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 1.72 2002/01/11 18:07:45 etbe 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 /* A notifier for when the peer has authenticated itself,
142 and we are proceeding to the network phase. */
143 struct notifier *auth_up_notifier = NULL;
145 /* A notifier for when the link goes down. */
146 struct notifier *link_down_notifier = NULL;
149 * This is used to ensure that we don't start an auth-up/down
150 * script while one is already running.
157 static enum script_state auth_state = s_down;
158 static enum script_state auth_script_state = s_down;
159 static pid_t auth_script_pid = 0;
161 static int used_login; /* peer authenticated against login database */
166 bool uselogin = 0; /* Use /etc/passwd for checking PAP */
167 bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */
168 bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */
169 bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */
170 bool usehostname = 0; /* Use hostname for our_name */
171 bool auth_required = 0; /* Always require authentication from peer */
172 bool allow_any_ip = 0; /* Allow peer to use any IP address */
173 bool explicit_remote = 0; /* User specified explicit remote name */
174 char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
176 static char *uafname; /* name of most recent +ua file */
178 /* Bits in auth_pending[] */
179 #define PAP_WITHPEER 1
181 #define CHAP_WITHPEER 4
184 extern char *crypt __P((const char *, const char *));
186 /* Prototypes for procedures local to this file. */
188 static void network_phase __P((int));
189 static void check_idle __P((void *));
190 static void connect_time_expired __P((void *));
191 static int plogin __P((char *, char *, char **));
192 static void plogout __P((void));
193 static int null_login __P((int));
194 static int get_pap_passwd __P((char *));
195 static int have_pap_secret __P((int *));
196 static int have_chap_secret __P((char *, char *, int, int *));
197 static int ip_addr_check __P((u_int32_t, struct permitted_ip *));
198 static int scan_authfile __P((FILE *, char *, char *, char *,
199 struct wordlist **, struct wordlist **,
201 static void free_wordlist __P((struct wordlist *));
202 static void auth_script __P((char *));
203 static void auth_script_done __P((void *));
204 static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
205 static int some_ip_ok __P((struct wordlist *));
206 static int setupapfile __P((char **));
207 static int privgroup __P((char **));
208 static int set_noauth_addr __P((char **));
209 static void check_access __P((FILE *, char *));
210 static int wordlist_count __P((struct wordlist *));
213 * Authentication-related options.
215 option_t auth_options[] = {
216 { "auth", o_bool, &auth_required,
217 "Require authentication from peer", OPT_PRIO | 1 },
218 { "noauth", o_bool, &auth_required,
219 "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
221 { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
222 "Require PAP authentication from peer",
223 OPT_PRIOSUB | 1, &auth_required },
224 { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
225 "Require PAP authentication from peer",
226 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
227 { "require-chap", o_bool, &lcp_wantoptions[0].neg_chap,
228 "Require CHAP authentication from peer",
229 OPT_PRIOSUB | 1, &auth_required },
230 { "+chap", o_bool, &lcp_wantoptions[0].neg_chap,
231 "Require CHAP authentication from peer",
232 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
234 { "refuse-pap", o_bool, &refuse_pap,
235 "Don't agree to auth to peer with PAP", 1 },
236 { "-pap", o_bool, &refuse_pap,
237 "Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
239 { "refuse-chap", o_bool, &refuse_chap,
240 "Don't agree to auth to peer with CHAP", 1 },
241 { "-chap", o_bool, &refuse_chap,
242 "Don't allow CHAP authentication with peer", OPT_ALIAS | 1 },
244 { "name", o_string, our_name,
245 "Set local name for authentication",
246 OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
248 { "+ua", o_special, (void *)setupapfile,
249 "Get PAP user and password from file",
250 OPT_PRIO | OPT_A2STRVAL, &uafname },
252 { "user", o_string, user,
253 "Set name for auth with peer", OPT_PRIO | OPT_STATIC, NULL, MAXNAMELEN },
255 { "password", o_string, passwd,
256 "Password for authenticating us to the peer",
257 OPT_PRIO | OPT_STATIC | OPT_HIDE, NULL, MAXSECRETLEN },
259 { "usehostname", o_bool, &usehostname,
260 "Must use hostname for authentication", 1 },
262 { "remotename", o_string, remote_name,
263 "Set remote name for authentication", OPT_PRIO | OPT_STATIC,
264 &explicit_remote, MAXNAMELEN },
266 { "login", o_bool, &uselogin,
267 "Use system password database for PAP", 1 },
269 { "papcrypt", o_bool, &cryptpap,
270 "PAP passwords are encrypted", 1 },
272 { "privgroup", o_special, (void *)privgroup,
273 "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
275 { "allow-ip", o_special, (void *)set_noauth_addr,
276 "Set IP address(es) which can be used without authentication",
277 OPT_PRIV | OPT_A2LIST },
283 * setupapfile - specifies UPAP info for authenticating with peer.
