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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * Created: Fri Mar 17 17:09:28 1995 ylo | |
6 | * This program is the ssh daemon. It listens for connections from clients, and | |
7 | * performs authentication, executes use commands or shell, and forwards | |
8 | * information to/from the application to the user client over an encrypted | |
9 | * connection. This can also handle forwarding of X11, TCP/IP, and authentication | |
10 | * agent connections. | |
11 | */ | |
8efc0c15 | 12 | |
13 | #include "includes.h" | |
4fe2af09 | 14 | RCSID("$OpenBSD: sshd.c,v 1.94 2000/03/23 22:15:34 markus Exp $"); |
8efc0c15 | 15 | |
16 | #include "xmalloc.h" | |
17 | #include "rsa.h" | |
18 | #include "ssh.h" | |
19 | #include "pty.h" | |
20 | #include "packet.h" | |
21 | #include "buffer.h" | |
22 | #include "cipher.h" | |
23 | #include "mpaux.h" | |
24 | #include "servconf.h" | |
25 | #include "uidswap.h" | |
26 | #include "compat.h" | |
27 | ||
28 | #ifdef LIBWRAP | |
29 | #include <tcpd.h> | |
30 | #include <syslog.h> | |
31 | int allow_severity = LOG_INFO; | |
32 | int deny_severity = LOG_WARNING; | |
33 | #endif /* LIBWRAP */ | |
34 | ||
35 | #ifndef O_NOCTTY | |
36 | #define O_NOCTTY 0 | |
37 | #endif | |
38 | ||
8efc0c15 | 39 | /* Local Xauthority file. */ |
6a17f9c2 | 40 | static char *xauthfile = NULL; |
8efc0c15 | 41 | |
42 | /* Server configuration options. */ | |
43 | ServerOptions options; | |
44 | ||
45 | /* Name of the server configuration file. */ | |
46 | char *config_file_name = SERVER_CONFIG_FILE; | |
47 | ||
48e671d5 | 48 | /* |
49 | * Flag indicating whether IPv4 or IPv6. This can be set on the command line. | |
50 | * Default value is AF_UNSPEC means both IPv4 and IPv6. | |
51 | */ | |
59e76f33 | 52 | #ifdef IPV4_DEFAULT |
53 | int IPv4or6 = AF_INET; | |
54 | #else | |
48e671d5 | 55 | int IPv4or6 = AF_UNSPEC; |
59e76f33 | 56 | #endif |
48e671d5 | 57 | |
5260325f | 58 | /* |
59 | * Debug mode flag. This can be set on the command line. If debug | |
60 | * mode is enabled, extra debugging output will be sent to the system | |
61 | * log, the daemon will not go to background, and will exit after processing | |
62 | * the first connection. | |
63 | */ | |
8efc0c15 | 64 | int debug_flag = 0; |
65 | ||
66 | /* Flag indicating that the daemon is being started from inetd. */ | |
67 | int inetd_flag = 0; | |
68 | ||
6a17f9c2 | 69 | /* debug goes to stderr unless inetd_flag is set */ |
70 | int log_stderr = 0; | |
71 | ||
8efc0c15 | 72 | /* argv[0] without path. */ |
73 | char *av0; | |
74 | ||
75 | /* Saved arguments to main(). */ | |
76 | char **saved_argv; | |
77 | ||
aa3378df | 78 | /* |
48e671d5 | 79 | * The sockets that the server is listening; this is used in the SIGHUP |
80 | * signal handler. | |
aa3378df | 81 | */ |
48e671d5 | 82 | #define MAX_LISTEN_SOCKS 16 |
83 | int listen_socks[MAX_LISTEN_SOCKS]; | |
84 | int num_listen_socks = 0; | |
8efc0c15 | 85 | |
aa3378df | 86 | /* |
87 | * the client's version string, passed by sshd2 in compat mode. if != NULL, | |
88 | * sshd will skip the version-number exchange | |
89 | */ | |
5260325f | 90 | char *client_version_string = NULL; |
91 | ||
92 | /* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ | |
8efc0c15 | 93 | int no_port_forwarding_flag = 0; |
94 | int no_agent_forwarding_flag = 0; | |
95 | int no_x11_forwarding_flag = 0; | |
96 | int no_pty_flag = 0; | |
5260325f | 97 | |
98 | /* RSA authentication "command=" option. */ | |
99 | char *forced_command = NULL; | |
100 | ||
101 | /* RSA authentication "environment=" options. */ | |
102 | struct envstring *custom_environment = NULL; | |
8efc0c15 | 103 | |
104 | /* Session id for the current session. */ | |
105 | unsigned char session_id[16]; | |
106 | ||
aa3378df | 107 | /* |
108 | * Any really sensitive data in the application is contained in this | |
109 | * structure. The idea is that this structure could be locked into memory so | |
110 | * that the pages do not get written into swap. However, there are some | |
111 | * problems. The private key contains BIGNUMs, and we do not (in principle) | |
112 | * have access to the internals of them, and locking just the structure is | |
113 | * not very useful. Currently, memory locking is not implemented. | |
114 | */ | |
5260325f | 115 | struct { |
116 | RSA *private_key; /* Private part of server key. */ | |
117 | RSA *host_key; /* Private part of host key. */ | |
8efc0c15 | 118 | } sensitive_data; |
119 | ||
aa3378df | 120 | /* |
121 | * Flag indicating whether the current session key has been used. This flag | |
122 | * is set whenever the key is used, and cleared when the key is regenerated. | |
123 | */ | |
8efc0c15 | 124 | int key_used = 0; |
125 | ||
126 | /* This is set to true when SIGHUP is received. */ | |
127 | int received_sighup = 0; | |
128 | ||
129 | /* Public side of the server key. This value is regenerated regularly with | |
130 | the private key. */ | |
131 | RSA *public_key; | |
132 | ||
133 | /* Prototypes for various functions defined later in this file. */ | |
7b2ea3a1 | 134 | void do_ssh_kex(); |
135 | void do_authentication(); | |
5260325f | 136 | void do_authloop(struct passwd * pw); |
e7c0f9d5 | 137 | void do_fake_authloop(char *user); |
5260325f | 138 | void do_authenticated(struct passwd * pw); |
139 | void do_exec_pty(const char *command, int ptyfd, int ttyfd, | |
140 | const char *ttyname, struct passwd * pw, const char *term, | |
141 | const char *display, const char *auth_proto, | |
142 | const char *auth_data); | |
143 | void do_exec_no_pty(const char *command, struct passwd * pw, | |
144 | const char *display, const char *auth_proto, | |
145 | const char *auth_data); | |
146 | void do_child(const char *command, struct passwd * pw, const char *term, | |
8efc0c15 | 147 | const char *display, const char *auth_proto, |
148 | const char *auth_data, const char *ttyname); | |
e7c0f9d5 | 149 | |
c8d54615 | 150 | /* |
151 | * Remove local Xauthority file. | |
152 | */ | |
153 | void | |
154 | xauthfile_cleanup_proc(void *ignore) | |
155 | { | |
156 | debug("xauthfile_cleanup_proc called"); | |
157 | ||
158 | if (xauthfile != NULL) { | |
159 | char *p; | |
160 | unlink(xauthfile); | |
161 | p = strrchr(xauthfile, '/'); | |
162 | if (p != NULL) { | |
163 | *p = '\0'; | |
164 | rmdir(xauthfile); | |
165 | } | |
166 | xfree(xauthfile); | |
167 | xauthfile = NULL; | |
168 | } | |
169 | } | |
170 | ||
48e671d5 | 171 | /* |
172 | * Close all listening sockets | |
173 | */ | |
174 | void | |
175 | close_listen_socks(void) | |
176 | { | |
177 | int i; | |
178 | for (i = 0; i < num_listen_socks; i++) | |
179 | close(listen_socks[i]); | |
180 | num_listen_socks = -1; | |
181 | } | |
182 | ||
5260325f | 183 | /* |
184 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; | |
185 | * the effect is to reread the configuration file (and to regenerate | |
186 | * the server key). | |
187 | */ | |
188 | void | |
189 | sighup_handler(int sig) | |
8efc0c15 | 190 | { |
5260325f | 191 | received_sighup = 1; |
192 | signal(SIGHUP, sighup_handler); | |
8efc0c15 | 193 | } |
194 | ||
5260325f | 195 | /* |
196 | * Called from the main program after receiving SIGHUP. | |
197 | * Restarts the server. | |
198 | */ | |
199 | void | |
200 | sighup_restart() | |
8efc0c15 | 201 | { |
5260325f | 202 | log("Received SIGHUP; restarting."); |
48e671d5 | 203 | close_listen_socks(); |
5260325f | 204 | execv(saved_argv[0], saved_argv); |
205 | log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno)); | |
206 | exit(1); | |
8efc0c15 | 207 | } |
208 | ||
5260325f | 209 | /* |
210 | * Generic signal handler for terminating signals in the master daemon. | |
211 | * These close the listen socket; not closing it seems to cause "Address | |
212 | * already in use" problems on some machines, which is inconvenient. | |
213 | */ | |
214 | void | |
215 | sigterm_handler(int sig) | |
8efc0c15 | 216 | { |
5260325f | 217 | log("Received signal %d; terminating.", sig); |
48e671d5 | 218 | close_listen_socks(); |
5260325f | 219 | exit(255); |
8efc0c15 | 220 | } |
221 | ||
5260325f | 222 | /* |
223 | * SIGCHLD handler. This is called whenever a child dies. This will then | |
224 | * reap any zombies left by exited c. | |
225 | */ | |
226 | void | |
227 | main_sigchld_handler(int sig) | |
8efc0c15 | 228 | { |
5260325f | 229 | int save_errno = errno; |
230 | int status; | |
5ad13cd7 | 231 | |
5260325f | 232 | while (waitpid(-1, &status, WNOHANG) > 0) |
233 | ; | |
5ad13cd7 | 234 | |
5260325f | 235 | signal(SIGCHLD, main_sigchld_handler); |
236 | errno = save_errno; | |
8efc0c15 | 237 | } |
238 | ||
5260325f | 239 | /* |
240 | * Signal handler for the alarm after the login grace period has expired. | |
241 | */ | |
242 | void | |
243 | grace_alarm_handler(int sig) | |
8efc0c15 | 244 | { |
5260325f | 245 | /* Close the connection. */ |
246 | packet_close(); | |
8efc0c15 | 247 | |
5260325f | 248 | /* Log error and exit. */ |
249 | fatal("Timeout before authentication for %s.", get_remote_ipaddr()); | |
250 | } | |
8efc0c15 | 251 | |
5260325f | 252 | /* |
253 | * convert ssh auth msg type into description | |
254 | */ | |
255 | char * | |
256 | get_authname(int type) | |
8efc0c15 | 257 | { |
c8d54615 | 258 | static char buf[1024]; |
5260325f | 259 | switch (type) { |
260 | case SSH_CMSG_AUTH_PASSWORD: | |
261 | return "password"; | |
262 | case SSH_CMSG_AUTH_RSA: | |
263 | return "rsa"; | |
264 | case SSH_CMSG_AUTH_RHOSTS_RSA: | |
265 | return "rhosts-rsa"; | |
266 | case SSH_CMSG_AUTH_RHOSTS: | |
267 | return "rhosts"; | |
268 | #ifdef KRB4 | |
269 | case SSH_CMSG_AUTH_KERBEROS: | |
270 | return "kerberos"; | |
271 | #endif | |
272 | #ifdef SKEY | |
273 | case SSH_CMSG_AUTH_TIS_RESPONSE: | |
274 | return "s/key"; | |
275 | #endif | |
276 | } | |
c8d54615 | 277 | snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); |
278 | return buf; | |
8efc0c15 | 279 | } |
280 | ||
5260325f | 281 | /* |
282 | * Signal handler for the key regeneration alarm. Note that this | |
283 | * alarm only occurs in the daemon waiting for connections, and it does not | |
284 | * do anything with the private key or random state before forking. | |
285 | * Thus there should be no concurrency control/asynchronous execution | |
286 | * problems. | |
287 | */ | |
288 | void | |
289 | key_regeneration_alarm(int sig) | |
290 | { | |
291 | int save_errno = errno; | |
292 | ||
293 | /* Check if we should generate a new key. */ | |
294 | if (key_used) { | |
295 | /* This should really be done in the background. */ | |
296 | log("Generating new %d bit RSA key.", options.server_key_bits); | |
297 | ||
298 | if (sensitive_data.private_key != NULL) | |
299 | RSA_free(sensitive_data.private_key); | |
300 | sensitive_data.private_key = RSA_new(); | |
301 | ||
302 | if (public_key != NULL) | |
303 | RSA_free(public_key); | |
304 | public_key = RSA_new(); | |
305 | ||
306 | rsa_generate_key(sensitive_data.private_key, public_key, | |
307 | options.server_key_bits); | |
308 | arc4random_stir(); | |
309 | key_used = 0; | |
310 | log("RSA key generation complete."); | |
311 | } | |
312 | /* Reschedule the alarm. */ | |
313 | signal(SIGALRM, key_regeneration_alarm); | |
314 | alarm(options.key_regeneration_time); | |
315 | errno = save_errno; | |
316 | } | |
8efc0c15 | 317 | |
5260325f | 318 | /* |
319 | * Main program for the daemon. | |
320 | */ | |
8efc0c15 | 321 | int |
322 | main(int ac, char **av) | |
323 | { | |
5260325f | 324 | extern char *optarg; |
325 | extern int optind; | |
48e671d5 | 326 | int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, pid, on = 1; |
327 | socklen_t fromlen; | |
5260325f | 328 | int remote_major, remote_minor; |
329 | int silentrsa = 0; | |
48e671d5 | 330 | fd_set *fdset; |
331 | struct sockaddr_storage from; | |
5260325f | 332 | char buf[100]; /* Must not be larger than remote_version. */ |
333 | char remote_version[100]; /* Must be at least as big as buf. */ | |
334 | const char *remote_ip; | |
335 | int remote_port; | |
336 | char *comment; | |
337 | FILE *f; | |
338 | struct linger linger; | |
48e671d5 | 339 | struct addrinfo *ai; |
340 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
341 | int listen_sock, maxfd; | |
5260325f | 342 | |
343 | /* Save argv[0]. */ | |
344 | saved_argv = av; | |
345 | if (strchr(av[0], '/')) | |
346 | av0 = strrchr(av[0], '/') + 1; | |
347 | else | |
348 | av0 = av[0]; | |
349 | ||
350 | /* Initialize configuration options to their default values. */ | |
351 | initialize_server_options(&options); | |
352 | ||
353 | /* Parse command-line arguments. */ | |
48e671d5 | 354 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:diqQ46")) != EOF) { |
5260325f | 355 | switch (opt) { |
48e671d5 | 356 | case '4': |
357 | IPv4or6 = AF_INET; | |
358 | break; | |
359 | case '6': | |
360 | IPv4or6 = AF_INET6; | |
361 | break; | |
5260325f | 362 | case 'f': |
363 | config_file_name = optarg; | |
364 | break; | |
365 | case 'd': | |
366 | debug_flag = 1; | |
367 | options.log_level = SYSLOG_LEVEL_DEBUG; | |
368 | break; | |
