зеркало из https://github.com/Azure/sonic-openssh.git
985 строки
28 KiB
C
985 строки
28 KiB
C
/*
|
|
* Author: Tatu Ylonen <ylo@cs.hut.fi>
|
|
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
|
|
* All rights reserved
|
|
* Created: Sat Mar 18 16:36:11 1995 ylo
|
|
* Ssh client program. This program can be used to log into a remote machine.
|
|
* The software supports strong authentication, encryption, and forwarding
|
|
* of X11, TCP/IP, and authentication connections.
|
|
*
|
|
* Modified to work with SSL by Niels Provos <provos@citi.umich.edu> in Canada.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
RCSID("$OpenBSD: ssh.c,v 1.56 2000/06/20 01:39:44 markus Exp $");
|
|
|
|
#include <openssl/evp.h>
|
|
#include <openssl/dsa.h>
|
|
#include <openssl/rsa.h>
|
|
|
|
#include "xmalloc.h"
|
|
#include "ssh.h"
|
|
#include "packet.h"
|
|
#include "buffer.h"
|
|
#include "authfd.h"
|
|
#include "readconf.h"
|
|
#include "uidswap.h"
|
|
|
|
#include "ssh2.h"
|
|
#include "compat.h"
|
|
#include "channels.h"
|
|
#include "key.h"
|
|
#include "authfile.h"
|
|
|
|
#ifdef HAVE___PROGNAME
|
|
extern char *__progname;
|
|
#else /* HAVE___PROGNAME */
|
|
static const char *__progname = "ssh";
|
|
#endif /* HAVE___PROGNAME */
|
|
|
|
/* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
|
|
Default value is AF_UNSPEC means both IPv4 and IPv6. */
|
|
#ifdef IPV4_DEFAULT
|
|
int IPv4or6 = AF_INET;
|
|
#else
|
|
int IPv4or6 = AF_UNSPEC;
|
|
#endif
|
|
|
|
/* Flag indicating whether debug mode is on. This can be set on the command line. */
|
|
int debug_flag = 0;
|
|
|
|
/* Flag indicating whether a tty should be allocated */
|
|
int tty_flag = 0;
|
|
|
|
/* don't exec a shell */
|
|
int no_shell_flag = 0;
|
|
int no_tty_flag = 0;
|
|
|
|
/*
|
|
* Flag indicating that nothing should be read from stdin. This can be set
|
|
* on the command line.
|
|
*/
|
|
int stdin_null_flag = 0;
|
|
|
|
/*
|
|
* Flag indicating that ssh should fork after authentication. This is useful
|
|
* so that the pasphrase can be entered manually, and then ssh goes to the
|
|
* background.
|
|
*/
|
|
int fork_after_authentication_flag = 0;
|
|
|
|
/*
|
|
* General data structure for command line options and options configurable
|
|
* in configuration files. See readconf.h.
|
|
*/
|
|
Options options;
|
|
|
|
/*
|
|
* Name of the host we are connecting to. This is the name given on the
|
|
* command line, or the HostName specified for the user-supplied name in a
|
|
* configuration file.
|
|
*/
|
|
char *host;
|
|
|
|
/* socket address the host resolves to */
|
|
struct sockaddr_storage hostaddr;
|
|
|
|
/*
|
|
* Flag to indicate that we have received a window change signal which has
|
|
* not yet been processed. This will cause a message indicating the new
|
|
* window size to be sent to the server a little later. This is volatile
|
|
* because this is updated in a signal handler.
