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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> | |
d037a8b0 | 33 | * Copyright (c) 2003,2004,2006 Darren Tucker <dtucker@zip.com.au> |
7e82606e | 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" |
30460aeb | 50 | |
51 | #include <sys/types.h> | |
52 | #include <sys/stat.h> | |
53 | #include <sys/wait.h> | |
54 | ||
55 | #include <errno.h> | |
56 | #include <signal.h> | |
57 | #include <stdarg.h> | |
58 | #include <string.h> | |
59 | #include <unistd.h> | |
3c0ef626 | 60 | |
61 | #ifdef USE_PAM | |
540d72c3 | 62 | #if defined(HAVE_SECURITY_PAM_APPL_H) |
7cac2b65 | 63 | #include <security/pam_appl.h> |
540d72c3 | 64 | #elif defined (HAVE_PAM_PAM_APPL_H) |
65 | #include <pam/pam_appl.h> | |
66 | #endif | |
7cac2b65 | 67 | |
2ce0bfe4 | 68 | /* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */ |
69 | #ifdef PAM_SUN_CODEBASE | |
70 | # define sshpam_const /* Solaris, HP-UX, AIX */ | |
71 | #else | |
72 | # define sshpam_const const /* LinuxPAM, OpenPAM */ | |
73 | #endif | |
74 | ||
30460aeb | 75 | /* Ambiguity in spec: is it an array of pointers or a pointer to an array? */ |
76 | #ifdef PAM_SUN_CODEBASE | |
77 | # define PAM_MSG_MEMBER(msg, n, member) ((*(msg))[(n)].member) | |
78 | #else | |
79 | # define PAM_MSG_MEMBER(msg, n, member) ((msg)[(n)]->member) | |
80 | #endif | |
81 | ||
82 | #include "xmalloc.h" | |
83 | #include "buffer.h" | |
84 | #include "key.h" | |
85 | #include "hostfile.h" | |
350391c5 | 86 | #include "auth.h" |
3c0ef626 | 87 | #include "auth-pam.h" |
3c0ef626 | 88 | #include "canohost.h" |
7cac2b65 | 89 | #include "log.h" |
7cac2b65 | 90 | #include "msg.h" |
91 | #include "packet.h" | |
7e82606e | 92 | #include "misc.h" |
7cac2b65 | 93 | #include "servconf.h" |
94 | #include "ssh2.h" | |
7cac2b65 | 95 | #include "auth-options.h" |
30460aeb | 96 | #ifdef GSSAPI |
97 | #include "ssh-gss.h" | |
98 | #endif | |
99 | #include "monitor_wrap.h" | |
3c0ef626 | 100 | |
7cac2b65 | 101 | extern ServerOptions options; |
540d72c3 | 102 | extern Buffer loginmsg; |
103 | extern int compat20; | |
12a403af | 104 | extern u_int utmp_len; |
d03f4262 | 105 | |
8b32eddc | 106 | /* so we don't silently change behaviour */ |
7cac2b65 | 107 | #ifdef USE_POSIX_THREADS |
8b32eddc | 108 | # error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK" |
109 | #endif | |
110 | ||
111 | /* | |
112 | * Formerly known as USE_POSIX_THREADS, using this is completely unsupported | |
113 | * and generally a bad idea. Use at own risk and do not expect support if | |
114 | * this breaks. | |
115 | */ | |
116 | #ifdef UNSUPPORTED_POSIX_THREADS_HACK | |
7cac2b65 | 117 | #include <pthread.h> |
118 | /* | |
540d72c3 | 119 | * Avoid namespace clash when *not* using pthreads for systems *with* |
120 | * pthreads, which unconditionally define pthread_t via sys/types.h | |
7cac2b65 | 121 | * (e.g. Linux) |
122 | */ | |
540d72c3 | 123 | typedef pthread_t sp_pthread_t; |
7cac2b65 | 124 | #else |
540d72c3 | 125 | typedef pid_t sp_pthread_t; |
126 | #endif | |
127 | ||
128 | struct pam_ctxt { | |
129 | sp_pthread_t pam_thread; | |
130 | int pam_psock; | |
131 | int pam_csock; | |
132 | int pam_done; | |
133 | }; | |
134 | ||
135 | static void sshpam_free_ctx(void *); | |
136 | static struct pam_ctxt *cleanup_ctxt; | |
137 | ||
8b32eddc | 138 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
7cac2b65 | 139 | /* |
140 | * Simulate threads with processes. | |
141 | */ | |
540d72c3 | 142 | |
143 | static int sshpam_thread_status = -1; | |
144 | static mysig_t sshpam_oldsig; | |
145 | ||
2ce0bfe4 | 146 | static void |
540d72c3 | 147 | sshpam_sigchld_handler(int sig) |
148 | { | |
7e82606e | 149 | signal(SIGCHLD, SIG_DFL); |
540d72c3 | 150 | if (cleanup_ctxt == NULL) |
151 | return; /* handler called after PAM cleanup, shouldn't happen */ | |
7e82606e | 152 | if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG) |
2ce0bfe4 | 153 | <= 0) { |
7e82606e | 154 | /* PAM thread has not exitted, privsep slave must have */ |
155 | kill(cleanup_ctxt->pam_thread, SIGTERM); | |
156 | if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0) | |
157 | <= 0) | |
158 | return; /* could not wait */ | |
159 | } | |
540d72c3 | 160 | if (WIFSIGNALED(sshpam_thread_status) && |
161 | WTERMSIG(sshpam_thread_status) == SIGTERM) | |
162 | return; /* terminated by pthread_cancel */ | |
163 | if (!WIFEXITED(sshpam_thread_status)) | |
fa0f0f45 | 164 | sigdie("PAM: authentication thread exited unexpectedly"); |
540d72c3 | 165 | if (WEXITSTATUS(sshpam_thread_status) != 0) |
fa0f0f45 | 166 | sigdie("PAM: authentication thread exited uncleanly"); |
540d72c3 | 167 | } |
3c0ef626 | 168 | |
30460aeb | 169 | /* ARGSUSED */ |
7cac2b65 | 170 | static void |
30460aeb | 171 | pthread_exit(void *value) |
7cac2b65 | 172 | { |
173 | _exit(0); | |
174 | } | |
3c0ef626 | 175 | |
30460aeb | 176 | /* ARGSUSED */ |
7cac2b65 | 177 | static int |
30460aeb | 178 | pthread_create(sp_pthread_t *thread, const void *attr, |
7cac2b65 | 179 | void *(*thread_start)(void *), void *arg) |
180 | { | |
181 | pid_t pid; | |
2ce0bfe4 | 182 | struct pam_ctxt *ctx = arg; |
7cac2b65 | 183 | |
12a403af | 184 | sshpam_thread_status = -1; |
7cac2b65 | 185 | switch ((pid = fork())) { |
186 | case -1: | |
187 | error("fork(): %s", strerror(errno)); | |
188 | return (-1); | |
189 | case 0: | |
2ce0bfe4 | 190 | close(ctx->pam_psock); |
191 | ctx->pam_psock = -1; | |
7cac2b65 | 192 | thread_start(arg); |
193 | _exit(1); | |
194 | default: | |
195 | *thread = pid; | |
2ce0bfe4 | 196 | close(ctx->pam_csock); |
197 | ctx->pam_csock = -1; | |
540d72c3 | 198 | sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler); |
7cac2b65 | 199 | return (0); |
200 | } | |
201 | } | |
3c0ef626 | 202 | |
7cac2b65 | 203 | static int |
204 | pthread_cancel(sp_pthread_t thread) | |
3c0ef626 | 205 | { |
540d72c3 | 206 | signal(SIGCHLD, sshpam_oldsig); |
7cac2b65 | 207 | return (kill(thread, SIGTERM)); |
3c0ef626 | 208 | } |
209 | ||
30460aeb | 210 | /* ARGSUSED */ |
7cac2b65 | 211 | static int |
30460aeb | 212 | pthread_join(sp_pthread_t thread, void **value) |
3c0ef626 | 213 | { |
7cac2b65 | 214 | int status; |
215 | ||
540d72c3 | 216 | if (sshpam_thread_status != -1) |
217 | return (sshpam_thread_status); | |
218 | signal(SIGCHLD, sshpam_oldsig); | |
7cac2b65 | 219 | waitpid(thread, &status, 0); |
220 | return (status); | |
3c0ef626 | 221 | } |
7cac2b65 | 222 | #endif |
223 | ||
224 | ||
29d88157 | 225 | static pam_handle_t *sshpam_handle = NULL; |
226 | static int sshpam_err = 0; | |
227 | static int sshpam_authenticated = 0; | |
29d88157 | 228 | static int sshpam_session_open = 0; |
229 | static int sshpam_cred_established = 0; | |
540d72c3 | 230 | static int sshpam_account_status = -1; |
231 | static char **sshpam_env = NULL; | |
12a403af | 232 | static Authctxt *sshpam_authctxt = NULL; |
7e82606e | 233 | static const char *sshpam_password = NULL; |
dfddba3d | 234 | static char badpw[] = "\b\n\r\177INCORRECT"; |
540d72c3 | 235 | |
236 | /* Some PAM implementations don't implement this */ | |
237 | #ifndef HAVE_PAM_GETENVLIST | |
238 | static char ** | |
239 | pam_getenvlist(pam_handle_t *pamh) | |
240 | { | |
241 | /* | |
242 | * XXX - If necessary, we can still support envrionment passing | |
243 | * for platforms without pam_getenvlist by searching for known | |
244 | * env vars (e.g. KRB5CCNAME) from the PAM environment. | |
245 | */ | |
246 | return NULL; | |
247 | } | |
248 | #endif | |
7cac2b65 | 249 | |
7e82606e | 250 | /* |
251 | * Some platforms, notably Solaris, do not enforce password complexity | |
252 | * rules during pam_chauthtok() if the real uid of the calling process | |
253 | * is 0, on the assumption that it's being called by "passwd" run by root. | |
254 | * This wraps pam_chauthtok and sets/restore the real uid so PAM will do | |
255 | * the right thing. | |
256 | */ | |
257 | #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID | |
258 | static int | |
259 | sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags) | |
260 | { | |
261 | int result; | |
262 | ||
263 | if (sshpam_authctxt == NULL) | |
264 | fatal("PAM: sshpam_authctxt not initialized"); | |
265 | if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1) | |
266 | fatal("%s: setreuid failed: %s", __func__, strerror(errno)); | |
267 | result = pam_chauthtok(pamh, flags); | |
268 | if (setreuid(0, -1) == -1) | |
269 | fatal("%s: setreuid failed: %s", __func__, strerror(errno)); | |
270 | return result; | |
271 | } | |
272 | # define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b))) | |
273 | #endif | |
274 | ||
d037a8b0 | 275 | struct passwd * |
276 | sshpam_getpw(const char *user) | |
277 | { | |
278 | struct passwd *pw; | |
279 | ||
280 | if ((pw = getpwnam(user)) != NULL) | |
281 | return(pw); | |
282 | ||
283 | debug("PAM: faking passwd struct for user '%.100s'", user); | |
284 | if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) | |
285 | return NULL; | |
286 | pw->pw_name = xstrdup(user); /* XXX leak */ | |
287 | pw->pw_shell = "/bin/true"; | |
288 | pw->pw_gecos = "sshd fake PAM user"; | |
289 | return (pw); | |
290 | } | |
291 | ||
292 | void | |
293 | sshpam_check_userchanged(void) | |
294 | { | |
295 | int sshpam_err; | |
296 | struct passwd *pw; | |
297 | const char *user; | |
298 | ||
299 | debug("sshpam_check_userchanged"); | |
300 | sshpam_err = pam_get_item(sshpam_handle, PAM_USER, &user); | |
301 | if (sshpam_err != PAM_SUCCESS) | |
302 | fatal("PAM: could not get PAM_USER: %s", | |
303 | pam_strerror(sshpam_handle, sshpam_err)); | |
304 | if (strcmp(user, sshpam_authctxt->pw->pw_name) != 0) { | |
305 | debug("PAM: user mapped from '%.100s' to '%.100s'", | |
306 | sshpam_authctxt->pw->pw_name, user); | |
307 | if ((pw = getpwnam(user)) == NULL) | |
308 | fatal("PAM: could not get passwd entry for user " | |
309 | "'%.100s' provided by PAM_USER", user); | |
310 | pwfree(sshpam_authctxt->pw); | |
311 | sshpam_authctxt->pw = pw; | |
312 | sshpam_authctxt->valid = allowed_user(pw); | |
313 | debug("PAM: user '%.100s' now %svalid", user, | |
314 | sshpam_authctxt->valid ? "" : "in"); | |
315 | } | |
316 | } | |
317 | ||
540d72c3 | 318 | void |
7e82606e | 319 | sshpam_password_change_required(int reqd) |
540d72c3 | 320 | { |
321 | debug3("%s %d", __func__, reqd); | |
12a403af | 322 | if (sshpam_authctxt == NULL) |
323 | fatal("%s: PAM authctxt not initialized", __func__); | |
324 | sshpam_authctxt->force_pwchange = reqd; | |
540d72c3 | 325 | if (reqd) { |
326 | no_port_forwarding_flag |= 2; | |
327 | no_agent_forwarding_flag |= 2; | |
328 | no_x11_forwarding_flag |= 2; | |
329 | } else { | |
330 | no_port_forwarding_flag &= ~2; | |
331 | no_agent_forwarding_flag &= ~2; | |
332 | no_x11_forwarding_flag &= ~2; | |
333 | } | |
334 | } | |
7cac2b65 | 335 | |
540d72c3 | 336 | /* Import regular and PAM environment from subprocess */ |
337 | static void | |
338 | import_environments(Buffer *b) | |
339 | { | |
d037a8b0 | 340 | char *env, *user; |
540d72c3 | 341 | u_int i, num_env; |
342 | int err; | |
343 | ||
344 | debug3("PAM: %s entering", __func__); | |
345 | ||
8b32eddc | 346 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
540d72c3 | 347 | /* Import variables set by do_pam_account */ |
348 | sshpam_account_status = buffer_get_int(b); | |
7e82606e | 349 | sshpam_password_change_required(buffer_get_int(b)); |
d037a8b0 | 350 | if (options.permit_pam_user_change) { |
351 | user = buffer_get_string(b, NULL); | |
