| /* |
| * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| * All rights reserved |
| * 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. |
| * |
| * As far as I am concerned, the code I have written for this software |
| * can be used freely for any purpose. Any derived versions of this |
| * software must be clearly marked as such, and if the derived work is |
| * incompatible with the protocol description in the RFC file, it must be |
| * called by a name other than "ssh" or "Secure Shell". |
| * |
| * Copyright (c) 1999 Niels Provos. All rights reserved. |
| * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved. |
| * |
| * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> |
| * in Canada (German citizen). |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "includes.h" |
| RCSID("$OpenBSD: ssh.c,v 1.169 2002/03/26 11:37:05 markus Exp $"); |
| |
| #include <openssl/evp.h> |
| #include <openssl/err.h> |
| |
| #include "ssh.h" |
| #include "ssh1.h" |
| #include "ssh2.h" |
| #include "compat.h" |
| #include "cipher.h" |
| #include "xmalloc.h" |
| #include "packet.h" |
| #include "buffer.h" |
| #include "uidswap.h" |
| #include "channels.h" |
| #include "key.h" |
| #include "authfd.h" |
| #include "authfile.h" |
| #include "pathnames.h" |
| #include "clientloop.h" |
| #include "log.h" |
| #include "readconf.h" |
| #include "sshconnect.h" |
| #include "tildexpand.h" |
| #include "dispatch.h" |
| #include "misc.h" |
| #include "kex.h" |
| #include "mac.h" |
| #include "sshtty.h" |
| |
| #ifdef SMARTCARD |
| #include "scard.h" |
| #endif |
| |
| #ifdef HAVE___PROGNAME |
| extern char *__progname; |
| #else |
| char *__progname; |
| #endif |
| |
| /* 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; |
| int no_tty_flag = 0; |
| int force_tty_flag = 0; |
| |
| /* don't exec a shell */ |
| int no_shell_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; |
| |
| /* optional user configfile */ |
| char *config = NULL; |
| |
| /* |
| * 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; |
| |
| /* Private host keys. */ |
| struct { |
| Key **keys; |
| int nkeys; |
| } sensitive_data; |
| |
| /* Original real UID. */ |
| uid_t original_real_uid; |
| |
| /* command to be executed */ |
| Buffer command; |
| |
| /* Should we execute a command or invoke a subsystem? */ |
| int subsystem_flag = 0; |
| |
| /* Prints a help message to the user. This function never returns. */ |
| |
| static void |
| usage(void) |
| { |
| fprintf(stderr, "Usage: %s [options] host [command]\n", __progname); |
| fprintf(stderr, "Options:\n"); |
| fprintf(stderr, " -l user Log in using this user name.\n"); |
| fprintf(stderr, " -n Redirect input from " _PATH_DEVNULL ".\n"); |
| fprintf(stderr, " -F config Config file (default: ~/%s).\n", |
| _PATH_SSH_USER_CONFFILE); |
| fprintf(stderr, " -A Enable authentication agent forwarding.\n"); |
| fprintf(stderr, " -a Disable authentication agent forwarding (default).\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 (default).\n"); |
| fprintf(stderr, " -i file Identity for public key authentication " |
| "(default: ~/.ssh/identity)\n"); |
| #ifdef SMARTCARD |
| fprintf(stderr, " -I reader Set smartcard reader.\n"); |
| #endif |
| 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, " Multiple -v increases verbosity.\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\n"); |
| fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\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", __progname); |
| fprintf(stderr, " forward them to the other side by connecting to host:port.\n"); |
| fprintf(stderr, " -D port Enable dynamic application-level port forwarding.\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, " -1 Force protocol version 1.\n"); |
| fprintf(stderr, " -2 Force protocol version 2.\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"); |
| fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n"); |
| fprintf(stderr, " -b addr Local IP address.\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. |
| */ |
| static 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); |
| } |
| |
| static int ssh_session(void); |
| static int ssh_session2(void); |
| static void load_public_identity_files(void); |
| |
| /* |
| * Main program for the ssh client. |
| */ |
| int |
| main(int ac, char **av) |
| { |
| int i, opt, exit_status, cerr; |
| u_short fwd_port, fwd_host_port; |
| char sfwd_port[6], sfwd_host_port[6]; |
| char *p, *cp, buf[256]; |
| struct stat st; |
| struct passwd *pw; |
| int dummy; |
| uid_t original_effective_uid; |
| extern int optind, optreset; |
| extern char *optarg; |
| |
| __progname = get_progname(av[0]); |
| 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(); |
| |
| #ifdef HAVE_SETRLIMIT |
| /* 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)); |
| } |
| #endif |
| /* Get user data. */ |
| pw = getpwuid(original_real_uid); |
| if (!pw) { |
| log("You don't exist, go away!"); |
| exit(1); |
| } |
| /* Take a copy of the returned structure. */ |
| pw = pwcopy(pw); |
| |
| /* |
| * 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(pw); |
| |
| /* |
| * 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); |
| |
| /* Initialize option structure to indicate that no values have been set. */ |
| initialize_options(&options); |
| |
| /* Parse command-line arguments. */ |
| host = NULL; |
| |
| again: |
| while ((opt = getopt(ac, av, |
| "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:NPR:TVX")) != -1) { |
| switch (opt) { |
| case '1': |
| options.protocol = SSH_PROTO_1; |
| break; |
| 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 'I': |
| #ifdef SMARTCARD |
| options.smartcard_device = xstrdup(optarg); |
| #else |
| fprintf(stderr, "no support for smartcards.\n"); |
| #endif |
| break; |
| case 't': |
| if (tty_flag) |
| force_tty_flag = 1; |
| tty_flag = 1; |
| break; |
| case 'v': |
| if (0 == debug_flag) { |
| debug_flag = 1; |
| options.log_level = SYSLOG_LEVEL_DEBUG1; |
| } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) { |
| options.log_level++; |
| break; |
| } else |
| fatal("Too high debugging level."); |
| /* fallthrough */ |
| case 'V': |
| fprintf(stderr, |
| "%s, SSH protocols %d.%d/%d.%d, OpenSSL 0x%8.8lx\n", |
| SSH_VERSION, |
| PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1, |
| PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, |
| SSLeay()); |
| if (opt == 'V') |
| exit(0); |
| break; |
| case 'q': |
| options.log_level = SYSLOG_LEVEL_QUIET; |
| break; |
| case 'e': |
| if (optarg[0] == '^' && optarg[2] == 0 && |
| (u_char) optarg[1] >= 64 && |
| (u_char) optarg[1] < 128) |
| options.escape_char = (u_char) optarg[1] & 31; |
| else if (strlen(optarg) == 1) |
| options.escape_char = (u_char) optarg[0]; |
| else if (strcmp(optarg, "none") == 0) |
| options.escape_char = SSH_ESCAPECHAR_NONE; |
| 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); |
| } |
| if (options.cipher == SSH_CIPHER_3DES) |
| options.ciphers = "3des-cbc"; |
| else if (options.cipher == SSH_CIPHER_BLOWFISH) |
| options.ciphers = "blowfish-cbc"; |
| else |
| options.ciphers = (char *)-1; |
| } |
| break; |
| case 'm': |
| if (mac_valid(optarg)) |
| options.macs = xstrdup(optarg); |
| else { |
| fprintf(stderr, "Unknown mac type '%s'\n", |
| optarg); |
| exit(1); |
| } |
| break; |
| case 'p': |
| options.port = a2port(optarg); |
| if (options.port == 0) { |
| fprintf(stderr, "Bad port '%s'\n", optarg); |
| exit(1); |
| } |
| break; |
| case 'l': |
| options.user = optarg; |
| break; |
| |
| case 'L': |
| case 'R': |
| if (sscanf(optarg, "%5[0-9]:%255[^:]:%5[0-9]", |
| sfwd_port, buf, sfwd_host_port) != 3 && |
| sscanf(optarg, "%5[0-9]/%255[^/]/%5[0-9]", |
| sfwd_port, buf, sfwd_host_port) != 3) { |
| fprintf(stderr, |