369 | case 'i': | |
370 | inetd_flag = 1; | |
371 | break; | |
372 | case 'Q': | |
373 | silentrsa = 1; | |
374 | break; | |
375 | case 'q': | |
376 | options.log_level = SYSLOG_LEVEL_QUIET; | |
377 | break; | |
378 | case 'b': | |
379 | options.server_key_bits = atoi(optarg); | |
380 | break; | |
381 | case 'p': | |
48e671d5 | 382 | options.ports_from_cmdline = 1; |
383 | if (options.num_ports >= MAX_PORTS) | |
384 | fatal("too many ports.\n"); | |
385 | options.ports[options.num_ports++] = atoi(optarg); | |
5260325f | 386 | break; |
387 | case 'g': | |
388 | options.login_grace_time = atoi(optarg); | |
389 | break; | |
390 | case 'k': | |
391 | options.key_regeneration_time = atoi(optarg); | |
392 | break; | |
393 | case 'h': | |
394 | options.host_key_file = optarg; | |
395 | break; | |
396 | case 'V': | |
397 | client_version_string = optarg; | |
398 | /* only makes sense with inetd_flag, i.e. no listen() */ | |
399 | inetd_flag = 1; | |
400 | break; | |
401 | case '?': | |
402 | default: | |
403 | fprintf(stderr, "sshd version %s\n", SSH_VERSION); | |
404 | fprintf(stderr, "Usage: %s [options]\n", av0); | |
405 | fprintf(stderr, "Options:\n"); | |
aa3378df | 406 | fprintf(stderr, " -f file Configuration file (default %s)\n", SERVER_CONFIG_FILE); |
5260325f | 407 | fprintf(stderr, " -d Debugging mode\n"); |
408 | fprintf(stderr, " -i Started from inetd\n"); | |
409 | fprintf(stderr, " -q Quiet (no logging)\n"); | |
410 | fprintf(stderr, " -p port Listen on the specified port (default: 22)\n"); | |
411 | fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n"); | |
412 | fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n"); | |
413 | fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n"); | |
414 | fprintf(stderr, " -h file File from which to read host key (default: %s)\n", | |
48e671d5 | 415 | HOST_KEY_FILE); |
416 | fprintf(stderr, " -4 Use IPv4 only\n"); | |
417 | fprintf(stderr, " -6 Use IPv6 only\n"); | |
5260325f | 418 | exit(1); |
419 | } | |
420 | } | |
421 | ||
48e671d5 | 422 | /* |
423 | * Force logging to stderr until we have loaded the private host | |
424 | * key (unless started from inetd) | |
425 | */ | |
426 | log_init(av0, | |
427 | options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, | |
428 | options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility, | |
429 | !inetd_flag); | |
430 | ||
5260325f | 431 | /* check if RSA support exists */ |
432 | if (rsa_alive() == 0) { | |
433 | if (silentrsa == 0) | |
434 | printf("sshd: no RSA support in libssl and libcrypto -- exiting. See ssl(8)\n"); | |
435 | log("no RSA support in libssl and libcrypto -- exiting. See ssl(8)"); | |
436 | exit(1); | |
437 | } | |
438 | /* Read server configuration options from the configuration file. */ | |
439 | read_server_config(&options, config_file_name); | |
440 | ||
441 | /* Fill in default values for those options not explicitly set. */ | |
442 | fill_default_server_options(&options); | |
443 | ||
444 | /* Check certain values for sanity. */ | |
445 | if (options.server_key_bits < 512 || | |
446 | options.server_key_bits > 32768) { | |
447 | fprintf(stderr, "Bad server key size.\n"); | |
448 | exit(1); | |
449 | } | |
5260325f | 450 | /* Check that there are no remaining arguments. */ |
451 | if (optind < ac) { | |
452 | fprintf(stderr, "Extra argument %s.\n", av[optind]); | |
453 | exit(1); | |
8efc0c15 | 454 | } |
5260325f | 455 | |
456 | debug("sshd version %.100s", SSH_VERSION); | |
457 | ||
458 | sensitive_data.host_key = RSA_new(); | |
459 | errno = 0; | |
460 | /* Load the host key. It must have empty passphrase. */ | |
461 | if (!load_private_key(options.host_key_file, "", | |
462 | sensitive_data.host_key, &comment)) { | |
463 | error("Could not load host key: %.200s: %.100s", | |
464 | options.host_key_file, strerror(errno)); | |
465 | exit(1); | |
466 | } | |
467 | xfree(comment); | |
468 | ||
469 | /* Initialize the log (it is reinitialized below in case we | |
470 | forked). */ | |
471 | if (debug_flag && !inetd_flag) | |
472 | log_stderr = 1; | |
473 | log_init(av0, options.log_level, options.log_facility, log_stderr); | |
474 | ||
475 | /* If not in debugging mode, and not started from inetd, | |
476 | disconnect from the controlling terminal, and fork. The | |
477 | original process exits. */ | |
478 | if (!debug_flag && !inetd_flag) { | |
8efc0c15 | 479 | #ifdef TIOCNOTTY |
5260325f | 480 | int fd; |
8efc0c15 | 481 | #endif /* TIOCNOTTY */ |
5260325f | 482 | if (daemon(0, 0) < 0) |
483 | fatal("daemon() failed: %.200s", strerror(errno)); | |
484 | ||
485 | /* Disconnect from the controlling tty. */ | |
8efc0c15 | 486 | #ifdef TIOCNOTTY |
5260325f | 487 | fd = open("/dev/tty", O_RDWR | O_NOCTTY); |
488 | if (fd >= 0) { | |
489 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
490 | close(fd); | |
491 | } | |
8efc0c15 | 492 | #endif /* TIOCNOTTY */ |
8efc0c15 | 493 | } |
5260325f | 494 | /* Reinitialize the log (because of the fork above). */ |
495 | log_init(av0, options.log_level, options.log_facility, log_stderr); | |
496 | ||
497 | /* Check that server and host key lengths differ sufficiently. | |
498 | This is necessary to make double encryption work with rsaref. | |
499 | Oh, I hate software patents. I dont know if this can go? Niels */ | |
500 | if (options.server_key_bits > | |
501 | BN_num_bits(sensitive_data.host_key->n) - SSH_KEY_BITS_RESERVED && | |
502 | options.server_key_bits < | |
503 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) { | |
504 | options.server_key_bits = | |
505 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED; | |
506 | debug("Forcing server key to %d bits to make it differ from host key.", | |
507 | options.server_key_bits); | |
8efc0c15 | 508 | } |
5260325f | 509 | /* Do not display messages to stdout in RSA code. */ |
510 | rsa_set_verbose(0); | |
511 | ||
512 | /* Initialize the random number generator. */ | |
513 | arc4random_stir(); | |
514 | ||
515 | /* Chdir to the root directory so that the current disk can be | |
516 | unmounted if desired. */ | |
517 | chdir("/"); | |
518 | ||
5260325f | 519 | /* Start listening for a socket, unless started from inetd. */ |
520 | if (inetd_flag) { | |
521 | int s1, s2; | |
522 | s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */ | |
523 | s2 = dup(s1); | |
524 | sock_in = dup(0); | |
525 | sock_out = dup(1); | |
526 | /* We intentionally do not close the descriptors 0, 1, and 2 | |
527 | as our code for setting the descriptors won\'t work | |
528 | if ttyfd happens to be one of those. */ | |
529 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); | |
530 | ||
531 | public_key = RSA_new(); | |
532 | sensitive_data.private_key = RSA_new(); | |
533 | ||
534 | log("Generating %d bit RSA key.", options.server_key_bits); | |
535 | rsa_generate_key(sensitive_data.private_key, public_key, | |
536 | options.server_key_bits); | |
537 | arc4random_stir(); | |
538 | log("RSA key generation complete."); | |
539 | } else { | |
48e671d5 | 540 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
541 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
542 | continue; | |
543 | if (num_listen_socks >= MAX_LISTEN_SOCKS) | |
544 | fatal("Too many listen sockets. " | |
545 | "Enlarge MAX_LISTEN_SOCKS"); | |
546 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
547 | ntop, sizeof(ntop), strport, sizeof(strport), | |
548 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
549 | error("getnameinfo failed"); | |
550 | continue; | |
551 | } | |
552 | /* Create socket for listening. */ | |
553 | listen_sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
554 | if (listen_sock < 0) { | |
555 | /* kernel may not support ipv6 */ | |
556 | verbose("socket: %.100s", strerror(errno)); | |
557 | continue; | |
558 | } | |
559 | if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) { | |
560 | error("listen_sock O_NONBLOCK: %s", strerror(errno)); | |
561 | close(listen_sock); | |
562 | continue; | |
563 | } | |
564 | /* | |
565 | * Set socket options. We try to make the port | |
566 | * reusable and have it close as fast as possible | |
567 | * without waiting in unnecessary wait states on | |
568 | * close. | |
569 | */ | |
570 | setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, | |
571 | (void *) &on, sizeof(on)); | |
572 | linger.l_onoff = 1; | |
573 | linger.l_linger = 5; | |
574 | setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, | |
575 | (void *) &linger, sizeof(linger)); | |
576 | ||
577 | debug("Bind to port %s on %s.", strport, ntop); | |
578 | ||
579 | /* Bind the socket to the desired port. */ | |
16218745 | 580 | if ((bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) && |
581 | (!ai->ai_next)) { | |
48e671d5 | 582 | error("Bind to port %s on %s failed: %.200s.", |
583 | strport, ntop, strerror(errno)); | |
584 | close(listen_sock); | |
585 | continue; | |
586 | } | |
587 | listen_socks[num_listen_socks] = listen_sock; | |
588 | num_listen_socks++; | |
589 | ||
590 | /* Start listening on the port. */ | |
591 | log("Server listening on %s port %s.", ntop, strport); | |
592 | if (listen(listen_sock, 5) < 0) | |
593 | fatal("listen: %.100s", strerror(errno)); | |
594 | ||
5260325f | 595 | } |
48e671d5 | 596 | freeaddrinfo(options.listen_addrs); |
597 | ||
598 | if (!num_listen_socks) | |
599 | fatal("Cannot bind any address."); | |
600 | ||
5260325f | 601 | if (!debug_flag) { |
aa3378df | 602 | /* |
603 | * Record our pid in /etc/sshd_pid to make it easier | |
604 | * to kill the correct sshd. We don\'t want to do | |
605 | * this before the bind above because the bind will | |
606 | * fail if there already is a daemon, and this will | |
607 | * overwrite any old pid in the file. | |
608 | */ | |
5260325f | 609 | f = fopen(SSH_DAEMON_PID_FILE, "w"); |
610 | if (f) { | |
611 | fprintf(f, "%u\n", (unsigned int) getpid()); | |
612 | fclose(f); | |
613 | } | |
8efc0c15 | 614 | } |
8efc0c15 | 615 | |
5260325f | 616 | public_key = RSA_new(); |
617 | sensitive_data.private_key = RSA_new(); | |
618 | ||
619 | log("Generating %d bit RSA key.", options.server_key_bits); | |
620 | rsa_generate_key(sensitive_data.private_key, public_key, | |
621 | options.server_key_bits); | |
622 | arc4random_stir(); | |
623 | log("RSA key generation complete."); | |
624 | ||
625 | /* Schedule server key regeneration alarm. */ | |
626 | signal(SIGALRM, key_regeneration_alarm); | |
627 | alarm(options.key_regeneration_time); | |
628 | ||
629 | /* Arrange to restart on SIGHUP. The handler needs listen_sock. */ | |
630 | signal(SIGHUP, sighup_handler); | |
631 | signal(SIGTERM, sigterm_handler); | |
632 | signal(SIGQUIT, sigterm_handler); | |
633 | ||
634 | /* Arrange SIGCHLD to be caught. */ | |
635 | signal(SIGCHLD, main_sigchld_handler); | |
636 | ||
48e671d5 | 637 | /* setup fd set for listen */ |
638 | maxfd = 0; | |
639 | for (i = 0; i < num_listen_socks; i++) | |
640 | if (listen_socks[i] > maxfd) | |
641 | maxfd = listen_socks[i]; | |
642 | fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask); | |
643 | fdset = (fd_set *)xmalloc(fdsetsz); | |
644 | ||
aa3378df | 645 | /* |
646 | * Stay listening for connections until the system crashes or | |
647 | * the daemon is killed with a signal. | |
648 | */ | |
5260325f | 649 | for (;;) { |
650 | if (received_sighup) | |
651 | sighup_restart(); | |
48e671d5 | 652 | /* Wait in select until there is a connection. */ |
653 | memset(fdset, 0, fdsetsz); | |
654 | for (i = 0; i < num_listen_socks; i++) | |
655 | FD_SET(listen_socks[i], fdset); | |
656 | if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) { | |
657 | if (errno != EINTR) | |
658 | error("select: %.100s", strerror(errno)); | |
2d86a6cc | 659 | continue; |
48e671d5 | 660 | } |
661 | for (i = 0; i < num_listen_socks; i++) { | |
662 | if (!FD_ISSET(listen_socks[i], fdset)) | |
5260325f | 663 | continue; |
48e671d5 | 664 | fromlen = sizeof(from); |
665 | newsock = accept(listen_socks[i], (struct sockaddr *)&from, | |
666 | &fromlen); | |
667 | if (newsock < 0) { | |
668 | if (errno != EINTR && errno != EWOULDBLOCK) | |
669 | error("accept: %.100s", strerror(errno)); | |
670 | continue; | |
671 | } | |
672 | if (fcntl(newsock, F_SETFL, 0) < 0) { | |
673 | error("newsock del O_NONBLOCK: %s", strerror(errno)); | |
5260325f | 674 | continue; |
675 | } | |
aa3378df | 676 | /* |
677 | * Got connection. Fork a child to handle it, unless | |
678 | * we are in debugging mode. | |
679 | */ | |
5260325f | 680 | if (debug_flag) { |
aa3378df | 681 | /* |
682 | * In debugging mode. Close the listening | |
683 | * socket, and start processing the | |
684 | * connection without forking. | |
685 | */ | |
5260325f | 686 | debug("Server will not fork when running in debugging mode."); |
48e671d5 | 687 | close_listen_socks(); |
5260325f | 688 | sock_in = newsock; |
689 | sock_out = newsock; | |
690 | pid = getpid(); | |
691 | break; | |
692 | } else { | |
aa3378df | 693 | /* |
694 | * Normal production daemon. Fork, and have | |
695 | * the child process the connection. The | |
696 | * parent continues listening. | |
