2 * auth.c - PPP authentication and phase control.
4 * Copyright (c) 1993 The Australian National University.
7 * Redistribution and use in source and binary forms are permitted
8 * provided that the above copyright notice and this paragraph are
9 * duplicated in all such forms and that any documentation,
10 * advertising materials, and other materials related to such
11 * distribution and use acknowledge that the software was developed
12 * by the Australian National University. The name of the University
13 * may not be used to endorse or promote products derived from this
14 * software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 * Copyright (c) 1989 Carnegie Mellon University.
20 * All rights reserved.
22 * Redistribution and use in source and binary forms are permitted
23 * provided that the above copyright notice and this paragraph are
24 * duplicated in all such forms and that any documentation,
25 * advertising materials, and other materials related to such
26 * distribution and use acknowledge that the software was developed
27 * by Carnegie Mellon University. The name of the
28 * University may not be used to endorse or promote products derived
29 * from this software without specific prior written permission.
30 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
32 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
35 #define RCSID "$Id: auth.c,v 1.68 2001/03/08 05:11:10 paulus Exp $"
44 #include <sys/types.h>
46 #include <sys/socket.h>
49 #if defined(_PATH_LASTLOG) && defined(_linux_)
54 #include <netinet/in.h>
55 #include <arpa/inet.h>
58 #include <security/pam_appl.h>
64 #define PW_PPP PW_LOGIN
77 #include "pathnames.h"
79 static const char rcsid[] = RCSID;
81 /* Bits in scan_authfile return value */
82 #define NONWILD_SERVER 1
83 #define NONWILD_CLIENT 2
85 #define ISWILD(word) (word[0] == '*' && word[1] == 0)
87 /* The name by which the peer authenticated itself to us. */
88 char peer_authname[MAXNAMELEN];
90 /* Records which authentication operations haven't completed yet. */
91 static int auth_pending[NUM_PPP];
93 /* Set if we have successfully called plogin() */
96 /* List of addresses which the peer may use. */
97 static struct permitted_ip *addresses[NUM_PPP];
99 /* Wordlist giving addresses which the peer may use
100 without authenticating itself. */
101 static struct wordlist *noauth_addrs;
103 /* Extra options to apply, from the secrets file entry for the peer. */
104 static struct wordlist *extra_options;
106 /* Number of network protocols which we have opened. */
107 static int num_np_open;
109 /* Number of network protocols which have come up. */
110 static int num_np_up;
112 /* Set if we got the contents of passwd[] from the pap-secrets file. */
113 static int passwd_from_file;
115 /* Set if we require authentication only because we have a default route. */
116 static bool default_auth;
118 /* Hook to enable a plugin to control the idle time limit */
119 int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;
121 /* Hook for a plugin to say whether we can possibly authenticate any peer */
122 int (*pap_check_hook) __P((void)) = NULL;
124 /* Hook for a plugin to check the PAP user and password */
125 int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
126 struct wordlist **paddrs,
127 struct wordlist **popts)) = NULL;
129 /* Hook for a plugin to know about the PAP user logout */
130 void (*pap_logout_hook) __P((void)) = NULL;
132 /* Hook for a plugin to get the PAP password for authenticating us */
133 int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;
136 * This is used to ensure that we don't start an auth-up/down
137 * script while one is already running.
144 static enum script_state auth_state = s_down;
145 static enum script_state auth_script_state = s_down;
146 static pid_t auth_script_pid = 0;
148 static int used_login; /* peer authenticated against login database */
153 bool uselogin = 0; /* Use /etc/passwd for checking PAP */
154 bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */
155 bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */
156 bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */
157 bool usehostname = 0; /* Use hostname for our_name */
158 bool auth_required = 0; /* Always require authentication from peer */
159 bool allow_any_ip = 0; /* Allow peer to use any IP address */
160 bool explicit_remote = 0; /* User specified explicit remote name */
161 char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
163 static char *uafname; /* name of most recent +ua file */
165 /* Bits in auth_pending[] */
166 #define PAP_WITHPEER 1
168 #define CHAP_WITHPEER 4
171 extern char *crypt __P((const char *, const char *));
173 /* Prototypes for procedures local to this file. */
175 static void network_phase __P((int));
176 static void check_idle __P((void *));
177 static void connect_time_expired __P((void *));
178 static int plogin __P((char *, char *, char **));
179 static void plogout __P((void));
180 static int null_login __P((int));
181 static int get_pap_passwd __P((char *));
182 static int have_pap_secret __P((int *));
183 static int have_chap_secret __P((char *, char *, int, int *));
184 static int ip_addr_check __P((u_int32_t, struct permitted_ip *));
185 static int scan_authfile __P((FILE *, char *, char *, char *,
186 struct wordlist **, struct wordlist **,
188 static void free_wordlist __P((struct wordlist *));
189 static void auth_script __P((char *));
190 static void auth_script_done __P((void *));
191 static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
192 static int some_ip_ok __P((struct wordlist *));
193 static int setupapfile __P((char **));
194 static int privgroup __P((char **));
195 static int set_noauth_addr __P((char **));
196 static void check_access __P((FILE *, char *));
197 static int wordlist_count __P((struct wordlist *));
200 * Authentication-related options.
