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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 | #if defined(HAVE_SECURITY_PAM_APPL_H) | |
38 | #include <security/pam_appl.h> | |
39 | #elif defined (HAVE_PAM_PAM_APPL_H) | |
40 | #include <pam/pam_appl.h> | |
41 | #endif | |
42 | ||
43 | #include "auth.h" | |
44 | #include "auth-pam.h" | |
45 | #include "buffer.h" | |
46 | #include "bufaux.h" | |
47 | #include "canohost.h" | |
48 | #include "log.h" | |
49 | #include "monitor_wrap.h" | |
50 | #include "msg.h" | |
51 | #include "packet.h" | |
52 | #include "readpass.h" | |
53 | #include "servconf.h" | |
54 | #include "ssh2.h" | |
55 | #include "xmalloc.h" | |
56 | #include "auth-options.h" | |
57 | ||
58 | extern ServerOptions options; | |
59 | extern Buffer loginmsg; | |
60 | extern int compat20; | |
61 | ||
62 | #ifdef USE_POSIX_THREADS | |
63 | #include <pthread.h> | |
64 | /* | |
65 | * Avoid namespace clash when *not* using pthreads for systems *with* | |
66 | * pthreads, which unconditionally define pthread_t via sys/types.h | |
67 | * (e.g. Linux) | |
68 | */ | |
69 | typedef pthread_t sp_pthread_t; | |
70 | #else | |
71 | typedef pid_t sp_pthread_t; | |
72 | #endif | |
73 | ||
74 | struct pam_ctxt { | |
75 | sp_pthread_t pam_thread; | |
76 | int pam_psock; | |
77 | int pam_csock; | |
78 | int pam_done; | |
79 | }; | |
80 | ||
81 | static void sshpam_free_ctx(void *); | |
82 | static struct pam_ctxt *cleanup_ctxt; | |
83 | ||
84 | #ifndef USE_POSIX_THREADS | |
85 | /* | |
86 | * Simulate threads with processes. | |
87 | */ | |
88 | ||
89 | static void | |
90 | pthread_exit(void *value __unused) | |
91 | { | |
92 | _exit(0); | |
93 | } | |
94 | ||
95 | static int | |
96 | pthread_create(sp_pthread_t *thread, const void *attr __unused, | |
97 | void *(*thread_start)(void *), void *arg) | |
98 | { | |
99 | pid_t pid; | |
100 | ||
101 | switch ((pid = fork())) { | |
102 | case -1: | |
103 | error("fork(): %s", strerror(errno)); | |
104 | return (-1); | |
105 | case 0: | |
106 | thread_start(arg); | |
107 | _exit(1); | |
108 | default: | |
109 | *thread = pid; | |
110 | return (0); | |
111 | } | |
112 | } | |
113 | ||
114 | static int | |
115 | pthread_cancel(sp_pthread_t thread) | |
116 | { | |
117 | return (kill(thread, SIGTERM)); | |
118 | } | |
119 | ||
120 | static int | |
121 | pthread_join(sp_pthread_t thread, void **value __unused) | |
122 | { | |
123 | int status; | |
124 | ||
125 | waitpid(thread, &status, 0); | |
126 | return (status); | |
127 | } | |
128 | #endif | |
129 | ||
130 | ||
131 | static pam_handle_t *sshpam_handle = NULL; | |
132 | static int sshpam_err = 0; | |
133 | static int sshpam_authenticated = 0; | |
134 | static int sshpam_new_authtok_reqd = 0; | |
135 | static int sshpam_session_open = 0; | |
136 | static int sshpam_cred_established = 0; | |
137 | static int sshpam_account_status = -1; | |
138 | static char **sshpam_env = NULL; | |
139 | ||
140 | /* Some PAM implementations don't implement this */ | |
141 | #ifndef HAVE_PAM_GETENVLIST | |
142 | static char ** | |
143 | pam_getenvlist(pam_handle_t *pamh) | |
144 | { | |
145 | /* | |
146 | * XXX - If necessary, we can still support envrionment passing | |
147 | * for platforms without pam_getenvlist by searching for known | |