|
|
*/
|
|
volatile int received_window_change_signal = 0;
|
|
|
|
/* Value of argv[0] (set in the main program). */
|
|
char *av0;
|
|
|
|
/* Flag indicating whether we have a valid host private key loaded. */
|
|
int host_private_key_loaded = 0;
|
|
|
|
/* Host private key. */
|
|
RSA *host_private_key = NULL;
|
|
|
|
/* Original real UID. */
|
|
uid_t original_real_uid;
|
|
|
|
/* command to be executed */
|
|
Buffer command;
|
|
|
|
/* Prints a help message to the user. This function never returns. */
|
|
|
|
void
|
|
usage()
|
|
{
|
|
fprintf(stderr, "Usage: %s [options] host [command]\n", av0);
|
|
fprintf(stderr, "Options:\n");
|
|
fprintf(stderr, " -l user Log in using this user name.\n");
|
|
fprintf(stderr, " -n Redirect input from /dev/null.\n");
|
|
fprintf(stderr, " -A Enable authentication agent forwarding.\n");
|
|
fprintf(stderr, " -a Disable authentication agent forwarding.\n");
|
|
#ifdef AFS
|
|
fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
|
|
#endif /* AFS */
|
|
fprintf(stderr, " -X Enable X11 connection forwarding.\n");
|
|
fprintf(stderr, " -x Disable X11 connection forwarding.\n");
|
|
fprintf(stderr, " -i file Identity for RSA authentication (default: ~/.ssh/identity).\n");
|
|
fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
|
|
fprintf(stderr, " -T Do not allocate a tty.\n");
|
|
fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
|
|
fprintf(stderr, " -V Display version number only.\n");
|
|
fprintf(stderr, " -P Don't allocate a privileged port.\n");
|
|
fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
|
|
fprintf(stderr, " -f Fork into background after authentication.\n");
|
|
fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
|
|
|
|
fprintf(stderr, " -c cipher Select encryption algorithm: "
|
|
"``3des'', "
|
|
"``blowfish''\n");
|
|
fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
|
|
fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
|
|
fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
|
|
fprintf(stderr, " These cause %s to listen for connections on a port, and\n", av0);
|
|
fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
|
|
fprintf(stderr, " -C Enable compression.\n");
|
|
fprintf(stderr, " -N Do not execute a shell or command.\n");
|
|
fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
|
|
fprintf(stderr, " -4 Use IPv4 only.\n");
|
|
fprintf(stderr, " -6 Use IPv6 only.\n");
|
|
fprintf(stderr, " -2 Force protocol version 2.\n");
|
|
fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
|
|
exit(1);
|
|
}
|
|
|
|
/*
|
|
* Connects to the given host using rsh (or prints an error message and exits
|
|
* if rsh is not available). This function never returns.
|
|
*/
|
|
void
|
|
rsh_connect(char *host, char *user, Buffer * command)
|
|
{
|
|
char *args[10];
|
|
int i;
|
|
|
|
log("Using rsh. WARNING: Connection will not be encrypted.");
|
|
/* Build argument list for rsh. */
|
|
i = 0;
|
|
args[i++] = _PATH_RSH;
|
|
/* host may have to come after user on some systems */
|
|
args[i++] = host;
|
|
if (user) {
|
|
args[i++] = "-l";
|
|
args[i++] = user;
|
|
}
|
|
if (buffer_len(command) > 0) {
|
|
buffer_append(command, "\0", 1);
|
|
args[i++] = buffer_ptr(command);
|
|
}
|
|
args[i++] = NULL;
|
|
if (debug_flag) {
|
|
for (i = 0; args[i]; i++) {
|
|
if (i != 0)
|
|
fprintf(stderr, " ");
|
|
fprintf(stderr, "%s", args[i]);
|
|
}
|
|
fprintf(stderr, "\n");
|
|
}
|
|
execv(_PATH_RSH, args);
|
|
perror(_PATH_RSH);
|
|
exit(1);
|
|
}
|
|
|
|
int ssh_session(void);
|
|
int ssh_session2(void);
|
|
|
|
/*
|
|
* Main program for the ssh client.
|
|
*/
|
|
int
|
|
main(int ac, char **av)
|
|
{
|
|
int i, opt, optind, exit_status, ok;
|
|
u_short fwd_port, fwd_host_port;
|
|
char *optarg, *cp, buf[256];
|
|
struct stat st;
|
|
struct passwd *pw, pwcopy;
|
|
int dummy;
|
|
uid_t original_effective_uid;
|
|
|
|
init_rng();
|
|
|
|
/*
|
|
* Save the original real uid. It will be needed later (uid-swapping
|
|
* may clobber the real uid).
|
|
*/
|
|
original_real_uid = getuid();
|
|
original_effective_uid = geteuid();
|
|
|
|
/* If we are installed setuid root be careful to not drop core. */
|
|
if (original_real_uid != original_effective_uid) {
|
|
struct rlimit rlim;
|
|
rlim.rlim_cur = rlim.rlim_max = 0;
|
|
if (setrlimit(RLIMIT_CORE, &rlim) < 0)
|
|
fatal("setrlimit failed: %.100s", strerror(errno));
|
|
}
|
|
/*
|
|
* Use uid-swapping to give up root privileges for the duration of
|
|
* option processing. We will re-instantiate the rights when we are
|
|
* ready to create the privileged port, and will permanently drop
|
|
* them when the port has been created (actually, when the connection
|
|
* has been made, as we may need to create the port several times).
|
|
*/
|
|
temporarily_use_uid(original_real_uid);
|
|
|
|
/*
|
|
* Set our umask to something reasonable, as some files are created
|
|
* with the default umask. This will make them world-readable but
|
|
* writable only by the owner, which is ok for all files for which we
|
|
* don't set the modes explicitly.