352 | debug("PAM: got username '%.100s' from thread", user); | |
353 | if ((err = pam_set_item(sshpam_handle, PAM_USER, user)) != PAM_SUCCESS) | |
354 | fatal("PAM: failed to set PAM_USER: %s", | |
355 | pam_strerror(sshpam_handle, err)); | |
356 | pwfree(sshpam_authctxt->pw); | |
357 | sshpam_authctxt->pw = pwcopy(sshpam_getpw(user)); | |
358 | } | |
540d72c3 | 359 | |
360 | /* Import environment from subprocess */ | |
361 | num_env = buffer_get_int(b); | |
30460aeb | 362 | if (num_env > 1024) |
363 | fatal("%s: received %u environment variables, expected <= 1024", | |
364 | __func__, num_env); | |
365 | sshpam_env = xcalloc(num_env + 1, sizeof(*sshpam_env)); | |
540d72c3 | 366 | debug3("PAM: num env strings %d", num_env); |
367 | for(i = 0; i < num_env; i++) | |
368 | sshpam_env[i] = buffer_get_string(b, NULL); | |
369 | ||
370 | sshpam_env[num_env] = NULL; | |
371 | ||
372 | /* Import PAM environment from subprocess */ | |
373 | num_env = buffer_get_int(b); | |
374 | debug("PAM: num PAM env strings %d", num_env); | |
375 | for(i = 0; i < num_env; i++) { | |
376 | env = buffer_get_string(b, NULL); | |
377 | ||
378 | #ifdef HAVE_PAM_PUTENV | |
379 | /* Errors are not fatal here */ | |
380 | if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { | |
381 | error("PAM: pam_putenv: %s", | |
382 | pam_strerror(sshpam_handle, sshpam_err)); | |
383 | } | |
384 | #endif | |
385 | } | |
12a403af | 386 | #endif |
540d72c3 | 387 | } |
3c0ef626 | 388 | |
389 | /* | |
7cac2b65 | 390 | * Conversation function for authentication thread. |
3c0ef626 | 391 | */ |
7cac2b65 | 392 | static int |
2ce0bfe4 | 393 | sshpam_thread_conv(int n, sshpam_const struct pam_message **msg, |
7cac2b65 | 394 | struct pam_response **resp, void *data) |
3c0ef626 | 395 | { |
7cac2b65 | 396 | Buffer buffer; |
397 | struct pam_ctxt *ctxt; | |
29d88157 | 398 | struct pam_response *reply; |
7cac2b65 | 399 | int i; |
400 | ||
540d72c3 | 401 | debug3("PAM: %s entering, %d messages", __func__, n); |
29d88157 | 402 | *resp = NULL; |
403 | ||
7e82606e | 404 | if (data == NULL) { |
405 | error("PAM: conversation function passed a null context"); | |
406 | return (PAM_CONV_ERR); | |
407 | } | |
7cac2b65 | 408 | ctxt = data; |
409 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
410 | return (PAM_CONV_ERR); | |
29d88157 | 411 | |
30460aeb | 412 | if ((reply = calloc(n, sizeof(*reply))) == NULL) |
29d88157 | 413 | return (PAM_CONV_ERR); |
29d88157 | 414 | |
7cac2b65 | 415 | buffer_init(&buffer); |
416 | for (i = 0; i < n; ++i) { | |
7cac2b65 | 417 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { |
418 | case PAM_PROMPT_ECHO_OFF: | |
540d72c3 | 419 | buffer_put_cstring(&buffer, |
29d88157 | 420 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 421 | if (ssh_msg_send(ctxt->pam_csock, |
422 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
423 | goto fail; | |
424 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
425 | goto fail; | |
7cac2b65 | 426 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
427 | goto fail; | |
29d88157 | 428 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 429 | break; |
430 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 431 | buffer_put_cstring(&buffer, |
29d88157 | 432 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 433 | if (ssh_msg_send(ctxt->pam_csock, |
434 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
435 | goto fail; | |
436 | if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) | |
437 | goto fail; | |
7cac2b65 | 438 | if (buffer_get_char(&buffer) != PAM_AUTHTOK) |
439 | goto fail; | |
29d88157 | 440 | reply[i].resp = buffer_get_string(&buffer, NULL); |
7cac2b65 | 441 | break; |
442 | case PAM_ERROR_MSG: | |
540d72c3 | 443 | buffer_put_cstring(&buffer, |
29d88157 | 444 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 445 | if (ssh_msg_send(ctxt->pam_csock, |
446 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
447 | goto fail; | |
7cac2b65 | 448 | break; |
449 | case PAM_TEXT_INFO: | |
540d72c3 | 450 | buffer_put_cstring(&buffer, |
29d88157 | 451 | PAM_MSG_MEMBER(msg, i, msg)); |
540d72c3 | 452 | if (ssh_msg_send(ctxt->pam_csock, |
453 | PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) | |
454 | goto fail; | |
7cac2b65 | 455 | break; |
456 | default: | |
457 | goto fail; | |
3c0ef626 | 458 | } |
7cac2b65 | 459 | buffer_clear(&buffer); |
3c0ef626 | 460 | } |
7cac2b65 | 461 | buffer_free(&buffer); |
29d88157 | 462 | *resp = reply; |
7cac2b65 | 463 | return (PAM_SUCCESS); |
29d88157 | 464 | |
7cac2b65 | 465 | fail: |
29d88157 | 466 | for(i = 0; i < n; i++) { |
467 | if (reply[i].resp != NULL) | |
468 | xfree(reply[i].resp); | |
469 | } | |
470 | xfree(reply); | |
7cac2b65 | 471 | buffer_free(&buffer); |
472 | return (PAM_CONV_ERR); | |
3c0ef626 | 473 | } |
474 | ||
7cac2b65 | 475 | /* |
476 | * Authentication thread. | |
477 | */ | |
478 | static void * | |
479 | sshpam_thread(void *ctxtp) | |
3c0ef626 | 480 | { |
7cac2b65 | 481 | struct pam_ctxt *ctxt = ctxtp; |
482 | Buffer buffer; | |
483 | struct pam_conv sshpam_conv; | |
7e82606e | 484 | int flags = (options.permit_empty_passwd == 0 ? |
485 | PAM_DISALLOW_NULL_AUTHTOK : 0); | |
8b32eddc | 486 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
540d72c3 | 487 | extern char **environ; |
488 | char **env_from_pam; | |
489 | u_int i; | |
7cac2b65 | 490 | const char *pam_user; |
2ce0bfe4 | 491 | const char **ptr_pam_user = &pam_user; |
30460aeb | 492 | char *tz = getenv("TZ"); |
7cac2b65 | 493 | |
2ce0bfe4 | 494 | pam_get_item(sshpam_handle, PAM_USER, |
495 | (sshpam_const void **)ptr_pam_user); | |
30460aeb | 496 | |
540d72c3 | 497 | environ[0] = NULL; |
30460aeb | 498 | if (tz != NULL) |
499 | if (setenv("TZ", tz, 1) == -1) | |
500 | error("PAM: could not set TZ environment: %s", | |
501 | strerror(errno)); | |
7e82606e | 502 | |
503 | if (sshpam_authctxt != NULL) { | |
504 | setproctitle("%s [pam]", | |
505 | sshpam_authctxt->valid ? pam_user : "unknown"); | |
506 | } | |
7cac2b65 | 507 | #endif |
3c0ef626 | 508 | |
7cac2b65 | 509 | sshpam_conv.conv = sshpam_thread_conv; |
510 | sshpam_conv.appdata_ptr = ctxt; | |
511 | ||
12a403af | 512 | if (sshpam_authctxt == NULL) |
513 | fatal("%s: PAM authctxt not initialized", __func__); | |
514 | ||
7cac2b65 | 515 | buffer_init(&buffer); |
516 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
517 | (const void *)&sshpam_conv); | |
518 | if (sshpam_err != PAM_SUCCESS) | |
519 | goto auth_fail; | |
7e82606e | 520 | sshpam_err = pam_authenticate(sshpam_handle, flags); |
7cac2b65 | 521 | if (sshpam_err != PAM_SUCCESS) |
522 | goto auth_fail; | |
540d72c3 | 523 | |
d037a8b0 | 524 | if (options.permit_pam_user_change) { |
525 | sshpam_check_userchanged(); | |
526 | } | |
540d72c3 | 527 | if (compat20) { |
30460aeb | 528 | if (!do_pam_account()) { |
529 | sshpam_err = PAM_ACCT_EXPIRED; | |
540d72c3 | 530 | goto auth_fail; |
30460aeb | 531 | } |
12a403af | 532 | if (sshpam_authctxt->force_pwchange) { |
540d72c3 | 533 | sshpam_err = pam_chauthtok(sshpam_handle, |
534 | PAM_CHANGE_EXPIRED_AUTHTOK); | |
535 | if (sshpam_err != PAM_SUCCESS) | |
536 | goto auth_fail; | |
7e82606e | 537 | sshpam_password_change_required(0); |
540d72c3 | 538 | } |
539 | } | |
540 | ||
7cac2b65 | 541 | buffer_put_cstring(&buffer, "OK"); |
540d72c3 | 542 | |
8b32eddc | 543 | #ifndef UNSUPPORTED_POSIX_THREADS_HACK |
540d72c3 | 544 | /* Export variables set by do_pam_account */ |
545 | buffer_put_int(&buffer, sshpam_account_status); | |
12a403af | 546 | buffer_put_int(&buffer, sshpam_authctxt->force_pwchange); |
d037a8b0 | 547 | if (options.permit_pam_user_change) { |
548 | buffer_put_cstring(&buffer, sshpam_authctxt->pw->pw_name); | |
549 | } | |
540d72c3 | 550 | |
551 | /* Export any environment strings set in child */ | |
552 | for(i = 0; environ[i] != NULL; i++) | |
553 | ; /* Count */ | |
554 | buffer_put_int(&buffer, i); | |
555 | for(i = 0; environ[i] != NULL; i++) | |
556 | buffer_put_cstring(&buffer, environ[i]); | |
557 | ||
558 | /* Export any environment strings set by PAM in child */ | |
559 | env_from_pam = pam_getenvlist(sshpam_handle); | |
560 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
561 | ; /* Count */ | |
562 | buffer_put_int(&buffer, i); | |
563 | for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) | |
564 | buffer_put_cstring(&buffer, env_from_pam[i]); | |
8b32eddc | 565 | #endif /* UNSUPPORTED_POSIX_THREADS_HACK */ |
540d72c3 | 566 | |
567 | /* XXX - can't do much about an error here */ | |
7cac2b65 | 568 | ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); |
569 | buffer_free(&buffer); | |
570 | pthread_exit(NULL); | |
571 | ||
572 | auth_fail: | |
573 | buffer_put_cstring(&buffer, | |
574 | pam_strerror(sshpam_handle, sshpam_err)); | |
540d72c3 | 575 | /* XXX - can't do much about an error here */ |
30460aeb | 576 | if (sshpam_err == PAM_ACCT_EXPIRED) |
577 | ssh_msg_send(ctxt->pam_csock, PAM_ACCT_EXPIRED, &buffer); | |
578 | else | |
579 | ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); | |
7cac2b65 | 580 | buffer_free(&buffer); |
581 | pthread_exit(NULL); | |
540d72c3 | 582 | |
7cac2b65 | 583 | return (NULL); /* Avoid warning for non-pthread case */ |
584 | } | |
3c0ef626 | 585 | |
540d72c3 | 586 | void |
587 | sshpam_thread_cleanup(void) | |
7cac2b65 | 588 | { |
540d72c3 | 589 | struct pam_ctxt *ctxt = cleanup_ctxt; |
590 | ||
591 | debug3("PAM: %s entering", __func__); | |
592 | if (ctxt != NULL && ctxt->pam_thread != 0) { | |
593 | pthread_cancel(ctxt->pam_thread); | |
594 | pthread_join(ctxt->pam_thread, NULL); | |
595 | close(ctxt->pam_psock); | |
596 | close(ctxt->pam_csock); | |
597 | memset(ctxt, 0, sizeof(*ctxt)); | |
598 | cleanup_ctxt = NULL; | |
599 | } | |
3c0ef626 | 600 | } |
601 | ||
7cac2b65 | 602 | static int |
2ce0bfe4 | 603 | sshpam_null_conv(int n, sshpam_const struct pam_message **msg, |
7cac2b65 | 604 | struct pam_response **resp, void *data) |
3c0ef626 | 605 | { |
540d72c3 | 606 | debug3("PAM: %s entering, %d messages", __func__, n); |
7cac2b65 | 607 | return (PAM_CONV_ERR); |
608 | } | |
3c0ef626 | 609 | |
7cac2b65 | 610 | static struct pam_conv null_conv = { sshpam_null_conv, NULL }; |
3c0ef626 | 611 | |
dfddba3d | 612 | static int |
2ce0bfe4 | 613 | sshpam_store_conv(int n, sshpam_const struct pam_message **msg, |
dfddba3d | 614 | struct pam_response **resp, void *data) |
615 | { | |
616 | struct pam_response *reply; | |
617 | int i; | |
618 | size_t len; | |
619 | ||
620 | debug3("PAM: %s called with %d messages", __func__, n); | |
621 | *resp = NULL; | |
622 | ||
623 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
624 | return (PAM_CONV_ERR); | |
625 | ||
30460aeb | 626 | if ((reply = calloc(n, sizeof(*reply))) == NULL) |
dfddba3d | 627 | return (PAM_CONV_ERR); |
dfddba3d | 628 | |
629 | for (i = 0; i < n; ++i) { | |
630 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
631 | case PAM_ERROR_MSG: | |
632 | case PAM_TEXT_INFO: | |
633 | len = strlen(PAM_MSG_MEMBER(msg, i, msg)); | |
634 | buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len); | |
635 | buffer_append(&loginmsg, "\n", 1 ); | |
636 | reply[i].resp_retcode = PAM_SUCCESS; | |
637 | break; | |
638 | default: | |
639 | goto fail; | |
640 | } | |
641 | } | |
642 | *resp = reply; | |
643 | return (PAM_SUCCESS); | |
644 | ||
645 | fail: | |
646 | for(i = 0; i < n; i++) { | |
647 | if (reply[i].resp != NULL) | |
648 | xfree(reply[i].resp); | |
649 | } | |
650 | xfree(reply); | |
651 | return (PAM_CONV_ERR); | |
652 | } | |
653 | ||