148 | * env vars (e.g. KRB5CCNAME) from the PAM environment. | |
149 | */ | |
150 | return NULL; | |
151 | } | |
152 | #endif | |
153 | ||
154 | void | |
155 | pam_password_change_required(int reqd) | |
156 | { | |
157 | sshpam_new_authtok_reqd = reqd; | |
158 | if (reqd) { | |
159 | no_port_forwarding_flag |= 2; | |
160 | no_agent_forwarding_flag |= 2; | |
161 | no_x11_forwarding_flag |= 2; | |
162 | } else { | |
163 | no_port_forwarding_flag &= ~2; | |
164 | no_agent_forwarding_flag &= ~2; | |
165 | no_x11_forwarding_flag &= ~2; | |
166 | ||
167 | } | |
168 | } | |
169 | /* Import regular and PAM environment from subprocess */ | |
170 | static void | |
171 | import_environments(Buffer *b) | |
172 | { | |
173 | char *env; | |
174 | u_int i, num_env; | |
175 | int err; | |
176 | ||
177 | /* Import variables set by do_pam_account */ | |
178 | sshpam_account_status = buffer_get_int(b); | |
179 | pam_password_change_required(buffer_get_int(b)); | |
180 | ||
181 | /* Import environment from subprocess */ | |
182 | num_env = buffer_get_int(b); | |
183 | sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env)); | |
184 | debug3("PAM: num env strings %d", num_env); | |
185 | for(i = 0; i < num_env; i++) | |
186 | sshpam_env[i] = buffer_get_string(b, NULL); | |
187 | ||
188 | sshpam_env[num_env] = NULL; | |
189 | ||
190 | /* Import PAM environment from subprocess */ | |
191 | num_env = buffer_get_int(b); | |
192 | debug("PAM: num PAM env strings %d", num_env); | |
193 | for(i = 0; i < num_env; i++) { | |
194 | env = buffer_get_string(b, NULL); | |
195 | ||
196 | #ifdef HAVE_PAM_PUTENV | |
197 | /* Errors are not fatal here */ | |
198 | if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { | |
199 | error("PAM: pam_putenv: %s", | |
200 | pam_strerror(sshpam_handle, sshpam_err)); | |
201 | } | |
202 | #endif | |
203 | } | |
204 | } | |
205 | ||
206 | /* | |
207 | * Conversation function for authentication thread. | |
208 | */ | |
209 | static int | |
210 | sshpam_thread_conv(int n, const struct pam_message **msg, | |
211 | struct pam_response **resp, void *data) | |
212 | { | |
213 | Buffer buffer; | |
214 | struct pam_ctxt *ctxt; | |
215 | struct pam_response *reply; | |
216 | int i; | |
217 | ||
218 | *resp = NULL; | |
219 | ||
220 | ctxt = data; | |
221 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
222 | return (PAM_CONV_ERR); | |
223 | ||
224 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
225 | return (PAM_CONV_ERR); | |
226 | memset(reply, 0, n * sizeof(*reply)); | |
227 | ||
228 | buffer_init(&buffer); | |
229 | for (i = 0; i < n; ++i) { | |
230 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
231 | case PAM_PROMPT_ECHO_OFF: | |
232 | buffer_put_cstring(&buffer, | |
233 | PAM_MSG_MEMBER(msg, i, msg)); | |
234 | if (ssh_msg_send(ctxt->pam_csock, | |
235 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
236 | goto fail; | |
237 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
238 | goto fail; | |
239 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) | |
240 | goto fail; | |
241 | reply[i].resp = buffer_get_string(&buffer, NULL); | |
242 | break; | |
243 | case PAM_PROMPT_ECHO_ON: | |
244 | buffer_put_cstring(&buffer, | |
245 | PAM_MSG_MEMBER(msg, i, msg)); | |