202 option_t auth_options[] = {
203 { "auth", o_bool, &auth_required,
204 "Require authentication from peer", OPT_PRIO | 1 },
205 { "noauth", o_bool, &auth_required,
206 "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
208 { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
209 "Require PAP authentication from peer",
210 OPT_PRIOSUB | 1, &auth_required },
211 { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
212 "Require PAP authentication from peer",
213 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
214 { "require-chap", o_bool, &lcp_wantoptions[0].neg_chap,
215 "Require CHAP authentication from peer",
216 OPT_PRIOSUB | 1, &auth_required },
217 { "+chap", o_bool, &lcp_wantoptions[0].neg_chap,
218 "Require CHAP authentication from peer",
219 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
221 { "refuse-pap", o_bool, &refuse_pap,
222 "Don't agree to auth to peer with PAP", 1 },
223 { "-pap", o_bool, &refuse_pap,
224 "Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
226 { "refuse-chap", o_bool, &refuse_chap,
227 "Don't agree to auth to peer with CHAP", 1 },
228 { "-chap", o_bool, &refuse_chap,
229 "Don't allow CHAP authentication with peer", OPT_ALIAS | 1 },
231 { "name", o_string, our_name,
232 "Set local name for authentication",
233 OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
235 { "+ua", o_special, (void *)setupapfile,
236 "Get PAP user and password from file",
237 OPT_PRIO | OPT_A2STRVAL, &uafname },
239 { "user", o_string, user,
240 "Set name for auth with peer", OPT_PRIO | OPT_STATIC, NULL, MAXNAMELEN },
242 { "password", o_string, passwd,
243 "Password for authenticating us to the peer",
244 OPT_PRIO | OPT_STATIC | OPT_HIDE, NULL, MAXSECRETLEN },
246 { "usehostname", o_bool, &usehostname,
247 "Must use hostname for authentication", 1 },
249 { "remotename", o_string, remote_name,
250 "Set remote name for authentication", OPT_PRIO | OPT_STATIC,
251 &explicit_remote, MAXNAMELEN },
253 { "login", o_bool, &uselogin,
254 "Use system password database for PAP", 1 },
256 { "papcrypt", o_bool, &cryptpap,
257 "PAP passwords are encrypted", 1 },
259 { "privgroup", o_special, (void *)privgroup,
260 "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
262 { "allow-ip", o_special, (void *)set_noauth_addr,
263 "Set IP address(es) which can be used without authentication",
264 OPT_PRIV | OPT_A2LIST },
270 * setupapfile - specifies UPAP info for authenticating with peer.
278 char u[MAXNAMELEN], p[MAXSECRETLEN];
281 lcp_allowoptions[0].neg_upap = 1;
283 /* open user info file */
284 fname = strdup(*argv);
286 novm("+ua file name");
288 ufile = fopen(fname, "r");
291 option_error("unable to open user login data file %s", fname);
294 check_access(ufile, fname);
298 if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
299 || fgets(p, MAXSECRETLEN - 1, ufile) == NULL){
300 option_error("unable to read user login data file %s", fname);
305 /* get rid of newlines */
307 if (l > 0 && u[l-1] == '\n')
310 if (l > 0 && p[l-1] == '\n')
313 if (override_value("user", option_priority, fname))
314 strlcpy(user, u, sizeof(user));
315 if (override_value("passwd", option_priority, fname))
316 strlcpy(passwd, p, sizeof(passwd));
323 * privgroup - allow members of the group to have privileged access.
334 option_error("group %s is unknown", *argv);
337 for (i = 0; i < ngroups; ++i) {
338 if (groups[i] == g->gr_gid) {
348 * set_noauth_addr - set address(es) that can be used without authentication.
349 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
352 set_noauth_addr(argv)
356 int l = strlen(addr) + 1;
359 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
361 novm("allow-ip argument");
362 wp->word = (char *) (wp + 1);
363 wp->next = noauth_addrs;
364 BCOPY(addr, wp->word, l);
371 * An Open on LCP has requested a change from Dead to Establish phase.
372 * Do what's necessary to bring the physical layer up.
381 * LCP has terminated the link; go to the Dead phase and take the
382 * physical layer down.
385 link_terminated(unit)
388 if (phase == PHASE_DEAD)
390 if (pap_logout_hook) {
396 new_phase(PHASE_DEAD);
397 notice("Connection terminated.");
401 * LCP has gone down; it will either die or try to re-establish.
408 struct protent *protp;
411 if (auth_script_state == s_up && auth_script_pid == 0) {
412 update_link_stats(unit);
413 auth_script_state = s_down;
414 auth_script(_PATH_AUTHDOWN);
416 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
417 if (!protp->enabled_flag)
419 if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
420 (*protp->lowerdown)(unit);
421 if (protp->protocol < 0xC000 && protp->close != NULL)
422 (*protp->close)(unit, "LCP down");
426 if (phase != PHASE_DEAD)
427 new_phase(PHASE_TERMINATE);
431 * The link is established.