654 | static struct pam_conv store_conv = { sshpam_store_conv, NULL }; | |
655 | ||
540d72c3 | 656 | void |
657 | sshpam_cleanup(void) | |
7cac2b65 | 658 | { |
e74dc197 | 659 | if (sshpam_handle == NULL || (use_privsep && !mm_is_monitor())) |
29d88157 | 660 | return; |
e74dc197 | 661 | debug("PAM: cleanup"); |
7cac2b65 | 662 | pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); |
7cac2b65 | 663 | if (sshpam_session_open) { |
e74dc197 | 664 | debug("PAM: closing session"); |
7cac2b65 | 665 | pam_close_session(sshpam_handle, PAM_SILENT); |
666 | sshpam_session_open = 0; | |
667 | } | |
b5afdff5 | 668 | if (sshpam_cred_established) { |
669 | debug("PAM: deleting credentials"); | |
670 | pam_setcred(sshpam_handle, PAM_DELETE_CRED); | |
671 | sshpam_cred_established = 0; | |
672 | } | |
540d72c3 | 673 | sshpam_authenticated = 0; |
7cac2b65 | 674 | pam_end(sshpam_handle, sshpam_err); |
675 | sshpam_handle = NULL; | |
676 | } | |
3c0ef626 | 677 | |
7cac2b65 | 678 | static int |
12a403af | 679 | sshpam_init(Authctxt *authctxt) |
7cac2b65 | 680 | { |
7cac2b65 | 681 | extern char *__progname; |
12a403af | 682 | const char *pam_rhost, *pam_user, *user = authctxt->user; |
2ce0bfe4 | 683 | const char **ptr_pam_user = &pam_user; |
7cac2b65 | 684 | |
685 | if (sshpam_handle != NULL) { | |
686 | /* We already have a PAM context; check if the user matches */ | |
687 | sshpam_err = pam_get_item(sshpam_handle, | |
2ce0bfe4 | 688 | PAM_USER, (sshpam_const void **)ptr_pam_user); |
7cac2b65 | 689 | if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) |
690 | return (0); | |
7cac2b65 | 691 | pam_end(sshpam_handle, sshpam_err); |
692 | sshpam_handle = NULL; | |
693 | } | |
694 | debug("PAM: initializing for \"%s\"", user); | |
695 | sshpam_err = | |
dfddba3d | 696 | pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle); |
12a403af | 697 | sshpam_authctxt = authctxt; |
698 | ||
7cac2b65 | 699 | if (sshpam_err != PAM_SUCCESS) { |
700 | pam_end(sshpam_handle, sshpam_err); | |
701 | sshpam_handle = NULL; | |
702 | return (-1); | |
3c0ef626 | 703 | } |
7cac2b65 | 704 | pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); |
705 | debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); | |
706 | sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); | |
707 | if (sshpam_err != PAM_SUCCESS) { | |
708 | pam_end(sshpam_handle, sshpam_err); | |
709 | sshpam_handle = NULL; | |
710 | return (-1); | |
711 | } | |
712 | #ifdef PAM_TTY_KLUDGE | |
540d72c3 | 713 | /* |
714 | * Some silly PAM modules (e.g. pam_time) require a TTY to operate. | |
715 | * sshd doesn't set the tty until too late in the auth process and | |
7cac2b65 | 716 | * may not even set one (for tty-less connections) |
540d72c3 | 717 | */ |
7cac2b65 | 718 | debug("PAM: setting PAM_TTY to \"ssh\""); |
719 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); | |
720 | if (sshpam_err != PAM_SUCCESS) { | |
721 | pam_end(sshpam_handle, sshpam_err); | |
722 | sshpam_handle = NULL; | |
723 | return (-1); | |
724 | } | |
725 | #endif | |
7cac2b65 | 726 | return (0); |
3c0ef626 | 727 | } |
728 | ||
7cac2b65 | 729 | static void * |
730 | sshpam_init_ctx(Authctxt *authctxt) | |
3c0ef626 | 731 | { |
7cac2b65 | 732 | struct pam_ctxt *ctxt; |
733 | int socks[2]; | |
3c0ef626 | 734 | |
540d72c3 | 735 | debug3("PAM: %s entering", __func__); |
30460aeb | 736 | /* |
737 | * Refuse to start if we don't have PAM enabled or do_pam_account | |
738 | * has previously failed. | |
739 | */ | |
740 | if (!options.use_pam || sshpam_account_status == 0) | |
7cac2b65 | 741 | return NULL; |
3c0ef626 | 742 | |
7cac2b65 | 743 | /* Initialize PAM */ |
12a403af | 744 | if (sshpam_init(authctxt) == -1) { |
7cac2b65 | 745 | error("PAM: initialization failed"); |
746 | return (NULL); | |
3c0ef626 | 747 | } |
748 | ||
fa0f0f45 | 749 | ctxt = xcalloc(1, sizeof *ctxt); |
540d72c3 | 750 | |
7cac2b65 | 751 | /* Start the authentication thread */ |
752 | if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { | |
753 | error("PAM: failed create sockets: %s", strerror(errno)); | |
754 | xfree(ctxt); | |
755 | return (NULL); | |
756 | } | |
757 | ctxt->pam_psock = socks[0]; | |
758 | ctxt->pam_csock = socks[1]; | |
759 | if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { | |
760 | error("PAM: failed to start authentication thread: %s", | |
761 | strerror(errno)); | |
762 | close(socks[0]); | |
763 | close(socks[1]); | |
764 | xfree(ctxt); | |
765 | return (NULL); | |
766 | } | |
540d72c3 | 767 | cleanup_ctxt = ctxt; |
7cac2b65 | 768 | return (ctxt); |
769 | } | |
770 | ||
771 | static int | |
772 | sshpam_query(void *ctx, char **name, char **info, | |
773 | u_int *num, char ***prompts, u_int **echo_on) | |
774 | { | |
775 | Buffer buffer; | |
776 | struct pam_ctxt *ctxt = ctx; | |
777 | size_t plen; | |
778 | u_char type; | |
779 | char *msg; | |
dfddba3d | 780 | size_t len, mlen; |
7cac2b65 | 781 | |
540d72c3 | 782 | debug3("PAM: %s entering", __func__); |
7cac2b65 | 783 | buffer_init(&buffer); |
784 | *name = xstrdup(""); | |
785 | *info = xstrdup(""); | |
786 | *prompts = xmalloc(sizeof(char *)); | |
787 | **prompts = NULL; | |
788 | plen = 0; | |
789 | *echo_on = xmalloc(sizeof(u_int)); | |
790 | while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { | |
791 | type = buffer_get_char(&buffer); | |
792 | msg = buffer_get_string(&buffer, NULL); | |
dfddba3d | 793 | mlen = strlen(msg); |
7cac2b65 | 794 | switch (type) { |
795 | case PAM_PROMPT_ECHO_ON: | |
796 | case PAM_PROMPT_ECHO_OFF: | |
797 | *num = 1; | |
dfddba3d | 798 | len = plen + mlen + 1; |
30460aeb | 799 | **prompts = xrealloc(**prompts, 1, len); |
dfddba3d | 800 | strlcpy(**prompts + plen, msg, len - plen); |
801 | plen += mlen; | |
7cac2b65 | 802 | **echo_on = (type == PAM_PROMPT_ECHO_ON); |
