xref: /freebsd/crypto/openssh/auth.c (revision 243e928310d073338c5ec089f0dce238a80b9866)
1 /* $OpenBSD: auth.c,v 1.113 2015/08/21 03:42:19 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 __RCSID("$FreeBSD$");
28 
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 
32 #include <netinet/in.h>
33 
34 #include <errno.h>
35 #include <fcntl.h>
36 #ifdef HAVE_PATHS_H
37 # include <paths.h>
38 #endif
39 #include <pwd.h>
40 #ifdef HAVE_LOGIN_H
41 #include <login.h>
42 #endif
43 #ifdef USE_SHADOW
44 #include <shadow.h>
45 #endif
46 #ifdef HAVE_LIBGEN_H
47 #include <libgen.h>
48 #endif
49 #include <stdarg.h>
50 #include <stdio.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <limits.h>
54 
55 #include "xmalloc.h"
56 #include "match.h"
57 #include "groupaccess.h"
58 #include "log.h"
59 #include "buffer.h"
60 #include "misc.h"
61 #include "servconf.h"
62 #include "key.h"
63 #include "hostfile.h"
64 #include "auth.h"
65 #include "auth-options.h"
66 #include "canohost.h"
67 #include "uidswap.h"
68 #include "packet.h"
69 #include "loginrec.h"
70 #ifdef GSSAPI
71 #include "ssh-gss.h"
72 #endif
73 #include "authfile.h"
74 #include "monitor_wrap.h"
75 #include "authfile.h"
76 #include "ssherr.h"
77 #include "compat.h"
78 
79 /* import */
80 extern ServerOptions options;
81 extern int use_privsep;
82 extern Buffer loginmsg;
83 extern struct passwd *privsep_pw;
84 
85 /* Debugging messages */
86 Buffer auth_debug;
87 int auth_debug_init;
88 
89 /*
90  * Check if the user is allowed to log in via ssh. If user is listed
91  * in DenyUsers or one of user's groups is listed in DenyGroups, false
92  * will be returned. If AllowUsers isn't empty and user isn't listed
93  * there, or if AllowGroups isn't empty and one of user's groups isn't
94  * listed there, false will be returned.
95  * If the user's shell is not executable, false will be returned.
96  * Otherwise true is returned.
97  */
98 int
99 allowed_user(struct passwd * pw)
100 {
101 	struct stat st;
102 	const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
103 	u_int i;
104 #ifdef USE_SHADOW
105 	struct spwd *spw = NULL;
106 #endif
107 
108 	/* Shouldn't be called if pw is NULL, but better safe than sorry... */
109 	if (!pw || !pw->pw_name)
110 		return 0;
111 
112 #ifdef USE_SHADOW
113 	if (!options.use_pam)
114 		spw = getspnam(pw->pw_name);
115 #ifdef HAS_SHADOW_EXPIRE
116 	if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw))
117 		return 0;
118 #endif /* HAS_SHADOW_EXPIRE */
119 #endif /* USE_SHADOW */
120 
121 	/* grab passwd field for locked account check */
122 	passwd = pw->pw_passwd;
123 #ifdef USE_SHADOW
124 	if (spw != NULL)
125 #ifdef USE_LIBIAF
126 		passwd = get_iaf_password(pw);
127 #else
128 		passwd = spw->sp_pwdp;
129 #endif /* USE_LIBIAF */
130 #endif
131 
132 	/* check for locked account */
133 	if (!options.use_pam && passwd && *passwd) {
134 		int locked = 0;
135 
136 #ifdef LOCKED_PASSWD_STRING
137 		if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0)
138 			 locked = 1;
139 #endif
140 #ifdef LOCKED_PASSWD_PREFIX
141 		if (strncmp(passwd, LOCKED_PASSWD_PREFIX,
142 		    strlen(LOCKED_PASSWD_PREFIX)) == 0)
143 			 locked = 1;
144 #endif
145 #ifdef LOCKED_PASSWD_SUBSTR
146 		if (strstr(passwd, LOCKED_PASSWD_SUBSTR))
147 			locked = 1;
148 #endif
149 #ifdef USE_LIBIAF
150 		free((void *) passwd);
151 #endif /* USE_LIBIAF */
152 		if (locked) {
153 			logit("User %.100s not allowed because account is locked",
154 			    pw->pw_name);
155 			return 0;
156 		}
157 	}
158 
159 	/*
160 	 * Deny if shell does not exist or is not executable unless we
161 	 * are chrooting.