697 | */ | |
5260325f | 698 | if ((pid = fork()) == 0) { |
aa3378df | 699 | /* |
700 | * Child. Close the listening socket, and start using the | |
701 | * accepted socket. Reinitialize logging (since our pid has | |
702 | * changed). We break out of the loop to handle the connection. | |
703 | */ | |
48e671d5 | 704 | close_listen_socks(); |
5260325f | 705 | sock_in = newsock; |
706 | sock_out = newsock; | |
707 | log_init(av0, options.log_level, options.log_facility, log_stderr); | |
708 | break; | |
709 | } | |
710 | } | |
711 | ||
712 | /* Parent. Stay in the loop. */ | |
713 | if (pid < 0) | |
714 | error("fork: %.100s", strerror(errno)); | |
715 | else | |
716 | debug("Forked child %d.", pid); | |
717 | ||
718 | /* Mark that the key has been used (it was "given" to the child). */ | |
719 | key_used = 1; | |
720 | ||
721 | arc4random_stir(); | |
722 | ||
723 | /* Close the new socket (the child is now taking care of it). */ | |
724 | close(newsock); | |
48e671d5 | 725 | } /* for (i = 0; i < num_listen_socks; i++) */ |
726 | /* child process check (or debug mode) */ | |
727 | if (num_listen_socks < 0) | |
728 | break; | |
5260325f | 729 | } |
730 | } | |
8efc0c15 | 731 | |
5260325f | 732 | /* This is the child processing a new connection. */ |
733 | ||
aa3378df | 734 | /* |
735 | * Disable the key regeneration alarm. We will not regenerate the | |
736 | * key since we are no longer in a position to give it to anyone. We | |
737 | * will not restart on SIGHUP since it no longer makes sense. | |
738 | */ | |
5260325f | 739 | alarm(0); |
740 | signal(SIGALRM, SIG_DFL); | |
741 | signal(SIGHUP, SIG_DFL); | |
742 | signal(SIGTERM, SIG_DFL); | |
743 | signal(SIGQUIT, SIG_DFL); | |
744 | signal(SIGCHLD, SIG_DFL); | |
745 | ||
aa3378df | 746 | /* |
747 | * Set socket options for the connection. We want the socket to | |
748 | * close as fast as possible without waiting for anything. If the | |
749 | * connection is not a socket, these will do nothing. | |
750 | */ | |
751 | /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */ | |
5260325f | 752 | linger.l_onoff = 1; |
753 | linger.l_linger = 5; | |
754 | setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger)); | |
755 | ||
aa3378df | 756 | /* |
757 | * Register our connection. This turns encryption off because we do | |
758 | * not have a key. | |
759 | */ | |
5260325f | 760 | packet_set_connection(sock_in, sock_out); |
761 | ||
762 | remote_port = get_remote_port(); | |
763 | remote_ip = get_remote_ipaddr(); | |
764 | ||
765 | /* Check whether logins are denied from this host. */ | |
766 | #ifdef LIBWRAP | |
48e671d5 | 767 | /* XXX LIBWRAP noes not know about IPv6 */ |
5260325f | 768 | { |
769 | struct request_info req; | |
8efc0c15 | 770 | |
5260325f | 771 | request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL); |
772 | fromhost(&req); | |
8efc0c15 | 773 | |
5260325f | 774 | if (!hosts_access(&req)) { |
775 | close(sock_in); | |
776 | close(sock_out); | |
777 | refuse(&req); | |
778 | } | |
48e671d5 | 779 | /*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */ |
8efc0c15 | 780 | } |
48e671d5 | 781 | #endif /* LIBWRAP */ |
5260325f | 782 | /* Log the connection. */ |
783 | verbose("Connection from %.500s port %d", remote_ip, remote_port); | |
8efc0c15 | 784 | |
aa3378df | 785 | /* |
786 | * We don\'t want to listen forever unless the other side | |
787 | * successfully authenticates itself. So we set up an alarm which is | |
788 | * cleared after successful authentication. A limit of zero | |
789 | * indicates no limit. Note that we don\'t set the alarm in debugging | |
790 | * mode; it is just annoying to have the server exit just when you | |
791 | * are about to discover the bug. | |
792 | */ | |
5260325f | 793 | signal(SIGALRM, grace_alarm_handler); |
794 | if (!debug_flag) | |
795 | alarm(options.login_grace_time); | |
796 | ||
797 | if (client_version_string != NULL) { | |
798 | /* we are exec'ed by sshd2, so skip exchange of protocol version */ | |
799 | strlcpy(buf, client_version_string, sizeof(buf)); | |
800 | } else { | |
801 | /* Send our protocol version identification. */ | |
802 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
803 | PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION); | |
9bc5ddfe | 804 | if (atomicio(write, sock_out, buf, strlen(buf)) != strlen(buf)) { |
805 | log("Could not write ident string to %s.", remote_ip); | |
806 | fatal_cleanup(); | |
807 | } | |
5260325f | 808 | |
809 | /* Read other side\'s version identification. */ | |
810 | for (i = 0; i < sizeof(buf) - 1; i++) { | |
9bc5ddfe | 811 | if (read(sock_in, &buf[i], 1) != 1) { |
812 | log("Did not receive ident string from %s.", remote_ip); | |
813 | fatal_cleanup(); | |
814 | } | |
5260325f | 815 | if (buf[i] == '\r') { |
816 | buf[i] = '\n'; | |
817 | buf[i + 1] = 0; | |
818 | break; | |
819 | } | |
820 | if (buf[i] == '\n') { | |
821 | /* buf[i] == '\n' */ | |
822 | buf[i + 1] = 0; | |
823 | break; | |
824 | } | |
825 | } | |
826 | buf[sizeof(buf) - 1] = 0; | |
8efc0c15 | 827 | } |
5260325f | 828 | |
aa3378df | 829 | /* |
830 | * Check that the versions match. In future this might accept | |
831 | * several versions and set appropriate flags to handle them. | |
832 | */ | |
5260325f | 833 | if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", &remote_major, &remote_minor, |
a408af76 | 834 | remote_version) != 3) { |
835 | char *s = "Protocol mismatch.\n"; | |
836 | ||
837 | (void) atomicio(write, sock_out, s, strlen(s)); | |
5260325f | 838 | close(sock_in); |
839 | close(sock_out); | |
9bc5ddfe | 840 | log("Bad protocol version identification '%.100s' from %s", |
841 | buf, remote_ip); | |
842 | fatal_cleanup(); | |
5260325f | 843 | } |
844 | debug("Client protocol version %d.%d; client software version %.100s", | |
845 | remote_major, remote_minor, remote_version); | |
846 | if (remote_major != PROTOCOL_MAJOR) { | |
a408af76 | 847 | char *s = "Protocol major versions differ.\n"; |
848 | ||
849 | (void) atomicio(write, sock_out, s, strlen(s)); | |
5260325f | 850 | close(sock_in); |
851 | close(sock_out); | |
9bc5ddfe | 852 | log("Protocol major versions differ for %s: %d vs. %d", |
853 | remote_ip, PROTOCOL_MAJOR, remote_major); | |
854 | fatal_cleanup(); | |
8efc0c15 | 855 | } |
5260325f | 856 | /* Check that the client has sufficiently high software version. */ |
857 | if (remote_major == 1 && remote_minor < 3) | |
858 | packet_disconnect("Your ssh version is too old and is no longer supported. Please install a newer version."); | |
859 | ||
860 | if (remote_major == 1 && remote_minor == 3) { | |
7b2ea3a1 | 861 | /* note that this disables agent-forwarding */ |
5260325f | 862 | enable_compat13(); |
5260325f | 863 | } |
aa3378df | 864 | /* |
865 | * Check that the connection comes from a privileged port. Rhosts- | |
866 | * and Rhosts-RSA-Authentication only make sense from priviledged | |
867 | * programs. Of course, if the intruder has root access on his local | |
868 | * machine, he can connect from any port. So do not use these | |
869 | * authentication methods from machines that you do not trust. | |
870 | */ | |
5260325f | 871 | if (remote_port >= IPPORT_RESERVED || |
872 | remote_port < IPPORT_RESERVED / 2) { | |
873 | options.rhosts_authentication = 0; | |
874 | options.rhosts_rsa_authentication = 0; | |
875 | } | |
48e671d5 | 876 | #ifdef KRB4 |
877 | if (!packet_connection_is_ipv4() && | |
878 | options.kerberos_authentication) { | |
879 | debug("Kerberos Authentication disabled, only available for IPv4."); | |
880 | options.kerberos_authentication = 0; | |
881 | } | |
882 | #endif /* KRB4 */ | |
883 | ||
5260325f | 884 | packet_set_nonblocking(); |
885 | ||
7b2ea3a1 | 886 | /* perform the key exchange */ |
887 | do_ssh_kex(); | |
888 | ||
889 | /* authenticate user and start session */ | |
890 | do_authentication(); | |
8efc0c15 | 891 | |
892 | #ifdef KRB4 | |
5260325f | 893 | /* Cleanup user's ticket cache file. */ |
894 | if (options.kerberos_ticket_cleanup) | |
895 | (void) dest_tkt(); | |
8efc0c15 | 896 | #endif /* KRB4 */ |
897 | ||
5260325f | 898 | /* Cleanup user's local Xauthority file. */ |
899 | if (xauthfile) | |
c8d54615 | 900 | xauthfile_cleanup_proc(NULL); |
8efc0c15 | 901 | |
5260325f | 902 | /* The connection has been terminated. */ |
903 | verbose("Closing connection to %.100s", remote_ip); | |
8efc0c15 | 904 | |
d94aa2ae | 905 | #ifdef USE_PAM |
a5c9cd31 | 906 | finish_pam(); |
d94aa2ae | 907 | #endif /* USE_PAM */ |
8efc0c15 | 908 | |
5260325f | 909 | packet_close(); |
910 | exit(0); | |
911 | } | |
8efc0c15 | 912 | |
5260325f | 913 | /* |
7b2ea3a1 | 914 | * SSH1 key exchange |
5260325f | 915 | */ |
e7c0f9d5 | 916 | void |
7b2ea3a1 | 917 | do_ssh_kex() |
8efc0c15 | 918 | { |
5260325f | 919 | int i, len; |
7b2ea3a1 | 920 | int plen, slen; |
5260325f | 921 | BIGNUM *session_key_int; |
922 | unsigned char session_key[SSH_SESSION_KEY_LENGTH]; | |
7b2ea3a1 | 923 | unsigned char cookie[8]; |
5260325f | 924 | unsigned int cipher_type, auth_mask, protocol_flags; |
5260325f | 925 | u_int32_t rand = 0; |
926 | ||
aa3378df | 927 | /* |
928 | * Generate check bytes that the client must send back in the user | |
929 | * packet in order for it to be accepted; this is used to defy ip | |
930 | * spoofing attacks. Note that this only works against somebody | |
931 | * doing IP spoofing from a remote machine; any machine on the local | |
932 | * network can still see outgoing packets and catch the random | |
933 | * cookie. This only affects rhosts authentication, and this is one | |
934 | * of the reasons why it is inherently insecure. | |
935 | */ | |
5260325f | 936 | for (i = 0; i < 8; i++) { |
937 | if (i % 4 == 0) | |
938 | rand = arc4random(); | |
7b2ea3a1 | 939 | cookie[i] = rand & 0xff; |
5260325f | 940 | rand >>= 8; |
941 | } | |
942 | ||
aa3378df | 943 | /* |
944 | * Send our public key. We include in the packet 64 bits of random | |
945 | * data that must be matched in the reply in order to prevent IP | |
946 | * spoofing. | |
947 | */ | |
5260325f | 948 | packet_start(SSH_SMSG_PUBLIC_KEY); |
949 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 950 | packet_put_char(cookie[i]); |
5260325f | 951 | |
952 | /* Store our public server RSA key. */ | |
953 | packet_put_int(BN_num_bits(public_key->n)); | |
954 | packet_put_bignum(public_key->e); | |
955 | packet_put_bignum(public_key->n); | |
956 | ||
957 | /* Store our public host RSA key. */ | |
958 | packet_put_int(BN_num_bits(sensitive_data.host_key->n)); | |
959 | packet_put_bignum(sensitive_data.host_key->e); | |
960 | packet_put_bignum(sensitive_data.host_key->n); | |
961 | ||
962 | /* Put protocol flags. */ | |
963 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | |
964 | ||
965 | /* Declare which ciphers we support. */ | |
966 | packet_put_int(cipher_mask()); | |
967 | ||
968 | /* Declare supported authentication types. */ | |
969 | auth_mask = 0; | |
970 | if (options.rhosts_authentication) | |
971 | auth_mask |= 1 << SSH_AUTH_RHOSTS; | |
972 | if (options.rhosts_rsa_authentication) | |
973 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; | |
974 | if (options.rsa_authentication) | |
975 | auth_mask |= 1 << SSH_AUTH_RSA; | |
8efc0c15 | 976 | #ifdef KRB4 |
5260325f | 977 | if (options.kerberos_authentication) |
978 | auth_mask |= 1 << SSH_AUTH_KERBEROS; | |
8efc0c15 | 979 | #endif |
980 | #ifdef AFS | |
5260325f | 981 | if (options.kerberos_tgt_passing) |
982 | auth_mask |= 1 << SSH_PASS_KERBEROS_TGT; | |
983 | if (options.afs_token_passing) | |
984 | auth_mask |= 1 << SSH_PASS_AFS_TOKEN; | |
8efc0c15 | 985 | #endif |
5260325f | 986 | #ifdef SKEY |
987 | if (options.skey_authentication == 1) | |
988 | auth_mask |= 1 << SSH_AUTH_TIS; | |
989 | #endif | |
990 | if (options.password_authentication) | |
991 | auth_mask |= 1 << SSH_AUTH_PASSWORD; | |
992 | packet_put_int(auth_mask); | |
993 | ||
994 | /* Send the packet and wait for it to be sent. */ | |
995 | packet_send(); | |
996 | packet_write_wait(); | |
997 | ||
998 | debug("Sent %d bit public key and %d bit host key.", | |
999 | BN_num_bits(public_key->n), BN_num_bits(sensitive_data.host_key->n)); | |
1000 | ||
1001 | /* Read clients reply (cipher type and session key). */ | |
1002 | packet_read_expect(&plen, SSH_CMSG_SESSION_KEY); | |
1003 | ||
2d86a6cc | 1004 | /* Get cipher type and check whether we accept this. */ |
5260325f | 1005 | cipher_type = packet_get_char(); |
1006 | ||
2d86a6cc | 1007 | if (!(cipher_mask() & (1 << cipher_type))) |
1008 | packet_disconnect("Warning: client selects unsupported cipher."); | |
1009 | ||
5260325f | 1010 | /* Get check bytes from the packet. These must match those we |
1011 | sent earlier with the public key packet. */ | |
1012 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1013 | if (cookie[i] != packet_get_char()) |
5260325f | 1014 | packet_disconnect("IP Spoofing check bytes do not match."); |
1015 | ||
1016 | debug("Encryption type: %.200s", cipher_name(cipher_type)); | |
1017 | ||
1018 | /* Get the encrypted integer. */ | |