291 char u[MAXNAMELEN], p[MAXSECRETLEN];
294 lcp_allowoptions[0].neg_upap = 1;
296 /* open user info file */
297 fname = strdup(*argv);
299 novm("+ua file name");
301 ufile = fopen(fname, "r");
304 option_error("unable to open user login data file %s", fname);
307 check_access(ufile, fname);
311 if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
312 || fgets(p, MAXSECRETLEN - 1, ufile) == NULL){
313 option_error("unable to read user login data file %s", fname);
318 /* get rid of newlines */
320 if (l > 0 && u[l-1] == '\n')
323 if (l > 0 && p[l-1] == '\n')
326 if (override_value("user", option_priority, fname))
327 strlcpy(user, u, sizeof(user));
328 if (override_value("passwd", option_priority, fname))
329 strlcpy(passwd, p, sizeof(passwd));
336 * privgroup - allow members of the group to have privileged access.
347 option_error("group %s is unknown", *argv);
350 for (i = 0; i < ngroups; ++i) {
351 if (groups[i] == g->gr_gid) {
361 * set_noauth_addr - set address(es) that can be used without authentication.
362 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
365 set_noauth_addr(argv)
369 int l = strlen(addr) + 1;
372 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
374 novm("allow-ip argument");
375 wp->word = (char *) (wp + 1);
376 wp->next = noauth_addrs;
377 BCOPY(addr, wp->word, l);
384 * An Open on LCP has requested a change from Dead to Establish phase.
385 * Do what's necessary to bring the physical layer up.
394 * LCP has terminated the link; go to the Dead phase and take the
395 * physical layer down.
398 link_terminated(unit)
401 if (phase == PHASE_DEAD)
403 if (pap_logout_hook) {
409 new_phase(PHASE_DEAD);
410 notice("Connection terminated.");
414 * LCP has gone down; it will either die or try to re-establish.
421 struct protent *protp;
423 notify(link_down_notifier, 0);
425 if (auth_script_state == s_up && auth_script_pid == 0) {
426 update_link_stats(unit);
427 auth_script_state = s_down;
428 auth_script(_PATH_AUTHDOWN);
430 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
431 if (!protp->enabled_flag)
433 if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
434 (*protp->lowerdown)(unit);
435 if (protp->protocol < 0xC000 && protp->close != NULL)
436 (*protp->close)(unit, "LCP down");
440 if (phase != PHASE_DEAD)
441 new_phase(PHASE_ESTABLISH);
445 * The link is established.
446 * Proceed to the Dead, Authenticate or Network phase as appropriate.
449 link_established(unit)
453 lcp_options *wo = &lcp_wantoptions[unit];
454 lcp_options *go = &lcp_gotoptions[unit];
455 lcp_options *ho = &lcp_hisoptions[unit];
457 struct protent *protp;
460 * Tell higher-level protocols that LCP is up.
462 for (i = 0; (protp = protocols[i]) != NULL; ++i)
463 if (protp->protocol != PPP_LCP && protp->enabled_flag
464 && protp->lowerup != NULL)
465 (*protp->lowerup)(unit);
467 if (auth_required && !(go->neg_chap || go->neg_upap)) {
469 * We wanted the peer to authenticate itself, and it refused:
470 * if we have some address(es) it can use without auth, fine,
471 * otherwise treat it as though it authenticated with PAP using
472 * a username * of "" and a password of "". If that's not OK,
475 if (noauth_addrs != NULL) {
476 set_allowed_addrs(unit, NULL, NULL);
477 } else if (!wo->neg_upap || uselogin || !null_login(unit)) {
478 warn("peer refused to authenticate: terminating link");
479 lcp_close(unit, "peer refused to authenticate");
480 status = EXIT_PEER_AUTH_FAILED;
485 new_phase(PHASE_AUTHENTICATE);
489 ChapAuthPeer(unit, our_name, go->chap_mdtype);
491 } else if (go->neg_upap) {
496 ChapAuthWithPeer(unit, user, ho->chap_mdtype);
497 auth |= CHAP_WITHPEER;
498 } else if (ho->neg_upap) {
499 if (passwd[0] == 0) {
500 passwd_from_file = 1;
501 if (!get_pap_passwd(passwd))
502 error("No secret found for PAP login");
504 upap_authwithpeer(unit, user, passwd);
505 auth |= PAP_WITHPEER;
507 auth_pending[unit] = auth;
514 * Proceed to the network phase.
520 lcp_options *go = &lcp_gotoptions[unit];
523 * If the peer had to authenticate, run the auth-up script now.