| "Bad forwarding specification '%s'\n", |
| optarg); |
| usage(); |
| /* NOTREACHED */ |
| } |
| if ((fwd_port = a2port(sfwd_port)) == 0 || |
| (fwd_host_port = a2port(sfwd_host_port)) == 0) { |
| fprintf(stderr, |
| "Bad forwarding port(s) '%s'\n", optarg); |
| exit(1); |
| } |
| if (opt == 'L') |
| add_local_forward(&options, fwd_port, buf, |
| fwd_host_port); |
| else if (opt == 'R') |
| add_remote_forward(&options, fwd_port, buf, |
| fwd_host_port); |
| break; |
| |
| case 'D': |
| fwd_port = a2port(optarg); |
| if (fwd_port == 0) { |
| fprintf(stderr, "Bad dynamic port '%s'\n", |
| optarg); |
| exit(1); |
| } |
| add_local_forward(&options, fwd_port, "socks4", 0); |
| 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; |
| case 's': |
| subsystem_flag = 1; |
| break; |
| case 'b': |
| options.bind_address = optarg; |
| break; |
| case 'F': |
| config = optarg; |
| break; |
| default: |
| usage(); |
| } |
| } |
| |
| ac -= optind; |
| av += optind; |
| |
| if (ac > 0 && !host && **av != '-') { |
| if (strchr(*av, '@')) { |
| p = xstrdup(*av); |
| cp = strchr(p, '@'); |
| if (cp == NULL || cp == p) |
| usage(); |
| options.user = p; |
| *cp = '\0'; |
| host = ++cp; |
| } else |
| host = *av; |
| ac--, av++; |
| if (ac > 0) { |
| optind = 0; |
| optreset = 1; |
| goto again; |
| } |
| } |
| |
| /* Check that we got a host name. */ |
| if (!host) |
| usage(); |
| |
| SSLeay_add_all_algorithms(); |
| ERR_load_crypto_strings(); |
| channel_set_af(IPv4or6); |
| |
| /* 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 (!ac) { |
| /* No command specified - execute shell on a tty. */ |
| tty_flag = 1; |
| if (subsystem_flag) { |
| fprintf(stderr, |
| "You must specify a subsystem to invoke.\n"); |
| usage(); |
| } |
| } else { |
| /* A command has been specified. Store it into the buffer. */ |
| for (i = 0; i < ac; i++) { |
| if (i) |
| 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 && !no_shell_flag) |
| 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; |
| |
| /* Force no tty*/ |
| if (no_tty_flag) |
| tty_flag = 0; |
| /* Do not allocate a tty if stdin is not a tty. */ |
| if (!isatty(fileno(stdin)) && !force_tty_flag) { |
| if (tty_flag) |
| log("Pseudo-terminal will not be allocated because stdin is not a terminal."); |
| tty_flag = 0; |
| } |
| |
| /* |
| * Initialize "log" output. Since we are the client all output |
| * actually goes to stderr. |
| */ |
| log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, |
| SYSLOG_FACILITY_USER, 1); |
| |
| /* |
| * Read per-user configuration file. Ignore the system wide config |
| * file if the user specifies a config file on the command line. |
| */ |
| if (config != NULL) { |
| if (!read_config_file(config, host, &options)) |
| fatal("Can't open user config file %.100s: " |
| "%.100s", config, strerror(errno)); |
| } else { |
| snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, |
| _PATH_SSH_USER_CONFFILE); |
| (void)read_config_file(buf, host, &options); |
| |
| /* Read systemwide configuration file after use config. */ |
| (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, &options); |
| } |
| |
| /* Fill configuration defaults. */ |
| fill_default_options(&options); |
| |
| /* reinit */ |
| log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); |
| |
| seed_rng(); |
| |
| if (options.user == NULL) |
| options.user = xstrdup(pw->pw_name); |
| |
| if (options.hostname != NULL) |
| host = options.hostname; |
| |
| /* Disable rhosts authentication if not running as root. */ |
| #ifdef HAVE_CYGWIN |
| /* Ignore uid if running under Windows */ |
| if (!options.use_privileged_port) { |
| #else |
| if (original_effective_uid != 0 || !options.use_privileged_port) { |
| #endif |
| debug("Rhosts Authentication disabled, " |
| "originating port will not be trusted."); |
| options.rhosts_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(pw); |
| |