162 	 */
163 	if (options.chroot_directory == NULL ||
164 	    strcasecmp(options.chroot_directory, "none") == 0) {
165 		char *shell = xstrdup((pw->pw_shell[0] == '\0') ?
166 		    _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */
167 
168 		if (stat(shell, &st) != 0) {
169 			logit("User %.100s not allowed because shell %.100s "
170 			    "does not exist", pw->pw_name, shell);
171 			free(shell);
172 			return 0;
173 		}
174 		if (S_ISREG(st.st_mode) == 0 ||
175 		    (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) {
176 			logit("User %.100s not allowed because shell %.100s "
177 			    "is not executable", pw->pw_name, shell);
178 			free(shell);
179 			return 0;
180 		}
181 		free(shell);
182 	}
183 
184 	if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
185 	    options.num_deny_groups > 0 || options.num_allow_groups > 0) {
186 		hostname = get_canonical_hostname(options.use_dns);
187 		ipaddr = get_remote_ipaddr();
188 	}
189 
190 	/* Return false if user is listed in DenyUsers */
191 	if (options.num_deny_users > 0) {
192 		for (i = 0; i < options.num_deny_users; i++)
193 			if (match_user(pw->pw_name, hostname, ipaddr,
194 			    options.deny_users[i])) {
195 				logit("User %.100s from %.100s not allowed "
196 				    "because listed in DenyUsers",
197 				    pw->pw_name, hostname);
198 				return 0;
199 			}
200 	}
201 	/* Return false if AllowUsers isn't empty and user isn't listed there */
202 	if (options.num_allow_users > 0) {
203 		for (i = 0; i < options.num_allow_users; i++)
204 			if (match_user(pw->pw_name, hostname, ipaddr,
205 			    options.allow_users[i]))
206 				break;
207 		/* i < options.num_allow_users iff we break for loop */
208 		if (i >= options.num_allow_users) {
209 			logit("User %.100s from %.100s not allowed because "
210 			    "not listed in AllowUsers", pw->pw_name, hostname);
211 			return 0;
212 		}
213 	}
214 	if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
215 		/* Get the user's group access list (primary and supplementary) */
216 		if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
217 			logit("User %.100s from %.100s not allowed because "
218 			    "not in any group", pw->pw_name, hostname);
219 			return 0;
220 		}
221 
222 		/* Return false if one of user's groups is listed in DenyGroups */
223 		if (options.num_deny_groups > 0)
224 			if (ga_match(options.deny_groups,
225 			    options.num_deny_groups)) {
226 				ga_free();
227 				logit("User %.100s from %.100s not allowed "
228 				    "because a group is listed in DenyGroups",
229 				    pw->pw_name, hostname);
230 				return 0;
231 			}
232 		/*
233 		 * Return false if AllowGroups isn't empty and one of user's groups
234 		 * isn't listed there
235 		 */
236 		if (options.num_allow_groups > 0)
237 			if (!ga_match(options.allow_groups,
238 			    options.num_allow_groups)) {
239 				ga_free();
240 				logit("User %.100s from %.100s not allowed "
241 				    "because none of user's groups are listed "
242 				    "in AllowGroups", pw->pw_name, hostname);
243 				return 0;
244 			}
245 		ga_free();
246 	}
247 
248 #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER
249 	if (!sys_auth_allowed_user(pw, &loginmsg))
250 		return 0;
251 #endif
252 
253 	/* We found no reason not to let this user try to log on... */
254 	return 1;
255 }
256 
257 void
258 auth_info(Authctxt *authctxt, const char *fmt, ...)
