| /* $OpenBSD: ssh.c,v 1.405 2014/07/03 06:39:19 djm Exp $ */ |
| /* |
| * 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, 2003 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" |
| |
| #include <sys/types.h> |
| #ifdef HAVE_SYS_STAT_H |
| # include <sys/stat.h> |
| #endif |
| #include <sys/resource.h> |
| #include <sys/ioctl.h> |
| #include <sys/param.h> |
| #include <sys/socket.h> |
| #include <sys/wait.h> |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <netdb.h> |
| #ifdef HAVE_PATHS_H |
| #include <paths.h> |
| #endif |
| #include <pwd.h> |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| |
| #ifdef WITH_OPENSSL |
| #include <openssl/evp.h> |
| #include <openssl/err.h> |
| #endif |
| #include "openbsd-compat/openssl-compat.h" |
| #include "openbsd-compat/sys-queue.h" |
| |
| #include "xmalloc.h" |
| #include "ssh.h" |
| #include "ssh1.h" |
| #include "ssh2.h" |
| #include "canohost.h" |
| #include "compat.h" |
| #include "cipher.h" |
| #include "digest.h" |
| #include "packet.h" |
| #include "buffer.h" |
| #include "channels.h" |
| #include "key.h" |
| #include "authfd.h" |
| #include "authfile.h" |
| #include "pathnames.h" |
| #include "dispatch.h" |
| #include "clientloop.h" |
| #include "log.h" |
| #include "readconf.h" |
| #include "sshconnect.h" |
| #include "misc.h" |
| #include "kex.h" |
| #include "mac.h" |
| #include "sshpty.h" |
| #include "match.h" |
| #include "msg.h" |
| #include "uidswap.h" |
| #include "roaming.h" |
| #include "version.h" |
| |
| #ifdef ENABLE_PKCS11 |
| #include "ssh-pkcs11.h" |
| #endif |
| |
| extern char *__progname; |
| |
| /* Saves a copy of argv for setproctitle emulation */ |
| #ifndef HAVE_SETPROCTITLE |
| static char **saved_av; |
| #endif |
| |
| /* Flag indicating whether debug mode is on. May be set on the command line. */ |
| int debug_flag = 0; |
| |
| /* Flag indicating whether a tty should be requested */ |
| int 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 the current process should be backgrounded and |
| * a new slave launched in the foreground for ControlPersist. |
| */ |
| int need_controlpersist_detach = 0; |
| |
| /* Copies of flags for ControlPersist foreground slave */ |
| int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; |
| |
| /* |
| * Flag indicating that ssh should fork after authentication. This is useful |
| * so that the passphrase can be entered manually, and then ssh goes to the |
| * background. |
| */ |
| int fork_after_authentication_flag = 0; |
| |
| /* forward stdio to remote host and port */ |
| char *stdio_forward_host = NULL; |
| int stdio_forward_port = 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. */ |
| Sensitive sensitive_data; |
| |
| /* Original real UID. */ |
| uid_t original_real_uid; |
| uid_t original_effective_uid; |
| |
| /* command to be executed */ |
| Buffer command; |
| |
| /* Should we execute a command or invoke a subsystem? */ |
| int subsystem_flag = 0; |
| |
| /* # of replies received for global requests */ |
| static int remote_forward_confirms_received = 0; |
| |
| /* mux.c */ |
| extern int muxserver_sock; |
| extern u_int muxclient_command; |
| |
| /* Prints a help message to the user. This function never returns. */ |
| |
| static void |
| usage(void) |
| { |
| fprintf(stderr, |
| "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" |
| " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" |
| " [-F configfile] [-I pkcs11] [-i identity_file]\n" |
| " [-L [bind_address:]port:host:hostport] [-l login_name] [-m mac_spec]\n" |
| " [-O ctl_cmd] [-o option] [-p port]\n" |
| " [-Q cipher | cipher-auth | mac | kex | key]\n" |
| " [-R [bind_address:]port:host:hostport] [-S ctl_path] [-W host:port]\n" |
| " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" |
| ); |
| exit(255); |
| } |
| |
| static int ssh_session(void); |
| static int ssh_session2(void); |
| static void load_public_identity_files(void); |
| static void main_sigchld_handler(int); |
| |
| /* from muxclient.c */ |
| void muxclient(const char *); |
| void muxserver_listen(void); |
| |
| /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ |
| static void |
| tilde_expand_paths(char **paths, u_int num_paths) |
| { |
| u_int i; |
| char *cp; |
| |
| for (i = 0; i < num_paths; i++) { |
| cp = tilde_expand_filename(paths[i], original_real_uid); |
| free(paths[i]); |
| paths[i] = cp; |
| } |
| } |
| |
| /* |
| * Attempt to resolve a host name / port to a set of addresses and |
| * optionally return any CNAMEs encountered along the way. |
| * Returns NULL on failure. |
| * NB. this function must operate with a options having undefined members. |
| */ |
| static struct addrinfo * |
| resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) |
| { |
| char strport[NI_MAXSERV]; |
| struct addrinfo hints, *res; |
| int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; |
| |
| if (port <= 0) |
| port = default_ssh_port(); |
| |
| snprintf(strport, sizeof strport, "%u", port); |
| memset(&hints, 0, sizeof(hints)); |
| hints.ai_family = options.address_family == -1 ? |
| AF_UNSPEC : options.address_family; |
| hints.ai_socktype = SOCK_STREAM; |
| if (cname != NULL) |
| hints.ai_flags = AI_CANONNAME; |
| if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { |
| if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) |
| loglevel = SYSLOG_LEVEL_ERROR; |
| do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", |
| __progname, name, ssh_gai_strerror(gaierr)); |
| return NULL; |
| } |
| if (cname != NULL && res->ai_canonname != NULL) { |
| if (strlcpy(cname, res->ai_canonname, clen) >= clen) { |
| error("%s: host \"%s\" cname \"%s\" too long (max %lu)", |
| __func__, name, res->ai_canonname, (u_long)clen); |
| if (clen > 0) |
| *cname = '\0'; |
| } |
| } |
| return res; |
| } |
| |
| /* |
| * Check whether the cname is a permitted replacement for the hostname |
| * and perform the replacement if it is. |