1019 | session_key_int = BN_new(); | |
1020 | packet_get_bignum(session_key_int, &slen); | |
1021 | ||
5260325f | 1022 | protocol_flags = packet_get_int(); |
1023 | packet_set_protocol_flags(protocol_flags); | |
1024 | ||
1025 | packet_integrity_check(plen, 1 + 8 + slen + 4, SSH_CMSG_SESSION_KEY); | |
1026 | ||
aa3378df | 1027 | /* |
1028 | * Decrypt it using our private server key and private host key (key | |
1029 | * with larger modulus first). | |
1030 | */ | |
5260325f | 1031 | if (BN_cmp(sensitive_data.private_key->n, sensitive_data.host_key->n) > 0) { |
1032 | /* Private key has bigger modulus. */ | |
1033 | if (BN_num_bits(sensitive_data.private_key->n) < | |
1034 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) { | |
1035 | fatal("do_connection: %s: private_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", | |
1036 | get_remote_ipaddr(), | |
1037 | BN_num_bits(sensitive_data.private_key->n), | |
1038 | BN_num_bits(sensitive_data.host_key->n), | |
1039 | SSH_KEY_BITS_RESERVED); | |
1040 | } | |
1041 | rsa_private_decrypt(session_key_int, session_key_int, | |
1042 | sensitive_data.private_key); | |
1043 | rsa_private_decrypt(session_key_int, session_key_int, | |
1044 | sensitive_data.host_key); | |
1045 | } else { | |
1046 | /* Host key has bigger modulus (or they are equal). */ | |
1047 | if (BN_num_bits(sensitive_data.host_key->n) < | |
1048 | BN_num_bits(sensitive_data.private_key->n) + SSH_KEY_BITS_RESERVED) { | |
1049 | fatal("do_connection: %s: host_key %d < private_key %d + SSH_KEY_BITS_RESERVED %d", | |
1050 | get_remote_ipaddr(), | |
1051 | BN_num_bits(sensitive_data.host_key->n), | |
1052 | BN_num_bits(sensitive_data.private_key->n), | |
1053 | SSH_KEY_BITS_RESERVED); | |
1054 | } | |
1055 | rsa_private_decrypt(session_key_int, session_key_int, | |
1056 | sensitive_data.host_key); | |
1057 | rsa_private_decrypt(session_key_int, session_key_int, | |
1058 | sensitive_data.private_key); | |
1059 | } | |
1060 | ||
7b2ea3a1 | 1061 | compute_session_id(session_id, cookie, |
5260325f | 1062 | sensitive_data.host_key->n, |
1063 | sensitive_data.private_key->n); | |
1064 | ||
7b2ea3a1 | 1065 | /* Destroy the private and public keys. They will no longer be needed. */ |
1066 | RSA_free(public_key); | |
1067 | RSA_free(sensitive_data.private_key); | |
1068 | RSA_free(sensitive_data.host_key); | |
1069 | ||
aa3378df | 1070 | /* |
1071 | * Extract session key from the decrypted integer. The key is in the | |
1072 | * least significant 256 bits of the integer; the first byte of the | |
1073 | * key is in the highest bits. | |
1074 | */ | |
5260325f | 1075 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); |
1076 | len = BN_num_bytes(session_key_int); | |
1077 | if (len < 0 || len > sizeof(session_key)) | |
1078 | fatal("do_connection: bad len from %s: session_key_int %d > sizeof(session_key) %d", | |
1079 | get_remote_ipaddr(), | |
1080 | len, sizeof(session_key)); | |
1081 | memset(session_key, 0, sizeof(session_key)); | |
1082 | BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len); | |
1083 | ||
7b2ea3a1 | 1084 | /* Destroy the decrypted integer. It is no longer needed. */ |
1085 | BN_clear_free(session_key_int); | |
1086 | ||
5260325f | 1087 | /* Xor the first 16 bytes of the session key with the session id. */ |
1088 | for (i = 0; i < 16; i++) | |
1089 | session_key[i] ^= session_id[i]; | |
1090 | ||
5260325f | 1091 | /* Set the session key. From this on all communications will be encrypted. */ |
1092 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); | |
1093 | ||
1094 | /* Destroy our copy of the session key. It is no longer needed. */ | |
1095 | memset(session_key, 0, sizeof(session_key)); | |
1096 | ||
1097 | debug("Received session key; encryption turned on."); | |
1098 | ||
1099 | /* Send an acknowledgement packet. Note that this packet is sent encrypted. */ | |
1100 | packet_start(SSH_SMSG_SUCCESS); | |
1101 | packet_send(); | |
1102 | packet_write_wait(); | |
5260325f | 1103 | } |
8efc0c15 | 1104 | |
7b2ea3a1 | 1105 | |
5260325f | 1106 | /* |
1107 | * Check if the user is allowed to log in via ssh. If user is listed in | |
1108 | * DenyUsers or user's primary group is listed in DenyGroups, false will | |
1109 | * be returned. If AllowUsers isn't empty and user isn't listed there, or | |
1110 | * if AllowGroups isn't empty and user isn't listed there, false will be | |
c8d54615 | 1111 | * returned. |
1112 | * If the user's shell is not executable, false will be returned. | |
1113 | * Otherwise true is returned. | |
5260325f | 1114 | */ |
8efc0c15 | 1115 | static int |
5260325f | 1116 | allowed_user(struct passwd * pw) |
8efc0c15 | 1117 | { |
c8d54615 | 1118 | struct stat st; |
5260325f | 1119 | struct group *grp; |
1120 | int i; | |
4c40f834 | 1121 | #ifdef WITH_AIXAUTHENTICATE |
1122 | char *loginmsg; | |
1123 | #endif /* WITH_AIXAUTHENTICATE */ | |
5260325f | 1124 | |
1125 | /* Shouldn't be called if pw is NULL, but better safe than sorry... */ | |
1126 | if (!pw) | |
1127 | return 0; | |
1128 | ||
c8d54615 | 1129 | /* deny if shell does not exists or is not executable */ |
1130 | if (stat(pw->pw_shell, &st) != 0) | |
1131 | return 0; | |
1132 | if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)))) | |
1133 | return 0; | |
5260325f | 1134 | |
1135 | /* Return false if user is listed in DenyUsers */ | |
1136 | if (options.num_deny_users > 0) { | |
1137 | if (!pw->pw_name) | |
1138 | return 0; | |
1139 | for (i = 0; i < options.num_deny_users; i++) | |
1140 | if (match_pattern(pw->pw_name, options.deny_users[i])) | |
1141 | return 0; | |
1142 | } | |
aa3378df | 1143 | /* Return false if AllowUsers isn't empty and user isn't listed there */ |
5260325f | 1144 | if (options.num_allow_users > 0) { |
1145 | if (!pw->pw_name) | |
1146 | return 0; | |
1147 | for (i = 0; i < options.num_allow_users; i++) | |
1148 | if (match_pattern(pw->pw_name, options.allow_users[i])) | |
1149 | break; | |
1150 | /* i < options.num_allow_users iff we break for loop */ | |
1151 | if (i >= options.num_allow_users) | |
1152 | return 0; | |
1153 | } | |
1154 | /* Get the primary group name if we need it. Return false if it fails */ | |
1155 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { | |
1156 | grp = getgrgid(pw->pw_gid); | |
1157 | if (!grp) | |
1158 | return 0; | |
1159 | ||
1160 | /* Return false if user's group is listed in DenyGroups */ | |
1161 | if (options.num_deny_groups > 0) { | |
1162 | if (!grp->gr_name) | |
1163 | return 0; | |
1164 | for (i = 0; i < options.num_deny_groups; i++) | |
1165 | if (match_pattern(grp->gr_name, options.deny_groups[i])) | |
1166 | return 0; | |
1167 | } | |
aa3378df | 1168 | /* |
1169 | * Return false if AllowGroups isn't empty and user's group | |
1170 | * isn't listed there | |
1171 | */ | |
5260325f | 1172 | if (options.num_allow_groups > 0) { |
1173 | if (!grp->gr_name) | |
1174 | return 0; | |
1175 | for (i = 0; i < options.num_allow_groups; i++) | |
1176 | if (match_pattern(grp->gr_name, options.allow_groups[i])) | |
1177 | break; | |
1178 | /* i < options.num_allow_groups iff we break for | |
1179 | loop */ | |
1180 | if (i >= options.num_allow_groups) | |
1181 | return 0; | |
1182 | } | |
1183 | } | |
4c40f834 | 1184 | |
1185 | #ifdef WITH_AIXAUTHENTICATE | |
1186 | if (loginrestrictions(pw->pw_name,S_LOGIN,NULL,&loginmsg) != 0) | |
1187 | return 0; | |
1188 | #endif /* WITH_AIXAUTHENTICATE */ | |
1189 | ||
5260325f | 1190 | /* We found no reason not to let this user try to log on... */ |
1191 | return 1; | |
8efc0c15 | 1192 | } |
1193 | ||
5260325f | 1194 | /* |
1195 | * Performs authentication of an incoming connection. Session key has already | |
7b2ea3a1 | 1196 | * been exchanged and encryption is enabled. |
5260325f | 1197 | */ |
8efc0c15 | 1198 | void |
7b2ea3a1 | 1199 | do_authentication() |
8efc0c15 | 1200 | { |
5260325f | 1201 | struct passwd *pw, pwcopy; |
610cd5c6 | 1202 | int plen; |
1203 | unsigned int ulen; | |
7b2ea3a1 | 1204 | char *user; |
1205 | ||
1206 | /* Get the name of the user that we wish to log in as. */ | |
1207 | packet_read_expect(&plen, SSH_CMSG_USER); | |
1208 | ||
1209 | /* Get the user name. */ | |
1210 | user = packet_get_string(&ulen); | |
1211 | packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); | |
1212 | ||
1213 | setproctitle("%s", user); | |
e7c0f9d5 | 1214 | |
4c40f834 | 1215 | #ifdef WITH_AIXAUTHENTICATE |
1216 | char *loginmsg; | |
1217 | #endif /* WITH_AIXAUTHENTICATE */ | |
1218 | ||
8efc0c15 | 1219 | #ifdef AFS |
5260325f | 1220 | /* If machine has AFS, set process authentication group. */ |
1221 | if (k_hasafs()) { | |
1222 | k_setpag(); | |
1223 | k_unlog(); | |
1224 | } | |
8efc0c15 | 1225 | #endif /* AFS */ |
5260325f | 1226 | |
1227 | /* Verify that the user is a valid user. */ | |
1228 | pw = getpwnam(user); | |
1229 | if (!pw || !allowed_user(pw)) | |
1230 | do_fake_authloop(user); | |
c8d54615 | 1231 | xfree(user); |
5260325f | 1232 | |
1233 | /* Take a copy of the returned structure. */ | |
1234 | memset(&pwcopy, 0, sizeof(pwcopy)); | |
1235 | pwcopy.pw_name = xstrdup(pw->pw_name); | |
1236 | pwcopy.pw_passwd = xstrdup(pw->pw_passwd); | |
1237 | pwcopy.pw_uid = pw->pw_uid; | |
1238 | pwcopy.pw_gid = pw->pw_gid; | |
1239 | pwcopy.pw_dir = xstrdup(pw->pw_dir); | |
1240 | pwcopy.pw_shell = xstrdup(pw->pw_shell); | |
1241 | pw = &pwcopy; | |
8efc0c15 | 1242 | |
d94aa2ae | 1243 | #ifdef USE_PAM |
a5c9cd31 | 1244 | start_pam(pw); |
5aecb327 | 1245 | #endif |
0183ea1c | 1246 | |
aa3378df | 1247 | /* |
1248 | * If we are not running as root, the user must have the same uid as | |
1249 | * the server. | |
1250 | */ | |
5260325f | 1251 | if (getuid() != 0 && pw->pw_uid != getuid()) |
1252 | packet_disconnect("Cannot change user when server not running as root."); | |
8efc0c15 | 1253 | |
c8d54615 | 1254 | debug("Attempting authentication for %.100s.", pw->pw_name); |
8efc0c15 | 1255 | |
5260325f | 1256 | /* If the user has no password, accept authentication immediately. */ |
1257 | if (options.password_authentication && | |
8efc0c15 | 1258 | #ifdef KRB4 |
5260325f | 1259 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && |
8efc0c15 | 1260 | #endif /* KRB4 */ |
d94aa2ae | 1261 | #ifdef USE_PAM |
a5c9cd31 | 1262 | auth_pam_password(pw, "")) { |
d94aa2ae | 1263 | #else /* USE_PAM */ |
5260325f | 1264 | auth_password(pw, "")) { |
d94aa2ae | 1265 | #endif /* USE_PAM */ |
5260325f | 1266 | /* Authentication with empty password succeeded. */ |
1267 | log("Login for user %s from %.100s, accepted without authentication.", | |
1268 | pw->pw_name, get_remote_ipaddr()); | |
1269 | } else { | |
1270 | /* Loop until the user has been authenticated or the | |
1271 | connection is closed, do_authloop() returns only if | |
1272 | authentication is successfull */ | |
1273 | do_authloop(pw); | |
1274 | } | |
1275 | ||
5260325f | 1276 | /* The user has been authenticated and accepted. */ |
4c40f834 | 1277 | #ifdef WITH_AIXAUTHENTICATE |
1278 | loginsuccess(user,get_canonical_hostname(),"ssh",&loginmsg); | |
1279 | #endif /* WITH_AIXAUTHENTICATE */ | |
5260325f | 1280 | packet_start(SSH_SMSG_SUCCESS); |
1281 | packet_send(); | |
1282 | packet_write_wait(); | |
1283 | ||
1284 | /* Perform session preparation. */ | |
1285 | do_authenticated(pw); | |
e7c0f9d5 | 1286 | } |
8efc0c15 | 1287 | |
5260325f | 1288 | #define AUTH_FAIL_MAX 6 |
1289 | #define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2) | |
1290 | #define AUTH_FAIL_MSG "Too many authentication failures for %.100s" | |
e7c0f9d5 | 1291 | |
5260325f | 1292 | /* |
1293 | * read packets and try to authenticate local user *pw. | |
1294 | * return if authentication is successfull | |
1295 | */ | |
e7c0f9d5 | 1296 | void |
5260325f | 1297 | do_authloop(struct passwd * pw) |
e7c0f9d5 | 1298 | { |
5260325f | 1299 | int attempt = 0; |
1300 | unsigned int bits; | |
4fe2af09 | 1301 | RSA *client_host_key; |
5260325f | 1302 | BIGNUM *n; |
1303 | char *client_user = NULL, *password = NULL; | |
1304 | char user[1024]; | |
610cd5c6 | 1305 | unsigned int dlen; |
1306 | int plen, nlen, elen; | |
1307 | unsigned int ulen; | |
5260325f | 1308 | int type = 0; |
1309 | void (*authlog) (const char *fmt,...) = verbose; | |
e7c0f9d5 | 1310 | |
5260325f | 1311 | /* Indicate that authentication is needed. */ |
1312 | packet_start(SSH_SMSG_FAILURE); | |
1313 | packet_send(); | |
1314 | packet_write_wait(); | |
e7c0f9d5 | 1315 | |
5260325f | 1316 | for (attempt = 1;; attempt++) { |
1317 | int authenticated = 0; | |
1318 | strlcpy(user, "", sizeof user); | |
e7c0f9d5 | 1319 | |
5260325f | 1320 | /* Get a packet from the client. */ |
1321 | type = packet_read(&plen); | |
1322 | ||
1323 | /* Process the packet. */ | |
1324 | switch (type) { | |
e7c0f9d5 | 1325 | #ifdef AFS |
5260325f | 1326 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
1327 | if (!options.kerberos_tgt_passing) { | |
1328 | /* packet_get_all(); */ | |
1329 | verbose("Kerberos tgt passing disabled."); | |
1330 | break; | |
1331 | } else { | |
1332 | /* Accept Kerberos tgt. */ | |
1333 | char *tgt = packet_get_string(&dlen); | |