| /* 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. */ |
| |
| cerr = ssh_connect(host, &hostaddr, options.port, IPv4or6, |
| options.connection_attempts, |
| original_effective_uid != 0 || !options.use_privileged_port, |
| pw, 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. |
| */ |
| sensitive_data.nkeys = 0; |
| sensitive_data.keys = NULL; |
| if (!cerr && (options.rhosts_rsa_authentication || |
| options.hostbased_authentication)) { |
| sensitive_data.nkeys = 3; |
| sensitive_data.keys = xmalloc(sensitive_data.nkeys*sizeof(Key)); |
| sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, |
| _PATH_HOST_KEY_FILE, "", NULL); |
| sensitive_data.keys[1] = key_load_private_type(KEY_DSA, |
| _PATH_HOST_DSA_KEY_FILE, "", NULL); |
| sensitive_data.keys[2] = key_load_private_type(KEY_RSA, |
| _PATH_HOST_RSA_KEY_FILE, "", NULL); |
| } |
| /* |
| * 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(pw); |
| |
| /* |
| * Now that we are back to our own permissions, create ~/.ssh |
| * directory if it doesn\'t already exist. |
| */ |
| snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); |
| if (stat(buf, &st) < 0) |
| if (mkdir(buf, 0700) < 0) |
| error("Could not create directory '%.200s'.", buf); |
| |
| /* Check if the connection failed, and try "rsh" if appropriate. */ |
| if (cerr) { |
| if (!options.fallback_to_rsh) |
| exit(1); |
| if (options.port != 0) |
| log("Secure connection to %.100s on port %hu refused; " |
| "reverting to insecure method", |
| host, options.port); |
| else |
| log("Secure connection to %.100s refused; " |
| "reverting to insecure method.", host); |
| |
| rsh_connect(host, options.user, &command); |
| fatal("rsh_connect returned"); |
| } |
| /* load options.identity_files */ |
| load_public_identity_files(); |
| |
| /* Expand ~ in known host file names. */ |
| /* XXX mem-leaks: */ |
| 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); |
| |
| signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ |
| |
| /* Log into the remote system. This never returns if the login fails. */ |
| ssh_login(sensitive_data.keys, sensitive_data.nkeys, |
| host, (struct sockaddr *)&hostaddr, pw); |
| |
| /* We no longer need the private host keys. Clear them now. */ |
| if (sensitive_data.nkeys != 0) { |
| for (i = 0; i < sensitive_data.nkeys; i++) { |
| if (sensitive_data.keys[i] != NULL) { |
| /* Destroys contents safely */ |
| debug3("clear hostkey %d", i); |
| key_free(sensitive_data.keys[i]); |
| sensitive_data.keys[i] = NULL; |
| } |
| } |
| xfree(sensitive_data.keys); |
| } |
| for (i = 0; i < options.num_identity_files; i++) { |
| if (options.identity_files[i]) { |
| xfree(options.identity_files[i]); |
| options.identity_files[i] = NULL; |
| } |
| if (options.identity_keys[i]) { |
| key_free(options.identity_keys[i]); |
| options.identity_keys[i] = NULL; |
| } |
| } |
| |
| exit_status = compat20 ? ssh_session2() : ssh_session(); |
| packet_close(); |
| return exit_status; |
| } |
| |
| static void |
| x11_get_proto(char **_proto, char **_data) |
| { |
| char line[512]; |
| static char proto[512], data[512]; |
| FILE *f; |
| int got_data = 0, i; |
| char *display; |
| |
| *_proto = proto; |
| *_data = data; |
| proto[0] = data[0] = '\0'; |
| if (options.xauth_location && (display = getenv("DISPLAY"))) { |
| /* Try to get Xauthority information for the display. */ |
| if (strncmp(display, "localhost:", 10) == 0) |
| /* |
| * Handle FamilyLocal case where $DISPLAY does |
| * not match an authorization entry. For this we |
| * just try "xauth list unix:displaynum.screennum". |
| * XXX: "localhost" match to determine FamilyLocal |
| * is not perfect. |
| */ |
| snprintf(line, sizeof line, "%.100s list unix:%s 2>" |
| _PATH_DEVNULL, options.xauth_location, display+10); |
| else |
| snprintf(line, sizeof line, "%.100s list %.200s 2>" |
| _PATH_DEVNULL, options.xauth_location, display); |