| * NB. this function must operate with a options having undefined members. |
| */ |
| static int |
| check_follow_cname(char **namep, const char *cname) |
| { |
| int i; |
| struct allowed_cname *rule; |
| |
| if (*cname == '\0' || options.num_permitted_cnames == 0 || |
| strcmp(*namep, cname) == 0) |
| return 0; |
| if (options.canonicalize_hostname == SSH_CANONICALISE_NO) |
| return 0; |
| /* |
| * Don't attempt to canonicalize names that will be interpreted by |
| * a proxy unless the user specifically requests so. |
| */ |
| if (!option_clear_or_none(options.proxy_command) && |
| options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) |
| return 0; |
| debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); |
| for (i = 0; i < options.num_permitted_cnames; i++) { |
| rule = options.permitted_cnames + i; |
| if (match_pattern_list(*namep, rule->source_list, |
| strlen(rule->source_list), 1) != 1 || |
| match_pattern_list(cname, rule->target_list, |
| strlen(rule->target_list), 1) != 1) |
| continue; |
| verbose("Canonicalized DNS aliased hostname " |
| "\"%s\" => \"%s\"", *namep, cname); |
| free(*namep); |
| *namep = xstrdup(cname); |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* |
| * Attempt to resolve the supplied hostname after applying the user's |
| * canonicalization rules. Returns the address list for the host or NULL |
| * if no name was found after canonicalization. |
| * NB. this function must operate with a options having undefined members. |
| */ |
| static struct addrinfo * |
| resolve_canonicalize(char **hostp, int port) |
| { |
| int i, ndots; |
| char *cp, *fullhost, cname_target[NI_MAXHOST]; |
| struct addrinfo *addrs; |
| |
| if (options.canonicalize_hostname == SSH_CANONICALISE_NO) |
| return NULL; |
| |
| /* |
| * Don't attempt to canonicalize names that will be interpreted by |
| * a proxy unless the user specifically requests so. |
| */ |
| if (!option_clear_or_none(options.proxy_command) && |
| options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) |
| return NULL; |
| |
| /* Don't apply canonicalization to sufficiently-qualified hostnames */ |
| ndots = 0; |
| for (cp = *hostp; *cp != '\0'; cp++) { |
| if (*cp == '.') |
| ndots++; |
| } |
| if (ndots > options.canonicalize_max_dots) { |
| debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", |
| __func__, *hostp, options.canonicalize_max_dots); |
| return NULL; |
| } |
| /* Attempt each supplied suffix */ |
| for (i = 0; i < options.num_canonical_domains; i++) { |
| *cname_target = '\0'; |
| xasprintf(&fullhost, "%s.%s.", *hostp, |
| options.canonical_domains[i]); |
| debug3("%s: attempting \"%s\" => \"%s\"", __func__, |
| *hostp, fullhost); |
| if ((addrs = resolve_host(fullhost, port, 0, |
| cname_target, sizeof(cname_target))) == NULL) { |
| free(fullhost); |
| continue; |
| } |
| /* Remove trailing '.' */ |
| fullhost[strlen(fullhost) - 1] = '\0'; |
| /* Follow CNAME if requested */ |
| if (!check_follow_cname(&fullhost, cname_target)) { |
| debug("Canonicalized hostname \"%s\" => \"%s\"", |
| *hostp, fullhost); |
| } |
| free(*hostp); |
| *hostp = fullhost; |
| return addrs; |
| } |
| if (!options.canonicalize_fallback_local) |
| fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); |
| debug2("%s: host %s not found in any suffix", __func__, *hostp); |
| return NULL; |
| } |
| |
| /* |
| * Read per-user configuration file. Ignore the system wide config |
| * file if the user specifies a config file on the command line. |
| */ |
| static void |
| process_config_files(struct passwd *pw) |
| { |
| char buf[MAXPATHLEN]; |
| int r; |
| |
| if (config != NULL) { |
| if (strcasecmp(config, "none") != 0 && |
| !read_config_file(config, pw, host, &options, |
| SSHCONF_USERCONF)) |
| fatal("Can't open user config file %.100s: " |
| "%.100s", config, strerror(errno)); |
| } else { |
| r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, |
| _PATH_SSH_USER_CONFFILE); |
| if (r > 0 && (size_t)r < sizeof(buf)) |
| (void)read_config_file(buf, pw, host, &options, |
| SSHCONF_CHECKPERM|SSHCONF_USERCONF); |
| |
| /* Read systemwide configuration file after user config. */ |
| (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, host, |
| &options, 0); |
| } |
| } |
| |
| /* |
| * Main program for the ssh client. |
| */ |
| int |
| main(int ac, char **av) |
| { |
| int i, r, opt, exit_status, use_syslog; |
| char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg, *logfile; |
| char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; |
| char cname[NI_MAXHOST]; |
| struct stat st; |
| struct passwd *pw; |
| int timeout_ms; |
| extern int optind, optreset; |
| extern char *optarg; |
| Forward fwd; |
| struct addrinfo *addrs = NULL; |
| struct ssh_digest_ctx *md; |
| u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; |
| char *conn_hash_hex; |
| |
| /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ |
| sanitise_stdfd(); |
| |
| __progname = ssh_get_progname(av[0]); |
| |
| #ifndef HAVE_SETPROCTITLE |
| /* Prepare for later setproctitle emulation */ |
| /* Save argv so it isn't clobbered by setproctitle() emulation */ |
| saved_av = xcalloc(ac + 1, sizeof(*saved_av)); |
| for (i = 0; i < ac; i++) |
| saved_av[i] = xstrdup(av[i]); |
| saved_av[i] = NULL; |
| compat_init_setproctitle(ac, av); |
| av = saved_av; |
| #endif |
| |
| /* |
| * Discard other fds that are hanging around. These can cause problem |
| * with backgrounded ssh processes started by ControlPersist. |
| */ |
| closefrom(STDERR_FILENO + 1); |
| |
| /* |
| * 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(); |
| |
| /* |
| * 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). |
| */ |
| PRIV_END; |
| |
| #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) { |
| logit("No user exists for uid %lu", (u_long)original_real_uid); |
| exit(255); |
| } |
| /* Take a copy of the returned structure. */ |
| pw = pwcopy(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; |
| use_syslog = 0; |
| logfile = NULL; |
| argv0 = av[0]; |
| |
| again: |
| while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" |
| "ACD:E:F:I:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { |
| switch (opt) { |
| case '1': |
| options.protocol = SSH_PROTO_1; |
| break; |
| case '2': |
| options.protocol = SSH_PROTO_2; |
| break; |
| case '4': |
| options.address_family = AF_INET; |
| break; |
| case '6': |
| options.address_family = 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 'y': |
| use_syslog = 1; |
| break; |
| case 'E': |
| logfile = xstrdup(optarg); |
| break; |
| case 'Y': |
| options.forward_x11 = 1; |
| options.forward_x11_trusted = 1; |
| break; |
| case 'g': |
| options.gateway_ports = 1; |
| break; |
| case 'O': |
| if (stdio_forward_host != NULL) |
| fatal("Cannot specify multiplexing " |
| "command with -W"); |
| else if (muxclient_command != 0) |
| fatal("Multiplexing command already specified"); |
| if (strcmp(optarg, "check") == 0) |
| muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; |
| else if (strcmp(optarg, "forward") == 0) |
| muxclient_command = SSHMUX_COMMAND_FORWARD; |
| else if (strcmp(optarg, "exit") == 0) |
| muxclient_command = SSHMUX_COMMAND_TERMINATE; |
| else if (strcmp(optarg, "stop") == 0) |
| muxclient_command = SSHMUX_COMMAND_STOP; |
| else if (strcmp(optarg, "cancel") == 0) |
| muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; |
| else |
| fatal("Invalid multiplex command."); |
| break; |
| case 'P': /* deprecated */ |
| options.use_privileged_port = 0; |
| break; |
| case 'Q': |
| cp = NULL; |
| if (strcmp(optarg, "cipher") == 0) |
| cp = cipher_alg_list('\n', 0); |
| else if (strcmp(optarg, "cipher-auth") == 0) |
| cp = cipher_alg_list('\n', 1); |
| else if (strcmp(optarg, "mac") == 0) |
| cp = mac_alg_list('\n'); |
| else if (strcmp(optarg, "kex") == 0) |
| cp = kex_alg_list('\n'); |
| else if (strcmp(optarg, "key") == 0) |
| cp = key_alg_list(0, 0); |
| else if (strcmp(optarg, "key-cert") == 0) |
| cp = key_alg_list(1, 0); |
| else if (strcmp(optarg, "key-plain") == 0) |
| cp = key_alg_list(0, 1); |
| if (cp == NULL) |
| fatal("Unsupported query \"%s\"", optarg); |
| printf("%s\n", cp); |
| free(cp); |
| exit(0); |
| break; |
| case 'a': |
| options.forward_agent = 0; |
| break; |
| case 'A': |
| options.forward_agent = 1; |
| break; |
| case 'k': |
| options.gss_deleg_creds = 0; |
| break; |
| case 'K': |
| options.gss_authentication = 1; |
| options.gss_deleg_creds = 1; |
| break; |
| case 'i': |
| if (stat(optarg, &st) < 0) { |
| fprintf(stderr, "Warning: Identity file %s " |
| "not accessible: %s.\n", optarg, |
| strerror(errno)); |
| break; |
| } |
| add_identity_file(&options, NULL, optarg, 1); |
| break; |
| case 'I': |
| #ifdef ENABLE_PKCS11 |
| options.pkcs11_provider = xstrdup(optarg); |
| #else |
| fprintf(stderr, "no support for PKCS#11.\n"); |
| #endif |
| break; |
| case 't': |
| if (options.request_tty == REQUEST_TTY_YES) |
| options.request_tty = REQUEST_TTY_FORCE; |
| else |
| options.request_tty = REQUEST_TTY_YES; |
| break; |
| case 'v': |
| if (debug_flag == 0) { |
| debug_flag = 1; |
| options.log_level = SYSLOG_LEVEL_DEBUG1; |
| } else { |
| if (options.log_level < SYSLOG_LEVEL_DEBUG3) |
| options.log_level++; |
| } |
| break; |
| case 'V': |
| fprintf(stderr, "%s, %s\n", |
| SSH_RELEASE, |
| #ifdef WITH_OPENSSL |
| SSLeay_version(SSLEAY_VERSION) |
| #else |
| "without OpenSSL" |
| #endif |
| ); |
| if (opt == 'V') |
| exit(0); |
| break; |
| case 'w': |
| if (options.tun_open == -1) |
| options.tun_open = SSH_TUNMODE_DEFAULT; |
| options.tun_local = a2tun(optarg, &options.tun_remote); |
| if (options.tun_local == SSH_TUNID_ERR) { |
| fprintf(stderr, |
| "Bad tun device '%s'\n", optarg); |
| exit(255); |
| } |
| break; |
| case 'W': |
| if (stdio_forward_host != NULL) |
| fatal("stdio forward already specified"); |
| if (muxclient_command != 0) |
| fatal("Cannot specify stdio forward with -O"); |
| if (parse_forward(&fwd, optarg, 1, 0)) { |
| stdio_forward_host = fwd.listen_host; |
| stdio_forward_port = fwd.listen_port; |
| free(fwd.connect_host); |
| } else { |
| fprintf(stderr, |
| "Bad stdio forwarding specification '%s'\n", |
| optarg); |
| exit(255); |
| } |
| options.request_tty = REQUEST_TTY_NO; |
| no_shell_flag = 1; |
| options.clear_forwardings = 1; |
| options.exit_on_forward_failure = 1; |
| 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(255); |
| } |
| break; |
| case 'c': |
| if (ciphers_valid(optarg)) { |
| /* SSH2 only */ |
| options.ciphers = xstrdup(optarg); |
| options.cipher = SSH_CIPHER_INVALID; |
| } else { |
| /* SSH1 only */ |
| options.cipher = cipher_number(optarg); |
| if (options.cipher == -1) { |
| fprintf(stderr, |
| "Unknown cipher type '%s'\n", |
| optarg); |
| exit(255); |
| } |
| 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(255); |
| } |
| break; |
| case 'M': |
| if (options.control_master == SSHCTL_MASTER_YES) |
| options.control_master = SSHCTL_MASTER_ASK; |
| else |
| options.control_master = SSHCTL_MASTER_YES; |
| break; |
| case 'p': |
| options.port = a2port(optarg); |
| if (options.port <= 0) { |
| fprintf(stderr, "Bad port '%s'\n", optarg); |
| exit(255); |
| } |
| break; |
| case 'l': |
| options.user = optarg; |
| break; |
| |
| case 'L': |
| if (parse_forward(&fwd, optarg, 0, 0)) |
| add_local_forward(&options, &fwd); |
| else { |
| fprintf(stderr, |
| "Bad local forwarding specification '%s'\n", |
| optarg); |
| exit(255); |
| } |
| break; |
| |
| case 'R': |
| if (parse_forward(&fwd, optarg, 0, 1)) { |
| add_remote_forward(&options, &fwd); |
| } else { |
| fprintf(stderr, |
| "Bad remote forwarding specification " |
| "'%s'\n", optarg); |
| exit(255); |
| } |
| break; |
| |
| case 'D': |
| if (parse_forward(&fwd, optarg, 1, 0)) { |
| add_local_forward(&options, &fwd); |
| } else { |
| fprintf(stderr, |
| "Bad dynamic forwarding specification " |
| "'%s'\n", optarg); |
| exit(255); |
| } |
| break; |
| |
| case 'C': |
| options.compression = 1; |
| break; |
| case 'N': |
| no_shell_flag = 1; |
| options.request_tty = REQUEST_TTY_NO; |
| break; |
| case 'T': |
| options.request_tty = REQUEST_TTY_NO; |
| break; |
| case 'o': |
| line = xstrdup(optarg); |
| if (process_config_line(&options, pw, host ? host : "", |
| line, "command-line", 0, NULL, SSHCONF_USERCONF) |
| != 0) |
| exit(255); |
| free(line); |
| break; |
| case 's': |
| subsystem_flag = 1; |
| break; |
| case 'S': |
| if (options.control_path != NULL) |
| free(options.control_path); |
| options.control_path = xstrdup(optarg); |
| break; |
| case 'b': |
| options.bind_address = optarg; |
| break; |
| case 'F': |
| config = optarg; |
| break; |
| default: |
| usage(); |
| } |
| } |
| |
| ac -= optind; |
| av += optind; |
| |
| if (ac > 0 && !host) { |
| if (strrchr(*av, '@')) { |
| p = xstrdup(*av); |
| cp = strrchr(p, '@'); |
| if (cp == NULL || cp == p) |
| usage(); |
| options.user = p; |
| *cp = '\0'; |
| host = xstrdup(++cp); |
| } else |
| host = xstrdup(*av); |
| if (ac > 1) { |
| optind = optreset = 1; |
| goto again; |
| } |
| ac--, av++; |
| } |
| |
| /* Check that we got a host name. */ |
| if (!host) |
| usage(); |
| |
| host_arg = xstrdup(host); |
| |
| #ifdef WITH_OPENSSL |
| OpenSSL_add_all_algorithms(); |
| ERR_load_crypto_strings(); |
| #endif |
| |
| /* 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. */ |
| 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."); |
| |
| /* |
| * Initialize "log" output. Since we are the client all output |
| * goes to stderr unless otherwise specified by -y or -E. |
| */ |
| if (use_syslog && logfile != NULL) |
| fatal("Can't specify both -y and -E"); |
| if (logfile != NULL) { |
| log_redirect_stderr_to(logfile); |
| free(logfile); |
| } |
| log_init(argv0, |
| options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, |
| SYSLOG_FACILITY_USER, !use_syslog); |
| |
| if (debug_flag) |
| logit("%s, %s", SSH_RELEASE, |
| #ifdef WITH_OPENSSL |
| SSLeay_version(SSLEAY_VERSION) |
| #else |
| "without OpenSSL" |
| #endif |
| ); |
| |
| /* Parse the configuration files */ |
| process_config_files(pw); |
| |
| /* Hostname canonicalisation needs a few options filled. */ |
| fill_default_options_for_canonicalization(&options); |
| |
| /* If the user has replaced the hostname then take it into use now */ |
| if (options.hostname != NULL) { |
| /* NB. Please keep in sync with readconf.c:match_cfg_line() */ |
| cp = percent_expand(options.hostname, |
| "h", host, (char *)NULL); |
| free(host); |
| host = cp; |
| } |
| |
| /* If canonicalization requested then try to apply it */ |
| lowercase(host); |
| if (options.canonicalize_hostname != SSH_CANONICALISE_NO) |
| addrs = resolve_canonicalize(&host, options.port); |
| |
| /* |
| * If CanonicalizePermittedCNAMEs have been specified but |
| * other canonicalization did not happen (by not being requested |
| * or by failing with fallback) then the hostname may still be changed |
| * as a result of CNAME following. |
| * |
| * Try to resolve the bare hostname name using the system resolver's |
| * usual search rules and then apply the CNAME follow rules. |
| * |
| * Skip the lookup if a ProxyCommand is being used unless the user |
| * has specifically requested canonicalisation for this case via |
| * CanonicalizeHostname=always |
| */ |
| if (addrs == NULL && options.num_permitted_cnames != 0 && |
| (option_clear_or_none(options.proxy_command) || |
| options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { |
| if ((addrs = resolve_host(host, options.port, |
| option_clear_or_none(options.proxy_command), |
| cname, sizeof(cname))) == NULL) { |
| /* Don't fatal proxied host names not in the DNS */ |
| if (option_clear_or_none(options.proxy_command)) |
| cleanup_exit(255); /* logged in resolve_host */ |
| } else |
| check_follow_cname(&host, cname); |
| } |
| |
| /* |
| * If the target hostname has changed as a result of canonicalisation |
| * then re-parse the configuration files as new stanzas may match. |
| */ |
| if (strcasecmp(host_arg, host) != 0) { |
| debug("Hostname has changed; re-reading configuration"); |
| process_config_files(pw); |
| } |
| |
| /* Fill configuration defaults. */ |
| fill_default_options(&options); |
| |
| if (options.port == 0) |
| options.port = default_ssh_port(); |
| channel_set_af(options.address_family); |
| |
| /* Tidy and check options */ |
| if (options.host_key_alias != NULL) |
| lowercase(options.host_key_alias); |
| if (options.proxy_command != NULL && |
| strcmp(options.proxy_command, "-") == 0 && |
| options.proxy_use_fdpass) |
| fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); |
| #ifndef HAVE_CYGWIN |
| if (original_effective_uid != 0) |
| options.use_privileged_port = 0; |
| #endif |
| |
| /* reinit */ |
| log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); |
| |
| if (options.request_tty == REQUEST_TTY_YES || |
| options.request_tty == REQUEST_TTY_FORCE) |
| tty_flag = 1; |
| |
| /* Allocate a tty by default if no command specified. */ |
| if (buffer_len(&command) == 0) |
| tty_flag = options.request_tty != REQUEST_TTY_NO; |
| |
| /* Force no tty */ |
| if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) |
| tty_flag = 0; |
| /* Do not allocate a tty if stdin is not a tty. */ |
| if ((!isatty(fileno(stdin)) || stdin_null_flag) && |
| options.request_tty != REQUEST_TTY_FORCE) { |
| if (tty_flag) |
| logit("Pseudo-terminal will not be allocated because " |
| "stdin is not a terminal."); |
| tty_flag = 0; |
| } |
| |
| seed_rng(); |
| |
| if (options.user == NULL) |
| options.user = xstrdup(pw->pw_name); |
| |
| if (gethostname(thishost, sizeof(thishost)) == -1) |
| fatal("gethostname: %s", strerror(errno)); |
| strlcpy(shorthost, thishost, sizeof(shorthost)); |
| shorthost[strcspn(thishost, ".")] = '\0'; |
| snprintf(portstr, sizeof(portstr), "%d", options.port); |
| |
| if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || |
| ssh_digest_update(md, thishost, strlen(thishost)) < 0 || |
| ssh_digest_update(md, host, strlen(host)) < 0 || |
| ssh_digest_update(md, portstr, strlen(portstr)) < 0 || |
| ssh_digest_update(md, options.user, strlen(options.user)) < 0 || |
| ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) |
| fatal("%s: mux digest failed", __func__); |
| ssh_digest_free(md); |
| conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); |
| |
| if (options.local_command != NULL) { |
| debug3("expanding LocalCommand: %s", options.local_command); |
| cp = options.local_command; |
| options.local_command = percent_expand(cp, |
| "C", conn_hash_hex, |
| "L", shorthost, |
| "d", pw->pw_dir, |
| "h", host, |
| "l", thishost, |
| "n", host_arg, |
| "p", portstr, |
| "r", options.user, |
| "u", pw->pw_name, |
| (char *)NULL); |
| debug3("expanded LocalCommand: %s", options.local_command); |
| free(cp); |
| } |
| |
| if (options.control_path != NULL) { |
| cp = tilde_expand_filename(options.control_path, |
| original_real_uid); |
| free(options.control_path); |
| options.control_path = percent_expand(cp, |
| "C", conn_hash_hex, |
| "L", shorthost, |
| "h", host, |
| "l", thishost, |
| "n", host_arg, |
| "p", portstr, |
| "r", options.user, |
| "u", pw->pw_name, |
| (char *)NULL); |
| free(cp); |
| } |
| free(conn_hash_hex); |
| |
| if (muxclient_command != 0 && options.control_path == NULL) |
| fatal("No ControlPath specified for \"-O\" command"); |
| if (options.control_path != NULL) |
| muxclient(options.control_path); |
| |
| /* |
| * If hostname canonicalisation was not enabled, then we may not |
| * have yet resolved the hostname. Do so now. |
| */ |
| if (addrs == NULL && options.proxy_command == NULL) { |
| if ((addrs = resolve_host(host, options.port, 1, |
| cname, sizeof(cname))) == NULL) |
| cleanup_exit(255); /* resolve_host logs the error */ |
| } |
| |
| timeout_ms = options.connection_timeout * 1000; |
| |
| /* Open a connection to the remote host. */ |
| if (ssh_connect(host, addrs, &hostaddr, options.port, |
| options.address_family, options.connection_attempts, |
| &timeout_ms, options.tcp_keep_alive, |
| options.use_privileged_port) != 0) |
| exit(255); |
| |
| if (addrs != NULL) |
| freeaddrinfo(addrs); |
| |
| packet_set_timeout(options.server_alive_interval, |
| options.server_alive_count_max); |
| |
| if (timeout_ms > 0) |
| debug3("timeout: %d ms remain after connect", timeout_ms); |
| |
| /* |
| * 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 we cannot access the private keys, load the public keys |
| * instead and try to execute the ssh-keysign helper instead. |
| */ |
| sensitive_data.nkeys = 0; |
| sensitive_data.keys = NULL; |
| sensitive_data.external_keysign = 0; |
| if (options.rhosts_rsa_authentication || |
| options.hostbased_authentication) { |
| sensitive_data.nkeys = 9; |
| sensitive_data.keys = xcalloc(sensitive_data.nkeys, |
| sizeof(Key)); |
| for (i = 0; i < sensitive_data.nkeys; i++) |
| sensitive_data.keys[i] = NULL; |
| |
| PRIV_START; |
| sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, |
| _PATH_HOST_KEY_FILE, "", NULL, NULL); |
| sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, |
| _PATH_HOST_DSA_KEY_FILE, "", NULL); |
| #ifdef OPENSSL_HAS_ECC |
| sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, |
| _PATH_HOST_ECDSA_KEY_FILE, "", NULL); |
| #endif |
| sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, |
| _PATH_HOST_RSA_KEY_FILE, "", NULL); |
| sensitive_data.keys[4] = key_load_private_cert(KEY_ED25519, |
| _PATH_HOST_ED25519_KEY_FILE, "", NULL); |
| sensitive_data.keys[5] = key_load_private_type(KEY_DSA, |
| _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); |
| #ifdef OPENSSL_HAS_ECC |
| sensitive_data.keys[6] = key_load_private_type(KEY_ECDSA, |
| _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); |
| #endif |
| sensitive_data.keys[7] = key_load_private_type(KEY_RSA, |
| _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); |
| sensitive_data.keys[8] = key_load_private_type(KEY_ED25519, |
| _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); |
| PRIV_END; |
| |
| if (options.hostbased_authentication == 1 && |
| sensitive_data.keys[0] == NULL && |
| sensitive_data.keys[5] == NULL && |
| sensitive_data.keys[6] == NULL && |
| sensitive_data.keys[7] == NULL && |
| sensitive_data.keys[8] == NULL) { |
| sensitive_data.keys[1] = key_load_cert( |
| _PATH_HOST_DSA_KEY_FILE); |
| #ifdef OPENSSL_HAS_ECC |
| sensitive_data.keys[2] = key_load_cert( |
| _PATH_HOST_ECDSA_KEY_FILE); |
| #endif |
| sensitive_data.keys[3] = key_load_cert( |
| _PATH_HOST_RSA_KEY_FILE); |
| sensitive_data.keys[4] = key_load_cert( |
| _PATH_HOST_ED25519_KEY_FILE); |
| sensitive_data.keys[5] = key_load_public( |
| _PATH_HOST_DSA_KEY_FILE, NULL); |
| #ifdef OPENSSL_HAS_ECC |
| sensitive_data.keys[6] = key_load_public( |
| _PATH_HOST_ECDSA_KEY_FILE, NULL); |
| #endif |
| sensitive_data.keys[7] = key_load_public( |
| _PATH_HOST_RSA_KEY_FILE, NULL); |
| sensitive_data.keys[8] = key_load_public( |
| _PATH_HOST_ED25519_KEY_FILE, NULL); |
| sensitive_data.external_keysign = 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. |
| */ |
| if (original_effective_uid == 0) { |
| PRIV_START; |
| permanently_set_uid(pw); |
| } |
| |
| /* |
| * Now that we are back to our own permissions, create ~/.ssh |
| * directory if it doesn't already exist. |
| */ |
| if (config == NULL) { |
| r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, |
| strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); |
| if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { |
| #ifdef WITH_SELINUX |
| ssh_selinux_setfscreatecon(buf); |
| #endif |
| if (mkdir(buf, 0700) < 0) |
| error("Could not create directory '%.200s'.", |
| buf); |
| #ifdef WITH_SELINUX |
| ssh_selinux_setfscreatecon(NULL); |
| #endif |
| } |
| } |
| /* load options.identity_files */ |
| load_public_identity_files(); |
| |
| /* Expand ~ in known host file names. */ |
| tilde_expand_paths(options.system_hostfiles, |
| options.num_system_hostfiles); |
| tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); |
| |
| signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ |
| signal(SIGCHLD, main_sigchld_handler); |
| |
| /* Log into the remote system. Never returns if the login fails. */ |
| ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, |
| options.port, pw, timeout_ms); |
| |
| if (packet_connection_is_on_socket()) { |
| verbose("Authenticated to %s ([%s]:%d).", host, |
| get_remote_ipaddr(), get_remote_port()); |
| } else { |
| verbose("Authenticated to %s (via proxy).", host); |
| } |
| |
| /* 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; |
| } |
| } |
| free(sensitive_data.keys); |
| } |
| for (i = 0; i < options.num_identity_files; i++) { |
| free(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(); |
| |
| if (options.control_path != NULL && muxserver_sock != -1) |
| unlink(options.control_path); |
| |
| /* Kill ProxyCommand if it is running. */ |
| ssh_kill_proxy_command(); |
| |
| return exit_status; |
| } |
| |
| static void |
| control_persist_detach(void) |
| { |
| pid_t pid; |
| int devnull; |
| |
| debug("%s: backgrounding master process", __func__); |
| |
| /* |
| * master (current process) into the background, and make the |
| * foreground process a client of the backgrounded master. |
| */ |
| switch ((pid = fork())) { |
| case -1: |
| fatal("%s: fork: %s", __func__, strerror(errno)); |
| case 0: |
| /* Child: master process continues mainloop */ |
| break; |
| default: |
| /* Parent: set up mux slave to connect to backgrounded master */ |
| debug2("%s: background process is %ld", __func__, (long)pid); |
| stdin_null_flag = ostdin_null_flag; |
| options.request_tty = orequest_tty; |
| tty_flag = otty_flag; |
| close(muxserver_sock); |
| muxserver_sock = -1; |
| options.control_master = SSHCTL_MASTER_NO; |
| muxclient(options.control_path); |
| /* muxclient() doesn't return on success. */ |
| fatal("Failed to connect to new control master"); |
| } |
| if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { |
| error("%s: open(\"/dev/null\"): %s", __func__, |
| strerror(errno)); |
| } else { |
| if (dup2(devnull, STDIN_FILENO) == -1 || |
| dup2(devnull, STDOUT_FILENO) == -1) |
| error("%s: dup2: %s", __func__, strerror(errno)); |
| if (devnull > STDERR_FILENO) |
| close(devnull); |
| } |
| daemon(1, 1); |
| setproctitle("%s [mux]", options.control_path); |
| } |
| |
| /* Do fork() after authentication. Used by "ssh -f" */ |
| static void |
| fork_postauth(void) |
| { |
| if (need_controlpersist_detach) |
| control_persist_detach(); |
| debug("forking to background"); |
| fork_after_authentication_flag = 0; |
| if (daemon(1, 1) < 0) |
| fatal("daemon() failed: %.200s", strerror(errno)); |
| } |
| |
| /* Callback for remote forward global requests */ |
| static void |
| ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) |
| { |
| Forward *rfwd = (Forward *)ctxt; |
| |
| /* XXX verbose() on failure? */ |
| debug("remote forward %s for: listen %s%s%d, connect %s:%d", |
| type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", |
| rfwd->listen_host == NULL ? "" : rfwd->listen_host, |
| rfwd->listen_host == NULL ? "" : ":", |
| rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); |
| if (rfwd->listen_port == 0) { |
| if (type == SSH2_MSG_REQUEST_SUCCESS) { |
| rfwd->allocated_port = packet_get_int(); |
| logit("Allocated port %u for remote forward to %s:%d", |
| rfwd->allocated_port, |
| rfwd->connect_host, rfwd->connect_port); |
| channel_update_permitted_opens(rfwd->handle, |
| rfwd->allocated_port); |
| } else { |
| channel_update_permitted_opens(rfwd->handle, -1); |
| } |
| } |
| |
| if (type == SSH2_MSG_REQUEST_FAILURE) { |
| if (options.exit_on_forward_failure) |
| fatal("Error: remote port forwarding failed for " |
| "listen port %d", rfwd->listen_port); |
| else |
| logit("Warning: remote port forwarding failed for " |
| "listen port %d", rfwd->listen_port); |
| } |
| if (++remote_forward_confirms_received == options.num_remote_forwards) { |
| debug("All remote forwarding requests processed"); |
| if (fork_after_authentication_flag) |
| fork_postauth(); |
| } |
| } |
| |
| static void |
| client_cleanup_stdio_fwd(int id, void *arg) |
| { |
| debug("stdio forwarding: done"); |
| cleanup_exit(0); |
| } |
| |
| static void |
| ssh_init_stdio_forwarding(void) |
| { |
| Channel *c; |
| int in, out; |
| |
| if (stdio_forward_host == NULL) |
| return; |
| if (!compat20) |
| fatal("stdio forwarding require Protocol 2"); |
| |
| debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); |
| |
| if ((in = dup(STDIN_FILENO)) < 0 || |
| (out = dup(STDOUT_FILENO)) < 0) |
| fatal("channel_connect_stdio_fwd: dup() in/out failed"); |
| if ((c = channel_connect_stdio_fwd(stdio_forward_host, |
| stdio_forward_port, in, out)) == NULL) |
| fatal("%s: channel_connect_stdio_fwd failed", __func__); |
| channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); |
| } |
| |
| 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("Local connections to %.200s:%d forwarded to remote " |
| "address %.200s:%d", |
| (options.local_forwards[i].listen_host == NULL) ? |
| (options.gateway_ports ? "*" : "LOCALHOST") : |
| options.local_forwards[i].listen_host, |
| options.local_forwards[i].listen_port, |
| options.local_forwards[i].connect_host, |
| options.local_forwards[i].connect_port); |
| success += channel_setup_local_fwd_listener( |
| options.local_forwards[i].listen_host, |
| options.local_forwards[i].listen_port, |
| options.local_forwards[i].connect_host, |
| options.local_forwards[i].connect_port, |
| options.gateway_ports); |
| } |
| if (i > 0 && success != i && options.exit_on_forward_failure) |
| fatal("Could not request local forwarding."); |
| 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("Remote connections from %.200s:%d forwarded to " |
| "local address %.200s:%d", |
| (options.remote_forwards[i].listen_host == NULL) ? |
| "LOCALHOST" : options.remote_forwards[i].listen_host, |
| options.remote_forwards[i].listen_port, |
| options.remote_forwards[i].connect_host, |
| options.remote_forwards[i].connect_port); |
| options.remote_forwards[i].handle = |
| channel_request_remote_forwarding( |
| options.remote_forwards[i].listen_host, |
| options.remote_forwards[i].listen_port, |
| options.remote_forwards[i].connect_host, |
| options.remote_forwards[i].connect_port); |
| if (options.remote_forwards[i].handle < 0) { |
| if (options.exit_on_forward_failure) |
| fatal("Could not request remote forwarding."); |
| else |
| logit("Warning: Could not request remote " |
| "forwarding."); |
| } else { |
| client_register_global_confirm(ssh_confirm_remote_forward, |
| &options.remote_forwards[i]); |
| } |
| } |
| |
| /* Initiate tunnel forwarding. */ |
| if (options.tun_open != SSH_TUNMODE_NO) { |
| if (client_request_tun_fwd(options.tun_open, |
| options.tun_local, options.tun_remote) == -1) { |
| if (options.exit_on_forward_failure) |
| fatal("Could not request tunnel forwarding."); |
| else |
| error("Could not request tunnel forwarding."); |
| } |
| } |
| } |
| |
| static void |
| check_agent_present(void) |
| { |
| if (options.forward_agent) { |
| /* Clear agent forwarding if we don't have an agent. */ |
| if (!ssh_agent_present()) |
| options.forward_agent = 0; |
| } |
| } |
| |
| static int |
| ssh_session(void) |
| { |
| int type; |
| int interactive = 0; |
| int have_tty = 0; |
| struct winsize ws; |
| char *cp; |
| const char *display; |
| |
| /* 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) |
| logit("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((u_int)ws.ws_row); |
| packet_put_int((u_int)ws.ws_col); |
| packet_put_int((u_int)ws.ws_xpixel); |
| packet_put_int((u_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) |
| logit("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. */ |
| display = getenv("DISPLAY"); |
| if (options.forward_x11 && display != NULL) { |
| char *proto, *data; |
| /* Get reasonable local authentication information. */ |
| client_x11_get_proto(display, options.xauth_location, |
| options.forward_x11_trusted, |
| options.forward_x11_timeout, |
| &proto, &data); |
| /* Request forwarding with authentication spoofing. */ |
| debug("Requesting X11 forwarding with authentication " |
| "spoofing."); |
| x11_request_forwarding_with_spoofing(0, display, proto, |
| data, 0); |
| /* Read response from the server. */ |
| type = packet_read(); |
| if (type == SSH_SMSG_SUCCESS) { |
| interactive = 1; |
| } else if (type == SSH_SMSG_FAILURE) { |
| logit("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.ip_qos_interactive, options.ip_qos_bulk); |
| |
| /* 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) |
| logit("Warning: Remote host denied authentication agent forwarding."); |
| } |
| |
| /* Initiate port forwardings. */ |
| ssh_init_stdio_forwarding(); |
| ssh_init_forwarding(); |
| |
| /* Execute a local command */ |
| if (options.local_command != NULL && |
| options.permit_local_command) |
| ssh_local_cmd(options.local_command); |
| |
| /* |
| * If requested and we are not interested in replies to remote |
| * forwarding requests, then let ssh continue in the background. |
| */ |
| if (fork_after_authentication_flag) { |
| if (options.exit_on_forward_failure && |
| options.num_remote_forwards > 0) { |
| debug("deferring postauth fork until remote forward " |
| "confirmation received"); |
| } else |
| fork_postauth(); |
| } |
| |
| /* |
| * 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); |
| } |
| |
| /* request pty/x11/agent/tcpfwd/shell for channel */ |
| static void |
| ssh_session2_setup(int id, int success, void *arg) |
| { |
| extern char **environ; |
| const char *display; |
| int interactive = tty_flag; |
| |
| if (!success) |
| return; /* No need for error message, channels code sens one */ |
| |
| display = getenv("DISPLAY"); |
| if (options.forward_x11 && display != NULL) { |
| char *proto, *data; |
| /* Get reasonable local authentication information. */ |
| client_x11_get_proto(display, options.xauth_location, |
| options.forward_x11_trusted, |
| options.forward_x11_timeout, &proto, &data); |
| /* Request forwarding with authentication spoofing. */ |
| debug("Requesting X11 forwarding with authentication " |
| "spoofing."); |
| x11_request_forwarding_with_spoofing(id, display, proto, |
| data, 1); |
| client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); |
| /* XXX exit_on_forward_failure */ |
| interactive = 1; |
| } |
| |
| check_agent_present(); |
| if (options.forward_agent) { |
| debug("Requesting authentication agent forwarding."); |
| channel_request_start(id, "auth-agent-req@openssh.com", 0); |
| packet_send(); |
| } |
| |
| /* Tell the packet module whether this is an interactive session. */ |
| packet_set_interactive(interactive, |
| options.ip_qos_interactive, options.ip_qos_bulk); |
| |
| client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), |
| NULL, fileno(stdin), &command, environ); |
| } |
| |
| /* 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, |
| "client-session", /*nonblock*/0); |
| |
| debug3("ssh_session2_open: channel_new: %d", c->self); |
| |
| channel_send_open(c->self); |
| if (!no_shell_flag) |
| channel_register_open_confirm(c->self, |
| ssh_session2_setup, NULL); |
| |
| return c->self; |
| } |
| |
| static int |
| ssh_session2(void) |
| { |
| int id = -1; |
| |
| /* XXX should be pre-session */ |
| if (!options.control_persist) |
| ssh_init_stdio_forwarding(); |
| ssh_init_forwarding(); |
| |
| /* Start listening for multiplex clients */ |
| muxserver_listen(); |
| |
| /* |
| * If we are in control persist mode and have a working mux listen |
| * socket, then prepare to background ourselves and have a foreground |
| * client attach as a control slave. |
| * NB. we must save copies of the flags that we override for |
| * the backgrounding, since we defer attachment of the slave until |
| * after the connection is fully established (in particular, |
| * async rfwd replies have been received for ExitOnForwardFailure). |
| */ |
| if (options.control_persist && muxserver_sock != -1) { |
| ostdin_null_flag = stdin_null_flag; |
| ono_shell_flag = no_shell_flag; |
| orequest_tty = options.request_tty; |
| otty_flag = tty_flag; |
| stdin_null_flag = 1; |
| no_shell_flag = 1; |
| tty_flag = 0; |
| if (!fork_after_authentication_flag) |
| need_controlpersist_detach = 1; |
| fork_after_authentication_flag = 1; |
| } |
| /* |
| * ControlPersist mux listen socket setup failed, attempt the |
| * stdio forward setup that we skipped earlier. |
| */ |
| if (options.control_persist && muxserver_sock == -1) |
| ssh_init_stdio_forwarding(); |
| |
| if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) |
| id = ssh_session2_open(); |
| else { |
| packet_set_interactive( |
| options.control_master == SSHCTL_MASTER_NO, |
| options.ip_qos_interactive, options.ip_qos_bulk); |
| } |
| |
| /* If we don't expect to open a new session, then disallow it */ |
| if (options.control_master == SSHCTL_MASTER_NO && |
| (datafellows & SSH_NEW_OPENSSH)) { |
| debug("Requesting no-more-sessions@openssh.com"); |
| packet_start(SSH2_MSG_GLOBAL_REQUEST); |
| packet_put_cstring("no-more-sessions@openssh.com"); |
| packet_put_char(0); |
| packet_send(); |
| } |
| |
| /* Execute a local command */ |
| if (options.local_command != NULL && |
| options.permit_local_command) |
| ssh_local_cmd(options.local_command); |
| |
| /* |
| * If requested and we are not interested in replies to remote |
| * forwarding requests, then let ssh continue in the background. |
| */ |
| if (fork_after_authentication_flag) { |
| if (options.exit_on_forward_failure && |
| options.num_remote_forwards > 0) { |
| debug("deferring postauth fork until remote forward " |
| "confirmation received"); |
| } else |
| fork_postauth(); |
| } |
| |
| if (options.use_roaming) |
| request_roaming(); |
| |
| return client_loop(tty_flag, tty_flag ? |
| options.escape_char : SSH_ESCAPECHAR_NONE, id); |
| } |
| |
| static void |
| load_public_identity_files(void) |
| { |
| char *filename, *cp, thishost[NI_MAXHOST]; |
| char *pwdir = NULL, *pwname = NULL; |
| int i = 0; |
| Key *public; |
| struct passwd *pw; |
| u_int n_ids; |
| char *identity_files[SSH_MAX_IDENTITY_FILES]; |
| Key *identity_keys[SSH_MAX_IDENTITY_FILES]; |
| #ifdef ENABLE_PKCS11 |
| Key **keys; |
| int nkeys; |
| #endif /* PKCS11 */ |
| |
| n_ids = 0; |
| memset(identity_files, 0, sizeof(identity_files)); |
| memset(identity_keys, 0, sizeof(identity_keys)); |
| |
| #ifdef ENABLE_PKCS11 |
| if (options.pkcs11_provider != NULL && |
| options.num_identity_files < SSH_MAX_IDENTITY_FILES && |
| (pkcs11_init(!options.batch_mode) == 0) && |
| (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, |
| &keys)) > 0) { |
| for (i = 0; i < nkeys; i++) { |
| if (n_ids >= SSH_MAX_IDENTITY_FILES) { |
| key_free(keys[i]); |
| continue; |
| } |
| identity_keys[n_ids] = keys[i]; |
| identity_files[n_ids] = |
| xstrdup(options.pkcs11_provider); /* XXX */ |
| n_ids++; |
| } |
| free(keys); |
| } |
| #endif /* ENABLE_PKCS11 */ |
| if ((pw = getpwuid(original_real_uid)) == NULL) |
| fatal("load_public_identity_files: getpwuid failed"); |
| pwname = xstrdup(pw->pw_name); |
| pwdir = xstrdup(pw->pw_dir); |
| if (gethostname(thishost, sizeof(thishost)) == -1) |
| fatal("load_public_identity_files: gethostname: %s", |
| strerror(errno)); |
| for (i = 0; i < options.num_identity_files; i++) { |
| if (n_ids >= SSH_MAX_IDENTITY_FILES || |
| strcasecmp(options.identity_files[i], "none") == 0) { |
| free(options.identity_files[i]); |
| continue; |
| } |
| cp = tilde_expand_filename(options.identity_files[i], |
| original_real_uid); |
| filename = percent_expand(cp, "d", pwdir, |
| "u", pwname, "l", thishost, "h", host, |
| "r", options.user, (char *)NULL); |
| free(cp); |
| public = key_load_public(filename, NULL); |
| debug("identity file %s type %d", filename, |
| public ? public->type : -1); |
| free(options.identity_files[i]); |
| identity_files[n_ids] = filename; |
| identity_keys[n_ids] = public; |
| |
| if (++n_ids >= SSH_MAX_IDENTITY_FILES) |
| continue; |
| |
| /* Try to add the certificate variant too */ |
| xasprintf(&cp, "%s-cert", filename); |
| public = key_load_public(cp, NULL); |
| debug("identity file %s type %d", cp, |
| public ? public->type : -1); |
| if (public == NULL) { |
| free(cp); |
| continue; |
| } |
| if (!key_is_cert(public)) { |
| debug("%s: key %s type %s is not a certificate", |
| __func__, cp, key_type(public)); |
| key_free(public); |
| free(cp); |
| continue; |
| } |
| identity_keys[n_ids] = public; |
| /* point to the original path, most likely the private key */ |
| identity_files[n_ids] = xstrdup(filename); |
| n_ids++; |
| } |
| options.num_identity_files = n_ids; |
| memcpy(options.identity_files, identity_files, sizeof(identity_files)); |
| memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); |
| |
| explicit_bzero(pwname, strlen(pwname)); |
| free(pwname); |
| explicit_bzero(pwdir, strlen(pwdir)); |
| free(pwdir); |
| } |
| |
| static void |
| main_sigchld_handler(int sig) |
| { |
| int save_errno = errno; |
| pid_t pid; |
| int status; |
| |
| while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
| (pid < 0 && errno == EINTR)) |
| ; |
| |
| signal(sig, main_sigchld_handler); |
| errno = save_errno; |
| } |