mirror of
git://anongit.mindrot.org/openssh.git
synced 2024-12-23 18:32:26 +00:00
1e4772c32c
nchan.ms -\ channels.[ch] - remove broken x11 fix and document istate/ostate ssh-agent.c - call setsid() regardless of argv[] ssh.c - save a few lines when disabling rhosts-{rsa-}auth
802 lines
24 KiB
C
802 lines
24 KiB
C
/*
|
|
|
|
ssh.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("$Id: ssh.c,v 1.4 1999/10/30 01:39:56 damien Exp $");
|
|
|
|
#include "xmalloc.h"
|
|
#include "ssh.h"
|
|
#include "packet.h"
|
|
#include "buffer.h"
|
|
#include "authfd.h"
|
|
#include "readconf.h"
|
|
#include "uidswap.h"
|
|
|
|
/* Flag indicating whether debug mode is on. This can be set on the
|
|
command line. */
|
|
int debug_flag = 0;
|
|
|
|
/* Flag indicating whether quiet mode is on. */
|
|
int quiet_flag = 0;
|
|
|
|
/* Flag indicating whether to allocate a pseudo tty. This can be set on the
|
|
command line, and is automatically set if no command is given on the command
|
|
line. */
|
|
int 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_in 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;
|
|
|
|
/* 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 Disable authentication agent forwarding.\n");
|
|
#ifdef AFS
|
|
fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
|
|
#endif /* AFS */
|
|
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, " -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, " -g Allow remote hosts to connect to forwarded ports.\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;
|
|
args[i++] = host; /* may have to come after user on some systems */
|
|
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);
|
|
}
|
|
|
|
/* Main program for the ssh client. */
|
|
|
|
int
|
|
main(int ac, char **av)
|
|
{
|
|
int i, opt, optind, type, exit_status, ok, fwd_port, fwd_host_port, authfd;
|
|
char *optarg, *cp, buf[256];
|
|
Buffer command;
|
|
struct winsize ws;
|
|
struct stat st;
|
|
struct passwd *pw, pwcopy;
|
|
int interactive = 0, dummy;
|
|
uid_t original_effective_uid;
|
|
int plen;
|
|
|
|
/* 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], '@'))) {
|
|
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 '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;
|
|
#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':
|
|
debug_flag = 1;
|
|
fprintf(stderr, "SSH Version %s, protocol version %d.%d.\n",
|
|
SSH_VERSION, PROTOCOL_MAJOR, PROTOCOL_MINOR);
|
|
fprintf(stderr, "Compiled with SSL.\n");
|
|
if (opt == 'V')
|
|
exit(0);
|
|
break;
|
|
|
|
case 'q':
|
|
quiet_flag = 1;
|
|
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':
|
|
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);
|
|
if (options.port < 1 || options.port > 65535)
|
|
{
|
|
fprintf(stderr, "Bad port %s.\n", optarg);
|
|
exit(1);
|
|
}
|
|
break;
|
|
|
|
case 'l':
|
|
options.user = optarg;
|
|
break;
|
|
|
|
case 'R':
|
|
if (sscanf(optarg, "%d:%255[^:]:%d", &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, "%d:%255[^:]:%d", &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 'o':
|
|
dummy = 1;
|
|
process_config_line(&options, host ? host : "", optarg,
|
|
"command-line", 0, &dummy);
|
|
break;
|
|
|
|
default:
|
|
usage();
|
|
}
|
|
}
|
|
|
|
/* Check that we got a host name. */
|
|
if (!host)
|
|
usage();
|
|
|
|
/* check if RSA support exists */
|
|
if (rsa_alive() == 0) {
|
|
extern char *__progname;
|
|
|
|
fprintf(stderr,
|
|
"%s: no RSA support in libssl and libcrypto. See ssl(8).\n",
|
|
__progname);
|
|
exit(1);
|
|
}
|
|
|
|
/* Initialize the command to execute on remote host. */
|
|
buffer_init(&command);
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* 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], 1, debug_flag, quiet_flag, SYSLOG_FACILITY_USER);
|
|
|
|
/* 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);
|
|
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 hostent *hp = gethostbyname(host);
|
|
if (hp != 0)
|
|
{
|
|
if (strchr(hp->h_name, '.') != 0)
|
|
host = xstrdup(hp->h_name);
|
|
else if (hp->h_aliases != 0
|
|
&& hp->h_aliases[0] != 0
|
|
&& strchr(hp->h_aliases[0], '.') != 0)
|
|
host = xstrdup(hp->h_aliases[0]);
|
|
}
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
host_private_key = RSA_new();
|
|
if (load_private_key(HOST_KEY_FILE, "", host_private_key, 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. */
|
|
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 %d 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. */
|
|
for (i = 0; i < options.num_identity_files; i++)
|
|
options.identity_files[i] =
|
|
tilde_expand_filename(options.identity_files[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);
|
|
|
|
/* Log into the remote system. This never returns if the login fails. */
|
|
ssh_login(host_private_key_loaded, host_private_key,
|
|
host, &hostaddr, &options, 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 */
|
|
|
|
/* Close connection cleanly after attack. */
|
|
cipher_attack_detected = packet_disconnect;
|
|
|
|
/* If requested, fork and let ssh continue in the background. */
|
|
if (fork_after_authentication_flag)
|
|
{
|
|
int ret = fork();
|
|
if (ret == -1)
|
|
fatal("fork failed: %.100s", strerror(errno));
|
|
if (ret != 0)
|
|
exit(0);
|
|
setsid();
|
|
}
|
|
|
|
/* 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;
|
|
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 line[512], proto[512], data[512];
|
|
FILE *f;
|
|
int forwarded = 0, got_data = 0, i;
|
|
|
|
#ifdef XAUTH_PATH
|
|
/* Try to get Xauthority information for the display. */
|
|
snprintf(line, sizeof line, "%.100s list %.200s 2>/dev/null",
|
|
XAUTH_PATH, 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);
|
|
#endif /* XAUTH_PATH */
|
|
/* 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", sizeof proto);
|
|
for (i = 0; i < 16; i++) {
|
|
if (i % 4 == 0)
|
|
rand = arc4random();
|
|
snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", rand & 0xff);
|
|
rand >>= 8;
|
|
}
|
|
}
|
|
|
|
/* Got local authentication reasonable information. Request forwarding
|
|
with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication spoofing.");
|
|
x11_request_forwarding_with_spoofing(proto, data);
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read(&plen);
|
|
if (type == SSH_SMSG_SUCCESS)
|
|
{
|
|
forwarded = 1;
|
|
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);
|
|
}
|
|
|
|
/* 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 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. */
|
|
exit_status = client_loop(tty_flag, tty_flag ? options.escape_char : -1);
|
|
|
|
/* Close the connection to the remote host. */
|
|
packet_close();
|
|
|
|
/* Exit with the status returned by the program on the remote side. */
|
|
exit(exit_status);
|
|
}
|