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 1.73 2002/01/22 16:02:58 dfs 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
78 #include "pathnames.h"
80 static const char rcsid[] = RCSID;
82 /* Bits in scan_authfile return value */
83 #define NONWILD_SERVER 1
84 #define NONWILD_CLIENT 2
86 #define ISWILD(word) (word[0] == '*' && word[1] == 0)
88 /* The name by which the peer authenticated itself to us. */
89 char peer_authname[MAXNAMELEN];
91 /* Records which authentication operations haven't completed yet. */
92 static int auth_pending[NUM_PPP];
94 /* Set if we have successfully called plogin() */
97 /* List of addresses which the peer may use. */
98 static struct permitted_ip *addresses[NUM_PPP];
100 /* Wordlist giving addresses which the peer may use
101 without authenticating itself. */
102 static struct wordlist *noauth_addrs;
104 /* Extra options to apply, from the secrets file entry for the peer. */
105 static struct wordlist *extra_options;
107 /* Number of network protocols which we have opened. */
108 static int num_np_open;
110 /* Number of network protocols which have come up. */
111 static int num_np_up;
113 /* Set if we got the contents of passwd[] from the pap-secrets file. */
114 static int passwd_from_file;
116 /* Set if we require authentication only because we have a default route. */
117 static bool default_auth;
119 /* Hook to enable a plugin to control the idle time limit */
120 int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;
122 /* Hook for a plugin to say whether we can possibly authenticate any peer */
123 int (*pap_check_hook) __P((void)) = NULL;
125 /* Hook for a plugin to check the PAP user and password */
126 int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
127 struct wordlist **paddrs,
128 struct wordlist **popts)) = NULL;
130 /* Hook for a plugin to know about the PAP user logout */
131 void (*pap_logout_hook) __P((void)) = NULL;
133 /* Hook for a plugin to get the PAP password for authenticating us */
134 int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;
136 /* Hook for a plugin to say whether it is OK if the peer
137 refuses to authenticate. */
138 int (*null_auth_hook) __P((struct wordlist **paddrs,
139 struct wordlist **popts)) = NULL;
141 int (*allowed_address_hook) __P((u_int32_t addr)) = NULL;
143 /* A notifier for when the peer has authenticated itself,
144 and we are proceeding to the network phase. */
145 struct notifier *auth_up_notifier = NULL;
147 /* A notifier for when the link goes down. */
148 struct notifier *link_down_notifier = NULL;
151 * This is used to ensure that we don't start an auth-up/down
152 * script while one is already running.
159 static enum script_state auth_state = s_down;
160 static enum script_state auth_script_state = s_down;
161 static pid_t auth_script_pid = 0;
163 static int used_login; /* peer authenticated against login database */
168 bool uselogin = 0; /* Use /etc/passwd for checking PAP */
169 bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */
170 bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */
171 bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */
172 bool usehostname = 0; /* Use hostname for our_name */
173 bool auth_required = 0; /* Always require authentication from peer */
174 bool allow_any_ip = 0; /* Allow peer to use any IP address */
175 bool explicit_remote = 0; /* User specified explicit remote name */
176 char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
178 static char *uafname; /* name of most recent +ua file */
180 /* Bits in auth_pending[] */
181 #define PAP_WITHPEER 1
183 #define CHAP_WITHPEER 4
186 extern char *crypt __P((const char *, const char *));
188 /* Prototypes for procedures local to this file. */
190 static void network_phase __P((int));
191 static void check_idle __P((void *));
192 static void connect_time_expired __P((void *));
193 static int plogin __P((char *, char *, char **));
194 static void plogout __P((void));
195 static int null_login __P((int));
196 static int get_pap_passwd __P((char *));
197 static int have_pap_secret __P((int *));
198 static int have_chap_secret __P((char *, char *, int, int *));
199 static int ip_addr_check __P((u_int32_t, struct permitted_ip *));
200 static int scan_authfile __P((FILE *, char *, char *, char *,
201 struct wordlist **, struct wordlist **,
203 static void free_wordlist __P((struct wordlist *));
204 static void auth_script __P((char *));
205 static void auth_script_done __P((void *));
206 static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
207 static int some_ip_ok __P((struct wordlist *));
208 static int setupapfile __P((char **));
209 static int privgroup __P((char **));
210 static int set_noauth_addr __P((char **));
211 static void check_access __P((FILE *, char *));
212 static int wordlist_count __P((struct wordlist *));
215 * Authentication-related options.
217 option_t auth_options[] = {
218 { "auth", o_bool, &auth_required,
219 "Require authentication from peer", OPT_PRIO | 1 },
220 { "noauth", o_bool, &auth_required,
221 "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
223 { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
224 "Require PAP authentication from peer",
225 OPT_PRIOSUB | 1, &auth_required },
226 { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
227 "Require PAP authentication from peer",
228 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
229 { "require-chap", o_bool, &lcp_wantoptions[0].neg_chap,
230 "Require CHAP authentication from peer",
231 OPT_PRIOSUB | 1, &auth_required },
232 { "+chap", o_bool, &lcp_wantoptions[0].neg_chap,
233 "Require CHAP authentication from peer",
234 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
236 { "refuse-pap", o_bool, &refuse_pap,
237 "Don't agree to auth to peer with PAP", 1 },
238 { "-pap", o_bool, &refuse_pap,
239 "Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
241 { "refuse-chap", o_bool, &refuse_chap,
242 "Don't agree to auth to peer with CHAP", 1 },
243 { "-chap", o_bool, &refuse_chap,
244 "Don't allow CHAP authentication with peer", OPT_ALIAS | 1 },
246 { "name", o_string, our_name,
247 "Set local name for authentication",
248 OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
250 { "+ua", o_special, (void *)setupapfile,
251 "Get PAP user and password from file",
252 OPT_PRIO | OPT_A2STRVAL, &uafname },
254 { "user", o_string, user,
255 "Set name for auth with peer", OPT_PRIO | OPT_STATIC, NULL, MAXNAMELEN },
257 { "password", o_string, passwd,
258 "Password for authenticating us to the peer",
259 OPT_PRIO | OPT_STATIC | OPT_HIDE, NULL, MAXSECRETLEN },
261 { "usehostname", o_bool, &usehostname,
262 "Must use hostname for authentication", 1 },
264 { "remotename", o_string, remote_name,
265 "Set remote name for authentication", OPT_PRIO | OPT_STATIC,
266 &explicit_remote, MAXNAMELEN },
268 { "login", o_bool, &uselogin,
269 "Use system password database for PAP", 1 },
271 { "papcrypt", o_bool, &cryptpap,
272 "PAP passwords are encrypted", 1 },
274 { "privgroup", o_special, (void *)privgroup,
275 "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
277 { "allow-ip", o_special, (void *)set_noauth_addr,
278 "Set IP address(es) which can be used without authentication",
279 OPT_PRIV | OPT_A2LIST },
285 * setupapfile - specifies UPAP info for authenticating with peer.
293 char u[MAXNAMELEN], p[MAXSECRETLEN];
296 lcp_allowoptions[0].neg_upap = 1;
298 /* open user info file */
299 fname = strdup(*argv);
301 novm("+ua file name");
303 ufile = fopen(fname, "r");
306 option_error("unable to open user login data file %s", fname);
309 check_access(ufile, fname);
313 if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
314 || fgets(p, MAXSECRETLEN - 1, ufile) == NULL){
315 option_error("unable to read user login data file %s", fname);
320 /* get rid of newlines */
322 if (l > 0 && u[l-1] == '\n')
325 if (l > 0 && p[l-1] == '\n')
328 if (override_value("user", option_priority, fname))
329 strlcpy(user, u, sizeof(user));
330 if (override_value("passwd", option_priority, fname))
331 strlcpy(passwd, p, sizeof(passwd));
338 * privgroup - allow members of the group to have privileged access.
349 option_error("group %s is unknown", *argv);
352 for (i = 0; i < ngroups; ++i) {
353 if (groups[i] == g->gr_gid) {
363 * set_noauth_addr - set address(es) that can be used without authentication.
364 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
367 set_noauth_addr(argv)
371 int l = strlen(addr) + 1;
374 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
376 novm("allow-ip argument");
377 wp->word = (char *) (wp + 1);
378 wp->next = noauth_addrs;
379 BCOPY(addr, wp->word, l);
386 * An Open on LCP has requested a change from Dead to Establish phase.
387 * Do what's necessary to bring the physical layer up.
396 * LCP has terminated the link; go to the Dead phase and take the
397 * physical layer down.
400 link_terminated(unit)
403 if (phase == PHASE_DEAD)
405 if (pap_logout_hook) {
411 new_phase(PHASE_DEAD);
412 notice("Connection terminated.");
416 * LCP has gone down; it will either die or try to re-establish.
423 struct protent *protp;
425 notify(link_down_notifier, 0);
427 if (auth_script_state == s_up && auth_script_pid == 0) {
428 update_link_stats(unit);
429 auth_script_state = s_down;
430 auth_script(_PATH_AUTHDOWN);
432 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
433 if (!protp->enabled_flag)
435 if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
436 (*protp->lowerdown)(unit);
437 if (protp->protocol < 0xC000 && protp->close != NULL)
438 (*protp->close)(unit, "LCP down");
442 if (phase != PHASE_DEAD)
443 new_phase(PHASE_ESTABLISH);
447 * The link is established.
448 * Proceed to the Dead, Authenticate or Network phase as appropriate.
451 link_established(unit)
455 lcp_options *wo = &lcp_wantoptions[unit];
456 lcp_options *go = &lcp_gotoptions[unit];
457 lcp_options *ho = &lcp_hisoptions[unit];
459 struct protent *protp;
462 * Tell higher-level protocols that LCP is up.
