4 * Copyright information at end of file.
19 #include <security/_pam_macros.h>
20 #include <security/pam_modules.h>
25 extern char *crypt(const char *key, const char *salt);
26 extern char *bigcrypt(const char *key, const char *salt);
28 /* syslogging function for errors and other information */
30 void _log_err(int err, pam_handle_t *pamh, const char *format,...)
36 pam_get_item(pamh, PAM_SERVICE, (const void **) &service);
38 strncpy(logname, service, sizeof(logname));
39 logname[sizeof(logname) - 1 - strlen("(pam_unix)")] = '\0';
40 strncat(logname, "(pam_unix)", strlen("(pam_unix)"));
42 strncpy(logname, "pam_unix", sizeof(logname) - 1);
45 va_start(args, format);
46 openlog(logname, LOG_CONS | LOG_PID, LOG_AUTH);
47 vsyslog(err, format, args);
52 /* this is a front-end for module-application conversations */
54 static int converse(pam_handle_t * pamh, int ctrl, int nargs
55 ,struct pam_message **message
56 ,struct pam_response **response)
59 struct pam_conv *conv;
61 D(("begin to converse"));
63 retval = pam_get_item(pamh, PAM_CONV, (const void **) &conv);
64 if (retval == PAM_SUCCESS) {
66 retval = conv->conv(nargs, (const struct pam_message **) message
67 ,response, conv->appdata_ptr);
69 D(("returned from application's conversation function"));
71 if (retval != PAM_SUCCESS && on(UNIX_DEBUG, ctrl)) {
72 _log_err(LOG_DEBUG, pamh, "conversation failure [%s]"
73 ,pam_strerror(pamh, retval));
75 } else if (retval != PAM_CONV_AGAIN) {
76 _log_err(LOG_ERR, pamh
77 ,"couldn't obtain coversation function [%s]"
78 ,pam_strerror(pamh, retval));
80 D(("ready to return from module conversation"));
82 return retval; /* propagate error status */
85 int _make_remark(pam_handle_t * pamh, unsigned int ctrl
86 ,int type, const char *text)
88 int retval = PAM_SUCCESS;
90 if (off(UNIX__QUIET, ctrl)) {
91 struct pam_message *pmsg[1], msg[1];
92 struct pam_response *resp;
96 msg[0].msg_style = type;
99 retval = converse(pamh, ctrl, 1, pmsg, &resp);
102 _pam_drop_reply(resp, 1);
109 * Beacause getlogin() is braindead and sometimes it just
110 * doesn't work, we reimplement it here.
112 char *PAM_getlogin(void)
114 struct utmp *ut, line;
115 char *curr_tty, *retval;
116 static char curr_user[sizeof(ut->ut_user) + 4];
120 curr_tty = ttyname(0);
121 if (curr_tty != NULL) {
122 D(("PAM_getlogin ttyname: %s", curr_tty));
125 strncpy(line.ut_line, curr_tty, sizeof line.ut_line);
126 if ((ut = getutline(&line)) != NULL) {
127 strncpy(curr_user, ut->ut_user, sizeof(ut->ut_user));
132 D(("PAM_getlogin retval: %s", retval));
138 * set the control flags for the UNIX module.
141 int _set_ctrl(pam_handle_t *pamh, int flags, int *remember, int argc,
148 ctrl = UNIX_DEFAULTS; /* the default selection of options */
150 /* set some flags manually */
152 if (getuid() == 0 && !(flags & PAM_CHANGE_EXPIRED_AUTHTOK)) {
154 set(UNIX__IAMROOT, ctrl);
156 if (flags & PAM_UPDATE_AUTHTOK) {
157 D(("UPDATE_AUTHTOK"));
158 set(UNIX__UPDATE, ctrl);
160 if (flags & PAM_PRELIM_CHECK) {
162 set(UNIX__PRELIM, ctrl);
164 if (flags & PAM_DISALLOW_NULL_AUTHTOK) {
165 D(("DISALLOW_NULL_AUTHTOK"));
166 set(UNIX__NONULL, ctrl);
168 if (flags & PAM_SILENT) {
170 set(UNIX__QUIET, ctrl);
172 /* now parse the arguments to this module */
177 D(("pam_unix arg: %s", *argv));
179 for (j = 0; j < UNIX_CTRLS_; ++j) {
180 if (unix_args[j].token
181 && !strncmp(*argv, unix_args[j].token, strlen(unix_args[j].token))) {
186 if (j >= UNIX_CTRLS_) {
187 _log_err(LOG_ERR, pamh,
188 "unrecognized option [%s]", *argv);
190 ctrl &= unix_args[j].mask; /* for turning things off */
191 ctrl |= unix_args[j].flag; /* for turning things on */
193 if (remember != NULL) {
194 if (j == UNIX_REMEMBER_PASSWD) {
195 *remember = strtol(*argv + 9, NULL, 10);
196 if ((*remember == LONG_MIN) || (*remember == LONG_MAX))
204 ++argv; /* step to next argument */
207 /* auditing is a more sensitive version of debug */
209 if (on(UNIX_AUDIT, ctrl)) {
210 set(UNIX_DEBUG, ctrl);
212 /* return the set of flags */
218 static void _cleanup(pam_handle_t * pamh, void *x, int error_status)
223 /* ************************************************************** *
224 * Useful non-trivial functions *
225 * ************************************************************** */
228 * the following is used to keep track of the number of times a user fails
229 * to authenticate themself.
232 #define FAIL_PREFIX "-UN*X-FAIL-"
233 #define UNIX_MAX_RETRIES 3
235 struct _pam_failed_auth {
236 char *user; /* user that's failed to be authenticated */
237 char *name; /* attempt from user with name */
238 int uid; /* uid of calling user */
239 int euid; /* euid of calling process */
240 int count; /* number of failures so far */
243 #ifndef PAM_DATA_REPLACE
244 #error "Need to get an updated libpam 0.52 or better"
247 static void _cleanup_failures(pam_handle_t * pamh, void *fl, int err)
250 const char *service = NULL;
251 const char *ruser = NULL;
252 const char *rhost = NULL;
253 const char *tty = NULL;
254 struct _pam_failed_auth *failure;
258 quiet = err & PAM_DATA_SILENT; /* should we log something? */
259 err &= PAM_DATA_REPLACE; /* are we just replacing data? */
260 failure = (struct _pam_failed_auth *) fl;
262 if (failure != NULL) {
264 if (!quiet && !err) { /* under advisement from Sun,may go away */
266 /* log the number of authentication failures */
267 if (failure->count > 1) {
268 (void) pam_get_item(pamh, PAM_SERVICE,
269 (const void **)&service);
270 (void) pam_get_item(pamh, PAM_RUSER,
271 (const void **)&ruser);
272 (void) pam_get_item(pamh, PAM_RHOST,
273 (const void **)&rhost);
274 (void) pam_get_item(pamh, PAM_TTY,
275 (const void **)&tty);
276 _log_err(LOG_NOTICE, pamh,
277 "%d more authentication failure%s; "
278 "logname=%s uid=%d euid=%d "
279 "tty=%s ruser=%s rhost=%s "
281 failure->count - 1, failure->count == 2 ? "" : "s",
282 failure->name, failure->uid, failure->euid,
283 tty ? tty : "", ruser ? ruser : "",
285 (failure->user && failure->user[0] != '\0')
286 ? " user=" : "", failure->user
289 if (failure->count > UNIX_MAX_RETRIES) {
290 _log_err(LOG_ALERT, pamh
291 ,"service(%s) ignoring max retries; %d > %d"
292 ,service == NULL ? "**unknown**" : service
298 _pam_delete(failure->user); /* tidy up */
299 _pam_delete(failure->name); /* tidy up */
305 * _unix_blankpasswd() is a quick check for a blank password
307 * returns TRUE if user does not have a password
308 * - to avoid prompting for one in such cases (CG)
311 int _unix_blankpasswd(unsigned int ctrl, const char *name)
313 struct passwd *pwd = NULL;
314 struct spwd *spwdent = NULL;
320 struct passwd pwd_buf;
328 * This function does not have to be too smart if something goes
329 * wrong, return FALSE and let this case to be treated somewhere
333 if (on(UNIX__NONULL, ctrl))
334 return 0; /* will fail but don't let on yet */
336 /* UNIX passwords area */
338 /* Get password file entry... */
341 buf = malloc(bufsize);
343 if ((retval = getpwnam_r(name, pwd, buf, bufsize, &pwd))) {
346 while (retval == ERANGE) {
348 buf = realloc(buf, bufsize);
349 if ((retval getpwnam_r(name, pwd, buf, bufsize, &pwd))) {
354 pwd = getpwnam(name);
358 if (strcmp( pwd->pw_passwd, "*NP*" ) == 0)
360 uid_t save_euid, save_uid;
362 save_euid = geteuid();
364 if (save_uid == pwd->pw_uid)
365 setreuid( save_euid, save_uid );
368 if (setreuid( -1, pwd->pw_uid ) == -1) {
371 if(setreuid( -1, pwd->pw_uid ) == -1)
372 /* Will fail elsewhere. */
381 spwdent = getspnam( name );
382 if (save_uid == pwd->pw_uid)
383 setreuid( save_uid, save_euid );
385 if (setreuid( -1, 0 ) == -1)
386 setreuid( save_uid, -1 );
387 setreuid( -1, save_euid );
389 } else if (strcmp(pwd->pw_passwd, "x") == 0) {
391 * ...and shadow password file entry for this user,
392 * if shadowing is enabled
394 spwdent = getspnam(name);
397 salt = x_strdup(spwdent->sp_pwdp);
399 salt = x_strdup(pwd->pw_passwd);
401 /* Does this user have a password? */
405 if (strlen(salt) == 0)
425 * verify the password of a user
428 #include <sys/types.h>
429 #include <sys/wait.h>
431 static int _unix_run_helper_binary(pam_handle_t *pamh, const char *passwd,
432 unsigned int ctrl, const char *user)
434 int retval, child, fds[2];
437 /* create a pipe for the password */
438 if (pipe(fds) != 0) {
439 D(("could not make pipe"));
446 static char *envp[] = { NULL };
447 char *args[] = { NULL, NULL, NULL };
449 /* XXX - should really tidy up PAM here too */
451 /* reopen stdin as pipe */
453 dup2(fds[0], STDIN_FILENO);
455 /* exec binary helper */
456 args[0] = x_strdup(CHKPWD_HELPER);
457 args[1] = x_strdup(user);
459 execve(CHKPWD_HELPER, args, envp);
461 /* should not get here: exit with error */
462 D(("helper binary is not available"));
463 exit(PAM_AUTHINFO_UNAVAIL);
464 } else if (child > 0) {
466 /* if the stored password is NULL */
467 if (off(UNIX__NONULL, ctrl)) { /* this means we've succeeded */
468 write(fds[1], "nullok\0\0", 8);
470 write(fds[1], "nonull\0\0", 8);
472 if (passwd != NULL) { /* send the password to the child */
473 write(fds[1], passwd, strlen(passwd)+1);
476 write(fds[1], "", 1); /* blank password */
478 close(fds[0]); /* close here to avoid possible SIGPIPE above */
480 (void) waitpid(child, &retval, 0); /* wait for helper to complete */
481 retval = (retval == 0) ? PAM_SUCCESS:PAM_AUTH_ERR;
484 retval = PAM_AUTH_ERR;
487 D(("returning %d", retval));
491 int _unix_verify_password(pam_handle_t * pamh, const char *name
492 ,const char *p, unsigned int ctrl)
494 struct passwd *pwd = NULL;
495 struct spwd *spwdent = NULL;
503 #ifdef HAVE_PAM_FAIL_DELAY
504 if (off(UNIX_NODELAY, ctrl)) {
505 D(("setting delay"));
506 (void) pam_fail_delay(pamh, 2000000); /* 2 sec delay for on failure */
510 /* locate the entry for this user */
512 D(("locating user's record"));
514 /* UNIX passwords area */
515 pwd = getpwnam(name); /* Get password file entry... */
518 if (strcmp( pwd->pw_passwd, "*NP*" ) == 0)
520 uid_t save_euid, save_uid;
522 save_euid = geteuid();
524 if (save_uid == pwd->pw_uid)
525 setreuid( save_euid, save_uid );
528 if (setreuid( -1, pwd->pw_uid ) == -1) {
531 if(setreuid( -1, pwd->pw_uid ) == -1)
532 return PAM_CRED_INSUFFICIENT;
536 spwdent = getspnam( name );
537 if (save_uid == pwd->pw_uid)
538 setreuid( save_uid, save_euid );
540 if (setreuid( -1, 0 ) == -1)
541 setreuid( save_uid, -1 );
542 setreuid( -1, save_euid );
544 } else if (strcmp(pwd->pw_passwd, "x") == 0) {
546 * ...and shadow password file entry for this user,
547 * if shadowing is enabled
549 spwdent = getspnam(name);
552 salt = x_strdup(spwdent->sp_pwdp);
554 salt = x_strdup(pwd->pw_passwd);
557 data_name = (char *) malloc(sizeof(FAIL_PREFIX) + strlen(name));
558 if (data_name == NULL) {
559 _log_err(LOG_CRIT, pamh, "no memory for data-name");
561 strcpy(data_name, FAIL_PREFIX);
562 strcpy(data_name + sizeof(FAIL_PREFIX) - 1, name);
565 retval = PAM_SUCCESS;
566 if (pwd == NULL || salt == NULL || !strcmp(salt, "x")) {
568 /* we are not root perhaps this is the reason? Run helper */
569 D(("running helper binary"));
570 retval = _unix_run_helper_binary(pamh, p, ctrl, name);
571 if (pwd == NULL && !on(UNIX_AUDIT,ctrl)
572 && retval != PAM_SUCCESS)
577 D(("user's record unavailable"));
578 if (on(UNIX_AUDIT, ctrl)) {
579 /* this might be a typo and the user has given a password
580 instead of a username. Careful with this. */
581 _log_err(LOG_ALERT, pamh,
582 "check pass; user (%s) unknown", name);
585 _log_err(LOG_ALERT, pamh,
586 "check pass; user unknown");
589 retval = PAM_AUTHINFO_UNAVAIL;
593 /* the stored password is NULL */
594 if (off(UNIX__NONULL, ctrl)) { /* this means we've succeeded */
595 D(("user has empty password - access granted"));
596 retval = PAM_SUCCESS;
598 D(("user has empty password - access denied"));
599 retval = PAM_AUTH_ERR;
602 retval = PAM_AUTH_ERR;
604 if (!strncmp(salt, "$1$", 3)) {
605 pp = Goodcrypt_md5(p, salt);
606 if (strcmp(pp, salt) != 0) {
608 pp = Brokencrypt_md5(p, salt);
611 pp = bigcrypt(p, salt);
613 p = NULL; /* no longer needed here */
615 /* the moment of truth -- do we agree with the password? */
616 D(("comparing state of pp[%s] and salt[%s]", pp, salt));
618 if (strcmp(pp, salt) == 0) {
619 retval = PAM_SUCCESS;
621 retval = PAM_AUTH_ERR;
626 if (retval == PAM_SUCCESS) {
627 if (data_name) /* reset failures */
628 pam_set_data(pamh, data_name, NULL, _cleanup_failures);
630 if (data_name != NULL) {
631 struct _pam_failed_auth *new = NULL;
632 const struct _pam_failed_auth *old = NULL;
634 /* get a failure recorder */
636 new = (struct _pam_failed_auth *)
637 malloc(sizeof(struct _pam_failed_auth));
641 new->user = x_strdup(name ? name : "");
643 new->euid = geteuid();
644 new->name = x_strdup(PAM_getlogin()? PAM_getlogin() : "");
646 /* any previous failures for this user ? */
647 pam_get_data(pamh, data_name, (const void **) &old);
650 new->count = old->count + 1;
651 if (new->count >= UNIX_MAX_RETRIES) {
652 retval = PAM_MAXTRIES;
655 const char *service=NULL;
656 const char *ruser=NULL;
657 const char *rhost=NULL;
658 const char *tty=NULL;
660 (void) pam_get_item(pamh, PAM_SERVICE,
661 (const void **)&service);
662 (void) pam_get_item(pamh, PAM_RUSER,
663 (const void **)&ruser);
664 (void) pam_get_item(pamh, PAM_RHOST,
665 (const void **)&rhost);
666 (void) pam_get_item(pamh, PAM_TTY,
667 (const void **)&tty);
669 _log_err(LOG_NOTICE, pamh,
670 "authentication failure; "
671 "logname=%s uid=%d euid=%d "
672 "tty=%s ruser=%s rhost=%s "
674 new->name, new->uid, new->euid,
678 (new->user && new->user[0] != '\0')
685 pam_set_data(pamh, data_name, new, _cleanup_failures);
688 _log_err(LOG_CRIT, pamh,
689 "no memory for failure recorder");
695 _pam_delete(data_name);
701 D(("done [%d].", retval));
707 * obtain a password from the user
710 int _unix_read_password(pam_handle_t * pamh
715 ,const char *data_name
725 * make sure nothing inappropriate gets returned
728 *pass = token = NULL;
731 * which authentication token are we getting?
734 authtok_flag = on(UNIX__OLD_PASSWD, ctrl) ? PAM_OLDAUTHTOK : PAM_AUTHTOK;
737 * should we obtain the password from a PAM item ?
740 if (on(UNIX_TRY_FIRST_PASS, ctrl) || on(UNIX_USE_FIRST_PASS, ctrl)) {
741 retval = pam_get_item(pamh, authtok_flag, (const void **) pass);
742 if (retval != PAM_SUCCESS) {
744 _log_err(LOG_ALERT, pamh
745 ,"pam_get_item returned error to unix-read-password"
748 } else if (*pass != NULL) { /* we have a password! */
750 } else if (on(UNIX_USE_FIRST_PASS, ctrl)) {
751 return PAM_AUTHTOK_RECOVER_ERR; /* didn't work */
752 } else if (on(UNIX_USE_AUTHTOK, ctrl)
753 && off(UNIX__OLD_PASSWD, ctrl)) {
754 return PAM_AUTHTOK_RECOVER_ERR;
758 * getting here implies we will have to get the password from the
763 struct pam_message msg[3], *pmsg[3];
764 struct pam_response *resp;
767 /* prepare to converse */
769 if (comment != NULL && off(UNIX__QUIET, ctrl)) {
771 msg[0].msg_style = PAM_TEXT_INFO;
772 msg[0].msg = comment;
779 msg[i].msg_style = PAM_PROMPT_ECHO_OFF;
780 msg[i++].msg = prompt1;
783 if (prompt2 != NULL) {
785 msg[i].msg_style = PAM_PROMPT_ECHO_OFF;
786 msg[i++].msg = prompt2;
789 /* so call the conversation expecting i responses */
791 retval = converse(pamh, ctrl, i, pmsg, &resp);
795 /* interpret the response */
797 if (retval == PAM_SUCCESS) { /* a good conversation */
799 token = x_strdup(resp[i - replies].resp);
803 /* verify that password entered correctly */
804 if (!resp[i - 1].resp
805 || strcmp(token, resp[i - 1].resp)) {
806 _pam_delete(token); /* mistyped */
807 retval = PAM_AUTHTOK_RECOVER_ERR;
808 _make_remark(pamh, ctrl
809 ,PAM_ERROR_MSG, MISTYPED_PASS);
813 _log_err(LOG_NOTICE, pamh
814 ,"could not recover authentication token");
819 * tidy up the conversation (resp_retcode) is ignored
820 * -- what is it for anyway? AGM
823 _pam_drop_reply(resp, i);
826 retval = (retval == PAM_SUCCESS)
827 ? PAM_AUTHTOK_RECOVER_ERR : retval;
831 if (retval != PAM_SUCCESS) {
832 if (on(UNIX_DEBUG, ctrl))
833 _log_err(LOG_DEBUG, pamh,
834 "unable to obtain a password");
837 /* 'token' is the entered password */
839 if (off(UNIX_NOT_SET_PASS, ctrl)) {
841 /* we store this password as an item */
843 retval = pam_set_item(pamh, authtok_flag, token);
844 _pam_delete(token); /* clean it up */
845 if (retval != PAM_SUCCESS
846 || (retval = pam_get_item(pamh, authtok_flag
847 ,(const void **) pass))
851 _log_err(LOG_CRIT, pamh, "error manipulating password");
857 * then store it as data specific to this module. pam_end()
858 * will arrange to clean it up.
861 retval = pam_set_data(pamh, data_name, (void *) token, _cleanup);
862 if (retval != PAM_SUCCESS) {
863 _log_err(LOG_CRIT, pamh
864 ,"error manipulating password data [%s]"
865 ,pam_strerror(pamh, retval));
870 token = NULL; /* break link to password */
876 /* ****************************************************************** *
877 * Copyright (c) Jan Rêkorajski 1999.
878 * Copyright (c) Andrew G. Morgan 1996-8.
879 * Copyright (c) Alex O. Yuriev, 1996.
880 * Copyright (c) Cristian Gafton 1996.
882 * Redistribution and use in source and binary forms, with or without
883 * modification, are permitted provided that the following conditions
885 * 1. Redistributions of source code must retain the above copyright
886 * notice, and the entire permission notice in its entirety,
887 * including the disclaimer of warranties.
888 * 2. Redistributions in binary form must reproduce the above copyright
889 * notice, this list of conditions and the following disclaimer in the
890 * documentation and/or other materials provided with the distribution.
891 * 3. The name of the author may not be used to endorse or promote
892 * products derived from this software without specific prior
893 * written permission.
895 * ALTERNATIVELY, this product may be distributed under the terms of
896 * the GNU Public License, in which case the provisions of the GPL are
897 * required INSTEAD OF the above restrictions. (This clause is
898 * necessary due to a potential bad interaction between the GPL and
899 * the restrictions contained in a BSD-style copyright.)
901 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
902 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
903 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
904 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
905 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
906 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
907 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
908 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
909 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
910 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
911 * OF THE POSSIBILITY OF SUCH DAMAGE.