432 * Proceed to the Dead, Authenticate or Network phase as appropriate.
435 link_established(unit)
439 lcp_options *wo = &lcp_wantoptions[unit];
440 lcp_options *go = &lcp_gotoptions[unit];
441 lcp_options *ho = &lcp_hisoptions[unit];
443 struct protent *protp;
446 * Tell higher-level protocols that LCP is up.
448 for (i = 0; (protp = protocols[i]) != NULL; ++i)
449 if (protp->protocol != PPP_LCP && protp->enabled_flag
450 && protp->lowerup != NULL)
451 (*protp->lowerup)(unit);
453 if (auth_required && !(go->neg_chap || go->neg_upap)) {
455 * We wanted the peer to authenticate itself, and it refused:
456 * if we have some address(es) it can use without auth, fine,
457 * otherwise treat it as though it authenticated with PAP using
458 * a username * of "" and a password of "". If that's not OK,
461 if (noauth_addrs != NULL) {
462 set_allowed_addrs(unit, NULL, NULL);
463 } else if (!wo->neg_upap || uselogin || !null_login(unit)) {
464 warn("peer refused to authenticate: terminating link");
465 lcp_close(unit, "peer refused to authenticate");
466 status = EXIT_PEER_AUTH_FAILED;
471 new_phase(PHASE_AUTHENTICATE);
475 ChapAuthPeer(unit, our_name, go->chap_mdtype);
477 } else if (go->neg_upap) {
482 ChapAuthWithPeer(unit, user, ho->chap_mdtype);
483 auth |= CHAP_WITHPEER;
484 } else if (ho->neg_upap) {
485 if (passwd[0] == 0) {
486 passwd_from_file = 1;
487 if (!get_pap_passwd(passwd))
488 error("No secret found for PAP login");
490 upap_authwithpeer(unit, user, passwd);
491 auth |= PAP_WITHPEER;
493 auth_pending[unit] = auth;
500 * Proceed to the network phase.
506 lcp_options *go = &lcp_gotoptions[unit];
509 * If the peer had to authenticate, run the auth-up script now.
511 if (go->neg_chap || go->neg_upap) {
513 if (auth_script_state == s_down && auth_script_pid == 0) {
514 auth_script_state = s_up;
515 auth_script(_PATH_AUTHUP);
521 * If we negotiated callback, do it now.
524 new_phase(PHASE_CALLBACK);
525 (*cbcp_protent.open)(unit);
531 * Process extra options from the secrets file
534 options_from_list(extra_options, 1);
535 free_wordlist(extra_options);
545 struct protent *protp;
547 new_phase(PHASE_NETWORK);
549 #ifdef HAVE_MULTILINK
551 if (mp_join_bundle()) {
552 if (updetach && !nodetach)
557 #endif /* HAVE_MULTILINK */
561 set_filters(&pass_filter, &active_filter);
563 for (i = 0; (protp = protocols[i]) != NULL; ++i)
564 if (protp->protocol < 0xC000 && protp->enabled_flag
565 && protp->open != NULL) {
567 if (protp->protocol != PPP_CCP)
571 if (num_np_open == 0)
573 lcp_close(0, "No network protocols running");
577 * The peer has failed to authenticate himself using `protocol'.
580 auth_peer_fail(unit, protocol)
584 * Authentication failure: take the link down
586 lcp_close(unit, "Authentication failed");
587 status = EXIT_PEER_AUTH_FAILED;
591 * The peer has been successfully authenticated using `protocol'.
594 auth_peer_success(unit, protocol, name, namelen)
609 warn("auth_peer_success: unknown protocol %x", protocol);
614 * Save the authenticated name of the peer for later.
616 if (namelen > sizeof(peer_authname) - 1)
617 namelen = sizeof(peer_authname) - 1;
618 BCOPY(name, peer_authname, namelen);
619 peer_authname[namelen] = 0;
620 script_setenv("PEERNAME", peer_authname, 0);
623 * If there is no more authentication still to be done,
624 * proceed to the network (or callback) phase.
626 if ((auth_pending[unit] &= ~bit) == 0)
631 * We have failed to authenticate ourselves to the peer using `protocol'.
634 auth_withpeer_fail(unit, protocol)
637 if (passwd_from_file)
638 BZERO(passwd, MAXSECRETLEN);
640 * We've failed to authenticate ourselves to our peer.
641 * Some servers keep sending CHAP challenges, but there
642 * is no point in persisting without any way to get updated
643 * authentication secrets.
645 lcp_close(unit, "Failed to authenticate ourselves to peer");
646 status = EXIT_AUTH_TOPEER_FAILED;
650 * We have successfully authenticated ourselves with the peer using `protocol'.
653 auth_withpeer_success(unit, protocol)
663 if (passwd_from_file)
664 BZERO(passwd, MAXSECRETLEN);
668 warn("auth_withpeer_success: unknown protocol %x", protocol);
673 * If there is no more authentication still being done,
674 * proceed to the network (or callback) phase.
