1 /* $NetBSD: auth.c,v 1.5 2021/01/09 16:39:28 christos Exp $ */
2
3 /*
4 * auth.c - PPP authentication and phase control.
5 *
6 * Copyright (c) 1993-2002 Paul Mackerras. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. The name(s) of the authors of this software must not be used to
16 * endorse or promote products derived from this software without
17 * prior written permission.
18 *
19 * 3. Redistributions of any form whatsoever must retain the following
20 * acknowledgment:
21 * "This product includes software developed by Paul Mackerras
22 * <paulus@samba.org>".
23 *
24 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
25 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
26 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
27 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
28 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
29 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
30 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
31 *
32 * Derived from main.c, which is:
33 *
34 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 *
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 *
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in
45 * the documentation and/or other materials provided with the
46 * distribution.
47 *
48 * 3. The name "Carnegie Mellon University" must not be used to
49 * endorse or promote products derived from this software without
50 * prior written permission. For permission or any legal
51 * details, please contact
52 * Office of Technology Transfer
53 * Carnegie Mellon University
54 * 5000 Forbes Avenue
55 * Pittsburgh, PA 15213-3890
56 * (412) 268-4387, fax: (412) 268-7395
57 * tech-transfer@andrew.cmu.edu
58 *
59 * 4. Redistributions of any form whatsoever must retain the following
60 * acknowledgment:
61 * "This product includes software developed by Computing Services
62 * at Carnegie Mellon University (http://www.cmu.edu/computing/)."
63 *
64 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
65 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
66 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
67 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
68 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
69 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
70 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71 */
72
73 #include <sys/cdefs.h>
74 #if 0
75 #define RCSID "Id: auth.c,v 1.117 2008/07/01 12:27:56 paulus Exp "
76 static const char rcsid[] = RCSID;
77 #else
78 __RCSID("$NetBSD: auth.c,v 1.5 2021/01/09 16:39:28 christos Exp $");
79 #endif
80
81 #include <stdio.h>
82 #include <stddef.h>
83 #include <stdlib.h>
84 #include <unistd.h>
85 #include <errno.h>
86 #include <pwd.h>
87 #include <grp.h>
88 #include <string.h>
89 #include <strings.h>
90 #include <sys/types.h>
91 #include <sys/stat.h>
92 #include <sys/socket.h>
93 #include <fcntl.h>
94 #if defined(_PATH_LASTLOG) && defined(__linux__)
95 #include <lastlog.h>
96 #endif
97
98 #include <netdb.h>
99 #include <netinet/in.h>
100 #include <arpa/inet.h>
101
102
103 #ifdef HAS_SHADOW
104 #include <shadow.h>
105 #ifndef PW_PPP
106 #define PW_PPP PW_LOGIN
107 #endif
108 #endif
109 #include <time.h>
110
111 #ifdef SYSTEMD
112 #include <systemd/sd-daemon.h>
113 #endif
114
115 #include "pppd.h"
116 #include "fsm.h"
117 #include "lcp.h"
118 #include "ccp.h"
119 #include "ecp.h"
120 #include "ipcp.h"
121 #include "upap.h"
122 #include "chap-new.h"
123 #include "eap.h"
124 #ifdef USE_EAPTLS
125 #include "eap-tls.h"
126 #endif
127 #ifdef CBCP_SUPPORT
128 #include "cbcp.h"
129 #endif
130 #include "pathnames.h"
131 #include "session.h"
132
133
134 /* Bits in scan_authfile return value */
135 #define NONWILD_SERVER 1
136 #define NONWILD_CLIENT 2
137
138 #define ISWILD(word) (word[0] == '*' && word[1] == 0)
139
140 /* The name by which the peer authenticated itself to us. */
141 char peer_authname[MAXNAMELEN];
142
143 /* Records which authentication operations haven't completed yet. */
144 static int auth_pending[NUM_PPP];
145
146 /* Records which authentication operations have been completed. */
147 int auth_done[NUM_PPP];
148
149 /* List of addresses which the peer may use. */
150 static struct permitted_ip *addresses[NUM_PPP];
151
152 /* Wordlist giving addresses which the peer may use
153 without authenticating itself. */
154 static struct wordlist *noauth_addrs;
155
156 /* Remote telephone number, if available */
157 char remote_number[MAXNAMELEN];
158
159 /* Wordlist giving remote telephone numbers which may connect. */
160 static struct wordlist *permitted_numbers;
161
162 /* Extra options to apply, from the secrets file entry for the peer. */
163 static struct wordlist *extra_options;
164
165 /* Number of network protocols which we have opened. */
166 static int num_np_open;
167
168 /* Number of network protocols which have come up. */
169 static int num_np_up;
170
171 /* Set if we got the contents of passwd[] from the pap-secrets file. */
172 static int passwd_from_file;
173
174 /* Set if we require authentication only because we have a default route. */
175 static bool default_auth;
176
177 /* Hook to enable a plugin to control the idle time limit */
178 int (*idle_time_hook)(struct ppp_idle *) = NULL;
179
180 /* Hook for a plugin to say whether we can possibly authenticate any peer */
181 int (*pap_check_hook)(void) = NULL;
182
183 /* Hook for a plugin to check the PAP user and password */
184 int (*pap_auth_hook)(char *user, char *passwd, char **msgp,
185 struct wordlist **paddrs,
186 struct wordlist **popts) = NULL;
187
188 /* Hook for a plugin to know about the PAP user logout */
189 void (*pap_logout_hook)(void) = NULL;
190
191 /* Hook for a plugin to get the PAP password for authenticating us */
192 int (*pap_passwd_hook)(char *user, char *passwd) = NULL;
193
194 /* Hook for a plugin to say if we can possibly authenticate a peer using CHAP */
195 int (*chap_check_hook)(void) = NULL;
196
197 /* Hook for a plugin to get the CHAP password for authenticating us */
198 int (*chap_passwd_hook)(char *user, char *passwd) = NULL;
199
200 #ifdef USE_EAPTLS
201 /* Hook for a plugin to get the EAP-TLS password for authenticating us */
202 int (*eaptls_passwd_hook)(char *user, char *passwd) = NULL;
203 #endif
204
205 /* Hook for a plugin to say whether it is OK if the peer
206 refuses to authenticate. */
207 int (*null_auth_hook)(struct wordlist **paddrs,
208 struct wordlist **popts) = NULL;
209
210 int (*allowed_address_hook)(u_int32_t addr) = NULL;
211
212 #ifdef HAVE_MULTILINK
213 /* Hook for plugin to hear when an interface joins a multilink bundle */
214 void (*multilink_join_hook)(void) = NULL;
215 #endif
216
217 /* A notifier for when the peer has authenticated itself,
218 and we are proceeding to the network phase. */
219 struct notifier *auth_up_notifier = NULL;
220
221 /* A notifier for when the link goes down. */
222 struct notifier *link_down_notifier = NULL;
223
224 /*
225 * This is used to ensure that we don't start an auth-up/down
226 * script while one is already running.
227 */
228 enum script_state {
229 s_down,
230 s_up
231 };
232
233 static enum script_state auth_state = s_down;
234 static enum script_state auth_script_state = s_down;
235 static pid_t auth_script_pid = 0;
236
237 /*
238 * Option variables.
239 */
240 bool uselogin = 0; /* Use /etc/passwd for checking PAP */
241 bool session_mgmt = 0; /* Do session management (login records) */
242 bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */
243 bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */
244 bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */
245 bool refuse_eap = 0; /* Don't wanna auth. ourselves with EAP */
246 #ifdef CHAPMS
247 bool refuse_mschap = 0; /* Don't wanna auth. ourselves with MS-CHAP */
248 bool refuse_mschap_v2 = 0; /* Don't wanna auth. ourselves with MS-CHAPv2 */
249 #else
250 bool refuse_mschap = 1; /* Don't wanna auth. ourselves with MS-CHAP */
251 bool refuse_mschap_v2 = 1; /* Don't wanna auth. ourselves with MS-CHAPv2 */
252 #endif
253 bool usehostname = 0; /* Use hostname for our_name */
254 bool auth_required = 0; /* Always require authentication from peer */
255 bool allow_any_ip = 0; /* Allow peer to use any IP address */
256 bool explicit_remote = 0; /* User specified explicit remote name */
257 bool explicit_user = 0; /* Set if "user" option supplied */
258 bool explicit_passwd = 0; /* Set if "password" option supplied */
259 char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
260 #ifdef USE_EAPTLS
261 char *cacert_file = NULL; /* CA certificate file (pem format) */
262 char *ca_path = NULL; /* directory with CA certificates */
263 char *cert_file = NULL; /* client certificate file (pem format) */
264 char *privkey_file = NULL; /* client private key file (pem format) */
265 char *crl_dir = NULL; /* directory containing CRL files */
266 char *crl_file = NULL; /* Certificate Revocation List (CRL) file (pem format) */
267 char *max_tls_version = NULL; /* Maximum TLS protocol version (default=1.2) */
268 bool need_peer_eap = 0; /* Require peer to authenticate us */
269 #endif
270
271 static char *fname; /* name of most recent +ua file */
272
273 extern char *crypt (const char *, const char *);
274
275 /* Prototypes for procedures local to this file. */
276
277 static void network_phase (int);
278 static void check_idle (void *);
279 static void connect_time_expired (void *);
280 static int null_login (int);
281 static int get_pap_passwd (char *);
282 static int have_pap_secret (int *);
283 static int have_chap_secret (char *, char *, int, int *);
284 static int have_srp_secret(char *client, char *server, int need_ip,
285 int *lacks_ipp);
286
287 #ifdef USE_EAPTLS
288 static int have_eaptls_secret_server
289 (char *client, char *server, int need_ip, int *lacks_ipp);
290 static int have_eaptls_secret_client (char *client, char *server);
291 static int scan_authfile_eaptls(FILE * f, char *client, char *server,
292 char *cli_cert, char *serv_cert,
293 char *ca_cert, char *pk,
294 struct wordlist ** addrs,
295 struct wordlist ** opts,
296 char *filename, int flags);
297 #endif
298
299 static int ip_addr_check (u_int32_t, struct permitted_ip *);
300 static int scan_authfile(FILE *, char *, char *, char *,
301 struct wordlist **, struct wordlist **,
302 char *, int);
303 static void free_wordlist (struct wordlist *);
304 static void auth_script (char *);
305 static void auth_script_done (void *);
306 static void set_allowed_addrs (int, struct wordlist *, struct wordlist *);
307 static int some_ip_ok (struct wordlist *);
308 static int setupapfile (char **);
309 static int privgroup (char **);
310 static int set_noauth_addr (char **);
311 static int set_permitted_number (char **);
312 static void check_access (FILE *, char *);
313 static int wordlist_count (struct wordlist *);
314
315 #ifdef MAXOCTETS
316 static void check_maxoctets (void *);
317 #endif
318
319 /*
320 * Authentication-related options.