464 for (i = 0; (protp = protocols[i]) != NULL; ++i)
465 if (protp->protocol != PPP_LCP && protp->enabled_flag
466 && protp->lowerup != NULL)
467 (*protp->lowerup)(unit);
469 if (auth_required && !(go->neg_chap || go->neg_upap)) {
471 * We wanted the peer to authenticate itself, and it refused:
472 * if we have some address(es) it can use without auth, fine,
473 * otherwise treat it as though it authenticated with PAP using
474 * a username * of "" and a password of "". If that's not OK,
477 if (noauth_addrs != NULL) {
478 set_allowed_addrs(unit, NULL, NULL);
479 } else if (!wo->neg_upap || uselogin || !null_login(unit)) {
480 warn("peer refused to authenticate: terminating link");
481 lcp_close(unit, "peer refused to authenticate");
482 status = EXIT_PEER_AUTH_FAILED;
487 new_phase(PHASE_AUTHENTICATE);
491 ChapAuthPeer(unit, our_name, go->chap_mdtype);
493 } else if (go->neg_upap) {
498 ChapAuthWithPeer(unit, user, ho->chap_mdtype);
499 auth |= CHAP_WITHPEER;
500 } else if (ho->neg_upap) {
501 if (passwd[0] == 0) {
502 passwd_from_file = 1;
503 if (!get_pap_passwd(passwd))
504 error("No secret found for PAP login");
506 upap_authwithpeer(unit, user, passwd);
507 auth |= PAP_WITHPEER;
509 auth_pending[unit] = auth;
516 * Proceed to the network phase.
522 lcp_options *go = &lcp_gotoptions[unit];
525 * If the peer had to authenticate, run the auth-up script now.
527 if (go->neg_chap || go->neg_upap) {
528 notify(auth_up_notifier, 0);
530 if (auth_script_state == s_down && auth_script_pid == 0) {
531 auth_script_state = s_up;
532 auth_script(_PATH_AUTHUP);
538 * If we negotiated callback, do it now.
541 new_phase(PHASE_CALLBACK);
542 (*cbcp_protent.open)(unit);
548 * Process extra options from the secrets file
551 options_from_list(extra_options, 1);
552 free_wordlist(extra_options);
562 struct protent *protp;
564 new_phase(PHASE_NETWORK);
566 #ifdef HAVE_MULTILINK
568 if (mp_join_bundle()) {
569 if (updetach && !nodetach)
574 #endif /* HAVE_MULTILINK */
578 set_filters(&pass_filter, &active_filter);
580 for (i = 0; (protp = protocols[i]) != NULL; ++i)
581 if (protp->protocol < 0xC000 && protp->enabled_flag
582 && protp->open != NULL) {
584 if (protp->protocol != PPP_CCP)
588 if (num_np_open == 0)
590 lcp_close(0, "No network protocols running");
594 * The peer has failed to authenticate himself using `protocol'.
597 auth_peer_fail(unit, protocol)
601 * Authentication failure: take the link down
603 lcp_close(unit, "Authentication failed");
604 status = EXIT_PEER_AUTH_FAILED;
608 * The peer has been successfully authenticated using `protocol'.
611 auth_peer_success(unit, protocol, name, namelen)
626 warn("auth_peer_success: unknown protocol %x", protocol);
631 * Save the authenticated name of the peer for later.
633 if (namelen > sizeof(peer_authname) - 1)
634 namelen = sizeof(peer_authname) - 1;
635 BCOPY(name, peer_authname, namelen);
636 peer_authname[namelen] = 0;
637 script_setenv("PEERNAME", peer_authname, 0);
640 * If there is no more authentication still to be done,
641 * proceed to the network (or callback) phase.
643 if ((auth_pending[unit] &= ~bit) == 0)
648 * We have failed to authenticate ourselves to the peer using `protocol'.
651 auth_withpeer_fail(unit, protocol)
654 if (passwd_from_file)
655 BZERO(passwd, MAXSECRETLEN);
657 * We've failed to authenticate ourselves to our peer.
658 * Some servers keep sending CHAP challenges, but there
659 * is no point in persisting without any way to get updated
660 * authentication secrets.
662 lcp_close(unit, "Failed to authenticate ourselves to peer");
663 status = EXIT_AUTH_TOPEER_FAILED;
667 * We have successfully authenticated ourselves with the peer using `protocol'.
670 auth_withpeer_success(unit, protocol)
680 if (passwd_from_file)
681 BZERO(passwd, MAXSECRETLEN);
685 warn("auth_withpeer_success: unknown protocol %x", protocol);
690 * If there is no more authentication still being done,
691 * proceed to the network (or callback) phase.
693 if ((auth_pending[unit] &= ~bit) == 0)
699 * np_up - a network protocol has come up.
707 if (num_np_up == 0) {
709 * At this point we consider that the link has come up successfully.
713 new_phase(PHASE_RUNNING);
715 if (idle_time_hook != 0)
716 tlim = (*idle_time_hook)(NULL);
718 tlim = idle_time_limit;
720 TIMEOUT(check_idle, NULL, tlim);
723 * Set a timeout to close the connection once the maximum
724 * connect time has expired.
727 TIMEOUT(connect_time_expired, 0, maxconnect);
730 * Detach now, if the updetach option was given.