676 if ((auth_pending[unit] &= ~bit) == 0)
682 * np_up - a network protocol has come up.
690 if (num_np_up == 0) {
692 * At this point we consider that the link has come up successfully.
696 new_phase(PHASE_RUNNING);
698 if (idle_time_hook != 0)
699 tlim = (*idle_time_hook)(NULL);
701 tlim = idle_time_limit;
703 TIMEOUT(check_idle, NULL, tlim);
706 * Set a timeout to close the connection once the maximum
707 * connect time has expired.
710 TIMEOUT(connect_time_expired, 0, maxconnect);
713 * Detach now, if the updetach option was given.
715 if (updetach && !nodetach)
722 * np_down - a network protocol has gone down.
728 if (--num_np_up == 0) {
729 UNTIMEOUT(check_idle, NULL);
730 new_phase(PHASE_NETWORK);
735 * np_finished - a network protocol has finished using the link.
738 np_finished(unit, proto)
741 if (--num_np_open <= 0) {
742 /* no further use for the link: shut up shop. */
743 lcp_close(0, "No network protocols running");
748 * check_idle - check whether the link has been idle for long
749 * enough that we can shut it down.
755 struct ppp_idle idle;
759 if (!get_idle_time(0, &idle))
761 if (idle_time_hook != 0) {
762 tlim = idle_time_hook(&idle);
764 itime = MIN(idle.xmit_idle, idle.recv_idle);
765 tlim = idle_time_limit - itime;
768 /* link is idle: shut it down. */
769 notice("Terminating connection due to lack of activity.");
770 lcp_close(0, "Link inactive");
772 status = EXIT_IDLE_TIMEOUT;
774 TIMEOUT(check_idle, NULL, tlim);
779 * connect_time_expired - log a message and close the connection.
782 connect_time_expired(arg)
785 info("Connect time expired");
786 lcp_close(0, "Connect time expired"); /* Close connection */
787 status = EXIT_CONNECT_TIME;
791 * auth_check_options - called to check authentication options.
796 lcp_options *wo = &lcp_wantoptions[0];
800 /* Default our_name to hostname, and user to our_name */
801 if (our_name[0] == 0 || usehostname)
802 strlcpy(our_name, hostname, sizeof(our_name));
804 strlcpy(user, our_name, sizeof(user));
807 * If we have a default route, require the peer to authenticate
808 * unless the noauth option was given or the real user is root.
810 if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
815 /* If authentication is required, ask peer for CHAP or PAP. */
818 if (!wo->neg_chap && !wo->neg_upap) {
828 * Check whether we have appropriate secrets to use
829 * to authenticate the peer.
832 can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
833 if (!can_auth && wo->neg_chap) {
834 can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
835 our_name, 1, &lacks_ip);
838 if (auth_required && !can_auth && noauth_addrs == NULL) {
841 "By default the remote system is required to authenticate itself");
843 "(because this system has a default route to the internet)");
844 } else if (explicit_remote)
846 "The remote system (%s) is required to authenticate itself",
850 "The remote system is required to authenticate itself");
852 "but I couldn't find any suitable secret (password) for it to use to do so.");
855 "(None of the available passwords would let it use an IP address.)");
862 * auth_reset - called when LCP is starting negotiations to recheck
863 * authentication options, i.e. whether we have appropriate secrets
864 * to use for authenticating ourselves and/or the peer.
870 lcp_options *go = &lcp_gotoptions[unit];
871 lcp_options *ao = &lcp_allowoptions[0];
873 ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
874 ao->neg_chap = !refuse_chap
876 || have_chap_secret(user, (explicit_remote? remote_name: NULL),
879 if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
882 if (!have_chap_secret((explicit_remote? remote_name: NULL),
890 * check_passwd - Check the user name and passwd against the PAP secrets
891 * file. If requested, also check against the system password database,
892 * and login the user if OK.
895 * UPAP_AUTHNAK: Authentication failed.
896 * UPAP_AUTHACK: Authentication succeeded.
897 * In either case, msg points to an appropriate message.
900 check_passwd(unit, auser, userlen, apasswd, passwdlen, msg)
911 struct wordlist *addrs = NULL, *opts = NULL;
912 char passwd[256], user[256];
913 char secret[MAXWORDLEN];
914 static int attempts = 0;
917 * Make copies of apasswd and auser, then null-terminate them.
918 * If there are unprintable characters in the password, make
921 slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
922 slprintf(user, sizeof(user), "%.*v", userlen, auser);
926 * Check if a plugin wants to handle this.
929 ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
932 set_allowed_addrs(unit, addrs, opts);
933 BZERO(passwd, sizeof(passwd));
935 free_wordlist(addrs);
936 return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
941 * Open the file of pap secrets and scan for a suitable secret
942 * for authenticating this user.
944 filename = _PATH_UPAPFILE;
947 f = fopen(filename, "r");
949 error("Can't open PAP password file %s: %m", filename);
952 check_access(f, filename);
953 if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename) < 0) {
954 warn("no PAP secret found for %s", user);
957 * If the secret is "@login", it means to check
958 * the password against the login database.
960 int login_secret = strcmp(secret, "@login") == 0;
962 if (uselogin || login_secret) {
963 /* login option or secret is @login */
964 ret = plogin(user, passwd, msg);
965 if (ret == UPAP_AUTHNAK)
966 warn("PAP login failure for %s", user);
970 if (secret[0] != 0 && !login_secret) {
971 /* password given in pap-secrets - must match */
972 if ((cryptpap || strcmp(passwd, secret) != 0)
973 && strcmp(crypt(passwd, secret), secret) != 0) {
975 warn("PAP authentication failure for %s", user);
982 if (ret == UPAP_AUTHNAK) {
984 *msg = "Login incorrect";
986 * XXX can we ever get here more than once??
987 * Frustrate passwd stealer programs.
988 * Allow 10 tries, but start backing off after 3 (stolen from login).
989 * On 10'th, drop the connection.
991 if (attempts++ >= 10) {
992 warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
993 lcp_close(unit, "login failed");
996 sleep((u_int) (attempts - 3) * 5);
1001 attempts = 0; /* Reset count */
1004 set_allowed_addrs(unit, addrs, opts);
1008 free_wordlist(addrs);
1009 BZERO(passwd, sizeof(passwd));
1010 BZERO(secret, sizeof(secret));
1016 * This function is needed for PAM.
1020 /* Static variables used to communicate between the conversation function
1021 * and the server_login function
1023 static char *PAM_username;
1024 static char *PAM_password;
1025 static int PAM_error = 0;
1026 static pam_handle_t *pamh = NULL;
1028 /* PAM conversation function
1029 * Here we assume (for now, at least) that echo on means login name, and
1030 * echo off means password.
1033 static int PAM_conv (int num_msg, const struct pam_message **msg,
1034 struct pam_response **resp, void *appdata_ptr)
1037 struct pam_response *reply = NULL;
1039 #define COPY_STRING(s) (s) ? strdup(s) : NULL
1041 reply = malloc(sizeof(struct pam_response) * num_msg);
1042 if (!reply) return PAM_CONV_ERR;
1044 for (replies = 0; replies < num_msg; replies++) {
1045 switch (msg[replies]->msg_style) {
1046 case PAM_PROMPT_ECHO_ON:
1047 reply[replies].resp_retcode = PAM_SUCCESS;
1048 reply[replies].resp = COPY_STRING(PAM_username);
1049 /* PAM frees resp */
1051 case PAM_PROMPT_ECHO_OFF:
1052 reply[replies].resp_retcode = PAM_SUCCESS;
1053 reply[replies].resp = COPY_STRING(PAM_password);
1054 /* PAM frees resp */
1059 /* ignore it, but pam still wants a NULL response... */
1060 reply[replies].resp_retcode = PAM_SUCCESS;
1061 reply[replies].resp = NULL;
1064 /* Must be an error of some sort... */
1067 return PAM_CONV_ERR;
1074 static struct pam_conv PAM_conversation = {
1078 #endif /* USE_PAM */
1081 * plogin - Check the user name and password against the system
1082 * password database, and login the user if OK.
1085 * UPAP_AUTHNAK: Login failed.
1086 * UPAP_AUTHACK: Login succeeded.
1087 * In either case, msg points to an appropriate message.
1091 plogin(user, passwd, msg)
1101 pam_error = pam_start ("ppp", user, &PAM_conversation, &pamh);
1102 if (pam_error != PAM_SUCCESS) {
1103 *msg = (char *) pam_strerror (pamh, pam_error);
1105 return UPAP_AUTHNAK;
1108 * Define the fields for the credential validation
1111 PAM_username = user;
1112 PAM_password = passwd;
1114 pam_set_item (pamh, PAM_TTY, devnam); /* this might be useful to some modules */
1119 pam_error = pam_authenticate (pamh, PAM_SILENT);
1120 if (pam_error == PAM_SUCCESS && !PAM_error) {
1121 pam_error = pam_acct_mgmt (pamh, PAM_SILENT);
1122 if (pam_error == PAM_SUCCESS)
1123 pam_open_session (pamh, PAM_SILENT);
1126 *msg = (char *) pam_strerror (pamh, pam_error);
1131 reopen_log(); /* apparently the PAM stuff does closelog() */
1132 PAM_username = NULL;
1133 PAM_password = NULL;
1134 if (pam_error != PAM_SUCCESS)
1135 return UPAP_AUTHNAK;
1136 #else /* #ifdef USE_PAM */
1139 * Use the non-PAM methods directly
1144 struct spwd *getspnam();
1146 struct passwd *pw = getpwnam(user);
1150 return (UPAP_AUTHNAK);
1153 spwd = getspnam(user);
1156 /* check the age of the password entry */
1157 long now = time(NULL) / 86400L;
1159 if ((spwd->sp_expire > 0 && now >= spwd->sp_expire)
1160 || ((spwd->sp_max >= 0 && spwd->sp_max < 10000)
1161 && spwd->sp_lstchg >= 0
1162 && now >= spwd->sp_lstchg + spwd->sp_max)) {
1163 warn("Password for %s has expired", user);
1164 return (UPAP_AUTHNAK);
1166 pw->pw_passwd = spwd->sp_pwdp;
1171 * If no passwd, don't let them login.