|
|
*/
|
|
umask(022);
|
|
|
|
/* Save our own name. */
|
|
av0 = av[0];
|
|
|
|
/* Initialize option structure to indicate that no values have been set. */
|
|
initialize_options(&options);
|
|
|
|
/* Parse command-line arguments. */
|
|
host = NULL;
|
|
|
|
/* If program name is not one of the standard names, use it as host name. */
|
|
if (strchr(av0, '/'))
|
|
cp = strrchr(av0, '/') + 1;
|
|
else
|
|
cp = av0;
|
|
if (strcmp(cp, "rsh") != 0 && strcmp(cp, "ssh") != 0 &&
|
|
strcmp(cp, "rlogin") != 0 && strcmp(cp, "slogin") != 0)
|
|
host = cp;
|
|
|
|
for (optind = 1; optind < ac; optind++) {
|
|
if (av[optind][0] != '-') {
|
|
if (host)
|
|
break;
|
|
if ((cp = strchr(av[optind], '@'))) {
|
|
if(cp == av[optind])
|
|
usage();
|
|
options.user = av[optind];
|
|
*cp = '\0';
|
|
host = ++cp;
|
|
} else
|
|
host = av[optind];
|
|
continue;
|
|
}
|
|
opt = av[optind][1];
|
|
if (!opt)
|
|
usage();
|
|
if (strchr("eilcpLRo", opt)) { /* options with arguments */
|
|
optarg = av[optind] + 2;
|
|
if (strcmp(optarg, "") == 0) {
|
|
if (optind >= ac - 1)
|
|
usage();
|
|
optarg = av[++optind];
|
|
}
|
|
} else {
|
|
if (av[optind][2])
|
|
usage();
|
|
optarg = NULL;
|
|
}
|
|
switch (opt) {
|
|
case '2':
|
|
options.protocol = SSH_PROTO_2;
|
|
break;
|
|
case '4':
|
|
IPv4or6 = AF_INET;
|
|
break;
|
|
case '6':
|
|
IPv4or6 = AF_INET6;
|
|
break;
|
|
case 'n':
|
|
stdin_null_flag = 1;
|
|
break;
|
|
case 'f':
|
|
fork_after_authentication_flag = 1;
|
|
stdin_null_flag = 1;
|
|
break;
|
|
case 'x':
|
|
options.forward_x11 = 0;
|
|
break;
|
|
case 'X':
|
|
options.forward_x11 = 1;
|
|
break;
|
|
case 'g':
|
|
options.gateway_ports = 1;
|
|
break;
|
|
case 'P':
|
|
options.use_privileged_port = 0;
|
|
break;
|
|
case 'a':
|
|
options.forward_agent = 0;
|
|
break;
|
|
case 'A':
|
|
options.forward_agent = 1;
|
|
break;
|
|
#ifdef AFS
|
|
case 'k':
|
|
options.kerberos_tgt_passing = 0;
|
|
options.afs_token_passing = 0;
|
|
break;
|
|
#endif
|
|
case 'i':
|
|
if (stat(optarg, &st) < 0) {
|
|
fprintf(stderr, "Warning: Identity file %s does not exist.\n",
|
|
optarg);
|
|
break;
|
|
}
|
|
if (options.num_identity_files >= SSH_MAX_IDENTITY_FILES)
|
|
fatal("Too many identity files specified (max %d)",
|
|
SSH_MAX_IDENTITY_FILES);
|
|
options.identity_files[options.num_identity_files++] =
|
|
xstrdup(optarg);
|
|
break;
|
|
case 't':
|
|
tty_flag = 1;
|
|
break;
|
|
case 'v':
|
|
case 'V':
|
|
fprintf(stderr, "SSH Version %s, protocol versions %d.%d/%d.%d.\n",
|
|
SSH_VERSION,
|
|
PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
|
|
PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2);
|
|
fprintf(stderr, "Compiled with SSL (0x%8.8lx).\n", SSLeay());
|
|
if (opt == 'V')
|
|
exit(0);
|
|
debug_flag = 1;
|
|
options.log_level = SYSLOG_LEVEL_DEBUG;
|
|
break;
|
|
case 'q':
|
|
options.log_level = SYSLOG_LEVEL_QUIET;
|
|
break;
|
|
case 'e':
|
|
if (optarg[0] == '^' && optarg[2] == 0 &&
|
|
(unsigned char) optarg[1] >= 64 && (unsigned char) optarg[1] < 128)
|
|
options.escape_char = (unsigned char) optarg[1] & 31;
|
|
else if (strlen(optarg) == 1)
|
|
options.escape_char = (unsigned char) optarg[0];
|
|
else if (strcmp(optarg, "none") == 0)
|
|
options.escape_char = -2;
|
|
else {
|
|
fprintf(stderr, "Bad escape character '%s'.\n", optarg);
|
|
exit(1);
|
|
}
|
|
break;
|
|
case 'c':
|
|
if (ciphers_valid(optarg)) {
|
|
/* SSH2 only */
|
|
options.ciphers = xstrdup(optarg);
|
|
options.cipher = SSH_CIPHER_ILLEGAL;
|
|
} else {
|
|
/* SSH1 only */
|
|
options.cipher = cipher_number(optarg);
|
|
if (options.cipher == -1) {
|
|
fprintf(stderr, "Unknown cipher type '%s'\n", optarg);
|
|
exit(1);