| debug2("x11_get_proto %s", line); |
| f = popen(line, "r"); |
| if (f && fgets(line, sizeof(line), f) && |
| sscanf(line, "%*s %511s %511s", 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", 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; |
| } |
| } |
| } |
| |
| static void |
| ssh_init_forwarding(void) |
| { |
| int success = 0; |
| 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); |
| success += channel_setup_local_fwd_listener( |
| options.local_forwards[i].port, |
| options.local_forwards[i].host, |
| options.local_forwards[i].host_port, |
| options.gateway_ports); |
| } |
| if (i > 0 && success == 0) |
| error("Could not request local forwarding."); |
| |
| /* 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); |
| } |
| } |
| |
| static void |
| check_agent_present(void) |
| { |
| if (options.forward_agent) { |
| /* Clear agent forwarding if we don\'t have an agent. */ |
| int authfd = ssh_get_authentication_socket(); |
| if (authfd < 0) |
| options.forward_agent = 0; |
| else |
| ssh_close_authentication_socket(authfd); |
| } |
| } |
| |
| static int |
| ssh_session(void) |
| { |
| int type; |
| int interactive = 0; |
| int have_tty = 0; |
| struct winsize ws; |
| 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(); |
| 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_cstring(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), NULL); |
| |
| /* Send the packet, and wait for it to leave. */ |
| packet_send(); |
| packet_write_wait(); |
| |
| /* Read response from the server. */ |
| type = packet_read(); |
| 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, *data; |
| /* Get reasonable local authentication information. */ |
| x11_get_proto(&proto, &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(); |
| 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); |
| |
| /* Request authentication agent forwarding if appropriate. */ |
| check_agent_present(); |
| |
| if (options.forward_agent) { |
| debug("Requesting authentication agent forwarding."); |
| auth_request_forwarding(); |
| |
| /* Read response from the server. */ |
| type = packet_read(); |
| packet_check_eom(); |
| if (type != SSH_SMSG_SUCCESS) |
| log("Warning: Remote host denied authentication agent forwarding."); |
| } |
| |
| /* Initiate port forwardings. */ |
| ssh_init_forwarding(); |
| |
| /* 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, (u_char *)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 : SSH_ESCAPECHAR_NONE, 0); |
| } |
| |
| static void |
| client_subsystem_reply(int type, u_int32_t seq, void *ctxt) |
| { |
| int id, len; |
| |
| id = packet_get_int(); |
| len = buffer_len(&command); |
| if (len > 900) |
| len = 900; |
| packet_check_eom(); |
| if (type == SSH2_MSG_CHANNEL_FAILURE) |
| fatal("Request for subsystem '%.*s' failed on channel %d", |
| len, (u_char *)buffer_ptr(&command), id); |
| } |
| |
| /* request pty/x11/agent/tcpfwd/shell for channel */ |
| static void |
| ssh_session2_setup(int id, void *arg) |
| { |
| int len; |
| int interactive = 0; |
| struct termios tio; |
| |
| debug("ssh_session2_setup: id %d", id); |
| |
| 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); |
| tio = get_saved_tio(); |
| tty_make_modes(/*ignored*/ 0, &tio); |
| packet_send(); |
| interactive = 1; |
| /* XXX wait for reply */ |
| } |
| if (options.forward_x11 && |
| getenv("DISPLAY") != NULL) { |
| char *proto, *data; |
| /* Get reasonable local authentication information. */ |
| x11_get_proto(&proto, &data); |
| /* Request forwarding with authentication spoofing. */ |
| debug("Requesting X11 forwarding with authentication spoofing."); |
| x11_request_forwarding_with_spoofing(id, proto, data); |
| interactive = 1; |
| /* XXX wait for reply */ |
| } |
| |
| check_agent_present(); |
| if (options.forward_agent) { |
| debug("Requesting authentication agent forwarding."); |
