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7cac2b65 | 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. | |
3c0ef626 | 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 | * | |
7cac2b65 | 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. | |
3c0ef626 | 30 | */ |
7e82606e | 31 | /* |
32 | * Copyright (c) 2003,2004 Damien Miller <djm@mindrot.org> | |
33 | * Copyright (c) 2003,2004 Darren Tucker <dtucker@zip.com.au> | |
34 | * | |
35 | * Permission to use, copy, modify, and distribute this software for any | |
36 | * purpose with or without fee is hereby granted, provided that the above | |
37 | * copyright notice and this permission notice appear in all copies. | |
38 | * | |
39 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
40 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
41 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
42 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
43 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
44 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
45 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
46 | */ | |
3c0ef626 | 47 | |
7cac2b65 | 48 | /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */ |
3c0ef626 | 49 | #include "includes.h" |
7cac2b65 | 50 | RCSID("$Id$"); |
3c0ef626 | 51 | |
52 | #ifdef USE_PAM | |
540d72c3 | 53 | #if defined(HAVE_SECURITY_PAM_APPL_H) |
7cac2b65 | 54 | #include <security/pam_appl.h> |
540d72c3 | 55 | #elif defined (HAVE_PAM_PAM_APPL_H) |
56 | #include <pam/pam_appl.h> | |
57 | #endif | |
7cac2b65 | 58 | |
350391c5 | 59 | #include "auth.h" |
3c0ef626 | 60 | #include "auth-pam.h" |
7cac2b65 | 61 | #include "buffer.h" |
62 | #include "bufaux.h" | |
3c0ef626 | 63 | #include "canohost.h" |
7cac2b65 | 64 | #include "log.h" |
65 | #include "monitor_wrap.h" | |
66 | #include "msg.h" | |
67 | #include "packet.h" | |
7e82606e | 68 | #include "misc.h" |
7cac2b65 | 69 | #include "servconf.h" |
70 | #include "ssh2.h" | |
71 | #include "xmalloc.h" | |
72 | #include "auth-options.h" | |
3c0ef626 | 73 | |
7cac2b65 | 74 | extern ServerOptions options; |
540d72c3 | 75 | extern Buffer loginmsg; |
76 | extern int compat20; | |
12a403af | 77 | extern u_int utmp_len; |
d03f4262 | 78 | |
8b32eddc | 79 | /* so we don't silently change behaviour */ |
7cac2b65 | 80 | #ifdef USE_POSIX_THREADS |
8b32eddc | 81 | # error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK" |
82 | #endif | |
83 | ||
84 | /* | |
85 | * Formerly known as USE_POSIX_THREADS, using this is completely unsupported | |
86 | * and generally a bad idea. Use at own risk and do not expect support if | |
87 | * this breaks. | |
88 | */ | |
89 | #ifdef UNSUPPORTED_POSIX_THREADS_HACK | |
7cac2b65 | 90 | #include <pthread.h> |
91 | /* | |
540d72c3 | 92 | * Avoid namespace clash when *not* using pthreads for systems *with* |
93 | * pthreads, which unconditionally define pthread_t via sys/types.h | |
7cac2b65 | 94 | * (e.g. Linux) |
95 | */ | |
540d72c3 | 96 | typedef pthread_t sp_pthread_t; |
7cac2b65 | 97 | #else |
540d72c3 | 98 | typedef pid_t sp_pthread_t; |
99 | #endif | |
100 | ||
101 | struct pam_ctxt { | |
102 | sp_pthread_t pam_thread; | |
103 | int pam_psock; | |
104 | int pam_csock; | |
105 | int pam_done; | |
106 | }; | |
107 | ||
108 | static void sshpam_free_ctx(void *); | |
109 | static struct pam_ctxt *cleanup_ctxt; | |
110 | ||
8b32eddc | 111 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
7cac2b65 | 112 | /* |
113 | * Simulate threads with processes. | |
114 | */ | |
540d72c3 | 115 | |
116 | static int sshpam_thread_status = -1; | |
117 | static mysig_t sshpam_oldsig; | |
118 | ||
119 | static void | |
120 | sshpam_sigchld_handler(int sig) | |
121 | { | |
7e82606e | 122 | signal(SIGCHLD, SIG_DFL); |
540d72c3 | 123 | if (cleanup_ctxt == NULL) |
124 | return; /* handler called after PAM cleanup, shouldn't happen */ | |
7e82606e | 125 | if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG) |
126 | <= 0) { | |
127 | /* PAM thread has not exitted, privsep slave must have */ | |
128 | kill(cleanup_ctxt->pam_thread, SIGTERM); | |
129 | if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0) | |
130 | <= 0) | |
131 | return; /* could not wait */ | |
132 | } | |
540d72c3 | 133 | if (WIFSIGNALED(sshpam_thread_status) && |
134 | WTERMSIG(sshpam_thread_status) == SIGTERM) | |
135 | return; /* terminated by pthread_cancel */ | |
136 | if (!WIFEXITED(sshpam_thread_status)) | |
137 | fatal("PAM: authentication thread exited unexpectedly"); | |
138 | if (WEXITSTATUS(sshpam_thread_status) != 0) | |
139 | fatal("PAM: authentication thread exited uncleanly"); | |
140 | } | |
3c0ef626 | 141 | |
7cac2b65 | 142 | static void |
143 | pthread_exit(void *value __unused) | |
144 | { | |
145 | _exit(0); | |
146 | } | |
3c0ef626 | 147 | |
7cac2b65 | 148 | static int |
149 | pthread_create(sp_pthread_t *thread, const void *attr __unused, | |
150 | void *(*thread_start)(void *), void *arg) | |
151 | { | |
152 | pid_t pid; | |
153 | ||
12a403af | 154 | sshpam_thread_status = -1; |
7cac2b65 | 155 | switch ((pid = fork())) { |
156 | case -1: | |
157 | error("fork(): %s", strerror(errno)); | |
158 | return (-1); | |
