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1 | /*- | |
2 | * Copyright (c) 2002 Networks Associates Technology, Inc. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This software was developed for the FreeBSD Project by ThinkSec AS and | |
6 | * NAI Labs, the Security Research Division of Network Associates, Inc. | |
7 | * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the | |
8 | * DARPA CHATS research program. | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or without | |
11 | * modification, are permitted provided that the following conditions | |
12 | * are met: | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * | |
19 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
29 | * SUCH DAMAGE. | |
30 | */ | |
31 | ||
32 | /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */ | |
33 | #include "includes.h" | |
34 | RCSID("$Id$"); | |
35 | ||
36 | #ifdef USE_PAM | |
37 | #include <security/pam_appl.h> | |
38 | ||
39 | #include "auth.h" | |
40 | #include "auth-pam.h" | |
41 | #include "buffer.h" | |
42 | #include "bufaux.h" | |
43 | #include "canohost.h" | |
44 | #include "log.h" | |
45 | #include "monitor_wrap.h" | |
46 | #include "msg.h" | |
47 | #include "packet.h" | |
48 | #include "readpass.h" | |
49 | #include "servconf.h" | |
50 | #include "ssh2.h" | |
51 | #include "xmalloc.h" | |
52 | #include "auth-options.h" | |
53 | ||
54 | extern ServerOptions options; | |
55 | extern Buffer loginmsg; | |
56 | ||
57 | #define __unused | |
58 | ||
59 | #ifdef USE_POSIX_THREADS | |
60 | #include <pthread.h> | |
61 | /* | |
62 | * Avoid namespace clash when *not* using pthreads for systems *with* | |
63 | * pthreads, which unconditionally define pthread_t via sys/types.h | |
64 | * (e.g. Linux) | |
65 | */ | |
66 | typedef pthread_t sp_pthread_t; | |
67 | #else | |
68 | /* | |
69 | * Simulate threads with processes. | |
70 | */ | |
71 | typedef pid_t sp_pthread_t; | |
72 | ||
73 | static void | |
74 | pthread_exit(void *value __unused) | |
75 | { | |
76 | _exit(0); | |
77 | } | |
78 | ||
79 | static int | |
80 | pthread_create(sp_pthread_t *thread, const void *attr __unused, | |
81 | void *(*thread_start)(void *), void *arg) | |
82 | { | |
83 | pid_t pid; | |
84 | ||
85 | switch ((pid = fork())) { | |
86 | case -1: | |
87 | error("fork(): %s", strerror(errno)); | |
88 | return (-1); | |
89 | case 0: | |
90 | thread_start(arg); | |
91 | _exit(1); | |
92 | default: | |
93 | *thread = pid; | |
94 | return (0); | |
95 | } | |
96 | } | |
97 | ||
98 | static int | |
99 | pthread_cancel(sp_pthread_t thread) | |
100 | { | |
101 | return (kill(thread, SIGTERM)); | |
102 | } | |
103 | ||
104 | static int | |
105 | pthread_join(sp_pthread_t thread, void **value __unused) | |
106 | { | |
107 | int status; | |
108 | ||
109 | waitpid(thread, &status, 0); | |
110 | return (status); | |
111 | } | |
112 | #endif | |
113 | ||
114 | ||
115 | static pam_handle_t *sshpam_handle = NULL; | |
116 | static int sshpam_err = 0; | |
117 | static int sshpam_authenticated = 0; | |
118 | static int sshpam_new_authtok_reqd = 0; | |
119 | static int sshpam_session_open = 0; | |
120 | static int sshpam_cred_established = 0; | |
121 | static char **sshpam_env = NULL; | |
122 | ||
123 | struct pam_ctxt { | |
124 | sp_pthread_t pam_thread; | |
125 | int pam_psock; | |
126 | int pam_csock; | |
127 | int pam_done; | |
128 | }; | |
129 | ||
130 | static void sshpam_free_ctx(void *); | |
131 | static struct pam_ctxt *cleanup_ctxt; | |
132 | ||
133 | /* Some PAM implementations don't implement this */ | |
134 | #ifndef HAVE_PAM_GETENVLIST | |
135 | static char ** | |
