diff options
author | des <des@FreeBSD.org> | 2008-07-22 18:58:19 +0000 |
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committer | des <des@FreeBSD.org> | 2008-07-22 18:58:19 +0000 |
commit | 666aa9cc1660793c97ef29a6cb66dfbb894dde8f (patch) | |
tree | 209e642fbe2a816041f67bc27c9800879f5541bc /crypto/openssh/ssh.c | |
parent | 624d93001f28e236c027516d88282351eb7bffbe (diff) | |
download | FreeBSD-src-666aa9cc1660793c97ef29a6cb66dfbb894dde8f.zip FreeBSD-src-666aa9cc1660793c97ef29a6cb66dfbb894dde8f.tar.gz |
Revert part of 180714 - the intent was to flatten dist, not to nuke it.
Diffstat (limited to 'crypto/openssh/ssh.c')
-rw-r--r-- | crypto/openssh/ssh.c | 1484 |
1 files changed, 1484 insertions, 0 deletions
diff --git a/crypto/openssh/ssh.c b/crypto/openssh/ssh.c new file mode 100644 index 0000000..47297ed --- /dev/null +++ b/crypto/openssh/ssh.c @@ -0,0 +1,1484 @@ +/* $OpenBSD: ssh.c,v 1.294 2006/10/06 02:29:19 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/socket.h> +#include <sys/un.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 "xmalloc.h" +#include "ssh.h" +#include "ssh1.h" +#include "ssh2.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 "monitor_fdpass.h" +#include "uidswap.h" +#include "version.h" + +#ifdef SMARTCARD +#include "scard.h" +#endif + +extern char *__progname; + +/* Flag indicating whether debug mode is on. This can be set on the command line. */ +int debug_flag = 0; + +/* Flag indicating whether a tty should be allocated */ +int tty_flag = 0; +int no_tty_flag = 0; +int force_tty_flag = 0; + +/* don't exec a shell */ +int no_shell_flag = 0; + +/* + * Flag indicating that nothing should be read from stdin. This can be set + * on the command line. + */ +int stdin_null_flag = 0; + +/* + * Flag indicating that ssh should fork after authentication. This is useful + * so that the passphrase can be entered manually, and then ssh goes to the + * background. + */ +int fork_after_authentication_flag = 0; + +/* + * General data structure for command line options and options configurable + * in configuration files. See readconf.h. + */ +Options options; + +/* optional user configfile */ +char *config = NULL; + +/* + * Name of the host we are connecting to. This is the name given on the + * command line, or the HostName specified for the user-supplied name in a + * configuration file. + */ +char *host; + +/* socket address the host resolves to */ +struct sockaddr_storage hostaddr; + +/* Private host keys. */ +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 client_global_request_id = 0; + +/* pid of proxycommand child process */ +pid_t proxy_command_pid = 0; + +/* fd to control socket */ +int control_fd = -1; + +/* Multiplexing control command */ +static u_int mux_command = 0; + +/* Only used in control client mode */ +volatile sig_atomic_t control_client_terminate = 0; +u_int control_server_pid = 0; + +/* Prints a help message to the user. This function never returns. */ + +static void +usage(void) +{ + fprintf(stderr, +"usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" +" [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" +" [-i identity_file] [-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 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 control_client(const char *path); + +/* + * Main program for the ssh client. + */ +int +main(int ac, char **av) +{ + int i, opt, exit_status; + char *p, *cp, *line, buf[256]; + struct stat st; + struct passwd *pw; + int dummy; + 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]); + init_rng(); + + /* + * Save the original real uid. It will be needed later (uid-swapping + * may clobber the real uid). + */ + original_real_uid = getuid(); + original_effective_uid = geteuid(); + + /* + * 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; + + again: + while ((opt = getopt(ac, av, + "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -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': + options.forward_x11 = 1; + options.forward_x11_trusted = 1; + break; + case 'g': + options.gateway_ports = 1; + break; + case 'O': + if (strcmp(optarg, "check") == 0) + mux_command = SSHMUX_COMMAND_ALIVE_CHECK; + else if (strcmp(optarg, "exit") == 0) + mux_command = SSHMUX_COMMAND_TERMINATE; + 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 '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 SMARTCARD + options.smartcard_device = xstrdup(optarg); +#else + fprintf(stderr, "no support for smartcards.