159 | case 0: | |
160 | thread_start(arg); | |
161 | _exit(1); | |
162 | default: | |
163 | *thread = pid; | |
540d72c3 | 164 | sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler); |
7cac2b65 | 165 | return (0); |
166 | } | |
167 | } | |
3c0ef626 | 168 | |
7cac2b65 | 169 | static int |
170 | pthread_cancel(sp_pthread_t thread) | |
3c0ef626 | 171 | { |
540d72c3 | 172 | signal(SIGCHLD, sshpam_oldsig); |
7cac2b65 | 173 | return (kill(thread, SIGTERM)); |
3c0ef626 | 174 | } |
175 | ||
7cac2b65 | 176 | static int |
177 | pthread_join(sp_pthread_t thread, void **value __unused) | |
3c0ef626 | 178 | { |
7cac2b65 | 179 | int status; |
180 | ||
540d72c3 | 181 | if (sshpam_thread_status != -1) |
182 | return (sshpam_thread_status); | |
183 | signal(SIGCHLD, sshpam_oldsig); | |
7cac2b65 | 184 | waitpid(thread, &status, 0); |
185 | return (status); | |
3c0ef626 | 186 | } |
7cac2b65 | 187 | #endif |
188 | ||
189 | ||
29d88157 | 190 | static pam_handle_t *sshpam_handle = NULL; |
191 | static int sshpam_err = 0; | |
192 | static int sshpam_authenticated = 0; | |
29d88157 | 193 | static int sshpam_session_open = 0; |
194 | static int sshpam_cred_established = 0; | |
540d72c3 | 195 | static int sshpam_account_status = -1; |
196 | static char **sshpam_env = NULL; | |
12a403af | 197 | static Authctxt *sshpam_authctxt = NULL; |
7e82606e | 198 | static const char *sshpam_password = NULL; |
dfddba3d | 199 | static char badpw[] = "\b\n\r\177INCORRECT"; |
540d72c3 | 200 | |
201 | /* Some PAM implementations don't implement this */ | |
202 | #ifndef HAVE_PAM_GETENVLIST | |
203 | static char ** | |
204 | pam_getenvlist(pam_handle_t *pamh) | |
205 | { | |
206 | /* | |
207 | * XXX - If necessary, we can still support envrionment passing | |
208 | * for platforms without pam_getenvlist by searching for known | |
209 | * env vars (e.g. KRB5CCNAME) from the PAM environment. | |
210 | */ | |
211 | return NULL; | |
212 | } | |
213 | #endif | |
7cac2b65 | 214 | |
7e82606e | 215 | /* |
216 | * Some platforms, notably Solaris, do not enforce password complexity | |
217 | * rules during pam_chauthtok() if the real uid of the calling process | |
218 | * is 0, on the assumption that it's being called by "passwd" run by root. | |
219 | * This wraps pam_chauthtok and sets/restore the real uid so PAM will do | |
220 | * the right thing. | |
221 | */ | |
222 | #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID | |
223 | static int | |
224 | sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags) | |
225 | { | |
226 | int result; | |
227 | ||
228 | if (sshpam_authctxt == NULL) | |
229 | fatal("PAM: sshpam_authctxt not initialized"); | |
230 | if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1) | |
231 | fatal("%s: setreuid failed: %s", __func__, strerror(errno)); | |
232 | result = pam_chauthtok(pamh, flags); | |
233 | if (setreuid(0, -1) == -1) | |
234 | fatal("%s: setreuid failed: %s", __func__, strerror(errno)); | |
235 | return result; | |
236 | } | |
237 | # define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b))) | |
238 | #endif | |
239 | ||
540d72c3 | 240 | void |
7e82606e | 241 | sshpam_password_change_required(int reqd) |
540d72c3 | 242 | { |
243 | debug3("%s %d", __func__, reqd); | |
12a403af | 244 | if (sshpam_authctxt == NULL) |
245 | fatal("%s: PAM authctxt not initialized", __func__); | |
246 | sshpam_authctxt->force_pwchange = reqd; | |
540d72c3 | 247 | if (reqd) { |
248 | no_port_forwarding_flag |= 2; | |
249 | no_agent_forwarding_flag |= 2; | |
250 | no_x11_forwarding_flag |= 2; | |
251 | } else { | |
252 | no_port_forwarding_flag &= ~2; | |
253 | no_agent_forwarding_flag &= ~2; | |
254 | no_x11_forwarding_flag &= ~2; | |
255 | } | |
256 | } | |
7cac2b65 | 257 | |
540d72c3 | 258 | /* Import regular and PAM environment from subprocess */ |
259 | static void | |
260 | import_environments(Buffer *b) | |
261 | { | |
262 | char *env; | |
263 | u_int i, num_env; | |
264 | int err; | |
265 | ||
266 | debug3("PAM: %s entering", __func__); | |
267 | ||
8b32eddc | 268 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
540d72c3 | 269 | /* Import variables set by do_pam_account */ |
270 | sshpam_account_status = buffer_get_int(b); | |
7e82606e | 271 | sshpam_password_change_required(buffer_get_int(b)); |
540d72c3 | 272 | |
273 | /* Import environment from subprocess */ | |
274 | num_env = buffer_get_int(b); | |
275 | sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env)); | |
276 | debug3("PAM: num env strings %d", num_env); | |
277 | for(i = 0; i < num_env; i++) | |
278 | sshpam_env[i] = buffer_get_string(b, NULL); | |
279 | ||
280 | sshpam_env[num_env] = NULL; | |
281 | ||
282 | /* Import PAM environment from subprocess */ | |
283 | num_env = buffer_get_int(b); | |
284 | debug("PAM: num PAM env strings %d", num_env); | |
285 | for(i = 0; i < num_env; i++) { | |
286 | env = buffer_get_string(b, NULL); | |
287 | ||
288 | #ifdef HAVE_PAM_PUTENV | |
289 | /* Errors are not fatal here */ | |
290 | if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { | |
291 | error("PAM: pam_putenv: %s", | |
292 | pam_strerror(sshpam_handle, sshpam_err)); | |
293 | } | |