246 | if (ssh_msg_send(ctxt->pam_csock, | |
247 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
248 | goto fail; | |
249 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
250 | goto fail; | |
251 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) | |
252 | goto fail; | |
253 | reply[i].resp = buffer_get_string(&buffer, NULL); | |
254 | break; | |
255 | case PAM_ERROR_MSG: | |
256 | buffer_put_cstring(&buffer, | |
257 | PAM_MSG_MEMBER(msg, i, msg)); | |
258 | if (ssh_msg_send(ctxt->pam_csock, | |
259 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
260 | goto fail; | |
261 | break; | |
262 | case PAM_TEXT_INFO: | |
263 | buffer_put_cstring(&buffer, | |
264 | PAM_MSG_MEMBER(msg, i, msg)); | |
265 | if (ssh_msg_send(ctxt->pam_csock, | |
266 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
267 | goto fail; | |
268 | break; | |
269 | default: | |
270 | goto fail; | |
271 | } | |
272 | buffer_clear(&buffer); | |
273 | } | |
274 | buffer_free(&buffer); | |
275 | *resp = reply; | |
276 | return (PAM_SUCCESS); | |
277 | ||
278 | fail: | |
279 | for(i = 0; i < n; i++) { | |
280 | if (reply[i].resp != NULL) | |
281 | xfree(reply[i].resp); | |
282 | } | |
283 | xfree(reply); | |
284 | buffer_free(&buffer); | |
285 | return (PAM_CONV_ERR); | |
286 | } | |
287 | ||
288 | /* | |
289 | * Authentication thread. | |
290 | */ | |
291 | static void * | |
292 | sshpam_thread(void *ctxtp) | |
293 | { | |
294 | struct pam_ctxt *ctxt = ctxtp; | |
295 | Buffer buffer; | |
296 | struct pam_conv sshpam_conv; | |
297 | #ifndef USE_POSIX_THREADS | |
298 | extern char **environ; | |
299 | char **env_from_pam; | |
300 | u_int i; | |
301 | const char *pam_user; | |
302 | ||
303 | pam_get_item(sshpam_handle, PAM_USER, (const void **)&pam_user); | |
304 | setproctitle("%s [pam]", pam_user); | |
305 | environ[0] = NULL; | |
306 | #endif | |
307 | ||
308 | sshpam_conv.conv = sshpam_thread_conv; | |
309 | sshpam_conv.appdata_ptr = ctxt; | |
310 | ||
311 | buffer_init(&buffer); | |
312 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
313 | (const void *)&sshpam_conv); | |
314 | if (sshpam_err != PAM_SUCCESS) | |
315 | goto auth_fail; | |
316 | sshpam_err = pam_authenticate(sshpam_handle, 0); | |
317 | if (sshpam_err != PAM_SUCCESS) | |
318 | goto auth_fail; | |
319 | ||
320 | if (compat20) { | |
321 | if (!do_pam_account()) | |
322 | goto auth_fail; | |
323 | if (sshpam_new_authtok_reqd) { | |
324 | sshpam_err = pam_chauthtok(sshpam_handle, | |
325 | PAM_CHANGE_EXPIRED_AUTHTOK); | |
326 | if (sshpam_err != PAM_SUCCESS) | |
327 | goto auth_fail; | |
328 | pam_password_change_required(0); | |
329 | } | |
330 | } | |
331 | ||
332 | buffer_put_cstring(&buffer, "OK"); | |
333 | ||
334 | #ifndef USE_POSIX_THREADS | |
335 | /* Export variables set by do_pam_account */ | |
336 | buffer_put_int(&buffer, sshpam_account_status); | |
337 | buffer_put_int(&buffer, sshpam_new_authtok_reqd); | |
338 | ||
339 | /* Export any environment strings set in child */ | |
340 | for(i = 0; environ[i] != NULL; i++) | |
341 | ; /* Count */ | |
342 | buffer_put_int(&buffer, i); | |
343 | for(i = 0; environ[i] != NULL; i++) | |
344 | buffer_put_cstring(&buffer, environ[i]); | |
345 | ||
346 | /* Export any environment strings set by PAM in child */ | |