136 | pam_getenvlist(pam_handle_t *pamh) | |
137 | { | |
138 | /* | |
139 | * XXX - If necessary, we can still support envrionment passing | |
140 | * for platforms without pam_getenvlist by searching for known | |
141 | * env vars (e.g. KRB5CCNAME) from the PAM environment. | |
142 | */ | |
143 | return NULL; | |
144 | } | |
145 | #endif | |
146 | ||
147 | /* Import regular and PAM environment from subprocess */ | |
148 | static void | |
149 | import_environments(Buffer *b) | |
150 | { | |
151 | char *env; | |
152 | u_int i, num_env; | |
153 | int err; | |
154 | ||
155 | /* Import environment from subprocess */ | |
156 | num_env = buffer_get_int(b); | |
157 | sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env)); | |
158 | debug3("PAM: num env strings %d", num_env); | |
159 | for(i = 0; i < num_env; i++) | |
160 | sshpam_env[i] = buffer_get_string(b, NULL); | |
161 | ||
162 | sshpam_env[num_env] = NULL; | |
163 | ||
164 | /* Import PAM environment from subprocess */ | |
165 | num_env = buffer_get_int(b); | |
166 | debug("PAM: num PAM env strings %d", num_env); | |
167 | for(i = 0; i < num_env; i++) { | |
168 | env = buffer_get_string(b, NULL); | |
169 | ||
170 | /* Errors are not fatal here */ | |
171 | if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { | |
172 | error("PAM: pam_putenv: %s", | |
173 | pam_strerror(sshpam_handle, sshpam_err)); | |
174 | } | |
175 | } | |
176 | } | |
177 | ||
178 | /* | |
179 | * Conversation function for authentication thread. | |
180 | */ | |
181 | static int | |
182 | sshpam_thread_conv(int n, const struct pam_message **msg, | |
183 | struct pam_response **resp, void *data) | |
184 | { | |
185 | Buffer buffer; | |
186 | struct pam_ctxt *ctxt; | |
187 | struct pam_response *reply; | |
188 | int i; | |
189 | ||
190 | *resp = NULL; | |
191 | ||
192 | ctxt = data; | |
193 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
194 | return (PAM_CONV_ERR); | |
195 | ||
196 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
197 | return (PAM_CONV_ERR); | |
198 | memset(reply, 0, n * sizeof(*reply)); | |
199 | ||
200 | buffer_init(&buffer); | |
201 | for (i = 0; i < n; ++i) { | |
202 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
203 | case PAM_PROMPT_ECHO_OFF: | |
204 | buffer_put_cstring(&buffer, | |
205 | PAM_MSG_MEMBER(msg, i, msg)); | |
206 | if (ssh_msg_send(ctxt->pam_csock, | |
207 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
208 | goto fail; | |
209 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
210 | goto fail; | |
211 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) | |
212 | goto fail; | |
213 | reply[i].resp = buffer_get_string(&buffer, NULL); | |
214 | break; | |
215 | case PAM_PROMPT_ECHO_ON: | |
216 | buffer_put_cstring(&buffer, | |
217 | PAM_MSG_MEMBER(msg, i, msg)); | |
218 | if (ssh_msg_send(ctxt->pam_csock, | |
219 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
220 | goto fail; | |
221 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
222 | goto fail; | |
223 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) | |
224 | goto fail; | |
225 | reply[i].resp = buffer_get_string(&buffer, NULL); | |
226 | break; | |
227 | case PAM_ERROR_MSG: | |
228 | buffer_put_cstring(&buffer, | |
229 | PAM_MSG_MEMBER(msg, i, msg)); | |
230 | if (ssh_msg_send(ctxt->pam_csock, | |
231 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
232 | goto fail; | |
233 | break; | |
234 | case PAM_TEXT_INFO: | |
235 | buffer_put_cstring(&buffer, | |
236 | PAM_MSG_MEMBER(msg, i, msg)); | |
237 | if (ssh_msg_send(ctxt->pam_csock, | |
238 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
239 | goto fail; | |
240 | break; | |
241 | default: | |
242 | goto fail; | |
243 | } | |
244 | buffer_clear(&buffer); | |
245 | } | |
246 | buffer_free(&buffer); | |
247 | *resp = reply; | |
248 | return (PAM_SUCCESS); | |
249 | ||
250 | fail: | |
251 | for(i = 0; i < n; i++) { | |
252 | if (reply[i].resp != NULL) | |
253 | xfree(reply[i].resp); | |
254 | } | |
255 | xfree(reply); | |
256 | buffer_free(&buffer); | |
257 | return (PAM_CONV_ERR); | |
258 | } | |
259 | ||
260 | /* | |
261 | * Authentication thread. | |
262 | */ | |
263 | static void * | |
264 | sshpam_thread(void *ctxtp) | |
265 | { | |
266 | struct pam_ctxt *ctxt = ctxtp; | |
267 | Buffer buffer; | |
268 | struct pam_conv sshpam_conv; | |
269 | #ifndef USE_POSIX_THREADS | |
270 | extern char **environ; | |
271 | char **env_from_pam; | |
272 | u_int i; | |
273 | const char *pam_user; | |
274 | ||
275 | pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user); | |
276 | setproctitle("%s [pam]", pam_user); | |
277 | environ[0] = NULL; | |
278 | #endif | |
279 | ||
280 | sshpam_conv.conv = sshpam_thread_conv; | |
281 | sshpam_conv.appdata_ptr = ctxt; | |
282 | ||
283 | buffer_init(&buffer); | |
284 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
285 | (const void *)&sshpam_conv); | |
286 | if (sshpam_err != PAM_SUCCESS) | |
287 | goto auth_fail; | |
288 | sshpam_err = pam_authenticate(sshpam_handle, 0); | |
289 | if (sshpam_err != PAM_SUCCESS) | |
290 | goto auth_fail; | |
291 | buffer_put_cstring(&buffer, "OK"); | |
292 | ||
293 | #ifndef USE_POSIX_THREADS | |
294 | /* Export any environment strings set in child */ | |
295 | for(i = 0; environ[i] != NULL; i++) | |
296 | ; /* Count */ | |
297 | buffer_put_int(&buffer, i); | |
298 | for(i = 0; environ[i] != NULL; i++) | |
299 | buffer_put_cstring(&buffer, environ[i]); | |
300 | ||
301 | /* Export any environment strings set by PAM in child */ | |
302 | env_from_pam = pam_getenvlist(sshpam_handle); | |
303 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
304 | ; /* Count */ | |
305 | buffer_put_int(&buffer, i); | |
306 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
307 | buffer_put_cstring(&buffer, env_from_pam[i]); | |
308 | #endif /* USE_POSIX_THREADS */ | |
309 | ||
310 | /* XXX - can't do much about an error here */ | |
311 | ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); | |
312 | buffer_free(&buffer); | |
313 | pthread_exit(NULL); | |
314 | ||
315 | auth_fail: | |
316 | buffer_put_cstring(&buffer, | |
317 | pam_strerror(sshpam_handle, sshpam_err)); | |
318 | /* XXX - can't do much about an error here */ | |
319 | ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); | |
320 | buffer_free(&buffer); | |
321 | pthread_exit(NULL); | |
322 | ||
323 | return (NULL); /* Avoid warning for non-pthread case */ | |
324 | } | |
325 | ||
326 | void | |
327 | sshpam_thread_cleanup(void) | |
328 | { | |
329 | struct pam_ctxt *ctxt = cleanup_ctxt; | |
330 | ||
331 | if (ctxt != NULL && ctxt->pam_thread != 0) { | |
332 | pthread_cancel(ctxt->pam_thread); | |
333 | pthread_join(ctxt->pam_thread, NULL); | |
334 | close(ctxt->pam_psock); | |
335 | close(ctxt->pam_csock); | |
336 | memset(ctxt, 0, sizeof(*ctxt)); | |
337 | cleanup_ctxt = NULL; | |
338 | } | |
339 | } | |
340 | ||
341 | static int | |
342 | sshpam_null_conv(int n, const struct pam_message **msg, | |
343 | struct pam_response **resp, void *data) | |
344 | { | |
345 | return (PAM_CONV_ERR); | |
346 | } | |
347 | ||
348 | static struct pam_conv null_conv = { sshpam_null_conv, NULL }; | |
349 | ||
350 | void | |
351 | sshpam_cleanup(void) | |
352 | { | |
353 | debug("PAM: cleanup"); | |
354 | if (sshpam_handle == NULL) | |
355 | return; | |
356 | pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); | |
357 | if (sshpam_cred_established) { | |
358 | pam_setcred(sshpam_handle, PAM_DELETE_CRED); | |
359 | sshpam_cred_established = 0; | |
360 | } | |
361 | if (sshpam_session_open) { | |
362 | pam_close_session(sshpam_handle, PAM_SILENT); | |
363 | sshpam_session_open = 0; | |
364 | } | |
365 | sshpam_authenticated = sshpam_new_authtok_reqd = 0; | |
366 | pam_end(sshpam_handle, sshpam_err); | |
367 | sshpam_handle = NULL; | |
368 | } | |
369 | ||
370 | static int | |
371 | sshpam_init(const char *user) | |
372 | { | |
373 | extern u_int utmp_len; | |
374 | extern char *__progname; | |
375 | const char *pam_rhost, *pam_user; | |
376 | ||
377 | if (sshpam_handle != NULL) { | |
378 | /* We already have a PAM context; check if the user matches */ | |
379 | sshpam_err = pam_get_item(sshpam_handle, | |
380 | PAM_USER, (const void **)&pam_user); | |
381 | if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) | |
382 | return (0); | |
383 | pam_end(sshpam_handle, sshpam_err); | |
384 | sshpam_handle = NULL; | |
385 | } | |
386 | debug("PAM: initializing for \"%s\"", user); | |
387 | sshpam_err = | |
388 | pam_start(SSHD_PAM_SERVICE, user, &null_conv, &sshpam_handle); | |
389 | if (sshpam_err != PAM_SUCCESS) { | |
390 | pam_end(sshpam_handle, sshpam_err); | |
391 | sshpam_handle = NULL; | |
392 | return (-1); | |
393 | } | |
394 | pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); | |
395 | debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); | |
396 | sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); | |
397 | if (sshpam_err != PAM_SUCCESS) { | |
398 | pam_end(sshpam_handle, sshpam_err); | |
399 | sshpam_handle = NULL; | |
400 | return (-1); | |
401 | } | |
402 | #ifdef PAM_TTY_KLUDGE | |
403 | /* | |
404 | * Some silly PAM modules (e.g. pam_time) require a TTY to operate. | |
405 | * sshd doesn't set the tty until too late in the auth process and | |
406 | * may not even set one (for tty-less connections) | |
407 | */ | |
408 | debug("PAM: setting PAM_TTY to \"ssh\""); | |
409 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); | |
410 | if (sshpam_err != PAM_SUCCESS) { | |
411 | pam_end(sshpam_handle, sshpam_err); | |
412 | sshpam_handle = NULL; | |
413 | return (-1); | |
414 | } | |
415 | #endif | |
416 | return (0); | |
417 | } | |
418 | ||
419 | static void * | |
420 | sshpam_init_ctx(Authctxt *authctxt) | |
421 | { | |
422 | struct pam_ctxt *ctxt; | |
423 | int socks[2]; | |
424 | ||
425 | /* Refuse to start if we don't have PAM enabled */ | |
426 | if (!options.use_pam) | |
427 | return NULL; | |
428 | ||
429 | /* Initialize PAM */ | |
430 | if (sshpam_init(authctxt->user) == -1) { | |
431 | error("PAM: initialization failed"); | |
432 | return (NULL); | |
433 | } | |
434 | ||
435 | ctxt = xmalloc(sizeof *ctxt); | |
436 | memset(ctxt, 0, sizeof(*ctxt)); | |
437 | ||
438 | /* Start the authentication thread */ | |
439 | if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { | |
440 | error("PAM: failed create sockets: %s", strerror(errno)); | |
441 | xfree(ctxt); | |
442 | return (NULL); | |
443 | } | |
444 | ctxt->pam_psock = socks[0]; | |
445 | ctxt->pam_csock = socks[1]; | |
446 | if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { | |
447 | error("PAM: failed to start authentication thread: %s", | |
448 | strerror(errno)); | |
449 | close(socks[0]); | |
450 | close(socks[1]); | |
451 | xfree(ctxt); | |
452 | return (NULL); | |
453 | } | |
454 | cleanup_ctxt = ctxt; | |
455 | return (ctxt); | |
456 | } | |
457 | ||
458 | static int | |
459 | sshpam_query(void *ctx, char **name, char **info, | |
460 | u_int *num, char ***prompts, u_int **echo_on) | |
461 | { | |
462 | Buffer buffer; | |
463 | struct pam_ctxt *ctxt = ctx; | |
464 | size_t plen; | |
465 | u_char type; | |
466 | char *msg; | |
467 | size_t len; | |
468 | ||
469 | buffer_init(&buffer); | |
470 | *name = xstrdup(""); | |
471 | *info = xstrdup(""); | |
472 | *prompts = xmalloc(sizeof(char *)); | |
473 | **prompts = NULL; | |
474 | plen = 0; | |
475 | *echo_on = xmalloc(sizeof(u_int)); | |
476 | while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { | |
477 | type = buffer_get_char(&buffer); | |
478 | msg = buffer_get_string(&buffer, NULL); | |
479 | switch (type) { | |
480 | case PAM_PROMPT_ECHO_ON: | |
481 | case PAM_PROMPT_ECHO_OFF: | |
482 | *num = 1; | |
483 | len = plen + strlen(msg) + 1; | |
484 | **prompts = xrealloc(**prompts, len); | |
485 | plen += snprintf(**prompts + plen, len, "%s", msg); | |
486 | **echo_on = (type == PAM_PROMPT_ECHO_ON); | |
487 | xfree(msg); | |
488 | return (0); | |
489 | case PAM_ERROR_MSG: | |
490 | case PAM_TEXT_INFO: | |
491 | /* accumulate messages */ | |
492 | len = plen + strlen(msg) + 2; | |
493 | **prompts = xrealloc(**prompts, len); | |
494 | plen += snprintf(**prompts + plen, len, "%s\n", msg); | |
495 | xfree(msg); | |
496 | break; | |
497 | case PAM_SUCCESS: | |
498 | case PAM_AUTH_ERR: | |
499 | if (**prompts != NULL) { | |
500 | /* drain any accumulated messages */ | |
501 | debug("PAM: %s", **prompts); | |
502 | buffer_append(&loginmsg, **prompts, | |
503 | strlen(**prompts)); | |
504 | xfree(**prompts); | |
505 | **prompts = NULL; | |
506 | } | |
507 | if (type == PAM_SUCCESS) { | |
508 | import_environments(&buffer); | |
509 | *num = 0; | |
510 | **echo_on = 0; | |
511 | ctxt->pam_done = 1; | |
512 | xfree(msg); | |
513 | return (0); | |
514 | } | |
515 | error("PAM: %s", msg); | |
516 | /* FALLTHROUGH */ | |
517 | default: | |
518 | *num = 0; | |
519 | **echo_on = 0; | |
520 | xfree(msg); | |
521 | ctxt->pam_done = -1; | |
522 | return (-1); | |
523 | } | |
524 | } | |
525 | return (-1); | |
526 | } | |
527 | ||
528 | /* XXX - see also comment in auth-chall.c:verify_response */ | |
529 | static int | |
530 | sshpam_respond(void *ctx, u_int num, char **resp) | |
531 | { | |
532 | Buffer buffer; | |
533 | struct pam_ctxt *ctxt = ctx; | |
534 | ||
535 | debug2("PAM: %s", __func__); | |
536 | switch (ctxt->pam_done) { | |
537 | case 1: | |
538 | sshpam_authenticated = 1; | |
539 | return (0); | |
540 | case 0: | |
541 | break; | |
542 | default: | |
543 | return (-1); | |
544 | } | |
545 | if (num != 1) { | |
546 | error("PAM: expected one response, got %u", num); | |
547 | return (-1); | |
548 | } | |
549 | buffer_init(&buffer); | |
550 | buffer_put_cstring(&buffer, *resp); | |
551 | if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { | |
552 | buffer_free(&buffer); | |
553 | return (-1); | |
554 | } | |
555 | buffer_free(&buffer); | |
556 | return (1); | |
557 | } | |
558 | ||
559 | static void | |
560 | sshpam_free_ctx(void *ctxtp) | |
561 | { | |
562 | struct pam_ctxt *ctxt = ctxtp; | |
563 | ||
564 | sshpam_thread_cleanup(); | |
565 | xfree(ctxt); | |
566 | /* | |
567 | * We don't call sshpam_cleanup() here because we may need the PAM | |
568 | * handle at a later stage, e.g. when setting up a session. It's | |
569 | * still on the cleanup list, so pam_end() *will* be called before | |
570 | * the server process terminates. | |
571 | */ | |
572 | } | |
573 | ||
574 | KbdintDevice sshpam_device = { | |
575 | "pam", | |
576 | sshpam_init_ctx, | |
577 | sshpam_query, | |
578 | sshpam_respond, | |
579 | sshpam_free_ctx | |
580 | }; | |
581 | ||
582 | KbdintDevice mm_sshpam_device = { | |
583 | "pam", | |
584 | mm_sshpam_init_ctx, | |
585 | mm_sshpam_query, | |
586 | mm_sshpam_respond, | |
587 | mm_sshpam_free_ctx | |
588 | }; | |
589 | ||
590 | /* | |
591 | * This replaces auth-pam.c | |
592 | */ | |
593 | void | |
594 | start_pam(const char *user) | |
595 | { | |
596 | if (!options.use_pam) | |
597 | fatal("PAM: initialisation requested when UsePAM=no"); | |
598 | ||
599 | if (sshpam_init(user) == -1) | |
600 | fatal("PAM: initialisation failed"); | |
601 | } | |
602 | ||
603 | void | |
604 | finish_pam(void) | |
605 | { | |
606 | sshpam_cleanup(); | |
607 | } | |
608 | ||
609 | u_int | |
610 | do_pam_account(void) | |
611 | { | |
612 | sshpam_err = pam_acct_mgmt(sshpam_handle, 0); | |
613 | debug3("%s: pam_acct_mgmt = %d", __func__, sshpam_err); | |
614 | ||
615 | if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) | |
616 | return (0); | |
617 | ||
618 | if (sshpam_err == PAM_NEW_AUTHTOK_REQD) { | |
619 | sshpam_new_authtok_reqd = 1; | |
620 | ||
621 | /* Prevent forwardings until password changed */ | |
622 | no_port_forwarding_flag |= 2; | |
623 | no_agent_forwarding_flag |= 2; | |
624 | no_x11_forwarding_flag |= 2; | |
625 | } | |
626 | ||
627 | return (1); | |
628 | } | |
629 | ||
630 | void | |
631 | do_pam_set_tty(const char *tty) | |
632 | { | |
633 | if (tty != NULL) { | |
634 | debug("PAM: setting PAM_TTY to \"%s\"", tty); | |
635 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); | |
636 | if (sshpam_err != PAM_SUCCESS) | |
637 | fatal("PAM: failed to set PAM_TTY: %s", | |
638 | pam_strerror(sshpam_handle, sshpam_err)); | |
639 | } | |
640 | } | |
641 | ||
642 | void | |
643 | do_pam_setcred(int init) | |
644 | { | |
645 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
646 | (const void *)&null_conv); | |
647 | if (sshpam_err != PAM_SUCCESS) | |
648 | fatal("PAM: failed to set PAM_CONV: %s", | |
649 | pam_strerror(sshpam_handle, sshpam_err)); | |
650 | if (init) { | |
651 | debug("PAM: establishing credentials"); | |
652 | sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); | |
653 | } else { | |
654 | debug("PAM: reinitializing credentials"); | |
655 | sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); | |
656 | } | |
657 | if (sshpam_err == PAM_SUCCESS) { | |
658 | sshpam_cred_established = 1; | |
659 | return; | |
660 | } | |
661 | if (sshpam_authenticated) | |
662 | fatal("PAM: pam_setcred(): %s", | |
663 | pam_strerror(sshpam_handle, sshpam_err)); | |
664 | else | |
665 | debug("PAM: pam_setcred(): %s", | |
666 | pam_strerror(sshpam_handle, sshpam_err)); | |
667 | } | |
668 | ||
669 | int | |
670 | is_pam_password_change_required(void) | |
671 | { | |
672 | return (sshpam_new_authtok_reqd); | |
673 | } | |
674 | ||
675 | static int | |
676 | pam_tty_conv(int n, const struct pam_message **msg, | |
677 | struct pam_response **resp, void *data) | |
678 | { | |
679 | char input[PAM_MAX_MSG_SIZE]; | |
680 | struct pam_response *reply; | |
681 | int i; | |
682 | ||
683 | *resp = NULL; | |
684 | ||
685 | if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) | |
686 | return (PAM_CONV_ERR); | |
687 | ||
688 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
689 | return (PAM_CONV_ERR); | |
690 | memset(reply, 0, n * sizeof(*reply)); | |
691 | ||
692 | for (i = 0; i < n; ++i) { | |
693 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
694 | case PAM_PROMPT_ECHO_OFF: | |
695 | reply[i].resp = | |
696 | read_passphrase(PAM_MSG_MEMBER(msg, i, msg), | |
697 | RP_ALLOW_STDIN); | |
698 | reply[i].resp_retcode = PAM_SUCCESS; | |
699 | break; | |
700 | case PAM_PROMPT_ECHO_ON: | |
701 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); | |
702 | fgets(input, sizeof input, stdin); | |
703 | reply[i].resp = xstrdup(input); | |
704 | reply[i].resp_retcode = PAM_SUCCESS; | |
705 | break; | |
706 | case PAM_ERROR_MSG: | |
707 | case PAM_TEXT_INFO: | |
708 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); | |
709 | reply[i].resp_retcode = PAM_SUCCESS; | |
710 | break; | |
711 | default: | |
712 | goto fail; | |
713 | } | |
714 | } | |
715 | *resp = reply; | |
716 | return (PAM_SUCCESS); | |
717 | ||
718 | fail: | |
719 | for(i = 0; i < n; i++) { | |
720 | if (reply[i].resp != NULL) | |
721 | xfree(reply[i].resp); | |
722 | } | |
723 | xfree(reply); | |
724 | return (PAM_CONV_ERR); | |
725 | } | |
726 | ||
727 | static struct pam_conv tty_conv = { pam_tty_conv, NULL }; | |
728 | ||
729 | /* | |
730 | * XXX this should be done in the authentication phase, but ssh1 doesn't | |
731 | * support that | |
732 | */ | |
733 | void | |
734 | do_pam_chauthtok(void) | |
735 | { | |
736 | if (use_privsep) | |
737 | fatal("Password expired (unable to change with privsep)"); | |
738 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
739 | (const void *)&tty_conv); | |
740 | if (sshpam_err != PAM_SUCCESS) | |
741 | fatal("PAM: failed to set PAM_CONV: %s", | |
742 | pam_strerror(sshpam_handle, sshpam_err)); | |
743 | debug("PAM: changing password"); | |
744 | sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); | |
745 | if (sshpam_err != PAM_SUCCESS) | |
746 | fatal("PAM: pam_chauthtok(): %s", | |
747 | pam_strerror(sshpam_handle, sshpam_err)); | |
748 | } | |
749 | ||
750 | void | |
751 | do_pam_session(void) | |
752 | { | |
753 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
754 | (const void *)&tty_conv); | |
755 | if (sshpam_err != PAM_SUCCESS) | |
756 | fatal("PAM: failed to set PAM_CONV: %s", | |
757 | pam_strerror(sshpam_handle, sshpam_err)); | |
758 | sshpam_err = pam_open_session(sshpam_handle, 0); | |
759 | if (sshpam_err != PAM_SUCCESS) | |
760 | fatal("PAM: pam_open_session(): %s", | |
761 | pam_strerror(sshpam_handle, sshpam_err)); | |
762 | sshpam_session_open = 1; | |
763 | } | |
764 | ||
765 | /* | |
766 | * Set a PAM environment string. We need to do this so that the session | |
767 | * modules can handle things like Kerberos/GSI credentials that appear | |
768 | * during the ssh authentication process. | |
769 | */ | |
770 | int | |
771 | do_pam_putenv(char *name, char *value) | |
772 | { | |
773 | int ret = 1; | |
774 | #ifdef HAVE_PAM_PUTENV | |
775 | char *compound; | |
776 | size_t len; | |
777 | ||
778 | len = strlen(name) + strlen(value) + 2; | |
779 | compound = xmalloc(len); | |
780 | ||
781 | snprintf(compound, len, "%s=%s", name, value); | |
782 | ret = pam_putenv(sshpam_handle, compound); | |
783 | xfree(compound); | |
784 | #endif | |
785 | ||
786 | return (ret); | |
787 | } | |
788 | ||
789 | void | |
790 | print_pam_messages(void) | |
791 | { | |
792 | /* XXX */ | |
793 | } | |
794 | ||
795 | char ** | |
796 | fetch_pam_child_environment(void) | |
797 | { | |
798 | return sshpam_env; | |
799 | } | |
800 | ||
801 | char ** | |
802 | fetch_pam_environment(void) | |
803 | { | |
804 | return (pam_getenvlist(sshpam_handle)); | |
805 | } | |
806 | ||
807 | void | |
808 | free_pam_environment(char **env) | |
809 | { | |
810 | char **envp; | |
811 | ||
812 | if (env == NULL) | |
813 | return; | |
814 | ||
815 | for (envp = env; *envp; envp++) | |
816 | xfree(*envp); | |
817 | xfree(env); | |
818 | } | |
819 | ||
820 | #endif /* USE_PAM */ |