294 | #endif | |
295 | } | |
12a403af | 296 | #endif |
540d72c3 | 297 | } |
3c0ef626 | 298 | |
299 | /* | |
7cac2b65 | 300 | * Conversation function for authentication thread. |
3c0ef626 | 301 | */ |
7cac2b65 | 302 | static int |
7e82606e | 303 | sshpam_thread_conv(int n, struct pam_message **msg, |
7cac2b65 | 304 | struct pam_response **resp, void *data) |
3c0ef626 | 305 | { |
7cac2b65 | 306 | Buffer buffer; |
307 | struct pam_ctxt *ctxt; | |
29d88157 | 308 | struct pam_response *reply; |
7cac2b65 | 309 | int i; |
310 | ||
540d72c3 | 311 | debug3("PAM: %s entering, %d messages", __func__, n); |
29d88157 | 312 | *resp = NULL; |
313 | ||
7e82606e | 314 | if (data == NULL) { |
315 | error("PAM: conversation function passed a null context"); | |
316 | return (PAM_CONV_ERR); | |
317 | } | |
7cac2b65 | 318 | ctxt = data; |
319 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
320 | return (PAM_CONV_ERR); | |
29d88157 | 321 | |
322 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
323 | return (PAM_CONV_ERR); | |
324 | memset(reply, 0, n * sizeof(*reply)); | |
325 | ||
7cac2b65 | 326 | buffer_init(&buffer); |
327 | for (i = 0; i < n; ++i) { | |
7cac2b65 | 328 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { |
329 | case PAM_PROMPT_ECHO_OFF: | |
540d72c3 | 330 | buffer_put_cstring(&buffer, |
29d88157 | 331 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 332 | if (ssh_msg_send(ctxt->pam_csock, |
333 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
334 | goto fail; | |
335 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
336 | goto fail; | |
7cac2b65 | 337 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
338 | goto fail; | |
29d88157 | 339 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 340 | break; |
341 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 342 | buffer_put_cstring(&buffer, |
29d88157 | 343 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 344 | if (ssh_msg_send(ctxt->pam_csock, |
345 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
346 | goto fail; | |
347 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
348 | goto fail; | |
7cac2b65 | 349 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
350 | goto fail; | |
29d88157 | 351 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 352 | break; |
353 | case PAM_ERROR_MSG: | |
540d72c3 | 354 | buffer_put_cstring(&buffer, |
29d88157 | 355 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 356 | if (ssh_msg_send(ctxt->pam_csock, |
357 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
358 | goto fail; | |
7cac2b65 | 359 | break; |
360 | case PAM_TEXT_INFO: | |
540d72c3 | 361 | buffer_put_cstring(&buffer, |
29d88157 | 362 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 363 | if (ssh_msg_send(ctxt->pam_csock, |
364 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
365 | goto fail; | |
7cac2b65 | 366 | break; |
367 | default: | |
368 | goto fail; | |
3c0ef626 | 369 | } |
7cac2b65 | 370 | buffer_clear(&buffer); |
3c0ef626 | 371 | } |
7cac2b65 | 372 | buffer_free(&buffer); |
29d88157 | 373 | *resp = reply; |
7cac2b65 | 374 | return (PAM_SUCCESS); |
29d88157 | 375 | |
7cac2b65 | 376 | fail: |
29d88157 | 377 | for(i = 0; i < n; i++) { |
378 | if (reply[i].resp != NULL) | |
379 | xfree(reply[i].resp); | |
380 | } | |
381 | xfree(reply); | |
7cac2b65 | 382 | buffer_free(&buffer); |
383 | return (PAM_CONV_ERR); | |
3c0ef626 | 384 | } |
385 | ||
7cac2b65 | 386 | /* |
387 | * Authentication thread. | |
388 | */ | |
389 | static void * | |
390 | sshpam_thread(void *ctxtp) | |
3c0ef626 | 391 | { |
7cac2b65 | 392 | struct pam_ctxt *ctxt = ctxtp; |
393 | Buffer buffer; | |
394 | struct pam_conv sshpam_conv; | |
7e82606e | 395 | int flags = (options.permit_empty_passwd == 0 ? |
396 | PAM_DISALLOW_NULL_AUTHTOK : 0); | |
8b32eddc | 397 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
540d72c3 | 398 | extern char **environ; |
399 | char **env_from_pam; | |
400 | u_int i; | |
7cac2b65 | 401 | const char *pam_user; |
402 | ||
7e82606e | 403 | pam_get_item(sshpam_handle, PAM_USER, (void **)&pam_user); |
540d72c3 | 404 | environ[0] = NULL; |
7e82606e | 405 | |
406 | if (sshpam_authctxt != NULL) { | |
407 | setproctitle("%s [pam]", | |
408 | sshpam_authctxt->valid ? pam_user : "unknown"); | |
409 | } | |
7cac2b65 | 410 | #endif |
3c0ef626 | 411 | |
7cac2b65 | 412 | sshpam_conv.conv = sshpam_thread_conv; |
413 | sshpam_conv.appdata_ptr = ctxt; | |
414 | ||
12a403af | 415 | if (sshpam_authctxt == NULL) |
416 | fatal("%s: PAM authctxt not initialized", __func__); | |
417 | ||
7cac2b65 | 418 | buffer_init(&buffer); |
419 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
420 | (const void *)&sshpam_conv); | |
421 | if (sshpam_err != PAM_SUCCESS) | |
422 | goto auth_fail; | |
7e82606e | 423 | sshpam_err = pam_authenticate(sshpam_handle, flags); |
7cac2b65 | 424 | if (sshpam_err != PAM_SUCCESS) |
425 | goto auth_fail; | |
540d72c3 | 426 | |
427 | if (compat20) { | |
428 | if (!do_pam_account()) | |
429 | goto auth_fail; | |
12a403af | 430 | if (sshpam_authctxt->force_pwchange) { |
540d72c3 | 431 | sshpam_err = pam_chauthtok(sshpam_handle, |
432 | PAM_CHANGE_EXPIRED_AUTHTOK); | |
