
/*
|
|
* This is a v1 server. Begin v1 protocol.
|
|
*/
|
|
char verstring[80], vlog[100];
|
|
sprintf(verstring, "SSH-%s-%s",
|
|
(ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
|
|
sshver);
|
|
sprintf(vlog, "We claim version: %s", verstring);
|
|
logevent(vlog);
|
|
strcat(verstring, "\n");
|
|
logevent("Using SSH protocol version 1");
|
|
sk_write(s, verstring, strlen(verstring));
|
|
ssh_protocol = ssh1_protocol;
|
|
ssh_version = 1;
|
|
s_rdpkt = ssh1_rdpkt;
|
|
}
|
|
ssh_state = SSH_STATE_BEFORE_SIZE;
|
|
|
|
sfree(vstring);
|
|
|
|
crFinish(0);
|
|
}
|
|
|
|
static void ssh_gotdata(unsigned char *data, int datalen)
|
|
{
|
|
crBegin;
|
|
|
|
/*
|
|
* 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;
|
|
if (datalen == 0)
|
|
crReturnV; /* more data please */
|
|
ret = do_ssh_init(*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.
|
|
*/
|
|
if (datalen == 0)
|
|
crReturnV;
|
|
while (1) {
|
|
while (datalen > 0) {
|
|
if (s_rdpkt(&data, &datalen) == 0) {
|
|
if (ssh_state == SSH_STATE_CLOSED) {
|
|
return;
|
|
}
|
|
ssh_protocol(NULL, 0, 1);
|
|
if (ssh_state == SSH_STATE_CLOSED) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
crReturnV;
|
|
}
|
|
crFinishV;
|
|
}
|
|
|
|
static int ssh_closing(Plug plug, char *error_msg, int error_code,
|
|
int calling_back)
|
|
{
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
if (s) {
|
|
sk_close(s);
|
|
s = NULL;
|
|
}
|
|
if (error_msg) {
|
|
/* A socket error has occurred. */
|
|
connection_fatal(error_msg);
|
|
} else {
|
|
/* Otherwise, the remote side closed the connection normally. */
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int ssh_receive(Plug plug, int urgent, char *data, int len)
|
|
{
|
|
ssh_gotdata(data, len);
|
|
if (ssh_state == SSH_STATE_CLOSED) {
|
|
if (s) {
|
|
sk_close(s);
|
|
s = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void ssh_sent(Plug plug, int bufsize)
|
|
{
|
|
/*
|
|
* 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(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 char *connect_to_host(char *host, int port, char **realhost)
|
|
{
|
|
static struct plug_function_table fn_table = {
|
|
ssh_closing,
|
|
ssh_receive,
|
|
ssh_sent,
|
|
NULL
|
|
}, *fn_table_ptr = &fn_table;
|
|
|
|
SockAddr addr;
|
|
char *err;
|
|
#ifdef FWHACK
|
|
char *FWhost;
|
|
int FWport;
|
|
#endif
|
|
|
|
savedhost = smalloc(1 + strlen(host));
|
|
if (!savedhost)
|
|
fatalbox("Out of memory");
|
|
strcpy(savedhost, host);
|
|
|
|
if (port < 0)
|
|
port = 22; /* default ssh port */
|
|
savedport = port;
|
|
|
|
#ifdef FWHACK
|
|
FWhost = host;
|
|
FWport = port;
|
|
host = FWSTR;
|
|
port = 23;
|
|
#endif
|
|
|
|
/*
|
|
* Try to find host.
|
|
*/
|
|
{
|
|
char buf[200];
|
|
sprintf(buf, "Looking up host \"%.170s\"", host);
|
|
logevent(buf);
|
|
}
|
|
addr = sk_namelookup(host, realhost);
|
|
if ((err = sk_addr_error(addr)))
|
|
return err;
|
|
|
|
#ifdef FWHACK
|
|
*realhost = strdup(FWhost);
|
|
#endif
|
|
|
|
/*
|
|
* Open socket.
|
|
*/
|
|
{
|
|
char buf[200], addrbuf[100];
|
|
sk_getaddr(addr, addrbuf, 100);
|
|
sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
|
|
logevent(buf);
|
|
}
|
|
s = sk_new(addr, port, 0, 1, &fn_table_ptr);
|
|
if ((err = sk_socket_error(s)))
|
|
return err;
|
|
|
|
#ifdef FWHACK
|
|
sk_write(s, "connect ", 8);
|
|
sk_write(s, FWhost, strlen(FWhost));
|
|
{
|
|
char buf[20];
|
|
sprintf(buf, " %d\n", FWport);
|
|
sk_write(s, buf, strlen(buf));
|
|
}
|
|
#endif
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Throttle or unthrottle the SSH connection.
|
|
*/
|
|
static void ssh1_throttle(int adjust)
|
|
{
|
|
int old_count = ssh1_throttle_count;
|
|
ssh1_throttle_count += adjust;
|
|
assert(ssh1_throttle_count >= 0);
|
|
if (ssh1_throttle_count && !old_count) {
|
|
sk_set_frozen(s, 1);
|
|
} else if (!ssh1_throttle_count && old_count) {
|
|
sk_set_frozen(s, 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Throttle or unthrottle _all_ local data streams (for when sends
|
|
* on the SSH connection itself back up).
|
|
*/
|
|
static void ssh_throttle_all(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.x11.s, enable);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle the key exchange and user authentication phases.
|
|
*/
|
|
static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
|
|
{
|
|
int i, j;
|
|
static int len;
|
|
static unsigned char *rsabuf, *keystr1, *keystr2;
|
|
unsigned char cookie[8];
|
|
struct RSAKey servkey, hostkey;
|
|
struct MD5Context md5c;
|
|
static unsigned long supported_ciphers_mask, supported_auths_mask;
|
|
static int tried_publickey;
|
|
static int tis_auth_refused, ccard_auth_refused;
|
|
static unsigned char session_id[16];
|
|
static int cipher_type;
|
|
static char username[100];
|
|
|
|
crBegin;
|
|
|
|
if (!ispkt)
|
|
crWaitUntil(ispkt);
|
|
|
|
if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
|
|
bombout(("Public key packet not received"));
|
|
crReturn(0);
|
|
}
|
|
|
|
logevent("Received public keys");
|
|
|
|
memcpy(cookie, pktin.body, 8);
|
|
|
|
i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
|
|
j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 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);
|
|
}
|
|
|
|
ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
|
|
supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
|
|
supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
|
|
|
|
ssh1_local_protoflags =
|
|
ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
|
|
ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, keystr2, hostkey.bytes);
|
|
MD5Update(&md5c, keystr1, servkey.bytes);
|
|
MD5Update(&md5c, pktin.body, 8);
|
|
MD5Final(session_id, &md5c);
|
|
|
|
for (i = 0; i < 32; i++)
|
|
session_key[i] = random_byte();
|
|
|
|
len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
|
|
|
|
rsabuf = smalloc(len);
|
|
if (!rsabuf)
|
|
fatalbox("Out of memory");
|
|
|
|
/*
|
|
* Verify the host key.
|
|
*/
|
|
{
|
|
/*
|
|
* First format the key into a string.
|
|
*/
|
|
int len = rsastr_len(&hostkey);
|
|
char fingerprint[100];
|
|
char *keystr = smalloc(len);
|
|
if (!keystr)
|
|
fatalbox("Out of memory");
|
|
rsastr_fmt(keystr, &hostkey);
|
|
rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
|
|
verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
|
|
fingerprint);
|
|
sfree(keystr);
|
|
}
|
|
|
|
for (i = 0; i < 32; i++) {
|
|
rsabuf[i] = session_key[i];
|
|
if (i < 16)
|
|
rsabuf[i] ^= session_id[i];
|
|
}
|
|
|
|
if (hostkey.bytes > servkey.bytes) {
|
|
rsaencrypt(rsabuf, 32, &servkey);
|
|
rsaencrypt(rsabuf, servkey.bytes, &hostkey);
|
|
} else {
|
|
rsaencrypt(rsabuf, 32, &hostkey);
|
|
rsaencrypt(rsabuf, hostkey.bytes, &servkey);
|
|
}
|
|
|
|
logevent("Encrypted session key");
|
|
|
|
{
|
|
int cipher_chosen = 0, warn = 0;
|
|
char *cipher_string = NULL;
|
|
for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
|
|
int next_cipher = 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 SSH1, skipping");
|
|
} else {
|
|
switch (next_cipher) {
|
|
case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
|
|
cipher_string = "3DES"; break;
|
|
case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
|
|
cipher_string = "Blowfish"; break;
|
|
case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
|
|
cipher_string = "single-DES"; break;
|
|
}
|
|
if (supported_ciphers_mask & (1 << cipher_type))
|
|
cipher_chosen = 1;
|
|
}
|
|
}
|
|
if (!cipher_chosen) {
|
|
if ((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"));
|
|
crReturn(0);
|
|
}
|
|
|
|
/* Warn about chosen cipher if necessary. */
|
|
if (warn)
|
|
askcipher(cipher_string, 0);
|
|
}
|
|
|
|
switch (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(SSH1_CMSG_SESSION_KEY,
|
|
PKT_CHAR, cipher_type,
|
|
PKT_DATA, cookie, 8,
|
|
PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
|
|
PKT_DATA, rsabuf, len,
|
|
PKT_INT, ssh1_local_protoflags, PKT_END);
|
|
|
|
logevent("Trying to enable encryption...");
|
|
|
|
sfree(rsabuf);
|
|
|
|
cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
|
|
cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
|
|
cipher->sesskey(session_key);
|
|
|
|
crWaitUntil(ispkt);
|
|
|
|
if (pktin.type != SSH1_SMSG_SUCCESS) {
|
|
bombout(("Encryption not successfully enabled"));
|
|
crReturn(0);
|
|
}
|
|
|
|
logevent("Successfully started encryption");
|
|
|
|
fflush(stdout);
|
|
{
|
|
static int pos = 0;
|
|
static char c;
|
|
if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
|
|
if (ssh_get_line) {
|
|
if (!ssh_get_line("login as: ",
|
|
username, sizeof(username), FALSE)) {
|
|
/*
|
|
* get_line failed to get a username.
|
|
* Terminate.
|
|
*/
|
|
logevent("No username provided. Abandoning session.");
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturn(1);
|
|
}
|
|
} else {
|
|
c_write_str("login as: ");
|
|
ssh_send_ok = 1;
|
|
while (pos >= 0) {
|
|
crWaitUntil(!ispkt);
|
|
while (inlen--)
|
|
switch (c = *in++) {
|
|
case 10:
|
|
case 13:
|
|
username[pos] = 0;
|
|
pos = -1;
|
|
break;
|
|
case 8:
|
|
case 127:
|
|
if (pos > 0) {
|
|
c_write_str("\b \b");
|
|
pos--;
|
|
}
|
|
break;
|
|
case 21:
|
|
case 27:
|
|
while (pos > 0) {
|
|
c_write_str("\b \b");
|
|
pos--;
|
|
}
|
|
break;
|
|
case 3:
|
|
case 4:
|
|
random_save_seed();
|
|
exit(0);
|
|
break;
|
|
default:
|
|
if (((c >= ' ' && c <= '~') ||
|
|
((unsigned char) c >= 160))
|
|
&& pos < sizeof(username)-1) {
|
|
username[pos++] = c;
|
|
c_write(&c, 1);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
c_write_str("\r\n");
|
|
username[strcspn(username, "\n\r")] = '\0';
|
|
}
|
|
} else {
|
|
strncpy(username, cfg.username, 99);
|
|
username[99] = '\0';
|
|
}
|
|
|
|
send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
|
|
{
|
|
char userlog[22 + sizeof(username)];
|
|
sprintf(userlog, "Sent username \"%s\"", username);
|
|
logevent(userlog);
|
|
if (flags & FLAG_INTERACTIVE &&
|
|
(!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
|
|
strcat(userlog, "\r\n");
|
|
c_write_str(userlog);
|
|
}
|
|
}
|
|
}
|
|
|
|
crWaitUntil(ispkt);
|
|
|
|
tried_publickey = 0;
|
|
tis_auth_refused = ccard_auth_refused = 0;
|
|
|
|
while (pktin.type == SSH1_SMSG_FAILURE) {
|
|
static char password[100];
|
|
static char prompt[200];
|
|
static int pos;
|
|
static char c;
|
|
static int pwpkt_type;
|
|
pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
|
|
|
|
if (agent_exists()) {
|
|
/*
|
|
* Attempt RSA authentication using Pageant.