321 */
322 option_t auth_options[] = {
323 { "auth", o_bool, &auth_required,
324 "Require authentication from peer", OPT_PRIO | 1 },
325 { "noauth", o_bool, &auth_required,
326 "Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
327 &allow_any_ip },
328 { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
329 "Require PAP authentication from peer",
330 OPT_PRIOSUB | 1, &auth_required },
331 { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
332 "Require PAP authentication from peer",
333 OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
334 { "require-chap", o_bool, &auth_required,
335 "Require CHAP authentication from peer",
336 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
337 &lcp_wantoptions[0].chap_mdtype },
338 { "+chap", o_bool, &auth_required,
339 "Require CHAP authentication from peer",
340 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
341 &lcp_wantoptions[0].chap_mdtype },
342 #ifdef CHAPMS
343 { "require-mschap", o_bool, &auth_required,
344 "Require MS-CHAP authentication from peer",
345 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
346 &lcp_wantoptions[0].chap_mdtype },
347 { "+mschap", o_bool, &auth_required,
348 "Require MS-CHAP authentication from peer",
349 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
350 &lcp_wantoptions[0].chap_mdtype },
351 { "require-mschap-v2", o_bool, &auth_required,
352 "Require MS-CHAPv2 authentication from peer",
353 OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
354 &lcp_wantoptions[0].chap_mdtype },
355 { "+mschap-v2", o_bool, &auth_required,
356 "Require MS-CHAPv2 authentication from peer",
357 OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
358 &lcp_wantoptions[0].chap_mdtype },
359 #endif
360
361 { "refuse-pap", o_bool, &refuse_pap,
362 "Don't agree to auth to peer with PAP", 1 },
363 { "-pap", o_bool, &refuse_pap,
364 "Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
365 { "refuse-chap", o_bool, &refuse_chap,
366 "Don't agree to auth to peer with CHAP",
367 OPT_A2CLRB | MDTYPE_MD5,
368 &lcp_allowoptions[0].chap_mdtype },
369 { "-chap", o_bool, &refuse_chap,
370 "Don't allow CHAP authentication with peer",
371 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MD5,
372 &lcp_allowoptions[0].chap_mdtype },
373 #ifdef CHAPMS
374 { "refuse-mschap", o_bool, &refuse_mschap,
375 "Don't agree to auth to peer with MS-CHAP",
376 OPT_A2CLRB | MDTYPE_MICROSOFT,
377 &lcp_allowoptions[0].chap_mdtype },
378 { "-mschap", o_bool, &refuse_mschap,
379 "Don't allow MS-CHAP authentication with peer",
380 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT,
381 &lcp_allowoptions[0].chap_mdtype },
382 { "refuse-mschap-v2", o_bool, &refuse_mschap_v2,
383 "Don't agree to auth to peer with MS-CHAPv2",
384 OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
385 &lcp_allowoptions[0].chap_mdtype },
386 { "-mschap-v2", o_bool, &refuse_mschap_v2,
387 "Don't allow MS-CHAPv2 authentication with peer",
388 OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
389 &lcp_allowoptions[0].chap_mdtype },
390 #endif
391
392 { "require-eap", o_bool, &lcp_wantoptions[0].neg_eap,
393 "Require EAP authentication from peer", OPT_PRIOSUB | 1,
394 &auth_required },
395 { "refuse-eap", o_bool, &refuse_eap,
396 "Don't agree to authenticate to peer with EAP", 1 },
397
398 { "name", o_string, our_name,
399 "Set local name for authentication",
400 OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
401
402 { "+ua", o_special, (void *)setupapfile,
403 "Get PAP user and password from file",
404 OPT_PRIO | OPT_A2STRVAL, &fname },
405
406 { "user", o_string, user,
407 "Set name for auth with peer", OPT_PRIO | OPT_STATIC,
408 &explicit_user, MAXNAMELEN },
409
410 { "password", o_string, passwd,
411 "Password for authenticating us to the peer",
412 OPT_PRIO | OPT_STATIC | OPT_HIDE,
413 &explicit_passwd, MAXSECRETLEN },
414
415 { "usehostname", o_bool, &usehostname,
416 "Must use hostname for authentication", 1 },
417
418 { "remotename", o_string, remote_name,
419 "Set remote name for authentication", OPT_PRIO | OPT_STATIC,
420 &explicit_remote, MAXNAMELEN },
421
422 { "login", o_bool, &uselogin,
423 "Use system password database for PAP", OPT_A2COPY | 1 ,
424 &session_mgmt },
425 { "enable-session", o_bool, &session_mgmt,
426 "Enable session accounting for remote peers", OPT_PRIV | 1 },
427
428 { "papcrypt", o_bool, &cryptpap,
429 "PAP passwords are encrypted", 1 },
430
431 { "privgroup", o_special, (void *)privgroup,
432 "Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
433
434 { "allow-ip", o_special, (void *)set_noauth_addr,
435 "Set IP address(es) which can be used without authentication",
436 OPT_PRIV | OPT_A2LIST },
437
438 { "remotenumber", o_string, remote_number,
439 "Set remote telephone number for authentication", OPT_PRIO | OPT_STATIC,
440 NULL, MAXNAMELEN },
441
442 { "allow-number", o_special, (void *)set_permitted_number,
443 "Set telephone number(s) which are allowed to connect",
444 OPT_PRIV | OPT_A2LIST },
445
446 #ifdef USE_EAPTLS
447 { "ca", o_string, &cacert_file, "EAP-TLS CA certificate in PEM format" },
448 { "capath", o_string, &ca_path, "EAP-TLS CA certificate directory" },
449 { "cert", o_string, &cert_file, "EAP-TLS client certificate in PEM format" },
450 { "key", o_string, &privkey_file, "EAP-TLS client private key in PEM format" },
451 { "crl-dir", o_string, &crl_dir, "Use CRLs in directory" },
452 { "crl", o_string, &crl_file, "Use specific CRL file" },
453 { "max-tls-version", o_string, &max_tls_version,
454 "Maximum TLS version (1.0/1.1/1.2 (default)/1.3)" },
455 { "need-peer-eap", o_bool, &need_peer_eap,
456 "Require the peer to authenticate us", 1 },
457 #endif /* USE_EAPTLS */
458 { NULL }
459 };
460
461 /*
462 * setupapfile - specifies UPAP info for authenticating with peer.
463 */
464 static int
setupapfile(char ** argv)465 setupapfile(char **argv)
466 {
467 FILE *ufile;
468 int l;
469 uid_t euid;
470 char u[MAXNAMELEN], p[MAXSECRETLEN];
471
472 lcp_allowoptions[0].neg_upap = 1;
473
474 if (*argv == NULL)
475 novm("+ua file name");
476
477 if (fname != NULL)
478 free(fname);
479 /* open user info file */
480 fname = strdup(*argv);
481 if (fname == NULL)
482 novm("+ua file name");
483 euid = geteuid();
484 if (seteuid(getuid()) == -1) {
485 option_error("unable to reset uid before opening %s: %m", fname);
486 free(fname);
487 return 0;
488 }
489 ufile = fopen(fname, "r");
490 if (seteuid(euid) == -1)
491 fatal("unable to regain privileges: %m");
492 if (ufile == NULL) {
493 option_error("unable to open user login data file %s", fname);
494 free(fname);
495 return 0;
496 }
497 check_access(ufile, fname);
498
499 /* get username */
500 if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
501 || fgets(p, MAXSECRETLEN - 1, ufile) == NULL) {
502 fclose(ufile);
503 option_error("unable to read user login data file %s", fname);
504 free(fname);
505 return 0;
506 }
507 fclose(ufile);
508
509 /* get rid of newlines */
510 l = strlen(u);
511 if (l > 0 && u[l-1] == '\n')
512 u[l-1] = 0;
513 l = strlen(p);
514 if (l > 0 && p[l-1] == '\n')
515 p[l-1] = 0;
516
517 if (override_value("user", option_priority, fname)) {
518 strlcpy(user, u, sizeof(user));
519 explicit_user = 1;
520 }
521 if (override_value("passwd", option_priority, fname)) {
522 strlcpy(passwd, p, sizeof(passwd));
523 explicit_passwd = 1;
524 }
525
526 free(fname);
527 return (1);
528 }
529
530
531 /*
532 * privgroup - allow members of the group to have privileged access.
533 */
534 static int
privgroup(char ** argv)535 privgroup(char **argv)
536 {
537 struct group *g;
538 int i;
539
540 g = getgrnam(*argv);
541 if (g == 0) {
542 option_error("group %s is unknown", *argv);
543 return 0;
544 }
545 for (i = 0; i < ngroups; ++i) {
546 if (groups[i] == g->gr_gid) {
547 privileged = 1;
548 break;
549 }
550 }
551 return 1;
552 }
553
554
555 /*
556 * set_noauth_addr - set address(es) that can be used without authentication.
557 * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
558 */
559 static int
set_noauth_addr(char ** argv)560 set_noauth_addr(char **argv)
561 {
562 char *addr = *argv;
563 int l = strlen(addr) + 1;
564 struct wordlist *wp;
565
566 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
567 if (wp == NULL)
568 novm("allow-ip argument");
569 wp->word = (char *) (wp + 1);
570 wp->next = noauth_addrs;
571 BCOPY(addr, wp->word, l);
572 noauth_addrs = wp;
573 return 1;
574 }
575
576
577 /*
578 * set_permitted_number - set remote telephone number(s) that may connect.
579 */
580 static int
set_permitted_number(char ** argv)581 set_permitted_number(char **argv)
582 {
583 char *number = *argv;
584 int l = strlen(number) + 1;
585 struct wordlist *wp;
586
587 wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
588 if (wp == NULL)
589 novm("allow-number argument");
590 wp->word = (char *) (wp + 1);
591 wp->next = permitted_numbers;
592 BCOPY(number, wp->word, l);
593 permitted_numbers = wp;
594 return 1;
595 }
596
597
598 /*
599 * An Open on LCP has requested a change from Dead to Establish phase.
600 */
601 void
link_required(int unit)602 link_required(int unit)
603 {
604 }
605
606 /*
607 * Bring the link up to the point of being able to do ppp.
608 */
start_link(int unit)609 void start_link(int unit)
610 {
611 status = EXIT_CONNECT_FAILED;
612 new_phase(PHASE_SERIALCONN);
613
614 hungup = 0;
615 devfd = the_channel->connect();
616 if (devfd < 0)
617 goto fail;
618
619 /* set up the serial device as a ppp interface */
620 /*
621 * N.B. we used to do tdb_writelock/tdb_writeunlock around this
622 * (from establish_ppp to set_ifunit). However, we won't be
623 * doing the set_ifunit in multilink mode, which is the only time
624 * we need the atomicity that the tdb_writelock/tdb_writeunlock
625 * gives us. Thus we don't need the tdb_writelock/tdb_writeunlock.
626 */
627 fd_ppp = the_channel->establish_ppp(devfd);
628 if (fd_ppp < 0) {
629 status = EXIT_FATAL_ERROR;
630 goto disconnect;
631 }
632
633 if (!demand && ifunit >= 0)
634 set_ifunit(1);
635
636 /*
637 * Start opening the connection and wait for
638 * incoming events (reply, timeout, etc.).
639 */
640 if (ifunit >= 0)
641 notice("Connect: %s <--> %s", ifname, ppp_devnam);
642 else
643 notice("Starting negotiation on %s", ppp_devnam);
644 add_fd(fd_ppp);
645
646 status = EXIT_NEGOTIATION_FAILED;
647 new_phase(PHASE_ESTABLISH);
648
649 lcp_lowerup(0);
650 return;
651
652 disconnect:
653 new_phase(PHASE_DISCONNECT);
654 if (the_channel->disconnect)
655 the_channel->disconnect();
656
657 fail:
658 new_phase(PHASE_DEAD);
659 if (the_channel->cleanup)
660 (*the_channel->cleanup)();
661 }
662
663 /*
664 * LCP has terminated the link; go to the Dead phase and take the
665 * physical layer down.
666 */
667 void
link_terminated(int unit)668 link_terminated(int unit)
669 {
670 if (phase == PHASE_DEAD || phase == PHASE_MASTER)
671 return;
672 new_phase(PHASE_DISCONNECT);
673
674 if (pap_logout_hook) {
675 pap_logout_hook();
676 }
677 session_end(devnam);
678
679 if (!doing_multilink) {
680 notice("Connection terminated.");
681 print_link_stats();
682 } else
683 notice("Link terminated.");
684
685 /*
686 * Delete pid files before disestablishing ppp. Otherwise it
687 * can happen that another pppd gets the same unit and then
688 * we delete its pid file.
689 */
690 if (!doing_multilink && !demand)
691 remove_pidfiles();
692
693 /*
694 * If we may want to bring the link up again, transfer
695 * the ppp unit back to the loopback. Set the
696 * real serial device back to its normal mode of operation.
697 */
698 if (fd_ppp >= 0) {
699 remove_fd(fd_ppp);
700 clean_check();
701 the_channel->disestablish_ppp(devfd);
702 if (doing_multilink)
703 mp_exit_bundle();
704 fd_ppp = -1;
705 }
706 if (!hungup)
707 lcp_lowerdown(0);
708 if (!doing_multilink && !demand)
709 script_unsetenv("IFNAME");
710
711 /*
712 * Run disconnector script, if requested.
713 * XXX we may not be able to do this if the line has hung up!
714 */
715 if (devfd >= 0 && the_channel->disconnect) {
716 the_channel->disconnect();
717 devfd = -1;
718 }
719 if (the_channel->cleanup)
720 (*the_channel->cleanup)();
721
722 if (doing_multilink && multilink_master) {
723 if (!bundle_terminating) {
724 new_phase(PHASE_MASTER);
725 if (master_detach && !detached)
726 detach();
727 } else
728 mp_bundle_terminated();
729 } else
730 new_phase(PHASE_DEAD);
731 }
732
733 /*
734 * LCP has gone down; it will either die or try to re-establish.
735 */
736 void
link_down(int unit)737 link_down(int unit)
738 {
739 if (auth_state != s_down) {
740 notify(link_down_notifier, 0);
741 auth_state = s_down;
742 if (auth_script_state == s_up && auth_script_pid == 0) {
743 update_link_stats(unit);
744 auth_script_state = s_down;
745 auth_script(_PATH_AUTHDOWN);
746 }
747 }
748 if (!doing_multilink) {
749 upper_layers_down(unit);
750 if (phase != PHASE_DEAD && phase != PHASE_MASTER)
751 new_phase(PHASE_ESTABLISH);
752 }
753 /* XXX if doing_multilink, should do something to stop
754 network-layer traffic on the link */
755 }
756
upper_layers_down(int unit)757 void upper_layers_down(int unit)
758 {
759 int i;
760 struct protent *protp;
761
762 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
763 if (!protp->enabled_flag)
764 continue;
765 if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
766 (*protp->lowerdown)(unit);
767 if (protp->protocol < 0xC000 && protp->close != NULL)
768 (*protp->close)(unit, "LCP down");
769 }
770 num_np_open = 0;
771 num_np_up = 0;
772 }
773
774 /*
775 * The link is established.
776 * Proceed to the Dead, Authenticate or Network phase as appropriate.
777 */
778 void
link_established(int unit)779 link_established(int unit)
780 {
781 int auth;
782 lcp_options *wo = &lcp_wantoptions[unit];
783 lcp_options *go = &lcp_gotoptions[unit];
784 lcp_options *ho = &lcp_hisoptions[unit];
785 #ifdef USE_EAPTLS
786 lcp_options *ao = &lcp_allowoptions[unit];
787 #endif
788 int i;
789 struct protent *protp;
790
791 /*
792 * Tell higher-level protocols that LCP is up.
793 */
794 if (!doing_multilink) {
795 for (i = 0; (protp = protocols[i]) != NULL; ++i)
796 if (protp->protocol != PPP_LCP && protp->enabled_flag
797 && protp->lowerup != NULL)
798 (*protp->lowerup)(unit);
799 }
800
801 if (!auth_required && noauth_addrs != NULL)
802 set_allowed_addrs(unit, NULL, NULL);
803
804 if (auth_required && !(go->neg_upap || go->neg_chap || go->neg_eap)) {
805 /*
806 * We wanted the peer to authenticate itself, and it refused:
807 * if we have some address(es) it can use without auth, fine,
808 * otherwise treat it as though it authenticated with PAP using
809 * a username of "" and a password of "". If that's not OK,
810 * boot it out.
811 */
812 if (noauth_addrs != NULL) {
813 set_allowed_addrs(unit, NULL, NULL);
814 } else if (!wo->neg_upap || uselogin || !null_login(unit)) {
815 warn("peer refused to authenticate: terminating link");
816 status = EXIT_PEER_AUTH_FAILED;
817 lcp_close(unit, "peer refused to authenticate");
818 return;
819 }
820 }
821
822 #ifdef USE_EAPTLS
823 if (need_peer_eap && !ao->neg_eap) {
824 warn("eap required to authenticate us but no suitable secrets");
825 lcp_close(unit, "couldn't negotiate eap");
826 status = EXIT_AUTH_TOPEER_FAILED;
827 return;
828 }
829
830 if (need_peer_eap && !ho->neg_eap) {
831 warn("peer doesn't want to authenticate us with eap");
832 lcp_close(unit, "couldn't negotiate eap");
833 status = EXIT_PEER_AUTH_FAILED;
834 return;
835 }
836 #endif
837
838 new_phase(PHASE_AUTHENTICATE);
839 auth = 0;
840 if (go->neg_eap) {
841 eap_authpeer(unit, our_name);
842 auth |= EAP_PEER;
843 } else if (go->neg_chap) {
844 chap_auth_peer(unit, our_name, CHAP_DIGEST(go->chap_mdtype));
845 auth |= CHAP_PEER;
846 } else if (go->neg_upap) {
847 upap_authpeer(unit);
848 auth |= PAP_PEER;
849 }
850 if (ho->neg_eap) {
851 eap_authwithpeer(unit, user);
852 auth |= EAP_WITHPEER;
853 } else if (ho->neg_chap) {
854 chap_auth_with_peer(unit, user, CHAP_DIGEST(ho->chap_mdtype));
855 auth |= CHAP_WITHPEER;
856 } else if (ho->neg_upap) {
857 /* If a blank password was explicitly given as an option, trust
858 the user and don't try to look up one. */
859 if (passwd[0] == 0 && !explicit_passwd) {
860 passwd_from_file = 1;
861 if (!get_pap_passwd(passwd))
862 error("No secret found for PAP login");
863 }
864 upap_authwithpeer(unit, user, passwd);
865 auth |= PAP_WITHPEER;
866 }
867 auth_pending[unit] = auth;
868 auth_done[unit] = 0;
869
870 if (!auth)
871 network_phase(unit);
872 }
873
874 /*
875 * Proceed to the network phase.
876 */
877 static void
network_phase(int unit)878 network_phase(int unit)
879 {
880 lcp_options *go = &lcp_gotoptions[unit];
881
882 /* Log calling number. */
883 if (*remote_number)
884 notice("peer from calling number %q authorized", remote_number);
885
886 /*
887 * If the peer had to authenticate, run the auth-up script now.
888 */
889 notify(auth_up_notifier, 0);
890 if (go->neg_chap || go->neg_upap || go->neg_eap) {
891 auth_state = s_up;
892 if (auth_script_state == s_down && auth_script_pid == 0) {
893 auth_script_state = s_up;
894 auth_script(_PATH_AUTHUP);
895 }
896 }
897
898 #ifdef CBCP_SUPPORT
899 /*
900 * If we negotiated callback, do it now.
901 */
902 if (go->neg_cbcp) {
903 new_phase(PHASE_CALLBACK);
904 (*cbcp_protent.open)(unit);
905 return;
906 }
907 #endif
908
909 /*
910 * Process extra options from the secrets file
911 */
912 if (extra_options) {
913 options_from_list(extra_options, 1);
914 free_wordlist(extra_options);
915 extra_options = 0;
916 }
917 start_networks(unit);
918 }
919
920 void
start_networks(int unit)921 start_networks(int unit)
922 {
923 int i;
924 struct protent *protp;
925 int ecp_required, mppe_required;
926
927 new_phase(PHASE_NETWORK);
928
929 #ifdef HAVE_MULTILINK
930 if (multilink) {
931 if (mp_join_bundle()) {
932 if (multilink_join_hook)
933 (*multilink_join_hook)();
934 if (updetach && !nodetach)
935 detach();
936 return;
937 }
938 }
939 #endif /* HAVE_MULTILINK */
940
941 #ifdef PPP_FILTER
942 if (!demand)
943 set_filters(&pass_filter_in, &pass_filter_out,
944 &active_filter_in, &active_filter_out);
945 #endif
946 /* Start CCP and ECP */
947 for (i = 0; (protp = protocols[i]) != NULL; ++i)
948 if ((protp->protocol == PPP_ECP || protp->protocol == PPP_CCP)
949 && protp->enabled_flag && protp->open != NULL)
950 (*protp->open)(0);
951
952 /*
953 * Bring up other network protocols iff encryption is not required.
954 */
955 ecp_required = ecp_gotoptions[unit].required;
956 mppe_required = ccp_gotoptions[unit].mppe;
957 if (!ecp_required && !mppe_required)
958 continue_networks(unit);
959 }
960
961 void
continue_networks(int unit)962 continue_networks(int unit)
963 {
964 int i;
965 struct protent *protp;
966
967 /*
968 * Start the "real" network protocols.
969 */
970 for (i = 0; (protp = protocols[i]) != NULL; ++i)
971 if (protp->protocol < 0xC000
972 && protp->protocol != PPP_CCP && protp->protocol != PPP_ECP
973 && protp->enabled_flag && protp->open != NULL) {
974 (*protp->open)(0);
975 ++num_np_open;
976 }
977
978 if (num_np_open == 0)
979 /* nothing to do */
980 lcp_close(0, "No network protocols running");
981 }
982
983 /*
984 * The peer has failed to authenticate himself using `protocol'.
985 */
986 void
auth_peer_fail(int unit,int protocol)987 auth_peer_fail(int unit, int protocol)
988 {
989 /*
990 * Authentication failure: take the link down
991 */
992 status = EXIT_PEER_AUTH_FAILED;
993 lcp_close(unit, "Authentication failed");
994 }
995
996 /*
997 * The peer has been successfully authenticated using `protocol'.