525 if (go->neg_chap || go->neg_upap) {
526 notify(auth_up_notifier, 0);
528 if (auth_script_state == s_down && auth_script_pid == 0) {
529 auth_script_state = s_up;
530 auth_script(_PATH_AUTHUP);
536 * If we negotiated callback, do it now.
539 new_phase(PHASE_CALLBACK);
540 (*cbcp_protent.open)(unit);
546 * Process extra options from the secrets file
549 options_from_list(extra_options, 1);
550 free_wordlist(extra_options);
560 struct protent *protp;
562 new_phase(PHASE_NETWORK);
564 #ifdef HAVE_MULTILINK
566 if (mp_join_bundle()) {
567 if (updetach && !nodetach)
572 #endif /* HAVE_MULTILINK */
576 set_filters(&pass_filter, &active_filter);
578 for (i = 0; (protp = protocols[i]) != NULL; ++i)
579 if (protp->protocol < 0xC000 && protp->enabled_flag
580 && protp->open != NULL) {
582 if (protp->protocol != PPP_CCP)
586 if (num_np_open == 0)
588 lcp_close(0, "No network protocols running");
592 * The peer has failed to authenticate himself using `protocol'.
595 auth_peer_fail(unit, protocol)
599 * Authentication failure: take the link down
601 lcp_close(unit, "Authentication failed");
602 status = EXIT_PEER_AUTH_FAILED;
606 * The peer has been successfully authenticated using `protocol'.
609 auth_peer_success(unit, protocol, name, namelen)
624 warn("auth_peer_success: unknown protocol %x", protocol);
629 * Save the authenticated name of the peer for later.
631 if (namelen > sizeof(peer_authname) - 1)
632 namelen = sizeof(peer_authname) - 1;
633 BCOPY(name, peer_authname, namelen);
634 peer_authname[namelen] = 0;
635 script_setenv("PEERNAME", peer_authname, 0);
638 * If there is no more authentication still to be done,
639 * proceed to the network (or callback) phase.
641 if ((auth_pending[unit] &= ~bit) == 0)
646 * We have failed to authenticate ourselves to the peer using `protocol'.
649 auth_withpeer_fail(unit, protocol)
652 if (passwd_from_file)
653 BZERO(passwd, MAXSECRETLEN);
655 * We've failed to authenticate ourselves to our peer.
656 * Some servers keep sending CHAP challenges, but there
657 * is no point in persisting without any way to get updated
658 * authentication secrets.
660 lcp_close(unit, "Failed to authenticate ourselves to peer");
661 status = EXIT_AUTH_TOPEER_FAILED;
665 * We have successfully authenticated ourselves with the peer using `protocol'.
668 auth_withpeer_success(unit, protocol)
678 if (passwd_from_file)
679 BZERO(passwd, MAXSECRETLEN);
683 warn("auth_withpeer_success: unknown protocol %x", protocol);
688 * If there is no more authentication still being done,
689 * proceed to the network (or callback) phase.
691 if ((auth_pending[unit] &= ~bit) == 0)
697 * np_up - a network protocol has come up.
705 if (num_np_up == 0) {
707 * At this point we consider that the link has come up successfully.
711 new_phase(PHASE_RUNNING);
713 if (idle_time_hook != 0)
714 tlim = (*idle_time_hook)(NULL);
716 tlim = idle_time_limit;
718 TIMEOUT(check_idle, NULL, tlim);
721 * Set a timeout to close the connection once the maximum
722 * connect time has expired.
725 TIMEOUT(connect_time_expired, 0, maxconnect);
728 * Detach now, if the updetach option was given.
730 if (updetach && !nodetach)
737 * np_down - a network protocol has gone down.
743 if (--num_np_up == 0) {
744 UNTIMEOUT(check_idle, NULL);
745 UNTIMEOUT(connect_time_expired, NULL);
746 new_phase(PHASE_NETWORK);
751 * np_finished - a network protocol has finished using the link.
754 np_finished(unit, proto)
757 if (--num_np_open <= 0) {
758 /* no further use for the link: shut up shop. */
759 lcp_close(0, "No network protocols running");
764 * check_idle - check whether the link has been idle for long
765 * enough that we can shut it down.
771 struct ppp_idle idle;
775 if (!get_idle_time(0, &idle))
777 if (idle_time_hook != 0) {
778 tlim = idle_time_hook(&idle);
780 itime = MIN(idle.xmit_idle, idle.recv_idle);
781 tlim = idle_time_limit - itime;
784 /* link is idle: shut it down. */
785 notice("Terminating connection due to lack of activity.");
786 lcp_close(0, "Link inactive");
788 status = EXIT_IDLE_TIMEOUT;
790 TIMEOUT(check_idle, NULL, tlim);
795 * connect_time_expired - log a message and close the connection.
798 connect_time_expired(arg)
801 info("Connect time expired");
802 lcp_close(0, "Connect time expired"); /* Close connection */
803 status = EXIT_CONNECT_TIME;
807 * auth_check_options - called to check authentication options.
812 lcp_options *wo = &lcp_wantoptions[0];
816 /* Default our_name to hostname, and user to our_name */
817 if (our_name[0] == 0 || usehostname)
818 strlcpy(our_name, hostname, sizeof(our_name));
820 strlcpy(user, our_name, sizeof(user));
823 * If we have a default route, require the peer to authenticate
824 * unless the noauth option was given or the real user is root.
826 if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
831 /* If authentication is required, ask peer for CHAP or PAP. */
834 if (!wo->neg_chap && !wo->neg_upap) {
844 * Check whether we have appropriate secrets to use
845 * to authenticate the peer.
848 can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
849 if (!can_auth && wo->neg_chap) {
850 can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
851 our_name, 1, &lacks_ip);
854 if (auth_required && !can_auth && noauth_addrs == NULL) {
857 "By default the remote system is required to authenticate itself");
859 "(because this system has a default route to the internet)");
860 } else if (explicit_remote)
862 "The remote system (%s) is required to authenticate itself",
866 "The remote system is required to authenticate itself");
868 "but I couldn't find any suitable secret (password) for it to use to do so.");
871 "(None of the available passwords would let it use an IP address.)");
878 * auth_reset - called when LCP is starting negotiations to recheck
879 * authentication options, i.e. whether we have appropriate secrets
880 * to use for authenticating ourselves and/or the peer.
886 lcp_options *go = &lcp_gotoptions[unit];
887 lcp_options *ao = &lcp_allowoptions[0];
889 ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
890 ao->neg_chap = !refuse_chap
892 || have_chap_secret(user, (explicit_remote? remote_name: NULL),
895 if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
898 if (!have_chap_secret((explicit_remote? remote_name: NULL),
906 * check_passwd - Check the user name and passwd against the PAP secrets
907 * file. If requested, also check against the system password database,
908 * and login the user if OK.
911 * UPAP_AUTHNAK: Authentication failed.
912 * UPAP_AUTHACK: Authentication succeeded.
913 * In either case, msg points to an appropriate message.
916 check_passwd(unit, auser, userlen, apasswd, passwdlen, msg)
927 struct wordlist *addrs = NULL, *opts = NULL;
928 char passwd[256], user[256];
929 char secret[MAXWORDLEN];
930 static int attempts = 0;
933 * Make copies of apasswd and auser, then null-terminate them.
934 * If there are unprintable characters in the password, make
937 slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
938 slprintf(user, sizeof(user), "%.*v", userlen, auser);
942 * Check if a plugin wants to handle this.
945 ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
948 set_allowed_addrs(unit, addrs, opts);
949 BZERO(passwd, sizeof(passwd));
951 free_wordlist(addrs);
952 return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
957 * Open the file of pap secrets and scan for a suitable secret
958 * for authenticating this user.
960 filename = _PATH_UPAPFILE;
963 f = fopen(filename, "r");
965 error("Can't open PAP password file %s: %m", filename);
968 check_access(f, filename);
969 if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename) < 0) {
970 warn("no PAP secret found for %s", user);
973 * If the secret is "@login", it means to check
974 * the password against the login database.
976 int login_secret = strcmp(secret, "@login") == 0;
978 if (uselogin || login_secret) {
979 /* login option or secret is @login */
980 ret = plogin(user, passwd, msg);
981 if (ret == UPAP_AUTHNAK)
982 warn("PAP login failure for %s", user);
986 if (secret[0] != 0 && !login_secret) {
987 /* password given in pap-secrets - must match */
988 if ((cryptpap || strcmp(passwd, secret) != 0)
989 && strcmp(crypt(passwd, secret), secret) != 0) {
991 warn("PAP authentication failure for %s", user);
998 if (ret == UPAP_AUTHNAK) {
1000 *msg = "Login incorrect";
1002 * XXX can we ever get here more than once??
1003 * Frustrate passwd stealer programs.
1004 * Allow 10 tries, but start backing off after 3 (stolen from login).
1005 * On 10'th, drop the connection.
1007 if (attempts++ >= 10) {
1008 warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
1009 lcp_close(unit, "login failed");
1012 sleep((u_int) (attempts - 3) * 5);
1014 free_wordlist(opts);
1017 attempts = 0; /* Reset count */
1020 set_allowed_addrs(unit, addrs, opts);
1024 free_wordlist(addrs);
1025 BZERO(passwd, sizeof(passwd));
1026 BZERO(secret, sizeof(secret));
1032 * This function is needed for PAM.
1036 /* Static variables used to communicate between the conversation function
1037 * and the server_login function
1039 static char *PAM_username;
1040 static char *PAM_password;
1041 static int PAM_error = 0;
1042 static pam_handle_t *pamh = NULL;
1044 /* PAM conversation function
1045 * Here we assume (for now, at least) that echo on means login name, and
1046 * echo off means password.
1049 static int PAM_conv (int num_msg, const struct pam_message **msg,
1050 struct pam_response **resp, void *appdata_ptr)
1053 struct pam_response *reply = NULL;
1055 #define COPY_STRING(s) (s) ? strdup(s) : NULL
1057 reply = malloc(sizeof(struct pam_response) * num_msg);
1058 if (!reply) return PAM_CONV_ERR;
1060 for (replies = 0; replies < num_msg; replies++) {
1061 switch (msg[replies]->msg_style) {
1062 case PAM_PROMPT_ECHO_ON:
1063 reply[replies].resp_retcode = PAM_SUCCESS;
1064 reply[replies].resp = COPY_STRING(PAM_username);
1065 /* PAM frees resp */
1067 case PAM_PROMPT_ECHO_OFF:
1068 reply[replies].resp_retcode = PAM_SUCCESS;
1069 reply[replies].resp = COPY_STRING(PAM_password);
1070 /* PAM frees resp */
1075 /* ignore it, but pam still wants a NULL response... */
1076 reply[replies].resp_retcode = PAM_SUCCESS;
1077 reply[replies].resp = NULL;
1080 /* Must be an error of some sort... */
1083 return PAM_CONV_ERR;
1090 static struct pam_conv PAM_conversation = {
1094 #endif /* USE_PAM */
1097 * plogin - Check the user name and password against the system
1098 * password database, and login the user if OK.
1101 * UPAP_AUTHNAK: Login failed.
1102 * UPAP_AUTHACK: Login succeeded.
1103 * In either case, msg points to an appropriate message.
1107 plogin(user, passwd, msg)
1117 pam_error = pam_start ("ppp", user, &PAM_conversation, &pamh);
1118 if (pam_error != PAM_SUCCESS) {
1119 *msg = (char *) pam_strerror (pamh, pam_error);
1121 return UPAP_AUTHNAK;
1124 * Define the fields for the credential validation
1127 PAM_username = user;
1128 PAM_password = passwd;
1130 pam_set_item (pamh, PAM_TTY, devnam); /* this might be useful to some modules */
1135 pam_error = pam_authenticate (pamh, PAM_SILENT);
1136 if (pam_error == PAM_SUCCESS && !PAM_error) {
1137 pam_error = pam_acct_mgmt (pamh, PAM_SILENT);
1138 if (pam_error == PAM_SUCCESS)
1139 pam_error = pam_open_session (pamh, PAM_SILENT);
1142 *msg = (char *) pam_strerror (pamh, pam_error);
1147 reopen_log(); /* apparently the PAM stuff does closelog() */
1148 PAM_username = NULL;
1149 PAM_password = NULL;
1150 if (pam_error != PAM_SUCCESS)
1151 return UPAP_AUTHNAK;
1152 #else /* #ifdef USE_PAM */
1155 * Use the non-PAM methods directly
1160 struct spwd *getspnam();
1162 struct passwd *pw = getpwnam(user);
1166 return (UPAP_AUTHNAK);
1169 spwd = getspnam(user);
1172 /* check the age of the password entry */
1173 long now = time(NULL) / 86400L;
1175 if ((spwd->sp_expire > 0 && now >= spwd->sp_expire)
1176 || ((spwd->sp_max >= 0 && spwd->sp_max < 10000)
1177 && spwd->sp_lstchg >= 0
1178 && now >= spwd->sp_lstchg + spwd->sp_max)) {
1179 warn("Password for %s has expired", user);
1180 return (UPAP_AUTHNAK);
1182 pw->pw_passwd = spwd->sp_pwdp;
1187 * If no passwd, don't let them login.
1189 if (pw->pw_passwd == NULL || strlen(pw->pw_passwd) < 2
1190 || strcmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd) != 0)
1191 return (UPAP_AUTHNAK);
1193 #endif /* #ifdef USE_PAM */
1196 * Write a wtmp entry for this user.
1200 if (strncmp(tty, "/dev/", 5) == 0)
1202 logwtmp(tty, user, remote_name); /* Add wtmp login entry */
1204 #if defined(_PATH_LASTLOG) && !defined(USE_PAM)
1205 if (pw != (struct passwd *)NULL) {
1209 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
1210 (void)lseek(fd, (off_t)(pw->pw_uid * sizeof(ll)), SEEK_SET);
1211 memset((void *)&ll, 0, sizeof(ll));
1212 (void)time(&ll.ll_time);
1213 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
1214 (void)write(fd, (char *)&ll, sizeof(ll));
1218 #endif /* _PATH_LASTLOG and not USE_PAM */
1220 info("user %s logged in", user);
1223 return (UPAP_AUTHACK);
1227 * plogout - Logout the user.
1236 pam_error = pam_close_session (pamh, PAM_SILENT);
1237 pam_end (pamh, pam_error);
1240 /* Apparently the pam stuff does closelog(). */
1242 #else /* ! USE_PAM */
1246 if (strncmp(tty, "/dev/", 5) == 0)
1248 logwtmp(tty, "", ""); /* Wipe out utmp logout entry */
1249 #endif /* ! USE_PAM */
1255 * null_login - Check if a username of "" and a password of "" are
1256 * acceptable, and iff so, set the list of acceptable IP addresses
1266 struct wordlist *addrs, *opts;
1267 char secret[MAXWORDLEN];
1270 * Check if a plugin wants to handle this.
1274 ret = (*null_auth_hook)(&addrs, &opts);
1277 * Open the file of pap secrets and scan for a suitable secret.
1280 filename = _PATH_UPAPFILE;
1282 f = fopen(filename, "r");
1285 check_access(f, filename);
1287 i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename);
1288 ret = i >= 0 && secret[0] == 0;
1289 BZERO(secret, sizeof(secret));
1294 set_allowed_addrs(unit, addrs, opts);
1296 free_wordlist(opts);
1298 free_wordlist(addrs);
1305 * get_pap_passwd - get a password for authenticating ourselves with
1306 * our peer using PAP. Returns 1 on success, 0 if no suitable password
1308 * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
1311 get_pap_passwd(passwd)
1317 char secret[MAXWORDLEN];
1320 * Check whether a plugin wants to supply this.
1322 if (pap_passwd_hook) {
1323 ret = (*pap_passwd_hook)(user, passwd);
1328 filename = _PATH_UPAPFILE;
1329 f = fopen(filename, "r");
1332 check_access(f, filename);
1333 ret = scan_authfile(f, user,
1334 (remote_name[0]? remote_name: NULL),
1335 secret, NULL, NULL, filename);
1340 strlcpy(passwd, secret, MAXSECRETLEN);
1341 BZERO(secret, sizeof(secret));
1347 * have_pap_secret - check whether we have a PAP file with any
1348 * secrets that we could possibly use for authenticating the peer.
1351 have_pap_secret(lacks_ipp)
1357 struct wordlist *addrs;
1359 /* let the plugin decide, if there is one */
1360 if (pap_check_hook) {
1361 ret = (*pap_check_hook)();
1366 filename = _PATH_UPAPFILE;
1367 f = fopen(filename, "r");
1371 ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
1372 NULL, &addrs, NULL, filename);
1374 if (ret >= 0 && !some_ip_ok(addrs)) {
1380 free_wordlist(addrs);
1387 * have_chap_secret - check whether we have a CHAP file with a
1388 * secret that we could possibly use for authenticating `client'
1389 * on `server'. Either can be the null string, meaning we don't
1390 * know the identity yet.
1393 have_chap_secret(client, server, need_ip, lacks_ipp)
1402 struct wordlist *addrs;
1404 filename = _PATH_CHAPFILE;
1405 f = fopen(filename, "r");
1409 if (client != NULL && client[0] == 0)
1411 else if (server != NULL && server[0] == 0)
1414 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename);
1416 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1422 free_wordlist(addrs);
1429 * get_secret - open the CHAP secret file and return the secret
1430 * for authenticating the given client on the given server.
1431 * (We could be either client or server).
1434 get_secret(unit, client, server, secret, secret_len, am_server)
1445 struct wordlist *addrs, *opts;
1446 char secbuf[MAXWORDLEN];
1448 if (!am_server && passwd[0] != 0) {
1449 strlcpy(secbuf, passwd, sizeof(secbuf));
1451 filename = _PATH_CHAPFILE;
1455 f = fopen(filename, "r");
1457 error("Can't open chap secret file %s: %m", filename);
1460 check_access(f, filename);
1462 ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename);
1468 set_allowed_addrs(unit, addrs, opts);
1470 free_wordlist(opts);
1472 free_wordlist(addrs);
1475 len = strlen(secbuf);
1476 if (len > MAXSECRETLEN) {
1477 error("Secret for %s on %s is too long", client, server);
1480 BCOPY(secbuf, secret, len);
1481 BZERO(secbuf, sizeof(secbuf));
1488 * set_allowed_addrs() - set the list of allowed addresses.
1489 * Also looks for `--' indicating options to apply for this peer
1490 * and leaves the following words in extra_options.
1493 set_allowed_addrs(unit, addrs, opts)
1495 struct wordlist *addrs;
1496 struct wordlist *opts;
1499 struct wordlist *ap, **plink;
1500 struct permitted_ip *ip;
1501 char *ptr_word, *ptr_mask;
1504 u_int32_t a, mask, ah, offset;
1505 struct ipcp_options *wo = &ipcp_wantoptions[unit];
1506 u_int32_t suggested_ip = 0;
1508 if (addresses[unit] != NULL)
1509 free(addresses[unit]);
1510 addresses[unit] = NULL;
1511 if (extra_options != NULL)
1512 free_wordlist(extra_options);
1513 extra_options = opts;
1516 * Count the number of IP addresses given.
1518 n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
1521 ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
1525 /* temporarily append the noauth_addrs list to addrs */
1526 for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
1528 *plink = noauth_addrs;
1531 for (ap = addrs; ap != NULL; ap = ap->next) {
1532 /* "-" means no addresses authorized, "*" means any address allowed */
1533 ptr_word = ap->word;
1534 if (strcmp(ptr_word, "-") == 0)
1536 if (strcmp(ptr_word, "*") == 0) {
1538 ip[n].base = ip[n].mask = 0;
1544 if (*ptr_word == '!') {
1549 mask = ~ (u_int32_t) 0;
1551 ptr_mask = strchr (ptr_word, '/');
1552 if (ptr_mask != NULL) {
1556 bit_count = (int) strtol (ptr_mask+1, &endp, 10);
1557 if (bit_count <= 0 || bit_count > 32) {
1558 warn("invalid address length %v in auth. address list",
1562 bit_count = 32 - bit_count; /* # bits in host part */
1564 offset = ifunit + 1;
1568 warn("invalid address length syntax: %v", ptr_mask+1);
1575 hp = gethostbyname(ptr_word);
1576 if (hp != NULL && hp->h_addrtype == AF_INET) {
1577 a = *(u_int32_t *)hp->h_addr;
1579 np = getnetbyname (ptr_word);
1580 if (np != NULL && np->n_addrtype == AF_INET) {
1581 a = htonl (*(u_int32_t *)np->n_net);
1582 if (ptr_mask == NULL) {
1583 /* calculate appropriate mask for net */
1586 mask = IN_CLASSA_NET;
1587 else if (IN_CLASSB(ah))
1588 mask = IN_CLASSB_NET;
1589 else if (IN_CLASSC(ah))
1590 mask = IN_CLASSC_NET;
1593 a = inet_addr (ptr_word);
1597 if (ptr_mask != NULL)
1600 if (a == (u_int32_t)-1L) {
1601 warn("unknown host %s in auth. address list", ap->word);
1605 if (offset >= ~mask) {
1606 warn("interface unit %d too large for subnet %v",
1610 a = htonl((ntohl(a) & mask) + offset);
1611 mask = ~(u_int32_t)0;
1613 ip[n].mask = htonl(mask);
1614 ip[n].base = a & ip[n].mask;
1616 if (~mask == 0 && suggested_ip == 0)
1621 ip[n].permit = 0; /* make the last entry forbid all addresses */
1622 ip[n].base = 0; /* to terminate the list */
1625 addresses[unit] = ip;
1628 * If the address given for the peer isn't authorized, or if
1629 * the user hasn't given one, AND there is an authorized address
1630 * which is a single host, then use that if we find one.
1632 if (suggested_ip != 0
1633 && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) {
1634 wo->hisaddr = suggested_ip;
1636 * Do we insist on this address? No, if there are other
1637 * addresses authorized than the suggested one.
1640 wo->accept_remote = 1;
1645 * auth_ip_addr - check whether the peer is authorized to use
1646 * a given IP address. Returns 1 if authorized, 0 otherwise.
1649 auth_ip_addr(unit, addr)
1655 /* don't allow loopback or multicast address */
1656 if (bad_ip_adrs(addr))
1659 if (addresses[unit] != NULL) {
1660 ok = ip_addr_check(addr, addresses[unit]);
1665 return 0; /* no addresses authorized */
1666 return allow_any_ip || privileged || !have_route_to(addr);
1670 ip_addr_check(addr, addrs)
1672 struct permitted_ip *addrs;
1675 if ((addr & addrs->mask) == addrs->base)
1676 return addrs->permit;
1680 * bad_ip_adrs - return 1 if the IP address is one we don't want
1681 * to use, such as an address in the loopback net or a multicast address.
1682 * addr is in network byte order.
1689 return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
1690 || IN_MULTICAST(addr) || IN_BADCLASS(addr);
1694 * some_ip_ok - check a wordlist to see if it authorizes any
1699 struct wordlist *addrs;
1701 for (; addrs != 0; addrs = addrs->next) {
1702 if (addrs->word[0] == '-')
1704 if (addrs->word[0] != '!')
1705 return 1; /* some IP address is allowed */
1711 * check_access - complain if a secret file has too-liberal permissions.
1714 check_access(f, filename)
1720 if (fstat(fileno(f), &sbuf) < 0) {
1721 warn("cannot stat secret file %s: %m", filename);
1722 } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
1723 warn("Warning - secret file %s has world and/or group access",
1730 * scan_authfile - Scan an authorization file for a secret suitable
1731 * for authenticating `client' on `server'. The return value is -1
1732 * if no secret is found, otherwise >= 0. The return value has
1733 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
1734 * NONWILD_SERVER set if the secret didn't have "*" for the server.
1735 * Any following words on the line up to a "--" (i.e. address authorization
1736 * info) are placed in a wordlist and returned in *addrs. Any
1737 * following words (extra options) are placed in a wordlist and
1738 * returned in *opts.
1739 * We assume secret is NULL or points to MAXWORDLEN bytes of space.
1742 scan_authfile(f, client, server, secret, addrs, opts, filename)
1747 struct wordlist **addrs;
1748 struct wordlist **opts;
1752 int got_flag, best_flag;
1754 struct wordlist *ap, *addr_list, *alist, **app;
1755 char word[MAXWORDLEN];
1756 char atfile[MAXWORDLEN];
1757 char lsecret[MAXWORDLEN];
1764 if (!getword(f, word, &newline, filename))
1765 return -1; /* file is empty??? */
1770 * Skip until we find a word at the start of a line.
1772 while (!newline && getword(f, word, &newline, filename))
1775 break; /* got to end of file */
1778 * Got a client - check if it's a match or a wildcard.
1781 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
1786 got_flag = NONWILD_CLIENT;
1789 * Now get a server and check if it matches.
1791 if (!getword(f, word, &newline, filename))
1795 if (!ISWILD(word)) {
1796 if (server != NULL && strcmp(word, server) != 0)
1798 got_flag |= NONWILD_SERVER;
1802 * Got some sort of a match - see if it's better than what
1805 if (got_flag <= best_flag)
1811 if (!getword(f, word, &newline, filename))
1816 if (secret != NULL) {
1818 * Special syntax: @/pathname means read secret from file.
1820 if (word[0] == '@' && word[1] == '/') {
1821 strlcpy(atfile, word+1, sizeof(atfile));
1822 if ((sf = fopen(atfile, "r")) == NULL) {
1823 warn("can't open indirect secret file %s", atfile);
1826 check_access(sf, atfile);
1827 if (!getword(sf, word, &xxx, atfile)) {
1828 warn("no secret in indirect secret file %s", atfile);
1834 strlcpy(lsecret, word, sizeof(lsecret));
1838 * Now read address authorization info and make a wordlist.
1842 if (!getword(f, word, &newline, filename) || newline)
1844 ap = (struct wordlist *)
1845 malloc(sizeof(struct wordlist) + strlen(word) + 1);
1847 novm("authorized addresses");
1848 ap->word = (char *) (ap + 1);
1849 strcpy(ap->word, word);
1856 * This is the best so far; remember it.
1858 best_flag = got_flag;
1860 free_wordlist(addr_list);
1863 strlcpy(secret, lsecret, MAXWORDLEN);
1869 /* scan for a -- word indicating the start of options */
1870 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
1871 if (strcmp(ap->word, "--") == 0)
1873 /* ap = start of options */
1875 ap = ap->next; /* first option */
1876 free(*app); /* free the "--" word */
1877 *app = NULL; /* terminate addr list */
1881 else if (ap != NULL)
1885 else if (addr_list != NULL)
1886 free_wordlist(addr_list);
1892 * wordlist_count - return the number of items in a wordlist
1896 struct wordlist *wp;
1900 for (n = 0; wp != NULL; wp = wp->next)
1906 * free_wordlist - release memory allocated for a wordlist.
1910 struct wordlist *wp;
1912 struct wordlist *next;
1914 while (wp != NULL) {
1922 * auth_script_done - called when the auth-up or auth-down script
1926 auth_script_done(arg)
1929 auth_script_pid = 0;
1930 switch (auth_script_state) {
1932 if (auth_state == s_down) {
1933 auth_script_state = s_down;
1934 auth_script(_PATH_AUTHDOWN);
1938 if (auth_state == s_up) {
1939 auth_script_state = s_up;
1940 auth_script(_PATH_AUTHUP);
1947 * auth_script - execute a script with arguments
1948 * interface-name peer-name real-user tty speed
1960 if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
1961 user_name = pw->pw_name;
1963 slprintf(struid, sizeof(struid), "%d", getuid());
1966 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
1970 argv[2] = peer_authname;
1971 argv[3] = user_name;
1976 auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL);