1 /* $OpenBSD: auth2-pubkey.c,v 1.47 2015/02/17 00:14:05 djm Exp $ */
2 /*
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "includes.h"
27
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <sys/wait.h>
31
32 #include <errno.h>
33 #include <fcntl.h>
34 #ifdef HAVE_PATHS_H
35 # include <paths.h>
36 #endif
37 #include <pwd.h>
38 #include <signal.h>
39 #include <stdio.h>
40 #include <stdarg.h>
41 #include <string.h>
42 #include <time.h>
43 #include <unistd.h>
44 #include <limits.h>
45
46 #include "xmalloc.h"
47 #include "ssh.h"
48 #include "ssh2.h"
49 #include "packet.h"
50 #include "buffer.h"
51 #include "log.h"
52 #include "misc.h"
53 #include "servconf.h"
54 #include "compat.h"
55 #include "key.h"
56 #include "hostfile.h"
57 #include "auth.h"
58 #include "pathnames.h"
59 #include "uidswap.h"
60 #include "auth-options.h"
61 #include "canohost.h"
62 #ifdef GSSAPI
63 #include "ssh-gss.h"
64 #endif
65 #include "monitor_wrap.h"
66 #include "authfile.h"
67 #include "match.h"
68
69 /* import */
70 extern ServerOptions options;
71 extern u_char *session_id2;
72 extern u_int session_id2_len;
73
74 static int
userauth_pubkey(Authctxt * authctxt)75 userauth_pubkey(Authctxt *authctxt)
76 {
77 Buffer b;
78 Key *key = NULL;
79 char *pkalg, *userstyle;
80 u_char *pkblob, *sig;
81 u_int alen, blen, slen;
82 int have_sig, pktype;
83 int authenticated = 0;
84
85 if (!authctxt->valid) {
86 debug2("userauth_pubkey: disabled because of invalid user");
87 return 0;
88 }
89 have_sig = packet_get_char();
90 if (datafellows & SSH_BUG_PKAUTH) {
91 debug2("userauth_pubkey: SSH_BUG_PKAUTH");
92 /* no explicit pkalg given */
93 pkblob = packet_get_string(&blen);
94 buffer_init(&b);
95 buffer_append(&b, pkblob, blen);
96 /* so we have to extract the pkalg from the pkblob */
97 pkalg = buffer_get_string(&b, &alen);
98 buffer_free(&b);
99 } else {
100 pkalg = packet_get_string(&alen);
101 pkblob = packet_get_string(&blen);
102 }
103 pktype = key_type_from_name(pkalg);
104 if (pktype == KEY_UNSPEC) {
105 /* this is perfectly legal */
106 logit("userauth_pubkey: unsupported public key algorithm: %s",
107 pkalg);
108 goto done;
109 }
110 key = key_from_blob(pkblob, blen);
111 if (key == NULL) {
112 error("userauth_pubkey: cannot decode key: %s", pkalg);
113 goto done;
114 }
115 if (key->type != pktype) {
116 error("userauth_pubkey: type mismatch for decoded key "
117 "(received %d, expected %d)", key->type, pktype);
118 goto done;
119 }
120 if (key_type_plain(key->type) == KEY_RSA &&
121 (datafellows & SSH_BUG_RSASIGMD5) != 0) {
122 logit("Refusing RSA key because client uses unsafe "
123 "signature scheme");
124 goto done;
125 }
126 if (auth2_userkey_already_used(authctxt, key)) {
127 logit("refusing previously-used %s key", key_type(key));
128 goto done;
129 }
130 if (match_pattern_list(sshkey_ssh_name(key), options.pubkey_key_types,
131 strlen(options.pubkey_key_types), 0) != 1) {
132 logit("%s: key type %s not in PubkeyAcceptedKeyTypes",
133 __func__, sshkey_ssh_name(key));
134 goto done;
135 }
136
137 if (have_sig) {
138 sig = packet_get_string(&slen);
139 packet_check_eom();
140 buffer_init(&b);
141 if (datafellows & SSH_OLD_SESSIONID) {
142 buffer_append(&b, session_id2, session_id2_len);
143 } else {
144 buffer_put_string(&b, session_id2, session_id2_len);
145 }
146 /* reconstruct packet */
147 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
148 xasprintf(&userstyle, "%s%s%s", authctxt->user,
149 authctxt->style ? ":" : "",
150 authctxt->style ? authctxt->style : "");
151 buffer_put_cstring(&b, userstyle);
152 free(userstyle);
153 buffer_put_cstring(&b,
154 datafellows & SSH_BUG_PKSERVICE ?