259 {
260 	va_list ap;
261         int i;
262 
263 	free(authctxt->info);
264 	authctxt->info = NULL;
265 
266 	va_start(ap, fmt);
267 	i = vasprintf(&authctxt->info, fmt, ap);
268 	va_end(ap);
269 
270 	if (i < 0 || authctxt->info == NULL)
271 		fatal("vasprintf failed");
272 }
273 
274 void
275 auth_log(Authctxt *authctxt, int authenticated, int partial,
276     const char *method, const char *submethod)
277 {
278 	void (*authlog) (const char *fmt,...) = verbose;
279 	char *authmsg;
280 
281 	if (use_privsep && !mm_is_monitor() && !authctxt->postponed)
282 		return;
283 
284 	/* Raise logging level */
285 	if (authenticated == 1 ||
286 	    !authctxt->valid ||
287 	    authctxt->failures >= options.max_authtries / 2 ||
288 	    strcmp(method, "password") == 0)
289 		authlog = logit;
290 
291 	if (authctxt->postponed)
292 		authmsg = "Postponed";
293 	else if (partial)
294 		authmsg = "Partial";
295 	else
296 		authmsg = authenticated ? "Accepted" : "Failed";
297 
298 	authlog("%s %s%s%s for %s%.100s from %.200s port %d %s%s%s",
299 	    authmsg,
300 	    method,
301 	    submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod,
302 	    authctxt->valid ? "" : "invalid user ",
303 	    authctxt->user,
304 	    get_remote_ipaddr(),
305 	    get_remote_port(),
306 	    compat20 ? "ssh2" : "ssh1",
307 	    authctxt->info != NULL ? ": " : "",
308 	    authctxt->info != NULL ? authctxt->info : "");
309 	free(authctxt->info);
310 	authctxt->info = NULL;
311 
312 #ifdef CUSTOM_FAILED_LOGIN
313 	if (authenticated == 0 && !authctxt->postponed &&
314 	    (strcmp(method, "password") == 0 ||
315 	    strncmp(method, "keyboard-interactive", 20) == 0 ||
316 	    strcmp(method, "challenge-response") == 0))
317 		record_failed_login(authctxt->user,
318 		    get_canonical_hostname(options.use_dns), "ssh");
319 # ifdef WITH_AIXAUTHENTICATE
320 	if (authenticated)
321 		sys_auth_record_login(authctxt->user,
322 		    get_canonical_hostname(options.use_dns), "ssh", &loginmsg);
323 # endif
324 #endif
325 #ifdef SSH_AUDIT_EVENTS
326 	if (authenticated == 0 && !authctxt->postponed)
327 		audit_event(audit_classify_auth(method));
328 #endif
329 }
330 
331 
332 void
333 auth_maxtries_exceeded(Authctxt *authctxt)
334 {
335 	error("maximum authentication attempts exceeded for "
336 	    "%s%.100s from %.200s port %d %s",
337 	    authctxt->valid ? "" : "invalid user ",
338 	    authctxt->user,
339 	    get_remote_ipaddr(),
340 	    get_remote_port(),
341 	    compat20 ? "ssh2" : "ssh1");
342 	packet_disconnect("Too many authentication failures");
343 	/* NOTREACHED */
344 }
345 
346 /*
347  * Check whether root logins are disallowed.
348  */
349 int
350 auth_root_allowed(const char *method)
351 {
352 	switch (options.permit_root_login) {
353 	case PERMIT_YES:
354 		return 1;
355 	case PERMIT_NO_PASSWD:
356 		if (strcmp(method, "publickey") == 0 ||
357 		    strcmp(method, "hostbased") == 0 ||
358 		    strcmp(method, "gssapi-with-mic") == 0)
359 			return 1;
360 		break;
361 	case PERMIT_FORCED_ONLY:
362 		if (forced_command) {
363 			logit("Root login accepted for forced command.");
364 			return 1;
365 		}
366 		break;
367 	}
368 	logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
369 	return 0;
370 }
371 
372 
373 /*
374  * Given a template and a passwd structure, build a filename
375  * by substituting % tokenised options. Currently, %% becomes '%',
376  * %h becomes the home directory and %u the username.
377  *
378  * This returns a buffer allocated by xmalloc.