433 | if (sshpam_err != PAM_SUCCESS) | |
434 | goto auth_fail; | |
7e82606e | 435 | sshpam_password_change_required(0); |
540d72c3 | 436 | } |
437 | } | |
438 | ||
7cac2b65 | 439 | buffer_put_cstring(&buffer, "OK"); |
540d72c3 | 440 | |
8b32eddc | 441 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
540d72c3 | 442 | /* Export variables set by do_pam_account */ |
443 | buffer_put_int(&buffer, sshpam_account_status); | |
12a403af | 444 | buffer_put_int(&buffer, sshpam_authctxt->force_pwchange); |
540d72c3 | 445 | |
446 | /* Export any environment strings set in child */ | |
447 | for(i = 0; environ[i] != NULL; i++) | |
448 | ; /* Count */ | |
449 | buffer_put_int(&buffer, i); | |
450 | for(i = 0; environ[i] != NULL; i++) | |
451 | buffer_put_cstring(&buffer, environ[i]); | |
452 | ||
453 | /* Export any environment strings set by PAM in child */ | |
454 | env_from_pam = pam_getenvlist(sshpam_handle); | |
455 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
456 | ; /* Count */ | |
457 | buffer_put_int(&buffer, i); | |
458 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
459 | buffer_put_cstring(&buffer, env_from_pam[i]); | |
8b32eddc | 460 | #endif /* UNSUPPORTED_POSIX_THREADS_HACK */ |
540d72c3 | 461 | |
462 | /* XXX - can't do much about an error here */ | |
7cac2b65 | 463 | ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); |
464 | buffer_free(&buffer); | |
465 | pthread_exit(NULL); | |
466 | ||
467 | auth_fail: | |
468 | buffer_put_cstring(&buffer, | |
469 | pam_strerror(sshpam_handle, sshpam_err)); | |
540d72c3 | 470 | /* XXX - can't do much about an error here */ |
7cac2b65 | 471 | ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); |
472 | buffer_free(&buffer); | |
473 | pthread_exit(NULL); | |
540d72c3 | 474 | |
7cac2b65 | 475 | return (NULL); /* Avoid warning for non-pthread case */ |
476 | } | |
3c0ef626 | 477 | |
540d72c3 | 478 | void |
479 | sshpam_thread_cleanup(void) | |
7cac2b65 | 480 | { |
540d72c3 | 481 | struct pam_ctxt *ctxt = cleanup_ctxt; |
482 | ||
483 | debug3("PAM: %s entering", __func__); | |
484 | if (ctxt != NULL && ctxt->pam_thread != 0) { | |
485 | pthread_cancel(ctxt->pam_thread); | |
486 | pthread_join(ctxt->pam_thread, NULL); | |
487 | close(ctxt->pam_psock); | |
488 | close(ctxt->pam_csock); | |
489 | memset(ctxt, 0, sizeof(*ctxt)); | |
490 | cleanup_ctxt = NULL; | |
491 | } | |
3c0ef626 | 492 | } |
493 | ||
7cac2b65 | 494 | static int |
7e82606e | 495 | sshpam_null_conv(int n, struct pam_message **msg, |
7cac2b65 | 496 | struct pam_response **resp, void *data) |
3c0ef626 | 497 | { |
540d72c3 | 498 | debug3("PAM: %s entering, %d messages", __func__, n); |
7cac2b65 | 499 | return (PAM_CONV_ERR); |
500 | } | |
3c0ef626 | 501 | |
7cac2b65 | 502 | static struct pam_conv null_conv = { sshpam_null_conv, NULL }; |
3c0ef626 | 503 | |
dfddba3d | 504 | static int |
505 | sshpam_store_conv(int n, struct pam_message **msg, | |
506 | struct pam_response **resp, void *data) | |
507 | { | |
508 | struct pam_response *reply; | |
509 | int i; | |
510 | size_t len; | |
511 | ||
512 | debug3("PAM: %s called with %d messages", __func__, n); | |
513 | *resp = NULL; | |
514 | ||
515 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
516 | return (PAM_CONV_ERR); | |
517 | ||
518 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
519 | return (PAM_CONV_ERR); | |
520 | memset(reply, 0, n * sizeof(*reply)); | |
521 | ||
522 | for (i = 0; i < n; ++i) { | |
523 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
524 | case PAM_ERROR_MSG: | |
525 | case PAM_TEXT_INFO: | |
526 | len = strlen(PAM_MSG_MEMBER(msg, i, msg)); | |
527 | buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len); | |
528 | buffer_append(&loginmsg, "\n", 1 ); | |
529 | reply[i].resp_retcode = PAM_SUCCESS; | |
530 | break; | |
531 | default: | |
532 | goto fail; | |
533 | } | |
534 | } | |
535 | *resp = reply; | |
536 | return (PAM_SUCCESS); | |
537 | ||
538 | fail: | |
539 | for(i = 0; i < n; i++) { | |
540 | if (reply[i].resp != NULL) | |
541 | xfree(reply[i].resp); | |
542 | } | |
543 | xfree(reply); | |
544 | return (PAM_CONV_ERR); | |
545 | } | |
546 | ||
547 | static struct pam_conv store_conv = { sshpam_store_conv, NULL }; | |
548 | ||
540d72c3 | 549 | void |
550 | sshpam_cleanup(void) | |
7cac2b65 | 551 | { |
7cac2b65 | 552 | debug("PAM: cleanup"); |
29d88157 | 553 | if (sshpam_handle == NULL) |
554 | return; | |
7cac2b65 | 555 | pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); |
556 | if (sshpam_cred_established) { | |
557 | pam_setcred(sshpam_handle, PAM_DELETE_CRED); | |
558 | sshpam_cred_established = 0; | |
559 | } | |
560 | if (sshpam_session_open) { | |
561 | pam_close_session(sshpam_handle, PAM_SILENT); | |
562 | sshpam_session_open = 0; | |
563 | } | |
540d72c3 | 564 | sshpam_authenticated = 0; |
7cac2b65 | 565 | pam_end(sshpam_handle, sshpam_err); |
566 | sshpam_handle = NULL; | |
567 | } | |
3c0ef626 | 568 | |
7cac2b65 | 569 | static int |
12a403af | 570 | sshpam_init(Authctxt *authctxt) |
7cac2b65 | 571 | { |
7cac2b65 | 572 | extern char *__progname; |
12a403af | 573 | const char *pam_rhost, *pam_user, *user = authctxt->user; |