|
|
*/
|
|
static unsigned char request[5], *response, *p;
|
|
static int responselen;
|
|
static int i, nkeys;
|
|
static int authed = FALSE;
|
|
void *r;
|
|
|
|
logevent("Pageant is running. Requesting keys.");
|
|
|
|
/* Request the keys held by the agent. */
|
|
PUT_32BIT(request, 1);
|
|
request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
|
|
agent_query(request, 5, &r, &responselen);
|
|
response = (unsigned char *) r;
|
|
if (response && responselen >= 5 &&
|
|
response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
|
|
p = response + 5;
|
|
nkeys = GET_32BIT(p);
|
|
p += 4;
|
|
{
|
|
char buf[64];
|
|
sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
|
|
logevent(buf);
|
|
}
|
|
for (i = 0; i < nkeys; i++) {
|
|
static struct RSAKey key;
|
|
static Bignum challenge;
|
|
static char *commentp;
|
|
static int commentlen;
|
|
|
|
{
|
|
char buf[64];
|
|
sprintf(buf, "Trying Pageant key #%d", i);
|
|
logevent(buf);
|
|
}
|
|
p += 4;
|
|
p += ssh1_read_bignum(p, &key.exponent);
|
|
p += ssh1_read_bignum(p, &key.modulus);
|
|
commentlen = GET_32BIT(p);
|
|
p += 4;
|
|
commentp = p;
|
|
p += commentlen;
|
|
send_packet(SSH1_CMSG_AUTH_RSA,
|
|
PKT_BIGNUM, key.modulus, PKT_END);
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
|
|
logevent("Key refused");
|
|
continue;
|
|
}
|
|
logevent("Received RSA challenge");
|
|
ssh1_read_bignum(pktin.body, &challenge);
|
|
{
|
|
char *agentreq, *q, *ret;
|
|
void *vret;
|
|
int len, retlen;
|
|
len = 1 + 4; /* message type, bit count */
|
|
len += ssh1_bignum_length(key.exponent);
|
|
len += ssh1_bignum_length(key.modulus);
|
|
len += ssh1_bignum_length(challenge);
|
|
len += 16; /* session id */
|
|
len += 4; /* response format */
|
|
agentreq = smalloc(4 + len);
|
|
PUT_32BIT(agentreq, len);
|
|
q = agentreq + 4;
|
|
*q++ = SSH1_AGENTC_RSA_CHALLENGE;
|
|
PUT_32BIT(q, bignum_bitcount(key.modulus));
|
|
q += 4;
|
|
q += ssh1_write_bignum(q, key.exponent);
|
|
q += ssh1_write_bignum(q, key.modulus);
|
|
q += ssh1_write_bignum(q, challenge);
|
|
memcpy(q, session_id, 16);
|
|
q += 16;
|
|
PUT_32BIT(q, 1); /* response format */
|
|
agent_query(agentreq, len + 4, &vret, &retlen);
|
|
ret = vret;
|
|
sfree(agentreq);
|
|
if (ret) {
|
|
if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
|
|
logevent("Sending Pageant's response");
|
|
send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
|
|
PKT_DATA, ret + 5, 16,
|
|
PKT_END);
|
|
sfree(ret);
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type == SSH1_SMSG_SUCCESS) {
|
|
logevent
|
|
("Pageant's response accepted");
|
|
if (flags & FLAG_VERBOSE) {
|
|
c_write_str
|
|
("Authenticated using RSA key \"");
|
|
c_write(commentp, commentlen);
|
|
c_write_str("\" from agent\r\n");
|
|
}
|
|
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(key.exponent);
|
|
freebn(key.modulus);
|
|
freebn(challenge);
|
|
if (authed)
|
|
break;
|
|
}
|
|
}
|
|
if (authed)
|
|
break;
|
|
}
|
|
if (*cfg.keyfile && !tried_publickey)
|
|
pwpkt_type = SSH1_CMSG_AUTH_RSA;
|
|
|
|
if (cfg.try_tis_auth &&
|
|
(supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
|
|
!tis_auth_refused) {
|
|
pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
|
|
logevent("Requested TIS authentication");
|
|
send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
|
|
logevent("TIS authentication declined");
|
|
if (flags & FLAG_INTERACTIVE)
|
|
c_write_str("TIS authentication refused.\r\n");
|
|
tis_auth_refused = 1;
|
|
continue;
|
|
} else {
|
|
int challengelen = ((pktin.body[0] << 24) |
|
|
(pktin.body[1] << 16) |
|
|
(pktin.body[2] << 8) |
|
|
(pktin.body[3]));
|
|
logevent("Received TIS challenge");
|
|
if (challengelen > sizeof(prompt) - 1)
|
|
challengelen = sizeof(prompt) - 1; /* prevent overrun */
|
|
memcpy(prompt, pktin.body + 4, challengelen);
|
|
/* Prompt heuristic comes from OpenSSH */
|
|
strncpy(prompt + challengelen,
|
|
memchr(prompt, '\n', challengelen) ?
|
|
"": "\r\nResponse: ",
|
|
(sizeof prompt) - challengelen);
|
|
prompt[(sizeof prompt) - 1] = '\0';
|
|
}
|
|
}
|
|
if (cfg.try_tis_auth &&
|
|
(supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
|
|
!ccard_auth_refused) {
|
|
pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
|
|
logevent("Requested CryptoCard authentication");
|
|
send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
|
|
logevent("CryptoCard authentication declined");
|
|
c_write_str("CryptoCard authentication refused.\r\n");
|
|
ccard_auth_refused = 1;
|
|
continue;
|
|
} else {
|
|
int challengelen = ((pktin.body[0] << 24) |
|
|
(pktin.body[1] << 16) |
|
|
(pktin.body[2] << 8) |
|
|
(pktin.body[3]));
|
|
logevent("Received CryptoCard challenge");
|
|
if (challengelen > sizeof(prompt) - 1)
|
|
challengelen = sizeof(prompt) - 1; /* prevent overrun */
|
|
memcpy(prompt, pktin.body + 4, challengelen);
|
|
strncpy(prompt + challengelen,
|
|
memchr(prompt, '\n', challengelen) ?
|
|
"" : "\r\nResponse: ",
|
|
sizeof(prompt) - challengelen);
|
|
prompt[sizeof(prompt) - 1] = '\0';
|
|
}
|
|
}
|
|
if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
|
|
sprintf(prompt, "%.90s@%.90s's password: ",
|
|
username, savedhost);
|
|
}
|
|
if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
|
|
char *comment = NULL;
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str("Trying public key authentication.\r\n");
|
|
if (!rsakey_encrypted(cfg.keyfile, &comment)) {
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str("No passphrase required.\r\n");
|
|
goto tryauth;
|
|
}
|
|
sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
|
|
sfree(comment);
|
|
}
|
|
|
|
/*
|
|
* Show password prompt, having first obtained it via a TIS
|
|
* or CryptoCard exchange if we're doing TIS or CryptoCard
|
|
* authentication.
|
|
*/
|
|
if (ssh_get_line) {
|
|
if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
|
|
/*
|
|
* get_line failed to get a password (for example
|
|
* because one was supplied on the command line
|
|
* which has already failed to work). Terminate.
|
|
*/
|
|
send_packet(SSH1_MSG_DISCONNECT,
|
|
PKT_STR, "No more passwords available to try",
|
|
PKT_END);
|
|
connection_fatal("Unable to authenticate");
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturn(1);
|
|
}
|
|
} else {
|
|
/* Prompt may have come from server. We've munged it a bit, so
|
|
* we know it to be zero-terminated at least once. */
|
|
c_write_untrusted(prompt, strlen(prompt));
|
|
pos = 0;
|
|
ssh_send_ok = 1;
|
|
while (pos >= 0) {
|
|
crWaitUntil(!ispkt);
|
|
while (inlen--)
|
|
switch (c = *in++) {
|
|
case 10:
|
|
case 13:
|
|
password[pos] = 0;
|
|
pos = -1;
|
|
break;
|
|
case 8:
|
|
case 127:
|
|
if (pos > 0)
|
|
pos--;
|
|
break;
|
|
case 21:
|
|
case 27:
|
|
pos = 0;
|
|
break;
|
|
case 3:
|
|
case 4:
|
|
random_save_seed();
|
|
exit(0);
|
|
break;
|
|
default:
|
|
if (pos < sizeof(password)-1)
|
|
password[pos++] = c;
|
|
break;
|
|
}
|
|
}
|
|
c_write_str("\r\n");
|
|
}
|
|
|
|
tryauth:
|
|
if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
|
|
/*
|
|
* Try public key authentication with the specified
|
|
* key file.
|
|
*/
|
|
static struct RSAKey pubkey;
|
|
static Bignum challenge, response;
|
|
static int i;
|
|
static unsigned char buffer[32];
|
|
|
|
tried_publickey = 1;
|
|
i = loadrsakey(cfg.keyfile, &pubkey, password);
|
|
if (i == 0) {
|
|
c_write_str("Couldn't load private key from ");
|
|
c_write_str(cfg.keyfile);
|
|
c_write_str(".\r\n");
|
|
continue; /* go and try password */
|
|
}
|
|
if (i == -1) {
|
|
c_write_str("Wrong passphrase.\r\n");
|
|
tried_publickey = 0;
|
|
continue; /* try again */
|
|
}
|
|
|
|
/*
|
|
* Send a public key attempt.
|
|
*/
|
|
send_packet(SSH1_CMSG_AUTH_RSA,
|
|
PKT_BIGNUM, pubkey.modulus, PKT_END);
|
|
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
c_write_str("Server refused our public key.\r\n");
|
|
continue; /* go and try password */
|
|
}
|
|
if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
|
|
bombout(("Bizarre response to offer of public key"));
|
|
crReturn(0);
|
|
}
|
|
ssh1_read_bignum(pktin.body, &challenge);
|
|
response = rsadecrypt(challenge, &pubkey);
|
|
freebn(pubkey.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, session_id, 16);
|
|
MD5Final(buffer, &md5c);
|
|
|
|
send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
|
|
PKT_DATA, buffer, 16, PKT_END);
|
|
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str
|
|
("Failed to authenticate with our public key.\r\n");
|
|
continue; /* go and try password */
|
|
} else if (pktin.type != SSH1_SMSG_SUCCESS) {
|
|
bombout(
|
|
("Bizarre response to RSA authentication response"));
|
|
crReturn(0);
|
|
}
|
|
|
|
break; /* we're through! */
|
|
} else {
|
|
if (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 (the old 1.2.18 through 1.2.22)
|
|
* can't deal with SSH1_MSG_IGNORE. 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.
|
|
*
|
|
* One server (a Cisco one) can deal with neither
|
|
* SSH1_MSG_IGNORE _nor_ a padded password string.
|
|
* For this server we are left with no defences
|
|
* against password length sniffing.
|
|
*/
|
|
if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
|
|
/*
|
|
* The server can deal with SSH1_MSG_IGNORE, so
|
|
* we can use the primary defence.
|
|
*/
|
|
int bottom, top, pwlen, i;
|
|
char *randomstr;
|
|
|
|
pwlen = strlen(password);
|
|
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 = smalloc(top + 1);
|
|
|
|
for (i = bottom; i <= top; i++) {
|
|
if (i == pwlen)
|
|
defer_packet(pwpkt_type, PKT_STR, password,
|
|
PKT_END);
|
|
else {
|
|
for (j = 0; j < i; j++) {
|
|
do {
|
|
randomstr[j] = random_byte();
|
|
} while (randomstr[j] == '\0');
|
|
}
|
|
randomstr[i] = '\0';
|
|
defer_packet(SSH1_MSG_IGNORE,
|
|
PKT_STR, randomstr, PKT_END);
|
|
}
|
|
}
|
|
logevent("Sending password with camouflage packets");
|
|
ssh_pkt_defersend();
|
|
}
|
|
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 *s;
|
|
int len;
|
|
|
|
len = strlen(password);
|
|
if (len < sizeof(string)) {
|
|
s = string;
|
|
strcpy(string, password);
|
|
len++; /* cover the zero byte */
|
|
while (len < sizeof(string)) {
|
|
string[len++] = (char) random_byte();
|
|
}
|
|
} else {
|
|
s = password;
|
|
}
|
|
logevent("Sending length-padded password");
|
|
send_packet(pwpkt_type, PKT_INT, len,
|
|
PKT_DATA, s, len, PKT_END);
|
|
} else {
|
|
/*
|
|
* The server has _both_
|
|
* BUG_CHOKES_ON_SSH1_IGNORE and
|
|
* BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
|
|
* therefore nothing we can do.