379  */
380 char *
381 expand_authorized_keys(const char *filename, struct passwd *pw)
382 {
383 	char *file, ret[PATH_MAX];
384 	int i;
385 
386 	file = percent_expand(filename, "h", pw->pw_dir,
387 	    "u", pw->pw_name, (char *)NULL);
388 
389 	/*
390 	 * Ensure that filename starts anchored. If not, be backward
391 	 * compatible and prepend the '%h/'
392 	 */
393 	if (*file == '/')
394 		return (file);
395 
396 	i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file);
397 	if (i < 0 || (size_t)i >= sizeof(ret))
398 		fatal("expand_authorized_keys: path too long");
399 	free(file);
400 	return (xstrdup(ret));
401 }
402 
403 char *
404 authorized_principals_file(struct passwd *pw)
405 {
406 	if (options.authorized_principals_file == NULL)
407 		return NULL;
408 	return expand_authorized_keys(options.authorized_principals_file, pw);
409 }
410 
411 /* return ok if key exists in sysfile or userfile */
412 HostStatus
413 check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
414     const char *sysfile, const char *userfile)
415 {
416 	char *user_hostfile;
417 	struct stat st;
418 	HostStatus host_status;
419 	struct hostkeys *hostkeys;
420 	const struct hostkey_entry *found;
421 
422 	hostkeys = init_hostkeys();
423 	load_hostkeys(hostkeys, host, sysfile);
424 	if (userfile != NULL) {
425 		user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
426 		if (options.strict_modes &&
427 		    (stat(user_hostfile, &st) == 0) &&
428 		    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
429 		    (st.st_mode & 022) != 0)) {
430 			logit("Authentication refused for %.100s: "
431 			    "bad owner or modes for %.200s",
432 			    pw->pw_name, user_hostfile);
433 			auth_debug_add("Ignored %.200s: bad ownership or modes",
434 			    user_hostfile);
435 		} else {
436 			temporarily_use_uid(pw);
437 			load_hostkeys(hostkeys, host, user_hostfile);
438 			restore_uid();
439 		}
440 		free(user_hostfile);
441 	}
442 	host_status = check_key_in_hostkeys(hostkeys, key, &found);
443 	if (host_status == HOST_REVOKED)
444 		error("WARNING: revoked key for %s attempted authentication",
445 		    found->host);
446 	else if (host_status == HOST_OK)
447 		debug("%s: key for %s found at %s:%ld", __func__,
448 		    found->host, found->file, found->line);
449 	else
450 		debug("%s: key for host %s not found", __func__, host);
451 
452 	free_hostkeys(hostkeys);
453 
454 	return host_status;
455 }
456 
457 /*
458  * Check a given path for security. This is defined as all components
459  * of the path to the file must be owned by either the owner of
460  * of the file or root and no directories must be group or world writable.
461  *
462  * XXX Should any specific check be done for sym links ?
463  *
464  * Takes a file name, its stat information (preferably from fstat() to
465  * avoid races), the uid of the expected owner, their home directory and an
466  * error buffer plus max size as arguments.
467  *
468  * Returns 0 on success and -1 on failure
469  */
470 int
471 auth_secure_path(const char *name, struct stat *stp, const char *pw_dir,
472     uid_t uid, char *err, size_t errlen)
473 {
474 	char buf[PATH_MAX], homedir[PATH_MAX];
475 	char *cp;
476 	int comparehome = 0;
477 	struct stat st;
478 
479 	if (realpath(name, buf) == NULL) {
480 		snprintf(err, errlen, "realpath %s failed: %s", name,
481 		    strerror(errno));
482 		return -1;
483 	}
484 	if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
485 		comparehome = 1;
486 
487 	if (!S_ISREG(stp->st_mode)) {
488 		snprintf(err, errlen, "%s is not a regular file", buf);
489 		return -1;
490 	}
491 	if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) ||
492 	    (stp->st_mode & 022) != 0) {
493 		snprintf(err, errlen, "bad ownership or modes for file %s",
494 		    buf);
495 		return -1;
496 	}
497 
498 	/* for each component of the canonical path, walking upwards */
499 	for (;;) {
500 		if ((cp = dirname(buf)) == NULL) {
501 			snprintf(err, errlen, "dirname() failed");
502 			return -1;
503 		}
504 		strlcpy(buf, cp, sizeof(buf));
505 
506 		if (stat(buf, &st) < 0 ||
507 		    (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) ||
508 		    (st.st_mode & 022) != 0) {
509 			snprintf(err, errlen,
510 			    "bad ownership or modes for directory %s", buf);
511 			return -1;
512 		}
513 
514 		/* If are past the homedir then we can stop */
515 		if (comparehome && strcmp(homedir, buf) == 0)
516 			break;
517 
518 		/*
519 		 * dirname should always complete with a "/" path,
520 		 * but we can be paranoid and check for "." too
521 		 */
522 		if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
523 			break;
524 	}
525 	return 0;
526 }
527 
528 /*
529  * Version of secure_path() that accepts an open file descriptor to
530  * avoid races.
