xref: /netbsd-src/crypto/external/bsd/openssh/dist/auth.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: auth.c,v 1.8 2013/11/08 19:18:24 christos Exp $	*/
2 /* $OpenBSD: auth.c,v 1.103 2013/05/19 02:42:42 djm Exp $ */
3 /*
4  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "includes.h"
28 __RCSID("$NetBSD: auth.c,v 1.8 2013/11/08 19:18:24 christos Exp $");
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/param.h>
32 
33 #include <errno.h>
34 #include <fcntl.h>
35 #include <libgen.h>
36 #include <login_cap.h>
37 #include <paths.h>
38 #include <pwd.h>
39 #include <stdarg.h>
40 #include <stdio.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "xmalloc.h"
45 #include "match.h"
46 #include "groupaccess.h"
47 #include "log.h"
48 #include "buffer.h"
49 #include "servconf.h"
50 #include "key.h"
51 #include "hostfile.h"
52 #include "auth.h"
53 #include "auth-options.h"
54 #include "canohost.h"
55 #include "uidswap.h"
56 #include "misc.h"
57 #include "packet.h"
58 #ifdef GSSAPI
59 #include "ssh-gss.h"
60 #endif
61 #include "authfile.h"
62 #include "monitor_wrap.h"
63 #include "krl.h"
64 #include "compat.h"
65 
66 #ifdef HAVE_LOGIN_CAP
67 #include <login_cap.h>
68 #endif
69 
70 /* import */
71 extern ServerOptions options;
72 extern int use_privsep;
73 
74 /* Debugging messages */
75 Buffer auth_debug;
76 int auth_debug_init;
77 
78 /*
79  * Check if the user is allowed to log in via ssh. If user is listed
80  * in DenyUsers or one of user's groups is listed in DenyGroups, false
81  * will be returned. If AllowUsers isn't empty and user isn't listed
82  * there, or if AllowGroups isn't empty and one of user's groups isn't
83  * listed there, false will be returned.
84  * If the user's shell is not executable, false will be returned.
85  * Otherwise true is returned.
86  */
87 int
88 allowed_user(struct passwd * pw)
89 {
90 #ifdef HAVE_LOGIN_CAP
91 	extern login_cap_t *lc;
92 	int match_name, match_ip;
93 	char *cap_hlist, *hp;
94 #endif
95 	struct stat st;
96 	const char *hostname = NULL, *ipaddr = NULL;
97 	u_int i;
98 
99 	/* Shouldn't be called if pw is NULL, but better safe than sorry... */
100 	if (!pw || !pw->pw_name)
101 		return 0;
102 
103 #ifdef HAVE_LOGIN_CAP
104 	hostname = get_canonical_hostname(1);
105 	ipaddr = get_remote_ipaddr();
106 
107 	lc = login_getclass(pw->pw_class);
108 
109 	/*
110 	 * Check the deny list.
111 	 */
112 	cap_hlist = login_getcapstr(lc, "host.deny", NULL, NULL);
113 	if (cap_hlist != NULL) {
114 		hp = strtok(cap_hlist, ",");
115 		while (hp != NULL) {
116 			match_name = match_hostname(hostname,
117 			    hp, strlen(hp));
118 			match_ip = match_hostname(ipaddr,
119 			    hp, strlen(hp));
120 			/*
121 			 * Only a positive match here causes a "deny".
122 			 */
123 			if (match_name > 0 || match_ip > 0) {
124 				free(cap_hlist);
125 				login_close(lc);
126 				return 0;
127 			}
128 			hp = strtok(NULL, ",");
129 		}
130 		free(cap_hlist);
131 	}
132 
133 	/*
134 	 * Check the allow list.  If the allow list exists, and the
135 	 * remote host is not in it, the user is implicitly denied.
136 	 */
137 	cap_hlist = login_getcapstr(lc, "host.allow", NULL, NULL);
138 	if (cap_hlist != NULL) {
139 		hp = strtok(cap_hlist, ",");
140 		if (hp == NULL) {
141 			/* Just in case there's an empty string... */
142 			free(cap_hlist);
143 			login_close(lc);
144 			return 0;
145 		}
146 		while (hp != NULL) {
147 			match_name = match_hostname(hostname,
148 			    hp, strlen(hp));
149 			match_ip = match_hostname(ipaddr,
150 			    hp, strlen(hp));
151 			/*
152 			 * Negative match causes an immediate "deny".