7cac2b65 | 574 | |
575 | if (sshpam_handle != NULL) { | |
576 | /* We already have a PAM context; check if the user matches */ | |
577 | sshpam_err = pam_get_item(sshpam_handle, | |
7e82606e | 578 | PAM_USER, (void **)&pam_user); |
7cac2b65 | 579 | if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) |
580 | return (0); | |
7cac2b65 | 581 | pam_end(sshpam_handle, sshpam_err); |
582 | sshpam_handle = NULL; | |
583 | } | |
584 | debug("PAM: initializing for \"%s\"", user); | |
585 | sshpam_err = | |
dfddba3d | 586 | pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle); |
12a403af | 587 | sshpam_authctxt = authctxt; |
588 | ||
7cac2b65 | 589 | if (sshpam_err != PAM_SUCCESS) { |
590 | pam_end(sshpam_handle, sshpam_err); | |
591 | sshpam_handle = NULL; | |
592 | return (-1); | |
3c0ef626 | 593 | } |
7cac2b65 | 594 | pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); |
595 | debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); | |
596 | sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); | |
597 | if (sshpam_err != PAM_SUCCESS) { | |
598 | pam_end(sshpam_handle, sshpam_err); | |
599 | sshpam_handle = NULL; | |
600 | return (-1); | |
601 | } | |
602 | #ifdef PAM_TTY_KLUDGE | |
540d72c3 | 603 | /* |
604 | * Some silly PAM modules (e.g. pam_time) require a TTY to operate. | |
605 | * sshd doesn't set the tty until too late in the auth process and | |
7cac2b65 | 606 | * may not even set one (for tty-less connections) |
540d72c3 | 607 | */ |
7cac2b65 | 608 | debug("PAM: setting PAM_TTY to \"ssh\""); |
609 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); | |
610 | if (sshpam_err != PAM_SUCCESS) { | |
611 | pam_end(sshpam_handle, sshpam_err); | |
612 | sshpam_handle = NULL; | |
613 | return (-1); | |
614 | } | |
615 | #endif | |
7cac2b65 | 616 | return (0); |
3c0ef626 | 617 | } |
618 | ||
7cac2b65 | 619 | static void * |
620 | sshpam_init_ctx(Authctxt *authctxt) | |
3c0ef626 | 621 | { |
7cac2b65 | 622 | struct pam_ctxt *ctxt; |
623 | int socks[2]; | |
3c0ef626 | 624 | |
540d72c3 | 625 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 626 | /* Refuse to start if we don't have PAM enabled */ |
627 | if (!options.use_pam) | |
628 | return NULL; | |
3c0ef626 | 629 | |
7cac2b65 | 630 | /* Initialize PAM */ |
12a403af | 631 | if (sshpam_init(authctxt) == -1) { |
7cac2b65 | 632 | error("PAM: initialization failed"); |
633 | return (NULL); | |
3c0ef626 | 634 | } |
635 | ||
7cac2b65 | 636 | ctxt = xmalloc(sizeof *ctxt); |
540d72c3 | 637 | memset(ctxt, 0, sizeof(*ctxt)); |
638 | ||
7cac2b65 | 639 | /* Start the authentication thread */ |
640 | if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { | |
641 | error("PAM: failed create sockets: %s", strerror(errno)); | |
642 | xfree(ctxt); | |
643 | return (NULL); | |
644 | } | |
645 | ctxt->pam_psock = socks[0]; | |
646 | ctxt->pam_csock = socks[1]; | |
647 | if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { | |
648 | error("PAM: failed to start authentication thread: %s", | |
649 | strerror(errno)); | |
650 | close(socks[0]); | |
651 | close(socks[1]); | |
652 | xfree(ctxt); | |
653 | return (NULL); | |
654 | } | |
540d72c3 | 655 | cleanup_ctxt = ctxt; |
7cac2b65 | 656 | return (ctxt); |
657 | } | |
658 | ||
659 | static int | |
660 | sshpam_query(void *ctx, char **name, char **info, | |
661 | u_int *num, char ***prompts, u_int **echo_on) | |
662 | { | |
663 | Buffer buffer; | |
664 | struct pam_ctxt *ctxt = ctx; | |
665 | size_t plen; | |
666 | u_char type; | |
667 | char *msg; | |
dfddba3d | 668 | size_t len, mlen; |
7cac2b65 | 669 | |
540d72c3 | 670 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 671 | buffer_init(&buffer); |
672 | *name = xstrdup(""); | |
673 | *info = xstrdup(""); | |
674 | *prompts = xmalloc(sizeof(char *)); | |
675 | **prompts = NULL; | |
676 | plen = 0; | |
677 | *echo_on = xmalloc(sizeof(u_int)); | |
678 | while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { | |
679 | type = buffer_get_char(&buffer); | |
680 | msg = buffer_get_string(&buffer, NULL); | |
dfddba3d | 681 | mlen = strlen(msg); |
7cac2b65 | 682 | switch (type) { |
683 | case PAM_PROMPT_ECHO_ON: | |
684 | case PAM_PROMPT_ECHO_OFF: | |
685 | *num = 1; | |
dfddba3d | 686 | len = plen + mlen + 1; |
7cac2b65 | 687 | **prompts = xrealloc(**prompts, len); |
dfddba3d | 688 | strlcpy(**prompts + plen, msg, len - plen); |
689 | plen += mlen; | |
7cac2b65 | 690 | **echo_on = (type == PAM_PROMPT_ECHO_ON); |
691 | xfree(msg); | |
692 | return (0); | |
693 | case PAM_ERROR_MSG: | |
694 | case PAM_TEXT_INFO: | |
695 | /* accumulate messages */ | |
dfddba3d | 696 | len = plen + mlen + 2; |
7cac2b65 | 697 | **prompts = xrealloc(**prompts, len); |
dfddba3d | 698 | strlcpy(**prompts + plen, msg, len - plen); |
699 | plen += mlen; | |
700 | strlcat(**prompts + plen, "\n", len - plen); | |
701 | plen++; | |
7cac2b65 | 702 | xfree(msg); |
3c0ef626 | 703 | break; |
7cac2b65 | 704 | case PAM_SUCCESS: |
705 | case PAM_AUTH_ERR: | |
706 | if (**prompts != NULL) { | |
707 | /* drain any accumulated messages */ | |
540d72c3 | 708 | debug("PAM: %s", **prompts); |
709 | buffer_append(&loginmsg, **prompts, | |
