X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/96ee83868809f6ddea859fe398a8560e992b08c7..5d97cfbf8be086f7495f35675e967358d2babb7d:/ssh.c diff --git a/ssh.c b/ssh.c index 7db19f3b..bd0d5ba9 100644 --- a/ssh.c +++ b/ssh.c @@ -39,7 +39,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: ssh.c,v 1.97 2001/02/21 21:14:04 stevesk Exp $"); +RCSID("$OpenBSD: ssh.c,v 1.115 2001/04/14 16:33:20 stevesk Exp $"); #include #include @@ -67,6 +67,7 @@ RCSID("$OpenBSD: ssh.c,v 1.97 2001/02/21 21:14:04 stevesk Exp $"); #include "misc.h" #include "kex.h" #include "mac.h" +#include "sshtty.h" #ifdef HAVE___PROGNAME extern char *__progname; @@ -130,11 +131,11 @@ struct sockaddr_storage hostaddr; */ volatile int received_window_change_signal = 0; -/* Flag indicating whether we have a valid host private key loaded. */ -int host_private_key_loaded = 0; - -/* Host private key. */ -RSA *host_private_key = NULL; +/* Private host keys. */ +struct { + Key **keys; + int nkeys; +} sensitive_data; /* Original real UID. */ uid_t original_real_uid; @@ -161,8 +162,8 @@ usage(void) #endif /* AFS */ fprintf(stderr, " -X Enable X11 connection forwarding.\n"); fprintf(stderr, " -x Disable X11 connection forwarding.\n"); - fprintf(stderr, " -i file Identity for public key authentication\n"); - fprintf(stderr, " (default: ~/.ssh/identity).\n"); + fprintf(stderr, " -i file Identity for public key authentication " + "(default: ~/.ssh/identity)\n"); fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n"); fprintf(stderr, " -T Do not allocate a tty.\n"); fprintf(stderr, " -v Verbose; display verbose debugging messages.\n"); @@ -174,13 +175,17 @@ usage(void) fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n"); fprintf(stderr, " -c cipher Select encryption algorithm: " - "``3des'', " - "``blowfish''\n"); + "``3des'', ``blowfish''\n"); + fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\n"); fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n"); fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n"); fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n"); fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname); fprintf(stderr, " forward them to the other side by connecting to host:port.\n"); + fprintf(stderr, " -D port Dynamically forward local port to multiple remote addresses.\n"); + fprintf(stderr, " Allows %s to act as an application-layer proxy.\n", + __progname); + fprintf(stderr, " Protocols supported: SOCKS4, SOCKS5, HTTPS\n"); fprintf(stderr, " -C Enable compression.\n"); fprintf(stderr, " -N Do not execute a shell or command.\n"); fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n"); @@ -233,7 +238,7 @@ rsh_connect(char *host, char *user, Buffer * command) int ssh_session(void); int ssh_session2(void); -int guess_identity_file_type(const char *filename); +void load_public_identity_files(void); /* * Main program for the ssh client. @@ -245,7 +250,7 @@ main(int ac, char **av) u_short fwd_port, fwd_host_port; char *optarg, *cp, buf[256]; struct stat st; - struct passwd *pw, pwcopy; + struct passwd *pw; int dummy; uid_t original_effective_uid; @@ -268,6 +273,15 @@ main(int ac, char **av) fatal("setrlimit failed: %.100s", strerror(errno)); } #endif + /* Get user data. */ + pw = getpwuid(original_real_uid); + if (!pw) { + log("You don't exist, go away!"); + exit(1); + } + /* Take a copy of the returned structure. */ + pw = pwcopy(pw); + /* * Use uid-swapping to give up root privileges for the duration of * option processing. We will re-instantiate the rights when we are @@ -275,7 +289,7 @@ main(int ac, char **av) * them when the port has been created (actually, when the connection * has been made, as we may need to create the port several times). */ - temporarily_use_uid(original_real_uid); + temporarily_use_uid(pw); /* * Set our umask to something reasonable, as some files are created @@ -308,7 +322,7 @@ main(int ac, char **av) opt = av[optind][1]; if (!opt) usage(); - if (strchr("eilcmpLRo", opt)) { /* options with arguments */ + if (strchr("eilcmpLRDo", opt)) { /* options with arguments */ optarg = av[optind] + 2; if (strcmp(optarg, "") == 0) { if (optind >= ac - 1) @@ -388,7 +402,7 @@ main(int ac, char **av) options.log_level++; break; } else { - fatal("Too high debugging level.