2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2001,2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2017 Dag-Erling Smørgrav
6 * Copyright (c) 2018 Thomas Munro
9 * This software was developed for the FreeBSD Project by ThinkSec AS and
10 * NAI Labs, the Security Research Division of Network Associates, Inc.
11 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
12 * DARPA CHATS research program.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. The name of the author may not be used to endorse or promote
23 * products derived from this software without specific prior written
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
42 #include <sys/types.h>
44 #include <sys/procdesc.h>
54 #include <security/pam_appl.h>
55 #include <security/pam_modules.h>
56 #include <security/openpam.h>
58 #define PAM_ITEM_ENV(n) { (n), #n }
63 PAM_ITEM_ENV(PAM_SERVICE),
64 PAM_ITEM_ENV(PAM_USER),
65 PAM_ITEM_ENV(PAM_TTY),
66 PAM_ITEM_ENV(PAM_RHOST),
67 PAM_ITEM_ENV(PAM_RUSER),
69 #define NUM_PAM_ITEM_ENV (sizeof(pam_item_env) / sizeof(pam_item_env[0]))
71 #define PAM_ERR_ENV_X(str, num) str "=" #num
72 #define PAM_ERR_ENV(pam_err) PAM_ERR_ENV_X(#pam_err, pam_err)
73 static const char *pam_err_env[] = {
74 PAM_ERR_ENV(PAM_SUCCESS),
75 PAM_ERR_ENV(PAM_OPEN_ERR),
76 PAM_ERR_ENV(PAM_SYMBOL_ERR),
77 PAM_ERR_ENV(PAM_SERVICE_ERR),
78 PAM_ERR_ENV(PAM_SYSTEM_ERR),
79 PAM_ERR_ENV(PAM_BUF_ERR),
80 PAM_ERR_ENV(PAM_CONV_ERR),
81 PAM_ERR_ENV(PAM_PERM_DENIED),
82 PAM_ERR_ENV(PAM_MAXTRIES),
83 PAM_ERR_ENV(PAM_AUTH_ERR),
84 PAM_ERR_ENV(PAM_NEW_AUTHTOK_REQD),
85 PAM_ERR_ENV(PAM_CRED_INSUFFICIENT),
86 PAM_ERR_ENV(PAM_AUTHINFO_UNAVAIL),
87 PAM_ERR_ENV(PAM_USER_UNKNOWN),
88 PAM_ERR_ENV(PAM_CRED_UNAVAIL),
89 PAM_ERR_ENV(PAM_CRED_EXPIRED),
90 PAM_ERR_ENV(PAM_CRED_ERR),
91 PAM_ERR_ENV(PAM_ACCT_EXPIRED),
92 PAM_ERR_ENV(PAM_AUTHTOK_EXPIRED),
93 PAM_ERR_ENV(PAM_SESSION_ERR),
94 PAM_ERR_ENV(PAM_AUTHTOK_ERR),
95 PAM_ERR_ENV(PAM_AUTHTOK_RECOVERY_ERR),
96 PAM_ERR_ENV(PAM_AUTHTOK_LOCK_BUSY),
97 PAM_ERR_ENV(PAM_AUTHTOK_DISABLE_AGING),
98 PAM_ERR_ENV(PAM_NO_MODULE_DATA),
99 PAM_ERR_ENV(PAM_IGNORE),
100 PAM_ERR_ENV(PAM_ABORT),
101 PAM_ERR_ENV(PAM_TRY_AGAIN),
102 PAM_ERR_ENV(PAM_MODULE_UNKNOWN),
103 PAM_ERR_ENV(PAM_DOMAIN_UNKNOWN),
104 PAM_ERR_ENV(PAM_NUM_ERR),
106 #define NUM_PAM_ERR_ENV (sizeof(pam_err_env) / sizeof(pam_err_env[0]))
109 int return_prog_exit_status;
116 parse_options(const char *func, int *argc, const char **argv[],
117 struct pe_opts *options)
123 * return_prog_exit_status:
124 * use the program exit status as the return code of pam_exec
126 * stop options parsing; what follows is the command to execute
128 memset(options, 0, sizeof(*options));
130 for (i = 0; i < *argc; ++i) {
131 if (strcmp((*argv)[i], "debug") == 0 ||
132 strcmp((*argv)[i], "no_warn") == 0) {
134 } else if (strcmp((*argv)[i], "capture_stdout") == 0) {
135 options->capture_stdout = 1;
136 } else if (strcmp((*argv)[i], "capture_stderr") == 0) {
137 options->capture_stderr = 1;
138 } else if (strcmp((*argv)[i], "return_prog_exit_status") == 0) {
139 options->return_prog_exit_status = 1;
140 } else if (strcmp((*argv)[i], "expose_authtok") == 0) {
141 options->expose_authtok = 1;
143 if (strcmp((*argv)[i], "--") == 0) {
149 openpam_log(PAM_LOG_DEBUG, "%s: option \"%s\" enabled",