|
|
}
|
|
}
|
|
break;
|
|
case 'p':
|
|
options.port = atoi(optarg);
|
|
break;
|
|
case 'l':
|
|
options.user = optarg;
|
|
break;
|
|
case 'R':
|
|
if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf,
|
|
&fwd_host_port) != 3 &&
|
|
sscanf(optarg, "%hu:%255[^:]:%hu", &fwd_port, buf,
|
|
&fwd_host_port) != 3) {
|
|
fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
|
|
usage();
|
|
/* NOTREACHED */
|
|
}
|
|
add_remote_forward(&options, fwd_port, buf, fwd_host_port);
|
|
break;
|
|
case 'L':
|
|
if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf,
|
|
&fwd_host_port) != 3 &&
|
|
sscanf(optarg, "%hu:%255[^:]:%hu", &fwd_port, buf,
|
|
&fwd_host_port) != 3) {
|
|
fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
|
|
usage();
|
|
/* NOTREACHED */
|
|
}
|
|
add_local_forward(&options, fwd_port, buf, fwd_host_port);
|
|
break;
|
|
case 'C':
|
|
options.compression = 1;
|
|
break;
|
|
case 'N':
|
|
no_shell_flag = 1;
|
|
no_tty_flag = 1;
|
|
break;
|
|
case 'T':
|
|
no_tty_flag = 1;
|
|
break;
|
|
case 'o':
|
|
dummy = 1;
|
|
if (process_config_line(&options, host ? host : "", optarg,
|
|
"command-line", 0, &dummy) != 0)
|
|
exit(1);
|
|
break;
|
|
default:
|
|
usage();
|
|
}
|
|
}
|
|
|
|
/* Check that we got a host name. */
|
|
if (!host)
|
|
usage();
|
|
|
|
/* Initialize the command to execute on remote host. */
|
|
buffer_init(&command);
|
|
|
|
SSLeay_add_all_algorithms();
|
|
|
|
/*
|
|
* Save the command to execute on the remote host in a buffer. There
|
|
* is no limit on the length of the command, except by the maximum
|
|
* packet size. Also sets the tty flag if there is no command.
|
|
*/
|
|
if (optind == ac) {
|
|
/* No command specified - execute shell on a tty. */
|
|
tty_flag = 1;
|
|
} else {
|
|
/* A command has been specified. Store it into the
|
|
buffer. */
|
|
for (i = optind; i < ac; i++) {
|
|
if (i > optind)
|
|
buffer_append(&command, " ", 1);
|
|
buffer_append(&command, av[i], strlen(av[i]));
|
|
}
|
|
}
|
|
|
|
/* Cannot fork to background if no command. */
|
|
if (fork_after_authentication_flag && buffer_len(&command) == 0)
|
|
fatal("Cannot fork into background without a command to execute.");
|
|
|
|
/* Allocate a tty by default if no command specified. */
|
|
if (buffer_len(&command) == 0)
|
|
tty_flag = 1;
|
|
|
|
/* Do not allocate a tty if stdin is not a tty. */
|
|
if (!isatty(fileno(stdin))) {
|
|
if (tty_flag)
|
|
fprintf(stderr, "Pseudo-terminal will not be allocated because stdin is not a terminal.\n");
|
|
tty_flag = 0;
|
|
}
|
|
/* force */
|
|
if (no_tty_flag)
|
|
tty_flag = 0;
|
|
|
|
/* Get user data. */
|
|
pw = getpwuid(original_real_uid);
|
|
if (!pw) {
|
|
fprintf(stderr, "You don't exist, go away!\n");
|
|
exit(1);
|
|
}
|
|
/* Take a copy of the returned structure. */
|
|
memset(&pwcopy, 0, sizeof(pwcopy));
|
|
pwcopy.pw_name = xstrdup(pw->pw_name);
|
|
pwcopy.pw_passwd = xstrdup(pw->pw_passwd);
|
|
pwcopy.pw_uid = pw->pw_uid;
|
|
pwcopy.pw_gid = pw->pw_gid;
|
|
pwcopy.pw_dir = xstrdup(pw->pw_dir);
|
|
pwcopy.pw_shell = xstrdup(pw->pw_shell);
|
|
pw = &pwcopy;
|
|
|
|
/* Initialize "log" output. Since we are the client all output
|
|
actually goes to the terminal. */
|
|
log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0);
|
|
|
|
/* Read per-user configuration file. */
|
|
snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, SSH_USER_CONFFILE);
|
|
read_config_file(buf, host, &options);
|
|
|
|
/* Read systemwide configuration file. */
|
|
read_config_file(HOST_CONFIG_FILE, host, &options);
|
|
|
|
/* Fill configuration defaults. */
|
|
fill_default_options(&options);
|
|
|
|
/* reinit */
|
|