803 | xfree(msg); | |
804 | return (0); | |
805 | case PAM_ERROR_MSG: | |
806 | case PAM_TEXT_INFO: | |
807 | /* accumulate messages */ | |
dfddba3d | 808 | len = plen + mlen + 2; |
30460aeb | 809 | **prompts = xrealloc(**prompts, 1, len); |
dfddba3d | 810 | strlcpy(**prompts + plen, msg, len - plen); |
811 | plen += mlen; | |
812 | strlcat(**prompts + plen, "\n", len - plen); | |
813 | plen++; | |
7cac2b65 | 814 | xfree(msg); |
3c0ef626 | 815 | break; |
30460aeb | 816 | case PAM_ACCT_EXPIRED: |
817 | sshpam_account_status = 0; | |
818 | /* FALLTHROUGH */ | |
7cac2b65 | 819 | case PAM_AUTH_ERR: |
30460aeb | 820 | debug3("PAM: %s", pam_strerror(sshpam_handle, type)); |
08822d99 | 821 | if (**prompts != NULL && strlen(**prompts) != 0) { |
822 | *info = **prompts; | |
823 | **prompts = NULL; | |
824 | *num = 0; | |
825 | **echo_on = 0; | |
826 | ctxt->pam_done = -1; | |
30460aeb | 827 | xfree(msg); |
08822d99 | 828 | return 0; |
829 | } | |
830 | /* FALLTHROUGH */ | |
831 | case PAM_SUCCESS: | |
7cac2b65 | 832 | if (**prompts != NULL) { |
833 | /* drain any accumulated messages */ | |
540d72c3 | 834 | debug("PAM: %s", **prompts); |
835 | buffer_append(&loginmsg, **prompts, | |
836 | strlen(**prompts)); | |
7cac2b65 | 837 | xfree(**prompts); |
838 | **prompts = NULL; | |
839 | } | |
840 | if (type == PAM_SUCCESS) { | |
dfddba3d | 841 | if (!sshpam_authctxt->valid || |
842 | (sshpam_authctxt->pw->pw_uid == 0 && | |
843 | options.permit_root_login != PERMIT_YES)) | |
844 | fatal("Internal error: PAM auth " | |
845 | "succeeded when it should have " | |
846 | "failed"); | |
540d72c3 | 847 | import_environments(&buffer); |
7cac2b65 | 848 | *num = 0; |
849 | **echo_on = 0; | |
850 | ctxt->pam_done = 1; | |
851 | xfree(msg); | |
852 | return (0); | |
853 | } | |
12a403af | 854 | error("PAM: %s for %s%.100s from %.100s", msg, |
855 | sshpam_authctxt->valid ? "" : "illegal user ", | |
856 | sshpam_authctxt->user, | |
857 | get_remote_name_or_ip(utmp_len, options.use_dns)); | |
540d72c3 | 858 | /* FALLTHROUGH */ |
3c0ef626 | 859 | default: |
7cac2b65 | 860 | *num = 0; |
861 | **echo_on = 0; | |
862 | xfree(msg); | |
863 | ctxt->pam_done = -1; | |
864 | return (-1); | |
865 | } | |
3c0ef626 | 866 | } |
7cac2b65 | 867 | return (-1); |
3c0ef626 | 868 | } |
869 | ||
7cac2b65 | 870 | /* XXX - see also comment in auth-chall.c:verify_response */ |
871 | static int | |
872 | sshpam_respond(void *ctx, u_int num, char **resp) | |
3c0ef626 | 873 | { |
7cac2b65 | 874 | Buffer buffer; |
875 | struct pam_ctxt *ctxt = ctx; | |
876 | ||
08822d99 | 877 | debug2("PAM: %s entering, %u responses", __func__, num); |
7cac2b65 | 878 | switch (ctxt->pam_done) { |
879 | case 1: | |
880 | sshpam_authenticated = 1; | |
881 | return (0); | |
882 | case 0: | |
883 | break; | |
884 | default: | |
885 | return (-1); | |
3c0ef626 | 886 | } |
7cac2b65 | 887 | if (num != 1) { |
888 | error("PAM: expected one response, got %u", num); | |
889 | return (-1); | |
890 | } | |
891 | buffer_init(&buffer); | |
dfddba3d | 892 | if (sshpam_authctxt->valid && |
893 | (sshpam_authctxt->pw->pw_uid != 0 || | |
2ce0bfe4 | 894 | options.permit_root_login == PERMIT_YES)) |
dfddba3d | 895 | buffer_put_cstring(&buffer, *resp); |
896 | else | |
897 | buffer_put_cstring(&buffer, badpw); | |
540d72c3 | 898 | if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { |
899 | buffer_free(&buffer); | |
900 | return (-1); | |
901 | } | |
7cac2b65 | 902 | buffer_free(&buffer); |
903 | return (1); | |
3c0ef626 | 904 | } |
905 | ||
7cac2b65 | 906 | static void |
907 | sshpam_free_ctx(void *ctxtp) | |
3c0ef626 | 908 | { |
7cac2b65 | 909 | struct pam_ctxt *ctxt = ctxtp; |
350391c5 | 910 | |
540d72c3 | 911 | debug3("PAM: %s entering", __func__); |
912 | sshpam_thread_cleanup(); | |
7cac2b65 | 913 | xfree(ctxt); |
914 | /* | |
915 | * We don't call sshpam_cleanup() here because we may need the PAM | |
916 | * handle at a later stage, e.g. when setting up a session. It's | |
917 | * still on the cleanup list, so pam_end() *will* be called before | |
918 | * the server process terminates. | |
919 | */ | |
3c0ef626 | 920 | } |
921 | ||
7cac2b65 | 922 | KbdintDevice sshpam_device = { |
923 | "pam", | |
924 | sshpam_init_ctx, | |
925 | sshpam_query, | |
926 | sshpam_respond, | |
927 | sshpam_free_ctx | |
928 | }; | |
929 | ||
930 | KbdintDevice mm_sshpam_device = { | |
931 | "pam", | |
932 | mm_sshpam_init_ctx, | |
933 | mm_sshpam_query, | |
934 | mm_sshpam_respond, | |
935 | mm_sshpam_free_ctx | |
936 | }; | |
3c0ef626 | 937 | |
938 | /* | |
7cac2b65 | 939 | * This replaces auth-pam.c |
3c0ef626 | 940 | */ |
7cac2b65 | 941 | void |
12a403af | 942 | start_pam(Authctxt *authctxt) |
3c0ef626 | 943 | { |
7cac2b65 | 944 | if (!options.use_pam) |
945 | fatal("PAM: initialisation requested when UsePAM=no"); | |
946 | ||
12a403af | 947 | if (sshpam_init(authctxt) == -1) |
7cac2b65 | 948 | fatal("PAM: initialisation failed"); |
3c0ef626 | 949 | } |
950 | ||
7cac2b65 | 951 | void |
952 | finish_pam(void) | |
3c0ef626 | 953 | { |
540d72c3 | 954 | sshpam_cleanup(); |
3c0ef626 | 955 | } |
956 | ||
7cac2b65 | 957 | u_int |
958 | do_pam_account(void) | |
3c0ef626 | 959 | { |
dfddba3d | 960 | debug("%s: called", __func__); |
540d72c3 | 961 | if (sshpam_account_status != -1) |
962 | return (sshpam_account_status); | |
963 | ||
7cac2b65 | 964 | sshpam_err = pam_acct_mgmt(sshpam_handle, 0); |
dfddba3d | 965 | debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err, |
966 | pam_strerror(sshpam_handle, sshpam_err)); | |
2ce0bfe4 | 967 | |
d037a8b0 | 968 | if (options.permit_pam_user_change) { |
969 | sshpam_check_userchanged(); | |
970 | if (getpwnam(sshpam_authctxt->pw->pw_name) == NULL) | |
971 | fatal("PAM: completed authentication but PAM account invalid"); | |
972 | } | |
973 | ||
540d72c3 | 974 | if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) { |
975 | sshpam_account_status = 0; | |
976 | return (sshpam_account_status); | |
7cac2b65 | 977 | } |
3c0ef626 | 978 | |
540d72c3 | 979 | if (sshpam_err == PAM_NEW_AUTHTOK_REQD) |
7e82606e | 980 | sshpam_password_change_required(1); |
3c0ef626 | 981 | |
540d72c3 | 982 | sshpam_account_status = 1; |
983 | return (sshpam_account_status); | |
7cac2b65 | 984 | } |
3c0ef626 | 985 | |
7cac2b65 | 986 | void |
987 | do_pam_set_tty(const char *tty) | |
988 | { | |
989 | if (tty != NULL) { | |
990 | debug("PAM: setting PAM_TTY to \"%s\"", tty); | |
991 | sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); | |
992 | if (sshpam_err != PAM_SUCCESS) | |
993 | fatal("PAM: failed to set PAM_TTY: %s", | |
994 | pam_strerror(sshpam_handle, sshpam_err)); | |
995 | } | |
996 | } | |
3c0ef626 | 997 | |
7cac2b65 | 998 | void |
999 | do_pam_setcred(int init) | |
1000 | { | |
1001 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
dfddba3d | 1002 | (const void *)&store_conv); |
7cac2b65 | 1003 | if (sshpam_err != PAM_SUCCESS) |
1004 | fatal("PAM: failed to set PAM_CONV: %s", | |
1005 | pam_strerror(sshpam_handle, sshpam_err)); | |
1006 | if (init) { | |
1007 | debug("PAM: establishing credentials"); | |
1008 | sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); | |
1009 | } else { | |
1010 | debug("PAM: reinitializing credentials"); | |
1011 | sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); | |
1012 | } | |
1013 | if (sshpam_err == PAM_SUCCESS) { | |
1014 | sshpam_cred_established = 1; | |
1015 | return; | |
1016 | } | |
1017 | if (sshpam_authenticated) | |
1018 | fatal("PAM: pam_setcred(): %s", | |
1019 | pam_strerror(sshpam_handle, sshpam_err)); | |
1020 | else | |
1021 | debug("PAM: pam_setcred(): %s", | |
1022 | pam_strerror(sshpam_handle, sshpam_err)); | |
3c0ef626 | 1023 | } |
1024 | ||
7cac2b65 | 1025 | static int |
2ce0bfe4 | 1026 | sshpam_tty_conv(int n, sshpam_const struct pam_message **msg, |
7cac2b65 | 1027 | struct pam_response **resp, void *data) |
23987cb8 | 1028 | { |
7cac2b65 | 1029 | char input[PAM_MAX_MSG_SIZE]; |
29d88157 | 1030 | struct pam_response *reply; |
23987cb8 | 1031 | int i; |
1032 | ||
540d72c3 | 1033 | debug3("PAM: %s called with %d messages", __func__, n); |
1034 | ||
29d88157 | 1035 | *resp = NULL; |
1036 | ||
540d72c3 | 1037 | if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) |
7cac2b65 | 1038 | return (PAM_CONV_ERR); |
29d88157 | 1039 | |
30460aeb | 1040 | if ((reply = calloc(n, sizeof(*reply))) == NULL) |
29d88157 | 1041 | return (PAM_CONV_ERR); |
29d88157 | 1042 | |
7cac2b65 | 1043 | for (i = 0; i < n; ++i) { |
1044 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
1045 | case PAM_PROMPT_ECHO_OFF: | |
29d88157 | 1046 | reply[i].resp = |
540d72c3 | 1047 | read_passphrase(PAM_MSG_MEMBER(msg, i, msg), |
7cac2b65 | 1048 | RP_ALLOW_STDIN); |
29d88157 | 1049 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 1050 | break; |
1051 | case PAM_PROMPT_ECHO_ON: | |
540d72c3 | 1052 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
fa0f0f45 | 1053 | if (fgets(input, sizeof input, stdin) == NULL) |
1054 | input[0] = '\0'; | |
7e82606e | 1055 | if ((reply[i].resp = strdup(input)) == NULL) |
1056 | goto fail; | |
29d88157 | 1057 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 1058 | break; |
1059 | case PAM_ERROR_MSG: | |
1060 | case PAM_TEXT_INFO: | |
540d72c3 | 1061 | fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); |
29d88157 | 1062 | reply[i].resp_retcode = PAM_SUCCESS; |
7cac2b65 | 1063 | break; |
1064 | default: | |
1065 | goto fail; | |
1066 | } | |
23987cb8 | 1067 | } |
29d88157 | 1068 | *resp = reply; |
7cac2b65 | 1069 | return (PAM_SUCCESS); |
29d88157 | 1070 | |
7cac2b65 | 1071 | fail: |
29d88157 | 1072 | for(i = 0; i < n; i++) { |
1073 | if (reply[i].resp != NULL) | |
1074 | xfree(reply[i].resp); | |
1075 | } | |
1076 | xfree(reply); | |
7cac2b65 | 1077 | return (PAM_CONV_ERR); |
23987cb8 | 1078 | } |
1079 | ||
7e82606e | 1080 | static struct pam_conv tty_conv = { sshpam_tty_conv, NULL }; |
540d72c3 | 1081 | |
7cac2b65 | 1082 | /* |
1083 | * XXX this should be done in the authentication phase, but ssh1 doesn't | |
1084 | * support that | |
1085 | */ | |
1086 | void | |
1087 | do_pam_chauthtok(void) | |
1088 | { | |
7cac2b65 | 1089 | if (use_privsep) |
1090 | fatal("Password expired (unable to change with privsep)"); | |
1091 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
540d72c3 | 1092 | (const void *)&tty_conv); |
7cac2b65 | 1093 | if (sshpam_err != PAM_SUCCESS) |
1094 | fatal("PAM: failed to set PAM_CONV: %s", | |
1095 | pam_strerror(sshpam_handle, sshpam_err)); | |
1096 | debug("PAM: changing password"); | |
1097 | sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); | |
1098 | if (sshpam_err != PAM_SUCCESS) | |
1099 | fatal("PAM: pam_chauthtok(): %s", | |
1100 | pam_strerror(sshpam_handle, sshpam_err)); | |
1101 | } | |
1102 | ||
540d72c3 | 1103 | void |
1104 | do_pam_session(void) | |
1105 | { | |
1106 | debug3("PAM: opening session"); | |
1107 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
1108 | (const void *)&store_conv); | |
1109 | if (sshpam_err != PAM_SUCCESS) | |
1110 | fatal("PAM: failed to set PAM_CONV: %s", | |
1111 | pam_strerror(sshpam_handle, sshpam_err)); | |
1112 | sshpam_err = pam_open_session(sshpam_handle, 0); | |
dfddba3d | 1113 | if (sshpam_err == PAM_SUCCESS) |
1114 | sshpam_session_open = 1; | |
1115 | else { | |
1116 | sshpam_session_open = 0; | |
1117 | disable_forwarding(); | |
1118 | error("PAM: pam_open_session(): %s", | |
540d72c3 | 1119 | pam_strerror(sshpam_handle, sshpam_err)); |
dfddba3d | 1120 | } |
1121 | ||
1122 | } | |
1123 | ||
1124 | int | |
1125 | is_pam_session_open(void) | |
1126 | { | |
1127 | return sshpam_session_open; | |
540d72c3 | 1128 | } |
1129 | ||
1130 | /* | |
7cac2b65 | 1131 | * Set a PAM environment string. We need to do this so that the session |
5598e598 | 1132 | * modules can handle things like Kerberos/GSI credentials that appear |
1133 | * during the ssh authentication process. | |
1134 | */ | |
7cac2b65 | 1135 | int |
540d72c3 | 1136 | do_pam_putenv(char *name, char *value) |
7cac2b65 | 1137 | { |
1138 | int ret = 1; | |
540d72c3 | 1139 | #ifdef HAVE_PAM_PUTENV |
5598e598 | 1140 | char *compound; |
7cac2b65 | 1141 | size_t len; |
905081a4 | 1142 | |
7cac2b65 | 1143 | len = strlen(name) + strlen(value) + 2; |
1144 | compound = xmalloc(len); | |
1145 | ||
1146 | snprintf(compound, len, "%s=%s", name, value); | |
1147 | ret = pam_putenv(sshpam_handle, compound); | |
1148 | xfree(compound); | |
905081a4 | 1149 | #endif |
7cac2b65 | 1150 | |
1151 | return (ret); | |
5598e598 | 1152 | } |
1153 | ||
540d72c3 | 1154 | char ** |
1155 | fetch_pam_child_environment(void) | |
3c0ef626 | 1156 | { |
540d72c3 | 1157 | return sshpam_env; |
3c0ef626 | 1158 | } |
1159 | ||
7cac2b65 | 1160 | char ** |
1161 | fetch_pam_environment(void) | |
3c0ef626 | 1162 | { |
7cac2b65 | 1163 | return (pam_getenvlist(sshpam_handle)); |
7cac2b65 | 1164 | } |
3c0ef626 | 1165 | |
7cac2b65 | 1166 | void |
1167 | free_pam_environment(char **env) | |
1168 | { | |
1169 | char **envp; | |
3c0ef626 | 1170 | |
7cac2b65 | 1171 | if (env == NULL) |
1172 | return; | |
3c0ef626 | 1173 | |
7cac2b65 | 1174 | for (envp = env; *envp; envp++) |
1175 | xfree(*envp); | |
1176 | xfree(env); | |
3c0ef626 | 1177 | } |
1178 | ||
7e82606e | 1179 | /* |
1180 | * "Blind" conversation function for password authentication. Assumes that | |
1181 | * echo-off prompts are for the password and stores messages for later | |
1182 | * display. | |
1183 | */ | |
1184 | static int | |
2ce0bfe4 | 1185 | sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg, |
7e82606e | 1186 | struct pam_response **resp, void *data) |
1187 | { | |
1188 | struct pam_response *reply; | |
1189 | int i; | |
1190 | size_t len; | |
1191 | ||
1192 | debug3("PAM: %s called with %d messages", __func__, n); | |
1193 | ||
1194 | *resp = NULL; | |
1195 | ||
1196 | if (n <= 0 || n > PAM_MAX_NUM_MSG) | |
1197 | return (PAM_CONV_ERR); | |
1198 | ||
fa0f0f45 | 1199 | if ((reply = calloc(n, sizeof(*reply))) == NULL) |
7e82606e | 1200 | return (PAM_CONV_ERR); |
7e82606e | 1201 | |
1202 | for (i = 0; i < n; ++i) { | |
1203 | switch (PAM_MSG_MEMBER(msg, i, msg_style)) { | |
1204 | case PAM_PROMPT_ECHO_OFF: | |
1205 | if (sshpam_password == NULL) | |
1206 | goto fail; | |
1207 | if ((reply[i].resp = strdup(sshpam_password)) == NULL) | |
1208 | goto fail; | |
1209 | reply[i].resp_retcode = PAM_SUCCESS; | |
1210 | break; | |
1211 | case PAM_ERROR_MSG: | |
1212 | case PAM_TEXT_INFO: | |
1213 | len = strlen(PAM_MSG_MEMBER(msg, i, msg)); | |
1214 | if (len > 0) { | |
1215 | buffer_append(&loginmsg, | |
1216 | PAM_MSG_MEMBER(msg, i, msg), len); | |
1217 | buffer_append(&loginmsg, "\n", 1); | |
1218 | } | |
1219 | if ((reply[i].resp = strdup("")) == NULL) | |
1220 | goto fail; | |
1221 | reply[i].resp_retcode = PAM_SUCCESS; | |
1222 | break; | |
1223 | default: | |
1224 | goto fail; | |
1225 | } | |
1226 | } | |
1227 | *resp = reply; | |
1228 | return (PAM_SUCCESS); | |
1229 | ||
2ce0bfe4 | 1230 | fail: |
7e82606e | 1231 | for(i = 0; i < n; i++) { |
1232 | if (reply[i].resp != NULL) | |
1233 | xfree(reply[i].resp); | |
1234 | } | |
1235 | xfree(reply); | |
1236 | return (PAM_CONV_ERR); | |
1237 | } | |
1238 | ||
1239 | static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL }; | |
1240 | ||
1241 | /* | |
1242 | * Attempt password authentication via PAM | |
1243 | */ | |
1244 | int | |
1245 | sshpam_auth_passwd(Authctxt *authctxt, const char *password) | |
1246 | { | |
1247 | int flags = (options.permit_empty_passwd == 0 ? | |
1248 | PAM_DISALLOW_NULL_AUTHTOK : 0); | |
7e82606e | 1249 | |
1250 | if (!options.use_pam || sshpam_handle == NULL) | |
1251 | fatal("PAM: %s called when PAM disabled or failed to " | |
1252 | "initialise.", __func__); | |
1253 | ||
1254 | sshpam_password = password; | |
1255 | sshpam_authctxt = authctxt; | |
1256 | ||
1257 | /* | |
1258 | * If the user logging in is invalid, or is root but is not permitted | |
1259 | * by PermitRootLogin, use an invalid password to prevent leaking | |
1260 | * information via timing (eg if the PAM config has a delay on fail). | |
1261 | */ | |
1262 | if (!authctxt->valid || (authctxt->pw->pw_uid == 0 && | |
2ce0bfe4 | 1263 | options.permit_root_login != PERMIT_YES)) |
7e82606e | 1264 | sshpam_password = badpw; |
1265 | ||
1266 | sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, | |
1267 | (const void *)&passwd_conv); | |
1268 | if (sshpam_err != PAM_SUCCESS) | |
1269 | fatal("PAM: %s: failed to set PAM_CONV: %s", __func__, | |
1270 | pam_strerror(sshpam_handle, sshpam_err)); | |
1271 | ||
1272 | sshpam_err = pam_authenticate(sshpam_handle, flags); | |
d037a8b0 | 1273 | if (options.permit_pam_user_change) { |
1274 | sshpam_check_userchanged(); | |
1275 | } | |
7e82606e | 1276 | sshpam_password = NULL; |
1277 | if (sshpam_err == PAM_SUCCESS && authctxt->valid) { | |
1278 | debug("PAM: password authentication accepted for %.100s", | |
1279 | authctxt->user); | |
2ce0bfe4 | 1280 | return 1; |
7e82606e | 1281 | } else { |
1282 | debug("PAM: password authentication failed for %.100s: %s", | |
1283 | authctxt->valid ? authctxt->user : "an illegal user", | |
1284 | pam_strerror(sshpam_handle, sshpam_err)); | |
1285 | return 0; | |
1286 | } | |
1287 | } | |
3c0ef626 | 1288 | #endif /* USE_PAM */ |