160 _pam_exec(pam_handle_t *pamh,
161 const char *func, int flags __unused, int argc, const char *argv[],
162 struct pe_opts *options)
164 char buf[PAM_MAX_MSG_SIZE];
165 struct pollfd pfd[4];
167 char **envlist, *envstr, *resp, **tmp;
169 int envlen, extralen, i;
170 int pam_err, serrno, status;
171 int chin[2], chout[2], cherr[2], pd;
172 nfds_t nfds, nreadfds;
180 chin[0] = chin[1] = chout[0] = chout[1] = cherr[0] = cherr[1] = -1;
183 #define OUT(ret) do { pam_err = (ret); goto out; } while (0)
185 /* Check there's a program name left after parsing options. */
187 openpam_log(PAM_LOG_ERROR, "%s: No program specified: aborting",
189 OUT(PAM_SERVICE_ERR);
193 * Set up the child's environment list. It consists of the PAM
194 * environment, a few hand-picked PAM items, the name of the
195 * service function, and if return_prog_exit_status is set, the
196 * numerical values of all PAM error codes.
199 /* compute the final size of the environment. */
200 envlist = pam_getenvlist(pamh);
201 for (envlen = 0; envlist[envlen] != NULL; ++envlen)
203 extralen = NUM_PAM_ITEM_ENV + 1;
204 if (options->return_prog_exit_status)
205 extralen += NUM_PAM_ERR_ENV;
206 tmp = reallocarray(envlist, envlen + extralen + 1, sizeof(*envlist));
207 openpam_log(PAM_LOG_DEBUG, "envlen = %d extralen = %d tmp = %p",
208 envlen, extralen, tmp);
214 /* copy selected PAM items to the environment */
215 for (i = 0; i < NUM_PAM_ITEM_ENV; ++i) {
216 pam_err = pam_get_item(pamh, pam_item_env[i].item, &item);
217 if (pam_err != PAM_SUCCESS || item == NULL)
219 if (asprintf(&envstr, "%s=%s", pam_item_env[i].name, item) < 0)
221 envlist[envlen++] = envstr;
222 envlist[envlen] = NULL;
223 openpam_log(PAM_LOG_DEBUG, "setenv %s", envstr);
226 /* add the name of the service function to the environment */
227 if (asprintf(&envstr, "PAM_SM_FUNC=%s", func) < 0)
229 envlist[envlen++] = envstr;
230 envlist[envlen] = NULL;
232 /* add the PAM error codes to the environment. */
233 if (options->return_prog_exit_status) {
234 for (i = 0; i < (int)NUM_PAM_ERR_ENV; ++i) {
235 if ((envstr = strdup(pam_err_env[i])) == NULL)
237 envlist[envlen++] = envstr;
238 envlist[envlen] = NULL;
242 openpam_log(PAM_LOG_DEBUG, "envlen = %d extralen = %d envlist = %p",
243 envlen, extralen, envlist);
245 /* set up pipe and get authtok if requested */
246 if (options->expose_authtok) {
247 if (pipe(chin) != 0) {
248 openpam_log(PAM_LOG_ERROR, "%s: pipe(): %m", func);
251 if (fcntl(chin[1], F_SETFL, O_NONBLOCK)) {
252 openpam_log(PAM_LOG_ERROR, "%s: fcntl(): %m", func);
255 rc = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL);
256 if (rc == PAM_SUCCESS) {
257 /* We include the trailing NUL-terminator. */
258 authtok_size = strlen(authtok) + 1;
260 openpam_log(PAM_LOG_ERROR, "%s: pam_get_authtok(): %s", func,
261 pam_strerror(pamh, rc));
265 /* set up pipes if capture was requested */
266 if (options->capture_stdout) {
267 if (pipe(chout) != 0) {
268 openpam_log(PAM_LOG_ERROR, "%s: pipe(): %m", func);
271 if (fcntl(chout[0], F_SETFL, O_NONBLOCK) != 0) {
272 openpam_log(PAM_LOG_ERROR, "%s: fcntl(): %m", func);
276 if ((chout[1] = open("/dev/null", O_RDWR)) < 0) {
277 openpam_log(PAM_LOG_ERROR, "%s: /dev/null: %m", func);
281 if (options->capture_stderr) {
282 if (pipe(cherr) != 0) {
283 openpam_log(PAM_LOG_ERROR, "%s: pipe(): %m", func);
286 if (fcntl(cherr[0], F_SETFL, O_NONBLOCK) != 0) {
287 openpam_log(PAM_LOG_ERROR, "%s: fcntl(): %m", func);
291 if ((cherr[1] = open("/dev/null", O_RDWR)) < 0) {
292 openpam_log(PAM_LOG_ERROR, "%s: /dev/null: %m", func);
297 if ((pid = pdfork(&pd, 0)) == 0) {
299 if ((chin[1] >= 0 && close(chin[1]) != 0) ||
300 (chout[0] >= 0 && close(chout[0]) != 0) ||
301 (cherr[0] >= 0 && close(cherr[0]) != 0)) {
302 openpam_log(PAM_LOG_ERROR, "%s: close(): %m", func);
303 } else if (chin[0] >= 0 &&
304 dup2(chin[0], STDIN_FILENO) != STDIN_FILENO) {
305 openpam_log(PAM_LOG_ERROR, "%s: dup2(): %m", func);
306 } else if (dup2(chout[1], STDOUT_FILENO) != STDOUT_FILENO ||
307 dup2(cherr[1], STDERR_FILENO) != STDERR_FILENO) {
308 openpam_log(PAM_LOG_ERROR, "%s: dup2(): %m", func);
310 execve(argv[0], (char * const *)argv,
311 (char * const *)envlist);
312 openpam_log(PAM_LOG_ERROR, "%s: execve(%s): %m",
319 openpam_log(PAM_LOG_ERROR, "%s: pdfork(): %m", func);
322 /* use poll() to watch the process and stdin / stdout / stderr */
329 memset(pfd, 0, sizeof pfd);
331 pfd[0].events = POLLHUP;
334 if (options->capture_stdout) {
335 pfd[nfds].fd = chout[0];
336 pfd[nfds].events = POLLIN|POLLERR|POLLHUP;
340 if (options->capture_stderr) {
341 pfd[nfds].fd = cherr[0];
342 pfd[nfds].events = POLLIN|POLLERR|POLLHUP;
346 if (options->expose_authtok) {
347 pfd[nfds].fd = chin[1];
348 pfd[nfds].events = POLLOUT|POLLERR|POLLHUP;
352 /* loop until the process exits */
354 if (poll(pfd, nfds, INFTIM) < 0) {
355 openpam_log(PAM_LOG_ERROR, "%s: poll(): %m", func);
358 /* are the stderr / stdout pipes ready for reading? */
359 for (i = 1; i < 1 + nreadfds; ++i) {
360 if ((pfd[i].revents & POLLIN) == 0)
362 if ((rlen = read(pfd[i].fd, buf, sizeof(buf) - 1)) < 0) {
363 openpam_log(PAM_LOG_ERROR, "%s: read(): %m",
366 } else if (rlen == 0) {
370 (void)pam_prompt(pamh, pfd[i].fd == chout[0] ?
371 PAM_TEXT_INFO : PAM_ERROR_MSG, &resp, "%s", buf);
373 /* is the stdin pipe ready for writing? */
374 if (options->expose_authtok && authtok_size > 0 &&
375 (pfd[nfds - 1].revents & POLLOUT) != 0) {
376 if ((wlen = write(chin[1], authtok, authtok_size)) < 0) {
379 openpam_log(PAM_LOG_ERROR, "%s: write(): %m",
384 authtok_size -= wlen;
385 if (authtok_size == 0) {
386 /* finished writing; close and forget the pipe */
393 } while (pfd[0].revents == 0);
395 /* the child process has exited */
396 while (waitpid(pid, &status, 0) == -1) {
399 openpam_log(PAM_LOG_ERROR, "%s: waitpid(): %m", func);
403 /* check exit code */
404 if (WIFSIGNALED(status)) {
405 openpam_log(PAM_LOG_ERROR, "%s: %s caught signal %d%s",
406 func, argv[0], WTERMSIG(status),
407 WCOREDUMP(status) ? " (core dumped)" : "");
408 OUT(PAM_SERVICE_ERR);
410 if (!WIFEXITED(status)) {
411 openpam_log(PAM_LOG_ERROR, "%s: unknown status 0x%x",
413 OUT(PAM_SERVICE_ERR);
416 if (options->return_prog_exit_status) {
417 openpam_log(PAM_LOG_DEBUG,
418 "%s: Use program exit status as return value: %d",
419 func, WEXITSTATUS(status));
420 OUT(WEXITSTATUS(status));
422 OUT(WEXITSTATUS(status) == 0 ? PAM_SUCCESS : PAM_PERM_DENIED);
442 openpam_free_envlist(envlist);
448 pam_sm_authenticate(pam_handle_t *pamh, int flags,
449 int argc, const char *argv[])
452 struct pe_opts options;
454 ret = parse_options(__func__, &argc, &argv, &options);
456 return (PAM_SERVICE_ERR);
458 ret = _pam_exec(pamh, __func__, flags, argc, argv, &options);
461 * We must check that the program returned a valid code for this
467 case PAM_AUTHINFO_UNAVAIL:
471 case PAM_CRED_INSUFFICIENT:
474 case PAM_PERM_DENIED:
475 case PAM_SERVICE_ERR:
477 case PAM_USER_UNKNOWN:
480 openpam_log(PAM_LOG_ERROR, "%s returned invalid code %d",
482 ret = PAM_SERVICE_ERR;
489 pam_sm_setcred(pam_handle_t *pamh, int flags,
490 int argc, const char *argv[])
493 struct pe_opts options;
495 ret = parse_options(__func__, &argc, &argv, &options);
497 return (PAM_SERVICE_ERR);
499 ret = _pam_exec(pamh, __func__, flags, argc, argv, &options);
502 * We must check that the program returned a valid code for this
511 case PAM_CRED_EXPIRED:
512 case PAM_CRED_UNAVAIL:
514 case PAM_PERM_DENIED:
515 case PAM_SERVICE_ERR:
517 case PAM_USER_UNKNOWN:
520 openpam_log(PAM_LOG_ERROR, "%s returned invalid code %d",
522 ret = PAM_SERVICE_ERR;
529 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
530 int argc, const char *argv[])
533 struct pe_opts options;
535 ret = parse_options(__func__, &argc, &argv, &options);
537 return (PAM_SERVICE_ERR);
539 ret = _pam_exec(pamh, __func__, flags, argc, argv, &options);
542 * We must check that the program returned a valid code for this
548 case PAM_ACCT_EXPIRED:
553 case PAM_NEW_AUTHTOK_REQD:
554 case PAM_PERM_DENIED:
555 case PAM_SERVICE_ERR:
557 case PAM_USER_UNKNOWN:
560 openpam_log(PAM_LOG_ERROR, "%s returned invalid code %d",
562 ret = PAM_SERVICE_ERR;
569 pam_sm_open_session(pam_handle_t *pamh, int flags,
570 int argc, const char *argv[])
573 struct pe_opts options;
575 ret = parse_options(__func__, &argc, &argv, &options);
577 return (PAM_SERVICE_ERR);
579 ret = _pam_exec(pamh, __func__, flags, argc, argv, &options);
582 * We must check that the program returned a valid code for this
591 case PAM_PERM_DENIED:
592 case PAM_SERVICE_ERR:
593 case PAM_SESSION_ERR:
597 openpam_log(PAM_LOG_ERROR, "%s returned invalid code %d",
599 ret = PAM_SERVICE_ERR;
606 pam_sm_close_session(pam_handle_t *pamh, int flags,
607 int argc, const char *argv[])
610 struct pe_opts options;
612 ret = parse_options(__func__, &argc, &argv, &options);
614 return (PAM_SERVICE_ERR);
616 ret = _pam_exec(pamh, __func__, flags, argc, argv, &options);
619 * We must check that the program returned a valid code for this
628 case PAM_PERM_DENIED:
629 case PAM_SERVICE_ERR:
630 case PAM_SESSION_ERR:
634 openpam_log(PAM_LOG_ERROR, "%s returned invalid code %d",
636 ret = PAM_SERVICE_ERR;
643 pam_sm_chauthtok(pam_handle_t *pamh, int flags,
644 int argc, const char *argv[])
647 struct pe_opts options;
649 ret = parse_options(__func__, &argc, &argv, &options);
651 return (PAM_SERVICE_ERR);
653 ret = _pam_exec(pamh, __func__, flags, argc, argv, &options);
656 * We must check that the program returned a valid code for this
662 case PAM_AUTHTOK_DISABLE_AGING:
663 case PAM_AUTHTOK_ERR:
664 case PAM_AUTHTOK_LOCK_BUSY:
665 case PAM_AUTHTOK_RECOVERY_ERR:
669 case PAM_PERM_DENIED:
670 case PAM_SERVICE_ERR:
675 openpam_log(PAM_LOG_ERROR, "%s returned invalid code %d",
677 ret = PAM_SERVICE_ERR;
683 PAM_MODULE_ENTRY("pam_exec");