531  *
532  * Returns 0 on success and -1 on failure
533  */
534 static int
535 secure_filename(FILE *f, const char *file, struct passwd *pw,
536     char *err, size_t errlen)
537 {
538 	struct stat st;
539 
540 	/* check the open file to avoid races */
541 	if (fstat(fileno(f), &st) < 0) {
542 		snprintf(err, errlen, "cannot stat file %s: %s",
543 		    file, strerror(errno));
544 		return -1;
545 	}
546 	return auth_secure_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
547 }
548 
549 static FILE *
550 auth_openfile(const char *file, struct passwd *pw, int strict_modes,
551     int log_missing, char *file_type)
552 {
553 	char line[1024];
554 	struct stat st;
555 	int fd;
556 	FILE *f;
557 
558 	if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) {
559 		if (log_missing || errno != ENOENT)
560 			debug("Could not open %s '%s': %s", file_type, file,
561 			   strerror(errno));
562 		return NULL;
563 	}
564 
565 	if (fstat(fd, &st) < 0) {
566 		close(fd);
567 		return NULL;
568 	}
569 	if (!S_ISREG(st.st_mode)) {
570 		logit("User %s %s %s is not a regular file",
571 		    pw->pw_name, file_type, file);
572 		close(fd);
573 		return NULL;
574 	}
575 	unset_nonblock(fd);
576 	if ((f = fdopen(fd, "r")) == NULL) {
577 		close(fd);
578 		return NULL;
579 	}
580 	if (strict_modes &&
581 	    secure_filename(f, file, pw, line, sizeof(line)) != 0) {
582 		fclose(f);
583 		logit("Authentication refused: %s", line);
584 		auth_debug_add("Ignored %s: %s", file_type, line);
585 		return NULL;
586 	}
587 
588 	return f;
589 }
590 
591 
592 FILE *
593 auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes)
594 {
595 	return auth_openfile(file, pw, strict_modes, 1, "authorized keys");
596 }
597 
598 FILE *
599 auth_openprincipals(const char *file, struct passwd *pw, int strict_modes)
600 {
601 	return auth_openfile(file, pw, strict_modes, 0,
602 	    "authorized principals");
603 }
604 
605 struct passwd *
606 getpwnamallow(const char *user)
607 {
608 #ifdef HAVE_LOGIN_CAP
609 	extern login_cap_t *lc;
610 #ifdef BSD_AUTH
611 	auth_session_t *as;
612 #endif
613 #endif
614 	struct passwd *pw;
615 	struct connection_info *ci = get_connection_info(1, options.use_dns);
616 
617 	ci->user = user;
618 	parse_server_match_config(&options, ci);
619 
620 #if defined(_AIX) && defined(HAVE_SETAUTHDB)
621 	aix_setauthdb(user);
622 #endif
623 
624 	pw = getpwnam(user);
625 
626 #if defined(_AIX) && defined(HAVE_SETAUTHDB)
627 	aix_restoreauthdb();
628 #endif
629 #ifdef HAVE_CYGWIN
630 	/*
631 	 * Windows usernames are case-insensitive.  To avoid later problems
632 	 * when trying to match the username, the user is only allowed to
633 	 * login if the username is given in the same case as stored in the
634 	 * user database.