155 "ssh-userauth" :
156 authctxt->service);
157 if (datafellows & SSH_BUG_PKAUTH) {
158 buffer_put_char(&b, have_sig);
159 } else {
160 buffer_put_cstring(&b, "publickey");
161 buffer_put_char(&b, have_sig);
162 buffer_put_cstring(&b, pkalg);
163 }
164 buffer_put_string(&b, pkblob, blen);
165 #ifdef DEBUG_PK
166 buffer_dump(&b);
167 #endif
168 pubkey_auth_info(authctxt, key, NULL);
169
170 /* test for correct signature */
171 authenticated = 0;
172 if (PRIVSEP(user_key_allowed(authctxt->pw, key)) &&
173 PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
174 buffer_len(&b))) == 1) {
175 authenticated = 1;
176 /* Record the successful key to prevent reuse */
177 auth2_record_userkey(authctxt, key);
178 key = NULL; /* Don't free below */
179 }
180 buffer_free(&b);
181 free(sig);
182 } else {
183 debug("test whether pkalg/pkblob are acceptable");
184 packet_check_eom();
185
186 /* XXX fake reply and always send PK_OK ? */
187 /*
188 * XXX this allows testing whether a user is allowed
189 * to login: if you happen to have a valid pubkey this
190 * message is sent. the message is NEVER sent at all
191 * if a user is not allowed to login. is this an
192 * issue? -markus
193 */
194 if (PRIVSEP(user_key_allowed(authctxt->pw, key))) {
195 packet_start(SSH2_MSG_USERAUTH_PK_OK);
196 packet_put_string(pkalg, alen);
197 packet_put_string(pkblob, blen);
198 packet_send();
199 packet_write_wait();
200 authctxt->postponed = 1;
201 }
202 }
203 if (authenticated != 1)
204 auth_clear_options();
205 done:
206 debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
207 if (key != NULL)
208 key_free(key);
209 free(pkalg);
210 free(pkblob);
211 return authenticated;
212 }
213
214 void
pubkey_auth_info(Authctxt * authctxt,const Key * key,const char * fmt,...)215 pubkey_auth_info(Authctxt *authctxt, const Key *key, const char *fmt, ...)
216 {
217 char *fp, *extra;
218 va_list ap;
219 int i;
220
221 extra = NULL;
222 if (fmt != NULL) {
223 va_start(ap, fmt);
224 i = vasprintf(&extra, fmt, ap);
225 va_end(ap);
226 if (i < 0 || extra == NULL)
227 fatal("%s: vasprintf failed", __func__);
228 }
229
230 if (key_is_cert(key)) {
231 fp = sshkey_fingerprint(key->cert->signature_key,
232 options.fingerprint_hash, SSH_FP_DEFAULT);
233 auth_info(authctxt, "%s ID %s (serial %llu) CA %s %s%s%s",
234 key_type(key), key->cert->key_id,
235 (unsigned long long)key->cert->serial,
236 key_type(key->cert->signature_key),
237 fp == NULL ? "(null)" : fp,
238 extra == NULL ? "" : ", ", extra == NULL ? "" : extra);
239 free(fp);
240 } else {
241 fp = sshkey_fingerprint(key, options.fingerprint_hash,
242 SSH_FP_DEFAULT);
243 auth_info(authctxt, "%s %s%s%s", key_type(key),
244 fp == NULL ? "(null)" : fp,
245 extra == NULL ? "" : ", ", extra == NULL ? "" : extra);
246 free(fp);
247 }
248 free(extra);
249 }
250
251 static int
match_principals_option(const char * principal_list,struct sshkey_cert * cert)252 match_principals_option(const char *principal_list, struct sshkey_cert *cert)
253 {
254 char *result;
255 u_int i;
256
257 /* XXX percent_expand() sequences for authorized_principals? */
258
259 for (i = 0; i < cert->nprincipals; i++) {
260 if ((result = match_list(cert->principals[i],
261 principal_list, NULL)) != NULL) {
262 debug3("matched principal from key options \"%.100s\"",
263 result);
264 free(result);
265 return 1;
266 }
267 }
268 return 0;
269 }
270
271 static int
match_principals_file(char * file,struct passwd * pw,struct sshkey_cert * cert)272 match_principals_file(char *file, struct passwd *pw, struct sshkey_cert *cert)
273 {
274 FILE *f;
275 char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts;
276 u_long linenum = 0;
277 u_int i;
278
279 temporarily_use_uid(pw);
280 debug("trying authorized principals file %s", file);
281 if ((f = auth_openprincipals(file, pw, options.strict_modes)) == NULL) {
282 restore_uid();
283 return 0;
284 }
285 while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
286 /* Skip leading whitespace. */
287 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
288 ;
289 /* Skip blank and comment lines. */
290 if ((ep = strchr(cp, '#')) != NULL)
291 *ep = '\0';
292 if (!*cp || *cp == '\n')
293 continue;
294 /* Trim trailing whitespace. */
295 ep = cp + strlen(cp) - 1;
296 while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
297 *ep-- = '\0';
298 /*
299 * If the line has internal whitespace then assume it has
300 * key options.
301 */
302 line_opts = NULL;
303 if ((ep = strrchr(cp, ' ')) != NULL ||
304 (ep = strrchr(cp, '\t')) != NULL) {
305 for (; *ep == ' ' || *ep == '\t'; ep++)
306 ;
307 line_opts = cp;
308 cp = ep;
309 }
310 for (i = 0; i < cert->nprincipals; i++) {
311 if (strcmp(cp, cert->principals[i]) == 0) {
312 debug3("matched principal \"%.100s\" "
313 "from file \"%s\" on line %lu",
314 cert->principals[i], file, linenum);
315 if (auth_parse_options(pw, line_opts,
316 file, linenum) != 1)
317 continue;
318 fclose(f);
319 restore_uid();
320 return 1;
321 }
322 }
323 }
324 fclose(f);
325 restore_uid();
326 return 0;
327 }
328
329 /*
330 * Checks whether key is allowed in authorized_keys-format file,
331 * returns 1 if the key is allowed or 0 otherwise.
332 */
333 static int
check_authkeys_file(FILE * f,char * file,Key * key,struct passwd * pw)334 check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
335 {
336 char line[SSH_MAX_PUBKEY_BYTES];
337 const char *reason;
338 int found_key = 0;
339 u_long linenum = 0;
340 Key *found;
341 char *fp;
342
343 found_key = 0;
344
345 found = NULL;
346 while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
347 char *cp, *key_options = NULL;
348 if (found != NULL)
349 key_free(found);
350 found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
351 auth_clear_options();
352
353 /* Skip leading whitespace, empty and comment lines. */
354 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
355 ;
356 if (!*cp || *cp == '\n' || *cp == '#')
357 continue;
358
359 if (key_read(found, &cp) != 1) {
360 /* no key? check if there are options for this key */
361 int quoted = 0;
362 debug2("user_key_allowed: check options: '%s'", cp);
363 key_options = cp;
364 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
365 if (*cp == '\\' && cp[1] == '"')
366 cp++; /* Skip both */
367 else if (*cp == '"')
368 quoted = !quoted;
369 }
370 /* Skip remaining whitespace. */
371 for (; *cp == ' ' || *cp == '\t'; cp++)
372 ;
373 if (key_read(found, &cp) != 1) {
374 debug2("user_key_allowed: advance: '%s'", cp);
375 /* still no key? advance to next line*/
376 continue;
377 }
378 }
379 if (key_is_cert(key)) {
380 if (!key_equal(found, key->cert->signature_key))
381 continue;
382 if (auth_parse_options(pw, key_options, file,
383 linenum) != 1)
384 continue;
385 if (!key_is_cert_authority)
386 continue;
387 if ((fp = sshkey_fingerprint(found,
388 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
389 continue;
390 debug("matching CA found: file %s, line %lu, %s %s",
391 file, linenum, key_type(found), fp);
392 /*
393 * If the user has specified a list of principals as
394 * a key option, then prefer that list to matching
395 * their username in the certificate principals list.