| channel_request_start(id, "auth-agent-req@openssh.com", 0); |
| packet_send(); |
| } |
| |
| len = buffer_len(&command); |
| if (len > 0) { |
| if (len > 900) |
| len = 900; |
| if (subsystem_flag) { |
| debug("Sending subsystem: %.*s", len, (u_char *)buffer_ptr(&command)); |
| channel_request_start(id, "subsystem", /*want reply*/ 1); |
| /* register callback for reply */ |
| /* XXX we asume that client_loop has already been called */ |
| dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply); |
| dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply); |
| } else { |
| debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); |
| channel_request_start(id, "exec", 0); |
| } |
| packet_put_string(buffer_ptr(&command), buffer_len(&command)); |
| packet_send(); |
| } else { |
| channel_request_start(id, "shell", 0); |
| packet_send(); |
| } |
| |
| packet_set_interactive(interactive); |
| } |
| |
| /* open new channel for a session */ |
| static int |
| ssh_session2_open(void) |
| { |
| Channel *c; |
| int window, packetmax, in, out, err; |
| |
| if (stdin_null_flag) { |
| in = open(_PATH_DEVNULL, O_RDONLY); |
| } else { |
| in = dup(STDIN_FILENO); |
| } |
| out = dup(STDOUT_FILENO); |
| err = dup(STDERR_FILENO); |
| |
| if (in < 0 || out < 0 || err < 0) |
| fatal("dup() in/out/err failed"); |
| |
| /* enable nonblocking unless tty */ |
| if (!isatty(in)) |
| set_nonblock(in); |
| if (!isatty(out)) |
| set_nonblock(out); |
| if (!isatty(err)) |
| set_nonblock(err); |
| |
| window = CHAN_SES_WINDOW_DEFAULT; |
| packetmax = CHAN_SES_PACKET_DEFAULT; |
| if (tty_flag) { |
| window >>= 1; |
| packetmax >>= 1; |
| } |
| c = channel_new( |
| "session", SSH_CHANNEL_OPENING, in, out, err, |
| window, packetmax, CHAN_EXTENDED_WRITE, |
| xstrdup("client-session"), /*nonblock*/0); |
| |
| debug3("ssh_session2_open: channel_new: %d", c->self); |
| |
| channel_send_open(c->self); |
| if (!no_shell_flag) |
| channel_register_confirm(c->self, ssh_session2_setup); |
| |
| return c->self; |
| } |
| |
| static int |
| ssh_session2(void) |
| { |
| int id = -1; |
| |
| /* XXX should be pre-session */ |
| ssh_init_forwarding(); |
| |
| if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) |
| id = ssh_session2_open(); |
| |
| /* If requested, let ssh continue in the background. */ |
| if (fork_after_authentication_flag) |
| if (daemon(1, 1) < 0) |
| fatal("daemon() failed: %.200s", strerror(errno)); |
| |
| return client_loop(tty_flag, tty_flag ? |
| options.escape_char : SSH_ESCAPECHAR_NONE, id); |
| } |
| |
| static void |
| load_public_identity_files(void) |
| { |
| char *filename; |
| int i = 0; |
| Key *public; |
| #ifdef SMARTCARD |
| Key **keys; |
| |
| if (options.smartcard_device != NULL && |
| options.num_identity_files < SSH_MAX_IDENTITY_FILES && |
| (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) { |
| int count = 0; |
| for (i = 0; keys[i] != NULL; i++) { |
| count++; |
| memmove(&options.identity_files[1], &options.identity_files[0], |
| sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1)); |
| memmove(&options.identity_keys[1], &options.identity_keys[0], |
| sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1)); |
| options.num_identity_files++; |
| options.identity_keys[0] = keys[i]; |
| options.identity_files[0] = xstrdup("smartcard key");; |
| } |
| if (options.num_identity_files > SSH_MAX_IDENTITY_FILES) |
| options.num_identity_files = SSH_MAX_IDENTITY_FILES; |
| i = count; |
| xfree(keys); |
| } |
| #endif /* SMARTCARD */ |
| for (; i < options.num_identity_files; i++) { |
| filename = tilde_expand_filename(options.identity_files[i], |
| original_real_uid); |
| public = key_load_public(filename, NULL); |
| debug("identity file %s type %d", filename, |
| public ? public->type : -1); |
| xfree(options.identity_files[i]); |
| options.identity_files[i] = filename; |
| options.identity_keys[i] = public; |
| } |
| } |