710 | strlen(**prompts)); | |
7cac2b65 | 711 | xfree(**prompts); |
712 | **prompts = NULL; | |
713 | } | |
714 | if (type == PAM_SUCCESS) { | |
dfddba3d | 715 | if (!sshpam_authctxt->valid || |
716 | (sshpam_authctxt->pw->pw_uid == 0 && | |
717 | options.permit_root_login != PERMIT_YES)) | |
718 | fatal("Internal error: PAM auth " | |
719 | "succeeded when it should have " | |
720 | "failed"); | |
540d72c3 | 721 | import_environments(&buffer); |
7cac2b65 | 722 | *num = 0; |
723 | **echo_on = 0; | |
724 | ctxt->pam_done = 1; | |
725 | xfree(msg); | |
726 | return (0); | |
727 | } | |
12a403af | 728 | error("PAM: %s for %s%.100s from %.100s", msg, |
729 | sshpam_authctxt->valid ? "" : "illegal user ", | |
730 | sshpam_authctxt->user, | |
731 | get_remote_name_or_ip(utmp_len, options.use_dns)); | |
540d72c3 | 732 | /* FALLTHROUGH */ |
3c0ef626 | 733 | default: |
7cac2b65 | 734 | *num = 0; |
735 | **echo_on = 0; | |
736 | xfree(msg); | |
737 | ctxt->pam_done = -1; | |
738 | return (-1); | |
739 | } | |
3c0ef626 | 740 | } |
7cac2b65 | 741 | return (-1); |
3c0ef626 | 742 | } |
743 | ||
7cac2b65 | 744 | /* XXX - see also comment in auth-chall.c:verify_response */ |
745 | static int | |
746 | sshpam_respond(void *ctx, u_int num, char **resp) | |
3c0ef626 | 747 | { |
7cac2b65 | 748 | Buffer buffer; |
749 | struct pam_ctxt *ctxt = ctx; | |
750 | ||
540d72c3 | 751 | debug2("PAM: %s entering, %d responses", __func__, num); |
7cac2b65 | 752 | switch (ctxt->pam_done) { |
753 | case 1: | |
754 | sshpam_authenticated = 1; | |
755 | return (0); | |
756 | case 0: | |
757 | break; | |
758 | default: | |
759 | return (-1); | |
3c0ef626 | 760 | } |
7cac2b65 | 761 | if (num != 1) { |
762 | error("PAM: expected one response, got %u", num); | |
763 | return (-1); | |
764 | } | |
765 | buffer_init(&buffer); | |
dfddba3d | 766 | if (sshpam_authctxt->valid && |
767 | (sshpam_authctxt->pw->pw_uid != 0 || | |
768 | options.permit_root_login == PERMIT_YES)) | |
769 | buffer_put_cstring(&buffer, *resp); | |
770 | else | |
771 | buffer_put_cstring(&buffer, badpw); | |
540d72c3 | 772 | if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { |
773 | buffer_free(&buffer); | |
774 | return (-1); | |
775 | } | |
7cac2b65 | 776 | buffer_free(&buffer); |
777 | return (1); | |
3c0ef626 | 778 | } |
779 | ||
7cac2b65 | 780 | static void |
781 | sshpam_free_ctx(void *ctxtp) | |
3c0ef626 | 782 | { |
7cac2b65 | 783 | struct pam_ctxt *ctxt = ctxtp; |
350391c5 | 784 | |
540d72c3 | 785 | debug3("PAM: %s entering", __func__); |
786 | sshpam_thread_cleanup(); | |
7cac2b65 | 787 | xfree(ctxt); |
788 | /* | |
789 | * We don't call sshpam_cleanup() here because we may need the PAM | |
790 | * handle at a later stage, e.g. when setting up a session. It's | |
791 | * still on the cleanup list, so pam_end() *will* be called before | |
792 | * the server process terminates. | |
793 | */ | |
3c0ef626 | 794 | } |
795 | ||
7cac2b65 | 796 | KbdintDevice sshpam_device = { |
797 | "pam", | |
798 | sshpam_init_ctx, | |
799 | sshpam_query, | |
800 | sshpam_respond, | |
801 | sshpam_free_ctx | |
802 | }; | |
803 | ||
804 | KbdintDevice mm_sshpam_device = { | |
805 | "pam", | |
806 | mm_sshpam_init_ctx, | |
807 | mm_sshpam_query, | |
808 | mm_sshpam_respond, | |
809 | mm_sshpam_free_ctx | |
810 | }; | |
3c0ef626 | 811 | |
812 | /* | |
7cac2b65 | 813 | * This replaces auth-pam.c |
3c0ef626 | 814 | */ |
7cac2b65 | 815 | void |
12a403af | 816 | start_pam(Authctxt *authctxt) |
3c0ef626 | 817 | { |
7cac2b65 | 818 | if (!options.use_pam) |
819 | fatal("PAM: initialisation requested when UsePAM=no"); | |
820 | ||
12a403af | 821 | if (sshpam_init(authctxt) == -1) |
7cac2b65 | 822 | fatal("PAM: initialisation failed"); |
3c0ef626 | 823 | } |
824 | ||
7cac2b65 | 825 | void |
826 | finish_pam(void) | |
3c0ef626 | 827 | { |
540d72c3 | 828 | sshpam_cleanup(); |
3c0ef626 | 829 | } |
830 | ||
7cac2b65 | 831 | u_int |
832 | do_pam_account(void) | |
3c0ef626 | 833 | { |
dfddba3d | 834 | debug("%s: called", __func__); |
540d72c3 | 835 | if (sshpam_account_status != -1) |
836 | return (sshpam_account_status); | |
837 | ||
7cac2b65 | 838 | sshpam_err = pam_acct_mgmt(sshpam_handle, 0); |
dfddba3d | 839 | debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err, |
840 | pam_strerror(sshpam_handle, sshpam_err)); | |
7cac2b65 | 841 | |
540d72c3 | 842 | if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) { |
843 | sshpam_account_status = 0; | |
844 | return (sshpam_account_status); | |
7cac2b65 | 845 | } |
3c0ef626 | 846 | |
540d72c3 | 847 | if (sshpam_err == PAM_NEW_AUTHTOK_REQD) |
7e82606e | 848 | sshpam_password_change_required(1); |
3c0ef626 | 849 | |
540d72c3 | 850 | sshpam_account_status = 1; |
851 | return (sshpam_account_status); | |
7cac2b65 | 852 | } |
3c0ef626 | 853 | |
7cac2b65 | 854 | void |
855 | do_pam_set_tty(const char *tty) | |
856 | { | |
857 | if (tty != NULL) { | |
858 | debug("PAM: setting PAM_TTY to \"%s\"", tty); | |
859 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); | |
860 | if (sshpam_err != PAM_SUCCESS) | |
861 | fatal("PAM: failed to set PAM_TTY: %s", | |
862 | pam_strerror(sshpam_handle, sshpam_err)); | |
863 | } | |
864 | } | |
3c0ef626 | 865 | |
7cac2b65 | 866 | void |
867 | do_pam_setcred(int init) | |
868 | { | |
869 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
dfddba3d | 870 | (const void *)&store_conv); |
7cac2b65 | 871 | if (sshpam_err != PAM_SUCCESS) |
872 | fatal("PAM: failed to set PAM_CONV: %s", | |
873 | pam_strerror(sshpam_handle, sshpam_err)); | |
874 | if (init) { | |
875 | debug("PAM: establishing credentials"); | |
876 | sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); | |
877 | } else { | |
878 | debug("PAM: reinitializing credentials"); | |
879 | sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); | |
880 | } | |
881 | if (sshpam_err == PAM_SUCCESS) { | |
882 | sshpam_cred_established = 1; | |
883 | return; | |
884 | } | |
885 | if (sshpam_authenticated) | |
886 | fatal("PAM: pam_setcred(): %s", | |
887 | pam_strerror(sshpam_handle, sshpam_err)); | |
888 | else | |
889 | debug("PAM: pam_setcred(): %s", | |
890 | pam_strerror(sshpam_handle, sshpam_err)); | |
3c0ef626 | 891 | } |
892 | ||
7cac2b65 | 893 | static int |
7e82606e | 894 | sshpam_tty_conv(int n, struct pam_message **msg, |
7cac2b65 | 895 | struct pam_response **resp, void *data) |
23987cb8 | 896 | { |
7cac2b65 | 897 | char input[PAM_MAX_MSG_SIZE]; |
29d88157 | 898 | struct pam_response *reply; |
23987cb8 | 899 | int i; |
900 | ||
540d72c3 | 901 | debug3("PAM: %s called with %d messages", __func__, n); |
902 | ||
29d88157 | 903 | *resp = NULL; |
904 | ||
540d72c3 | 905 | if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) |
7cac2b65 | 906 | return (PAM_CONV_ERR); |
29d88157 | 907 | |
908 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
909 | return (PAM_CONV_ERR); | |
910 | memset(reply, 0, n * sizeof(*reply)); | |
911 | ||
7cac2b65 | 912 | for (i = 0; i < n; ++i) { |
913 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
914 | case PAM_PROMPT_ECHO_OFF: | |
29d88157 | 915 | reply[i].resp = |
540d72c3 | 916 | read_passphrase(PAM_MSG_MEMBER(msg, i, msg), |
7cac2b65 | 917 | RP_ALLOW_STDIN); |
29d88157 | 918 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 919 | break; |
920 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 921 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
7cac2b65 | 922 | fgets(input, sizeof input, stdin); |
7e82606e | 923 | if ((reply[i].resp = strdup(input)) == NULL) |
924 | goto fail; | |
29d88157 | 925 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 926 | break; |
927 | case PAM_ERROR_MSG: | |
928 | case PAM_TEXT_INFO: | |
540d72c3 | 929 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
29d88157 | 930 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 931 | break; |
932 | default: | |
933 | goto fail; | |
934 | } | |
23987cb8 | 935 | } |
29d88157 | 936 | *resp = reply; |
7cac2b65 | 937 | return (PAM_SUCCESS); |
29d88157 | 938 | |
7cac2b65 | 939 | fail: |
29d88157 | 940 | for(i = 0; i < n; i++) { |
941 | if (reply[i].resp != NULL) | |
942 | xfree(reply[i].resp); | |
943 | } | |
944 | xfree(reply); | |
7cac2b65 | 945 | return (PAM_CONV_ERR); |
23987cb8 | 946 | } |
947 | ||
7e82606e | 948 | static struct pam_conv tty_conv = { sshpam_tty_conv, NULL }; |
540d72c3 | 949 | |
7cac2b65 | 950 | /* |
951 | * XXX this should be done in the authentication phase, but ssh1 doesn't | |
952 | * support that | |
953 | */ | |
954 | void | |
955 | do_pam_chauthtok(void) | |
956 | { | |
7cac2b65 | 957 | if (use_privsep) |
958 | fatal("Password expired (unable to change with privsep)"); | |
959 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
540d72c3 | 960 | (const void *)&tty_conv); |
7cac2b65 | 961 | if (sshpam_err != PAM_SUCCESS) |
962 | fatal("PAM: failed to set PAM_CONV: %s", | |
963 | pam_strerror(sshpam_handle, sshpam_err)); | |
964 | debug("PAM: changing password"); | |
965 | sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); | |
966 | if (sshpam_err != PAM_SUCCESS) | |
967 | fatal("PAM: pam_chauthtok(): %s", | |
968 | pam_strerror(sshpam_handle, sshpam_err)); | |
969 | } | |
970 | ||
540d72c3 | 971 | void |
972 | do_pam_session(void) | |
973 | { | |
974 | debug3("PAM: opening session"); | |
975 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
976 | (const void *)&store_conv); | |
977 | if (sshpam_err != PAM_SUCCESS) | |
978 | fatal("PAM: failed to set PAM_CONV: %s", | |
979 | pam_strerror(sshpam_handle, sshpam_err)); | |
980 | sshpam_err = pam_open_session(sshpam_handle, 0); | |
dfddba3d | 981 | if (sshpam_err == PAM_SUCCESS) |
982 | sshpam_session_open = 1; | |
983 | else { | |
984 | sshpam_session_open = 0; | |
985 | disable_forwarding(); | |
986 | error("PAM: pam_open_session(): %s", | |
540d72c3 | 987 | pam_strerror(sshpam_handle, sshpam_err)); |
dfddba3d | 988 | } |
989 | ||
990 | } | |
991 | ||
992 | int | |
993 | is_pam_session_open(void) | |
994 | { | |
995 | return sshpam_session_open; | |
540d72c3 | 996 | } |
997 | ||
998 | /* | |
7cac2b65 | 999 | * Set a PAM environment string. We need to do this so that the session |
5598e598 | 1000 | * modules can handle things like Kerberos/GSI credentials that appear |
1001 | * during the ssh authentication process. | |
1002 | */ | |
7cac2b65 | 1003 | int |