log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0);
|
|
|
|
/* check if RSA support exists */
|
|
if ((options.protocol & SSH_PROTO_1) &&
|
|
rsa_alive() == 0) {
|
|
log("%s: no RSA support in libssl and libcrypto. See ssl(8).",
|
|
__progname);
|
|
log("Disabling protocol version 1");
|
|
options.protocol &= ~ (SSH_PROTO_1|SSH_PROTO_1_PREFERRED);
|
|
}
|
|
if (! options.protocol & (SSH_PROTO_1|SSH_PROTO_2)) {
|
|
fprintf(stderr, "%s: No protocol version available.\n",
|
|
__progname);
|
|
exit(1);
|
|
}
|
|
|
|
if (options.user == NULL)
|
|
options.user = xstrdup(pw->pw_name);
|
|
|
|
if (options.hostname != NULL)
|
|
host = options.hostname;
|
|
|
|
/* Find canonic host name. */
|
|
if (strchr(host, '.') == 0) {
|
|
struct addrinfo hints;
|
|
struct addrinfo *ai = NULL;
|
|
int errgai;
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = IPv4or6;
|
|
hints.ai_flags = AI_CANONNAME;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
errgai = getaddrinfo(host, NULL, &hints, &ai);
|
|
if (errgai == 0) {
|
|
if (ai->ai_canonname != NULL)
|
|
host = xstrdup(ai->ai_canonname);
|
|
freeaddrinfo(ai);
|
|
}
|
|
}
|
|
/* Disable rhosts authentication if not running as root. */
|
|
if (original_effective_uid != 0 || !options.use_privileged_port) {
|
|
options.rhosts_authentication = 0;
|
|
options.rhosts_rsa_authentication = 0;
|
|
}
|
|
/*
|
|
* If using rsh has been selected, exec it now (without trying
|
|
* anything else). Note that we must release privileges first.
|
|
*/
|
|
if (options.use_rsh) {
|
|
/*
|
|
* Restore our superuser privileges. This must be done
|
|
* before permanently setting the uid.
|
|
*/
|
|
restore_uid();
|
|
|
|
/* Switch to the original uid permanently. */
|
|
permanently_set_uid(original_real_uid);
|
|
|
|
/* Execute rsh. */
|
|
rsh_connect(host, options.user, &command);
|
|
fatal("rsh_connect returned");
|
|
}
|
|
/* Restore our superuser privileges. */
|
|
restore_uid();
|
|
|
|
/*
|
|
* Open a connection to the remote host. This needs root privileges
|
|
* if rhosts_{rsa_}authentication is enabled.
|
|
*/
|
|
|
|
ok = ssh_connect(host, &hostaddr, options.port,
|
|
options.connection_attempts,
|
|
!options.rhosts_authentication &&
|
|
!options.rhosts_rsa_authentication,
|
|
original_real_uid,
|
|
options.proxy_command);
|
|
|
|
/*
|
|
* If we successfully made the connection, load the host private key
|
|
* in case we will need it later for combined rsa-rhosts
|
|
* authentication. This must be done before releasing extra
|
|
* privileges, because the file is only readable by root.
|
|
*/
|
|
if (ok && (options.protocol & SSH_PROTO_1)) {
|
|
Key k;
|
|
host_private_key = RSA_new();
|
|
k.type = KEY_RSA;
|
|
k.rsa = host_private_key;
|
|
if (load_private_key(HOST_KEY_FILE, "", &k, NULL))
|
|
host_private_key_loaded = 1;
|
|
}
|
|
/*
|
|
* Get rid of any extra privileges that we may have. We will no
|
|
* longer need them. Also, extra privileges could make it very hard
|
|
* to read identity files and other non-world-readable files from the
|
|
* user's home directory if it happens to be on a NFS volume where
|
|
* root is mapped to nobody.
|
|
*/
|
|
|
|
/*
|
|
* Note that some legacy systems need to postpone the following call
|
|
* to permanently_set_uid() until the private hostkey is destroyed
|
|
* with RSA_free(). Otherwise the calling user could ptrace() the
|
|
* process, read the private hostkey and impersonate the host.
|
|
* OpenBSD does not allow ptracing of setuid processes.
|
|
*/
|
|
permanently_set_uid(original_real_uid);
|
|
|
|
/*
|
|
* Now that we are back to our own permissions, create ~/.ssh
|
|
* directory if it doesn\'t already exist.