347 | env_from_pam = pam_getenvlist(sshpam_handle); | |
348 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
349 | ; /* Count */ | |
350 | buffer_put_int(&buffer, i); | |
351 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
352 | buffer_put_cstring(&buffer, env_from_pam[i]); | |
353 | #endif /* USE_POSIX_THREADS */ | |
354 | ||
355 | /* XXX - can't do much about an error here */ | |
356 | ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); | |
357 | buffer_free(&buffer); | |
358 | pthread_exit(NULL); | |
359 | ||
360 | auth_fail: | |
361 | buffer_put_cstring(&buffer, | |
362 | pam_strerror(sshpam_handle, sshpam_err)); | |
363 | /* XXX - can't do much about an error here */ | |
364 | ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); | |
365 | buffer_free(&buffer); | |
366 | pthread_exit(NULL); | |
367 | ||
368 | return (NULL); /* Avoid warning for non-pthread case */ | |
369 | } | |
370 | ||
371 | void | |
372 | sshpam_thread_cleanup(void) | |
373 | { | |
374 | struct pam_ctxt *ctxt = cleanup_ctxt; | |
375 | ||
376 | if (ctxt != NULL && ctxt->pam_thread != 0) { | |
377 | pthread_cancel(ctxt->pam_thread); | |
378 | pthread_join(ctxt->pam_thread, NULL); | |
379 | close(ctxt->pam_psock); | |
380 | close(ctxt->pam_csock); | |
381 | memset(ctxt, 0, sizeof(*ctxt)); | |
382 | cleanup_ctxt = NULL; | |
383 | } | |
384 | } | |
385 | ||
386 | static int | |
387 | sshpam_null_conv(int n, const struct pam_message **msg, | |
388 | struct pam_response **resp, void *data) | |
389 | { | |
390 | return (PAM_CONV_ERR); | |
391 | } | |
392 | ||
393 | static struct pam_conv null_conv = { sshpam_null_conv, NULL }; | |
394 | ||
395 | void | |
396 | sshpam_cleanup(void) | |
397 | { | |
398 | debug("PAM: cleanup"); | |
399 | if (sshpam_handle == NULL) | |
400 | return; | |
401 | pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); | |
402 | if (sshpam_cred_established) { | |
403 | pam_setcred(sshpam_handle, PAM_DELETE_CRED); | |
404 | sshpam_cred_established = 0; | |
405 | } | |
406 | if (sshpam_session_open) { | |
407 | pam_close_session(sshpam_handle, PAM_SILENT); | |
408 | sshpam_session_open = 0; | |
409 | } | |
410 | sshpam_authenticated = sshpam_new_authtok_reqd = 0; | |
411 | pam_end(sshpam_handle, sshpam_err); | |
412 | sshpam_handle = NULL; | |
413 | } | |
414 | ||
415 | static int | |
416 | sshpam_init(const char *user) | |
417 | { | |
418 | extern u_int utmp_len; | |
419 | extern char *__progname; | |
420 | const char *pam_rhost, *pam_user; | |
421 | ||
422 | if (sshpam_handle != NULL) { | |
423 | /* We already have a PAM context; check if the user matches */ | |
424 | sshpam_err = pam_get_item(sshpam_handle, | |
425 | PAM_USER, (const void **)&pam_user); | |
426 | if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) | |
427 | return (0); | |
428 | pam_end(sshpam_handle, sshpam_err); | |
429 | sshpam_handle = NULL; | |
430 | } | |
431 | debug("PAM: initializing for \"%s\"", user); | |
432 | sshpam_err = | |
433 | pam_start(SSHD_PAM_SERVICE, user, &null_conv, &sshpam_handle); | |
434 | if (sshpam_err != PAM_SUCCESS) { | |
435 | pam_end(sshpam_handle, sshpam_err); | |
436 | sshpam_handle = NULL; | |
437 | return (-1); | |
438 | } | |
439 | pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); | |