\n"); + fatal("Too high debugging level."); } /* fallthrough */ case 'V': @@ -447,7 +461,11 @@ main(int ac, char **av) } break; case 'p': - options.port = atoi(optarg); + options.port = a2port(optarg); + if (options.port == 0) { + fprintf(stderr, "Bad port '%s'\n", optarg); + exit(1); + } break; case 'l': options.user = optarg; @@ -474,6 +492,16 @@ main(int ac, char **av) } add_local_forward(&options, fwd_port, buf, fwd_host_port); break; + + case 'D': + fwd_port = a2port(optarg); + if (fwd_port == 0) { + fprintf(stderr, "Bad dynamic port '%s'\n", optarg); + exit(1); + } + add_local_forward(&options, fwd_port, "socks4", 0); + break; + case 'C': options.compression = 1; break; @@ -517,7 +545,7 @@ main(int ac, char **av) /* No command specified - execute shell on a tty. */ tty_flag = 1; if (subsystem_flag) { - fprintf(stderr, "You must specify a subsystem to invoke."); + fprintf(stderr, "You must specify a subsystem to invoke.\n"); usage(); } } else { @@ -544,32 +572,16 @@ main(int ac, char **av) /* Do not allocate a tty if stdin is not a tty. */ if (!isatty(fileno(stdin)) && !force_tty_flag) { if (tty_flag) - log("Pseudo-terminal will not be allocated because stdin is not a terminal.\n"); + log("Pseudo-terminal will not be allocated because stdin is not a terminal."); tty_flag = 0; } - /* Get user data. */ - pw = getpwuid(original_real_uid); - if (!pw) { - log("You don't exist, go away!\n"); - exit(1); - } - /* Take a copy of the returned structure. */ - memset(&pwcopy, 0, sizeof(pwcopy)); - pwcopy.pw_name = xstrdup(pw->pw_name); - pwcopy.pw_passwd = xstrdup(pw->pw_passwd); - pwcopy.pw_uid = pw->pw_uid; - pwcopy.pw_gid = pw->pw_gid; -#ifdef HAVE_PW_CLASS_IN_PASSWD - pwcopy.pw_class = xstrdup(pw->pw_class); -#endif - pwcopy.pw_dir = xstrdup(pw->pw_dir); - pwcopy.pw_shell = xstrdup(pw->pw_shell); - pw = &pwcopy; - - /* Initialize "log" output. Since we are the client all output - actually goes to the terminal. */ - log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0); + /* + * 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. */ snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, _PATH_SSH_USER_CONFFILE); @@ -582,7 +594,9 @@ main(int ac, char **av) fill_default_options(&options); /* reinit */ - log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0); + log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); + + seed_rng(); if (options.user == NULL) options.user = xstrdup(pw->pw_name); @@ -601,6 +615,7 @@ main(int ac, char **av) "originating port will not be trusted."); options.rhosts_authentication = 0; } + /* * If using rsh has been selected, exec it now (without trying * anything else). Note that we must release privileges first. @@ -613,7 +628,7 @@ main(int ac, char **av) restore_uid(); /* Switch to the original uid permanently. */ - permanently_set_uid(original_real_uid); + permanently_set_uid(pw); /* Execute rsh. */ rsh_connect(host, options.user, &command); @@ -627,8 +642,7 @@ main(int ac, char **av) ok = ssh_connect(host, &hostaddr, options.port, options.connection_attempts, original_effective_uid != 0 || !options.use_privileged_port, - original_real_uid, - options.proxy_command); + pw, options.proxy_command); /* * If we successfully made the connection, load the host private key @@ -636,13 +650,18 @@ main(int ac, char **av) * authentication. This must be done before releasing extra * privileges, because the file is only readable by root. */ - if (ok && (options.protocol & SSH_PROTO_1)) { - Key k; - host_private_key = RSA_new(); - k.type = KEY_RSA1; - k.rsa = host_private_key; - if (load_private_key(_PATH_HOST_KEY_FILE, "", &k, NULL)) - host_private_key_loaded = 1; + sensitive_data.nkeys = 0; + sensitive_data.keys = NULL; + if (ok && (options.rhosts_rsa_authentication || + options.hostbased_authentication)) { + sensitive_data.nkeys = 3; + sensitive_data.keys = xmalloc(sensitive_data.nkeys*sizeof(Key)); + sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, + _PATH_HOST_KEY_FILE, "", NULL); + sensitive_data.keys[1] = key_load_private_type(KEY_DSA, + _PATH_HOST_DSA_KEY_FILE, "", NULL); + sensitive_data.keys[2] = key_load_private_type(KEY_RSA, + _PATH_HOST_RSA_KEY_FILE, "", NULL); } /* * Get rid of any extra privileges that we may have. We will no @@ -659,7 +678,7 @@ main(int ac, char **av) * process, read the private hostkey and impersonate the host. * OpenBSD does not allow ptracing of setuid processes. */ - permanently_set_uid(original_real_uid); + permanently_set_uid(pw); /* * Now that we are back to our own permissions, create ~/.ssh @@ -686,15 +705,11 @@ main(int ac, char **av) } exit(1); } - /* Expand ~ in options.identity_files, known host file names. */ - /* XXX mem-leaks */ - for (i = 0; i < options.num_identity_files; i++) { - options.identity_files[i] = - tilde_expand_filename(options.identity_files[i], original_real_uid); - options.identity_files_type[i] = guess_identity_file_type(options.identity_files[i]); - debug("identity