\n"); +#endif + break; + case 't': + if (tty_flag) + force_tty_flag = 1; + tty_flag = 1; + break; + case 'v': + if (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 '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)) + 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)) { + add_remote_forward(&options, &fwd); + } else { + fprintf(stderr, + "Bad remote forwarding specification " + "'%s'\n", optarg); + exit(255); + } + break; + + case 'D': + cp = p = xstrdup(optarg); + memset(&fwd, '\0', sizeof(fwd)); + fwd.connect_host = "socks"; + if ((fwd.listen_host = hpdelim(&cp)) == NULL) { + fprintf(stderr, "Bad dynamic forwarding " + "specification '%.100s'\n", optarg); + exit(255); + } + if (cp != NULL) { + fwd.listen_port = a2port(cp); + fwd.listen_host = cleanhostname(fwd.listen_host); + } else { + fwd.listen_port = a2port(fwd.listen_host); + fwd.listen_host = NULL; + } + + if (fwd.listen_port == 0) { + fprintf(stderr, "Bad dynamic port '%s'\n", + optarg); + exit(255); + } + add_local_forward(&options, &fwd); + xfree(p); + break; + + case 'C': + options.compression = 1; + break; + case 'N': + no_shell_flag = 1; + no_tty_flag = 1; + break; + case 'T': + no_tty_flag = 1; + break; + case 'o': + dummy = 1; + 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 && **av != '-') { + 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(); + + SSLeay_add_all_algorithms(); + ERR_load_crypto_strings(); + + /* Initialize the command to execute on remote host. */ + buffer_init(&command); + + /* + * Save the command to execute on the remote host in a buffer. There + * is no limit on the length of the command, except by the maximum + * packet size. Also sets the tty flag if there is no command. + */ + if (!ac) { + /* No command specified - execute shell on a tty. */ + tty_flag = 1; + if (subsystem_flag) { + fprintf(stderr, + "You must specify a subsystem to invoke.\n"); + usage(); + } + } else { + /* A command has been specified. Store it into the buffer. */ + for (i = 0; i < ac; i++) { + if (i) + buffer_append(&command, " ", 1); + buffer_append(&command, av[i], strlen(av[i])); + } + } + + /* Cannot fork to background if no command. */ + if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag) + fatal("Cannot fork into background without a command to execute."); + + /* Allocate a tty by default if no command specified. */ + if (buffer_len(&command) == 0) + tty_flag = 1; + + /* Force no tty */ + if (no_tty_flag) + tty_flag = 0; + /* Do not allocate a tty if stdin is not a tty. */ + if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { + 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(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, + SYSLOG_FACILITY_USER, 1); + + /* + * Read per-user configuration file. Ignore the system wide config + * file if the user specifies a config file on the command line. + */ + if (config != NULL) { + if (!read_config_file(config, host, &options, 0)) + fatal("Can't open user config file %.100s: " + "%.100s", config, strerror(errno)); + } else { + snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, + _PATH_SSH_USER_CONFFILE); + (void)read_config_file(buf, host, &options, 1); + + /* Read systemwide configuration file after use 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(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); + + seed_rng(); + + if (options.user == NULL) + options.user = xstrdup(pw->pw_name); + + if (options.hostname != NULL) + host = options.hostname; + + /* 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); + } + + /* 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; + } + + if (options.proxy_command != NULL && + strcmp(options.proxy_command, "none") == 0) + options.proxy_command = NULL; + if (options.control_path != NULL && + strcmp(options.control_path, "none") == 0) + options.control_path = NULL; + + if (options.control_path != NULL) { + char thishost[NI_MAXHOST]; + + if (gethostname(thishost, sizeof(thishost)) == -1) + fatal("gethostname: %s", strerror(errno)); + snprintf(buf, sizeof(buf), "%d", options.port); + cp = tilde_expand_filename(options.control_path, + original_real_uid); + options.control_path = percent_expand(cp, "p", buf, "h", host, + "r", options.user, "l", thishost, (char *)NULL); + xfree(cp); + } + if (mux_command != 0 && options.control_path == NULL) + fatal("No ControlPath specified for \"-O\" command"); + if (options.control_path != NULL) + control_client(options.control_path); + + /* Open a connection to the remote host. */ + if (ssh_connect(host, &hostaddr, options.port, + options.address_family, options.connection_attempts, +#ifdef HAVE_CYGWIN + options.use_privileged_port, +#else + original_effective_uid == 0 && options.use_privileged_port, +#endif + options.proxy_command) != 0) + exit(255); + + /* + * 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 = 3; + sensitive_data.keys = xcalloc(sensitive_data.nkeys, + sizeof(Key)); + + 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_type(KEY_DSA, + _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); + sensitive_data.keys[2] = 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[1] == NULL && + sensitive_data.keys[2] == NULL) { + sensitive_data.keys[1] = key_load_public( + _PATH_HOST_DSA_KEY_FILE, NULL); + sensitive_data.keys[2] = 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. + */ + snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); + if (stat(buf, &st) < 0) + if (mkdir(buf, 0700) < 0) + error("Could not create directory '%.200s'.", buf); + + /* load options.identity_files */ + load_public_identity_files(); + + /* Expand ~ in known host file names. */ + /* XXX mem-leaks: */ + options.system_hostfile = + tilde_expand_filename(options.system_hostfile, original_real_uid); + options.user_hostfile = + tilde_expand_filename(options.user_hostfile, original_real_uid); + options.system_hostfile2 = + tilde_expand_filename(options.system_hostfile2, original_real_uid); + options.user_hostfile2 = + tilde_expand_filename(options.user_hostfile2, original_real_uid); + + signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ + + /* Log into the remote system. This never returns if the login fails. */ + ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw); + + /* We no longer need the private host keys. Clear them now. */ + if (sensitive_data.nkeys != 0) { + for (i = 0; i < sensitive_data.nkeys; i++) { + if (sensitive_data.keys[i] != NULL) { + /* Destroys contents safely */ + debug3("clear hostkey %d", i); + key_free(sensitive_data.keys[i]); + sensitive_data.keys[i] = NULL; + } + } + xfree(sensitive_data.keys); + } + for (i = 0; i < options.num_identity_files; i++) { + if (options.identity_files[i]) { + xfree(options.identity_files[i]); + options.identity_files[i] = NULL; + } + if (options.identity_keys[i]) { + key_free(options.identity_keys[i]); + options.identity_keys[i] = NULL; + } + } + + exit_status = compat20 ? ssh_session2() : ssh_session(); + packet_close(); + + if (options.control_path != NULL && control_fd != -1) + unlink(options.control_path); + + /* + * Send SIGHUP to proxy command if used. We don't wait() in + * case it hangs and instead rely on init to reap the child + */ + if (proxy_command_pid > 1) + kill(proxy_command_pid, SIGHUP); + + return exit_status; +} + +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); + 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."); + } + } +} + +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, &proto, &data); + /* Request forwarding with authentication spoofing. */ + debug("Requesting X11 forwarding with authentication spoofing."); + x11_request_forwarding_with_spoofing(0, display, proto, data); + + /* 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); + + /* 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(); + + /* If requested, let ssh continue in the background. */ + if (fork_after_authentication_flag) + if (daemon(1, 1) < 0) + fatal("daemon() failed: %.200s", strerror(errno)); + + /* + * If a command was specified on the command line, execute the + * command now. Otherwise request the server to start a shell. + */ + if (buffer_len(&command) > 0) { + int len = buffer_len(&command); + if (len > 900) + len = 900; + debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); + packet_start(SSH_CMSG_EXEC_CMD); + packet_put_string(buffer_ptr(&command), buffer_len(&command)); + packet_send(); + packet_write_wait(); + } else { + debug("Requesting shell."); + packet_start(SSH_CMSG_EXEC_SHELL); + packet_send(); + packet_write_wait(); + } + + /* Enter the interactive session. */ + return client_loop(have_tty, tty_flag ? + options.escape_char : SSH_ESCAPECHAR_NONE, 0); +} + +static void +ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt) +{ + int id, len; + + id = packet_get_int(); + len = buffer_len(&command); + if (len > 900) + len = 900; + packet_check_eom(); + if (type == SSH2_MSG_CHANNEL_FAILURE) + fatal("Request for subsystem '%.*s' failed on channel %d", + len, (u_char *)buffer_ptr(&command), id); +} + +void +client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt) +{ + int i; + + i = client_global_request_id++; + if (i >= options.num_remote_forwards) + return; + debug("remote forward %s for: listen %d, connect %s:%d", + type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", + options.remote_forwards[i].listen_port, + options.remote_forwards[i].connect_host, + options.remote_forwards[i].connect_port); + if (type == SSH2_MSG_REQUEST_FAILURE) { + if (options.exit_on_forward_failure) + fatal("Error: remote port forwarding failed for " + "listen port %d", + options.remote_forwards[i].listen_port); + else + logit("Warning: remote port forwarding failed for " + "listen port %d", + options.remote_forwards[i].listen_port); + } +} + +static void +ssh_control_listener(void) +{ + struct sockaddr_un addr; + mode_t old_umask; + int addr_len; + + if (options.control_path == NULL || + options.control_master == SSHCTL_MASTER_NO) + return; + + debug("setting up multiplex master socket"); + + memset(&addr, '\0', sizeof(addr)); + addr.sun_family = AF_UNIX; + addr_len = offsetof(struct sockaddr_un, sun_path) + + strlen(options.control_path) + 1; + + if (strlcpy(addr.sun_path, options.control_path, + sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) + fatal("ControlPath too long"); + + if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) + fatal("%s socket(): %s", __func__, strerror(errno)); + + old_umask = umask(0177); + if (bind(control_fd, (struct sockaddr *)&addr, addr_len) == -1) { + control_fd = -1; + if (errno == EINVAL || errno == EADDRINUSE) + fatal("ControlSocket %s already exists", + options.control_path); + else + fatal("%s bind(): %s", __func__, strerror(errno)); + } + umask(old_umask); + + if (listen(control_fd, 64) == -1) + fatal("%s listen(): %s", __func__, strerror(errno)); + + set_nonblock(control_fd); +} + +/* request pty/x11/agent/tcpfwd/shell for channel */ +static void +ssh_session2_setup(int id, void *arg) +{ + extern char **environ; + const char *display; + int interactive = tty_flag; + + 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, &proto, &data); + /* Request forwarding with authentication spoofing. */ + debug("Requesting X11 forwarding with authentication spoofing."); + x11_request_forwarding_with_spoofing(id, display, proto, data); + interactive = 1; + /* XXX wait for reply */ + } + + check_agent_present(); + if (options.forward_agent) { + debug("Requesting authentication agent forwarding."); + channel_request_start(id, "auth-agent-req@openssh.com", 0); + packet_send(); + } + + if (options.tun_open != SSH_TUNMODE_NO) { + Channel *c; + int fd; + + debug("Requesting tun."); + if ((fd = tun_open(options.tun_local, + options.tun_open)) >= 0) { + c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, + CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, + 0, "tun", 1); + c->datagram = 1; +#if defined(SSH_TUN_FILTER) + if (options.tun_open == SSH_TUNMODE_POINTOPOINT) + channel_register_filter(c->self, sys_tun_infilter, + sys_tun_outfilter); +#endif + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring("tun@openssh.com"); + packet_put_int(c->self); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + packet_put_int(options.tun_open); + packet_put_int(options.tun_remote); + packet_send(); + } + } + + client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), + NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply); + + packet_set_interactive(interactive); +} + +/* open new channel for a session */ +static int +ssh_session2_open(void) +{ + Channel *c; + int window, packetmax, in, out, err; + + if (stdin_null_flag) { + in = open(_PATH_DEVNULL, O_RDONLY); + } else { + in = dup(STDIN_FILENO); + } + out = dup(STDOUT_FILENO); + err = dup(STDERR_FILENO); + + if (in < 0 || out < 0 || err < 0) + fatal("dup() in/out/err failed"); + + /* enable nonblocking unless tty */ + if (!isatty(in)) + set_nonblock(in); + if (!isatty(out)) + set_nonblock(out); + if (!isatty(err)) + set_nonblock(err); + + window = CHAN_SES_WINDOW_DEFAULT; + packetmax = CHAN_SES_PACKET_DEFAULT; + if (tty_flag) { + window >>= 1; + packetmax >>= 1; + } + c = channel_new( + "session", SSH_CHANNEL_OPENING, in, out, err, + window, packetmax, CHAN_EXTENDED_WRITE, + "client-session", /*nonblock*/0); + + debug3("ssh_session2_open: channel_new: %d", c->self); + + channel_send_open(c->self); + if (!no_shell_flag) + channel_register_confirm(c->self, ssh_session2_setup, NULL); + + return c->self; +} + +static int +ssh_session2(void) +{ + int id = -1; + + /* XXX should be pre-session */ + ssh_init_forwarding(); + ssh_control_listener(); + + if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) + id = ssh_session2_open(); + + /* Execute a local command */ + if (options.local_command != NULL && + options.permit_local_command) + ssh_local_cmd(options.local_command); + + /* If requested, let ssh continue in the background. */ + if (fork_after_authentication_flag) + if (daemon(1, 1) < 0) + fatal("daemon() failed: %.200s", strerror(errno)); + + return client_loop(tty_flag, tty_flag ? + options.escape_char : SSH_ESCAPECHAR_NONE, id); +} + +static void +load_public_identity_files(void) +{ + char *filename, *cp, thishost[NI_MAXHOST]; + int i = 0; + Key *public; + struct passwd *pw; +#ifdef SMARTCARD + Key **keys; + + if (options.smartcard_device != NULL && + options.num_identity_files < SSH_MAX_IDENTITY_FILES && + (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) { + int count = 0; + for (i = 0; keys[i] != NULL; i++) { + count++; + memmove(&options.identity_files[1], &options.identity_files[0], + sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1)); + memmove(&options.identity_keys[1], &options.identity_keys[0], + sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1)); + options.num_identity_files++; + options.identity_keys[0] = keys[i]; + options.identity_files[0] = sc_get_key_label(keys[i]); + } + if (options.num_identity_files > SSH_MAX_IDENTITY_FILES) + options.num_identity_files = SSH_MAX_IDENTITY_FILES; + i = count; + xfree(keys); + } +#endif /* SMARTCARD */ + if ((pw = getpwuid(original_real_uid)) == NULL) + fatal("load_public_identity_files: getpwuid failed"); + if (gethostname(thishost, sizeof(thishost)) == -1) + fatal("load_public_identity_files: gethostname: %s", + strerror(errno)); + for (; i < options.num_identity_files; i++) { + cp = tilde_expand_filename(options.identity_files[i], + original_real_uid); + filename = percent_expand(cp, "d", pw->pw_dir, + "u", pw->pw_name, "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]); + options.identity_files[i] = filename; + options.identity_keys[i] = public; + } +} + +static void +control_client_sighandler(int signo) +{ + control_client_terminate = signo; +} + +static void +control_client_sigrelay(int signo) +{ + if (control_server_pid > 1) + kill(control_server_pid, signo); +} + +static int +env_permitted(char *env) +{ + int i, ret; + char name[1024], *cp; + + if ((cp = strchr(env, '=')) == NULL || cp == env) + return (0); + ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); + if (ret <= 0 || (size_t)ret >= sizeof(name)) + fatal("env_permitted: name '%.100s...' too long", env); + + for (i = 0; i < options.num_send_env; i++) + if (match_pattern(name, options.send_env[i])) + return (1); + + return (0); +} + +static void +control_client(const char *path) +{ + struct sockaddr_un addr; + int i, r, fd, sock, exitval, num_env, addr_len; + Buffer m; + char *term; + extern char **environ; + u_int flags; + + if (mux_command == 0) + mux_command = SSHMUX_COMMAND_OPEN; + + switch (options.control_master) { + case SSHCTL_MASTER_AUTO: + case SSHCTL_MASTER_AUTO_ASK: + debug("auto-mux: Trying existing master"); + /* FALLTHROUGH */ + case SSHCTL_MASTER_NO: + break; + default: + return; + } + + memset(&addr, '\0', sizeof(addr)); + addr.sun_family = AF_UNIX; + addr_len = offsetof(struct sockaddr_un, sun_path) + + strlen(path) + 1; + + if (strlcpy(addr.sun_path, path, + sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) + fatal("ControlPath too long"); + + if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) + fatal("%s socket(): %s", __func__, strerror(errno)); + + if (connect(sock, (struct sockaddr *)&addr, addr_len) == -1) { + if (mux_command != SSHMUX_COMMAND_OPEN) { + fatal("Control socket connect(%.100s): %s", path, + strerror(errno)); + } + if (errno == ENOENT) + debug("Control socket \"%.100s\" does not exist", path); + else { + error("Control socket connect(%.100s): %s", path, + strerror(errno)); + } + close(sock); + return; + } + + if (stdin_null_flag) { + if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) + fatal("open(/dev/null): %s", strerror(errno)); + if (dup2(fd, STDIN_FILENO) == -1) + fatal("dup2: %s", strerror(errno)); + if (fd > STDERR_FILENO) + close(fd); + } + + term = getenv("TERM"); + + flags = 0; + if (tty_flag) + flags |= SSHMUX_FLAG_TTY; + if (subsystem_flag) + flags |= SSHMUX_FLAG_SUBSYS; + if (options.forward_x11) + flags |= SSHMUX_FLAG_X11_FWD; + if (options.forward_agent) + flags |= SSHMUX_FLAG_AGENT_FWD; + + buffer_init(&m); + + /* Send our command to server */ + buffer_put_int(&m, mux_command); + buffer_put_int(&m, flags); + if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) + fatal("%s: msg_send", __func__); + buffer_clear(&m); + + /* Get authorisation status and PID of controlee */ + if (ssh_msg_recv(sock, &m) == -1) + fatal("%s: msg_recv", __func__); + if (buffer_get_char(&m) != SSHMUX_VER) + fatal("%s: wrong version", __func__); + if (buffer_get_int(&m) != 1) + fatal("Connection to master denied"); + control_server_pid = buffer_get_int(&m); + + buffer_clear(&m); + + switch (mux_command) { + case SSHMUX_COMMAND_ALIVE_CHECK: + fprintf(stderr, "Master running (pid=%d)\r\n", + control_server_pid); + exit(0); + case SSHMUX_COMMAND_TERMINATE: + fprintf(stderr, "Exit request sent.\r\n"); + exit(0); + case SSHMUX_COMMAND_OPEN: + /* continue below */ + break; + default: + fatal("silly mux_command %d", mux_command); + } + + /* SSHMUX_COMMAND_OPEN */ + buffer_put_cstring(&m, term ? term : ""); + buffer_append(&command, "\0", 1); + buffer_put_cstring(&m, buffer_ptr(&command)); + + if (options.num_send_env == 0 || environ == NULL) { + buffer_put_int(&m, 0); + } else { + /* Pass environment */ + num_env = 0; + for (i = 0; environ[i] != NULL; i++) + if (env_permitted(environ[i])) + num_env++; /* Count */ + + buffer_put_int(&m, num_env); + + for (i = 0; environ[i] != NULL && num_env >= 0; i++) + if (env_permitted(environ[i])) { + num_env--; + buffer_put_cstring(&m, environ[i]); + } + } + + if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) + fatal("%s: msg_send", __func__); + + mm_send_fd(sock, STDIN_FILENO); + mm_send_fd(sock, STDOUT_FILENO); + mm_send_fd(sock, STDERR_FILENO); + + /* Wait for reply, so master has a chance to gather ttymodes */ + buffer_clear(&m); + if (ssh_msg_recv(sock, &m) == -1) + fatal("%s: msg_recv", __func__); + if (buffer_get_char(&m) != SSHMUX_VER) + fatal("%s: wrong version", __func__); + buffer_free(&m); + + signal(SIGHUP, control_client_sighandler); + signal(SIGINT, control_client_sighandler); + signal(SIGTERM, control_client_sighandler); + signal(SIGWINCH, control_client_sigrelay); + + if (tty_flag) + enter_raw_mode(); + + /* Stick around until the controlee closes the client_fd */ + exitval = 0; + for (;!control_client_terminate;) { + r = read(sock, &exitval, sizeof(exitval)); + if (r == 0) { + debug2("Received EOF from master"); + break; + } + if (r > 0) + debug2("Received exit status from master %d", exitval); + if (r == -1 && errno != EINTR) + fatal("%s: read %s", __func__, strerror(errno)); + } + + if (control_client_terminate) + debug2("Exiting on signal %d", control_client_terminate); + + close(sock); + + leave_raw_mode(); + + if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) + fprintf(stderr, "Connection to master closed.\r\n"); + + exit(exitval); +} |