1334 | packet_integrity_check(plen, 4 + dlen, type); | |
1335 | if (!auth_kerberos_tgt(pw, tgt)) | |
1336 | verbose("Kerberos tgt REFUSED for %s", pw->pw_name); | |
1337 | xfree(tgt); | |
1338 | } | |
1339 | continue; | |
1340 | ||
1341 | case SSH_CMSG_HAVE_AFS_TOKEN: | |
1342 | if (!options.afs_token_passing || !k_hasafs()) { | |
1343 | /* packet_get_all(); */ | |
1344 | verbose("AFS token passing disabled."); | |
1345 | break; | |
1346 | } else { | |
1347 | /* Accept AFS token. */ | |
1348 | char *token_string = packet_get_string(&dlen); | |
1349 | packet_integrity_check(plen, 4 + dlen, type); | |
1350 | if (!auth_afs_token(pw, token_string)) | |
1351 | verbose("AFS token REFUSED for %s", pw->pw_name); | |
1352 | xfree(token_string); | |
1353 | } | |
1354 | continue; | |
8efc0c15 | 1355 | #endif /* AFS */ |
e7c0f9d5 | 1356 | #ifdef KRB4 |
5260325f | 1357 | case SSH_CMSG_AUTH_KERBEROS: |
1358 | if (!options.kerberos_authentication) { | |
1359 | /* packet_get_all(); */ | |
1360 | verbose("Kerberos authentication disabled."); | |
1361 | break; | |
1362 | } else { | |
1363 | /* Try Kerberos v4 authentication. */ | |
1364 | KTEXT_ST auth; | |
1365 | char *tkt_user = NULL; | |
1366 | char *kdata = packet_get_string((unsigned int *) &auth.length); | |
1367 | packet_integrity_check(plen, 4 + auth.length, type); | |
1368 | ||
1369 | if (auth.length < MAX_KTXT_LEN) | |
1370 | memcpy(auth.dat, kdata, auth.length); | |
1371 | xfree(kdata); | |
1372 | ||
1373 | authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); | |
1374 | ||
1375 | if (authenticated) { | |
1376 | snprintf(user, sizeof user, " tktuser %s", tkt_user); | |
1377 | xfree(tkt_user); | |
1378 | } | |
1379 | } | |
1380 | break; | |
e7c0f9d5 | 1381 | #endif /* KRB4 */ |
5260325f | 1382 | |
1383 | case SSH_CMSG_AUTH_RHOSTS: | |
1384 | if (!options.rhosts_authentication) { | |
1385 | verbose("Rhosts authentication disabled."); | |
1386 | break; | |
1387 | } | |
aa3378df | 1388 | /* |
1389 | * Get client user name. Note that we just have to | |
1390 | * trust the client; this is one reason why rhosts | |
1391 | * authentication is insecure. (Another is | |
1392 | * IP-spoofing on a local network.) | |
1393 | */ | |
5260325f | 1394 | client_user = packet_get_string(&ulen); |
1395 | packet_integrity_check(plen, 4 + ulen, type); | |
1396 | ||
1397 | /* Try to authenticate using /etc/hosts.equiv and | |
1398 | .rhosts. */ | |
1399 | authenticated = auth_rhosts(pw, client_user); | |
1400 | ||
1401 | snprintf(user, sizeof user, " ruser %s", client_user); | |
5260325f | 1402 | break; |
1403 | ||
1404 | case SSH_CMSG_AUTH_RHOSTS_RSA: | |
1405 | if (!options.rhosts_rsa_authentication) { | |
1406 | verbose("Rhosts with RSA authentication disabled."); | |
1407 | break; | |
1408 | } | |
aa3378df | 1409 | /* |
1410 | * Get client user name. Note that we just have to | |
1411 | * trust the client; root on the client machine can | |
1412 | * claim to be any user. | |
1413 | */ | |
5260325f | 1414 | client_user = packet_get_string(&ulen); |
1415 | ||
1416 | /* Get the client host key. */ | |
4fe2af09 | 1417 | client_host_key = RSA_new(); |
1418 | if (client_host_key == NULL) | |
1419 | fatal("RSA_new failed"); | |
1420 | client_host_key->e = BN_new(); | |
1421 | client_host_key->n = BN_new(); | |
1422 | if (client_host_key->e == NULL || client_host_key->n == NULL) | |
1423 | fatal("BN_new failed"); | |
5260325f | 1424 | bits = packet_get_int(); |
4fe2af09 | 1425 | packet_get_bignum(client_host_key->e, &elen); |
1426 | packet_get_bignum(client_host_key->n, &nlen); | |
5260325f | 1427 | |
4fe2af09 | 1428 | if (bits != BN_num_bits(client_host_key->n)) |
5260325f | 1429 | error("Warning: keysize mismatch for client_host_key: " |
4fe2af09 | 1430 | "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); |
5260325f | 1431 | packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); |
1432 | ||
4fe2af09 | 1433 | authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); |
1434 | RSA_free(client_host_key); | |
5260325f | 1435 | |
1436 | snprintf(user, sizeof user, " ruser %s", client_user); | |
5260325f | 1437 | break; |
1438 | ||
1439 | case SSH_CMSG_AUTH_RSA: | |
1440 | if (!options.rsa_authentication) { | |
1441 | verbose("RSA authentication disabled."); | |
1442 | break; | |
1443 | } | |
1444 | /* RSA authentication requested. */ | |
1445 | n = BN_new(); | |
1446 | packet_get_bignum(n, &nlen); | |
1447 | packet_integrity_check(plen, nlen, type); | |
1448 | authenticated = auth_rsa(pw, n); | |
1449 | BN_clear_free(n); | |
1450 | break; | |
1451 | ||
1452 | case SSH_CMSG_AUTH_PASSWORD: | |
1453 | if (!options.password_authentication) { | |
1454 | verbose("Password authentication disabled."); | |
1455 | break; | |
1456 | } | |
aa3378df | 1457 | /* |
1458 | * Read user password. It is in plain text, but was | |
1459 | * transmitted over the encrypted channel so it is | |
1460 | * not visible to an outside observer. | |
1461 | */ | |
5260325f | 1462 | password = packet_get_string(&dlen); |
1463 | packet_integrity_check(plen, 4 + dlen, type); | |
1464 | ||
d94aa2ae | 1465 | #ifdef USE_PAM |
5260325f | 1466 | /* Do PAM auth with password */ |
a5c9cd31 | 1467 | authenticated = auth_pam_password(pw, password); |
d94aa2ae | 1468 | #else /* USE_PAM */ |
5260325f | 1469 | /* Try authentication with the password. */ |
1470 | authenticated = auth_password(pw, password); | |
d94aa2ae | 1471 | #endif /* USE_PAM */ |
5260325f | 1472 | memset(password, 0, strlen(password)); |
1473 | xfree(password); | |
1474 | break; | |
5260325f | 1475 | |
1476 | #ifdef SKEY | |
1477 | case SSH_CMSG_AUTH_TIS: | |
1478 | debug("rcvd SSH_CMSG_AUTH_TIS"); | |
1479 | if (options.skey_authentication == 1) { | |
1480 | char *skeyinfo = skey_keyinfo(pw->pw_name); | |
1481 | if (skeyinfo == NULL) { | |
1482 | debug("generating fake skeyinfo for %.100s.", pw->pw_name); | |
1483 | skeyinfo = skey_fake_keyinfo(pw->pw_name); | |
1484 | } | |
1485 | if (skeyinfo != NULL) { | |
aa3378df | 1486 | /* we send our s/key- in tis-challenge messages */ |
5260325f | 1487 | debug("sending challenge '%s'", skeyinfo); |
1488 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); | |
1489 | packet_put_string(skeyinfo, strlen(skeyinfo)); | |
1490 | packet_send(); | |
1491 | packet_write_wait(); | |
1492 | continue; | |
1493 | } | |
1494 | } | |
1495 | break; | |
1496 | case SSH_CMSG_AUTH_TIS_RESPONSE: | |
1497 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); | |
1498 | if (options.skey_authentication == 1) { | |
1499 | char *response = packet_get_string(&dlen); | |
1500 | debug("skey response == '%s'", response); | |
1501 | packet_integrity_check(plen, 4 + dlen, type); | |
1502 | authenticated = (skey_haskey(pw->pw_name) == 0 && | |
1503 | skey_passcheck(pw->pw_name, response) != -1); | |
1504 | xfree(response); | |
1505 | } | |
1506 | break; | |
1507 | #else | |
1508 | case SSH_CMSG_AUTH_TIS: | |
1509 | /* TIS Authentication is unsupported */ | |
1510 | log("TIS authentication unsupported."); | |
1511 | break; | |
1512 | #endif | |
1513 | ||
1514 | default: | |
aa3378df | 1515 | /* |
1516 | * Any unknown messages will be ignored (and failure | |
1517 | * returned) during authentication. | |
1518 | */ | |
5260325f | 1519 | log("Unknown message during authentication: type %d", type); |
1520 | break; | |
1521 | } | |
1522 | ||
43e48848 | 1523 | /* |
1524 | * Check if the user is logging in as root and root logins | |
1525 | * are disallowed. | |
1526 | * Note that root login is allowed for forced commands. | |
1527 | */ | |
1528 | if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) { | |
1529 | if (forced_command) { | |
1530 | log("Root login accepted for forced command."); | |
1531 | } else { | |
1532 | authenticated = 0; | |
1533 | log("ROOT LOGIN REFUSED FROM %.200s", | |
1534 | get_canonical_hostname()); | |
1535 | } | |
1536 | } | |
1537 | ||
5260325f | 1538 | /* Raise logging level */ |
1539 | if (authenticated || | |
1540 | attempt == AUTH_FAIL_LOG || | |
1541 | type == SSH_CMSG_AUTH_PASSWORD) | |
1542 | authlog = log; | |
1543 | ||
1544 | authlog("%s %s for %.200s from %.200s port %d%s", | |
1545 | authenticated ? "Accepted" : "Failed", | |
1546 | get_authname(type), | |
1547 | pw->pw_uid == 0 ? "ROOT" : pw->pw_name, | |
1548 | get_remote_ipaddr(), | |
1549 | get_remote_port(), | |
1550 | user); | |
8efc0c15 | 1551 | |
a5c9cd31 | 1552 | #ifdef USE_PAM |
c8d54615 | 1553 | if (authenticated) { |
4c40f834 | 1554 | if (!do_pam_account(pw->pw_name, client_user)) { |
c8d54615 | 1555 | if (client_user != NULL) { |
a5c9cd31 | 1556 | xfree(client_user); |
c8d54615 | 1557 | client_user = NULL; |
1558 | } | |
a5c9cd31 | 1559 | do_fake_authloop(pw->pw_name); |
1560 | } | |
5260325f | 1561 | return; |
d465f2ca | 1562 | } |
c8d54615 | 1563 | #else /* USE_PAM */ |
1564 | if (authenticated) { | |
1565 | return; | |
1566 | } | |
1567 | #endif /* USE_PAM */ | |
5260325f | 1568 | |
d07d1c58 | 1569 | if (client_user != NULL) { |
a5c9cd31 | 1570 | xfree(client_user); |
d07d1c58 | 1571 | client_user = NULL; |
1572 | } | |
d465f2ca | 1573 | |
a5c9cd31 | 1574 | if (attempt > AUTH_FAIL_MAX) |
5260325f | 1575 | packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); |
1576 | ||
1577 | /* Send a message indicating that the authentication attempt failed. */ | |
1578 | packet_start(SSH_SMSG_FAILURE); | |
1579 | packet_send(); | |
1580 | packet_write_wait(); | |
1581 | } | |
8efc0c15 | 1582 | } |
1583 | ||
5260325f | 1584 | /* |
1585 | * The user does not exist or access is denied, | |
1586 | * but fake indication that authentication is needed. | |
1587 | */ | |
e7c0f9d5 | 1588 | void |
1589 | do_fake_authloop(char *user) | |
0183ea1c | 1590 | { |
5260325f | 1591 | int attempt = 0; |
1592 | ||
1593 | log("Faking authloop for illegal user %.200s from %.200s port %d", | |
1594 | user, | |
1595 | get_remote_ipaddr(), | |
1596 | get_remote_port()); | |
1597 | ||
1598 | /* Indicate that authentication is needed. */ | |
1599 | packet_start(SSH_SMSG_FAILURE); | |
1600 | packet_send(); | |
1601 | packet_write_wait(); | |
1602 | ||
aa3378df | 1603 | /* |
1604 | * Keep reading packets, and always respond with a failure. This is | |
1605 | * to avoid disclosing whether such a user really exists. | |
1606 | */ | |
5260325f | 1607 | for (attempt = 1;; attempt++) { |
aa3378df | 1608 | /* Read a packet. This will not return if the client disconnects. */ |
5260325f | 1609 | int plen; |
a5c9cd31 | 1610 | #ifndef SKEY |
1611 | (void)packet_read(&plen); | |
1612 | #else /* SKEY */ | |
5260325f | 1613 | int type = packet_read(&plen); |
610cd5c6 | 1614 | unsigned int dlen; |
5260325f | 1615 | char *password, *skeyinfo; |
95f1eccc | 1616 | /* Try to send a fake s/key challenge. */ |
1617 | if (options.skey_authentication == 1 && | |
5260325f | 1618 | (skeyinfo = skey_fake_keyinfo(user)) != NULL) { |
c8d54615 | 1619 | password = NULL; |
95f1eccc | 1620 | if (type == SSH_CMSG_AUTH_TIS) { |
1621 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); | |
1622 | packet_put_string(skeyinfo, strlen(skeyinfo)); | |
1623 | packet_send(); | |
1624 | packet_write_wait(); | |
1625 | continue; | |
1626 | } else if (type == SSH_CMSG_AUTH_PASSWORD && | |
1627 | options.password_authentication && | |
1628 | (password = packet_get_string(&dlen)) != NULL && | |
1629 | dlen == 5 && | |
1630 | strncasecmp(password, "s/key", 5) == 0 ) { | |
1631 | packet_send_debug(skeyinfo); | |
1632 | } | |
c8d54615 | 1633 | if (password != NULL) |
1634 | xfree(password); | |
5260325f | 1635 | } |
e7c0f9d5 | 1636 | #endif |
5260325f | 1637 | if (attempt > AUTH_FAIL_MAX) |
1638 | packet_disconnect(AUTH_FAIL_MSG, user); | |
1639 | ||
aa3378df | 1640 | /* |
1641 | * Send failure. This should be indistinguishable from a | |
1642 | * failed authentication. | |
1643 | */ | |
5260325f | 1644 | packet_start(SSH_SMSG_FAILURE); |
1645 | packet_send(); | |
1646 | packet_write_wait(); | |
4c40f834 | 1647 | #ifdef WITH_AIXAUTHENTICATE |
1648 | if (strncmp(get_authname(type),"password", | |
1649 | strlen(get_authname(type))) == 0) | |
1650 | loginfailed(pw->pw_name,get_canonical_hostname(),"ssh"); | |
1651 | #endif /* WITH_AIXAUTHENTICATE */ | |
5260325f | 1652 | } |
1653 | /* NOTREACHED */ | |
1654 | abort(); | |
0183ea1c | 1655 | } |
1656 | ||
817175bc | 1657 | struct pty_cleanup_context { |
1658 | const char *ttyname; | |
1659 | int pid; | |
1660 | }; | |
1661 | ||
1662 | /* | |
1663 | * Function to perform cleanup if we get aborted abnormally (e.g., due to a | |
1664 | * dropped connection). | |
1665 | */ | |
1666 | void | |
1667 | pty_cleanup_proc(void *context) | |
1668 | { | |
1669 | struct pty_cleanup_context *cu = context; | |
1670 | ||
1671 | debug("pty_cleanup_proc called"); | |
1672 | ||
1673 | /* Record that the user has logged out. */ | |
1674 | record_logout(cu->pid, cu->ttyname); | |
1675 | ||
1676 | /* Release the pseudo-tty. */ | |
1677 | pty_release(cu->ttyname); | |
1678 | } | |
1679 | ||
1680 | /* simple cleanup: chown tty slave back to root */ | |
1681 | static void | |
1682 | pty_release_proc(void *tty) | |