998 */
999 void
auth_peer_success(int unit,int protocol,int prot_flavor,char * name,int namelen)1000 auth_peer_success(int unit, int protocol, int prot_flavor,
1001 char *name, int namelen)
1002 {
1003 int bit;
1004
1005 switch (protocol) {
1006 case PPP_CHAP:
1007 bit = CHAP_PEER;
1008 switch (prot_flavor) {
1009 case CHAP_MD5:
1010 bit |= CHAP_MD5_PEER;
1011 break;
1012 #ifdef CHAPMS
1013 case CHAP_MICROSOFT:
1014 bit |= CHAP_MS_PEER;
1015 break;
1016 case CHAP_MICROSOFT_V2:
1017 bit |= CHAP_MS2_PEER;
1018 break;
1019 #endif
1020 }
1021 break;
1022 case PPP_PAP:
1023 bit = PAP_PEER;
1024 break;
1025 case PPP_EAP:
1026 bit = EAP_PEER;
1027 break;
1028 default:
1029 warn("auth_peer_success: unknown protocol %x", protocol);
1030 return;
1031 }
1032
1033 /*
1034 * Save the authenticated name of the peer for later.
1035 */
1036 if (namelen > sizeof(peer_authname) - 1)
1037 namelen = sizeof(peer_authname) - 1;
1038 BCOPY(name, peer_authname, namelen);
1039 peer_authname[namelen] = 0;
1040 script_setenv("PEERNAME", peer_authname, 0);
1041
1042 /* Save the authentication method for later. */
1043 auth_done[unit] |= bit;
1044
1045 /*
1046 * If there is no more authentication still to be done,
1047 * proceed to the network (or callback) phase.
1048 */
1049 if ((auth_pending[unit] &= ~bit) == 0)
1050 network_phase(unit);
1051 }
1052
1053 /*
1054 * We have failed to authenticate ourselves to the peer using `protocol'.
1055 */
1056 void
auth_withpeer_fail(int unit,int protocol)1057 auth_withpeer_fail(int unit, int protocol)
1058 {
1059 if (passwd_from_file)
1060 BZERO(passwd, MAXSECRETLEN);
1061 /*
1062 * We've failed to authenticate ourselves to our peer.
1063 * Some servers keep sending CHAP challenges, but there
1064 * is no point in persisting without any way to get updated
1065 * authentication secrets.
1066 */
1067 status = EXIT_AUTH_TOPEER_FAILED;
1068 lcp_close(unit, "Failed to authenticate ourselves to peer");
1069 }
1070
1071 /*
1072 * We have successfully authenticated ourselves with the peer using `protocol'.
1073 */
1074 void
auth_withpeer_success(int unit,int protocol,int prot_flavor)1075 auth_withpeer_success(int unit, int protocol, int prot_flavor)
1076 {
1077 int bit;
1078 const char *prot = "";
1079
1080 switch (protocol) {
1081 case PPP_CHAP:
1082 bit = CHAP_WITHPEER;
1083 prot = "CHAP";
1084 switch (prot_flavor) {
1085 case CHAP_MD5:
1086 bit |= CHAP_MD5_WITHPEER;
1087 break;
1088 #ifdef CHAPMS
1089 case CHAP_MICROSOFT:
1090 bit |= CHAP_MS_WITHPEER;
1091 break;
1092 case CHAP_MICROSOFT_V2:
1093 bit |= CHAP_MS2_WITHPEER;
1094 break;
1095 #endif
1096 }
1097 break;
1098 case PPP_PAP:
1099 if (passwd_from_file)
1100 BZERO(passwd, MAXSECRETLEN);
1101 bit = PAP_WITHPEER;
1102 prot = "PAP";
1103 break;
1104 case PPP_EAP:
1105 bit = EAP_WITHPEER;
1106 prot = "EAP";
1107 break;
1108 default:
1109 warn("auth_withpeer_success: unknown protocol %x", protocol);
1110 bit = 0;
1111 }
1112
1113 notice("%s authentication succeeded", prot);
1114
1115 /* Save the authentication method for later. */
1116 auth_done[unit] |= bit;
1117
1118 /*
1119 * If there is no more authentication still being done,
1120 * proceed to the network (or callback) phase.
1121 */
1122 if ((auth_pending[unit] &= ~bit) == 0)
1123 network_phase(unit);
1124 }
1125
1126
1127 /*
1128 * np_up - a network protocol has come up.
1129 */
1130 void
np_up(int unit,int proto)1131 np_up(int unit, int proto)
1132 {
1133 int tlim;
1134
1135 if (num_np_up == 0) {
1136 /*
1137 * At this point we consider that the link has come up successfully.
1138 */
1139 status = EXIT_OK;
1140 unsuccess = 0;
1141 new_phase(PHASE_RUNNING);
1142
1143 if (idle_time_hook != 0)
1144 tlim = (*idle_time_hook)(NULL);
1145 else
1146 tlim = idle_time_limit;
1147 if (tlim > 0)
1148 TIMEOUT(check_idle, NULL, tlim);
1149
1150 /*
1151 * Set a timeout to close the connection once the maximum
1152 * connect time has expired.
1153 */
1154 if (maxconnect > 0)
1155 TIMEOUT(connect_time_expired, 0, maxconnect);
1156
1157 #ifdef MAXOCTETS
1158 if (maxoctets > 0)
1159 TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
1160 #endif
1161
1162 /*
1163 * Detach now, if the updetach option was given.
1164 */
1165 if (updetach && !nodetach) {
1166 dbglog("updetach is set. Now detaching.");
1167 detach();
1168 #ifdef SYSTEMD
1169 } else if (nodetach && up_sdnotify) {
1170 dbglog("up_sdnotify is set. Now notifying systemd: READY=1");
1171 sd_notify(0, "READY=1");
1172 #endif
1173 }
1174 }
1175 ++num_np_up;
1176 }
1177
1178 /*
1179 * np_down - a network protocol has gone down.
1180 */
1181 void
np_down(int unit,int proto)1182 np_down(int unit, int proto)
1183 {
1184 if (--num_np_up == 0) {
1185 UNTIMEOUT(check_idle, NULL);
1186 UNTIMEOUT(connect_time_expired, NULL);
1187 #ifdef MAXOCTETS
1188 UNTIMEOUT(check_maxoctets, NULL);
1189 #endif
1190 new_phase(PHASE_NETWORK);
1191 }
1192 }
1193
1194 /*
1195 * np_finished - a network protocol has finished using the link.
1196 */
1197 void
np_finished(int unit,int proto)1198 np_finished(int unit, int proto)
1199 {
1200 if (--num_np_open <= 0) {
1201 /* no further use for the link: shut up shop. */
1202 lcp_close(0, "No network protocols running");
1203 }
1204 }
1205
1206 #ifdef MAXOCTETS
1207 static void
check_maxoctets(void * arg)1208 check_maxoctets(void *arg)
1209 {
1210 unsigned int used;
1211
1212 update_link_stats(ifunit);
1213 link_stats_valid=0;
1214
1215 switch(maxoctets_dir) {
1216 case PPP_OCTETS_DIRECTION_IN:
1217 used = link_stats.bytes_in;
1218 break;
1219 case PPP_OCTETS_DIRECTION_OUT:
1220 used = link_stats.bytes_out;
1221 break;
1222 case PPP_OCTETS_DIRECTION_MAXOVERAL:
1223 case PPP_OCTETS_DIRECTION_MAXSESSION:
1224 used = (link_stats.bytes_in > link_stats.bytes_out) ? link_stats.bytes_in : link_stats.bytes_out;
1225 break;
1226 default:
1227 used = link_stats.bytes_in+link_stats.bytes_out;
1228 break;
1229 }
1230 if (used > maxoctets) {
1231 notice("Traffic limit reached. Limit: %u Used: %u", maxoctets, used);
1232 status = EXIT_TRAFFIC_LIMIT;
1233 lcp_close(0, "Traffic limit");
1234 need_holdoff = 0;
1235 } else {
1236 TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
1237 }
1238 }
1239 #endif
1240
1241 /*
1242 * check_idle - check whether the link has been idle for long
1243 * enough that we can shut it down.
1244 */
1245 static void
check_idle(void * arg)1246 check_idle(void *arg)
1247 {
1248 struct ppp_idle idle;
1249 time_t itime;
1250 int tlim;
1251
1252 if (!get_idle_time(0, &idle))
1253 return;
1254 if (idle_time_hook != 0) {
1255 tlim = idle_time_hook(&idle);
1256 } else {
1257 itime = MIN(idle.xmit_idle, idle.recv_idle);
1258 tlim = idle_time_limit - itime;
1259 }
1260 if (tlim <= 0) {
1261 /* link is idle: shut it down. */
1262 notice("Terminating connection due to lack of activity.");
1263 status = EXIT_IDLE_TIMEOUT;
1264 lcp_close(0, "Link inactive");
1265 need_holdoff = 0;
1266 } else {
1267 TIMEOUT(check_idle, NULL, tlim);
1268 }
1269 }
1270
1271 /*
1272 * connect_time_expired - log a message and close the connection.
1273 */
1274 static void
connect_time_expired(void * arg)1275 connect_time_expired(void *arg)
1276 {
1277 info("Connect time expired");
1278 status = EXIT_CONNECT_TIME;
1279 lcp_close(0, "Connect time expired"); /* Close connection */
1280 }
1281
1282 /*
1283 * auth_check_options - called to check authentication options.
1284 */
1285 void
auth_check_options(void)1286 auth_check_options(void)
1287 {
1288 lcp_options *wo = &lcp_wantoptions[0];
1289 int can_auth;
1290 int lacks_ip;
1291
1292 /* Default our_name to hostname, and user to our_name */
1293 if (our_name[0] == 0 || usehostname)
1294 strlcpy(our_name, hostname, sizeof(our_name));
1295 /* If a blank username was explicitly given as an option, trust
1296 the user and don't use our_name */
1297 if (user[0] == 0 && !explicit_user)
1298 strlcpy(user, our_name, sizeof(user));
1299
1300 /*
1301 * If we have a default route, require the peer to authenticate
1302 * unless the noauth option was given or the real user is root.
1303 */
1304 if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
1305 auth_required = 1;
1306 default_auth = 1;
1307 }
1308
1309 /* If we selected any CHAP flavors, we should probably negotiate it. :-) */
1310 if (wo->chap_mdtype)
1311 wo->neg_chap = 1;
1312
1313 /* If authentication is required, ask peer for CHAP, PAP, or EAP. */
1314 if (auth_required) {
1315 allow_any_ip = 0;
1316 if (!wo->neg_chap && !wo->neg_upap && !wo->neg_eap) {
1317 wo->neg_chap = chap_mdtype_all != MDTYPE_NONE;
1318 wo->chap_mdtype = chap_mdtype_all;
1319 wo->neg_upap = 1;
1320 wo->neg_eap = 1;
1321 }
1322 } else {
1323 wo->neg_chap = 0;
1324 wo->chap_mdtype = MDTYPE_NONE;
1325 wo->neg_upap = 0;
1326 wo->neg_eap = 0;
1327 }
1328
1329 /*
1330 * Check whether we have appropriate secrets to use
1331 * to authenticate the peer. Note that EAP can authenticate by way
1332 * of a CHAP-like exchanges as well as SRP.
1333 */
1334 lacks_ip = 0;
1335 can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
1336 if (!can_auth && (wo->neg_chap || wo->neg_eap)) {
1337 can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
1338 our_name, 1, &lacks_ip);
1339 }
1340 if (!can_auth && wo->neg_eap) {
1341 can_auth = have_srp_secret((explicit_remote? remote_name: NULL),
1342 our_name, 1, &lacks_ip);
1343 }
1344
1345 #ifdef USE_EAPTLS
1346 if (!can_auth && wo->neg_eap) {
1347 can_auth =
1348 have_eaptls_secret_server((explicit_remote ? remote_name :
1349 NULL), our_name, 1, &lacks_ip);
1350
1351 }
1352 #endif
1353
1354 if (auth_required && !can_auth && noauth_addrs == NULL) {
1355 if (default_auth) {
1356 option_error(
1357 "By default the remote system is required to authenticate itself");
1358 option_error(
1359 "(because this system has a default route to the internet)");
1360 } else if (explicit_remote)
1361 option_error(
1362 "The remote system (%s) is required to authenticate itself",
1363 remote_name);
1364 else
1365 option_error(
1366 "The remote system is required to authenticate itself");
1367 option_error(
1368 "but I couldn't find any suitable secret (password) for it to use to do so.");
1369 if (lacks_ip)
1370 option_error(
1371 "(None of the available passwords would let it use an IP address.)");
1372
1373 exit(1);
1374 }
1375
1376 /*
1377 * Early check for remote number authorization.
1378 */
1379 if (!auth_number()) {
1380 warn("calling number %q is not authorized", remote_number);
1381 exit(EXIT_CNID_AUTH_FAILED);
1382 }
1383 }
1384
1385 /*
1386 * auth_reset - called when LCP is starting negotiations to recheck
1387 * authentication options, i.e. whether we have appropriate secrets
1388 * to use for authenticating ourselves and/or the peer.
1389 */
1390 void
auth_reset(int unit)1391 auth_reset(int unit)
1392 {
1393 lcp_options *go = &lcp_gotoptions[unit];
1394 lcp_options *ao = &lcp_allowoptions[unit];
1395 int hadchap;
1396
1397 hadchap = -1;
1398 ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
1399 ao->neg_chap = (!refuse_chap || !refuse_mschap || !refuse_mschap_v2)
1400 && ((passwd[0] != 0 || explicit_passwd) ||
1401 (hadchap = have_chap_secret(user, (explicit_remote? remote_name:
1402 NULL), 0, NULL)));
1403 ao->neg_eap = !refuse_eap && (
1404 passwd[0] != 0 ||
1405 (hadchap == 1 || (hadchap == -1 && have_chap_secret(user,
1406 (explicit_remote? remote_name: NULL), 0, NULL))) ||
1407 have_srp_secret(user, (explicit_remote? remote_name: NULL), 0, NULL)
1408 #ifdef USE_EAPTLS
1409 || have_eaptls_secret_client(user, (explicit_remote? remote_name: NULL))
1410 #endif
1411 );
1412
1413 hadchap = -1;
1414 if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
1415 go->neg_upap = 0;
1416 if (go->neg_chap) {
1417 if (!(hadchap = have_chap_secret((explicit_remote? remote_name: NULL),
1418 our_name, 1, NULL)))
1419 go->neg_chap = 0;
1420 }
1421 if (go->neg_eap &&
1422 (hadchap == 0 || (hadchap == -1 &&
1423 !have_chap_secret((explicit_remote? remote_name: NULL), our_name,
1424 1, NULL))) &&
1425 !have_srp_secret((explicit_remote? remote_name: NULL), our_name, 1,
1426 NULL)
1427 #ifdef USE_EAPTLS
1428 && !have_eaptls_secret_server((explicit_remote? remote_name: NULL),
1429 our_name, 1, NULL)
1430 #endif
1431 )
1432 go->neg_eap = 0;
1433 }
1434
1435
1436 /*
1437 * check_passwd - Check the user name and passwd against the PAP secrets
1438 * file. If requested, also check against the system password database,
1439 * and login the user if OK.
1440 *
1441 * returns:
1442 * UPAP_AUTHNAK: Authentication failed.
1443 * UPAP_AUTHACK: Authentication succeeded.
1444 * In either case, msg points to an appropriate message.
1445 */
1446 int
check_passwd(int unit,char * auser,int userlen,char * apasswd,int passwdlen,char ** msg)1447 check_passwd(int unit,
1448 char *auser, int userlen,
1449 char *apasswd, int passwdlen, char **msg)
1450 {
1451 int ret;
1452 char *filename;
1453 FILE *f;
1454 struct wordlist *addrs = NULL, *opts = NULL;
1455 char passwd[256], user[256];
1456 char secret[MAXWORDLEN];
1457 static int attempts = 0;
1458
1459 /*
1460 * Make copies of apasswd and auser, then null-terminate them.
1461 * If there are unprintable characters in the password, make
1462 * them visible.
1463 */
1464 slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
1465 slprintf(user, sizeof(user), "%.*v", userlen, auser);
1466 *msg = "";
1467
1468 /*
1469 * Check if a plugin wants to handle this.
1470 */
1471 if (pap_auth_hook) {
1472 ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
1473 if (ret >= 0) {
1474 /* note: set_allowed_addrs() saves opts (but not addrs):
1475 don't free it! */
1476 if (ret)
1477 set_allowed_addrs(unit, addrs, opts);
1478 else if (opts != 0)
1479 free_wordlist(opts);
1480 if (addrs != 0)
1481 free_wordlist(addrs);
1482 BZERO(passwd, sizeof(passwd));
1483 return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
1484 }
1485 }
1486
1487 /*
1488 * Open the file of pap secrets and scan for a suitable secret
1489 * for authenticating this user.
1490 */
1491 filename = _PATH_UPAPFILE;
1492 addrs = opts = NULL;
1493 ret = UPAP_AUTHNAK;
1494 f = fopen(filename, "r");
1495 if (f == NULL) {
1496 error("Can't open PAP password file %s: %m", filename);
1497
1498 } else {
1499 check_access(f, filename);
1500 if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename, 0) < 0) {
1501 warn("no PAP secret found for %s", user);
1502 } else {
1503 /*
1504 * If the secret is "@login", it means to check
1505 * the password against the login database.
1506 */
1507 int login_secret = strcmp(secret, "@login") == 0;
1508 ret = UPAP_AUTHACK;
1509 if (uselogin || login_secret) {
1510 /* login option or secret is @login */
1511 if (session_full(user, passwd, devnam, msg) == 0) {
1512 ret = UPAP_AUTHNAK;
1513 }
1514 } else if (session_mgmt) {
1515 if (session_check(user, NULL, devnam, NULL) == 0) {
1516 warn("Peer %q failed PAP Session verification", user);
1517 ret = UPAP_AUTHNAK;
1518 }
1519 }
1520 if (secret[0] != 0 && !login_secret) {
1521 /* password given in pap-secrets - must match */
1522 if (cryptpap || strcmp(passwd, secret) != 0) {
1523 char *cbuf = crypt(passwd, secret);
1524 if (!cbuf || strcmp(cbuf, secret) != 0)
1525 ret = UPAP_AUTHNAK;
1526 }
1527 }
1528 }
1529 fclose(f);
1530 }
1531
1532 if (ret == UPAP_AUTHNAK) {
1533 if (**msg == 0)
1534 *msg = "Login incorrect";
1535 /*
1536 * XXX can we ever get here more than once??
1537 * Frustrate passwd stealer programs.
1538 * Allow 10 tries, but start backing off after 3 (stolen from login).
1539 * On 10'th, drop the connection.
1540 */
1541 if (attempts++ >= 10) {
1542 warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
1543 lcp_close(unit, "login failed");
1544 }
1545 if (attempts > 3)
1546 sleep((u_int) (attempts - 3) * 5);
1547 if (opts != NULL)
1548 free_wordlist(opts);
1549
1550 } else {
1551 attempts = 0; /* Reset count */
1552 if (**msg == 0)
1553 *msg = "Login ok";
1554 set_allowed_addrs(unit, addrs, opts);
1555 }
1556
1557 if (addrs != NULL)
1558 free_wordlist(addrs);
1559 BZERO(passwd, sizeof(passwd));
1560 BZERO(secret, sizeof(secret));
1561
1562 return ret;
1563 }
1564
1565 /*
1566 * null_login - Check if a username of "" and a password of "" are
1567 * acceptable, and iff so, set the list of acceptable IP addresses
1568 * and return 1.
1569 */
1570 static int
null_login(int unit)1571 null_login(int unit)
1572 {
1573 char *filename;
1574 FILE *f;
1575 int i, ret;
1576 struct wordlist *addrs, *opts;
1577 char secret[MAXWORDLEN];
1578
1579 /*
1580 * Check if a plugin wants to handle this.
1581 */
1582 ret = -1;
1583 if (null_auth_hook)
1584 ret = (*null_auth_hook)(&addrs, &opts);
1585
1586 /*
1587 * Open the file of pap secrets and scan for a suitable secret.
1588 */
1589 if (ret <= 0) {
1590 filename = _PATH_UPAPFILE;
1591 addrs = NULL;
1592 f = fopen(filename, "r");
1593 if (f == NULL)
1594 return 0;
1595 check_access(f, filename);
1596
1597 i = scan_authfile(f, "", our_name, secret, &addrs, &opts, filename, 0);
1598 ret = i >= 0 && secret[0] == 0;
1599 BZERO(secret, sizeof(secret));
1600 fclose(f);
1601 }
1602
1603 if (ret)
1604 set_allowed_addrs(unit, addrs, opts);
1605 else if (opts != 0)
1606 free_wordlist(opts);
1607 if (addrs != 0)
1608 free_wordlist(addrs);
1609
1610 return ret;
1611 }
1612
1613
1614 /*
1615 * get_pap_passwd - get a password for authenticating ourselves with
1616 * our peer using PAP. Returns 1 on success, 0 if no suitable password
1617 * could be found.
1618 * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
1619 */
1620 static int
get_pap_passwd(char * passwd)1621 get_pap_passwd(char *passwd)
1622 {
1623 char *filename;
1624 FILE *f;
1625 int ret;
1626 char secret[MAXWORDLEN];
1627
1628 /*
1629 * Check whether a plugin wants to supply this.
1630 */
1631 if (pap_passwd_hook) {
1632 ret = (*pap_passwd_hook)(user, passwd);
1633 if (ret >= 0)
1634 return ret;
1635 }
1636
1637 filename = _PATH_UPAPFILE;
1638 f = fopen(filename, "r");
1639 if (f == NULL)
1640 return 0;
1641 check_access(f, filename);
1642 ret = scan_authfile(f, user,
1643 (remote_name[0]? remote_name: NULL),
1644 secret, NULL, NULL, filename, 0);
1645 fclose(f);
1646 if (ret < 0)
1647 return 0;
1648 if (passwd != NULL)
1649 strlcpy(passwd, secret, MAXSECRETLEN);
1650 BZERO(secret, sizeof(secret));
1651 return 1;
1652 }
1653
1654
1655 /*
1656 * have_pap_secret - check whether we have a PAP file with any
1657 * secrets that we could possibly use for authenticating the peer.
1658 */
1659 static int
have_pap_secret(int * lacks_ipp)1660 have_pap_secret(int *lacks_ipp)
1661 {
1662 FILE *f;
1663 int ret;
1664 char *filename;
1665 struct wordlist *addrs;
1666
1667 /* let the plugin decide, if there is one */
1668 if (pap_check_hook) {
1669 ret = (*pap_check_hook)();
1670 if (ret >= 0)
1671 return ret;
1672 }
1673
1674 filename = _PATH_UPAPFILE;
1675 f = fopen(filename, "r");
1676 if (f == NULL)
1677 return 0;
1678
1679 ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
1680 NULL, &addrs, NULL, filename, 0);
1681 fclose(f);
1682 if (ret >= 0 && !some_ip_ok(addrs)) {
1683 if (lacks_ipp != 0)
1684 *lacks_ipp = 1;
1685 ret = -1;
1686 }
1687 if (addrs != 0)
1688 free_wordlist(addrs);
1689
1690 return ret >= 0;
1691 }
1692
1693
1694 /*
1695 * have_chap_secret - check whether we have a CHAP file with a
1696 * secret that we could possibly use for authenticating `client'
1697 * on `server'. Either can be the null string, meaning we don't
1698 * know the identity yet.
1699 */
1700 static int
have_chap_secret(char * client,char * server,int need_ip,int * lacks_ipp)1701 have_chap_secret(char *client, char *server,
1702 int need_ip, int *lacks_ipp)
1703 {
1704 FILE *f;
1705 int ret;
1706 char *filename;
1707 struct wordlist *addrs;
1708
1709 if (chap_check_hook) {
1710 ret = (*chap_check_hook)();
1711 if (ret >= 0) {
1712 return ret;
1713 }
1714 }
1715
1716 filename = _PATH_CHAPFILE;
1717 f = fopen(filename, "r");
1718 if (f == NULL)
1719 return 0;
1720
1721 if (client != NULL && client[0] == 0)
1722 client = NULL;
1723 else if (server != NULL && server[0] == 0)
1724 server = NULL;
1725
1726 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
1727 fclose(f);
1728 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1729 if (lacks_ipp != 0)
1730 *lacks_ipp = 1;
1731 ret = -1;
1732 }
1733 if (addrs != 0)
1734 free_wordlist(addrs);
1735
1736 return ret >= 0;
1737 }
1738
1739
1740 /*
1741 * have_srp_secret - check whether we have a SRP file with a
1742 * secret that we could possibly use for authenticating `client'
1743 * on `server'. Either can be the null string, meaning we don't
1744 * know the identity yet.
1745 */
1746 static int
have_srp_secret(char * client,char * server,int need_ip,int * lacks_ipp)1747 have_srp_secret(char *client, char *server, int need_ip, int *lacks_ipp)
1748 {
1749 FILE *f;
1750 int ret;
1751 char *filename;
1752 struct wordlist *addrs;
1753
1754 filename = _PATH_SRPFILE;
1755 f = fopen(filename, "r");
1756 if (f == NULL)
1757 return 0;
1758
1759 if (client != NULL && client[0] == 0)
1760 client = NULL;
1761 else if (server != NULL && server[0] == 0)
1762 server = NULL;
1763
1764 ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
1765 fclose(f);
1766 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
1767 if (lacks_ipp != 0)
1768 *lacks_ipp = 1;
1769 ret = -1;
1770 }
1771 if (addrs != 0)
1772 free_wordlist(addrs);
1773
1774 return ret >= 0;
1775 }
1776
1777
1778 /*
1779 * get_secret - open the CHAP secret file and return the secret
1780 * for authenticating the given client on the given server.
1781 * (We could be either client or server).
1782 */
1783 int
get_secret(int unit,char * client,char * server,char * secret,int * secret_len,int am_server)1784 get_secret(int unit, char *client, char *server,
1785 char *secret, int *secret_len, int am_server)
1786 {
1787 FILE *f;
1788 int ret, len;
1789 char *filename;
1790 struct wordlist *addrs, *opts;
1791 char secbuf[MAXWORDLEN];
1792
1793 if (!am_server && passwd[0] != 0) {
1794 strlcpy(secbuf, passwd, sizeof(secbuf));
1795 } else if (!am_server && chap_passwd_hook) {
1796 if ( (*chap_passwd_hook)(client, secbuf) < 0) {
1797 error("Unable to obtain CHAP password for %s on %s from plugin",
1798 client, server);
1799 return 0;
1800 }
1801 } else {
1802 filename = _PATH_CHAPFILE;
1803 addrs = NULL;
1804 secbuf[0] = 0;
1805
1806 f = fopen(filename, "r");
1807 if (f == NULL) {
1808 error("Can't open chap secret file %s: %m", filename);
1809 return 0;
1810 }
1811 check_access(f, filename);
1812
1813 ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename, 0);
1814 fclose(f);
1815 if (ret < 0)
1816 return 0;
1817
1818 if (am_server)
1819 set_allowed_addrs(unit, addrs, opts);
1820 else if (opts != 0)
1821 free_wordlist(opts);
1822 if (addrs != 0)
1823 free_wordlist(addrs);
1824 }
1825
1826 len = strlen(secbuf);
1827 if (len > MAXSECRETLEN) {
1828 error("Secret for %s on %s is too long", client, server);
1829 len = MAXSECRETLEN;
1830 }
1831 BCOPY(secbuf, secret, len);
1832 BZERO(secbuf, sizeof(secbuf));
1833 *secret_len = len;
1834
1835 return 1;
1836 }
1837
1838
1839 /*
1840 * get_srp_secret - open the SRP secret file and return the secret
1841 * for authenticating the given client on the given server.
1842 * (We could be either client or server).
1843 */
1844 int
get_srp_secret(int unit,char * client,char * server,char * secret,int am_server)1845 get_srp_secret(int unit, char *client, char *server,
1846 char *secret, int am_server)
1847 {
1848 FILE *fp;
1849 int ret;
1850 char *filename;
1851 struct wordlist *addrs, *opts;
1852
1853 if (!am_server && passwd[0] != '\0') {
1854 strlcpy(secret, passwd, MAXWORDLEN);
1855 } else {
1856 filename = _PATH_SRPFILE;
1857 addrs = NULL;
1858
1859 fp = fopen(filename, "r");
1860 if (fp == NULL) {
1861 error("Can't open srp secret file %s: %m", filename);
1862 return 0;
1863 }
1864 check_access(fp, filename);
1865
1866 secret[0] = '\0';
1867 ret = scan_authfile(fp, client, server, secret, &addrs, &opts,
1868 filename, am_server);
1869 fclose(fp);
1870 if (ret < 0)
1871 return 0;
1872
1873 if (am_server)
1874 set_allowed_addrs(unit, addrs, opts);
1875 else if (opts != NULL)
1876 free_wordlist(opts);
1877 if (addrs != NULL)
1878 free_wordlist(addrs);
1879 }
1880
1881 return 1;
1882 }
1883
1884 /*
1885 * set_allowed_addrs() - set the list of allowed addresses.
1886 * Also looks for `--' indicating options to apply for this peer
1887 * and leaves the following words in extra_options.
1888 */
1889 static void
set_allowed_addrs(int unit,struct wordlist * addrs,struct wordlist * opts)1890 set_allowed_addrs(int unit, struct wordlist *addrs,
1891 struct wordlist *opts)
1892 {
1893 int n;
1894 struct wordlist *ap, **plink;
1895 struct permitted_ip *ip;
1896 char *ptr_word, *ptr_mask;
1897 struct hostent *hp;
1898 struct netent *np;
1899 u_int32_t a, mask, ah, offset;
1900 struct ipcp_options *wo = &ipcp_wantoptions[unit];
1901 u_int32_t suggested_ip = 0;
1902
1903 if (addresses[unit] != NULL)
1904 free(addresses[unit]);
1905 addresses[unit] = NULL;
1906 if (extra_options != NULL)
1907 free_wordlist(extra_options);
1908 extra_options = opts;
1909
1910 /*
1911 * Count the number of IP addresses given.
1912 */
1913 n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
1914 if (n == 0)
1915 return;
1916 ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
1917 if (ip == 0)
1918 return;
1919
1920 /* temporarily append the noauth_addrs list to addrs */
1921 for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
1922 ;
1923 *plink = noauth_addrs;
1924
1925 n = 0;
1926 for (ap = addrs; ap != NULL; ap = ap->next) {
1927 /* "-" means no addresses authorized, "*" means any address allowed */
1928 ptr_word = ap->word;
1929 if (strcmp(ptr_word, "-") == 0)
1930 break;
1931 if (strcmp(ptr_word, "*") == 0) {
1932 ip[n].permit = 1;
1933 ip[n].base = ip[n].mask = 0;
1934 ++n;
1935 break;
1936 }
1937
1938 ip[n].permit = 1;
1939 if (*ptr_word == '!') {
1940 ip[n].permit = 0;
1941 ++ptr_word;
1942 }
1943
1944 mask = ~ (u_int32_t) 0;
1945 offset = 0;
1946 ptr_mask = strchr (ptr_word, '/');
1947 if (ptr_mask != NULL) {
1948 int bit_count;
1949 char *endp;
1950
1951 bit_count = (int) strtol (ptr_mask+1, &endp, 10);
1952 if (bit_count <= 0 || bit_count > 32) {
1953 warn("invalid address length %v in auth. address list",
1954 ptr_mask+1);
1955 continue;
1956 }
1957 bit_count = 32 - bit_count; /* # bits in host part */
1958 if (*endp == '+') {
1959 offset = ifunit + 1;
1960 ++endp;
1961 }
1962 if (*endp != 0) {
1963 warn("invalid address length syntax: %v", ptr_mask+1);
1964 continue;
1965 }
1966 *ptr_mask = '\0';
1967 mask <<= bit_count;
1968 }
1969
1970 hp = gethostbyname(ptr_word);
1971 if (hp != NULL && hp->h_addrtype == AF_INET) {
1972 a = *(u_int32_t *)hp->h_addr;
1973 } else {
1974 np = getnetbyname (ptr_word);
1975 if (np != NULL && np->n_addrtype == AF_INET) {
1976 a = htonl ((u_int32_t)np->n_net);
1977 if (ptr_mask == NULL) {
1978 /* calculate appropriate mask for net */
1979 ah = ntohl(a);
1980 if (IN_CLASSA(ah))
1981 mask = IN_CLASSA_NET;
1982 else if (IN_CLASSB(ah))
1983 mask = IN_CLASSB_NET;
1984 else if (IN_CLASSC(ah))
1985 mask = IN_CLASSC_NET;
1986 }
1987 } else {
1988 a = inet_addr (ptr_word);
1989 }
1990 }
1991
1992 if (ptr_mask != NULL)
1993 *ptr_mask = '/';
1994
1995 if (a == (u_int32_t)-1L) {
1996 warn("unknown host %s in auth. address list", ap->word);
1997 continue;
1998 }
1999 if (offset != 0) {
2000 if (offset >= ~mask) {
2001 warn("interface unit %d too large for subnet %v",
2002 ifunit, ptr_word);
2003 continue;
2004 }
2005 a = htonl((ntohl(a) & mask) + offset);
2006 mask = ~(u_int32_t)0;
2007 }
2008 ip[n].mask = htonl(mask);
2009 ip[n].base = a & ip[n].mask;
2010 ++n;
2011 if (~mask == 0 && suggested_ip == 0)
2012 suggested_ip = a;
2013 }
2014 *plink = NULL;
2015
2016 ip[n].permit = 0; /* make the last entry forbid all addresses */
2017 ip[n].base = 0; /* to terminate the list */
2018 ip[n].mask = 0;
2019
2020 addresses[unit] = ip;
2021
2022 /*
2023 * If the address given for the peer isn't authorized, or if
2024 * the user hasn't given one, AND there is an authorized address
2025 * which is a single host, then use that if we find one.
2026 */
2027 if (suggested_ip != 0
2028 && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) {
2029 wo->hisaddr = suggested_ip;
2030 /*
2031 * Do we insist on this address? No, if there are other
2032 * addresses authorized than the suggested one.
2033 */
2034 if (n > 1)
2035 wo->accept_remote = 1;
2036 }
2037 }
2038
2039 /*
2040 * auth_ip_addr - check whether the peer is authorized to use
2041 * a given IP address. Returns 1 if authorized, 0 otherwise.
2042 */
2043 int
auth_ip_addr(int unit,u_int32_t addr)2044 auth_ip_addr(int unit, u_int32_t addr)
2045 {
2046 int ok;
2047
2048 /* don't allow loopback or multicast address */
2049 if (bad_ip_adrs(addr))
2050 return 0;
2051
2052 if (allowed_address_hook) {
2053 ok = allowed_address_hook(addr);
2054 if (ok >= 0) return ok;
2055 }
2056
2057 if (addresses[unit] != NULL) {
2058 ok = ip_addr_check(addr, addresses[unit]);
2059 if (ok >= 0)
2060 return ok;
2061 }
2062
2063 if (auth_required)
2064 return 0; /* no addresses authorized */
2065 return allow_any_ip || privileged || !have_route_to(addr);
2066 }
2067
2068 static int
ip_addr_check(u_int32_t addr,struct permitted_ip * addrs)2069 ip_addr_check(u_int32_t addr, struct permitted_ip *addrs)
2070 {
2071 for (; ; ++addrs)
2072 if ((addr & addrs->mask) == addrs->base)
2073 return addrs->permit;
2074 }
2075
2076 /*
2077 * bad_ip_adrs - return 1 if the IP address is one we don't want
2078 * to use, such as an address in the loopback net or a multicast address.
2079 * addr is in network byte order.
2080 */
2081 int
bad_ip_adrs(u_int32_t addr)2082 bad_ip_adrs(u_int32_t addr)
2083 {
2084 addr = ntohl(addr);
2085 return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
2086 || IN_MULTICAST(addr) || IN_BADCLASS(addr);
2087 }
2088
2089 /*
2090 * some_ip_ok - check a wordlist to see if it authorizes any
2091 * IP address(es).
2092 */
2093 static int
some_ip_ok(struct wordlist * addrs)2094 some_ip_ok(struct wordlist *addrs)
2095 {
2096 for (; addrs != 0; addrs = addrs->next) {
2097 if (addrs->word[0] == '-')
2098 break;
2099 if (addrs->word[0] != '!')
2100 return 1; /* some IP address is allowed */
2101 }
2102 return 0;
2103 }
2104
2105 /*
2106 * auth_number - check whether the remote number is allowed to connect.
2107 * Returns 1 if authorized, 0 otherwise.
2108 */
2109 int
auth_number(void)2110 auth_number(void)
2111 {
2112 struct wordlist *wp = permitted_numbers;
2113 int l;
2114
2115 /* Allow all if no authorization list. */
2116 if (!wp)
2117 return 1;
2118
2119 /* Allow if we have a match in the authorization list. */
2120 while (wp) {
2121 /* trailing '*' wildcard */
2122 l = strlen(wp->word);
2123 if ((wp->word)[l - 1] == '*')
2124 l--;
2125 if (!strncasecmp(wp->word, remote_number, l))
2126 return 1;
2127 wp = wp->next;
2128 }
2129
2130 return 0;
2131 }
2132
2133 /*
2134 * check_access - complain if a secret file has too-liberal permissions.
2135 */
2136 static void
check_access(FILE * f,char * filename)2137 check_access(FILE *f, char *filename)
2138 {
2139 struct stat sbuf;
2140
2141 if (fstat(fileno(f), &sbuf) < 0) {
2142 warn("cannot stat secret file %s: %m", filename);
2143 } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
2144 warn("Warning - secret file %s has world and/or group access",
2145 filename);
2146 }
2147 }
2148
2149
2150 /*
2151 * scan_authfile - Scan an authorization file for a secret suitable
2152 * for authenticating `client' on `server'. The return value is -1
2153 * if no secret is found, otherwise >= 0. The return value has
2154 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
2155 * NONWILD_SERVER set if the secret didn't have "*" for the server.
2156 * Any following words on the line up to a "--" (i.e. address authorization
2157 * info) are placed in a wordlist and returned in *addrs. Any
2158 * following words (extra options) are placed in a wordlist and
2159 * returned in *opts.
2160 * We assume secret is NULL or points to MAXWORDLEN bytes of space.
2161 * Flags are non-zero if we need two colons in the secret in order to
2162 * match.
2163 */
2164 static int
scan_authfile(FILE * f,char * client,char * server,char * secret,struct wordlist ** addrs,struct wordlist ** opts,char * filename,int flags)2165 scan_authfile(FILE *f, char *client, char *server,
2166 char *secret, struct wordlist **addrs,
2167 struct wordlist **opts, char *filename,
2168 int flags)
2169 {
2170 int newline, xxx;
2171 int got_flag, best_flag;
2172 FILE *sf;
2173 struct wordlist *ap, *addr_list, *alist, **app;
2174 char word[MAXWORDLEN];
2175 char atfile[MAXWORDLEN];
2176 char lsecret[MAXWORDLEN];
2177 char *cp;
2178
2179 if (addrs != NULL)
2180 *addrs = NULL;
2181 if (opts != NULL)
2182 *opts = NULL;
2183 addr_list = NULL;
2184 if (!getword(f, word, &newline, filename))
2185 return -1; /* file is empty??? */
2186 newline = 1;
2187 best_flag = -1;
2188 for (;;) {
2189 /*
2190 * Skip until we find a word at the start of a line.
2191 */
2192 while (!newline && getword(f, word, &newline, filename))
2193 ;
2194 if (!newline)
2195 break; /* got to end of file */
2196
2197 /*
2198 * Got a client - check if it's a match or a wildcard.
2199 */
2200 got_flag = 0;
2201 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
2202 newline = 0;
2203 continue;
2204 }
2205 if (!ISWILD(word))
2206 got_flag = NONWILD_CLIENT;
2207
2208 /*
2209 * Now get a server and check if it matches.
2210 */
2211 if (!getword(f, word, &newline, filename))
2212 break;
2213 if (newline)
2214 continue;
2215 if (!ISWILD(word)) {
2216 if (server != NULL && strcmp(word, server) != 0)
2217 continue;
2218 got_flag |= NONWILD_SERVER;
2219 }
2220
2221 /*
2222 * Got some sort of a match - see if it's better than what
2223 * we have already.
2224 */
2225 if (got_flag <= best_flag)
2226 continue;
2227
2228 /*
2229 * Get the secret.
2230 */
2231 if (!getword(f, word, &newline, filename))
2232 break;
2233 if (newline)
2234 continue;
2235
2236 /*
2237 * SRP-SHA1 authenticator should never be reading secrets from
2238 * a file. (Authenticatee may, though.)
2239 */
2240 if (flags && ((cp = strchr(word, ':')) == NULL ||
2241 strchr(cp + 1, ':') == NULL))
2242 continue;
2243
2244 if (secret != NULL) {
2245 /*
2246 * Special syntax: @/pathname means read secret from file.
2247 */
2248 if (word[0] == '@' && word[1] == '/') {
2249 strlcpy(atfile, word+1, sizeof(atfile));
2250 if ((sf = fopen(atfile, "r")) == NULL) {
2251 warn("can't open indirect secret file %s", atfile);
2252 continue;
2253 }
2254 check_access(sf, atfile);
2255 if (!getword(sf, word, &xxx, atfile)) {
2256 warn("no secret in indirect secret file %s", atfile);
2257 fclose(sf);
2258 continue;
2259 }
2260 fclose(sf);
2261 }
2262 strlcpy(lsecret, word, sizeof(lsecret));
2263 }
2264
2265 /*
2266 * Now read address authorization info and make a wordlist.
2267 */
2268 app = &alist;
2269 for (;;) {
2270 size_t len;
2271 if (!getword(f, word, &newline, filename) || newline)
2272 break;
2273 len = strlen(word) + 1;
2274 ap = (struct wordlist *)malloc(sizeof(struct wordlist) + len);
2275 if (ap == NULL)
2276 novm("authorized addresses");
2277 ap->word = (char *) (ap + 1);
2278 memcpy(ap->word, word, len);
2279 *app = ap;
2280 app = &ap->next;
2281 }
2282 *app = NULL;
2283
2284 /*
2285 * This is the best so far; remember it.
2286 */
2287 best_flag = got_flag;
2288 if (addr_list)
2289 free_wordlist(addr_list);
2290 addr_list = alist;
2291 if (secret != NULL)
2292 strlcpy(secret, lsecret, MAXWORDLEN);
2293
2294 if (!newline)
2295 break;
2296 }
2297
2298 /* scan for a -- word indicating the start of options */
2299 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
2300 if (strcmp(ap->word, "--") == 0)
2301 break;
2302 /* ap = start of options */
2303 if (ap != NULL) {
2304 ap = ap->next; /* first option */
2305 free(*app); /* free the "--" word */
2306 *app = NULL; /* terminate addr list */
2307 }
2308 if (opts != NULL)
2309 *opts = ap;
2310 else if (ap != NULL)
2311 free_wordlist(ap);
2312 if (addrs != NULL)
2313 *addrs = addr_list;
2314 else if (addr_list != NULL)
2315 free_wordlist(addr_list);
2316
2317 return best_flag;
2318 }
2319
2320 /*
2321 * wordlist_count - return the number of items in a wordlist
2322 */
2323 static int
wordlist_count(struct wordlist * wp)2324 wordlist_count(struct wordlist *wp)
2325 {
2326 int n;
2327
2328 for (n = 0; wp != NULL; wp = wp->next)
2329 ++n;
2330 return n;
2331 }
2332
2333 /*
2334 * free_wordlist - release memory allocated for a wordlist.
2335 */
2336 static void
free_wordlist(struct wordlist * wp)2337 free_wordlist(struct wordlist *wp)
2338 {
2339 struct wordlist *next;
2340
2341 while (wp != NULL) {
2342 next = wp->next;
2343 free(wp);
2344 wp = next;
2345 }
2346 }
2347
2348 /*
2349 * auth_script_done - called when the auth-up or auth-down script
2350 * has finished.
2351 */
2352 static void
auth_script_done(void * arg)2353 auth_script_done(void *arg)
2354 {
2355 auth_script_pid = 0;
2356 switch (auth_script_state) {
2357 case s_up:
2358 if (auth_state == s_down) {
2359 auth_script_state = s_down;
2360 auth_script(_PATH_AUTHDOWN);
2361 }
2362 break;
2363 case s_down:
2364 if (auth_state == s_up) {
2365 auth_script_state = s_up;
2366 auth_script(_PATH_AUTHUP);
2367 }
2368 break;
2369 }
2370 }
2371
2372 /*
2373 * auth_script - execute a script with arguments
2374 * interface-name peer-name real-user tty speed
2375 */
2376 static void
auth_script(char * script)2377 auth_script(char *script)
2378 {
2379 char strspeed[32];
2380 struct passwd *pw;
2381 char struid[32];
2382 char *user_name;
2383 char *argv[8];
2384
2385 if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
2386 user_name = pw->pw_name;
2387 else {
2388 slprintf(struid, sizeof(struid), "%d", getuid());
2389 user_name = struid;
2390 }
2391 slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
2392
2393 argv[0] = script;
2394 argv[1] = ifname;
2395 argv[2] = peer_authname;
2396 argv[3] = user_name;
2397 argv[4] = devnam;
2398 argv[5] = strspeed;
2399 argv[6] = NULL;
2400
2401 auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL, 0);
2402 }
2403
2404
2405 #ifdef USE_EAPTLS
2406 static int
have_eaptls_secret_server(char * client,char * server,int need_ip,int * lacks_ipp)2407 have_eaptls_secret_server(char *client, char *server,
2408 int need_ip, int *lacks_ipp)
2409 {
2410 FILE *f;
2411 int ret;
2412 char *filename;
2413 struct wordlist *addrs;
2414 char servcertfile[MAXWORDLEN];
2415 char clicertfile[MAXWORDLEN];
2416 char cacertfile[MAXWORDLEN];
2417 char pkfile[MAXWORDLEN];
2418
2419 filename = _PATH_EAPTLSSERVFILE;
2420 f = fopen(filename, "r");
2421 if (f == NULL)
2422 return 0;
2423
2424 if (client != NULL && client[0] == 0)
2425 client = NULL;
2426 else if (server != NULL && server[0] == 0)
2427 server = NULL;
2428
2429 ret =
2430 scan_authfile_eaptls(f, client, server, clicertfile, servcertfile,
2431 cacertfile, pkfile, &addrs, NULL, filename,
2432 0);
2433
2434 fclose(f);
2435
2436 /*
2437 if (ret >= 0 && !eaptls_init_ssl(1, cacertfile, servcertfile,
2438 clicertfile, pkfile))
2439 ret = -1;
2440 */
2441
2442 if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
2443 if (lacks_ipp != 0)
2444 *lacks_ipp = 1;
2445 ret = -1;
2446 }
2447 if (addrs != 0)
2448 free_wordlist(addrs);
2449
2450 return ret >= 0;
2451 }
2452
2453
2454 static int
have_eaptls_secret_client(char * client,char * server)2455 have_eaptls_secret_client(char *client, char *server)
2456 {
2457 FILE *f;
2458 int ret;
2459 char *filename;
2460 struct wordlist *addrs = NULL;
2461 char servcertfile[MAXWORDLEN];
2462 char clicertfile[MAXWORDLEN];
2463 char cacertfile[MAXWORDLEN];
2464 char pkfile[MAXWORDLEN];
2465
2466 if (client != NULL && client[0] == 0)
2467 client = NULL;
2468 else if (server != NULL && server[0] == 0)
2469 server = NULL;
2470
2471 if ((cacert_file || ca_path) && cert_file && privkey_file)
2472 return 1;
2473
2474 filename = _PATH_EAPTLSCLIFILE;
2475 f = fopen(filename, "r");
2476 if (f == NULL)
2477 return 0;
2478
2479 ret =
2480 scan_authfile_eaptls(f, client, server, clicertfile, servcertfile,
2481 cacertfile, pkfile, &addrs, NULL, filename,
2482 0);
2483 fclose(f);
2484
2485 /*
2486 if (ret >= 0 && !eaptls_init_ssl(0, cacertfile, clicertfile,
2487 servcertfile, pkfile))
2488 ret = -1;
2489 */
2490
2491 if (addrs != 0)
2492 free_wordlist(addrs);
2493
2494 return ret >= 0;
2495 }
2496
2497
2498 static int
scan_authfile_eaptls(FILE * f,char * client,char * server,char * cli_cert,char * serv_cert,char * ca_cert,char * pk,struct wordlist ** addrs,struct wordlist ** opts,char * filename,int flags)2499 scan_authfile_eaptls(FILE *f, char *client, char *server,
2500 char *cli_cert, char *serv_cert, char *ca_cert,
2501 char *pk, struct wordlist **addrs,
2502 struct wordlist **opts,
2503 char *filename, int flags)
2504 {
2505 int newline;
2506 int got_flag, best_flag;
2507 struct wordlist *ap, *addr_list, *alist, **app;
2508 char word[MAXWORDLEN];
2509
2510 if (addrs != NULL)
2511 *addrs = NULL;
2512 if (opts != NULL)
2513 *opts = NULL;
2514 addr_list = NULL;
2515 if (!getword(f, word, &newline, filename))
2516 return -1; /* file is empty??? */
2517 newline = 1;
2518 best_flag = -1;
2519 for (;;) {
2520 /*
2521 * Skip until we find a word at the start of a line.
2522 */
2523 while (!newline && getword(f, word, &newline, filename));
2524 if (!newline)
2525 break; /* got to end of file */
2526
2527 /*
2528 * Got a client - check if it's a match or a wildcard.
2529 */
2530 got_flag = 0;
2531 if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
2532 newline = 0;
2533 continue;
2534 }
2535 if (!ISWILD(word))
2536 got_flag = NONWILD_CLIENT;
2537
2538 /*
2539 * Now get a server and check if it matches.
2540 */
2541 if (!getword(f, word, &newline, filename))
2542 break;
2543 if (newline)
2544 continue;
2545 if (!ISWILD(word)) {
2546 if (server != NULL && strcmp(word, server) != 0)
2547 continue;
2548 got_flag |= NONWILD_SERVER;
2549 }
2550
2551 /*
2552 * Got some sort of a match - see if it's better than what
2553 * we have already.
2554 */
2555 if (got_flag <= best_flag)
2556 continue;
2557
2558 /*
2559 * Get the cli_cert
2560 */
2561 if (!getword(f, word, &newline, filename))
2562 break;
2563 if (newline)
2564 continue;
2565 if (strcmp(word, "-") != 0) {
2566 strlcpy(cli_cert, word, MAXWORDLEN);
2567 } else
2568 cli_cert[0] = 0;
2569
2570 /*
2571 * Get serv_cert
2572 */
2573 if (!getword(f, word, &newline, filename))
2574 break;
2575 if (newline)
2576 continue;
2577 if (strcmp(word, "-") != 0) {
2578 strlcpy(serv_cert, word, MAXWORDLEN);
2579 } else
2580 serv_cert[0] = 0;
2581
2582 /*
2583 * Get ca_cert
2584 */
2585 if (!getword(f, word, &newline, filename))
2586 break;
2587 if (newline)
2588 continue;
2589 strlcpy(ca_cert, word, MAXWORDLEN);
2590
2591 /*
2592 * Get pk
2593 */
2594 if (!getword(f, word, &newline, filename))
2595 break;
2596 if (newline)
2597 continue;
2598 strlcpy(pk, word, MAXWORDLEN);
2599
2600
2601 /*
2602 * Now read address authorization info and make a wordlist.
2603 */
2604 app = &alist;
2605 for (;;) {
2606 if (!getword(f, word, &newline, filename) || newline)
2607 break;
2608 ap = (struct wordlist *)
2609 malloc(sizeof(struct wordlist) + strlen(word) + 1);
2610 if (ap == NULL)
2611 novm("authorized addresses");
2612 ap->word = (char *) (ap + 1);
2613 strcpy(ap->word, word);
2614 *app = ap;
2615 app = &ap->next;
2616 }
2617 *app = NULL;
2618 /*
2619 * This is the best so far; remember it.
2620 */
2621 best_flag = got_flag;
2622 if (addr_list)
2623 free_wordlist(addr_list);
2624 addr_list = alist;
2625
2626 if (!newline)
2627 break;
2628 }
2629
2630 /* scan for a -- word indicating the start of options */
2631 for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
2632 if (strcmp(ap->word, "--") == 0)
2633 break;
2634 /* ap = start of options */
2635 if (ap != NULL) {
2636 ap = ap->next; /* first option */
2637 free(*app); /* free the "--" word */
2638 *app = NULL; /* terminate addr list */
2639 }
2640 if (opts != NULL)
2641 *opts = ap;
2642 else if (ap != NULL)
2643 free_wordlist(ap);
2644 if (addrs != NULL)
2645 *addrs = addr_list;
2646 else if (addr_list != NULL)
2647 free_wordlist(addr_list);
2648
2649 return best_flag;
2650 }
2651
2652
2653 int
get_eaptls_secret(int unit,char * client,char * server,char * clicertfile,char * servcertfile,char * cacertfile,char * capath,char * pkfile,int am_server)2654 get_eaptls_secret(int unit, char *client, char *server,
2655 char *clicertfile, char *servcertfile, char *cacertfile,
2656 char *capath, char *pkfile, int am_server)
2657 {
2658 FILE *fp;
2659 int ret;
2660 char *filename = NULL;
2661 struct wordlist *addrs = NULL;
2662 struct wordlist *opts = NULL;
2663
2664 /* maybe overkill, but it eases debugging */
2665 bzero(clicertfile, MAXWORDLEN);
2666 bzero(servcertfile, MAXWORDLEN);
2667 bzero(cacertfile, MAXWORDLEN);
2668 bzero(capath, MAXWORDLEN);
2669 bzero(pkfile, MAXWORDLEN);
2670
2671 /* the ca+cert+privkey can also be specified as options */
2672 if (!am_server && (cacert_file || ca_path) && cert_file && privkey_file )
2673 {
2674 strlcpy( clicertfile, cert_file, MAXWORDLEN );
2675 if (cacert_file)
2676 strlcpy( cacertfile, cacert_file, MAXWORDLEN );
2677 if (ca_path)
2678 strlcpy( capath, ca_path, MAXWORDLEN );
2679 strlcpy( pkfile, privkey_file, MAXWORDLEN );
2680 }
2681 else
2682 {
2683 filename = (am_server ? _PATH_EAPTLSSERVFILE : _PATH_EAPTLSCLIFILE);
2684 addrs = NULL;
2685
2686 fp = fopen(filename, "r");
2687 if (fp == NULL)
2688 {
2689 error("Can't open eap-tls secret file %s: %m", filename);
2690 return 0;
2691 }
2692
2693 check_access(fp, filename);
2694
2695 ret = scan_authfile_eaptls(fp, client, server, clicertfile, servcertfile,
2696 cacertfile, pkfile, &addrs, &opts, filename, 0);
2697
2698 fclose(fp);
2699
2700 if (ret < 0) return 0;
2701 }
2702
2703 if (eaptls_passwd_hook)
2704 {
2705 dbglog( "Calling eaptls password hook" );
2706 if ( (*eaptls_passwd_hook)(pkfile, passwd) < 0)
2707 {
2708 error("Unable to obtain EAP-TLS password for %s (%s) from plugin",
2709 client, pkfile);
2710 return 0;
2711 }
2712 }
2713 if (am_server)
2714 set_allowed_addrs(unit, addrs, opts);
2715 else if (opts != NULL)
2716 free_wordlist(opts);
2717 if (addrs != NULL)
2718 free_wordlist(addrs);
2719
2720 return 1;
2721 }
2722 #endif
2723