|
|
*/
|
|
int len;
|
|
len = strlen(password);
|
|
logevent("Sending unpadded password");
|
|
send_packet(pwpkt_type, PKT_INT, len,
|
|
PKT_DATA, password, len, PKT_END);
|
|
}
|
|
} else {
|
|
send_packet(pwpkt_type, PKT_STR, password, PKT_END);
|
|
}
|
|
}
|
|
logevent("Sent password");
|
|
memset(password, 0, strlen(password));
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
if (flags & FLAG_VERBOSE)
|
|
c_write_str("Access denied\r\n");
|
|
logevent("Authentication refused");
|
|
} else if (pktin.type == SSH1_MSG_DISCONNECT) {
|
|
logevent("Received disconnect request");
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturn(1);
|
|
} else if (pktin.type != SSH1_SMSG_SUCCESS) {
|
|
bombout(("Strange packet received, type %d", pktin.type));
|
|
crReturn(0);
|
|
}
|
|
}
|
|
|
|
logevent("Authentication successful");
|
|
|
|
crFinish(1);
|
|
}
|
|
|
|
void sshfwd_close(struct ssh_channel *c)
|
|
{
|
|
if (c && !c->closes) {
|
|
/*
|
|
* If the channel's remoteid is -1, 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->remoteid != -1) {
|
|
if (ssh_version == 1) {
|
|
send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
|
|
PKT_END);
|
|
} else {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_send();
|
|
}
|
|
}
|
|
c->closes = 1;
|
|
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)
|
|
{
|
|
if (ssh_version == 1) {
|
|
send_packet(SSH1_MSG_CHANNEL_DATA,
|
|
PKT_INT, c->remoteid,
|
|
PKT_INT, len, PKT_DATA, buf, len, PKT_END);
|
|
/*
|
|
* In SSH1 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)
|
|
{
|
|
if (ssh_version == 1) {
|
|
if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
|
|
c->v.v1.throttling = 0;
|
|
ssh1_throttle(-1);
|
|
}
|
|
} else {
|
|
ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
|
|
}
|
|
}
|
|
|
|
static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
|
|
{
|
|
crBegin;
|
|
|
|
random_init();
|
|
|
|
while (!do_ssh1_login(in, inlen, ispkt)) {
|
|
crReturnV;
|
|
}
|
|
if (ssh_state == SSH_STATE_CLOSED)
|
|
crReturnV;
|
|
|
|
if (cfg.agentfwd && agent_exists()) {
|
|
logevent("Requesting agent forwarding");
|
|
send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
|
|
do {
|
|
crReturnV;
|
|
} while (!ispkt);
|
|
if (pktin.type != SSH1_SMSG_SUCCESS
|
|
&& pktin.type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crReturnV;
|
|
} else if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
logevent("Agent forwarding refused");
|
|
} else {
|
|
logevent("Agent forwarding enabled");
|
|
ssh_agentfwd_enabled = TRUE;
|
|
}
|
|
}
|
|
|
|
if (cfg.x11_forward) {
|
|
char proto[20], data[64];
|
|
logevent("Requesting X11 forwarding");
|
|
x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
|
|
if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
|
|
send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
|
|
PKT_STR, proto, PKT_STR, data,
|
|
PKT_INT, 0, PKT_END);
|
|
} else {
|
|
send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
|
|
PKT_STR, proto, PKT_STR, data, PKT_END);
|
|
}
|
|
do {
|
|
crReturnV;
|
|
} while (!ispkt);
|
|
if (pktin.type != SSH1_SMSG_SUCCESS
|
|
&& pktin.type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crReturnV;
|
|
} else if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
logevent("X11 forwarding refused");
|
|
} else {
|
|
logevent("X11 forwarding enabled");
|
|
ssh_X11_fwd_enabled = TRUE;
|
|
}
|
|
}
|
|
|
|
{
|
|
char type, *e;
|
|
int n;
|
|
int sport,dport;
|
|
char sports[256], dports[256], host[256];
|
|
char buf[1024];
|
|
|
|
ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
|
|
/* Add port forwardings. */
|
|
e = cfg.portfwd;
|
|
while (*e) {
|
|
type = *e++;
|
|
n = 0;
|
|
while (*e && *e != '\t')
|
|
sports[n++] = *e++;
|
|
sports[n] = 0;
|
|
if (*e == '\t')
|
|
e++;
|
|
n = 0;
|
|
while (*e && *e != ':')
|
|
host[n++] = *e++;
|
|
host[n] = 0;
|
|
if (*e == ':')
|
|
e++;
|
|
n = 0;
|
|
while (*e)
|
|
dports[n++] = *e++;
|
|
dports[n] = 0;
|
|
e++;
|
|
dport = atoi(dports);
|
|
sport = atoi(sports);
|
|
if (sport && dport) {
|
|
if (type == 'L') {
|
|
pfd_addforward(host, dport, sport);
|
|
sprintf(buf, "Local port %d forwarding to %s:%d",
|
|
sport, host, dport);
|
|
logevent(buf);
|
|
} else {
|
|
struct ssh_rportfwd *pf;
|
|
pf = smalloc(sizeof(*pf));
|
|
strcpy(pf->dhost, host);
|
|
pf->dport = dport;
|
|
if (add234(ssh_rportfwds, pf) != pf) {
|
|
sprintf(buf,
|
|
"Duplicate remote port forwarding to %s:%d",
|
|
host, dport);
|
|
logevent(buf);
|
|
sfree(pf);
|
|
} else {
|
|
sprintf(buf, "Requesting remote port %d forward to %s:%d",
|
|
sport, host, dport);
|
|
logevent(buf);
|
|
send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
|
|
PKT_INT, sport,
|
|
PKT_STR, host,
|
|
PKT_INT, dport,
|
|
PKT_END);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!cfg.nopty) {
|
|
send_packet(SSH1_CMSG_REQUEST_PTY,
|
|
PKT_STR, cfg.termtype,
|
|
PKT_INT, rows, PKT_INT, cols,
|
|
PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
|
|
ssh_state = SSH_STATE_INTERMED;
|
|
do {
|
|
crReturnV;
|
|
} while (!ispkt);
|
|
if (pktin.type != SSH1_SMSG_SUCCESS
|
|
&& pktin.type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crReturnV;
|
|
} else if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
c_write_str("Server refused to allocate pty\r\n");
|
|
ssh_editing = ssh_echoing = 1;
|
|
}
|
|
logevent("Allocated pty");
|
|
} else {
|
|
ssh_editing = ssh_echoing = 1;
|
|
}
|
|
|
|
if (cfg.compression) {
|
|
send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
|
|
do {
|
|
crReturnV;
|
|
} while (!ispkt);
|
|
if (pktin.type != SSH1_SMSG_SUCCESS
|
|
&& pktin.type != SSH1_SMSG_FAILURE) {
|
|
bombout(("Protocol confusion"));
|
|
crReturnV;
|
|
} else if (pktin.type == SSH1_SMSG_FAILURE) {
|
|
c_write_str("Server refused to compress\r\n");
|
|
}
|
|
logevent("Started compression");
|
|
ssh1_compressing = TRUE;
|
|
zlib_compress_init();
|
|
zlib_decompress_init();
|
|
}
|
|
|
|
/*
|
|
* Start the shell or command.
|
|
*
|
|
* Special case: if the first-choice command is an SSH2
|
|
* subsystem (hence not usable here) and the second choice
|
|
* exists, we fall straight back to that.
|
|
*/
|
|
{
|
|
char *cmd = cfg.remote_cmd_ptr;
|
|
|
|
if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
|
|
cmd = cfg.remote_cmd_ptr2;
|
|
ssh_fallback_cmd = TRUE;
|
|
}
|
|
if (*cmd)
|
|
send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
|
|
else
|
|
send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
|
|
logevent("Started session");
|
|
}
|
|
|
|
ssh_state = SSH_STATE_SESSION;
|
|
if (size_needed)
|
|
ssh_size();
|
|
if (eof_needed)
|
|
ssh_special(TS_EOF);
|
|
|
|
ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
|
|
ssh_send_ok = 1;
|
|
ssh_channels = newtree234(ssh_channelcmp);
|
|
while (1) {
|
|
crReturnV;
|
|
if (ispkt) {
|
|
if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
|
|
pktin.type == SSH1_SMSG_STDERR_DATA) {
|
|
long len = GET_32BIT(pktin.body);
|
|
int bufsize =
|
|
from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
|
|
pktin.body + 4, len);
|
|
if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
|
|
ssh1_stdout_throttling = 1;
|
|
ssh1_throttle(+1);
|
|
}
|
|
} else if (pktin.type == SSH1_MSG_DISCONNECT) {
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
logevent("Received disconnect request");
|
|
crReturnV;
|
|
} else if (pktin.type == SSH1_SMSG_X11_OPEN) {
|
|
/* 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;
|
|
|
|
logevent("Received X11 connect request");
|
|
/* Refuse if X11 forwarding is disabled. */
|
|
if (!ssh_X11_fwd_enabled) {
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, GET_32BIT(pktin.body), PKT_END);
|
|
logevent("Rejected X11 connect request");
|
|
} else {
|
|
c = smalloc(sizeof(struct ssh_channel));
|
|
|
|
if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
|
|
logevent("opening X11 forward connection failed");
|
|
sfree(c);
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, GET_32BIT(pktin.body),
|
|
PKT_END);
|
|
} else {
|
|
logevent
|
|
("opening X11 forward connection succeeded");
|
|
c->remoteid = GET_32BIT(pktin.body);
|
|
c->localid = alloc_channel_id();
|
|
c->closes = 0;
|
|
c->v.v1.throttling = 0;
|
|
c->type = CHAN_X11; /* identify channel type */
|
|
add234(ssh_channels, c);
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
|
|
PKT_INT, c->remoteid, PKT_INT,
|
|
c->localid, PKT_END);
|
|
logevent("Opened X11 forward channel");
|
|
}
|
|
}
|
|
} else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
|
|
/* Remote side is trying to open a channel to talk to our
|
|
* agent. Give them back a local channel number. */
|
|
struct ssh_channel *c;
|
|
|
|
/* Refuse if agent forwarding is disabled. */
|
|
if (!ssh_agentfwd_enabled) {
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, GET_32BIT(pktin.body), PKT_END);
|
|
} else {
|
|
c = smalloc(sizeof(struct ssh_channel));
|
|
c->remoteid = GET_32BIT(pktin.body);
|
|
c->localid = alloc_channel_id();
|
|
c->closes = 0;
|
|
c->v.v1.throttling = 0;
|
|
c->type = CHAN_AGENT; /* identify channel type */
|
|
c->u.a.lensofar = 0;
|
|
add234(ssh_channels, c);
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
|
|
PKT_INT, c->remoteid, PKT_INT, c->localid,
|
|
PKT_END);
|
|
}
|
|
} else if (pktin.type == SSH1_MSG_PORT_OPEN) {
|
|
/* 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;
|
|
int hostsize, port;
|
|
char host[256], buf[1024];
|
|
char *p, *h, *e;
|
|
c = smalloc(sizeof(struct ssh_channel));
|
|
|
|
hostsize = GET_32BIT(pktin.body+4);
|
|
for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
|
|
if (h+1 < host+sizeof(host))
|
|
*h++ = *p;
|
|
p++;
|
|
}
|
|
*h = 0;
|
|
port = GET_32BIT(p);
|
|
|
|
strcpy(pf.dhost, host);
|
|
pf.dport = port;
|
|
|
|
if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
|
|
sprintf(buf, "Rejected remote port open request for %s:%d",
|
|
host, port);
|
|
logevent(buf);
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, GET_32BIT(pktin.body), PKT_END);
|
|
} else {
|
|
sprintf(buf, "Received remote port open request for %s:%d",
|
|
host, port);
|
|
logevent(buf);
|
|
e = pfd_newconnect(&c->u.pfd.s, host, port, c);
|
|
if (e != NULL) {
|
|
char buf[256];
|
|
sprintf(buf, "Port open failed: %s", e);
|
|
logevent(buf);
|
|
sfree(c);
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
|
|
PKT_INT, GET_32BIT(pktin.body),
|
|
PKT_END);
|
|
} else {
|
|
c->remoteid = GET_32BIT(pktin.body);
|
|
c->localid = alloc_channel_id();
|
|
c->closes = 0;
|
|
c->v.v1.throttling = 0;
|
|
c->type = CHAN_SOCKDATA; /* identify channel type */
|
|
add234(ssh_channels, c);
|
|
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
|
|
PKT_INT, c->remoteid, PKT_INT,
|
|
c->localid, PKT_END);
|
|
logevent("Forwarded port opened successfully");
|
|
}
|
|
}
|
|
|
|
} else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
|
|
unsigned int remoteid = GET_32BIT(pktin.body);
|
|
unsigned int localid = GET_32BIT(pktin.body+4);
|
|
struct ssh_channel *c;
|
|
|
|
c = find234(ssh_channels, &remoteid, ssh_channelfind);
|
|
if (c && c->type == CHAN_SOCKDATA_DORMANT) {
|
|
c->remoteid = localid;
|
|
c->type = CHAN_SOCKDATA;
|
|
c->v.v1.throttling = 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(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
|
|
PKT_END);
|
|
}
|
|
|
|
} else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
|
|
unsigned int remoteid = GET_32BIT(pktin.body);
|
|
unsigned int localid = GET_32BIT(pktin.body+4);
|
|
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);
|
|
}
|
|
|
|
} else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
|
|
pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
|
|
/* Remote side closes a channel. */
|
|
unsigned i = GET_32BIT(pktin.body);
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (c) {
|
|
int closetype;
|
|
closetype =
|
|
(pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
|
|
if (!(c->closes & closetype))
|
|
send_packet(pktin.type, PKT_INT, c->remoteid,
|
|
PKT_END);
|
|
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;
|
|
if (c->closes == 3) {
|
|
del234(ssh_channels, c);
|
|
sfree(c);
|
|
}
|
|
}
|
|
} else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
|
|
/* Data sent down one of our channels. */
|
|
int i = GET_32BIT(pktin.body);
|
|
int len = GET_32BIT(pktin.body + 4);
|
|
unsigned char *p = pktin.body + 8;
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (c) {
|
|
int bufsize;
|
|
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) {
|
|
int l = min(4 - c->u.a.lensofar, 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 = smalloc(c->u.a.totallen);
|
|
memcpy(c->u.a.message, c->u.a.msglen, 4);
|
|
}
|
|
if (c->u.a.lensofar >= 4 && len > 0) {
|
|
int l =
|
|
min(c->u.a.totallen - c->u.a.lensofar,
|
|
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, *sentreply;
|
|
int replylen;
|
|
agent_query(c->u.a.message,
|
|
c->u.a.totallen, &reply,
|
|
&replylen);
|
|
if (reply)
|
|
sentreply = reply;
|
|
else {
|
|
/* Fake SSH_AGENT_FAILURE. */
|
|
sentreply = "\0\0\0\1\5";
|
|
replylen = 5;
|
|
}
|
|
send_packet(SSH1_MSG_CHANNEL_DATA,
|
|
PKT_INT, c->remoteid,
|
|
PKT_INT, replylen,
|
|
PKT_DATA, sentreply, replylen,
|
|
PKT_END);
|
|
if (reply)
|
|
sfree(reply);
|
|
sfree(c->u.a.message);
|
|
c->u.a.lensofar = 0;
|
|
}
|
|
}
|
|
bufsize = 0; /* agent channels never back up */
|
|
break;
|
|
}
|
|
if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
|
|
c->v.v1.throttling = 1;
|
|
ssh1_throttle(+1);
|
|
}
|
|
}
|
|
} else 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 if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
|
|
send_packet(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_state = SSH_STATE_CLOSED;
|
|
crReturnV;
|
|
} else {
|
|
bombout(("Strange packet received: type %d", pktin.type));
|
|
crReturnV;
|
|
}
|
|
} else {
|
|
while (inlen > 0) {
|
|
int len = min(inlen, 512);
|
|
send_packet(SSH1_CMSG_STDIN_DATA,
|
|
PKT_INT, len, PKT_DATA, in, len, PKT_END);
|
|
in += len;
|
|
inlen -= len;
|
|
}
|
|
}
|
|
}
|
|
|
|
crFinishV;
|
|
}
|
|
|
|
/*
|
|
* Utility routine for decoding comma-separated strings in KEXINIT.