440 | debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); | |
441 | sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); | |
442 | if (sshpam_err != PAM_SUCCESS) { | |
443 | pam_end(sshpam_handle, sshpam_err); | |
444 | sshpam_handle = NULL; | |
445 | return (-1); | |
446 | } | |
447 | #ifdef PAM_TTY_KLUDGE | |
448 | /* | |
449 | * Some silly PAM modules (e.g. pam_time) require a TTY to operate. | |
450 | * sshd doesn't set the tty until too late in the auth process and | |
451 | * may not even set one (for tty-less connections) | |
452 | */ | |
453 | debug("PAM: setting PAM_TTY to \"ssh\""); | |
454 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); | |
455 | if (sshpam_err != PAM_SUCCESS) { | |
456 | pam_end(sshpam_handle, sshpam_err); | |
457 | sshpam_handle = NULL; | |
458 | return (-1); | |
459 | } | |
460 | #endif | |
461 | return (0); | |
462 | } | |
463 | ||
464 | static void * | |
465 | sshpam_init_ctx(Authctxt *authctxt) | |
466 | { | |
467 | struct pam_ctxt *ctxt; | |
468 | int socks[2]; | |
469 | ||
470 | /* Refuse to start if we don't have PAM enabled */ | |
471 | if (!options.use_pam) | |
472 | return NULL; | |
473 | ||
474 | /* Initialize PAM */ | |
475 | if (sshpam_init(authctxt->user) == -1) { | |
476 | error("PAM: initialization failed"); | |
477 | return (NULL); | |
478 | } | |
479 | ||
480 | ctxt = xmalloc(sizeof *ctxt); | |
481 | memset(ctxt, 0, sizeof(*ctxt)); | |
482 | ||
483 | /* Start the authentication thread */ | |
484 | if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { | |
485 | error("PAM: failed create sockets: %s", strerror(errno)); | |
486 | xfree(ctxt); | |
487 | return (NULL); | |
488 | } | |
489 | ctxt->pam_psock = socks[0]; | |
490 | ctxt->pam_csock = socks[1]; | |
491 | if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { | |
492 | error("PAM: failed to start authentication thread: %s", | |
493 | strerror(errno)); | |
494 | close(socks[0]); | |
495 | close(socks[1]); | |
496 | xfree(ctxt); | |
497 | return (NULL); | |
498 | } | |
499 | cleanup_ctxt = ctxt; | |
500 | return (ctxt); | |
501 | } | |
502 | ||
503 | static int | |
504 | sshpam_query(void *ctx, char **name, char **info, | |
505 | u_int *num, char ***prompts, u_int **echo_on) | |
506 | { | |
507 | Buffer buffer; | |
508 | struct pam_ctxt *ctxt = ctx; | |
509 | size_t plen; | |
510 | u_char type; | |
511 | char *msg; | |
512 | size_t len; | |
513 | ||
514 | buffer_init(&buffer); | |
515 | *name = xstrdup(""); | |
516 | *info = xstrdup(""); | |
517 | *prompts = xmalloc(sizeof(char *)); | |
518 | **prompts = NULL; | |
519 | plen = 0; | |
520 | *echo_on = xmalloc(sizeof(u_int)); | |
521 | while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { | |
522 | type = buffer_get_char(&buffer); | |
523 | msg = buffer_get_string(&buffer, NULL); | |
524 | switch (type) { | |
525 | case PAM_PROMPT_ECHO_ON: | |
526 | case PAM_PROMPT_ECHO_OFF: | |
527 | *num = 1; | |
528 | len = plen + strlen(msg) + 1; | |
529 | **prompts = xrealloc(**prompts, len); | |
530 | plen += snprintf(**prompts + plen, len, "%s", msg); | |
531 | **echo_on = (type == PAM_PROMPT_ECHO_ON); | |
532 | xfree(msg); | |
533 | return (0); | |
534 | case PAM_ERROR_MSG: | |
535 | case PAM_TEXT_INFO: | |
536 | /* accumulate messages */ | |
537 | len = plen + strlen(msg) + 2; | |
538 | **prompts = xrealloc(**prompts, len); | |
539 | plen += snprintf(**prompts + plen, len, "%s\n", msg); | |
540 | xfree(msg); | |
541 | break; | |
542 | case PAM_SUCCESS: | |
543 | case PAM_AUTH_ERR: | |
544 | if (**prompts != NULL) { | |
545 | /* drain any accumulated messages */ | |
546 | debug("PAM: %s", **prompts); | |
547 | buffer_append(&loginmsg, **prompts, | |
548 | strlen(**prompts)); | |
549 | xfree(**prompts); | |
550 | **prompts = NULL; | |
551 | } | |
552 | if (type == PAM_SUCCESS) { | |
553 | import_environments(&buffer); | |
554 | *num = 0; | |
555 | **echo_on = 0; | |
556 | ctxt->pam_done = 1; | |
557 | xfree(msg); | |
558 | return (0); | |
559 | } | |
560 | error("PAM: %s", msg); | |
561 | /* FALLTHROUGH */ | |
562 | default: | |
563 | *num = 0; | |
564 | **echo_on = 0; | |
565 | xfree(msg); | |
566 | ctxt->pam_done = -1; | |
567 | return (-1); | |
568 | } | |
569 | } | |
570 | return (-1); | |
571 | } | |
572 | ||
573 | /* XXX - see also comment in auth-chall.c:verify_response */ | |
574 | static int | |
575 | sshpam_respond(void *ctx, u_int num, char **resp) | |
576 | { | |
577 | Buffer buffer; | |
578 | struct pam_ctxt *ctxt = ctx; | |
579 | ||
580 | debug2("PAM: %s", __func__); | |
581 | switch (ctxt->pam_done) { | |
582 | case 1: | |
583 | sshpam_authenticated = 1; | |
584 | return (0); | |
585 | case 0: | |
586 | break; | |
587 | default: | |
588 | return (-1); | |
589 | } | |
590 | if (num != 1) { | |
591 | error("PAM: expected one response, got %u", num); | |
592 | return (-1); | |
593 | } | |
594 | buffer_init(&buffer); | |
595 | buffer_put_cstring(&buffer, *resp); | |
596 | if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { | |
597 | buffer_free(&buffer); | |
598 | return (-1); | |
599 | } | |
600 | buffer_free(&buffer); | |
601 | return (1); | |
602 | } | |
603 | ||
604 | static void | |
605 | sshpam_free_ctx(void *ctxtp) | |
606 | { | |
607 | struct pam_ctxt *ctxt = ctxtp; | |
608 | ||
609 | sshpam_thread_cleanup(); | |
610 | xfree(ctxt); | |
611 | /* | |
612 | * We don't call sshpam_cleanup() here because we may need the PAM | |
613 | * handle at a later stage, e.g. when setting up a session. It's | |
614 | * still on the cleanup list, so pam_end() *will* be called before | |
615 | * the server process terminates. | |
616 | */ | |
617 | } | |
618 | ||
619 | KbdintDevice sshpam_device = { | |
620 | "pam", | |
621 | sshpam_init_ctx, | |
622 | sshpam_query, | |
623 | sshpam_respond, | |
624 | sshpam_free_ctx | |
625 | }; | |
626 | ||
627 | KbdintDevice mm_sshpam_device = { | |
628 | "pam", | |
629 | mm_sshpam_init_ctx, | |
630 | mm_sshpam_query, | |
631 | mm_sshpam_respond, | |
632 | mm_sshpam_free_ctx | |
633 | }; | |
634 | ||
635 | /* | |
636 | * This replaces auth-pam.c | |
637 | */ | |
638 | void | |
639 | start_pam(const char *user) | |
640 | { | |
641 | if (!options.use_pam) | |
642 | fatal("PAM: initialisation requested when UsePAM=no"); | |
643 | ||
644 | if (sshpam_init(user) == -1) | |
645 | fatal("PAM: initialisation failed"); | |
646 | } | |
647 | ||
648 | void | |
649 | finish_pam(void) | |
650 | { | |
651 | sshpam_cleanup(); | |
652 | } | |
653 | ||
654 | u_int | |
655 | do_pam_account(void) | |