635 	 */
636 	if (pw != NULL && strcmp(user, pw->pw_name) != 0) {
637 		logit("Login name %.100s does not match stored username %.100s",
638 		    user, pw->pw_name);
639 		pw = NULL;
640 	}
641 #endif
642 	if (pw == NULL) {
643 		logit("Invalid user %.100s from %.100s",
644 		    user, get_remote_ipaddr());
645 #ifdef CUSTOM_FAILED_LOGIN
646 		record_failed_login(user,
647 		    get_canonical_hostname(options.use_dns), "ssh");
648 #endif
649 #ifdef SSH_AUDIT_EVENTS
650 		audit_event(SSH_INVALID_USER);
651 #endif /* SSH_AUDIT_EVENTS */
652 		return (NULL);
653 	}
654 	if (!allowed_user(pw))
655 		return (NULL);
656 #ifdef HAVE_LOGIN_CAP
657 	if ((lc = login_getpwclass(pw)) == NULL) {
658 		debug("unable to get login class: %s", user);
659 		return (NULL);
660 	}
661 #ifdef BSD_AUTH
662 	if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 ||
663 	    auth_approval(as, lc, pw->pw_name, "ssh") <= 0) {
664 		debug("Approval failure for %s", user);
665 		pw = NULL;
666 	}
667 	if (as != NULL)
668 		auth_close(as);
669 #endif
670 #endif
671 	if (pw != NULL)
672 		return (pwcopy(pw));
673 	return (NULL);
674 }
675 
676 /* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */
677 int
678 auth_key_is_revoked(Key *key)
679 {
680 	char *fp = NULL;
681 	int r;
682 
683 	if (options.revoked_keys_file == NULL)
684 		return 0;
685 	if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
686 	    SSH_FP_DEFAULT)) == NULL) {
687 		r = SSH_ERR_ALLOC_FAIL;
688 		error("%s: fingerprint key: %s", __func__, ssh_err(r));
689 		goto out;
690 	}
691 
692 	r = sshkey_check_revoked(key, options.revoked_keys_file);
693 	switch (r) {
694 	case 0:
695 		break; /* not revoked */
696 	case SSH_ERR_KEY_REVOKED:
697 		error("Authentication key %s %s revoked by file %s",
698 		    sshkey_type(key), fp, options.revoked_keys_file);
699 		goto out;
700 	default:
701 		error("Error checking authentication key %s %s in "
702 		    "revoked keys file %s: %s", sshkey_type(key), fp,
703 		    options.revoked_keys_file, ssh_err(r));
704 		goto out;
705 	}
706 
707 	/* Success */
708 	r = 0;
709 
710  out:
711 	free(fp);
712 	return r == 0 ? 0 : 1;
713 }
714 
715 void
716 auth_debug_add(const char *fmt,...)
717 {
718 	char buf[1024];
719 	va_list args;
720 
721 	if (!auth_debug_init)
722 		return;
723 
724 	va_start(args, fmt);
725 	vsnprintf(buf, sizeof(buf), fmt, args);
726 	va_end(args);
727 	buffer_put_cstring(&auth_debug, buf);
728 }
729 
730 void
731 auth_debug_send(void)
732 {
733 	char *msg;
734 
735 	if (!auth_debug_init)
736 		return;
737 	while (buffer_len(&auth_debug)) {
738 		msg = buffer_get_string(&auth_debug, NULL);
739 		packet_send_debug("%s", msg);
740 		free(msg);
741 	}
742 }
743 
744 void
745 auth_debug_reset(void)
746 {
747 	if (auth_debug_init)
748 		buffer_clear(&auth_debug);
749 	else {
750 		buffer_init(&auth_debug);
751 		auth_debug_init = 1;
752 	}
753 }
754 
755 struct passwd *
756 fakepw(void)
757 {
758 	static struct passwd fake;
759 
760 	memset(&fake, 0, sizeof(fake));
761 	fake.pw_name = "NOUSER";
762 	fake.pw_passwd =
763 	    "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK";
764 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
765 	fake.pw_gecos = "NOUSER";
766 #endif
767 	fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid;
768 	fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid;
769 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
770 	fake.pw_class = "";
771 #endif
772 	fake.pw_dir = "/nonexist";
773 	fake.pw_shell = "/nonexist";
774 
775 	return (&fake);
776 }
777