153 			 * Positive match causes us to break out
154 			 * of the loop (allowing a fallthrough).
155 			 */
156 			if (match_name < 0 || match_ip < 0) {
157 				free(cap_hlist);
158 				login_close(lc);
159 				return 0;
160 			}
161 			if (match_name > 0 || match_ip > 0)
162 				break;
163 			hp = strtok(NULL, ",");
164 		}
165 		free(cap_hlist);
166 		if (hp == NULL) {
167 			login_close(lc);
168 			return 0;
169 		}
170 	}
171 
172 	login_close(lc);
173 #endif
174 
175 #ifdef USE_PAM
176 	if (!options.use_pam) {
177 #endif
178 	/*
179 	 * password/account expiration.
180 	 */
181 	if (pw->pw_change || pw->pw_expire) {
182 		struct timeval tv;
183 
184 		(void)gettimeofday(&tv, (struct timezone *)NULL);
185 		if (pw->pw_expire) {
186 			if (tv.tv_sec >= pw->pw_expire) {
187 				logit("User %.100s not allowed because account has expired",
188 				    pw->pw_name);
189 				return 0;	/* expired */
190 			}
191 		}
192 #ifdef _PASSWORD_CHGNOW
193 		if (pw->pw_change == _PASSWORD_CHGNOW) {
194 			logit("User %.100s not allowed because password needs to be changed",
195 			    pw->pw_name);
196 
197 			return 0;	/* can't force password change (yet) */
198 		}
199 #endif
200 		if (pw->pw_change) {
201 			if (tv.tv_sec >= pw->pw_change) {
202 				logit("User %.100s not allowed because password has expired",
203 				    pw->pw_name);
204 				return 0;	/* expired */
205 			}
206 		}
207 	}
208 #ifdef USE_PAM
209 	}
210 #endif
211 
212 	/*
213 	 * Deny if shell does not exist or is not executable unless we
214 	 * are chrooting.
215 	 */
216 	/*
217 	 * XXX Should check to see if it is executable by the
218 	 * XXX requesting user.  --thorpej
219 	 */
220 	if (options.chroot_directory == NULL ||
221 	    strcasecmp(options.chroot_directory, "none") == 0) {
222 		char *shell = xstrdup((pw->pw_shell[0] == '\0') ?
223 		    _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */
224 
225 		if (stat(shell, &st) != 0) {
226 			logit("User %.100s not allowed because shell %.100s "
227 			    "does not exist", pw->pw_name, shell);
228 			free(shell);
229 			return 0;
230 		}
231 		if (S_ISREG(st.st_mode) == 0 ||
232 		    (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) {
233 			logit("User %.100s not allowed because shell %.100s "
234 			    "is not executable", pw->pw_name, shell);
235 			free(shell);
236 			return 0;
237 		}
238 		free(shell);
239 	}
240 	/*
241 	 * XXX Consider nuking {Allow,Deny}{Users,Groups}.  We have the
242 	 * XXX login_cap(3) mechanism which covers all other types of
243 	 * XXX logins, too.