540d72c3 | 1004 | do_pam_putenv(char *name, char *value) |
7cac2b65 | 1005 | { |
1006 | int ret = 1; | |
540d72c3 | 1007 | #ifdef HAVE_PAM_PUTENV |
5598e598 | 1008 | char *compound; |
7cac2b65 | 1009 | size_t len; |
905081a4 | 1010 | |
7cac2b65 | 1011 | len = strlen(name) + strlen(value) + 2; |
1012 | compound = xmalloc(len); | |
1013 | ||
1014 | snprintf(compound, len, "%s=%s", name, value); | |
1015 | ret = pam_putenv(sshpam_handle, compound); | |
1016 | xfree(compound); | |
905081a4 | 1017 | #endif |
7cac2b65 | 1018 | |
1019 | return (ret); | |
5598e598 | 1020 | } |
1021 | ||
540d72c3 | 1022 | char ** |
1023 | fetch_pam_child_environment(void) | |
3c0ef626 | 1024 | { |
540d72c3 | 1025 | return sshpam_env; |
3c0ef626 | 1026 | } |
1027 | ||
7cac2b65 | 1028 | char ** |
1029 | fetch_pam_environment(void) | |
3c0ef626 | 1030 | { |
7cac2b65 | 1031 | return (pam_getenvlist(sshpam_handle)); |
7cac2b65 | 1032 | } |
3c0ef626 | 1033 | |
7cac2b65 | 1034 | void |
1035 | free_pam_environment(char **env) | |
1036 | { | |
1037 | char **envp; | |
3c0ef626 | 1038 | |
7cac2b65 | 1039 | if (env == NULL) |
1040 | return; | |
3c0ef626 | 1041 | |
7cac2b65 | 1042 | for (envp = env; *envp; envp++) |
1043 | xfree(*envp); | |
1044 | xfree(env); | |
3c0ef626 | 1045 | } |
1046 | ||
7e82606e | 1047 | /* |
1048 | * "Blind" conversation function for password authentication. Assumes that | |
1049 | * echo-off prompts are for the password and stores messages for later | |
1050 | * display. | |
1051 | */ | |
1052 | static int | |
1053 | sshpam_passwd_conv(int n, struct pam_message **msg, | |
1054 | struct pam_response **resp, void *data) | |
1055 | { | |
1056 | struct pam_response *reply; | |
1057 | int i; | |
1058 | size_t len; | |
1059 | ||
1060 | debug3("PAM: %s called with %d messages", __func__, n); | |
1061 | ||
1062 | *resp = NULL; | |
1063 | ||
1064 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
1065 | return (PAM_CONV_ERR); | |
1066 | ||
1067 | if ((reply = malloc(n * sizeof(*reply))) == NULL) | |
1068 | return (PAM_CONV_ERR); | |
1069 | memset(reply, 0, n * sizeof(*reply)); | |
1070 | ||
1071 | for (i = 0; i < n; ++i) { | |
1072 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
1073 | case PAM_PROMPT_ECHO_OFF: | |
1074 | if (sshpam_password == NULL) | |
1075 | goto fail; | |
1076 | if ((reply[i].resp = strdup(sshpam_password)) == NULL) | |
1077 | goto fail; | |
1078 | reply[i].resp_retcode = PAM_SUCCESS; | |
1079 | break; | |
1080 | case PAM_ERROR_MSG: | |
1081 | case PAM_TEXT_INFO: | |
1082 | len = strlen(PAM_MSG_MEMBER(msg, i, msg)); | |
1083 | if (len > 0) { | |
1084 | buffer_append(&loginmsg, | |
1085 | PAM_MSG_MEMBER(msg, i, msg), len); | |
1086 | buffer_append(&loginmsg, "\n", 1); | |
1087 | } | |
1088 | if ((reply[i].resp = strdup("")) == NULL) | |
1089 | goto fail; | |
1090 | reply[i].resp_retcode = PAM_SUCCESS; | |
1091 | break; | |
1092 | default: | |
1093 | goto fail; | |
1094 | } | |
1095 | } | |
1096 | *resp = reply; | |
1097 | return (PAM_SUCCESS); | |
1098 | ||
1099 | fail: | |
1100 | for(i = 0; i < n; i++) { | |
1101 | if (reply[i].resp != NULL) | |
1102 | xfree(reply[i].resp); | |
1103 | } | |
1104 | xfree(reply); | |
1105 | return (PAM_CONV_ERR); | |
1106 | } | |
1107 | ||
1108 | static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL }; | |
1109 | ||
1110 | /* | |
1111 | * Attempt password authentication via PAM | |
1112 | */ | |
1113 | int | |
1114 | sshpam_auth_passwd(Authctxt *authctxt, const char *password) | |
1115 | { | |
1116 | int flags = (options.permit_empty_passwd == 0 ? | |
1117 | PAM_DISALLOW_NULL_AUTHTOK : 0); | |
7e82606e | 1118 | |
1119 | if (!options.use_pam || sshpam_handle == NULL) | |
1120 | fatal("PAM: %s called when PAM disabled or failed to " | |
1121 | "initialise.", __func__); | |
1122 | ||
1123 | sshpam_password = password; | |
1124 | sshpam_authctxt = authctxt; | |
1125 | ||
1126 | /* | |
1127 | * If the user logging in is invalid, or is root but is not permitted | |
1128 | * by PermitRootLogin, use an invalid password to prevent leaking | |
1129 | * information via timing (eg if the PAM config has a delay on fail). | |
1130 | */ | |
1131 | if (!authctxt->valid || (authctxt->pw->pw_uid == 0 && | |
1132 | options.permit_root_login != PERMIT_YES)) | |
1133 | sshpam_password = badpw; | |
1134 | ||
1135 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
1136 | (const void *)&passwd_conv); | |
1137 | if (sshpam_err != PAM_SUCCESS) | |
1138 | fatal("PAM: %s: failed to set PAM_CONV: %s", __func__, | |
1139 | pam_strerror(sshpam_handle, sshpam_err)); | |
1140 | ||
1141 | sshpam_err = pam_authenticate(sshpam_handle, flags); | |
1142 | sshpam_password = NULL; | |
1143 | if (sshpam_err == PAM_SUCCESS && authctxt->valid) { | |
1144 | debug("PAM: password authentication accepted for %.100s", | |
1145 | authctxt->user); | |
1146 | return 1; | |
1147 | } else { | |
1148 | debug("PAM: password authentication failed for %.100s: %s", | |
1149 | authctxt->valid ? authctxt->user : "an illegal user", | |
1150 | pam_strerror(sshpam_handle, sshpam_err)); | |
1151 | return 0; | |
1152 | } | |
1153 | } | |
3c0ef626 | 1154 | #endif /* USE_PAM */ |