732 if (updetach && !nodetach)
739 * np_down - a network protocol has gone down.
745 if (--num_np_up == 0) {
746 UNTIMEOUT(check_idle, NULL);
747 UNTIMEOUT(connect_time_expired, NULL);
748 new_phase(PHASE_NETWORK);
753 * np_finished - a network protocol has finished using the link.
756 np_finished(unit, proto)
759 if (--num_np_open <= 0) {
760 /* no further use for the link: shut up shop. */
761 lcp_close(0, "No network protocols running");
766 * check_idle - check whether the link has been idle for long
767 * enough that we can shut it down.
773 struct ppp_idle idle;
777 if (!get_idle_time(0, &idle))
779 if (idle_time_hook != 0) {
780 tlim = idle_time_hook(&idle);
782 itime = MIN(idle.xmit_idle, idle.recv_idle);
783 tlim = idle_time_limit - itime;
786 /* link is idle: shut it down. */
787 notice("Terminating connection due to lack of activity.");
788 lcp_close(0, "Link inactive");
790 status = EXIT_IDLE_TIMEOUT;
792 TIMEOUT(check_idle, NULL, tlim);
797 * connect_time_expired - log a message and close the connection.
800 connect_time_expired(arg)
803 info("Connect time expired");
804 lcp_close(0, "Connect time expired"); /* Close connection */
805 status = EXIT_CONNECT_TIME;
809 * auth_check_options - called to check authentication options.
814 lcp_options *wo = &lcp_wantoptions[0];
818 /* Default our_name to hostname, and user to our_name */
819 if (our_name[0] == 0 || usehostname)
820 strlcpy(our_name, hostname, sizeof(our_name));
822 strlcpy(user, our_name, sizeof(user));
825 * If we have a default route, require the peer to authenticate
826 * unless the noauth option was given or the real user is root.
828 if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
833 /* If authentication is required, ask peer for CHAP or PAP. */
836 if (!wo->neg_chap && !wo->neg_upap) {
846 * Check whether we have appropriate secrets to use
847 * to authenticate the peer.
850 can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
851 if (!can_auth && wo->neg_chap) {
852 can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
853 our_name, 1, &lacks_ip);
856 if (auth_required && !can_auth && noauth_addrs == NULL) {
859 "By default the remote system is required to authenticate itself");
861 "(because this system has a default route to the internet)");
862 } else if (explicit_remote)
864 "The remote system (%s) is required to authenticate itself",
868 "The remote system is required to authenticate itself");
870 "but I couldn't find any suitable secret (password) for it to use to do so.");
873 "(None of the available passwords would let it use an IP address.)");
880 * auth_reset - called when LCP is starting negotiations to recheck
881 * authentication options, i.e. whether we have appropriate secrets
882 * to use for authenticating ourselves and/or the peer.
888 lcp_options *go = &lcp_gotoptions[unit];
889 lcp_options *ao = &lcp_allowoptions[0];
891 ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
892 ao->neg_chap = !refuse_chap
894 || have_chap_secret(user, (explicit_remote? remote_name: NULL),
897 if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
900 if (!have_chap_secret((explicit_remote? remote_name: NULL),
908 * check_passwd - Check the user name and passwd against the PAP secrets
909 * file. If requested, also check against the system password database,
910 * and login the user if OK.
913 * UPAP_AUTHNAK: Authentication failed.
914 * UPAP_AUTHACK: Authentication succeeded.
915 * In either case, msg points to an appropriate message.
918 check_passwd(unit, auser, userlen, apasswd, passwdlen, msg)
929 struct wordlist *addrs = NULL, *opts = NULL;
930 char passwd[256], user[256];
931 char secret[MAXWORDLEN];
932 static int attempts = 0;
935 * Make copies of apasswd and auser, then null-terminate them.
936 * If there are unprintable characters in the password, make
939 slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
940 slprintf(user, sizeof(user), "%.*v", userlen, auser);
944 * Check if a plugin wants to handle this.
947 ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
950 set_allowed_addrs(unit, addrs, opts);
951 BZERO(passwd, sizeof(passwd));
953 free_wordlist(addrs);
957 return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
962 * Open the file of pap secrets and scan for a suitable secret
963 * for authenticating this user.
965 filename = _PATH_UPAPFILE;
968 f = fopen(filename, "r");
970 error("Can't open PAP password file %s: %m", filename);
973 check_access(f, filename);
974 if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename) < 0) {
975 warn("no PAP secret found for %s", user);
978 * If the secret is "@login", it means to check
979 * the password against the login database.
981 int login_secret = strcmp(secret, "@login") == 0;
983 if (uselogin || login_secret) {
984 /* login option or secret is @login */
985 ret = plogin(user, passwd, msg);
986 if (ret == UPAP_AUTHNAK)
987 warn("PAP login failure for %s", user);
991 if (secret[0] != 0 && !login_secret) {
992 /* password given in pap-secrets - must match */
993 if ((cryptpap || strcmp(passwd, secret) != 0)
994 && strcmp(crypt(passwd, secret), secret) != 0) {
996 warn("PAP authentication failure for %s", user);
1003 if (ret == UPAP_AUTHNAK) {
1005 *msg = "Login incorrect";
1007 * XXX can we ever get here more than once??