656 | { | |
657 | if (sshpam_account_status != -1) | |
658 | return (sshpam_account_status); | |
659 | ||
660 | sshpam_err = pam_acct_mgmt(sshpam_handle, 0); | |
661 | debug3("%s: pam_acct_mgmt = %d", __func__, sshpam_err); | |
662 | ||
663 | if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) { | |
664 | sshpam_account_status = 0; | |
665 | return (sshpam_account_status); | |
666 | } | |
667 | ||
668 | if (sshpam_err == PAM_NEW_AUTHTOK_REQD) | |
669 | pam_password_change_required(1); | |
670 | ||
671 | sshpam_account_status = 1; | |
672 | return (sshpam_account_status); | |
673 | } | |
674 | ||
675 | void | |
676 | do_pam_set_tty(const char *tty) | |
677 | { | |
678 | if (tty != NULL) { | |
679 | debug("PAM: setting PAM_TTY to \"%s\"", tty); | |
680 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); | |
681 | if (sshpam_err != PAM_SUCCESS) | |
682 | fatal("PAM: failed to set PAM_TTY: %s", | |
683 | pam_strerror(sshpam_handle, sshpam_err)); | |
684 | } | |
685 | } | |
686 | ||
687 | void | |
688 | do_pam_setcred(int init) | |
689 | { | |
690 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
691 | (const void *)&null_conv); | |
692 | if (sshpam_err != PAM_SUCCESS) | |
693 | fatal("PAM: failed to set PAM_CONV: %s", | |
694 | pam_strerror(sshpam_handle, sshpam_err)); | |
695 | if (init) { | |
696 | debug("PAM: establishing credentials"); | |
697 | sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); | |
698 | } else { | |
699 | debug("PAM: reinitializing credentials"); | |
700 | sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); | |
701 | } | |
702 | if (sshpam_err == PAM_SUCCESS) { | |
703 | sshpam_cred_established = 1; | |
704 | return; | |
705 | } | |
706 | if (sshpam_authenticated) | |
707 | fatal("PAM: pam_setcred(): %s", | |
708 | pam_strerror(sshpam_handle, sshpam_err)); | |
709 | else | |
710 | debug("PAM: pam_setcred(): %s", | |
711 | pam_strerror(sshpam_handle, sshpam_err)); | |
712 | } | |
713 | ||
714 | int | |
715 | is_pam_password_change_required(void) | |
716 | { | |
717 | return (sshpam_new_authtok_reqd); | |
718 | } | |
719 | ||
720 | static int | |
721 | pam_tty_conv(int n, const struct pam_message **msg, | |
722 | struct pam_response **resp, void *data) | |
723 | { | |
724 | char input[PAM_MAX_MSG_SIZE]; | |
725 | struct pam_response *reply; | |
726 | int i; | |
727 | ||
728 | *resp = NULL; | |
729 | ||
730 | if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) | |
731 | return (PAM_CONV_ERR); | |
732 | ||
733 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
734 | return (PAM_CONV_ERR); | |
735 | memset(reply, 0, n * sizeof(*reply)); | |
736 | ||
737 | for (i = 0; i < n; ++i) { | |
738 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
739 | case PAM_PROMPT_ECHO_OFF: | |
740 | reply[i].resp = | |
741 | read_passphrase(PAM_MSG_MEMBER(msg, i, msg), | |
742 | RP_ALLOW_STDIN); | |
743 | reply[i].resp_retcode = PAM_SUCCESS; | |
744 | break; | |
745 | case PAM_PROMPT_ECHO_ON: | |
746 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); | |
747 | fgets(input, sizeof input, stdin); | |
748 | reply[i].resp = xstrdup(input); | |
749 | reply[i].resp_retcode = PAM_SUCCESS; | |
750 | break; | |
751 | case PAM_ERROR_MSG: | |
752 | case PAM_TEXT_INFO: | |