396 */
397 if (authorized_principals != NULL &&
398 !match_principals_option(authorized_principals,
399 key->cert)) {
400 reason = "Certificate does not contain an "
401 "authorized principal";
402 fail_reason:
403 free(fp);
404 error("%s", reason);
405 auth_debug_add("%s", reason);
406 continue;
407 }
408 if (key_cert_check_authority(key, 0, 0,
409 authorized_principals == NULL ? pw->pw_name : NULL,
410 &reason) != 0)
411 goto fail_reason;
412 if (auth_cert_options(key, pw) != 0) {
413 free(fp);
414 continue;
415 }
416 verbose("Accepted certificate ID \"%s\" "
417 "signed by %s CA %s via %s", key->cert->key_id,
418 key_type(found), fp, file);
419 free(fp);
420 found_key = 1;
421 break;
422 } else if (key_equal(found, key)) {
423 if (auth_parse_options(pw, key_options, file,
424 linenum) != 1)
425 continue;
426 if (key_is_cert_authority)
427 continue;
428 if ((fp = sshkey_fingerprint(found,
429 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
430 continue;
431 debug("matching key found: file %s, line %lu %s %s",
432 file, linenum, key_type(found), fp);
433 free(fp);
434 found_key = 1;
435 break;
436 }
437 }
438 if (found != NULL)
439 key_free(found);
440 if (!found_key)
441 debug2("key not found");
442 return found_key;
443 }
444
445 /* Authenticate a certificate key against TrustedUserCAKeys */
446 static int
user_cert_trusted_ca(struct passwd * pw,Key * key)447 user_cert_trusted_ca(struct passwd *pw, Key *key)
448 {
449 char *ca_fp, *principals_file = NULL;
450 const char *reason;
451 int ret = 0;
452
453 if (!key_is_cert(key) || options.trusted_user_ca_keys == NULL)
454 return 0;
455
456 if ((ca_fp = sshkey_fingerprint(key->cert->signature_key,
457 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
458 return 0;
459
460 if (sshkey_in_file(key->cert->signature_key,
461 options.trusted_user_ca_keys, 1, 0) != 0) {
462 debug2("%s: CA %s %s is not listed in %s", __func__,
463 key_type(key->cert->signature_key), ca_fp,
464 options.trusted_user_ca_keys);
465 goto out;
466 }
467 /*
468 * If AuthorizedPrincipals is in use, then compare the certificate
469 * principals against the names in that file rather than matching
470 * against the username.
471 */
472 if ((principals_file = authorized_principals_file(pw)) != NULL) {
473 if (!match_principals_file(principals_file, pw, key->cert)) {
474 reason = "Certificate does not contain an "
475 "authorized principal";
476 fail_reason:
477 error("%s", reason);
478 auth_debug_add("%s", reason);
479 goto out;
480 }
481 }
482 if (key_cert_check_authority(key, 0, 1,
483 principals_file == NULL ? pw->pw_name : NULL, &reason) != 0)
484 goto fail_reason;
485 if (auth_cert_options(key, pw) != 0)
486 goto out;
487
488 verbose("Accepted certificate ID \"%s\" signed by %s CA %s via %s",
489 key->cert->key_id, key_type(key->cert->signature_key), ca_fp,
490 options.trusted_user_ca_keys);
491 ret = 1;
492
493 out:
494 free(principals_file);
495 free(ca_fp);
496 return ret;
497 }
498
499 /*
500 * Checks whether key is allowed in file.