1008 * Frustrate passwd stealer programs.
1009 * Allow 10 tries, but start backing off after 3 (stolen from login).
1010 * On 10'th, drop the connection.
1012 if (attempts++ >= 10) {
1013 warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
1014 lcp_close(unit, "login failed");
1017 sleep((u_int) (attempts - 3) * 5);
1019 free_wordlist(opts);
1022 attempts = 0; /* Reset count */
1025 set_allowed_addrs(unit, addrs, opts);
1029 free_wordlist(addrs);
1030 BZERO(passwd, sizeof(passwd));
1031 BZERO(secret, sizeof(secret));
1037 * This function is needed for PAM.
1041 /* Static variables used to communicate between the conversation function
1042 * and the server_login function
1044 static char *PAM_username;
1045 static char *PAM_password;
1046 static int PAM_error = 0;
1047 static pam_handle_t *pamh = NULL;
1049 /* PAM conversation function
1050 * Here we assume (for now, at least) that echo on means login name, and
1051 * echo off means password.
1054 static int PAM_conv (int num_msg, const struct pam_message **msg,
1055 struct pam_response **resp, void *appdata_ptr)
1058 struct pam_response *reply = NULL;
1060 #define COPY_STRING(s) (s) ? strdup(s) : NULL
1062 reply = malloc(sizeof(struct pam_response) * num_msg);
1063 if (!reply) return PAM_CONV_ERR;
1065 for (replies = 0; replies < num_msg; replies++) {
1066 switch (msg[replies]->msg_style) {
1067 case PAM_PROMPT_ECHO_ON:
1068 reply[replies].resp_retcode = PAM_SUCCESS;
1069 reply[replies].resp = COPY_STRING(PAM_username);
1070 /* PAM frees resp */
1072 case PAM_PROMPT_ECHO_OFF:
1073 reply[replies].resp_retcode = PAM_SUCCESS;
1074 reply[replies].resp = COPY_STRING(PAM_password);
1075 /* PAM frees resp */
1080 /* ignore it, but pam still wants a NULL response... */
1081 reply[replies].resp_retcode = PAM_SUCCESS;
1082 reply[replies].resp = NULL;
1085 /* Must be an error of some sort... */
1088 return PAM_CONV_ERR;
1095 static struct pam_conv PAM_conversation = {
1099 #endif /* USE_PAM */
1102 * plogin - Check the user name and password against the system
1103 * password database, and login the user if OK.
1106 * UPAP_AUTHNAK: Login failed.
1107 * UPAP_AUTHACK: Login succeeded.
1108 * In either case, msg points to an appropriate message.
1112 plogin(user, passwd, msg)
1122 pam_error = pam_start ("ppp", user, &PAM_conversation, &pamh);
1123 if (pam_error != PAM_SUCCESS) {
1124 *msg = (char *) pam_strerror (pamh, pam_error);
1126 return UPAP_AUTHNAK;
1129 * Define the fields for the credential validation
1132 PAM_username = user;
1133 PAM_password = passwd;
1135 pam_set_item (pamh, PAM_TTY, devnam); /* this might be useful to some modules */
1140 pam_error = pam_authenticate (pamh, PAM_SILENT);
1141 if (pam_error == PAM_SUCCESS && !PAM_error) {
1142 pam_error = pam_acct_mgmt (pamh, PAM_SILENT);
1143 if (pam_error == PAM_SUCCESS)
1144 pam_error = pam_open_session (pamh, PAM_SILENT);
1147 *msg = (char *) pam_strerror (pamh, pam_error);
1152 reopen_log(); /* apparently the PAM stuff does closelog() */
1153 PAM_username = NULL;
1154 PAM_password = NULL;
1155 if (pam_error != PAM_SUCCESS)
1156 return UPAP_AUTHNAK;
1157 #else /* #ifdef USE_PAM */
1160 * Use the non-PAM methods directly
1165 struct spwd *getspnam();
1167 struct passwd *pw = getpwnam(user);
1171 return (UPAP_AUTHNAK);
1174 spwd = getspnam(user);
1177 /* check the age of the password entry */
1178 long now = time(NULL) / 86400L;
1180 if ((spwd->sp_expire > 0 && now >= spwd->sp_expire)
1181 || ((spwd->sp_max >= 0 && spwd->sp_max < 10000)
1182 && spwd->sp_lstchg >= 0
1183 && now >= spwd->sp_lstchg + spwd->sp_max)) {
1184 warn("Password for %s has expired", user);
1185 return (UPAP_AUTHNAK);
1187 pw->pw_passwd = spwd->sp_pwdp;
1192 * If no passwd, don't let them login.
1194 if (pw->pw_passwd == NULL || strlen(pw->pw_passwd) < 2
1195 || strcmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd) != 0)
1196 return (UPAP_AUTHNAK);
1198 #endif /* #ifdef USE_PAM */
1201 * Write a wtmp entry for this user.
1205 if (strncmp(tty, "/dev/", 5) == 0)
1207 logwtmp(tty, user, remote_name); /* Add wtmp login entry */
1209 #if defined(_PATH_LASTLOG) && !defined(USE_PAM)
1210 if (pw != (struct passwd *)NULL) {
1214 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
1215 (void)lseek(fd, (off_t)(pw->pw_uid * sizeof(ll)), SEEK_SET);
1216 memset((void *)&ll, 0, sizeof(ll));
1217 (void)time(&ll.ll_time);
1218 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
1219 (void)write(fd, (char *)&ll, sizeof(ll));
1223 #endif /* _PATH_LASTLOG and not USE_PAM */
1225 info("user %s logged in", user);
1228 return (UPAP_AUTHACK);
1232 * plogout - Logout the user.
1241 pam_error = pam_close_session (pamh, PAM_SILENT);
1242 pam_end (pamh, pam_error);
1245 /* Apparently the pam stuff does closelog(). */
1247 #else /* ! USE_PAM */
1251 if (strncmp(tty, "/dev/", 5) == 0)
1253 logwtmp(tty, "", ""); /* Wipe out utmp logout entry */
1254 #endif /* ! USE_PAM */
1260 * null_login - Check if a username of "" and a password of "" are
1261 * acceptable, and iff so, set the list of acceptable IP addresses
1271 struct wordlist *addrs, *opts;
1272 char secret[MAXWORDLEN];
1275 * Check if a plugin wants to handle this.
1279 ret = (*null_auth_hook)(&addrs, &opts);
1282 * Open the file of pap secrets and scan for a suitable secret.
1285 filename = _PATH_UPAPFILE;
1287 f = fopen(filename, "r");
1290 check_access(f, filename);
1292 i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename);
1293 ret = i >= 0 && secret[0] == 0;
1294 BZERO(secret, sizeof(secret));
1299 set_allowed_addrs(unit, addrs, opts);
1301 free_wordlist(opts);
1303 free_wordlist(addrs);
1310 * get_pap_passwd - get a password for authenticating ourselves with
1311 * our peer using PAP. Returns 1 on success, 0 if no suitable password
1313 * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
1316 get_pap_passwd(passwd)
1322 char secret[MAXWORDLEN];
1325 * Check whether a plugin wants to supply this.
1327 if (pap_passwd_hook) {
1328 ret = (*pap_passwd_hook)(user, passwd);
1333 filename = _PATH_UPAPFILE;
1334 f = fopen(filename, "r");
1337 check_access(f, filename);
1338 ret = scan_authfile(f, user,
1339 (remote_name[0]? remote_name: NULL),
1340 secret, NULL, NULL, filename);
1345 strlcpy(passwd, secret, MAXSECRETLEN);
1346 BZERO(secret, sizeof(secret));
1352 * have_pap_secret - check whether we have a PAP file with any
1353 * secrets that we could possibly use for authenticating the peer.
1356 have_pap_secret(lacks_ipp)
1362 struct wordlist *addrs;
1364 /* let the plugin decide, if there is one */
1365 if (pap_check_hook) {
1366 ret = (*pap_check_hook)();
1371 filename = _PATH_UPAPFILE;
1372 f = fopen(filename, "r");
1376 ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
1377 NULL, &addrs, NULL, filename);
1379 if (ret >= 0 && !some_ip_ok(addrs)) {
1385 free_wordlist(addrs);
1392 * have_chap_secret - check whether we have a CHAP file with a
1393 * secret that we could possibly use for authenticating `client'
1394 * on `server'. Either can be the null string, meaning we don't
1395 * know the identity yet.
1398 have_chap_secret(client, server, need_ip, lacks_ipp)
1407 struct wordlist *addrs;
1409 if (chap_check_hook) {
1410 ret = (*chap_check_hook)();
1416 filename = _PATH_CHAPFILE;
1417 f = fopen(filename, "r");
1421 if (client != NULL && client[0] == 0)
1423 else if (server != NULL && server[0] == 0)
1426 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename);
1428 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1434 free_wordlist(addrs);
1441 * get_secret - open the CHAP secret file and return the secret
1442 * for authenticating the given client on the given server.
1443 * (We could be either client or server).
1446 get_secret(unit, client, server, secret, secret_len, am_server)
1457 struct wordlist *addrs, *opts;
1458 char secbuf[MAXWORDLEN];
1460 if (!am_server && passwd[0] != 0) {
1461 strlcpy(secbuf, passwd, sizeof(secbuf));
1462 } else if (!am_server && chap_passwd_hook) {
1463 if ( (*chap_passwd_hook)(client, secbuf) < 0) {
1464 error("Unable to obtain CHAP password for %s on %s from plugin",
1469 filename = _PATH_CHAPFILE;
1473 f = fopen(filename, "r");
1475 error("Can't open chap secret file %s: %m", filename);
1478 check_access(f, filename);
1480 ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename);
1486 set_allowed_addrs(unit, addrs, opts);
1488 free_wordlist(opts);
1490 free_wordlist(addrs);
1493 len = strlen(secbuf);
1494 if (len > MAXSECRETLEN) {
1495 error("Secret for %s on %s is too long", client, server);
1498 BCOPY(secbuf, secret, len);
1499 BZERO(secbuf, sizeof(secbuf));
1506 * set_allowed_addrs() - set the list of allowed addresses.
1507 * Also looks for `--' indicating options to apply for this peer
1508 * and leaves the following words in extra_options.
1511 set_allowed_addrs(unit, addrs, opts)
1513 struct wordlist *addrs;
1514 struct wordlist *opts;
1517 struct wordlist *ap, **plink;
1518 struct permitted_ip *ip;
1519 char *ptr_word, *ptr_mask;
1522 u_int32_t a, mask, ah, offset;
1523 struct ipcp_options *wo = &ipcp_wantoptions[unit];
1524 u_int32_t suggested_ip = 0;
1526 if (addresses[unit] != NULL)
1527 free(addresses[unit]);
1528 addresses[unit] = NULL;
1529 if (extra_options != NULL)
1530 free_wordlist(extra_options);
1531 extra_options = opts;
1534 * Count the number of IP addresses given.
1536 n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
1539 ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
1543 /* temporarily append the noauth_addrs list to addrs */
1544 for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
1546 *plink = noauth_addrs;
1549 for (ap = addrs; ap != NULL; ap = ap->next) {
1550 /* "-" means no addresses authorized, "*" means any address allowed */
1551 ptr_word = ap->word;
1552 if (strcmp(ptr_word, "-") == 0)
1554 if (strcmp(ptr_word, "*") == 0) {
1556 ip[n].base = ip[n].mask = 0;
1562 if (*ptr_word == '!') {
1567 mask = ~ (u_int32_t) 0;
1569 ptr_mask = strchr (ptr_word, '/');
1570 if (ptr_mask != NULL) {
1574 bit_count = (int) strtol (ptr_mask+1, &endp, 10);
1575 if (bit_count <= 0 || bit_count > 32) {
1576 warn("invalid address length %v in auth. address list",
1580 bit_count = 32 - bit_count; /* # bits in host part */
1582 offset = ifunit + 1;
1586 warn("invalid address length syntax: %v", ptr_mask+1);
1593 hp = gethostbyname(ptr_word);
1594 if (hp != NULL && hp->h_addrtype == AF_INET) {
1595 a = *(u_int32_t *)hp->h_addr;
1597 np = getnetbyname (ptr_word);
1598 if (np != NULL && np->n_addrtype == AF_INET) {
1599 a = htonl (*(u_int32_t *)np->n_net);
1600 if (ptr_mask == NULL) {
1601 /* calculate appropriate mask for net */
1604 mask = IN_CLASSA_NET;
1605 else if (IN_CLASSB(ah))
1606 mask = IN_CLASSB_NET;
1607 else if (IN_CLASSC(ah))
1608 mask = IN_CLASSC_NET;
1611 a = inet_addr (ptr_word);
1615 if (ptr_mask != NULL)
1618 if (a == (u_int32_t)-1L) {
1619 warn("unknown host %s in auth. address list", ap->word);
1623 if (offset >= ~mask) {
1624 warn("interface unit %d too large for subnet %v",
1628 a = htonl((ntohl(a) & mask) + offset);
1629 mask = ~(u_int32_t)0;
1631 ip[n].mask = htonl(mask);
1632 ip[n].base = a & ip[n].mask;
1634 if (~mask == 0 && suggested_ip == 0)
1639 ip[n].permit = 0; /* make the last entry forbid all addresses */
1640 ip[n].base = 0; /* to terminate the list */
1643 addresses[unit] = ip;
1646 * If the address given for the peer isn't authorized, or if
1647 * the user hasn't given one, AND there is an authorized address
1648 * which is a single host, then use that if we find one.
1650 if (suggested_ip != 0
1651 && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) {
1652 wo->hisaddr = suggested_ip;
1654 * Do we insist on this address? No, if there are other
1655 * addresses authorized than the suggested one.
1658 wo->accept_remote = 1;
1663 * auth_ip_addr - check whether the peer is authorized to use
1664 * a given IP address. Returns 1 if authorized, 0 otherwise.
1667 auth_ip_addr(unit, addr)
1673 /* don't allow loopback or multicast address */
1674 if (bad_ip_adrs(addr))
1677 if (allowed_address_hook) {
1678 ok = allowed_address_hook(addr);
1679 if (ok >= 0) return ok;
1682 if (addresses[unit] != NULL) {
1683 ok = ip_addr_check(addr, addresses[unit]);
1689 return 0; /* no addresses authorized */
1690 return allow_any_ip || privileged || !have_route_to(addr);
1694 ip_addr_check(addr, addrs)
1696 struct permitted_ip *addrs;
1699 if ((addr & addrs->mask) == addrs->base)
1700 return addrs->permit;
1704 * bad_ip_adrs - return 1 if the IP address is one we don't want
1705 * to use, such as an address in the loopback net or a multicast address.
1706 * addr is in network byte order.
1713 return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
1714 || IN_MULTICAST(addr) || IN_BADCLASS(addr);
1718 * some_ip_ok - check a wordlist to see if it authorizes any
1723 struct wordlist *addrs;
1725 for (; addrs != 0; addrs = addrs->next) {
1726 if (addrs->word[0] == '-')
1728 if (addrs->word[0] != '!')
1729 return 1; /* some IP address is allowed */
1735 * check_access - complain if a secret file has too-liberal permissions.
1738 check_access(f, filename)
1744 if (fstat(fileno(f), &sbuf) < 0) {
1745 warn("cannot stat secret file %s: %m", filename);
1746 } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
1747 warn("Warning - secret file %s has world and/or group access",
1754 * scan_authfile - Scan an authorization file for a secret suitable
1755 * for authenticating `client' on `server'. The return value is -1
1756 * if no secret is found, otherwise >= 0. The return value has
1757 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
1758 * NONWILD_SERVER set if the secret didn't have "*" for the server.
1759 * Any following words on the line up to a "--" (i.e. address authorization
1760 * info) are placed in a wordlist and returned in *addrs. Any
1761 * following words (extra options) are placed in a wordlist and
1762 * returned in *opts.
1763 * We assume secret is NULL or points to MAXWORDLEN bytes of space.
1766 scan_authfile(f, client, server, secret, addrs, opts, filename)
1771 struct wordlist **addrs;
1772 struct wordlist **opts;
1776 int got_flag, best_flag;
1778 struct wordlist *ap, *addr_list, *alist, **app;
1779 char word[MAXWORDLEN];
1780 char atfile[MAXWORDLEN];
1781 char lsecret[MAXWORDLEN];
1788 if (!getword(f, word, &newline, filename))
1789 return -1; /* file is empty??? */
1794 * Skip until we find a word at the start of a line.
1796 while (!newline && getword(f, word, &newline, filename))
1799 break; /* got to end of file */
1802 * Got a client - check if it's a match or a wildcard.
1805 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
1810 got_flag = NONWILD_CLIENT;
1813 * Now get a server and check if it matches.
1815 if (!getword(f, word, &newline, filename))
1819 if (!ISWILD(word)) {
1820 if (server != NULL && strcmp(word, server) != 0)
1822 got_flag |= NONWILD_SERVER;
1826 * Got some sort of a match - see if it's better than what
1829 if (got_flag <= best_flag)
1835 if (!getword(f, word, &newline, filename))
1840 if (secret != NULL) {
1842 * Special syntax: @/pathname means read secret from file.
1844 if (word[0] == '@' && word[1] == '/') {
1845 strlcpy(atfile, word+1, sizeof(atfile));
1846 if ((sf = fopen(atfile, "r")) == NULL) {
1847 warn("can't open indirect secret file %s", atfile);
1850 check_access(sf, atfile);
1851 if (!getword(sf, word, &xxx, atfile)) {
1852 warn("no secret in indirect secret file %s", atfile);
1858 strlcpy(lsecret, word, sizeof(lsecret));
1862 * Now read address authorization info and make a wordlist.
1866 if (!getword(f, word, &newline, filename) || newline)
1868 ap = (struct wordlist *)
1869 malloc(sizeof(struct wordlist) + strlen(word) + 1);
1871 novm("authorized addresses");
1872 ap->word = (char *) (ap + 1);
1873 strcpy(ap->word, word);
1880 * This is the best so far; remember it.
1882 best_flag = got_flag;
1884 free_wordlist(addr_list);
1887 strlcpy(secret, lsecret, MAXWORDLEN);
1893 /* scan for a -- word indicating the start of options */
1894 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
1895 if (strcmp(ap->word, "--") == 0)
1897 /* ap = start of options */
1899 ap = ap->next; /* first option */
1900 free(*app); /* free the "--" word */
1901 *app = NULL; /* terminate addr list */
1905 else if (ap != NULL)
1909 else if (addr_list != NULL)
1910 free_wordlist(addr_list);
1916 * wordlist_count - return the number of items in a wordlist
1920 struct wordlist *wp;
1924 for (n = 0; wp != NULL; wp = wp->next)
1930 * free_wordlist - release memory allocated for a wordlist.
1934 struct wordlist *wp;
1936 struct wordlist *next;
1938 while (wp != NULL) {
1946 * auth_script_done - called when the auth-up or auth-down script
1950 auth_script_done(arg)
1953 auth_script_pid = 0;
1954 switch (auth_script_state) {
1956 if (auth_state == s_down) {
1957 auth_script_state = s_down;
1958 auth_script(_PATH_AUTHDOWN);
1962 if (auth_state == s_up) {
1963 auth_script_state = s_up;
1964 auth_script(_PATH_AUTHUP);
1971 * auth_script - execute a script with arguments
1972 * interface-name peer-name real-user tty speed
1984 if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
1985 user_name = pw->pw_name;
1987 slprintf(struid, sizeof(struid), "%d", getuid());
1990 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
1994 argv[2] = peer_authname;
1995 argv[3] = user_name;
2000 auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL);