diff options
Diffstat (limited to 'ssh.c')
| -rw-r--r-- | ssh.c | 1588 |
1 files changed, 0 insertions, 1588 deletions
@@ -1,1588 +0,0 @@ -/* $OpenBSD: ssh.c,v 1.364 2011/08/02 23:15:03 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> - -#include <openssl/evp.h> -#include <openssl/err.h> -#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 "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 escape_char] [-F configfile]\n" -" [-I pkcs11] [-i identity_file]\n" -" [-L [bind_address:]port:host:hostport]\n" -" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" -" [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" -" [-W host:port] [-w local_tun[:remote_tun]]\n" -" [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); - xfree(paths[i]); - paths[i] = cp; - } -} - -/* - * 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; - char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; - struct stat st; - struct passwd *pw; - int dummy, timeout_ms; - extern int optind, optreset; - extern char *optarg; - - struct servent *sp; - Forward fwd; - - /* 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("You don't exist, go away!"); - 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; - argv0 = av[0]; - - again: - while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" - "ACD:F:I:KL:MNO:PR: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 '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 - fatal("Invalid multiplex command."); - break; - case 'P': /* deprecated */ - options.use_privileged_port = 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; - } - 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 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; - } - /* FALLTHROUGH */ - case 'V': - fprintf(stderr, "%s, %s\n", - SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); - 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; - xfree(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': - dummy = 1; - line = xstrdup(optarg); - if (process_config_line(&options, host ? host : "", - line, "command-line", 0, &dummy) != 0) - exit(255); - xfree(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 = ++cp; - } else - host = *av; - if (ac > 1) { - optind = optreset = 1; - goto again; - } - ac--, av++; - } - - /* Check that we got a host name. */ - if (!host) - usage(); - - OpenSSL_add_all_algorithms(); - ERR_load_crypto_strings(); - - /* Initialize the command to execute on remote host. */ - buffer_init(&command); - - if (options.request_tty == REQUEST_TTY_YES || - options.request_tty == REQUEST_TTY_FORCE) - tty_flag = 1; - - /* - * 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 = options.request_tty != REQUEST_TTY_NO; - 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 = 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; - } - - /* - * Initialize "log" output. Since we are the client all output - * actually goes to stderr. - */ - log_init(argv0, - options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, - SYSLOG_FACILITY_USER, !use_syslog); - - /* - * 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, 0)) - 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, host, &options, 1); - - /* Read systemwide configuration file after user config. */ - (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, - &options, 0); - } - - /* Fill configuration defaults. */ - fill_default_options(&options); - - channel_set_af(options.address_family); - - /* reinit */ - log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); - - seed_rng(); - - if (options.user == NULL) - options.user = xstrdup(pw->pw_name); - - /* Get default port if port has not been set. */ - if (options.port == 0) { - sp = getservbyname(SSH_SERVICE_NAME, "tcp"); - options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; - } - - /* preserve host name given on command line for %n expansion */ - host_arg = host; - if (options.hostname != NULL) { - host = percent_expand(options.hostname, - "h", host, (char *)NULL); - } - - 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 (options.local_command != NULL) { - debug3("expanding LocalCommand: %s", options.local_command); - cp = options.local_command; - options.local_command = percent_expand(cp, "d", pw->pw_dir, - "h", host, "l", thishost, "n", host_arg, "r", options.user, - "p", portstr, "u", pw->pw_name, "L", shorthost, - (char *)NULL); - debug3("expanded LocalCommand: %s", options.local_command); - xfree(cp); - } - - /* force lowercase for hostkey matching */ - if (options.host_key_alias != NULL) { - for (p = options.host_key_alias; *p; p++) - if (isupper(*p)) - *p = (char)tolower(*p); - } - - if (options.proxy_command != NULL && - strcmp(options.proxy_command, "none") == 0) { - xfree(options.proxy_command); - options.proxy_command = NULL; - } - if (options.control_path != NULL && - strcmp(options.control_path, "none") == 0) { - xfree(options.control_path); - options.control_path = NULL; - } - - if (options.control_path != NULL) { - cp = tilde_expand_filename(options.control_path, - original_real_uid); - xfree(options.control_path); - options.control_path = percent_expand(cp, "h", host, - "l", thishost, "n", host_arg, "r", options.user, - "p", portstr, "u", pw->pw_name, "L", shorthost, - (char *)NULL); - xfree(cp); - } - if (muxclient_command != 0 && options.control_path == NULL) - fatal("No ControlPath specified for \"-O\" command"); - if (options.control_path != NULL) - muxclient(options.control_path); - - timeout_ms = options.connection_timeout * 1000; - - /* Open a connection to the remote host. */ - if (ssh_connect(host, &hostaddr, options.port, - options.address_family, options.connection_attempts, &timeout_ms, - options.tcp_keep_alive, -#ifdef HAVE_CYGWIN - options.use_privileged_port, -#else - original_effective_uid == 0 && options.use_privileged_port, -#endif - options.proxy_command) != 0) - exit(255); - - 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 = 7; - 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_type(KEY_DSA, - _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); -#ifdef OPENSSL_HAS_ECC - sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, - _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); -#endif - sensitive_data.keys[6] = key_load_private_type(KEY_RSA, - _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); - PRIV_END; - - if (options.hostbased_authentication == 1 && - sensitive_data.keys[0] == NULL && - sensitive_data.keys[4] == NULL && - sensitive_data.keys[5] == NULL && - sensitive_data.keys[6] == 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_public( - _PATH_HOST_DSA_KEY_FILE, NULL); -#ifdef OPENSSL_HAS_ECC - sensitive_data.keys[5] = key_load_public( - _PATH_HOST_ECDSA_KEY_FILE, NULL); -#endif - sensitive_data.keys[6] = key_load_public( - _PATH_HOST_RSA_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. - */ - 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; - } - } - 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(); - - 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); - } - 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 %d, connect %s:%d", - type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", - rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); - if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) { - 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); - } - - 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 int -client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect) -{ - Channel *c; - int in, out; - - debug3("client_setup_stdio_fwd %s:%d", host_to_connect, - port_to_connect); - - in = dup(STDIN_FILENO); - out = dup(STDOUT_FILENO); - if (in < 0 || out < 0) - fatal("channel_connect_stdio_fwd: dup() in/out failed"); - - if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect, - in, out)) == NULL) - return 0; - channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); - return 1; -} - -static void -ssh_init_forwarding(void) -{ - int success = 0; - int i; - - if (stdio_forward_host != NULL) { - if (!compat20) { - fatal("stdio forwarding require Protocol 2"); - } - if (!client_setup_stdio_fwd(stdio_forward_host, - stdio_forward_port)) - fatal("Failed to connect in stdio forward mode."); - } - - /* 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); - if (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) < 0) { - if (options.exit_on_forward_failure) - fatal("Could not request remote forwarding."); - else - logit("Warning: Could not request remote " - "forwarding."); - } - 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_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(); - } - - 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 */ - ssh_init_forwarding(); - - /* Start listening for multiplex clients */ - muxserver_listen(); - - /* - * If we are in control persist mode, 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; - } - - if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) - id = ssh_session2_open(); - - /* 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; - bzero(identity_files, sizeof(identity_files)); - bzero(identity_keys, 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++; - } - xfree(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) { - xfree(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); - xfree(cp); - public = key_load_public(filename, NULL); - debug("identity file %s type %d", filename, - public ? public->type : -1); - xfree(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) { - xfree(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); - xfree(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)); - - bzero(pwname, strlen(pwname)); - xfree(pwname); - bzero(pwdir, strlen(pwdir)); - xfree(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; -} - |