1683 | { | |
1684 | char *ttyname = tty; | |
1685 | pty_release(ttyname); | |
1686 | } | |
1687 | ||
5260325f | 1688 | /* |
1689 | * Prepares for an interactive session. This is called after the user has | |
1690 | * been successfully authenticated. During this message exchange, pseudo | |
1691 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings | |
1692 | * are requested, etc. | |
1693 | */ | |
1694 | void | |
1695 | do_authenticated(struct passwd * pw) | |
8efc0c15 | 1696 | { |
5260325f | 1697 | int type; |
1698 | int compression_level = 0, enable_compression_after_reply = 0; | |
c8d54615 | 1699 | int have_pty = 0, ptyfd = -1, ttyfd = -1; |
5260325f | 1700 | int row, col, xpixel, ypixel, screen; |
1701 | char ttyname[64]; | |
817175bc | 1702 | char *command, *term = NULL, *display = NULL, *proto = NULL, *data = NULL; |
610cd5c6 | 1703 | int plen; |
1704 | unsigned int dlen; | |
5260325f | 1705 | int n_bytes; |
1706 | ||
aa3378df | 1707 | /* |
1708 | * Cancel the alarm we set to limit the time taken for | |
1709 | * authentication. | |
1710 | */ | |
5260325f | 1711 | alarm(0); |
1712 | ||
aa3378df | 1713 | /* |
1714 | * Inform the channel mechanism that we are the server side and that | |
1715 | * the client may request to connect to any port at all. (The user | |
1716 | * could do it anyway, and we wouldn\'t know what is permitted except | |
1717 | * by the client telling us, so we can equally well trust the client | |
1718 | * not to request anything bogus.) | |
1719 | */ | |
c8d54615 | 1720 | if (!no_port_forwarding_flag) |
1721 | channel_permit_all_opens(); | |
5260325f | 1722 | |
aa3378df | 1723 | /* |
1724 | * We stay in this loop until the client requests to execute a shell | |
1725 | * or a command. | |
1726 | */ | |
5260325f | 1727 | while (1) { |
5260325f | 1728 | |
1729 | /* Get a packet from the client. */ | |
1730 | type = packet_read(&plen); | |
1731 | ||
1732 | /* Process the packet. */ | |
1733 | switch (type) { | |
1734 | case SSH_CMSG_REQUEST_COMPRESSION: | |
1735 | packet_integrity_check(plen, 4, type); | |
1736 | compression_level = packet_get_int(); | |
1737 | if (compression_level < 1 || compression_level > 9) { | |
1738 | packet_send_debug("Received illegal compression level %d.", | |
1739 | compression_level); | |
1740 | goto fail; | |
1741 | } | |
1742 | /* Enable compression after we have responded with SUCCESS. */ | |
1743 | enable_compression_after_reply = 1; | |
1744 | break; | |
1745 | ||
1746 | case SSH_CMSG_REQUEST_PTY: | |
1747 | if (no_pty_flag) { | |
1748 | debug("Allocating a pty not permitted for this authentication."); | |
1749 | goto fail; | |
1750 | } | |
1751 | if (have_pty) | |
1752 | packet_disconnect("Protocol error: you already have a pty."); | |
1753 | ||
1754 | debug("Allocating pty."); | |
1755 | ||
1756 | /* Allocate a pty and open it. */ | |
a408af76 | 1757 | if (!pty_allocate(&ptyfd, &ttyfd, ttyname, |
1758 | sizeof(ttyname))) { | |
5260325f | 1759 | error("Failed to allocate pty."); |
1760 | goto fail; | |
1761 | } | |
817175bc | 1762 | fatal_add_cleanup(pty_release_proc, (void *)ttyname); |
1763 | pty_setowner(pw, ttyname); | |
5260325f | 1764 | |
1765 | /* Get TERM from the packet. Note that the value may be of arbitrary length. */ | |
1766 | term = packet_get_string(&dlen); | |
1767 | packet_integrity_check(dlen, strlen(term), type); | |
817175bc | 1768 | |
5260325f | 1769 | /* Remaining bytes */ |
1770 | n_bytes = plen - (4 + dlen + 4 * 4); | |
1771 | ||
817175bc | 1772 | if (strcmp(term, "") == 0) { |
1773 | xfree(term); | |
5260325f | 1774 | term = NULL; |
817175bc | 1775 | } |
5260325f | 1776 | |
1777 | /* Get window size from the packet. */ | |
1778 | row = packet_get_int(); | |
1779 | col = packet_get_int(); | |
1780 | xpixel = packet_get_int(); | |
1781 | ypixel = packet_get_int(); | |
1782 | pty_change_window_size(ptyfd, row, col, xpixel, ypixel); | |
1783 | ||
1784 | /* Get tty modes from the packet. */ | |
1785 | tty_parse_modes(ttyfd, &n_bytes); | |
1786 | packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); | |
1787 | ||
1788 | /* Indicate that we now have a pty. */ | |
1789 | have_pty = 1; | |
1790 | break; | |
1791 | ||
1792 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
1793 | if (!options.x11_forwarding) { | |
1794 | packet_send_debug("X11 forwarding disabled in server configuration file."); | |
1795 | goto fail; | |
1796 | } | |
8efc0c15 | 1797 | #ifdef XAUTH_PATH |
5260325f | 1798 | if (no_x11_forwarding_flag) { |
1799 | packet_send_debug("X11 forwarding not permitted for this authentication."); | |
1800 | goto fail; | |
1801 | } | |
1802 | debug("Received request for X11 forwarding with auth spoofing."); | |
1803 | if (display) | |
1804 | packet_disconnect("Protocol error: X11 display already set."); | |
1805 | { | |
610cd5c6 | 1806 | unsigned int proto_len, data_len; |
5260325f | 1807 | proto = packet_get_string(&proto_len); |
1808 | data = packet_get_string(&data_len); | |
1809 | packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); | |
1810 | } | |
1811 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) | |
1812 | screen = packet_get_int(); | |
1813 | else | |
1814 | screen = 0; | |
95f1eccc | 1815 | display = x11_create_display_inet(screen, options.x11_display_offset); |
5260325f | 1816 | if (!display) |
1817 | goto fail; | |
1818 | ||
1819 | /* Setup to always have a local .Xauthority. */ | |
1820 | xauthfile = xmalloc(MAXPATHLEN); | |
c8d54615 | 1821 | strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); |
1822 | temporarily_use_uid(pw->pw_uid); | |
1823 | if (mkdtemp(xauthfile) == NULL) { | |
1824 | restore_uid(); | |
1825 | error("private X11 dir: mkdtemp %s failed: %s", | |
1826 | xauthfile, strerror(errno)); | |
5260325f | 1827 | xfree(xauthfile); |
1828 | xauthfile = NULL; | |
c8d54615 | 1829 | goto fail; |
5260325f | 1830 | } |
c8d54615 | 1831 | strlcat(xauthfile, "/cookies", MAXPATHLEN); |
1832 | open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); | |
1833 | restore_uid(); | |
1834 | fatal_add_cleanup(xauthfile_cleanup_proc, NULL); | |
5260325f | 1835 | break; |
8efc0c15 | 1836 | #else /* XAUTH_PATH */ |
5260325f | 1837 | packet_send_debug("No xauth program; cannot forward with spoofing."); |
1838 | goto fail; | |
8efc0c15 | 1839 | #endif /* XAUTH_PATH */ |
1840 | ||
5260325f | 1841 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: |
7b2ea3a1 | 1842 | if (no_agent_forwarding_flag || compat13) { |
5260325f | 1843 | debug("Authentication agent forwarding not permitted for this authentication."); |
1844 | goto fail; | |
1845 | } | |
1846 | debug("Received authentication agent forwarding request."); | |
1847 | auth_input_request_forwarding(pw); | |
1848 | break; | |
1849 | ||
1850 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
1851 | if (no_port_forwarding_flag) { | |
1852 | debug("Port forwarding not permitted for this authentication."); | |
1853 | goto fail; | |
1854 | } | |
1855 | debug("Received TCP/IP port forwarding request."); | |
1856 | channel_input_port_forward_request(pw->pw_uid == 0); | |
1857 | break; | |
1858 | ||
1859 | case SSH_CMSG_MAX_PACKET_SIZE: | |
1860 | if (packet_set_maxsize(packet_get_int()) < 0) | |
1861 | goto fail; | |
1862 | break; | |
1863 | ||
1864 | case SSH_CMSG_EXEC_SHELL: | |
1865 | /* Set interactive/non-interactive mode. */ | |
1866 | packet_set_interactive(have_pty || display != NULL, | |
1867 | options.keepalives); | |
1868 | ||
1869 | if (forced_command != NULL) | |
1870 | goto do_forced_command; | |
1871 | debug("Forking shell."); | |
1872 | packet_integrity_check(plen, 0, type); | |
1873 | if (have_pty) | |
1874 | do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); | |
1875 | else | |
1876 | do_exec_no_pty(NULL, pw, display, proto, data); | |
1877 | return; | |
1878 | ||
1879 | case SSH_CMSG_EXEC_CMD: | |
1880 | /* Set interactive/non-interactive mode. */ | |
1881 | packet_set_interactive(have_pty || display != NULL, | |
1882 | options.keepalives); | |
1883 | ||
1884 | if (forced_command != NULL) | |
1885 | goto do_forced_command; | |
1886 | /* Get command from the packet. */ | |
1887 | { | |
610cd5c6 | 1888 | unsigned int dlen; |
5260325f | 1889 | command = packet_get_string(&dlen); |
1890 | debug("Executing command '%.500s'", command); | |
1891 | packet_integrity_check(plen, 4 + dlen, type); | |
1892 | } | |
1893 | if (have_pty) | |
1894 | do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); | |
1895 | else | |
1896 | do_exec_no_pty(command, pw, display, proto, data); | |
1897 | xfree(command); | |
1898 | return; | |
1899 | ||
1900 | default: | |
aa3378df | 1901 | /* |
1902 | * Any unknown messages in this phase are ignored, | |
1903 | * and a failure message is returned. | |
1904 | */ | |
5260325f | 1905 | log("Unknown packet type received after authentication: %d", type); |
1906 | goto fail; | |
1907 | } | |
8efc0c15 | 1908 | |
5260325f | 1909 | /* The request was successfully processed. */ |
1910 | packet_start(SSH_SMSG_SUCCESS); | |
1911 | packet_send(); | |
1912 | packet_write_wait(); | |
8efc0c15 | 1913 | |
5260325f | 1914 | /* Enable compression now that we have replied if appropriate. */ |
1915 | if (enable_compression_after_reply) { | |
1916 | enable_compression_after_reply = 0; | |
1917 | packet_start_compression(compression_level); | |
1918 | } | |
1919 | continue; | |
8efc0c15 | 1920 | |
5260325f | 1921 | fail: |
1922 | /* The request failed. */ | |
1923 | packet_start(SSH_SMSG_FAILURE); | |
1924 | packet_send(); | |
1925 | packet_write_wait(); | |
1926 | continue; | |
8efc0c15 | 1927 | |
5260325f | 1928 | do_forced_command: |
aa3378df | 1929 | /* |
1930 | * There is a forced command specified for this login. | |
1931 | * Execute it. | |
1932 | */ | |
5260325f | 1933 | debug("Executing forced command: %.900s", forced_command); |
1934 | if (have_pty) | |
1935 | do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); | |
1936 | else | |
1937 | do_exec_no_pty(forced_command, pw, display, proto, data); | |
1938 | return; | |
1939 | } | |
1940 | } | |
8efc0c15 | 1941 | |
5260325f | 1942 | /* |
1943 | * This is called to fork and execute a command when we have no tty. This | |
1944 | * will call do_child from the child, and server_loop from the parent after | |
1945 | * setting up file descriptors and such. | |
1946 | */ | |
1947 | void | |
1948 | do_exec_no_pty(const char *command, struct passwd * pw, | |
1949 | const char *display, const char *auth_proto, | |
1950 | const char *auth_data) | |
1951 | { | |
1952 | int pid; | |
8efc0c15 | 1953 | |
1954 | #ifdef USE_PIPES | |
5260325f | 1955 | int pin[2], pout[2], perr[2]; |
1956 | /* Allocate pipes for communicating with the program. */ | |
1957 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | |
1958 | packet_disconnect("Could not create pipes: %.100s", | |
1959 | strerror(errno)); | |
8efc0c15 | 1960 | #else /* USE_PIPES */ |
5260325f | 1961 | int inout[2], err[2]; |
1962 | /* Uses socket pairs to communicate with the program. */ | |
1963 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | |
1964 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | |
1965 | packet_disconnect("Could not create socket pairs: %.100s", | |
1966 | strerror(errno)); | |
8efc0c15 | 1967 | #endif /* USE_PIPES */ |
8efc0c15 | 1968 | |
5260325f | 1969 | setproctitle("%s@notty", pw->pw_name); |
8efc0c15 | 1970 | |
07b0cb78 | 1971 | #ifdef USE_PAM |
1972 | do_pam_setcred(); | |
1973 | #endif /* USE_PAM */ | |
1974 | ||
5260325f | 1975 | /* Fork the child. */ |
1976 | if ((pid = fork()) == 0) { | |
1977 | /* Child. Reinitialize the log since the pid has changed. */ | |
1978 | log_init(av0, options.log_level, options.log_facility, log_stderr); | |
1979 | ||
aa3378df | 1980 | /* |
1981 | * Create a new session and process group since the 4.4BSD | |
1982 | * setlogin() affects the entire process group. | |
1983 | */ | |
5260325f | 1984 | if (setsid() < 0) |
1985 | error("setsid failed: %.100s", strerror(errno)); | |
8efc0c15 | 1986 | |
1987 | #ifdef USE_PIPES | |
aa3378df | 1988 | /* |
1989 | * Redirect stdin. We close the parent side of the socket | |
1990 | * pair, and make the child side the standard input. | |
1991 | */ | |
5260325f | 1992 | close(pin[1]); |
1993 | if (dup2(pin[0], 0) < 0) | |
1994 | perror("dup2 stdin"); | |
1995 | close(pin[0]); | |
1996 | ||
1997 | /* Redirect stdout. */ | |
1998 | close(pout[0]); | |
1999 | if (dup2(pout[1], 1) < 0) | |
2000 | perror("dup2 stdout"); | |
2001 | close(pout[1]); | |
2002 | ||
2003 | /* Redirect stderr. */ | |
2004 | close(perr[0]); | |
2005 | if (dup2(perr[1], 2) < 0) | |
2006 | perror("dup2 stderr"); | |
2007 | close(perr[1]); | |
8efc0c15 | 2008 | #else /* USE_PIPES */ |
aa3378df | 2009 | /* |
2010 | * Redirect stdin, stdout, and stderr. Stdin and stdout will | |
2011 | * use the same socket, as some programs (particularly rdist) | |
2012 | * seem to depend on it. | |
2013 | */ | |
5260325f | 2014 | close(inout[1]); |
2015 | close(err[1]); | |
2016 | if (dup2(inout[0], 0) < 0) /* stdin */ | |
2017 | perror("dup2 stdin"); | |
2018 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | |
2019 | perror("dup2 stdout"); | |
2020 | if (dup2(err[0], 2) < 0) /* stderr */ | |
2021 | perror("dup2 stderr"); | |
8efc0c15 | 2022 | #endif /* USE_PIPES */ |
2023 | ||
5260325f | 2024 | /* Do processing for the child (exec command etc). */ |
2025 | do_child(command, pw, NULL, display, auth_proto, auth_data, NULL); | |
2026 | /* NOTREACHED */ | |
2027 | } | |
2028 | if (pid < 0) | |
2029 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
8efc0c15 | 2030 | #ifdef USE_PIPES |
5260325f | 2031 | /* We are the parent. Close the child sides of the pipes. */ |
2032 | close(pin[0]); | |
2033 | close(pout[1]); | |
2034 | close(perr[1]); | |
2035 | ||
2036 | /* Enter the interactive session. */ | |
2037 | server_loop(pid, pin[1], pout[0], perr[0]); | |
2038 | /* server_loop has closed pin[1], pout[1], and perr[1]. */ | |
8efc0c15 | 2039 | #else /* USE_PIPES */ |
5260325f | 2040 | /* We are the parent. Close the child sides of the socket pairs. */ |
2041 | close(inout[0]); | |
2042 | close(err[0]); | |
2043 | ||
aa3378df | 2044 | /* |
2045 | * Enter the interactive session. Note: server_loop must be able to | |
2046 | * handle the case that fdin and fdout are the same. | |
2047 | */ | |
5260325f | 2048 | server_loop(pid, inout[1], inout[1], err[1]); |
2049 | /* server_loop has closed inout[1] and err[1]. */ | |
8efc0c15 | 2050 | #endif /* USE_PIPES */ |
2051 | } | |
2052 | ||
5260325f | 2053 | /* |
2054 | * This is called to fork and execute a command when we have a tty. This | |
2055 | * will call do_child from the child, and server_loop from the parent after | |
2056 | * setting up file descriptors, controlling tty, updating wtmp, utmp, | |
2057 | * lastlog, and other such operations. | |
2058 | */ | |
2059 | void | |
2060 | do_exec_pty(const char *command, int ptyfd, int ttyfd, | |
2061 | const char *ttyname, struct passwd * pw, const char *term, | |
2062 | const char *display, const char *auth_proto, | |
2063 | const char *auth_data) | |
8efc0c15 | 2064 | { |
5260325f | 2065 | int pid, fdout; |
c8d54615 | 2066 | int ptymaster; |
5260325f | 2067 | const char *hostname; |
2068 | time_t last_login_time; | |
2069 | char buf[100], *time_string; | |
2070 | FILE *f; | |
2071 | char line[256]; | |
2072 | struct stat st; | |
2073 | int quiet_login; | |
48e671d5 | 2074 | struct sockaddr_storage from; |
2075 | socklen_t fromlen; | |
5260325f | 2076 | struct pty_cleanup_context cleanup_context; |
2077 | ||
2078 | /* Get remote host name. */ | |
2079 | hostname = get_canonical_hostname(); | |
2080 | ||
aa3378df | 2081 | /* |
2082 | * Get the time when the user last logged in. Buf will be set to | |
2083 | * contain the hostname the last login was from. | |
2084 | */ | |
5260325f | 2085 | if (!options.use_login) { |
2086 | last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, | |
2087 | buf, sizeof(buf)); | |
8efc0c15 | 2088 | } |
5260325f | 2089 | setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1); |
2090 | ||
07b0cb78 | 2091 | #ifdef USE_PAM |
2092 | do_pam_session(pw->pw_name, ttyname); | |
2093 | do_pam_setcred(); | |
2094 | #endif /* USE_PAM */ | |
2095 | ||
5260325f | 2096 | /* Fork the child. */ |
2097 | if ((pid = fork()) == 0) { | |
2098 | pid = getpid(); | |
2099 | ||
2100 | /* Child. Reinitialize the log because the pid has | |
2101 | changed. */ | |
2102 | log_init(av0, options.log_level, options.log_facility, log_stderr); | |
2103 | ||
2104 | /* Close the master side of the pseudo tty. */ | |
2105 | close(ptyfd); | |
2106 | ||
2107 | /* Make the pseudo tty our controlling tty. */ | |
2108 | pty_make_controlling_tty(&ttyfd, ttyname); | |
2109 | ||
2110 | /* Redirect stdin from the pseudo tty. */ | |
2111 | if (dup2(ttyfd, fileno(stdin)) < 0) | |
2112 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
2113 | ||
2114 | /* Redirect stdout to the pseudo tty. */ | |
2115 | if (dup2(ttyfd, fileno(stdout)) < 0) | |
2116 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
2117 | ||
2118 | /* Redirect stderr to the pseudo tty. */ | |
2119 | if (dup2(ttyfd, fileno(stderr)) < 0) | |
2120 | error("dup2 stdin failed: %.100s", strerror(errno)); | |
2121 | ||
2122 | /* Close the extra descriptor for the pseudo tty. */ | |
2123 | close(ttyfd); | |
2124 | ||
aa3378df | 2125 | /* |
2126 | * Get IP address of client. This is needed because we want | |
2127 | * to record where the user logged in from. If the | |
2128 | * connection is not a socket, let the ip address be 0.0.0.0. | |
2129 | */ | |
5260325f | 2130 | memset(&from, 0, sizeof(from)); |
2131 | if (packet_get_connection_in() == packet_get_connection_out()) { | |
2132 | fromlen = sizeof(from); | |
2133 | if (getpeername(packet_get_connection_in(), | |
2134 | (struct sockaddr *) & from, &fromlen) < 0) { | |
2135 | debug("getpeername: %.100s", strerror(errno)); | |
2136 | fatal_cleanup(); | |
2137 | } | |
2138 | } | |
2139 | /* Record that there was a login on that terminal. */ | |
2140 | record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname, | |
48e671d5 | 2141 | (struct sockaddr *)&from); |
8efc0c15 | 2142 | |
5260325f | 2143 | /* Check if .hushlogin exists. */ |
2144 | snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); | |
2145 | quiet_login = stat(line, &st) >= 0; | |
e1a9c08d | 2146 | |
d94aa2ae | 2147 | #ifdef USE_PAM |
a5c9cd31 | 2148 | if (!quiet_login) |
2149 | print_pam_messages(); | |
2150 | #endif /* USE_PAM */ | |
8efc0c15 | 2151 | |
aa3378df | 2152 | /* |
2153 | * If the user has logged in before, display the time of last | |
2154 | * login. However, don't display anything extra if a command | |
2155 | * has been specified (so that ssh can be used to execute | |
2156 | * commands on a remote machine without users knowing they | |
2157 | * are going to another machine). Login(1) will do this for | |
2158 | * us as well, so check if login(1) is used | |
2159 | */ | |
5260325f | 2160 | if (command == NULL && last_login_time != 0 && !quiet_login && |
2161 | !options.use_login) { | |
2162 | /* Convert the date to a string. */ | |
2163 | time_string = ctime(&last_login_time); | |
2164 | /* Remove the trailing newline. */ | |
2165 | if (strchr(time_string, '\n')) | |
2166 | *strchr(time_string, '\n') = 0; | |
2167 | /* Display the last login time. Host if displayed | |
2168 | if known. */ | |
2169 | if (strcmp(buf, "") == 0) | |
2170 | printf("Last login: %s\r\n", time_string); | |
2171 | else | |
2172 | printf("Last login: %s from %s\r\n", time_string, buf); | |
2173 | } | |
aa3378df | 2174 | /* |
2175 | * Print /etc/motd unless a command was specified or printing | |
2176 | * it was disabled in server options or login(1) will be | |
2177 | * used. Note that some machines appear to print it in | |
2178 | * /etc/profile or similar. | |
2179 | */ | |
5260325f | 2180 | if (command == NULL && options.print_motd && !quiet_login && |
2181 | !options.use_login) { | |
2182 | /* Print /etc/motd if it exists. */ | |
2183 | f = fopen("/etc/motd", "r"); | |
2184 | if (f) { | |
2185 | while (fgets(line, sizeof(line), f)) | |
2186 | fputs(line, stdout); | |
2187 | fclose(f); | |
2188 | } | |
2189 | } | |
2190 | /* Do common processing for the child, such as execing the command. */ | |
2191 | do_child(command, pw, term, display, auth_proto, auth_data, ttyname); | |
2192 | /* NOTREACHED */ | |
8efc0c15 | 2193 | } |
5260325f | 2194 | if (pid < 0) |
2195 | packet_disconnect("fork failed: %.100s", strerror(errno)); | |
2196 | /* Parent. Close the slave side of the pseudo tty. */ | |
2197 | close(ttyfd); | |
2198 | ||
817175bc | 2199 | /* |
2200 | * Add a cleanup function to clear the utmp entry and record logout | |
2201 | * time in case we call fatal() (e.g., the connection gets closed). | |
2202 | */ | |
2203 | cleanup_context.pid = pid; | |
2204 | cleanup_context.ttyname = ttyname; | |
2205 | fatal_add_cleanup(pty_cleanup_proc, (void *) &cleanup_context); | |
2206 | fatal_remove_cleanup(pty_release_proc, (void *) ttyname); | |
2207 | ||
aa3378df | 2208 | /* |
2209 | * Create another descriptor of the pty master side for use as the | |
2210 | * standard input. We could use the original descriptor, but this | |
2211 | * simplifies code in server_loop. The descriptor is bidirectional. | |
2212 | */ | |
5260325f | 2213 | fdout = dup(ptyfd); |
2214 | if (fdout < 0) | |
c8d54615 | 2215 | packet_disconnect("dup #1 failed: %.100s", strerror(errno)); |
2216 | ||
2217 | /* we keep a reference to the pty master */ | |
2218 | ptymaster = dup(ptyfd); | |
2219 | if (ptymaster < 0) | |
2220 | packet_disconnect("dup #2 failed: %.100s", strerror(errno)); | |
5260325f | 2221 | |
5260325f | 2222 | /* Enter interactive session. */ |
2223 | server_loop(pid, ptyfd, fdout, -1); | |
c8d54615 | 2224 | /* server_loop _has_ closed ptyfd and fdout. */ |
5260325f | 2225 | |
2226 | /* Cancel the cleanup function. */ | |
2227 | fatal_remove_cleanup(pty_cleanup_proc, (void *) &cleanup_context); | |
2228 | ||
2229 | /* Record that the user has logged out. */ | |
2230 | record_logout(pid, ttyname); | |
2231 | ||
2232 | /* Release the pseudo-tty. */ | |
2233 | pty_release(ttyname); | |
2234 | ||
aa3378df | 2235 | /* |
2236 | * Close the server side of the socket pairs. We must do this after | |
2237 | * the pty cleanup, so that another process doesn't get this pty | |
2238 | * while we're still cleaning up. | |
2239 | */ | |
c8d54615 | 2240 | if (close(ptymaster) < 0) |
2241 | error("close(ptymaster): %s", strerror(errno)); | |
8efc0c15 | 2242 | } |
2243 | ||
5260325f | 2244 | /* |
2245 | * Sets the value of the given variable in the environment. If the variable | |
2246 | * already exists, its value is overriden. | |
2247 | */ | |
2248 | void | |
2249 | child_set_env(char ***envp, unsigned int *envsizep, const char *name, | |
2250 | const char *value) | |
8efc0c15 | 2251 | { |
5260325f | 2252 | unsigned int i, namelen; |
2253 | char **env; | |
2254 | ||
aa3378df | 2255 | /* |
2256 | * Find the slot where the value should be stored. If the variable | |
2257 | * already exists, we reuse the slot; otherwise we append a new slot | |
2258 | * at the end of the array, expanding if necessary. | |
2259 | */ | |
5260325f | 2260 | env = *envp; |
2261 | namelen = strlen(name); | |
2262 | for (i = 0; env[i]; i++) | |
2263 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | |
2264 | break; | |
2265 | if (env[i]) { | |
aa3378df | 2266 | /* Reuse the slot. */ |
5260325f | 2267 | xfree(env[i]); |
2268 | } else { | |
aa3378df | 2269 | /* New variable. Expand if necessary. */ |
5260325f | 2270 | if (i >= (*envsizep) - 1) { |
2271 | (*envsizep) += 50; | |
2272 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | |
2273 | } | |
2274 | /* Need to set the NULL pointer at end of array beyond the new slot. */ | |
2275 | env[i + 1] = NULL; | |
8efc0c15 | 2276 | } |
2277 | ||
5260325f | 2278 | /* Allocate space and format the variable in the appropriate slot. */ |
2279 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | |
2280 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | |
8efc0c15 | 2281 | } |
2282 | ||
5260325f | 2283 | /* |
2284 | * Reads environment variables from the given file and adds/overrides them | |
2285 | * into the environment. If the file does not exist, this does nothing. | |
2286 | * Otherwise, it must consist of empty lines, comments (line starts with '#') | |
2287 | * and assignments of the form name=value. No other forms are allowed. | |
2288 | */ | |
2289 | void | |
2290 | read_environment_file(char ***env, unsigned int *envsize, | |
2291 | const char *filename) | |
8efc0c15 | 2292 | { |
5260325f | 2293 | FILE *f; |
2294 | char buf[4096]; | |
2295 | char *cp, *value; | |
2296 | ||
5260325f | 2297 | f = fopen(filename, "r"); |
2298 | if (!f) | |
2299 | return; | |
2300 | ||
5260325f | 2301 | while (fgets(buf, sizeof(buf), f)) { |
aa3378df | 2302 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) |
2303 | ; | |
5260325f | 2304 | if (!*cp || *cp == '#' || *cp == '\n') |
2305 | continue; | |
5260325f | 2306 | if (strchr(cp, '\n')) |
2307 | *strchr(cp, '\n') = '\0'; | |
5260325f | 2308 | value = strchr(cp, '='); |
2309 | if (value == NULL) { | |
2310 | fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); | |
2311 | continue; | |
2312 | } | |
aa3378df | 2313 | /* Replace the equals sign by nul, and advance value to the value string. */ |
5260325f | 2314 | *value = '\0'; |
2315 | value++; | |
5260325f | 2316 | child_set_env(env, envsize, cp, value); |
2317 | } | |
5260325f | 2318 | fclose(f); |
8efc0c15 | 2319 | } |
2320 | ||
a5c9cd31 | 2321 | #ifdef USE_PAM |
2322 | /* | |
2323 | * Sets any environment variables which have been specified by PAM | |
2324 | */ | |
2325 | void do_pam_environment(char ***env, int *envsize) | |
2326 | { | |
2327 | char *equals, var_name[512], var_val[512]; | |
2328 | char **pam_env; | |
2329 | int i; | |
2330 | ||
2331 | if ((pam_env = fetch_pam_environment()) == NULL) | |
2332 | return; | |
2333 | ||
2334 | for(i = 0; pam_env[i] != NULL; i++) { | |
2335 | if ((equals = strstr(pam_env[i], "=")) == NULL) | |