753 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); | |
754 | reply[i].resp_retcode = PAM_SUCCESS; | |
755 | break; | |
756 | default: | |
757 | goto fail; | |
758 | } | |
759 | } | |
760 | *resp = reply; | |
761 | return (PAM_SUCCESS); | |
762 | ||
763 | fail: | |
764 | for(i = 0; i < n; i++) { | |
765 | if (reply[i].resp != NULL) | |
766 | xfree(reply[i].resp); | |
767 | } | |
768 | xfree(reply); | |
769 | return (PAM_CONV_ERR); | |
770 | } | |
771 | ||
772 | static struct pam_conv tty_conv = { pam_tty_conv, NULL }; | |
773 | ||
774 | /* | |
775 | * XXX this should be done in the authentication phase, but ssh1 doesn't | |
776 | * support that | |
777 | */ | |
778 | void | |
779 | do_pam_chauthtok(void) | |
780 | { | |
781 | if (use_privsep) | |
782 | fatal("Password expired (unable to change with privsep)"); | |
783 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
784 | (const void *)&tty_conv); | |
785 | if (sshpam_err != PAM_SUCCESS) | |
786 | fatal("PAM: failed to set PAM_CONV: %s", | |
787 | pam_strerror(sshpam_handle, sshpam_err)); | |
788 | debug("PAM: changing password"); | |
789 | sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); | |
790 | if (sshpam_err != PAM_SUCCESS) | |
791 | fatal("PAM: pam_chauthtok(): %s", | |
792 | pam_strerror(sshpam_handle, sshpam_err)); | |
793 | } | |
794 | ||
795 | void | |
796 | do_pam_session(void) | |
797 | { | |
798 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
799 | (const void *)&tty_conv); | |
800 | if (sshpam_err != PAM_SUCCESS) | |
801 | fatal("PAM: failed to set PAM_CONV: %s", | |
802 | pam_strerror(sshpam_handle, sshpam_err)); | |
803 | sshpam_err = pam_open_session(sshpam_handle, 0); | |
804 | if (sshpam_err != PAM_SUCCESS) | |
805 | fatal("PAM: pam_open_session(): %s", | |
806 | pam_strerror(sshpam_handle, sshpam_err)); | |
807 | sshpam_session_open = 1; | |
808 | } | |
809 | ||
810 | /* | |
811 | * Set a PAM environment string. We need to do this so that the session | |
812 | * modules can handle things like Kerberos/GSI credentials that appear | |
813 | * during the ssh authentication process. | |
814 | */ | |
815 | int | |
816 | do_pam_putenv(char *name, char *value) | |
817 | { | |
818 | int ret = 1; | |
819 | #ifdef HAVE_PAM_PUTENV | |
820 | char *compound; | |
821 | size_t len; | |
822 | ||
823 | len = strlen(name) + strlen(value) + 2; | |
824 | compound = xmalloc(len); | |
825 | ||
826 | snprintf(compound, len, "%s=%s", name, value); | |
827 | ret = pam_putenv(sshpam_handle, compound); | |
828 | xfree(compound); | |
829 | #endif | |
830 | ||
831 | return (ret); | |
832 | } | |
833 | ||
834 | void | |
835 | print_pam_messages(void) | |
836 | { | |
837 | /* XXX */ | |
838 | } | |
839 | ||
840 | char ** | |
841 | fetch_pam_child_environment(void) | |
842 | { | |
843 | return sshpam_env; | |
844 | } | |
845 | ||
846 | char ** | |
847 | fetch_pam_environment(void) | |
848 | { | |
849 | return (pam_getenvlist(sshpam_handle)); | |
850 | } | |
851 | ||
852 | void | |
853 | free_pam_environment(char **env) | |
854 | { | |
855 | char **envp; | |
856 | ||
857 | if (env == NULL) | |
858 | return; | |
859 | ||
860 | for (envp = env; *envp; envp++) | |
861 | xfree(*envp); | |
862 | xfree(env); | |
863 | } | |
864 | ||
865 | #endif /* USE_PAM */ |