|
|
*/
|
|
snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, SSH_USER_DIR);
|
|
if (stat(buf, &st) < 0)
|
|
if (mkdir(buf, 0755) < 0)
|
|
error("Could not create directory '%.200s'.", buf);
|
|
|
|
/* Check if the connection failed, and try "rsh" if appropriate. */
|
|
if (!ok) {
|
|
if (options.port != 0)
|
|
log("Secure connection to %.100s on port %hu refused%.100s.",
|
|
host, options.port,
|
|
options.fallback_to_rsh ? "; reverting to insecure method" : "");
|
|
else
|
|
log("Secure connection to %.100s refused%.100s.", host,
|
|
options.fallback_to_rsh ? "; reverting to insecure method" : "");
|
|
|
|
if (options.fallback_to_rsh) {
|
|
rsh_connect(host, options.user, &command);
|
|
fatal("rsh_connect returned");
|
|
}
|
|
exit(1);
|
|
}
|
|
/* Expand ~ in options.identity_files. */
|
|
/* XXX mem-leaks */
|
|
for (i = 0; i < options.num_identity_files; i++)
|
|
options.identity_files[i] =
|
|
tilde_expand_filename(options.identity_files[i], original_real_uid);
|
|
for (i = 0; i < options.num_identity_files2; i++)
|
|
options.identity_files2[i] =
|
|
tilde_expand_filename(options.identity_files2[i], original_real_uid);
|
|
/* Expand ~ in known host file names. */
|
|
options.system_hostfile = tilde_expand_filename(options.system_hostfile,
|
|
original_real_uid);
|
|
options.user_hostfile = tilde_expand_filename(options.user_hostfile,
|
|
original_real_uid);
|
|
options.system_hostfile2 = tilde_expand_filename(options.system_hostfile2,
|
|
original_real_uid);
|
|
options.user_hostfile2 = tilde_expand_filename(options.user_hostfile2,
|
|
original_real_uid);
|
|
|
|
/* Log into the remote system. This never returns if the login fails. */
|
|
ssh_login(host_private_key_loaded, host_private_key,
|
|
host, (struct sockaddr *)&hostaddr, original_real_uid);
|
|
|
|
/* We no longer need the host private key. Clear it now. */
|
|
if (host_private_key_loaded)
|
|
RSA_free(host_private_key); /* Destroys contents safely */
|
|
|
|
exit_status = compat20 ? ssh_session2() : ssh_session();
|
|
packet_close();
|
|
return exit_status;
|
|
}
|
|
|
|
void
|
|
x11_get_proto(char *proto, int proto_len, char *data, int data_len)
|
|
{
|
|
char line[512];
|
|
FILE *f;
|
|
int got_data = 0, i;
|
|
|
|
if (options.xauth_location) {
|
|
/* Try to get Xauthority information for the display. */
|
|
snprintf(line, sizeof line, "%.100s list %.200s 2>/dev/null",
|
|
options.xauth_location, getenv("DISPLAY"));
|
|
f = popen(line, "r");
|
|
if (f && fgets(line, sizeof(line), f) &&
|
|
sscanf(line, "%*s %s %s", proto, data) == 2)
|
|
got_data = 1;
|
|
if (f)
|
|
pclose(f);
|
|
}
|
|
/*
|
|
* If we didn't get authentication data, just make up some
|
|
* data. The forwarding code will check the validity of the
|
|
* response anyway, and substitute this data. The X11
|
|
* server, however, will ignore this fake data and use
|
|
* whatever authentication mechanisms it was using otherwise
|
|
* for the local connection.