1173 if (pw->pw_passwd == NULL || strlen(pw->pw_passwd) < 2
1174 || strcmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd) != 0)
1175 return (UPAP_AUTHNAK);
1177 #endif /* #ifdef USE_PAM */
1180 * Write a wtmp entry for this user.
1184 if (strncmp(tty, "/dev/", 5) == 0)
1186 logwtmp(tty, user, remote_name); /* Add wtmp login entry */
1188 #if defined(_PATH_LASTLOG) && !defined(USE_PAM)
1189 if (pw != (struct passwd *)NULL) {
1193 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
1194 (void)lseek(fd, (off_t)(pw->pw_uid * sizeof(ll)), SEEK_SET);
1195 memset((void *)&ll, 0, sizeof(ll));
1196 (void)time(&ll.ll_time);
1197 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
1198 (void)write(fd, (char *)&ll, sizeof(ll));
1202 #endif /* _PATH_LASTLOG and not USE_PAM */
1204 info("user %s logged in", user);
1207 return (UPAP_AUTHACK);
1211 * plogout - Logout the user.
1220 pam_error = pam_close_session (pamh, PAM_SILENT);
1221 pam_end (pamh, pam_error);
1224 /* Apparently the pam stuff does closelog(). */
1226 #else /* ! USE_PAM */
1230 if (strncmp(tty, "/dev/", 5) == 0)
1232 logwtmp(tty, "", ""); /* Wipe out utmp logout entry */
1233 #endif /* ! USE_PAM */
1239 * null_login - Check if a username of "" and a password of "" are
1240 * acceptable, and iff so, set the list of acceptable IP addresses
1250 struct wordlist *addrs, *opts;
1251 char secret[MAXWORDLEN];
1254 * Open the file of pap secrets and scan for a suitable secret.
1256 filename = _PATH_UPAPFILE;
1258 f = fopen(filename, "r");
1261 check_access(f, filename);
1263 i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename);
1264 ret = i >= 0 && secret[0] == 0;
1265 BZERO(secret, sizeof(secret));
1268 set_allowed_addrs(unit, addrs, opts);
1270 free_wordlist(opts);
1272 free_wordlist(addrs);
1280 * get_pap_passwd - get a password for authenticating ourselves with
1281 * our peer using PAP. Returns 1 on success, 0 if no suitable password
1283 * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
1286 get_pap_passwd(passwd)
1292 char secret[MAXWORDLEN];
1295 * Check whether a plugin wants to supply this.
1297 if (pap_passwd_hook) {
1298 ret = (*pap_passwd_hook)(user, passwd);
1303 filename = _PATH_UPAPFILE;
1304 f = fopen(filename, "r");
1307 check_access(f, filename);
1308 ret = scan_authfile(f, user,
1309 (remote_name[0]? remote_name: NULL),
1310 secret, NULL, NULL, filename);
1315 strlcpy(passwd, secret, MAXSECRETLEN);
1316 BZERO(secret, sizeof(secret));
1322 * have_pap_secret - check whether we have a PAP file with any
1323 * secrets that we could possibly use for authenticating the peer.
1326 have_pap_secret(lacks_ipp)
1332 struct wordlist *addrs;
1334 /* let the plugin decide, if there is one */
1335 if (pap_check_hook) {
1336 ret = (*pap_check_hook)();
1341 filename = _PATH_UPAPFILE;
1342 f = fopen(filename, "r");
1346 ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
1347 NULL, &addrs, NULL, filename);
1349 if (ret >= 0 && !some_ip_ok(addrs)) {
1355 free_wordlist(addrs);
1362 * have_chap_secret - check whether we have a CHAP file with a
1363 * secret that we could possibly use for authenticating `client'
1364 * on `server'. Either can be the null string, meaning we don't
1365 * know the identity yet.
1368 have_chap_secret(client, server, need_ip, lacks_ipp)
1377 struct wordlist *addrs;
1379 filename = _PATH_CHAPFILE;
1380 f = fopen(filename, "r");
1384 if (client != NULL && client[0] == 0)
1386 else if (server != NULL && server[0] == 0)
1389 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename);
1391 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1397 free_wordlist(addrs);
1404 * get_secret - open the CHAP secret file and return the secret
1405 * for authenticating the given client on the given server.
1406 * (We could be either client or server).
