=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh.c,v retrieving revision 1.201 retrieving revision 1.201.2.2 diff -u -r1.201 -r1.201.2.2 --- src/usr.bin/ssh/ssh.c 2003/09/01 18:15:50 1.201 +++ src/usr.bin/ssh/ssh.c 2004/08/19 22:37:32 1.201.2.2 @@ -13,7 +13,7 @@ * called by a name other than "ssh" or "Secure Shell". * * Copyright (c) 1999 Niels Provos. All rights reserved. - * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved. + * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. * * Modified to work with SSL by Niels Provos * in Canada (German citizen). @@ -40,7 +40,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: ssh.c,v 1.201 2003/09/01 18:15:50 markus Exp $"); +RCSID("$OpenBSD: ssh.c,v 1.201.2.2 2004/08/19 22:37:32 brad Exp $"); #include #include @@ -53,21 +53,24 @@ #include "xmalloc.h" #include "packet.h" #include "buffer.h" +#include "bufaux.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 "tildexpand.h" -#include "dispatch.h" #include "misc.h" #include "kex.h" #include "mac.h" -#include "sshtty.h" +#include "sshpty.h" +#include "match.h" +#include "msg.h" +#include "monitor_fdpass.h" #ifdef SMARTCARD #include "scard.h" @@ -137,59 +140,31 @@ /* pid of proxycommand child process */ pid_t proxy_command_pid = 0; +/* fd to control socket */ +int control_fd = -1; + +/* 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: %s [options] host [command]\n", __progname); - fprintf(stderr, "Options:\n"); - fprintf(stderr, " -l user Log in using this user name.\n"); - fprintf(stderr, " -n Redirect input from " _PATH_DEVNULL ".\n"); - fprintf(stderr, " -F config Config file (default: ~/%s).\n", - _PATH_SSH_USER_CONFFILE); - fprintf(stderr, " -A Enable authentication agent forwarding.\n"); - fprintf(stderr, " -a Disable authentication agent forwarding (default).\n"); - fprintf(stderr, " -X Enable X11 connection forwarding.\n"); - fprintf(stderr, " -x Disable X11 connection forwarding (default).\n"); - fprintf(stderr, " -i file Identity for public key authentication " - "(default: ~/.ssh/identity)\n"); -#ifdef SMARTCARD - fprintf(stderr, " -I reader Set smartcard reader.\n"); -#endif - fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n"); - fprintf(stderr, " -T Do not allocate a tty.\n"); - fprintf(stderr, " -v Verbose; display verbose debugging messages.\n"); - fprintf(stderr, " Multiple -v increases verbosity.\n"); - fprintf(stderr, " -V Display version number only.\n"); - fprintf(stderr, " -q Quiet; don't display any warning messages.\n"); - fprintf(stderr, " -f Fork into background after authentication.\n"); - fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n"); - - fprintf(stderr, " -c cipher Select encryption algorithm\n"); - fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\n"); - fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n"); - fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n"); - fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n"); - fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname); - fprintf(stderr, " forward them to the other side by connecting to host:port.\n"); - fprintf(stderr, " -D port Enable dynamic application-level port forwarding.\n"); - fprintf(stderr, " -C Enable compression.\n"); - fprintf(stderr, " -N Do not execute a shell or command.\n"); - fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n"); - fprintf(stderr, " -1 Force protocol version 1.\n"); - fprintf(stderr, " -2 Force protocol version 2.\n"); - fprintf(stderr, " -4 Use IPv4 only.\n"); - fprintf(stderr, " -6 Use IPv6 only.\n"); - fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n"); - fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n"); - fprintf(stderr, " -b addr Local IP address.