501 * returns 1 if the key is allowed or 0 otherwise.
502 */
503 static int
user_key_allowed2(struct passwd * pw,Key * key,char * file)504 user_key_allowed2(struct passwd *pw, Key *key, char *file)
505 {
506 FILE *f;
507 int found_key = 0;
508
509 /* Temporarily use the user's uid. */
510 temporarily_use_uid(pw);
511
512 debug("trying public key file %s", file);
513 if ((f = auth_openkeyfile(file, pw, options.strict_modes)) != NULL) {
514 found_key = check_authkeys_file(f, file, key, pw);
515 fclose(f);
516 }
517
518 restore_uid();
519 return found_key;
520 }
521
522 /*
523 * Checks whether key is allowed in output of command.
524 * returns 1 if the key is allowed or 0 otherwise.
525 */
526 static int
user_key_command_allowed2(struct passwd * user_pw,Key * key)527 user_key_command_allowed2(struct passwd *user_pw, Key *key)
528 {
529 FILE *f;
530 int ok, found_key = 0;
531 struct passwd *pw;
532 struct stat st;
533 int status, devnull, p[2], i;
534 pid_t pid;
535 char *username, errmsg[512];
536
537 if (options.authorized_keys_command == NULL ||
538 options.authorized_keys_command[0] != '/')
539 return 0;
540
541 if (options.authorized_keys_command_user == NULL) {
542 error("No user for AuthorizedKeysCommand specified, skipping");
543 return 0;
544 }
545
546 username = percent_expand(options.authorized_keys_command_user,
547 "u", user_pw->pw_name, (char *)NULL);
548 pw = getpwnam(username);
549 if (pw == NULL) {
550 error("AuthorizedKeysCommandUser \"%s\" not found: %s",
551 username, strerror(errno));
552 free(username);
553 return 0;
554 }
555 free(username);
556
557 temporarily_use_uid(pw);
558
559 if (stat(options.authorized_keys_command, &st) < 0) {
560 error("Could not stat AuthorizedKeysCommand \"%s\": %s",
561 options.authorized_keys_command, strerror(errno));
562 goto out;
563 }
564 if (auth_secure_path(options.authorized_keys_command, &st, NULL, 0,
565 errmsg, sizeof(errmsg)) != 0) {
566 error("Unsafe AuthorizedKeysCommand: %s", errmsg);
567 goto out;
568 }
569
570 if (pipe(p) != 0) {
571 error("%s: pipe: %s", __func__, strerror(errno));
572 goto out;
573 }
574
575 debug3("Running AuthorizedKeysCommand: \"%s %s\" as \"%s\"",
576 options.authorized_keys_command, user_pw->pw_name, pw->pw_name);
577
578 /*
579 * Don't want to call this in the child, where it can fatal() and
580 * run cleanup_exit() code.
581 */
582 restore_uid();
583
584 switch ((pid = fork())) {
585 case -1: /* error */
586 error("%s: fork: %s", __func__, strerror(errno));
587 close(p[0]);
588 close(p[1]);
589 return 0;
590 case 0: /* child */
591 for (i = 0; i < NSIG; i++)
592 signal(i, SIG_DFL);
593
594 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
595 error("%s: open %s: %s", __func__, _PATH_DEVNULL,
596 strerror(errno));
597 _exit(1);
598 }
599 /* Keep stderr around a while longer to catch errors */
600 if (dup2(devnull, STDIN_FILENO) == -1 ||
601 dup2(p[1], STDOUT_FILENO) == -1) {
602 error("%s: dup2: %s", __func__, strerror(errno));
603 _exit(1);
604 }
605 closefrom(STDERR_FILENO + 1);
606
607 /* Don't use permanently_set_uid() here to avoid fatal() */
608 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
609 error("setresgid %u: %s", (u_int)pw->pw_gid,
610 strerror(errno));
611 _exit(1);
612 }
613 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
614 error("setresuid %u: %s", (u_int)pw->pw_uid,
615 strerror(errno));
616 _exit(1);
617 }
618 /* stdin is pointed to /dev/null at this point */
619 if (dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
620 error("%s: dup2: %s", __func__, strerror(errno));
621 _exit(1);
622 }
623
624 execl(options.authorized_keys_command,
625 options.authorized_keys_command, user_pw->pw_name, NULL);
626
627 error("AuthorizedKeysCommand %s exec failed: %s",
628 options.authorized_keys_command, strerror(errno));
629 _exit(127);
630 default: /* parent */
631 break;
632 }
633
634 temporarily_use_uid(pw);
635
636 close(p[1]);
637 if ((f = fdopen(p[0], "r")) == NULL) {
638 error("%s: fdopen: %s", __func__, strerror(errno));
639 close(p[0]);
640 /* Don't leave zombie child */
641 kill(pid, SIGTERM);
642 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
643 ;
644 goto out;
645 }
646 ok = check_authkeys_file(f, options.authorized_keys_command, key, pw);
647 fclose(f);
648
649 while (waitpid(pid, &status, 0) == -1) {
650 if (errno != EINTR) {
651 error("%s: waitpid: %s", __func__, strerror(errno));
652 goto out;
653 }
654 }
655 if (WIFSIGNALED(status)) {
656 error("AuthorizedKeysCommand %s exited on signal %d",
657 options.authorized_keys_command, WTERMSIG(status));
658 goto out;
659 } else if (WEXITSTATUS(status) != 0) {
660 error("AuthorizedKeysCommand %s returned status %d",
661 options.authorized_keys_command, WEXITSTATUS(status));
662 goto out;
663 }
664 found_key = ok;
665 out:
666 restore_uid();
667 return found_key;
668 }
669
670 /*
671 * Check whether key authenticates and authorises the user.
672 */
673 int
user_key_allowed(struct passwd * pw,Key * key)674 user_key_allowed(struct passwd *pw, Key *key)
675 {
676 u_int success, i;
677 char *file;
678
679 if (auth_key_is_revoked(key))
680 return 0;
681 if (key_is_cert(key) && auth_key_is_revoked(key->cert->signature_key))
682 return 0;
683
684 success = user_cert_trusted_ca(pw, key);
685 if (success)
686 return success;
687
688 success = user_key_command_allowed2(pw, key);
689 if (success > 0)
690 return success;
691
692 for (i = 0; !success && i < options.num_authkeys_files; i++) {
693
694 if (strcasecmp(options.authorized_keys_files[i], "none") == 0)
695 continue;
696 file = expand_authorized_keys(
697 options.authorized_keys_files[i], pw);
698
699 success = user_key_allowed2(pw, key, file);
700 free(file);
701 }
702
703 return success;
704 }
705
706 /* Records a public key in the list of previously-successful keys */
707 void
auth2_record_userkey(Authctxt * authctxt,struct sshkey * key)708 auth2_record_userkey(Authctxt *authctxt, struct sshkey *key)
709 {
710 struct sshkey **tmp;
711
712 if (authctxt->nprev_userkeys >= INT_MAX ||
713 (tmp = reallocarray(authctxt->prev_userkeys,
714 authctxt->nprev_userkeys + 1, sizeof(*tmp))) == NULL)
715 fatal("%s: reallocarray failed", __func__);
716 authctxt->prev_userkeys = tmp;
717 authctxt->prev_userkeys[authctxt->nprev_userkeys] = key;
718 authctxt->nprev_userkeys++;
719 }
720
721 /* Checks whether a key has already been used successfully for authentication */
722 int
auth2_userkey_already_used(Authctxt * authctxt,struct sshkey * key)723 auth2_userkey_already_used(Authctxt *authctxt, struct sshkey *key)
724 {
725 u_int i;
726
727 for (i = 0; i < authctxt->nprev_userkeys; i++) {
728 if (sshkey_equal_public(key, authctxt->prev_userkeys[i])) {
729 return 1;
730 }
731 }
732 return 0;
733 }
734
735 Authmethod method_pubkey = {
736 "publickey",
737 userauth_pubkey,
738 &options.pubkey_authentication
739 };
740