|
|
*/
|
|
static int in_commasep_string(char *needle, char *haystack, int haylen)
|
|
{
|
|
int 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 */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* SSH2 key creation method.
|
|
*/
|
|
static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
|
|
char *keyspace)
|
|
{
|
|
SHA_State s;
|
|
/* First 20 bytes. */
|
|
SHA_Init(&s);
|
|
sha_mpint(&s, K);
|
|
SHA_Bytes(&s, H, 20);
|
|
SHA_Bytes(&s, &chr, 1);
|
|
SHA_Bytes(&s, sessid, 20);
|
|
SHA_Final(&s, keyspace);
|
|
/* Next 20 bytes. */
|
|
SHA_Init(&s);
|
|
sha_mpint(&s, K);
|
|
SHA_Bytes(&s, H, 20);
|
|
SHA_Bytes(&s, keyspace, 20);
|
|
SHA_Final(&s, keyspace + 20);
|
|
}
|
|
|
|
/*
|
|
* Handle the SSH2 transport layer.
|
|
*/
|
|
static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
|
|
{
|
|
static int i, j, len, nbits, pbits, warn;
|
|
static char *str;
|
|
static Bignum p, g, e, f, K;
|
|
static int kex_init_value, kex_reply_value;
|
|
static const struct ssh_mac **maclist;
|
|
static int nmacs;
|
|
static const struct ssh2_cipher *cscipher_tobe = NULL;
|
|
static const struct ssh2_cipher *sccipher_tobe = NULL;
|
|
static const struct ssh_mac *csmac_tobe = NULL;
|
|
static const struct ssh_mac *scmac_tobe = NULL;
|
|
static const struct ssh_compress *cscomp_tobe = NULL;
|
|
static const struct ssh_compress *sccomp_tobe = NULL;
|
|
static char *hostkeydata, *sigdata, *keystr, *fingerprint;
|
|
static int hostkeylen, siglen;
|
|
static void *hkey; /* actual host key */
|
|
static unsigned char exchange_hash[20];
|
|
static unsigned char keyspace[40];
|
|
static int n_preferred_ciphers;
|
|
static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
|
|
static const struct ssh_compress *preferred_comp;
|
|
static int first_kex;
|
|
|
|
crBegin;
|
|
random_init();
|
|
first_kex = 1;
|
|
|
|
/*
|
|
* Set up the preferred ciphers. (NULL => warn below here)
|
|
*/
|
|
n_preferred_ciphers = 0;
|
|
for (i = 0; i < CIPHER_MAX; i++) {
|
|
switch (cfg.ssh_cipherlist[i]) {
|
|
case CIPHER_BLOWFISH:
|
|
preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
|
|
n_preferred_ciphers++;
|
|
break;
|
|
case CIPHER_DES:
|
|
preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
|
|
n_preferred_ciphers++;
|
|
break;
|
|
case CIPHER_3DES:
|
|
preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
|
|
n_preferred_ciphers++;
|
|
break;
|
|
case CIPHER_AES:
|
|
preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
|
|
n_preferred_ciphers++;
|
|
break;
|
|
case CIPHER_WARN:
|
|
/* Flag for later. Don't bother if it's the last in
|
|
* the list. */
|
|
if (i < CIPHER_MAX - 1) {
|
|
preferred_ciphers[n_preferred_ciphers] = NULL;
|
|
n_preferred_ciphers++;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set up preferred compression.
|
|
*/
|
|
if (cfg.compression)
|
|
preferred_comp = &ssh_zlib;
|
|
else
|
|
preferred_comp = &ssh_comp_none;
|
|
|
|
/*
|
|
* Be prepared to work around the buggy MAC problem.
|
|
*/
|
|
if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
|
|
maclist = buggymacs, nmacs = lenof(buggymacs);
|
|
else
|
|
maclist = macs, nmacs = lenof(macs);
|
|
|
|
begin_key_exchange:
|
|
/*
|
|
* Construct and send our key exchange packet.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_KEXINIT);
|
|
for (i = 0; i < 16; i++)
|
|
ssh2_pkt_addbyte((unsigned char) random_byte());
|
|
/* List key exchange algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < lenof(kex_algs); i++) {
|
|
ssh2_pkt_addstring_str(kex_algs[i]->name);
|
|
if (i < lenof(kex_algs) - 1)
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
/* List server host key algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < lenof(hostkey_algs); i++) {
|
|
ssh2_pkt_addstring_str(hostkey_algs[i]->name);
|
|
if (i < lenof(hostkey_algs) - 1)
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
/* List client->server encryption algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = preferred_ciphers[i];
|
|
if (!c) continue; /* warning flag */
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
ssh2_pkt_addstring_str(c->list[j]->name);
|
|
if (i < n_preferred_ciphers || j < c->nciphers - 1)
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
}
|
|
/* List server->client encryption algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = preferred_ciphers[i];
|
|
if (!c) continue; /* warning flag */
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
ssh2_pkt_addstring_str(c->list[j]->name);
|
|
if (i < n_preferred_ciphers || j < c->nciphers - 1)
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
}
|
|
/* List client->server MAC algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < nmacs; i++) {
|
|
ssh2_pkt_addstring_str(maclist[i]->name);
|
|
if (i < nmacs - 1)
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
/* List server->client MAC algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < nmacs; i++) {
|
|
ssh2_pkt_addstring_str(maclist[i]->name);
|
|
if (i < nmacs - 1)
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
/* List client->server compression algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < lenof(compressions) + 1; i++) {
|
|
const struct ssh_compress *c =
|
|
i == 0 ? preferred_comp : compressions[i - 1];
|
|
ssh2_pkt_addstring_str(c->name);
|
|
if (i < lenof(compressions))
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
/* List server->client compression algorithms. */
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < lenof(compressions) + 1; i++) {
|
|
const struct ssh_compress *c =
|
|
i == 0 ? preferred_comp : compressions[i - 1];
|
|
ssh2_pkt_addstring_str(c->name);
|
|
if (i < lenof(compressions))
|
|
ssh2_pkt_addstring_str(",");
|
|
}
|
|
/* List client->server languages. Empty list. */
|
|
ssh2_pkt_addstring_start();
|
|
/* List server->client languages. Empty list. */
|
|
ssh2_pkt_addstring_start();
|
|
/* First KEX packet does _not_ follow, because we're not that brave. */
|
|
ssh2_pkt_addbool(FALSE);
|
|
/* Reserved. */
|
|
ssh2_pkt_adduint32(0);
|
|
|
|
exhash = exhashbase;
|
|
sha_string(&exhash, pktout.data + 5, pktout.length - 5);
|
|
|
|
ssh2_pkt_send();
|
|
|
|
if (!ispkt)
|
|
crWaitUntil(ispkt);
|
|
sha_string(&exhash, pktin.data + 5, pktin.length - 5);
|
|
|
|
/*
|
|
* Now examine the other side's KEXINIT to see what we're up
|
|
* to.
|
|
*/
|
|
if (pktin.type != SSH2_MSG_KEXINIT) {
|
|
bombout(("expected key exchange packet from server"));
|
|
crReturn(0);
|
|
}
|
|
kex = NULL;
|
|
hostkey = NULL;
|
|
cscipher_tobe = NULL;
|
|
sccipher_tobe = NULL;
|
|
csmac_tobe = NULL;
|
|
scmac_tobe = NULL;
|
|
cscomp_tobe = NULL;
|
|
sccomp_tobe = NULL;
|
|
pktin.savedpos += 16; /* skip garbage cookie */
|
|
ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
|
|
for (i = 0; i < lenof(kex_algs); i++) {
|
|
if (in_commasep_string(kex_algs[i]->name, str, len)) {
|
|
kex = kex_algs[i];
|
|
break;
|
|
}
|
|
}
|
|
ssh2_pkt_getstring(&str, &len); /* host key algorithms */
|
|
for (i = 0; i < lenof(hostkey_algs); i++) {
|
|
if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
|
|
hostkey = hostkey_algs[i];
|
|
break;
|
|
}
|
|
}
|
|
ssh2_pkt_getstring(&str, &len); /* client->server cipher */
|
|
warn = 0;
|
|
for (i = 0; i < n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = preferred_ciphers[i];
|
|
if (!c) {
|
|
warn = 1;
|
|
} else {
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
if (in_commasep_string(c->list[j]->name, str, len)) {
|
|
cscipher_tobe = c->list[j];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (cscipher_tobe) {
|
|
if (warn)
|
|
askcipher(cscipher_tobe->name, 1);
|
|
break;
|
|
}
|
|
}
|
|
if (!cscipher_tobe) {
|
|
bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
|
|
crReturn(0);
|
|
}
|
|
|
|
ssh2_pkt_getstring(&str, &len); /* server->client cipher */
|
|
warn = 0;
|
|
for (i = 0; i < n_preferred_ciphers; i++) {
|
|
const struct ssh2_ciphers *c = preferred_ciphers[i];
|
|
if (!c) {
|
|
warn = 1;
|
|
} else {
|
|
for (j = 0; j < c->nciphers; j++) {
|
|
if (in_commasep_string(c->list[j]->name, str, len)) {
|
|
sccipher_tobe = c->list[j];
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (sccipher_tobe) {
|
|
if (warn)
|
|
askcipher(sccipher_tobe->name, 2);
|
|
break;
|
|
}
|
|
}
|
|
if (!sccipher_tobe) {
|
|
bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
|
|
crReturn(0);
|
|
}
|
|
|
|
ssh2_pkt_getstring(&str, &len); /* client->server mac */
|
|
for (i = 0; i < nmacs; i++) {
|
|
if (in_commasep_string(maclist[i]->name, str, len)) {
|
|
csmac_tobe = maclist[i];
|
|
break;
|
|
}
|
|
}
|
|
ssh2_pkt_getstring(&str, &len); /* server->client mac */
|
|
for (i = 0; i < nmacs; i++) {
|
|
if (in_commasep_string(maclist[i]->name, str, len)) {
|
|
scmac_tobe = maclist[i];
|
|
break;
|
|
}
|
|
}
|
|
ssh2_pkt_getstring(&str, &len); /* client->server compression */
|
|
for (i = 0; i < lenof(compressions) + 1; i++) {
|
|
const struct ssh_compress *c =
|
|
i == 0 ? preferred_comp : compressions[i - 1];
|
|
if (in_commasep_string(c->name, str, len)) {
|
|
cscomp_tobe = c;
|
|
break;
|
|
}
|
|
}
|
|
ssh2_pkt_getstring(&str, &len); /* server->client compression */
|
|
for (i = 0; i < lenof(compressions) + 1; i++) {
|
|
const struct ssh_compress *c =
|
|
i == 0 ? preferred_comp : compressions[i - 1];
|
|
if (in_commasep_string(c->name, str, len)) {
|
|
sccomp_tobe = c;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 = cscipher_tobe->keylen;
|
|
scbits = sccipher_tobe->keylen;
|
|
nbits = (csbits > scbits ? csbits : scbits);
|
|
}
|
|
/* The keys only have 160-bit entropy, since they're based on
|
|
* a SHA-1 hash. So cap the key size at 160 bits. */
|
|
if (nbits > 160)
|
|
nbits = 160;
|
|
|
|
/*
|
|
* If we're doing Diffie-Hellman group exchange, start by
|
|
* requesting a group.
|
|
*/
|
|
if (kex == &ssh_diffiehellman_gex) {
|
|
logevent("Doing Diffie-Hellman group exchange");
|
|
/*
|
|
* Work out how big a DH group we will need to allow that
|
|
* much data.
|
|
*/
|
|
pbits = 512 << ((nbits - 1) / 64);
|
|
ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
|
|
ssh2_pkt_adduint32(pbits);
|
|
ssh2_pkt_send();
|
|
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
|
|
bombout(("expected key exchange group packet from server"));
|
|
crReturn(0);
|
|
}
|
|
p = ssh2_pkt_getmp();
|
|
g = ssh2_pkt_getmp();
|
|
dh_setup_group(p, g);
|
|
kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
|
|
kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
|
|
} else {
|
|
dh_setup_group1();
|
|
kex_init_value = SSH2_MSG_KEXDH_INIT;
|
|
kex_reply_value = SSH2_MSG_KEXDH_REPLY;
|
|
}
|
|
|
|
logevent("Doing Diffie-Hellman key exchange");
|
|
/*
|
|
* Now generate and send e for Diffie-Hellman.
|
|
*/
|
|
e = dh_create_e(nbits * 2);
|
|
ssh2_pkt_init(kex_init_value);
|
|
ssh2_pkt_addmp(e);
|
|
ssh2_pkt_send();
|
|
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type != kex_reply_value) {
|
|
bombout(("expected key exchange reply packet from server"));
|
|
crReturn(0);
|
|
}
|
|
ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
|
|
f = ssh2_pkt_getmp();
|
|
ssh2_pkt_getstring(&sigdata, &siglen);
|
|
|
|
K = dh_find_K(f);
|
|
|
|
sha_string(&exhash, hostkeydata, hostkeylen);
|
|
if (kex == &ssh_diffiehellman_gex) {
|
|
sha_uint32(&exhash, pbits);
|
|
sha_mpint(&exhash, p);
|
|
sha_mpint(&exhash, g);
|
|
}
|
|
sha_mpint(&exhash, e);
|
|
sha_mpint(&exhash, f);
|
|
sha_mpint(&exhash, K);
|
|
SHA_Final(&exhash, exchange_hash);
|
|
|
|
dh_cleanup();
|
|
|
|
#if 0
|
|
debug(("Exchange hash is:\n"));
|
|
dmemdump(exchange_hash, 20);
|
|
#endif
|
|
|
|
hkey = hostkey->newkey(hostkeydata, hostkeylen);
|
|
if (!hkey ||
|
|
!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
|
|
bombout(("Server's host key did not match the signature supplied"));
|
|
crReturn(0);
|
|
}
|
|
|
|
/*
|
|
* Authenticate remote host: verify host key. (We've already
|
|
* checked the signature of the exchange hash.)
|
|
*/
|
|
keystr = hostkey->fmtkey(hkey);
|
|
fingerprint = hostkey->fingerprint(hkey);
|
|
verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
|
|
keystr, fingerprint);
|
|
if (first_kex) { /* don't bother logging this in rekeys */
|
|
logevent("Host key fingerprint is:");
|
|
logevent(fingerprint);
|
|
}
|
|
sfree(fingerprint);
|
|
sfree(keystr);
|
|
hostkey->freekey(hkey);
|
|
|
|
/*
|
|
* Send SSH2_MSG_NEWKEYS.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_NEWKEYS);
|
|
ssh2_pkt_send();
|
|
|
|
/*
|
|
* Expect SSH2_MSG_NEWKEYS from server.
|
|
*/
|
|
crWaitUntil(ispkt);
|
|
if (pktin.type != SSH2_MSG_NEWKEYS) {
|
|
bombout(("expected new-keys packet from server"));
|
|
crReturn(0);
|
|
}
|
|
|
|
/*
|
|
* Create and initialise session keys.
|
|
*/
|
|
cscipher = cscipher_tobe;
|
|
sccipher = sccipher_tobe;
|
|
csmac = csmac_tobe;
|
|
scmac = scmac_tobe;
|
|
cscomp = cscomp_tobe;
|
|
sccomp = sccomp_tobe;
|
|
cscomp->compress_init();
|
|
sccomp->decompress_init();
|
|
/*
|
|
* Set IVs after keys. Here we use the exchange hash from the
|
|
* _first_ key exchange.
|
|
*/
|
|
if (first_kex)
|
|
memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
|
|
ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
|
|
cscipher->setcskey(keyspace);
|
|
ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
|
|
sccipher->setsckey(keyspace);
|
|
ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
|
|
cscipher->setcsiv(keyspace);
|
|
ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
|
|
sccipher->setsciv(keyspace);
|
|
ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
|
|
csmac->setcskey(keyspace);
|
|
ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
|
|
scmac->setsckey(keyspace);
|
|
|
|
/*
|
|
* 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 (!first_kex) {
|
|
crReturn(0);
|
|
}
|
|
first_kex = 0;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
|
|
crReturn(1);
|
|
}
|
|
logevent("Server initiated key re-exchange");
|
|
goto begin_key_exchange;
|
|
|
|
crFinish(1);
|
|
}
|
|
|
|
/*
|
|
* Add data to an SSH2 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 SSH2 channel.
|
|
*/
|
|
static int ssh2_try_send(struct ssh_channel *c)
|
|
{
|
|
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;
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(data, len);
|
|
ssh2_pkt_send();
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* Potentially enlarge the window on an SSH2 channel.
|
|
*/
|
|
static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
|
|
{
|
|
if (newwin > c->v.v2.locwindow) {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
|
|
ssh2_pkt_send();
|
|
c->v.v2.locwindow = newwin;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle the SSH2 userauth and connection layers.
|
|
*/
|
|
static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
|
|
{
|
|
static enum {
|
|
AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
|
|
AUTH_PASSWORD,
|
|
AUTH_KEYBOARD_INTERACTIVE
|
|
} method;
|
|
static enum {
|
|
AUTH_TYPE_NONE,
|
|
AUTH_TYPE_PUBLICKEY,
|
|
AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
|
|
AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
|
|
AUTH_TYPE_PASSWORD,
|
|
AUTH_TYPE_KEYBOARD_INTERACTIVE,
|
|
AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
|
|
} type;
|
|
static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
|
|
static int tried_pubkey_config, tried_agent, tried_keyb_inter;
|
|
static int kbd_inter_running;
|
|
static int we_are_in;
|
|
static int num_prompts, echo;
|
|
static char username[100];
|
|
static char pwprompt[200];
|
|
static char password[100];
|
|
|
|
crBegin;
|
|
|
|
/*
|
|
* Request userauth protocol, and await a response to it.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
|
|
ssh2_pkt_addstring("ssh-userauth");
|
|
ssh2_pkt_send();
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
|
|
bombout(("Server refused user authentication protocol"));
|
|
crReturnV;
|
|
}
|
|
|
|
/*
|
|
* We repeat this whole loop, including the username prompt,
|
|
* until we manage a successful authentication. If the user
|
|
* types the wrong _password_, they are sent back to the
|
|
* beginning to try another username. (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!
|
|
*/
|
|
do {
|
|
static int pos;
|
|
static char c;
|
|
|
|
/*
|
|
* Get a username.
|
|
*/
|
|
pos = 0;
|
|
if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
|
|
if (ssh_get_line) {
|
|
if (!ssh_get_line("login as: ",
|
|
username, sizeof(username), FALSE)) {
|
|
/*
|
|
* get_line failed to get a username.
|
|
* Terminate.
|
|
*/
|
|
logevent("No username provided. Abandoning session.");
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturnV;
|
|
}
|
|
} else {
|
|
c_write_str("login as: ");
|
|
ssh_send_ok = 1;
|
|
while (pos >= 0) {
|
|
crWaitUntilV(!ispkt);
|
|
while (inlen--)
|
|
switch (c = *in++) {
|
|
case 10:
|
|
case 13:
|
|
username[pos] = 0;
|
|
pos = -1;
|
|
break;
|
|
case 8:
|
|
case 127:
|
|
if (pos > 0) {
|
|
c_write_str("\b \b");
|
|
pos--;
|
|
}
|
|
break;
|
|
case 21:
|
|
case 27:
|
|
while (pos > 0) {
|
|
c_write_str("\b \b");
|
|
pos--;
|
|
}
|
|
break;
|
|
case 3:
|
|
case 4:
|
|
random_save_seed();
|
|
exit(0);
|
|
break;
|
|
default:
|
|
if (((c >= ' ' && c <= '~') ||
|
|
((unsigned char) c >= 160))
|
|
&& pos < sizeof(username)-1) {
|
|
username[pos++] = c;
|
|
c_write(&c, 1);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
c_write_str("\r\n");
|
|
username[strcspn(username, "\n\r")] = '\0';
|
|
} else {
|
|
char stuff[200];
|
|
strncpy(username, cfg.username, 99);
|
|
username[99] = '\0';
|
|
if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
|
|
sprintf(stuff, "Using username \"%s\".\r\n", username);
|
|
c_write_str(stuff);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("none"); /* method */
|
|
ssh2_pkt_send();
|
|
type = AUTH_TYPE_NONE;
|
|
gotit = FALSE;
|
|
we_are_in = FALSE;
|
|
|
|
tried_pubkey_config = FALSE;
|
|
tried_agent = FALSE;
|
|
tried_keyb_inter = FALSE;
|
|
kbd_inter_running = FALSE;
|
|
|
|
while (1) {
|
|
/*
|
|
* Wait for the result of the last authentication request.
|
|
*/
|
|
if (!gotit)
|
|
crWaitUntilV(ispkt);
|
|
while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
|
|
char *banner;
|
|
int size;
|
|
/*
|
|
* 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 (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
|
|
ssh2_pkt_getstring(&banner, &size);
|
|
if (banner)
|
|
c_write_untrusted(banner, size);
|
|
}
|
|
crWaitUntilV(ispkt);
|
|
}
|
|
if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
|
|
logevent("Access granted");
|
|
we_are_in = TRUE;
|
|
break;
|
|
}
|
|
|
|
if (kbd_inter_running &&
|
|
pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
|
|
/*
|
|
* This is a further prompt in keyboard-interactive
|
|
* authentication. Do nothing.
|
|
*/
|
|
} else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
|
|
bombout(("Strange packet received during authentication: type %d",
|
|
pktin.type));
|
|
crReturnV;
|
|
}
|
|
|
|
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;
|
|
ssh2_pkt_getstring(&methods, &methlen);
|
|
kbd_inter_running = FALSE;
|
|
if (!ssh2_pkt_getbool()) {
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (type == AUTH_TYPE_NONE) {
|
|
/* do nothing */
|
|
} else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
|
|
type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
|
|
if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
|
|
c_write_str("Server refused our key\r\n");
|
|
logevent("Server refused public key");
|
|
} else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
|
|
/* server declined keyboard-interactive; ignore */
|
|
} else {
|
|
c_write_str("Access denied\r\n");
|
|
logevent("Access denied");
|
|
if (type == AUTH_TYPE_PASSWORD) {
|
|
we_are_in = FALSE;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
c_write_str("Further authentication required\r\n");
|
|
logevent("Further authentication required");
|
|
}
|
|
|
|
can_pubkey =
|
|
in_commasep_string("publickey", methods, methlen);
|
|
can_passwd =
|
|
in_commasep_string("password", methods, methlen);
|
|
can_keyb_inter = cfg.try_ki_auth &&
|
|
in_commasep_string("keyboard-interactive", methods, methlen);
|
|
}
|
|
|
|
method = 0;
|
|
|
|
if (!method && can_pubkey && agent_exists() && !tried_agent) {
|
|
/*
|
|
* Attempt public-key authentication using Pageant.
|
|
*/
|
|
static unsigned char request[5], *response, *p;
|
|
static int responselen;
|
|
static int i, nkeys;
|
|
static int authed = FALSE;
|
|
void *r;
|
|
|
|
tried_agent = TRUE;
|
|
|
|
logevent("Pageant is running. Requesting keys.");
|
|
|
|
/* Request the keys held by the agent. */
|
|
PUT_32BIT(request, 1);
|
|
request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
|
|
agent_query(request, 5, &r, &responselen);
|
|
response = (unsigned char *) r;
|
|
if (response && responselen >= 5 &&
|
|
response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
|
|
p = response + 5;
|
|
nkeys = GET_32BIT(p);
|
|
p += 4;
|
|
{
|
|
char buf[64];
|
|
sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
|
|
logevent(buf);
|
|
}
|
|
for (i = 0; i < nkeys; i++) {
|
|
static char *pkblob, *alg, *commentp;
|
|
static int pklen, alglen, commentlen;
|
|
static int siglen, retlen, len;
|
|
static char *q, *agentreq, *ret;
|
|
void *vret;
|
|
|
|
{
|
|
char buf[64];
|
|
sprintf(buf, "Trying Pageant key #%d", i);
|
|
logevent(buf);
|
|
}
|
|
pklen = GET_32BIT(p);
|
|
p += 4;
|
|
pkblob = p;
|
|
p += pklen;
|
|
alglen = GET_32BIT(pkblob);
|
|
alg = pkblob + 4;
|
|
commentlen = GET_32BIT(p);
|
|
p += 4;
|
|
commentp = p;
|
|
p += commentlen;
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("publickey"); /* method */
|
|
ssh2_pkt_addbool(FALSE); /* no signature included */
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(alg, alglen);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(pkblob, pklen);
|
|
ssh2_pkt_send();
|
|
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
|
|
logevent("Key refused");
|
|
continue;
|
|
}
|
|
|
|
if (flags & FLAG_VERBOSE) {
|
|
c_write_str
|
|
("Authenticating with public key \"");
|
|
c_write(commentp, commentlen);
|
|
c_write_str("\" from agent\r\n");
|
|
}
|
|
|
|
/*
|
|
* Server is willing to accept the key.
|
|
* Construct a SIGN_REQUEST.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("publickey"); /* method */
|
|
ssh2_pkt_addbool(TRUE);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(alg, alglen);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(pkblob, pklen);
|
|
|
|
siglen = pktout.length - 5 + 4 + 20;
|
|
len = 1; /* message type */
|
|
len += 4 + pklen; /* key blob */
|
|
len += 4 + siglen; /* data to sign */
|
|
len += 4; /* flags */
|
|
agentreq = smalloc(4 + len);
|
|
PUT_32BIT(agentreq, len);
|
|
q = agentreq + 4;
|
|
*q++ = SSH2_AGENTC_SIGN_REQUEST;
|
|
PUT_32BIT(q, pklen);
|
|
q += 4;
|
|
memcpy(q, pkblob, pklen);
|
|
q += pklen;
|
|
PUT_32BIT(q, siglen);
|
|
q += 4;
|
|
/* Now the data to be signed... */
|
|
PUT_32BIT(q, 20);
|
|
q += 4;
|
|
memcpy(q, ssh2_session_id, 20);
|
|
q += 20;
|
|
memcpy(q, pktout.data + 5, pktout.length - 5);
|
|
q += pktout.length - 5;
|
|
/* And finally the (zero) flags word. */
|
|
PUT_32BIT(q, 0);
|
|
agent_query(agentreq, len + 4, &vret, &retlen);
|
|
ret = vret;
|
|
sfree(agentreq);
|
|
if (ret) {
|
|
if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
|
|
logevent("Sending Pageant's response");
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(ret + 9,
|
|
GET_32BIT(ret +
|
|
5));
|
|
ssh2_pkt_send();
|
|
authed = TRUE;
|
|
break;
|
|
} else {
|
|
logevent
|
|
("Pageant failed to answer challenge");
|
|
sfree(ret);
|
|
}
|
|
}
|
|
}
|
|
if (authed)
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (!method && can_pubkey && *cfg.keyfile
|
|
&& !tried_pubkey_config) {
|
|
unsigned char *pub_blob;
|
|
char *algorithm, *comment;
|
|
int pub_blob_len;
|
|
|
|
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.
|
|
*/
|
|
pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
|
|
&pub_blob_len);
|
|
if (pub_blob) {
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("publickey"); /* method */
|
|
ssh2_pkt_addbool(FALSE); /* no signature included */
|
|
ssh2_pkt_addstring(algorithm);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
|
|
ssh2_pkt_send();
|
|
logevent("Offered public key"); /* FIXME */
|
|
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
|
|
gotit = TRUE;
|
|
type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
|
|
continue; /* key refused; give up on it */
|
|
}
|
|
|
|
logevent("Offer of public key accepted");
|
|
/*
|
|
* Actually attempt a serious authentication using
|
|
* the key.
|
|
*/
|
|
if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
|
|
sprintf(pwprompt,
|
|
"Passphrase for key \"%.100s\": ",
|
|
comment);
|
|
need_pw = TRUE;
|
|
} else {
|
|
need_pw = FALSE;
|
|
}
|
|
c_write_str("Authenticating with public key \"");
|
|
c_write_str(comment);
|
|
c_write_str("\"\r\n");
|
|
method = AUTH_PUBLICKEY_FILE;
|
|
}
|
|
}
|
|
|
|
if (!method && can_keyb_inter && !tried_keyb_inter) {
|
|
method = AUTH_KEYBOARD_INTERACTIVE;
|
|
type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
|
|
tried_keyb_inter = TRUE;
|
|
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("keyboard-interactive"); /* method */
|
|
ssh2_pkt_addstring(""); /* lang */
|
|
ssh2_pkt_addstring("");
|
|
ssh2_pkt_send();
|
|
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
|
|
if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
|
|
gotit = TRUE;
|
|
logevent("Keyboard-interactive authentication refused");
|
|
type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
|
|
continue;
|
|
}
|
|
|
|
kbd_inter_running = TRUE;
|
|
}
|
|
|
|
if (kbd_inter_running) {
|
|
method = AUTH_KEYBOARD_INTERACTIVE;
|
|
type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
|
|
tried_keyb_inter = TRUE;
|
|
|
|
/* We've got packet with that "interactive" info
|
|
dump banners, and set its prompt as ours */
|
|
{
|
|
char *name, *inst, *lang, *prompt;
|
|
int name_len, inst_len, lang_len, prompt_len;
|
|
ssh2_pkt_getstring(&name, &name_len);
|
|
ssh2_pkt_getstring(&inst, &inst_len);
|
|
ssh2_pkt_getstring(&lang, &lang_len);
|
|
if (name_len > 0)
|
|
c_write_untrusted(name, name_len);
|
|
if (inst_len > 0)
|
|
c_write_untrusted(inst, inst_len);
|
|
num_prompts = ssh2_pkt_getuint32();
|
|
|
|
ssh2_pkt_getstring(&prompt, &prompt_len);
|
|
strncpy(pwprompt, prompt, sizeof(pwprompt));
|
|
pwprompt[prompt_len < sizeof(pwprompt) ?
|
|
prompt_len : sizeof(pwprompt)-1] = '\0';
|
|
need_pw = TRUE;
|
|
|
|
echo = ssh2_pkt_getbool();
|
|
}
|
|
}
|
|
|
|
if (!method && can_passwd) {
|
|
method = AUTH_PASSWORD;
|
|
sprintf(pwprompt, "%.90s@%.90s's password: ", username,
|
|
savedhost);
|
|
need_pw = TRUE;
|
|
}
|
|
|
|
if (need_pw) {
|
|
if (ssh_get_line) {
|
|
if (!ssh_get_line(pwprompt, password,
|
|
sizeof(password), TRUE)) {
|
|
/*
|
|
* get_line failed to get a password (for
|
|
* example because one was supplied on the
|
|
* command line which has already failed to
|
|
* work). Terminate.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_DISCONNECT);
|
|
ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
|
|
ssh2_pkt_addstring
|
|
("No more passwords available to try");
|
|
ssh2_pkt_addstring("en"); /* language tag */
|
|
ssh2_pkt_send();
|
|
connection_fatal("Unable to authenticate");
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturnV;
|
|
}
|
|
} else {
|
|
static int pos = 0;
|
|
static char c;
|
|
|
|
c_write_untrusted(pwprompt, strlen(pwprompt));
|
|
ssh_send_ok = 1;
|
|
|
|
pos = 0;
|
|
while (pos >= 0) {
|
|
crWaitUntilV(!ispkt);
|
|
while (inlen--)
|
|
switch (c = *in++) {
|
|
case 10:
|
|
case 13:
|
|
password[pos] = 0;
|
|
pos = -1;
|
|
break;
|
|
case 8:
|
|
case 127:
|
|
if (pos > 0)
|
|
pos--;
|
|
break;
|
|
case 21:
|
|
case 27:
|
|
pos = 0;
|
|
break;
|
|
case 3:
|
|
case 4:
|
|
random_save_seed();
|
|
exit(0);
|
|
break;
|
|
default:
|
|
if (pos < sizeof(password)-1)
|
|
password[pos++] = c;
|
|
break;
|
|
}
|
|
}
|
|
c_write_str("\r\n");
|
|
}
|
|
}
|
|
|
|
if (method == AUTH_PUBLICKEY_FILE) {
|
|
/*
|
|
* We have our passphrase. Now try the actual authentication.
|
|
*/
|
|
struct ssh2_userkey *key;
|
|
|
|
key = ssh2_load_userkey(cfg.keyfile, password);
|
|
if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
|
|
if (key == SSH2_WRONG_PASSPHRASE) {
|
|
c_write_str("Wrong passphrase\r\n");
|
|
tried_pubkey_config = FALSE;
|
|
} else {
|
|
c_write_str("Unable to load private key\r\n");
|
|
tried_pubkey_config = TRUE;
|
|
}
|
|
/* Send a spurious AUTH_NONE to return to the top. */
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("none"); /* method */
|
|
ssh2_pkt_send();
|
|
type = AUTH_TYPE_NONE;
|
|
} else {
|
|
unsigned char *blob, *sigdata;
|
|
int blob_len, sigdata_len;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("publickey"); /* method */
|
|
ssh2_pkt_addbool(TRUE);
|
|
ssh2_pkt_addstring(key->alg->name);
|
|
blob = key->alg->public_blob(key->data, &blob_len);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(blob, blob_len);
|
|
sfree(blob);
|
|
|
|
/*
|
|
* The data to be signed is:
|
|
*
|
|
* string session-id
|
|
*
|
|
* followed by everything so far placed in the
|
|
* outgoing packet.
|
|
*/
|
|
sigdata_len = pktout.length - 5 + 4 + 20;
|
|
sigdata = smalloc(sigdata_len);
|
|
PUT_32BIT(sigdata, 20);
|
|
memcpy(sigdata + 4, ssh2_session_id, 20);
|
|
memcpy(sigdata + 24, pktout.data + 5,
|
|
pktout.length - 5);
|
|
blob =
|
|
key->alg->sign(key->data, sigdata, sigdata_len,
|
|
&blob_len);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data(blob, blob_len);
|
|
sfree(blob);
|
|
sfree(sigdata);
|
|
|
|
ssh2_pkt_send();
|
|
type = AUTH_TYPE_PUBLICKEY;
|
|
}
|
|
} else if (method == AUTH_PASSWORD) {
|
|
/*
|
|
* We send the password packet lumped tightly together with
|
|
* an SSH_MSG_IGNORE packet. The IGNORE packet contains a
|
|
* string long enough to make the total length of the two
|
|
* packets constant. This should ensure that a passive
|
|
* listener doing traffic analyis can't work out the length
|
|
* of the password.
|
|
*
|
|
* For this to work, we need an assumption about the
|
|
* maximum length of the password packet. I think 256 is
|
|
* pretty conservative. Anyone using a password longer than
|
|
* that probably doesn't have much to worry about from
|
|
* people who find out how long their password is!
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
|
|
ssh2_pkt_addstring(username);
|
|
ssh2_pkt_addstring("ssh-connection"); /* service requested */
|
|
ssh2_pkt_addstring("password");
|
|
ssh2_pkt_addbool(FALSE);
|
|
ssh2_pkt_addstring(password);
|
|
ssh2_pkt_defer();
|
|
/*
|
|
* We'll include a string that's an exact multiple of the
|
|
* cipher block size. If the cipher is NULL for some
|
|
* reason, we don't do this trick at all because we gain
|
|
* nothing by it.
|
|
*/
|
|
if (cscipher) {
|
|
int stringlen, i;
|
|
|
|
stringlen = (256 - deferred_len);
|
|
stringlen += cscipher->blksize - 1;
|
|
stringlen -= (stringlen % cscipher->blksize);
|
|
if (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 -= cscomp->disable_compression();
|
|
}
|
|
ssh2_pkt_init(SSH2_MSG_IGNORE);
|
|
ssh2_pkt_addstring_start();
|
|
for (i = 0; i < stringlen; i++) {
|
|
char c = (char) random_byte();
|
|
ssh2_pkt_addstring_data(&c, 1);
|
|
}
|
|
ssh2_pkt_defer();
|
|
}
|
|
ssh_pkt_defersend();
|
|
logevent("Sent password");
|
|
type = AUTH_TYPE_PASSWORD;
|
|
} else if (method == AUTH_KEYBOARD_INTERACTIVE) {
|
|
ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
|
|
ssh2_pkt_adduint32(num_prompts);
|
|
ssh2_pkt_addstring(password);
|
|
memset(password, 0, sizeof(password));
|
|
ssh2_pkt_send();
|
|
type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
|
|
} else {
|
|
c_write_str
|
|
("No supported authentication methods left to try!\r\n");
|
|
logevent
|
|
("No supported authentications offered. Disconnecting");
|
|
ssh2_pkt_init(SSH2_MSG_DISCONNECT);
|
|
ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
|
|
ssh2_pkt_addstring
|
|
("No supported authentication methods available");
|
|
ssh2_pkt_addstring("en"); /* language tag */
|
|
ssh2_pkt_send();
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturnV;
|
|
}
|
|
}
|
|
} while (!we_are_in);
|
|
|
|
/*
|
|
* Now we're authenticated for the connection protocol. The
|
|
* connection protocol will automatically have started at this
|
|
* point; there's no need to send SERVICE_REQUEST.
|
|
*/
|
|
|
|
/*
|
|
* So now create a channel with a session in it.
|
|
*/
|
|
ssh_channels = newtree234(ssh_channelcmp);
|
|
mainchan = smalloc(sizeof(struct ssh_channel));
|
|
mainchan->localid = alloc_channel_id();
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
|
|
ssh2_pkt_addstring("session");
|
|
ssh2_pkt_adduint32(mainchan->localid);
|
|
mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
|
|
ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
|
|
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
|
|
ssh2_pkt_send();
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
|
|
bombout(("Server refused to open a session"));
|
|
crReturnV;
|
|
/* FIXME: error data comes back in FAILURE packet */
|
|
}
|
|
if (ssh2_pkt_getuint32() != mainchan->localid) {
|
|
bombout(("Server's channel confirmation cited wrong channel"));
|
|
crReturnV;
|
|
}
|
|
mainchan->remoteid = ssh2_pkt_getuint32();
|
|
mainchan->type = CHAN_MAINSESSION;
|
|
mainchan->closes = 0;
|
|
mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
|
|
mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
|
|
bufchain_init(&mainchan->v.v2.outbuffer);
|
|
add234(ssh_channels, mainchan);
|
|
logevent("Opened channel for session");
|
|
|
|
/*
|
|
* Potentially enable X11 forwarding.
|
|
*/
|
|
if (cfg.x11_forward) {
|
|
char proto[20], data[64];
|
|
logevent("Requesting X11 forwarding");
|
|
x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(mainchan->remoteid);
|
|
ssh2_pkt_addstring("x11-req");
|
|
ssh2_pkt_addbool(1); /* want reply */
|
|
ssh2_pkt_addbool(0); /* many connections */
|
|
ssh2_pkt_addstring(proto);
|
|
ssh2_pkt_addstring(data);
|
|
ssh2_pkt_adduint32(0); /* screen number */
|
|
ssh2_pkt_send();
|
|
|
|
do {
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
c->v.v2.remwindow += ssh2_pkt_getuint32();
|
|
}
|
|
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
|
|
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));
|
|
crReturnV;
|
|
}
|
|
logevent("X11 forwarding refused");
|
|
} else {
|
|
logevent("X11 forwarding enabled");
|
|
ssh_X11_fwd_enabled = TRUE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Enable port forwardings.
|
|
*/
|
|
{
|
|
static char *e; /* preserve across crReturn */
|
|
char type;
|
|
int n;
|
|
int sport,dport;
|
|
char sports[256], dports[256], host[256];
|
|
char buf[1024];
|
|
|
|
ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
|
|
/* Add port forwardings. */
|
|
e = cfg.portfwd;
|
|
while (*e) {
|
|
type = *e++;
|
|
n = 0;
|
|
while (*e && *e != '\t')
|
|
sports[n++] = *e++;
|
|
sports[n] = 0;
|
|
if (*e == '\t')
|
|
e++;
|
|
n = 0;
|
|
while (*e && *e != ':')
|
|
host[n++] = *e++;
|
|
host[n] = 0;
|
|
if (*e == ':')
|
|
e++;
|
|
n = 0;
|
|
while (*e)
|
|
dports[n++] = *e++;
|
|
dports[n] = 0;
|
|
e++;
|
|
dport = atoi(dports);
|
|
sport = atoi(sports);
|
|
if (sport && dport) {
|
|
if (type == 'L') {
|
|
pfd_addforward(host, dport, sport);
|
|
sprintf(buf, "Local port %d forwarding to %s:%d",
|
|
sport, host, dport);
|
|
logevent(buf);
|
|
} else {
|
|
struct ssh_rportfwd *pf;
|
|
pf = smalloc(sizeof(*pf));
|
|
strcpy(pf->dhost, host);
|
|
pf->dport = dport;
|
|
pf->sport = sport;
|
|
if (add234(ssh_rportfwds, pf) != pf) {
|
|
sprintf(buf,
|
|
"Duplicate remote port forwarding to %s:%d",
|
|
host, dport);
|
|
logevent(buf);
|
|
sfree(pf);
|
|
} else {
|
|
sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
|
|
sport, host, dport);
|
|
logevent(buf);
|
|
ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
|
|
ssh2_pkt_addstring("tcpip-forward");
|
|
ssh2_pkt_addbool(1);/* want reply */
|
|
ssh2_pkt_addstring("127.0.0.1");
|
|
ssh2_pkt_adduint32(sport);
|
|
ssh2_pkt_send();
|
|
|
|
do {
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue;/* nonexistent channel */
|
|
c->v.v2.remwindow += ssh2_pkt_getuint32();
|
|
}
|
|
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
|
|
if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
|
|
if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
|
|
bombout(("Unexpected response to port "
|
|
"forwarding request: packet type %d",
|
|
pktin.type));
|
|
crReturnV;
|
|
}
|
|
logevent("Server refused this port forwarding");
|
|
} else {
|
|
logevent("Remote port forwarding enabled");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Potentially enable agent forwarding.
|
|
*/
|
|
if (cfg.agentfwd && agent_exists()) {
|
|
logevent("Requesting OpenSSH-style agent forwarding");
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(mainchan->remoteid);
|
|
ssh2_pkt_addstring("auth-agent-req@openssh.com");
|
|
ssh2_pkt_addbool(1); /* want reply */
|
|
ssh2_pkt_send();
|
|
|
|
do {
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
c->v.v2.remwindow += ssh2_pkt_getuint32();
|
|
}
|
|
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
|
|
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));
|
|
crReturnV;
|
|
}
|
|
logevent("Agent forwarding refused");
|
|
} else {
|
|
logevent("Agent forwarding enabled");
|
|
ssh_agentfwd_enabled = TRUE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now allocate a pty for the session.
|
|
*/
|
|
if (!cfg.nopty) {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
|
|
ssh2_pkt_addstring("pty-req");
|
|
ssh2_pkt_addbool(1); /* want reply */
|
|
ssh2_pkt_addstring(cfg.termtype);
|
|
ssh2_pkt_adduint32(cols);
|
|
ssh2_pkt_adduint32(rows);
|
|
ssh2_pkt_adduint32(0); /* pixel width */
|
|
ssh2_pkt_adduint32(0); /* pixel height */
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
|
|
ssh2_pkt_send();
|
|
ssh_state = SSH_STATE_INTERMED;
|
|
|
|
do {
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
c->v.v2.remwindow += ssh2_pkt_getuint32();
|
|
}
|
|
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
|
|
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));
|
|
crReturnV;
|
|
}
|
|
c_write_str("Server refused to allocate pty\r\n");
|
|
ssh_editing = ssh_echoing = 1;
|
|
} else {
|
|
logevent("Allocated pty");
|
|
}
|
|
} else {
|
|
ssh_editing = ssh_echoing = 1;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
while (1) {
|
|
int subsys;
|
|
char *cmd;
|
|
|
|
if (ssh_fallback_cmd) {
|
|
subsys = cfg.ssh_subsys2;
|
|
cmd = cfg.remote_cmd_ptr2;
|
|
} else {
|
|
subsys = cfg.ssh_subsys;
|
|
cmd = cfg.remote_cmd_ptr;
|
|
}
|
|
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
|
|
if (subsys) {
|
|
ssh2_pkt_addstring("subsystem");
|
|
ssh2_pkt_addbool(1); /* want reply */
|
|
ssh2_pkt_addstring(cmd);
|
|
} else if (*cmd) {
|
|
ssh2_pkt_addstring("exec");
|
|
ssh2_pkt_addbool(1); /* want reply */
|
|
ssh2_pkt_addstring(cmd);
|
|
} else {
|
|
ssh2_pkt_addstring("shell");
|
|
ssh2_pkt_addbool(1); /* want reply */
|
|
}
|
|
ssh2_pkt_send();
|
|
do {
|
|
crWaitUntilV(ispkt);
|
|
if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
c->v.v2.remwindow += ssh2_pkt_getuint32();
|
|
}
|
|
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
|
|
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));
|
|
crReturnV;
|
|
}
|
|
/*
|
|
* 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 && cfg.remote_cmd_ptr2 != NULL) {
|
|
logevent("Primary command failed; attempting fallback");
|
|
ssh_fallback_cmd = TRUE;
|
|
continue;
|
|
}
|
|
bombout(("Server refused to start a shell/command"));
|
|
crReturnV;
|
|
} else {
|
|
logevent("Started a shell/command");
|
|
}
|
|
break;
|
|
}
|
|
|
|
ssh_state = SSH_STATE_SESSION;
|
|
if (size_needed)
|
|
ssh_size();
|
|
if (eof_needed)
|
|
ssh_special(TS_EOF);
|
|
|
|
/*
|
|
* Transfer data!
|
|
*/
|
|
ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
|
|
ssh_send_ok = 1;
|
|
while (1) {
|
|
static int try_send;
|
|
crReturnV;
|
|
try_send = FALSE;
|
|
if (ispkt) {
|
|
if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
|
|
pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
|
|
char *data;
|
|
int length;
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
|
|
ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
|
|
continue; /* extended but not stderr */
|
|
ssh2_pkt_getstring(&data, &length);
|
|
if (data) {
|
|
int bufsize;
|
|
c->v.v2.locwindow -= length;
|
|
switch (c->type) {
|
|
case CHAN_MAINSESSION:
|
|
bufsize =
|
|
from_backend(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) {
|
|
int l = min(4 - c->u.a.lensofar, 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 = smalloc(c->u.a.totallen);
|
|
memcpy(c->u.a.message, c->u.a.msglen, 4);
|
|
}
|
|
if (c->u.a.lensofar >= 4 && length > 0) {
|
|
int l =
|
|
min(c->u.a.totallen - c->u.a.lensofar,
|
|
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, *sentreply;
|
|
int replylen;
|
|
agent_query(c->u.a.message,
|
|
c->u.a.totallen, &reply,
|
|
&replylen);
|
|
if (reply)
|
|
sentreply = reply;
|
|
else {
|
|
/* Fake SSH_AGENT_FAILURE. */
|
|
sentreply = "\0\0\0\1\5";
|
|
replylen = 5;
|
|
}
|
|
ssh2_add_channel_data(c, sentreply,
|
|
replylen);
|
|
try_send = TRUE;
|
|
if (reply)
|
|
sfree(reply);
|
|
sfree(c->u.a.message);
|
|
c->u.a.lensofar = 0;
|
|
}
|
|
}
|
|
bufsize = 0;
|
|
break;
|
|
}
|
|
/*
|
|
* If we are not buffering too much data,
|
|
* enlarge the window again at the remote side.
|
|
*/
|
|
if (bufsize < OUR_V2_WINSIZE)
|
|
ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
|
|
}
|
|
} else if (pktin.type == SSH2_MSG_DISCONNECT) {
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
logevent("Received disconnect message");
|
|
crReturnV;
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
|
|
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);
|
|
}
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
/* Do pre-close processing on the channel. */
|
|
switch (c->type) {
|
|
case CHAN_MAINSESSION:
|
|
break; /* nothing to see here, move along */
|
|
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) {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_send();
|
|
}
|
|
del234(ssh_channels, c);
|
|
bufchain_clear(&c->v.v2.outbuffer);
|
|
sfree(c);
|
|
|
|
/*
|
|
* See if that was the last channel left open.