\n"); + fprintf(stderr, +"usage: ssh [-1246AaCfghkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" +" [-D port] [-e escape_char] [-F configfile] [-i identity_file]\n" +" [-L port:host:hostport] [-l login_name] [-m mac_spec] [-o option]\n" +" [-p port] [-R port:host:hostport] [-S ctl] [user@]hostname [command]\n" + ); exit(1); } 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. @@ -200,7 +175,7 @@ int i, opt, exit_status; u_short fwd_port, fwd_host_port; char sfwd_port[6], sfwd_host_port[6]; - char *p, *cp, buf[256]; + char *p, *cp, *line, buf[256]; struct stat st; struct passwd *pw; int dummy; @@ -255,7 +230,7 @@ again: while ((opt = getopt(ac, av, - "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:NPR:TVX")) != -1) { + "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNPR:S:TVXY")) != -1) { switch (opt) { case '1': options.protocol = SSH_PROTO_1; @@ -282,6 +257,10 @@ 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; @@ -295,7 +274,7 @@ options.forward_agent = 1; break; case 'k': - /* ignored for backward compatibility */ + options.gss_deleg_creds = 0; break; case 'i': if (stat(optarg, &st) < 0) { @@ -333,12 +312,8 @@ } /* fallthrough */ case 'V': - fprintf(stderr, - "%s, SSH protocols %d.%d/%d.%d, %s\n", - SSH_VERSION, - PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1, - PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, - SSLeay_version(SSLEAY_VERSION)); + fprintf(stderr, "%s, %s\n", + SSH_VERSION, SSLeay_version(SSLEAY_VERSION)); if (opt == 'V') exit(0); break; @@ -364,7 +339,7 @@ if (ciphers_valid(optarg)) { /* SSH2 only */ options.ciphers = xstrdup(optarg); - options.cipher = SSH_CIPHER_ILLEGAL; + options.cipher = SSH_CIPHER_INVALID; } else { /* SSH1 only */ options.cipher = cipher_number(optarg); @@ -391,6 +366,10 @@ exit(1); } break; + case 'M': + options.control_master = + (options.control_master >= 1) ? 2 : 1; + break; case 'p': options.port = a2port(optarg); if (options.port == 0) { @@ -450,13 +429,20 @@ break; case 'o': dummy = 1; + line = xstrdup(optarg); if (process_config_line(&options, host ? host : "", - optarg, "command-line", 0, &dummy) != 0) + line, "command-line", 0, &dummy) != 0) exit(1); + 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; @@ -551,16 +537,17 @@ * file if the user specifies a config file on the command line. */ if (config != NULL) { - if (!read_config_file(config, host, &options)) + 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); + (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); + (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, + &options, 0); } /* Fill configuration defaults. */ @@ -588,8 +575,15 @@ strcmp(options.proxy_command, "none") == 0) options.proxy_command = NULL; + if (options.control_path != NULL) { + options.control_path = tilde_expand_filename( + options.control_path, original_real_uid); + } + if (options.control_path != NULL && options.control_master == 0) + control_client(options.control_path); /* This doesn't return */ + /* Open a connection to the remote host. */ - if (ssh_connect(host, &hostaddr, options.port, + if (ssh_connect(host, &hostaddr, options.port, options.address_family, options.connection_attempts, original_effective_uid == 0 && options.use_privileged_port, options.proxy_command) != 0) @@ -696,8 +690,11 @@ 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 + * 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) @@ -706,19 +703,25 @@ return exit_status; } +#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" + static void x11_get_proto(char **_proto, char **_data) { + char cmd[1024]; char line[512]; + char xdisplay[512]; static char proto[512], data[512]; FILE *f; - int got_data = 0, i; - char *display; + int got_data = 0, generated = 0, do_unlink = 0, i; + char *display, *xauthdir, *xauthfile; struct stat st; + xauthdir = xauthfile = NULL; *_proto = proto; *_data = data; proto[0] = data[0] = '\0'; + if (!options.xauth_location || (stat(options.xauth_location, &st) == -1)) { debug("No xauth program."); @@ -727,28 +730,59 @@ debug("x11_get_proto: DISPLAY not set"); return; } - /* Try to get Xauthority information for the display. */ - if (strncmp(display, "localhost:", 10) == 0) - /* - * Handle FamilyLocal case where $DISPLAY does - * not match an authorization entry. For this we - * just try "xauth list unix:displaynum.screennum". - * XXX: "localhost" match to determine FamilyLocal - * is not perfect. - */ - snprintf(line, sizeof line, "%s list unix:%s 2>" - _PATH_DEVNULL, options.xauth_location, display+10); - else - snprintf(line, sizeof line, "%s list %.200s 2>" - _PATH_DEVNULL, options.xauth_location, display); - debug2("x11_get_proto: %s", line); - f = popen(line, "r"); + /* + * Handle FamilyLocal case where $DISPLAY does + * not match an authorization entry. For this we + * just try "xauth list unix:displaynum.screennum". + * XXX: "localhost" match to determine FamilyLocal + * is not perfect. + */ + if (strncmp(display, "localhost:", 10) == 0) { + snprintf(xdisplay, sizeof(xdisplay), "unix:%s", + display + 10); + display = xdisplay; + } + if (options.forward_x11_trusted == 0) { + xauthdir = xmalloc(MAXPATHLEN); + xauthfile = xmalloc(MAXPATHLEN); + strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); + if (mkdtemp(xauthdir) != NULL) { + do_unlink = 1; + snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", + xauthdir); + snprintf(cmd, sizeof(cmd), + "%s -f %s generate %s " SSH_X11_PROTO + " untrusted timeout 1200 2>" _PATH_DEVNULL, + options.xauth_location, xauthfile, display); + debug2("x11_get_proto: %s", cmd); + if (system(cmd) == 0) + generated = 1; + } + } + snprintf(cmd, sizeof(cmd), + "%s %s%s list %s . 2>" _PATH_DEVNULL, + options.xauth_location, + generated ? "-f " : "" , + generated ? xauthfile : "", + display); + debug2("x11_get_proto: %s", cmd); + f = popen(cmd, "r"); if (f && fgets(line, sizeof(line), f) && sscanf(line, "%*s %511s %511s", proto, data) == 2) got_data = 1; if (f) pclose(f); } + + if (do_unlink) { + unlink(xauthfile); + rmdir(xauthdir); + } + if (xauthdir) + xfree(xauthdir); + if (xauthfile) + xfree(xauthfile); + /* * If we didn't get authentication data, just make up some * data. The forwarding code will check the validity of the @@ -758,15 +792,17 @@ * for the local connection. */ if (!got_data) { - u_int32_t rand = 0; + u_int32_t rnd = 0; - logit("Warning: No xauth data; using fake authentication data for X11 forwarding."); - strlcpy(proto, "MIT-MAGIC-COOKIE-1", sizeof proto); + logit("Warning: No xauth data; " + "using fake authentication data for X11 forwarding."); + strlcpy(proto, SSH_X11_PROTO, sizeof proto); for (i = 0; i < 16; i++) { if (i % 4 == 0) - rand = arc4random(); - snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", rand & 0xff); - rand >>= 8; + rnd = arc4random(); + snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", + rnd & 0xff); + rnd >>= 8; } } } @@ -953,7 +989,7 @@ } static void -client_subsystem_reply(int type, u_int32_t seq, void *ctxt) +ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt) { int id, len; @@ -968,16 +1004,13 @@ } void -client_global_request_reply(int type, u_int32_t seq, void *ctxt) +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) { - debug("client_global_request_reply: too many replies %d > %d", - i, options.num_remote_forwards); + 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].port, @@ -988,40 +1021,52 @@ options.remote_forwards[i].port); } -/* request pty/x11/agent/tcpfwd/shell for channel */ static void -ssh_session2_setup(int id, void *arg) +ssh_control_listener(void) { - int len; - int interactive = 0; - struct termios tio; + struct sockaddr_un addr; + mode_t old_umask; - debug2("ssh_session2_setup: id %d", id); + if (options.control_path == NULL || options.control_master <= 0) + return; - if (tty_flag) { - struct winsize ws; - char *cp; - cp = getenv("TERM"); - if (!cp) - cp = ""; - /* Store window size in the packet. */ - if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) - memset(&ws, 0, sizeof(ws)); + memset(&addr, '\0', sizeof(addr)); + addr.sun_family = AF_UNIX; + addr.sun_len = offsetof(struct sockaddr_un, sun_path) + + strlen(options.control_path) + 1; - channel_request_start(id, "pty-req", 0); - packet_put_cstring(cp); - packet_put_int(ws.ws_col); - packet_put_int(ws.ws_row); - packet_put_int(ws.ws_xpixel); - packet_put_int(ws.ws_ypixel); - tio = get_saved_tio(); - tty_make_modes(/*ignored*/ 0, &tio); - packet_send(); - interactive = 1; - /* XXX wait for reply */ + if (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\n", __func__, strerror(errno)); + + old_umask = umask(0177); + if (bind(control_fd, (struct sockaddr*)&addr, addr.sun_len) == -1) { + control_fd = -1; + if (errno == EINVAL) + fatal("ControlSocket %s already exists", + options.control_path); + else + fatal("%s bind(): %s\n", __func__, strerror(errno)); } - if (options.forward_x11 && - getenv("DISPLAY") != NULL) { + umask(old_umask); + + if (listen(control_fd, 64) == -1) + fatal("%s listen(): %s\n", __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; + + int interactive = tty_flag; + if (options.forward_x11 && getenv("DISPLAY") != NULL) { char *proto, *data; /* Get reasonable local authentication information. */ x11_get_proto(&proto, &data); @@ -1039,27 +1084,8 @@ packet_send(); } - len = buffer_len(&command); - if (len > 0) { - if (len > 900) - len = 900; - if (subsystem_flag) { - debug("Sending subsystem: %.*s", len, (u_char *)buffer_ptr(&command)); - channel_request_start(id, "subsystem", /*want reply*/ 1); - /* register callback for reply */ - /* XXX we assume that client_loop has already been called */ - dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply); - dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply); - } else { - debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); - channel_request_start(id, "exec", 0); - } - packet_put_string(buffer_ptr(&command), buffer_len(&command)); - packet_send(); - } else { - channel_request_start(id, "shell", 0); - packet_send(); - } + client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), + NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply); packet_set_interactive(interactive); } @@ -1105,7 +1131,7 @@ channel_send_open(c->self); if (!no_shell_flag) - channel_register_confirm(c->self, ssh_session2_setup); + channel_register_confirm(c->self, ssh_session2_setup, NULL); return c->self; } @@ -1117,6 +1143,7 @@ /* XXX should be pre-session */ ssh_init_forwarding(); + ssh_control_listener(); if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) id = ssh_session2_open(); @@ -1169,4 +1196,150 @@ 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; + char name[1024], *cp; + + strlcpy(name, env, sizeof(name)); + if ((cp = strchr(name, '=')) == NULL) + return (0); + + *cp = '\0'; + + 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, sock, exitval, num_env; + Buffer m; + char *cp; + extern char **environ; + + memset(&addr, '\0', sizeof(addr)); + addr.sun_family = AF_UNIX; + addr.sun_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.sun_len) == -1) + fatal("Couldn't connect to %s: %s", path, strerror(errno)); + + if ((cp = getenv("TERM")) == NULL) + cp = ""; + + buffer_init(&m); + + /* Get PID of controlee */ + if (ssh_msg_recv(sock, &m) == -1) + fatal("%s: msg_recv", __func__); + if (buffer_get_char(&m) != 0) + fatal("%s: wrong version", __func__); + /* Connection allowed? */ + if (buffer_get_int(&m) != 1) + fatal("Connection to master denied"); + control_server_pid = buffer_get_int(&m); + + buffer_clear(&m); + buffer_put_int(&m, tty_flag); + buffer_put_int(&m, subsystem_flag); + buffer_put_cstring(&m, cp); + + 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, /* version */0, &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) != 0) + fatal("%s: master returned error", __func__); + buffer_free(&m); + + 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); }