file %s type %d", options.identity_files[i], - options.identity_files_type[i]); - } + /* 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 = @@ -705,12 +720,21 @@ main(int ac, char **av) tilde_expand_filename(options.user_hostfile2, original_real_uid); /* Log into the remote system. This never returns if the login fails. */ - ssh_login(host_private_key_loaded, host_private_key, - host, (struct sockaddr *)&hostaddr, original_real_uid); - - /* We no longer need the host private key. Clear it now. */ - if (host_private_key_loaded) - RSA_free(host_private_key); /* Destroys contents safely */ + ssh_login(sensitive_data.keys, sensitive_data.nkeys, + host, (struct sockaddr *)&hostaddr, pw); + + /* We no longer need the private host keys. Clear them now. */ + if (sensitive_data.nkeys != 0) { + for (i = 0; i < sensitive_data.nkeys; i++) { + if (sensitive_data.keys[i] != NULL) { + /* Destroys contents safely */ + debug3("clear hostkey %d", i); + key_free(sensitive_data.keys[i]); + sensitive_data.keys[i] = NULL; + } + } + xfree(sensitive_data.keys); + } exit_status = compat20 ? ssh_session2() : ssh_session(); packet_close(); @@ -856,7 +880,7 @@ ssh_session(void) packet_put_int(ws.ws_ypixel); /* Store tty modes in the packet. */ - tty_make_modes(fileno(stdin)); + tty_make_modes(fileno(stdin), NULL); /* Send the packet, and wait for it to leave. */ packet_send(); @@ -947,7 +971,8 @@ client_subsystem_reply(int type, int plen, void *ctxt) id = packet_get_int(); len = buffer_len(&command); - len = MAX(len, 900); + if (len > 900) + len = 900; packet_done(); if (type == SSH2_MSG_CHANNEL_FAILURE) fatal("Request for subsystem '%.*s' failed on channel %d", @@ -959,12 +984,10 @@ ssh_session2_callback(int id, void *arg) { int len; int interactive = 0; + struct termios tio; debug("client_init id %d arg %ld", id, (long)arg); - if (no_shell_flag) - goto done; - if (tty_flag) { struct winsize ws; char *cp; @@ -981,7 +1004,8 @@ ssh_session2_callback(int id, void *arg) packet_put_int(ws.ws_row); packet_put_int(ws.ws_xpixel); packet_put_int(ws.ws_ypixel); - packet_put_cstring(""); /* XXX: encode terminal modes */ + tio = get_saved_tio(); + tty_make_modes(/*ignored*/ 0, &tio); packet_send(); interactive = 1; /* XXX wait for reply */ @@ -1020,22 +1044,21 @@ ssh_session2_callback(int id, void *arg) debug("Sending command: %.*s", len, buffer_ptr(&command)); channel_request_start(id, "exec", 0); } - packet_put_string(buffer_ptr(&command), len); + packet_put_string(buffer_ptr(&command), buffer_len(&command)); packet_send(); } else { channel_request(id, "shell", 0); } /* channel_callback(id, SSH2_MSG_OPEN_CONFIGMATION, client_init, 0); */ -done: /* register different callback, etc. XXX */ packet_set_interactive(interactive); } int -ssh_session2(void) +ssh_session2_command(void) { - int window, packetmax, id; + int id, window, packetmax; int in, out, err; if (stdin_null_flag) { @@ -1057,14 +1080,6 @@ ssh_session2(void) if (!isatty(err)) set_nonblock(err); - /* XXX should be pre-session */ - 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)); - window = CHAN_SES_WINDOW_DEFAULT; packetmax = CHAN_SES_PACKET_DEFAULT; if (!tty_flag) { @@ -1076,29 +1091,48 @@ ssh_session2(void) window, packetmax, CHAN_EXTENDED_WRITE, xstrdup("client-session"), /*nonblock*/0); +debug("channel_new: %d", id); + channel_open(id); channel_register_callback(id, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, ssh_session2_callback, (void *)0); - return client_loop(tty_flag, tty_flag ? options.escape_char : -1, id); + return id; } int -guess_identity_file_type(const char *filename) +ssh_session2(void) { - struct stat st; + int id; + + /* XXX should be pre-session */ + ssh_init_forwarding(); + + id = no_shell_flag ? -1 : ssh_session2_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 : -1, id); +} + +void +load_public_identity_files(void) +{ + char *filename; Key *public; - int type = KEY_RSA1; /* default */ + int i; - if (stat(filename, &st) < 0) { - /* ignore this key */ - return KEY_UNSPEC; - } - public = key_new(type); - if (!load_public_key(filename, public, NULL)) { - /* ok, so we will assume this is 'some' key */ - type = KEY_UNSPEC; + for (i = 0; i < options.num_identity_files; i++) { + filename = tilde_expand_filename(options.identity_files[i], + original_real_uid); + public = key_load_public(filename, NULL); + debug("identity file %s type %d", filename, + public ? public->type : -1); + xfree(options.identity_files[i]); + options.identity_files[i] = filename; + options.identity_keys[i] = public; } - key_free(public); - return type; }