244 	 */
245 
246 	if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
247 	    options.num_deny_groups > 0 || options.num_allow_groups > 0) {
248 		hostname = get_canonical_hostname(options.use_dns);
249 		ipaddr = get_remote_ipaddr();
250 	}
251 
252 	/* Return false if user is listed in DenyUsers */
253 	if (options.num_deny_users > 0) {
254 		for (i = 0; i < options.num_deny_users; i++)
255 			if (match_user(pw->pw_name, hostname, ipaddr,
256 			    options.deny_users[i])) {
257 				logit("User %.100s from %.100s not allowed "
258 				    "because listed in DenyUsers",
259 				    pw->pw_name, hostname);
260 				return 0;
261 			}
262 	}
263 	/* Return false if AllowUsers isn't empty and user isn't listed there */
264 	if (options.num_allow_users > 0) {
265 		for (i = 0; i < options.num_allow_users; i++)
266 			if (match_user(pw->pw_name, hostname, ipaddr,
267 			    options.allow_users[i]))
268 				break;
269 		/* i < options.num_allow_users iff we break for loop */
270 		if (i >= options.num_allow_users) {
271 			logit("User %.100s from %.100s not allowed because "
272 			    "not listed in AllowUsers", pw->pw_name, hostname);
273 			return 0;
274 		}
275 	}
276 	if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
277 		/* Get the user's group access list (primary and supplementary) */
278 		if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
279 			logit("User %.100s from %.100s not allowed because "
280 			    "not in any group", pw->pw_name, hostname);
281 			return 0;
282 		}
283 
284 		/* Return false if one of user's groups is listed in DenyGroups */
285 		if (options.num_deny_groups > 0)
286 			if (ga_match(options.deny_groups,
287 			    options.num_deny_groups)) {
288 				ga_free();
289 				logit("User %.100s from %.100s not allowed "
290 				    "because a group is listed in DenyGroups",
291 				    pw->pw_name, hostname);
292 				return 0;
293 			}
294 		/*
295 		 * Return false if AllowGroups isn't empty and one of user's groups
296 		 * isn't listed there
297 		 */
298 		if (options.num_allow_groups > 0)
299 			if (!ga_match(options.allow_groups,
300 			    options.num_allow_groups)) {
301 				ga_free();
302 				logit("User %.100s from %.100s not allowed "
303 				    "because none of user's groups are listed "
304 				    "in AllowGroups", pw->pw_name, hostname);
305 				return 0;
306 			}
307 		ga_free();
308 	}
309 	/* We found no reason not to let this user try to log on... */
310 	return 1;
311 }
312 
313 void
314 auth_info(Authctxt *authctxt, const char *fmt, ...)
315 {
316 	va_list ap;
317         int i;
318 
319 	free(authctxt->info);
320 	authctxt->info = NULL;
321 
322 	va_start(ap, fmt);
323 	i = vasprintf(&authctxt->info, fmt, ap);
324 	va_end(ap);
325 
326 	if (i < 0 || authctxt->info == NULL)
327 		fatal("vasprintf failed");
328 }
329 
330 void
331 auth_log(Authctxt *authctxt, int authenticated, int partial,
332     const char *method, const char *submethod)
333 {
334 	void (*authlog) (const char *fmt,...) = verbose;
335 	const char *authmsg;
336 
337 	if (use_privsep && !mm_is_monitor() && !authctxt->postponed)
338 		return;
339 
340 	/* Raise logging level */
341 	if (authenticated == 1 ||
342 	    !authctxt->valid ||
343 	    authctxt->failures >= options.max_authtries / 2 ||
344 	    strcmp(method, "password") == 0)
345 		authlog = logit;
346 
347 	if (authctxt->postponed)
348 		authmsg = "Postponed";
349 	else if (partial)
350 		authmsg = "Partial";
351 	else
352 		authmsg = authenticated ? "Accepted" : "Failed";
353 
354 	authlog("%s %s%s%s for %s%.100s from %.200s port %d %s%s%s",
355 	    authmsg,
356 	    method,
357 	    submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod,
358 	    authctxt->valid ? "" : "invalid user ",
359 	    authctxt->user,
360 	    get_remote_ipaddr(),
361 	    get_remote_port(),
362 	    compat20 ? "ssh2" : "ssh1",
363 	    authctxt->info != NULL ? ": " : "",
364 	    authctxt->info != NULL ? authctxt->info : "");
365 	free(authctxt->info);
366 	authctxt->info = NULL;
367 }
368 
369 /*
370  * Check whether root logins are disallowed.
371  */
372 int
373 auth_root_allowed(const char *method)
374 {
375 	switch (options.permit_root_login) {
376 	case PERMIT_YES:
377 		return 1;
378 	case PERMIT_NO_PASSWD:
379 		if (strcmp(method, "password") != 0)
380 			return 1;
381 		break;
382 	case PERMIT_FORCED_ONLY:
383 		if (forced_command) {
384 			logit("Root login accepted for forced command.");
385 			return 1;
386 		}
387 		break;
388 	}
389 	logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
390 	return 0;
391 }
392 
393 
394 /*
395  * Given a template and a passwd structure, build a filename
396  * by substituting % tokenised options. Currently, %% becomes '%',
397  * %h becomes the home directory and %u the username.
398  *
399  * This returns a buffer allocated by xmalloc.
400  */
401 char *
402 expand_authorized_keys(const char *filename, struct passwd *pw)
403 {
404 	char *file, ret[MAXPATHLEN];
405 	int i;
406 
407 	file = percent_expand(filename, "h", pw->pw_dir,
408 	    "u", pw->pw_name, (char *)NULL);
409 
410 	/*
411 	 * Ensure that filename starts anchored. If not, be backward
412 	 * compatible and prepend the '%h/'
413 	 */
414 	if (*file == '/')
415 		return (file);
416 
417 	i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file);
418 	if (i < 0 || (size_t)i >= sizeof(ret))
419 		fatal("expand_authorized_keys: path too long");
420 	free(file);
421 	return (xstrdup(ret));
422 }
423 
424 char *
425 authorized_principals_file(struct passwd *pw)
426 {
427 	if (options.authorized_principals_file == NULL ||
428 	    strcasecmp(options.authorized_principals_file, "none") == 0)
429 		return NULL;
430 	return expand_authorized_keys(options.authorized_principals_file, pw);
431 }
432 
433 /* return ok if key exists in sysfile or userfile */
434 HostStatus
435 check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
436     const char *sysfile, const char *userfile)
437 {
438 	char *user_hostfile;
439 	struct stat st;
440 	HostStatus host_status;
441 	struct hostkeys *hostkeys;
442 	const struct hostkey_entry *found;
443 
444 	hostkeys = init_hostkeys();
445 	load_hostkeys(hostkeys, host, sysfile);
446 	if (userfile != NULL) {
447 		user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
448 		if (options.strict_modes &&
449 		    (stat(user_hostfile, &st) == 0) &&
450 		    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
451 		    (st.st_mode & 022) != 0)) {
452 			logit("Authentication refused for %.100s: "
453 			    "bad owner or modes for %.200s",
454 			    pw->pw_name, user_hostfile);
455 			auth_debug_add("Ignored %.200s: bad ownership or modes",
456 			    user_hostfile);
457 		} else {
458 			temporarily_use_uid(pw);
459 			load_hostkeys(hostkeys, host, user_hostfile);
460 			restore_uid();
461 		}
462 		free(user_hostfile);
463 	}
464 	host_status = check_key_in_hostkeys(hostkeys, key, &found);
465 	if (host_status == HOST_REVOKED)
466 		error("WARNING: revoked key for %s attempted authentication",
467 		    found->host);
468 	else if (host_status == HOST_OK)
469 		debug("%s: key for %s found at %s:%ld", __func__,
470 		    found->host, found->file, found->line);
471 	else
472 		debug("%s: key for host %s not found", __func__, host);
473 
474 	free_hostkeys(hostkeys);
475 
476 	return host_status;
477 }
478 
479 /*
480  * Check a given path for security. This is defined as all components
481  * of the path to the file must be owned by either the owner of
482  * of the file or root and no directories must be group or world writable.
483  *
484  * XXX Should any specific check be done for sym links ?
485  *
486  * Takes a file name, its stat information (preferably from fstat() to
487  * avoid races), the uid of the expected owner, their home directory and an
488  * error buffer plus max size as arguments.
489  *
490  * Returns 0 on success and -1 on failure
491  */
492 int
493 auth_secure_path(const char *name, struct stat *stp, const char *pw_dir,
494     uid_t uid, char *err, size_t errlen)
495 {
496 	char buf[MAXPATHLEN], homedir[MAXPATHLEN];
497 	char *cp;
498 	int comparehome = 0;
499 	struct stat st;
500 
501 	if (realpath(name, buf) == NULL) {
502 		snprintf(err, errlen, "realpath %s failed: %s", name,
503 		    strerror(errno));
504 		return -1;
505 	}
506 	if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
507 		comparehome = 1;
508 
509 	if (!S_ISREG(stp->st_mode)) {
510 		snprintf(err, errlen, "%s is not a regular file", buf);
511 		return -1;
512 	}
513 	if ((stp->st_uid != 0 && stp->st_uid != uid) ||
514 	    (stp->st_mode & 022) != 0) {
515 		snprintf(err, errlen, "bad ownership or modes for file %s",
516 		    buf);
517 		return -1;
518 	}
519 
520 	/* for each component of the canonical path, walking upwards */
521 	for (;;) {
522 		if ((cp = dirname(buf)) == NULL) {
523 			snprintf(err, errlen, "dirname() failed");
524 			return -1;
525 		}
526 		strlcpy(buf, cp, sizeof(buf));
527 
528 		if (stat(buf, &st) < 0 ||
529 		    (st.st_uid != 0 && st.st_uid != uid) ||
530 		    (st.st_mode & 022) != 0) {
531 			snprintf(err, errlen,
532 			    "bad ownership or modes for directory %s", buf);
533 			return -1;
534 		}
535 
536 		/* If are past the homedir then we can stop */
537 		if (comparehome && strcmp(homedir, buf) == 0)
538 			break;
539 
540 		/*
541 		 * dirname should always complete with a "/" path,
542 		 * but we can be paranoid and check for "." too
543 		 */
544 		if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
545 			break;
546 	}
547 	return 0;
548 }
549 
550 /*
551  * Version of secure_path() that accepts an open file descriptor to
552  * avoid races.
553  *
554  * Returns 0 on success and -1 on failure
555  */
556 static int
557 secure_filename(FILE *f, const char *file, struct passwd *pw,
558     char *err, size_t errlen)
559 {
560 	struct stat st;
561 
562 	/* check the open file to avoid races */
563 	if (fstat(fileno(f), &st) < 0) {
564 		snprintf(err, errlen, "cannot stat file %s: %s",
565 		    file, strerror(errno));
566 		return -1;
567 	}
568 	return auth_secure_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
569 }
570 
571 static FILE *
572 auth_openfile(const char *file, struct passwd *pw, int strict_modes,
573     int log_missing, const char *file_type)
574 {
575 	char line[1024];
576 	struct stat st;
577 	int fd;
578 	FILE *f;
579 
580 	if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) {
581 		if (log_missing || errno != ENOENT)
582 			debug("Could not open %s '%s': %s", file_type, file,
583 			   strerror(errno));
584 		return NULL;
585 	}
586 
587 	if (fstat(fd, &st) < 0) {
588 		close(fd);
589 		return NULL;
590 	}
591 	if (!S_ISREG(st.st_mode)) {
592 		logit("User %s %s %s is not a regular file",
593 		    pw->pw_name, file_type, file);
594 		close(fd);
595 		return NULL;
596 	}
597 	unset_nonblock(fd);
598 	if ((f = fdopen(fd, "r")) == NULL) {
599 		close(fd);
600 		return NULL;
601 	}
602 	if (strict_modes &&
603 	    secure_filename(f, file, pw, line, sizeof(line)) != 0) {
604 		fclose(f);
605 		logit("Authentication refused: %s", line);
606 		auth_debug_add("Ignored %s: %s", file_type, line);
607 		return NULL;
608 	}
609 
610 	return f;
611 }
612 
613 
614 FILE *
615 auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes)
616 {
617 	return auth_openfile(file, pw, strict_modes, 1, "authorized keys");
618 }
619 
620 FILE *
621 auth_openprincipals(const char *file, struct passwd *pw, int strict_modes)
622 {
623 	return auth_openfile(file, pw, strict_modes, 0,
624 	    "authorized principals");
625 }
626 
627 struct passwd *
628 getpwnamallow(const char *user)
629 {
630 #ifdef HAVE_LOGIN_CAP
631  	extern login_cap_t *lc;
632 #ifdef BSD_AUTH
633  	auth_session_t *as;
634 #endif
635 #endif
636 	struct passwd *pw;
637 	struct connection_info *ci = get_connection_info(1, options.use_dns);
638 
639 	ci->user = user;
640 	parse_server_match_config(&options, ci);
641 
642 	pw = getpwnam(user);
643 	if (pw == NULL) {
644 		logit("Invalid user %.100s from %.100s",
645 		    user, get_remote_ipaddr());
646 		return (NULL);
647 	}
648 	if (!allowed_user(pw))
649 		return (NULL);
650 #ifdef HAVE_LOGIN_CAP
651 	if ((lc = login_getclass(pw->pw_class)) == NULL) {
652 		debug("unable to get login class: %s", user);
653 		return (NULL);
654 	}
655 #ifdef BSD_AUTH
656 	if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 ||
657 	    auth_approval(as, lc, pw->pw_name, "ssh") <= 0) {
658 		debug("Approval failure for %s", user);
659 		pw = NULL;
660 	}
661 	if (as != NULL)
662 		auth_close(as);
663 #endif
664 #endif
665 	if (pw != NULL)
666 		return (pwcopy(pw));
667 	return (NULL);
668 }
669 
670 /* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */
671 int
672 auth_key_is_revoked(Key *key)
673 {
674 	char *key_fp;
675 
676 	if (options.revoked_keys_file == NULL)
677 		return 0;
678 	switch (ssh_krl_file_contains_key(options.revoked_keys_file, key)) {
679 	case 0:
680 		return 0;	/* Not revoked */
681 	case -2:
682 		break;		/* Not a KRL */
683 	default:
684 		goto revoked;
685 	}
686 	debug3("%s: treating %s as a key list", __func__,
687 	    options.revoked_keys_file);
688 	switch (key_in_file(key, options.revoked_keys_file, 0)) {
689 	case 0:
690 		/* key not revoked */
691 		return 0;
692 	case -1:
693 		/* Error opening revoked_keys_file: refuse all keys */
694 		error("Revoked keys file is unreadable: refusing public key "
695 		    "authentication");
696 		return 1;
697 	case 1:
698  revoked:
699 		/* Key revoked */
700 		key_fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
701 		error("WARNING: authentication attempt with a revoked "
702 		    "%s key %s ", key_type(key), key_fp);
703 		free(key_fp);
704 		return 1;
705 	}
706 	fatal("key_in_file returned junk");
707 }
708 
709 void
710 auth_debug_add(const char *fmt,...)
711 {
712 	char buf[1024];
713 	va_list args;
714 
715 	if (!auth_debug_init)
716 		return;
717 
718 	va_start(args, fmt);
719 	vsnprintf(buf, sizeof(buf), fmt, args);
720 	va_end(args);
721 	buffer_put_cstring(&auth_debug, buf);
722 }
723 
724 void
725 auth_debug_send(void)
726 {
727 	char *msg;
728 
729 	if (!auth_debug_init)
730 		return;
731 	while (buffer_len(&auth_debug)) {
732 		msg = buffer_get_string(&auth_debug, NULL);
733 		packet_send_debug("%s", msg);
734 		free(msg);
735 	}
736 }
737 
738 void
739 auth_debug_reset(void)
740 {
741 	if (auth_debug_init)
742 		buffer_clear(&auth_debug);
743 	else {
744 		buffer_init(&auth_debug);
745 		auth_debug_init = 1;
746 	}
747 }
748 
749 struct passwd *
750 fakepw(void)
751 {
752 	static struct passwd fake;
753 	static char nouser[] = "NOUSER";
754 	static char nonexist[] = "/nonexist";
755 
756 	memset(&fake, 0, sizeof(fake));
757 	fake.pw_name = nouser;
758 	fake.pw_passwd = __UNCONST(
759 	    "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK");
760 	fake.pw_gecos = nouser;
761 	fake.pw_uid = (uid_t)-1;
762 	fake.pw_gid = (gid_t)-1;
763 	fake.pw_class = __UNCONST("");
764 	fake.pw_dir = nonexist;
765 	fake.pw_shell = nonexist;
766 
767 	return (&fake);
768 }
769