|
|
*/
|
|
if (count234(ssh_channels) == 0) {
|
|
logevent("All channels closed. Disconnecting");
|
|
ssh2_pkt_init(SSH2_MSG_DISCONNECT);
|
|
ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
|
|
ssh2_pkt_addstring("All open channels closed");
|
|
ssh2_pkt_addstring("en"); /* language tag */
|
|
ssh2_pkt_send();
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturnV;
|
|
}
|
|
continue; /* remote sends close; ignore (FIXME) */
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
c->v.v2.remwindow += ssh2_pkt_getuint32();
|
|
try_send = TRUE;
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
if (c->type != CHAN_SOCKDATA_DORMANT)
|
|
continue; /* dunno why they're confirming this */
|
|
c->remoteid = ssh2_pkt_getuint32();
|
|
c->type = CHAN_SOCKDATA;
|
|
c->v.v2.remwindow = ssh2_pkt_getuint32();
|
|
c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
|
|
bufchain_init(&c->v.v2.outbuffer);
|
|
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.
|
|
*/
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_send();
|
|
}
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
|
|
unsigned i = ssh2_pkt_getuint32();
|
|
struct ssh_channel *c;
|
|
c = find234(ssh_channels, &i, ssh_channelfind);
|
|
if (!c)
|
|
continue; /* nonexistent channel */
|
|
if (c->type != CHAN_SOCKDATA_DORMANT)
|
|
continue; /* dunno why they're failing this */
|
|
|
|
logevent("Forwarded connection refused by server");
|
|
|
|
pfd_close(c->u.pfd.s);
|
|
|
|
del234(ssh_channels, c);
|
|
sfree(c);
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
|
|
unsigned localid;
|
|
char *type;
|
|
int typelen, want_reply;
|
|
struct ssh_channel *c;
|
|
|
|
localid = ssh2_pkt_getuint32();
|
|
ssh2_pkt_getstring(&type, &typelen);
|
|
want_reply = ssh2_pkt_getbool();
|
|
|
|
/*
|
|
* First, check that the channel exists. Otherwise,
|
|
* we can instantly disconnect with a rude message.
|
|
*/
|
|
c = find234(ssh_channels, &localid, ssh_channelfind);
|
|
if (!c) {
|
|
char buf[80];
|
|
sprintf(buf, "Received channel request for nonexistent"
|
|
" channel %d", localid);
|
|
logevent(buf);
|
|
ssh2_pkt_init(SSH2_MSG_DISCONNECT);
|
|
ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
|
|
ssh2_pkt_addstring(buf);
|
|
ssh2_pkt_addstring("en"); /* language tag */
|
|
ssh2_pkt_send();
|
|
connection_fatal(buf);
|
|
ssh_state = SSH_STATE_CLOSED;
|
|
crReturnV;
|
|
}
|
|
|
|
/*
|
|
* We don't recognise any form of channel request,
|
|
* so we now either ignore the request or respond
|
|
* with CHANNEL_FAILURE, depending on want_reply.
|
|
*/
|
|
if (want_reply) {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_send();
|
|
}
|
|
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
|
|
char *type;
|
|
int typelen;
|
|
char *error = NULL;
|
|
struct ssh_channel *c;
|
|
unsigned remid, winsize, pktsize;
|
|
ssh2_pkt_getstring(&type, &typelen);
|
|
c = smalloc(sizeof(struct ssh_channel));
|
|
|
|
remid = ssh2_pkt_getuint32();
|
|
winsize = ssh2_pkt_getuint32();
|
|
pktsize = ssh2_pkt_getuint32();
|
|
|
|
if (typelen == 3 && !memcmp(type, "x11", 3)) {
|
|
if (!ssh_X11_fwd_enabled)
|
|
error = "X11 forwarding is not enabled";
|
|
else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
|
|
NULL) {
|
|
error = "Unable to open an X11 connection";
|
|
} else {
|
|
c->type = CHAN_X11;
|
|
}
|
|
} else if (typelen == 15 &&
|
|
!memcmp(type, "forwarded-tcpip", 15)) {
|
|
struct ssh_rportfwd pf, *realpf;
|
|
char *dummy;
|
|
int dummylen;
|
|
ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
|
|
pf.sport = ssh2_pkt_getuint32();
|
|
realpf = find234(ssh_rportfwds, &pf, NULL);
|
|
if (realpf == NULL) {
|
|
error = "Remote port is not recognised";
|
|
} else {
|
|
char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
|
|
realpf->dport, c);
|
|
char buf[1024];
|
|
sprintf(buf, "Received remote port open request for %s:%d",
|
|
realpf->dhost, realpf->dport);
|
|
logevent(buf);
|
|
if (e != NULL) {
|
|
sprintf(buf, "Port open failed: %s", e);
|
|
logevent(buf);
|
|
error = "Port open failed";
|
|
} else {
|
|
logevent("Forwarded port opened successfully");
|
|
c->type = CHAN_SOCKDATA;
|
|
}
|
|
}
|
|
} else if (typelen == 22 &&
|
|
!memcmp(type, "auth-agent@openssh.com", 3)) {
|
|
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;
|
|
if (error) {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
|
|
ssh2_pkt_addstring(error);
|
|
ssh2_pkt_addstring("en"); /* language tag */
|
|
ssh2_pkt_send();
|
|
sfree(c);
|
|
} else {
|
|
c->localid = alloc_channel_id();
|
|
c->closes = 0;
|
|
c->v.v2.locwindow = OUR_V2_WINSIZE;
|
|
c->v.v2.remwindow = winsize;
|
|
c->v.v2.remmaxpkt = pktsize;
|
|
bufchain_init(&c->v.v2.outbuffer);
|
|
add234(ssh_channels, c);
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
|
|
ssh2_pkt_adduint32(c->remoteid);
|
|
ssh2_pkt_adduint32(c->localid);
|
|
ssh2_pkt_adduint32(c->v.v2.locwindow);
|
|
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
|
|
ssh2_pkt_send();
|
|
}
|
|
} else {
|
|
bombout(("Strange packet received: type %d", pktin.type));
|
|
crReturnV;
|
|
}
|
|
} else {
|
|
/*
|
|
* We have spare data. Add it to the channel buffer.
|
|
*/
|
|
ssh2_add_channel_data(mainchan, in, inlen);
|
|
try_send = TRUE;
|
|
}
|
|
if (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++) {
|
|
int 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;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
crFinishV;
|
|
}
|
|
|
|
/*
|
|
* Handle the top-level SSH2 protocol.
|
|
*/
|
|
static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
|
|
{
|
|
if (do_ssh2_transport(in, inlen, ispkt) == 0)
|
|
return;
|
|
do_ssh2_authconn(in, inlen, ispkt);
|
|
}
|
|
|
|
/*
|
|
* Called to set up the connection.
|
|
*
|
|
* Returns an error message, or NULL on success.
|
|
*/
|
|
static char *ssh_init(char *host, int port, char **realhost)
|
|
{
|
|
char *p;
|
|
|
|
#ifdef MSCRYPTOAPI
|
|
if (crypto_startup() == 0)
|
|
return "Microsoft high encryption pack not installed!";
|
|
#endif
|
|
|
|
ssh_send_ok = 0;
|
|
ssh_editing = 0;
|
|
ssh_echoing = 0;
|
|
ssh1_throttle_count = 0;
|
|
ssh_overall_bufsize = 0;
|
|
ssh_fallback_cmd = 0;
|
|
|
|
p = connect_to_host(host, port, realhost);
|
|
if (p != NULL)
|
|
return p;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Called to send data down the Telnet connection.
|
|
*/
|
|
static int ssh_send(char *buf, int len)
|
|
{
|
|
if (s == NULL || ssh_protocol == NULL)
|
|
return 0;
|
|
|
|
ssh_protocol(buf, len, 0);
|
|
|
|
return ssh_sendbuffer();
|
|
}
|
|
|
|
/*
|
|
* Called to query the current amount of buffered stdin data.
|
|
*/
|
|
static int ssh_sendbuffer(void)
|
|
{
|
|
int override_value;
|
|
|
|
if (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 (!mainchan || mainchan->closes > 0)
|
|
return override_value;
|
|
else
|
|
return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Called to set the size of the window from SSH's POV.
|
|
*/
|
|
static void ssh_size(void)
|
|
{
|
|
switch (ssh_state) {
|
|
case SSH_STATE_BEFORE_SIZE:
|
|
case SSH_STATE_PREPACKET:
|
|
case SSH_STATE_CLOSED:
|
|
break; /* do nothing */
|
|
case SSH_STATE_INTERMED:
|
|
size_needed = TRUE; /* buffer for later */
|
|
break;
|
|
case SSH_STATE_SESSION:
|
|
if (!cfg.nopty) {
|
|
if (ssh_version == 1) {
|
|
send_packet(SSH1_CMSG_WINDOW_SIZE,
|
|
PKT_INT, rows, PKT_INT, cols,
|
|
PKT_INT, 0, PKT_INT, 0, PKT_END);
|
|
} else {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
|
|
ssh2_pkt_adduint32(mainchan->remoteid);
|
|
ssh2_pkt_addstring("window-change");
|
|
ssh2_pkt_addbool(0);
|
|
ssh2_pkt_adduint32(cols);
|
|
ssh2_pkt_adduint32(rows);
|
|
ssh2_pkt_adduint32(0);
|
|
ssh2_pkt_adduint32(0);
|
|
ssh2_pkt_send();
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send Telnet 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(Telnet_Special code)
|
|
{
|
|
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)
|
|
eof_needed = TRUE;
|
|
return;
|
|
}
|
|
if (ssh_version == 1) {
|
|
send_packet(SSH1_CMSG_EOF, PKT_END);
|
|
} else {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
|
|
ssh2_pkt_adduint32(mainchan->remoteid);
|
|
ssh2_pkt_send();
|
|
}
|
|
logevent("Sent EOF message");
|
|
} else if (code == TS_PING) {
|
|
if (ssh_state == SSH_STATE_CLOSED
|
|
|| ssh_state == SSH_STATE_PREPACKET) return;
|
|
if (ssh_version == 1) {
|
|
send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
|
|
} else {
|
|
ssh2_pkt_init(SSH2_MSG_IGNORE);
|
|
ssh2_pkt_addstring_start();
|
|
ssh2_pkt_send();
|
|
}
|
|
} else {
|
|
/* do nothing */
|
|
}
|
|
}
|
|
|
|
void *new_sock_channel(Socket s)
|
|
{
|
|
struct ssh_channel *c;
|
|
c = smalloc(sizeof(struct ssh_channel));
|
|
|
|
if (c) {
|
|
c->remoteid = -1; /* to be set when open confirmed */
|
|
c->localid = alloc_channel_id();
|
|
c->closes = 0;
|
|
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.
|
|
*/
|
|
void ssh_unthrottle(int bufsize)
|
|
{
|
|
if (ssh_version == 1) {
|
|
if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
|
|
ssh1_stdout_throttling = 0;
|
|
ssh1_throttle(-1);
|
|
}
|
|
} else {
|
|
if (mainchan && mainchan->closes == 0)
|
|
ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
|
|
}
|
|
}
|
|
|
|
void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
|
|
{
|
|
struct ssh_channel *c = (struct ssh_channel *)channel;
|
|
char buf[1024];
|
|
|
|
sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
|
|
logevent(buf);
|
|
|
|
if (ssh_version == 1) {
|
|
send_packet(SSH1_MSG_PORT_OPEN,
|
|
PKT_INT, c->localid,
|
|
PKT_STR, hostname,
|
|
PKT_INT, port,
|
|
//PKT_STR, <org:orgport>,
|
|
PKT_END);
|
|
} else {
|
|
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
|
|
ssh2_pkt_addstring("direct-tcpip");
|
|
ssh2_pkt_adduint32(c->localid);
|
|
c->v.v2.locwindow = OUR_V2_WINSIZE;
|
|
ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
|
|
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
|
|
ssh2_pkt_addstring(hostname);
|
|
ssh2_pkt_adduint32(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.
|
|
*/
|
|
ssh2_pkt_addstring("client-side-connection");
|
|
ssh2_pkt_adduint32(0);
|
|
ssh2_pkt_send();
|
|
}
|
|
}
|
|
|
|
|
|
static Socket ssh_socket(void)
|
|
{
|
|
return s;
|
|
}
|
|
|
|
static int ssh_sendok(void)
|
|
{
|
|
return ssh_send_ok;
|
|
}
|
|
|
|
static int ssh_ldisc(int option)
|
|
{
|
|
if (option == LD_ECHO)
|
|
return ssh_echoing;
|
|
if (option == LD_EDIT)
|
|
return ssh_editing;
|
|
return FALSE;
|
|
}
|
|
|
|
Backend ssh_backend = {
|
|
ssh_init,
|
|
ssh_send,
|
|
ssh_sendbuffer,
|
|
ssh_size,
|
|
ssh_special,
|
|
ssh_socket,
|
|
ssh_sendok,
|
|
ssh_ldisc,
|
|
ssh_unthrottle,
|
|
22
|
|
};
|