| /* |
| * 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 1.24 2000/04/06 02:32:40 damien Exp $"); |
| |
| #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" |
| |
| #ifdef HAVE___PROGNAME |
| extern char *__progname; |
| #else /* HAVE___PROGNAME */ |
| 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; |
| |
| 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 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, " -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, " -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; |
| |
| /* |
| * 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 '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; |
| #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 version %d.%d.\n", |
| SSH_VERSION, PROTOCOL_MAJOR, PROTOCOL_MINOR); |
| 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': |
| 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(); |
| |
| /* check if RSA support exists */ |
| if (rsa_alive() == 0) { |
| 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; |
| } |
| /* 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); |
| |
| 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) { |
| 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. |
| */ |
| |
| /* |
| * 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. */ |
| 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, (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; |
| } |
| |
| 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 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, |
| 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 */ |
| } |
| 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); |
| } |