|
|
*/
|
|
if (!got_data) {
|
|
u_int32_t rand = 0;
|
|
|
|
strlcpy(proto, "MIT-MAGIC-COOKIE-1", proto_len);
|
|
for (i = 0; i < 16; i++) {
|
|
if (i % 4 == 0)
|
|
rand = arc4random();
|
|
snprintf(data + 2 * i, data_len - 2 * i, "%02x", rand & 0xff);
|
|
rand >>= 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
int
|
|
ssh_session(void)
|
|
{
|
|
int type;
|
|
int i;
|
|
int plen;
|
|
int interactive = 0;
|
|
int have_tty = 0;
|
|
struct winsize ws;
|
|
int authfd;
|
|
char *cp;
|
|
|
|
/* Enable compression if requested. */
|
|
if (options.compression) {
|
|
debug("Requesting compression at level %d.", options.compression_level);
|
|
|
|
if (options.compression_level < 1 || options.compression_level > 9)
|
|
fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
|
|
|
|
/* Send the request. */
|
|
packet_start(SSH_CMSG_REQUEST_COMPRESSION);
|
|
packet_put_int(options.compression_level);
|
|
packet_send();
|
|
packet_write_wait();
|
|
type = packet_read(&plen);
|
|
if (type == SSH_SMSG_SUCCESS)
|
|
packet_start_compression(options.compression_level);
|
|
else if (type == SSH_SMSG_FAILURE)
|
|
log("Warning: Remote host refused compression.");
|
|
else
|
|
packet_disconnect("Protocol error waiting for compression response.");
|
|
}
|
|
/* Allocate a pseudo tty if appropriate. */
|
|
if (tty_flag) {
|
|
debug("Requesting pty.");
|
|
|
|
/* Start the packet. */
|
|
packet_start(SSH_CMSG_REQUEST_PTY);
|
|
|
|
/* Store TERM in the packet. There is no limit on the
|
|
length of the string. */
|
|
cp = getenv("TERM");
|
|
if (!cp)
|
|
cp = "";
|
|
packet_put_string(cp, strlen(cp));
|
|
|
|
/* Store window size in the packet. */
|
|
if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
|
|
memset(&ws, 0, sizeof(ws));
|
|
packet_put_int(ws.ws_row);
|
|
packet_put_int(ws.ws_col);
|
|
packet_put_int(ws.ws_xpixel);
|
|
packet_put_int(ws.ws_ypixel);
|
|
|
|
/* Store tty modes in the packet. */
|
|
tty_make_modes(fileno(stdin));
|
|
|
|
/* Send the packet, and wait for it to leave. */
|
|
packet_send();
|
|
packet_write_wait();
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read(&plen);
|
|
if (type == SSH_SMSG_SUCCESS) {
|
|
interactive = 1;
|
|
have_tty = 1;
|
|
} else if (type == SSH_SMSG_FAILURE)
|
|
log("Warning: Remote host failed or refused to allocate a pseudo tty.");
|
|
else
|
|
packet_disconnect("Protocol error waiting for pty request response.");
|
|
}
|
|
/* Request X11 forwarding if enabled and DISPLAY is set. */
|
|
if (options.forward_x11 && getenv("DISPLAY") != NULL) {
|
|
char proto[512], data[512];
|
|
/* Get reasonable local authentication information. */
|
|
x11_get_proto(proto, sizeof proto, data, sizeof data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication spoofing.");
|
|
x11_request_forwarding_with_spoofing(0, proto, data);
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read(&plen);
|
|
if (type == SSH_SMSG_SUCCESS) {
|
|
interactive = 1;
|
|
} else if (type == SSH_SMSG_FAILURE) {
|
|
log("Warning: Remote host denied X11 forwarding.");
|
|
} else {
|
|
packet_disconnect("Protocol error waiting for X11 forwarding");
|
|
}
|
|
}
|
|
/* Tell the packet module whether this is an interactive session. */
|
|
packet_set_interactive(interactive, options.keepalives);
|
|
|
|
/* Clear agent forwarding if we don\'t have an agent. */
|
|
authfd = ssh_get_authentication_socket();
|
|
if (authfd < 0)
|
|
options.forward_agent = 0;
|
|
else
|
|
ssh_close_authentication_socket(authfd);
|
|
|
|
/* Request authentication agent forwarding if appropriate. */
|
|
if (options.forward_agent) {
|
|
debug("Requesting authentication agent forwarding.");
|
|
auth_request_forwarding();
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read(&plen);
|
|
packet_integrity_check(plen, 0, type);
|
|
if (type != SSH_SMSG_SUCCESS)
|
|
log("Warning: Remote host denied authentication agent forwarding.");
|
|
}
|
|
/* Initiate local TCP/IP port forwardings. */
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
debug("Connections to local port %d forwarded to remote address %.200s:%d",
|
|
options.local_forwards[i].port,
|
|
options.local_forwards[i].host,
|
|
options.local_forwards[i].host_port);
|
|
channel_request_local_forwarding(options.local_forwards[i].port,
|
|
options.local_forwards[i].host,
|
|
options.local_forwards[i].host_port,
|
|
options.gateway_ports);
|
|
}
|
|
|
|
/* Initiate remote TCP/IP port forwardings. */
|
|
for (i = 0; i < options.num_remote_forwards; i++) {
|
|
debug("Connections to remote port %d forwarded to local address %.200s:%d",
|
|
options.remote_forwards[i].port,
|
|
options.remote_forwards[i].host,
|
|
options.remote_forwards[i].host_port);
|
|
channel_request_remote_forwarding(options.remote_forwards[i].port,
|
|
options.remote_forwards[i].host,
|
|
options.remote_forwards[i].host_port);
|
|
}
|
|
|
|
/* If requested, let ssh continue in the background. */
|
|
if (fork_after_authentication_flag)
|
|
if (daemon(1, 1) < 0)
|
|
fatal("daemon() failed: %.200s", strerror(errno));
|
|
|
|
/*
|
|
* If a command was specified on the command line, execute the
|
|
* command now. Otherwise request the server to start a shell.
|
|
*/
|
|
if (buffer_len(&command) > 0) {
|
|
int len = buffer_len(&command);
|
|
if (len > 900)
|
|
len = 900;
|
|
debug("Sending command: %.*s", len, buffer_ptr(&command));
|
|
packet_start(SSH_CMSG_EXEC_CMD);
|
|
packet_put_string(buffer_ptr(&command), buffer_len(&command));
|
|
packet_send();
|
|
packet_write_wait();
|
|
} else {
|
|
debug("Requesting shell.");
|
|
packet_start(SSH_CMSG_EXEC_SHELL);
|
|
packet_send();
|
|
packet_write_wait();
|
|
}
|
|
|
|
/* Enter the interactive session. */
|
|
return client_loop(have_tty, tty_flag ? options.escape_char : -1);
|
|
}
|
|
|
|
void
|
|
init_local_fwd(void)
|
|
{
|
|
int i;
|
|
/* Initiate local TCP/IP port forwardings. */
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
debug("Connections to local port %d forwarded to remote address %.200s:%d",
|
|
options.local_forwards[i].port,
|
|
options.local_forwards[i].host,
|
|
options.local_forwards[i].host_port);
|
|
channel_request_local_forwarding(options.local_forwards[i].port,
|
|
options.local_forwards[i].host,
|
|
options.local_forwards[i].host_port,
|
|
options.gateway_ports);
|
|
}
|
|
}
|
|
|
|
extern void client_set_session_ident(int id);
|
|
|
|
void
|
|
client_init(int id, void *arg)
|
|
{
|
|
int len;
|
|
debug("client_init id %d arg %d", id, (int)arg);
|
|
|
|
if (no_shell_flag)
|
|
goto done;
|
|
|
|
if (tty_flag) {
|
|
struct winsize ws;
|
|
char *cp;
|
|
cp = getenv("TERM");
|
|
if (!cp)
|
|
cp = "";
|
|
/* Store window size in the packet. */
|
|
if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
|
|
memset(&ws, 0, sizeof(ws));
|
|
|
|
channel_request_start(id, "pty-req", 0);
|
|
packet_put_cstring(cp);
|
|
packet_put_int(ws.ws_col);
|
|
packet_put_int(ws.ws_row);
|
|
packet_put_int(ws.ws_xpixel);
|
|
packet_put_int(ws.ws_ypixel);
|
|
packet_put_cstring(""); /* XXX: encode terminal modes */
|
|
packet_send();
|
|
/* XXX wait for reply */
|
|
}
|
|
if (options.forward_x11 &&
|
|
getenv("DISPLAY") != NULL) {
|
|
char proto[512], data[512];
|
|
/* Get reasonable local authentication information. */
|
|
x11_get_proto(proto, sizeof proto, data, sizeof data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication spoofing.");
|
|
x11_request_forwarding_with_spoofing(id, proto, data);
|
|
/* XXX wait for reply */
|
|
}
|
|
|
|
len = buffer_len(&command);
|
|
if (len > 0) {
|
|
if (len > 900)
|
|
len = 900;
|
|
debug("Sending command: %.*s", len, buffer_ptr(&command));
|
|
channel_request_start(id, "exec", 0);
|
|
packet_put_string(buffer_ptr(&command), len);
|
|
packet_send();
|
|
} else {
|
|
channel_request(id, "shell", 0);
|
|
}
|
|
/* channel_callback(id, SSH2_MSG_OPEN_CONFIGMATION, client_init, 0); */
|
|
done:
|
|
/* register different callback, etc. XXX */
|
|
client_set_session_ident(id);
|
|
}
|
|
|
|
int
|
|
ssh_session2(void)
|
|
{
|
|
int window, packetmax, id;
|
|
int in = dup(STDIN_FILENO);
|
|
int out = dup(STDOUT_FILENO);
|
|
int err = dup(STDERR_FILENO);
|
|
|
|
if (in < 0 || out < 0 || err < 0)
|
|
fatal("dump in/out/err failed");
|
|
|
|
/* should be pre-session */
|
|
init_local_fwd();
|
|
|
|
window = 32*1024;
|
|
if (tty_flag) {
|
|
packetmax = window/8;
|
|
} else {
|
|
window *= 2;
|
|
packetmax = window/2;
|
|
}
|
|
|
|
id = channel_new(
|
|
"session", SSH_CHANNEL_OPENING, in, out, err,
|
|
window, packetmax, CHAN_EXTENDED_WRITE, xstrdup("client-session"));
|
|
|
|
|
|
channel_open(id);
|
|
channel_register_callback(id, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, client_init, (void *)0);
|
|
|
|
return client_loop(tty_flag, tty_flag ? options.escape_char : -1);
|
|
}
|