1409 get_secret(unit, client, server, secret, secret_len, am_server)
1420 struct wordlist *addrs, *opts;
1421 char secbuf[MAXWORDLEN];
1423 if (!am_server && passwd[0] != 0) {
1424 strlcpy(secbuf, passwd, sizeof(secbuf));
1426 filename = _PATH_CHAPFILE;
1430 f = fopen(filename, "r");
1432 error("Can't open chap secret file %s: %m", filename);
1435 check_access(f, filename);
1437 ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename);
1443 set_allowed_addrs(unit, addrs, opts);
1445 free_wordlist(opts);
1447 free_wordlist(addrs);
1450 len = strlen(secbuf);
1451 if (len > MAXSECRETLEN) {
1452 error("Secret for %s on %s is too long", client, server);
1455 BCOPY(secbuf, secret, len);
1456 BZERO(secbuf, sizeof(secbuf));
1463 * set_allowed_addrs() - set the list of allowed addresses.
1464 * Also looks for `--' indicating options to apply for this peer
1465 * and leaves the following words in extra_options.
1468 set_allowed_addrs(unit, addrs, opts)
1470 struct wordlist *addrs;
1471 struct wordlist *opts;
1474 struct wordlist *ap, **plink;
1475 struct permitted_ip *ip;
1476 char *ptr_word, *ptr_mask;
1479 u_int32_t a, mask, ah, offset;
1480 struct ipcp_options *wo = &ipcp_wantoptions[unit];
1481 u_int32_t suggested_ip = 0;
1483 if (addresses[unit] != NULL)
1484 free(addresses[unit]);
1485 addresses[unit] = NULL;
1486 if (extra_options != NULL)
1487 free_wordlist(extra_options);
1488 extra_options = opts;
1491 * Count the number of IP addresses given.
1493 n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
1496 ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
1500 /* temporarily append the noauth_addrs list to addrs */
1501 for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
1503 *plink = noauth_addrs;
1506 for (ap = addrs; ap != NULL; ap = ap->next) {
1507 /* "-" means no addresses authorized, "*" means any address allowed */
1508 ptr_word = ap->word;
1509 if (strcmp(ptr_word, "-") == 0)
1511 if (strcmp(ptr_word, "*") == 0) {
1513 ip[n].base = ip[n].mask = 0;
1519 if (*ptr_word == '!') {
1524 mask = ~ (u_int32_t) 0;
1526 ptr_mask = strchr (ptr_word, '/');
1527 if (ptr_mask != NULL) {
1531 bit_count = (int) strtol (ptr_mask+1, &endp, 10);
1532 if (bit_count <= 0 || bit_count > 32) {
1533 warn("invalid address length %v in auth. address list",
1537 bit_count = 32 - bit_count; /* # bits in host part */
1539 offset = ifunit + 1;
1543 warn("invalid address length syntax: %v", ptr_mask+1);
1550 hp = gethostbyname(ptr_word);
1551 if (hp != NULL && hp->h_addrtype == AF_INET) {
1552 a = *(u_int32_t *)hp->h_addr;
1554 np = getnetbyname (ptr_word);
1555 if (np != NULL && np->n_addrtype == AF_INET) {
1556 a = htonl (*(u_int32_t *)np->n_net);
1557 if (ptr_mask == NULL) {
1558 /* calculate appropriate mask for net */
1561 mask = IN_CLASSA_NET;
1562 else if (IN_CLASSB(ah))
1563 mask = IN_CLASSB_NET;
1564 else if (IN_CLASSC(ah))
1565 mask = IN_CLASSC_NET;
1568 a = inet_addr (ptr_word);
1572 if (ptr_mask != NULL)
1575 if (a == (u_int32_t)-1L) {
1576 warn("unknown host %s in auth. address list", ap->word);
1580 if (offset >= ~mask) {
1581 warn("interface unit %d too large for subnet %v",
1585 a = htonl((ntohl(a) & mask) + offset);
1586 mask = ~(u_int32_t)0;
1588 ip[n].mask = htonl(mask);
1589 ip[n].base = a & ip[n].mask;
1591 if (~mask == 0 && suggested_ip == 0)
1596 ip[n].permit = 0; /* make the last entry forbid all addresses */
1597 ip[n].base = 0; /* to terminate the list */
1600 addresses[unit] = ip;
1603 * If the address given for the peer isn't authorized, or if
1604 * the user hasn't given one, AND there is an authorized address
1605 * which is a single host, then use that if we find one.
1607 if (suggested_ip != 0
1608 && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr)))
1609 wo->hisaddr = suggested_ip;
1613 * auth_ip_addr - check whether the peer is authorized to use
1614 * a given IP address. Returns 1 if authorized, 0 otherwise.
1617 auth_ip_addr(unit, addr)
1623 /* don't allow loopback or multicast address */
1624 if (bad_ip_adrs(addr))
1627 if (addresses[unit] != NULL) {
1628 ok = ip_addr_check(addr, addresses[unit]);
1633 return 0; /* no addresses authorized */
1634 return allow_any_ip || privileged || !have_route_to(addr);
1638 ip_addr_check(addr, addrs)
1640 struct permitted_ip *addrs;
1643 if ((addr & addrs->mask) == addrs->base)
1644 return addrs->permit;
1648 * bad_ip_adrs - return 1 if the IP address is one we don't want
1649 * to use, such as an address in the loopback net or a multicast address.
1650 * addr is in network byte order.