2336 | continue; | |
2337 | ||
2338 | if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) | |
2339 | { | |
2340 | memset(var_name, '\0', sizeof(var_name)); | |
2341 | memset(var_val, '\0', sizeof(var_val)); | |
2342 | ||
2343 | strncpy(var_name, pam_env[i], equals - pam_env[i]); | |
2344 | strcpy(var_val, equals + 1); | |
2345 | ||
2346 | debug("PAM environment: %s=%s", var_name, var_val); | |
2347 | ||
2348 | child_set_env(env, envsize, var_name, var_val); | |
2349 | } | |
2350 | } | |
2351 | } | |
2352 | #endif /* USE_PAM */ | |
2353 | ||
5260325f | 2354 | /* |
2355 | * Performs common processing for the child, such as setting up the | |
2356 | * environment, closing extra file descriptors, setting the user and group | |
2357 | * ids, and executing the command or shell. | |
2358 | */ | |
2359 | void | |
2360 | do_child(const char *command, struct passwd * pw, const char *term, | |
2361 | const char *display, const char *auth_proto, | |
2362 | const char *auth_data, const char *ttyname) | |
8efc0c15 | 2363 | { |
5260325f | 2364 | const char *shell, *cp = NULL; |
2365 | char buf[256]; | |
2366 | FILE *f; | |
2367 | unsigned int envsize, i; | |
2368 | char **env; | |
2369 | extern char **environ; | |
2370 | struct stat st; | |
2371 | char *argv[10]; | |
8efc0c15 | 2372 | |
d94aa2ae | 2373 | #ifndef USE_PAM /* pam_nologin handles this */ |
5260325f | 2374 | /* Check /etc/nologin. */ |
2375 | f = fopen("/etc/nologin", "r"); | |
2376 | if (f) { | |
2377 | /* /etc/nologin exists. Print its contents and exit. */ | |
2378 | while (fgets(buf, sizeof(buf), f)) | |
2379 | fputs(buf, stderr); | |
2380 | fclose(f); | |
2381 | if (pw->pw_uid != 0) | |
2382 | exit(254); | |
2383 | } | |
d94aa2ae | 2384 | #endif /* USE_PAM */ |
e35c1dc2 | 2385 | |
5260325f | 2386 | /* Set login name in the kernel. */ |
2387 | if (setlogin(pw->pw_name) < 0) | |
2388 | error("setlogin failed: %s", strerror(errno)); | |
8efc0c15 | 2389 | |
5260325f | 2390 | /* Set uid, gid, and groups. */ |
2391 | /* Login(1) does this as well, and it needs uid 0 for the "-h" | |
2392 | switch, so we let login(1) to this for us. */ | |
2393 | if (!options.use_login) { | |
2394 | if (getuid() == 0 || geteuid() == 0) { | |
2395 | if (setgid(pw->pw_gid) < 0) { | |
2396 | perror("setgid"); | |
2397 | exit(1); | |
2398 | } | |
2399 | /* Initialize the group list. */ | |
2400 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { | |
2401 | perror("initgroups"); | |
2402 | exit(1); | |
2403 | } | |
2404 | endgrent(); | |
2405 | ||
2406 | /* Permanently switch to the desired uid. */ | |
2407 | permanently_set_uid(pw->pw_uid); | |
2408 | } | |
2409 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | |
2410 | fatal("Failed to set uids to %d.", (int) pw->pw_uid); | |
2411 | } | |
aa3378df | 2412 | /* |
2413 | * Get the shell from the password data. An empty shell field is | |
2414 | * legal, and means /bin/sh. | |
2415 | */ | |
5260325f | 2416 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; |
8efc0c15 | 2417 | |
2418 | #ifdef AFS | |
5260325f | 2419 | /* Try to get AFS tokens for the local cell. */ |
2420 | if (k_hasafs()) { | |
2421 | char cell[64]; | |
2422 | ||
2423 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | |
2424 | krb_afslog(cell, 0); | |
2425 | ||
2426 | krb_afslog(0, 0); | |
2427 | } | |
8efc0c15 | 2428 | #endif /* AFS */ |
5260325f | 2429 | |
aa3378df | 2430 | /* Initialize the environment. */ |
5260325f | 2431 | envsize = 100; |
2432 | env = xmalloc(envsize * sizeof(char *)); | |
2433 | env[0] = NULL; | |
2434 | ||
2435 | if (!options.use_login) { | |
2436 | /* Set basic environment. */ | |
2437 | child_set_env(&env, &envsize, "USER", pw->pw_name); | |
2438 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | |
2439 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | |
2440 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | |
2441 | ||
2442 | snprintf(buf, sizeof buf, "%.200s/%.50s", | |
2443 | _PATH_MAILDIR, pw->pw_name); | |
2444 | child_set_env(&env, &envsize, "MAIL", buf); | |
2445 | ||
2446 | /* Normal systems set SHELL by default. */ | |
2447 | child_set_env(&env, &envsize, "SHELL", shell); | |
2448 | } | |
5260325f | 2449 | if (getenv("TZ")) |
2450 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | |
2451 | ||
2452 | /* Set custom environment options from RSA authentication. */ | |
2453 | while (custom_environment) { | |
2454 | struct envstring *ce = custom_environment; | |
2455 | char *s = ce->s; | |
2456 | int i; | |
2457 | for (i = 0; s[i] != '=' && s[i]; i++); | |
2458 | if (s[i] == '=') { | |
2459 | s[i] = 0; | |
2460 | child_set_env(&env, &envsize, s, s + i + 1); | |
2461 | } | |
2462 | custom_environment = ce->next; | |
2463 | xfree(ce->s); | |
2464 | xfree(ce); | |
8efc0c15 | 2465 | } |
8efc0c15 | 2466 | |
5260325f | 2467 | snprintf(buf, sizeof buf, "%.50s %d %d", |
48e671d5 | 2468 | get_remote_ipaddr(), get_remote_port(), get_local_port()); |
5260325f | 2469 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
8efc0c15 | 2470 | |
5260325f | 2471 | if (ttyname) |
2472 | child_set_env(&env, &envsize, "SSH_TTY", ttyname); | |
5260325f | 2473 | if (term) |
2474 | child_set_env(&env, &envsize, "TERM", term); | |
5260325f | 2475 | if (display) |
2476 | child_set_env(&env, &envsize, "DISPLAY", display); | |
8efc0c15 | 2477 | |
4c40f834 | 2478 | #ifdef _AIX |
2479 | { | |
2480 | char *authstate,*krb5cc; | |
2481 | ||
2482 | if ((authstate = getenv("AUTHSTATE")) != NULL) | |
2483 | child_set_env(&env,&envsize,"AUTHSTATE",authstate); | |
2484 | ||
2485 | if ((krb5cc = getenv("KRB5CCNAME")) != NULL) | |
2486 | child_set_env(&env,&envsize,"KRB5CCNAME",krb5cc); | |
2487 | } | |
2488 | #endif | |
2489 | ||
8efc0c15 | 2490 | #ifdef KRB4 |
5260325f | 2491 | { |
2492 | extern char *ticket; | |
2493 | ||
2494 | if (ticket) | |
2495 | child_set_env(&env, &envsize, "KRBTKFILE", ticket); | |
2496 | } | |
8efc0c15 | 2497 | #endif /* KRB4 */ |
2498 | ||
d94aa2ae | 2499 | #ifdef USE_PAM |
5260325f | 2500 | /* Pull in any environment variables that may have been set by PAM. */ |
a5c9cd31 | 2501 | do_pam_environment(&env, &envsize); |
d94aa2ae | 2502 | #endif /* USE_PAM */ |
bb0dd7f6 | 2503 | |
5260325f | 2504 | if (xauthfile) |
2505 | child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); | |
2506 | ||
5260325f | 2507 | if (auth_get_socket_name() != NULL) |
2508 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | |
2509 | auth_get_socket_name()); | |
2510 | ||
4c40f834 | 2511 | read_environment_file(&env,&envsize,"/etc/environment"); |
2512 | ||
aa3378df | 2513 | /* read $HOME/.ssh/environment. */ |
5260325f | 2514 | if (!options.use_login) { |
2515 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); | |
2516 | read_environment_file(&env, &envsize, buf); | |
2517 | } | |
5260325f | 2518 | if (debug_flag) { |
aa3378df | 2519 | /* dump the environment */ |
5260325f | 2520 | fprintf(stderr, "Environment:\n"); |
2521 | for (i = 0; env[i]; i++) | |
2522 | fprintf(stderr, " %.200s\n", env[i]); | |
2523 | } | |
aa3378df | 2524 | /* |
2525 | * Close the connection descriptors; note that this is the child, and | |
2526 | * the server will still have the socket open, and it is important | |
2527 | * that we do not shutdown it. Note that the descriptors cannot be | |
2528 | * closed before building the environment, as we call | |
2529 | * get_remote_ipaddr there. | |
2530 | */ | |
5260325f | 2531 | if (packet_get_connection_in() == packet_get_connection_out()) |
2532 | close(packet_get_connection_in()); | |
2533 | else { | |
2534 | close(packet_get_connection_in()); | |
2535 | close(packet_get_connection_out()); | |
2536 | } | |
aa3378df | 2537 | /* |
2538 | * Close all descriptors related to channels. They will still remain | |
2539 | * open in the parent. | |
2540 | */ | |
2541 | /* XXX better use close-on-exec? -markus */ | |
5260325f | 2542 | channel_close_all(); |
2543 | ||
aa3378df | 2544 | /* |
2545 | * Close any extra file descriptors. Note that there may still be | |
2546 | * descriptors left by system functions. They will be closed later. | |
2547 | */ | |
5260325f | 2548 | endpwent(); |
5260325f | 2549 | |
aa3378df | 2550 | /* |
2551 | * Close any extra open file descriptors so that we don\'t have them | |
2552 | * hanging around in clients. Note that we want to do this after | |
2553 | * initgroups, because at least on Solaris 2.3 it leaves file | |
2554 | * descriptors open. | |
2555 | */ | |
5260325f | 2556 | for (i = 3; i < 64; i++) |
2557 | close(i); | |
2558 | ||
2559 | /* Change current directory to the user\'s home directory. */ | |
2560 | if (chdir(pw->pw_dir) < 0) | |
2561 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | |
2562 | pw->pw_dir, strerror(errno)); | |
2563 | ||
aa3378df | 2564 | /* |
2565 | * Must take new environment into use so that .ssh/rc, /etc/sshrc and | |
2566 | * xauth are run in the proper environment. | |
2567 | */ | |
5260325f | 2568 | environ = env; |
2569 | ||
aa3378df | 2570 | /* |
2571 | * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first | |
2572 | * in this order). | |
2573 | */ | |
5260325f | 2574 | if (!options.use_login) { |
2575 | if (stat(SSH_USER_RC, &st) >= 0) { | |
2576 | if (debug_flag) | |
2577 | fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); | |
2578 | ||
2579 | f = popen("/bin/sh " SSH_USER_RC, "w"); | |
2580 | if (f) { | |
2581 | if (auth_proto != NULL && auth_data != NULL) | |
2582 | fprintf(f, "%s %s\n", auth_proto, auth_data); | |
2583 | pclose(f); | |
2584 | } else | |
2585 | fprintf(stderr, "Could not run %s\n", SSH_USER_RC); | |
2586 | } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { | |
2587 | if (debug_flag) | |
2588 | fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); | |
2589 | ||
2590 | f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); | |
2591 | if (f) { | |
2592 | if (auth_proto != NULL && auth_data != NULL) | |
2593 | fprintf(f, "%s %s\n", auth_proto, auth_data); | |
2594 | pclose(f); | |
2595 | } else | |
2596 | fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); | |
2597 | } | |
8efc0c15 | 2598 | #ifdef XAUTH_PATH |
5260325f | 2599 | else { |
aa3378df | 2600 | /* Add authority data to .Xauthority if appropriate. */ |
5260325f | 2601 | if (auth_proto != NULL && auth_data != NULL) { |
2602 | if (debug_flag) | |
2603 | fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", | |
2604 | XAUTH_PATH, display, auth_proto, auth_data); | |
2605 | ||
2606 | f = popen(XAUTH_PATH " -q -", "w"); | |
2607 | if (f) { | |
2608 | fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); | |
c8d54615 | 2609 | pclose(f); |
5260325f | 2610 | } else |
2611 | fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); | |
2612 | } | |
2613 | } | |
8efc0c15 | 2614 | #endif /* XAUTH_PATH */ |
2615 | ||
5260325f | 2616 | /* Get the last component of the shell name. */ |
2617 | cp = strrchr(shell, '/'); | |
2618 | if (cp) | |
2619 | cp++; | |
2620 | else | |
2621 | cp = shell; | |
2622 | } | |
aa3378df | 2623 | /* |
2624 | * If we have no command, execute the shell. In this case, the shell | |
2625 | * name to be passed in argv[0] is preceded by '-' to indicate that | |
2626 | * this is a login shell. | |
2627 | */ | |
5260325f | 2628 | if (!command) { |
2629 | if (!options.use_login) { | |
2630 | char buf[256]; | |
2631 | ||
aa3378df | 2632 | /* |
2633 | * Check for mail if we have a tty and it was enabled | |
2634 | * in server options. | |
2635 | */ | |
5260325f | 2636 | if (ttyname && options.check_mail) { |
2637 | char *mailbox; | |
2638 | struct stat mailstat; | |
2639 | mailbox = getenv("MAIL"); | |
2640 | if (mailbox != NULL) { | |
2641 | if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) | |
2642 | printf("No mail.\n"); | |
2643 | else if (mailstat.st_mtime < mailstat.st_atime) | |
2644 | printf("You have mail.\n"); | |
2645 | else | |
2646 | printf("You have new mail.\n"); | |
2647 | } | |
2648 | } | |
2649 | /* Start the shell. Set initial character to '-'. */ | |
2650 | buf[0] = '-'; | |
2651 | strncpy(buf + 1, cp, sizeof(buf) - 1); | |
2652 | buf[sizeof(buf) - 1] = 0; | |
2653 | ||
2654 | /* Execute the shell. */ | |
2655 | argv[0] = buf; | |
2656 | argv[1] = NULL; | |
2657 | execve(shell, argv, env); | |
2658 | ||
2659 | /* Executing the shell failed. */ | |
2660 | perror(shell); | |
2661 | exit(1); | |
2662 | ||
2663 | } else { | |
2664 | /* Launch login(1). */ | |
2665 | ||
2666 | execl(LOGIN_PROGRAM, "login", "-h", get_remote_ipaddr(), | |
2667 | "-p", "-f", "--", pw->pw_name, NULL); | |
2668 | ||
2669 | /* Login couldn't be executed, die. */ | |
2670 | ||
2671 | perror("login"); | |
2672 | exit(1); | |
2673 | } | |
2674 | } | |
aa3378df | 2675 | /* |
2676 | * Execute the command using the user's shell. This uses the -c | |
2677 | * option to execute the command. | |
2678 | */ | |
5260325f | 2679 | argv[0] = (char *) cp; |
2680 | argv[1] = "-c"; | |
2681 | argv[2] = (char *) command; | |
2682 | argv[3] = NULL; | |
2683 | execve(shell, argv, env); | |
2684 | perror(shell); | |
2685 | exit(1); | |
8efc0c15 | 2686 | } |