1657 return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
1658 || IN_MULTICAST(addr) || IN_BADCLASS(addr);
1662 * some_ip_ok - check a wordlist to see if it authorizes any
1667 struct wordlist *addrs;
1669 for (; addrs != 0; addrs = addrs->next) {
1670 if (addrs->word[0] == '-')
1672 if (addrs->word[0] != '!')
1673 return 1; /* some IP address is allowed */
1679 * check_access - complain if a secret file has too-liberal permissions.
1682 check_access(f, filename)
1688 if (fstat(fileno(f), &sbuf) < 0) {
1689 warn("cannot stat secret file %s: %m", filename);
1690 } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
1691 warn("Warning - secret file %s has world and/or group access",
1698 * scan_authfile - Scan an authorization file for a secret suitable
1699 * for authenticating `client' on `server'. The return value is -1
1700 * if no secret is found, otherwise >= 0. The return value has
1701 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
1702 * NONWILD_SERVER set if the secret didn't have "*" for the server.
1703 * Any following words on the line up to a "--" (i.e. address authorization
1704 * info) are placed in a wordlist and returned in *addrs. Any
1705 * following words (extra options) are placed in a wordlist and
1706 * returned in *opts.
1707 * We assume secret is NULL or points to MAXWORDLEN bytes of space.
1710 scan_authfile(f, client, server, secret, addrs, opts, filename)
1715 struct wordlist **addrs;
1716 struct wordlist **opts;
1720 int got_flag, best_flag;
1722 struct wordlist *ap, *addr_list, *alist, **app;
1723 char word[MAXWORDLEN];
1724 char atfile[MAXWORDLEN];
1725 char lsecret[MAXWORDLEN];
1732 if (!getword(f, word, &newline, filename))
1733 return -1; /* file is empty??? */
1738 * Skip until we find a word at the start of a line.
1740 while (!newline && getword(f, word, &newline, filename))
1743 break; /* got to end of file */
1746 * Got a client - check if it's a match or a wildcard.
1749 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
1754 got_flag = NONWILD_CLIENT;
1757 * Now get a server and check if it matches.
1759 if (!getword(f, word, &newline, filename))
1763 if (!ISWILD(word)) {
1764 if (server != NULL && strcmp(word, server) != 0)
1766 got_flag |= NONWILD_SERVER;
1770 * Got some sort of a match - see if it's better than what
1773 if (got_flag <= best_flag)
1779 if (!getword(f, word, &newline, filename))
1784 if (secret != NULL) {
1786 * Special syntax: @/pathname means read secret from file.
1788 if (word[0] == '@' && word[1] == '/') {
1789 strlcpy(atfile, word+1, sizeof(atfile));
1790 if ((sf = fopen(atfile, "r")) == NULL) {
1791 warn("can't open indirect secret file %s", atfile);
1794 check_access(sf, atfile);
1795 if (!getword(sf, word, &xxx, atfile)) {
1796 warn("no secret in indirect secret file %s", atfile);
1802 strlcpy(lsecret, word, sizeof(lsecret));
1806 * Now read address authorization info and make a wordlist.
1810 if (!getword(f, word, &newline, filename) || newline)
1812 ap = (struct wordlist *)
1813 malloc(sizeof(struct wordlist) + strlen(word) + 1);
1815 novm("authorized addresses");
1816 ap->word = (char *) (ap + 1);
1817 strcpy(ap->word, word);
1824 * This is the best so far; remember it.
1826 best_flag = got_flag;
1828 free_wordlist(addr_list);
1831 strlcpy(secret, lsecret, MAXWORDLEN);
1837 /* scan for a -- word indicating the start of options */
1838 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
1839 if (strcmp(ap->word, "--") == 0)
1841 /* ap = start of options */
1843 ap = ap->next; /* first option */
1844 free(*app); /* free the "--" word */
1845 *app = NULL; /* terminate addr list */
1849 else if (ap != NULL)
1853 else if (addr_list != NULL)
1854 free_wordlist(addr_list);
1860 * wordlist_count - return the number of items in a wordlist
1864 struct wordlist *wp;
1868 for (n = 0; wp != NULL; wp = wp->next)
1874 * free_wordlist - release memory allocated for a wordlist.
1878 struct wordlist *wp;
1880 struct wordlist *next;
1882 while (wp != NULL) {
1890 * auth_script_done - called when the auth-up or auth-down script
1894 auth_script_done(arg)
1897 auth_script_pid = 0;
1898 switch (auth_script_state) {
1900 if (auth_state == s_down) {
1901 auth_script_state = s_down;
1902 auth_script(_PATH_AUTHDOWN);
1906 if (auth_state == s_up) {
1907 auth_script_state = s_up;
1908 auth_script(_PATH_AUTHUP);
1915 * auth_script - execute a script with arguments
1916 * interface-name peer-name real-user tty speed
1928 if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
1929 user_name = pw->pw_name;
1931 slprintf(struid, sizeof(struid), "%d", getuid());
1934 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
1938 argv[2] = peer_authname;
1939 argv[3] = user_name;
1944 auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL);