xref: /freebsd/crypto/openssh/auth.c (revision 595e514d0df2bac5b813d35f83e32875dbf16a83)
1 /* $OpenBSD: auth.c,v 1.101 2013/02/06 00:22:21 dtucker 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 #include <sys/param.h>
32 
33 #include <netinet/in.h>
34 
35 #include <errno.h>
36 #include <fcntl.h>
37 #ifdef HAVE_PATHS_H
38 # include <paths.h>
39 #endif
40 #include <pwd.h>
41 #ifdef HAVE_LOGIN_H
42 #include <login.h>
43 #endif
44 #ifdef USE_SHADOW
45 #include <shadow.h>
46 #endif
47 #ifdef HAVE_LIBGEN_H
48 #include <libgen.h>
49 #endif
50 #include <stdarg.h>
51 #include <stdio.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include "xmalloc.h"
56 #include "match.h"
57 #include "groupaccess.h"
58 #include "log.h"
59 #include "buffer.h"
60 #include "servconf.h"
61 #include "key.h"
62 #include "hostfile.h"
63 #include "auth.h"
64 #include "auth-options.h"
65 #include "canohost.h"
66 #include "uidswap.h"
67 #include "misc.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 "krl.h"
76 
77 /* import */
78 extern ServerOptions options;
79 extern int use_privsep;
80 extern Buffer loginmsg;
81 extern struct passwd *privsep_pw;
82 
83 /* Debugging messages */
84 Buffer auth_debug;
85 int auth_debug_init;
86 
87 /*
88  * Check if the user is allowed to log in via ssh. If user is listed
89  * in DenyUsers or one of user's groups is listed in DenyGroups, false
90  * will be returned. If AllowUsers isn't empty and user isn't listed
91  * there, or if AllowGroups isn't empty and one of user's groups isn't
92  * listed there, false will be returned.
93  * If the user's shell is not executable, false will be returned.
94  * Otherwise true is returned.
95  */
96 int
97 allowed_user(struct passwd * pw)
98 {
99 	struct stat st;
100 	const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
101 	u_int i;
102 #ifdef USE_SHADOW
103 	struct spwd *spw = NULL;
104 #endif
105 
106 	/* Shouldn't be called if pw is NULL, but better safe than sorry... */
107 	if (!pw || !pw->pw_name)
108 		return 0;
109 
110 #ifdef USE_SHADOW
111 	if (!options.use_pam)
112 		spw = getspnam(pw->pw_name);
113 #ifdef HAS_SHADOW_EXPIRE
114 	if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw))
115 		return 0;
116 #endif /* HAS_SHADOW_EXPIRE */
117 #endif /* USE_SHADOW */
118 
119 	/* grab passwd field for locked account check */
120 	passwd = pw->pw_passwd;
121 #ifdef USE_SHADOW
122 	if (spw != NULL)
123 #ifdef USE_LIBIAF
124 		passwd = get_iaf_password(pw);
125 #else
126 		passwd = spw->sp_pwdp;
127 #endif /* USE_LIBIAF */
128 #endif
129 
130 	/* check for locked account */
131 	if (!options.use_pam && passwd && *passwd) {
132 		int locked = 0;
133 
134 #ifdef LOCKED_PASSWD_STRING
135 		if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0)
136 			 locked = 1;
137 #endif
138 #ifdef LOCKED_PASSWD_PREFIX
139 		if (strncmp(passwd, LOCKED_PASSWD_PREFIX,
140 		    strlen(LOCKED_PASSWD_PREFIX)) == 0)
141 			 locked = 1;
142 #endif
143 #ifdef LOCKED_PASSWD_SUBSTR
144 		if (strstr(passwd, LOCKED_PASSWD_SUBSTR))
145 			locked = 1;
146 #endif
147 #ifdef USE_LIBIAF
148 		free((void *) passwd);
149 #endif /* USE_LIBIAF */
150 		if (locked) {
151 			logit("User %.100s not allowed because account is locked",
152 			    pw->pw_name);
153 			return 0;
154 		}
155 	}
156 
157 	/*
158 	 * Deny if shell does not exist or is not executable unless we
159 	 * are chrooting.
160 	 */
161 	if (options.chroot_directory == NULL ||
162 	    strcasecmp(options.chroot_directory, "none") == 0) {
163 		char *shell = xstrdup((pw->pw_shell[0] == '\0') ?
164 		    _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */
165 
166 		if (stat(shell, &st) != 0) {
167 			logit("User %.100s not allowed because shell %.100s "
168 			    "does not exist", pw->pw_name, shell);
169 			xfree(shell);
170 			return 0;
171 		}
172 		if (S_ISREG(st.st_mode) == 0 ||
173 		    (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) {
174 			logit("User %.100s not allowed because shell %.100s "
175 			    "is not executable", pw->pw_name, shell);
176 			xfree(shell);
177 			return 0;
178 		}
179 		xfree(shell);
180 	}
181 
182 	if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
183 	    options.num_deny_groups > 0 || options.num_allow_groups > 0) {
184 		hostname = get_canonical_hostname(options.use_dns);
185 		ipaddr = get_remote_ipaddr();
186 	}
187 
188 	/* Return false if user is listed in DenyUsers */
189 	if (options.num_deny_users > 0) {
190 		for (i = 0; i < options.num_deny_users; i++)
191 			if (match_user(pw->pw_name, hostname, ipaddr,
192 			    options.deny_users[i])) {
193 				logit("User %.100s from %.100s not allowed "
194 				    "because listed in DenyUsers",
195 				    pw->pw_name, hostname);
196 				return 0;
197 			}
198 	}
199 	/* Return false if AllowUsers isn't empty and user isn't listed there */
200 	if (options.num_allow_users > 0) {
201 		for (i = 0; i < options.num_allow_users; i++)
202 			if (match_user(pw->pw_name, hostname, ipaddr,
203 			    options.allow_users[i]))
204 				break;
205 		/* i < options.num_allow_users iff we break for loop */
206 		if (i >= options.num_allow_users) {
207 			logit("User %.100s from %.100s not allowed because "
208 			    "not listed in AllowUsers", pw->pw_name, hostname);
209 			return 0;
210 		}
211 	}
212 	if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
213 		/* Get the user's group access list (primary and supplementary) */
214 		if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
215 			logit("User %.100s from %.100s not allowed because "
216 			    "not in any group", pw->pw_name, hostname);
217 			return 0;
218 		}
219 
220 		/* Return false if one of user's groups is listed in DenyGroups */
221 		if (options.num_deny_groups > 0)
222 			if (ga_match(options.deny_groups,
223 			    options.num_deny_groups)) {
224 				ga_free();
225 				logit("User %.100s from %.100s not allowed "
226 				    "because a group is listed in DenyGroups",
227 				    pw->pw_name, hostname);
228 				return 0;
229 			}
230 		/*
231 		 * Return false if AllowGroups isn't empty and one of user's groups
232 		 * isn't listed there
233 		 */
234 		if (options.num_allow_groups > 0)
235 			if (!ga_match(options.allow_groups,
236 			    options.num_allow_groups)) {
237 				ga_free();
238 				logit("User %.100s from %.100s not allowed "
239 				    "because none of user's groups are listed "
240 				    "in AllowGroups", pw->pw_name, hostname);
241 				return 0;
242 			}
243 		ga_free();
244 	}
245 
246 #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER
247 	if (!sys_auth_allowed_user(pw, &loginmsg))
248 		return 0;
249 #endif
250 
251 	/* We found no reason not to let this user try to log on... */
252 	return 1;
253 }
254 
255 void
256 auth_log(Authctxt *authctxt, int authenticated, int partial,
257     const char *method, const char *submethod, const char *info)
258 {
259 	void (*authlog) (const char *fmt,...) = verbose;
260 	char *authmsg;
261 
262 	if (use_privsep && !mm_is_monitor() && !authctxt->postponed)
263 		return;
264 
265 	/* Raise logging level */
266 	if (authenticated == 1 ||
267 	    !authctxt->valid ||
268 	    authctxt->failures >= options.max_authtries / 2 ||
269 	    strcmp(method, "password") == 0)
270 		authlog = logit;
271 
272 	if (authctxt->postponed)
273 		authmsg = "Postponed";
274 	else if (partial)
275 		authmsg = "Partial";
276 	else
277 		authmsg = authenticated ? "Accepted" : "Failed";
278 
279 	authlog("%s %s%s%s for %s%.100s from %.200s port %d%s",
280 	    authmsg,
281 	    method,
282 	    submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod,
283 	    authctxt->valid ? "" : "invalid user ",
284 	    authctxt->user,
285 	    get_remote_ipaddr(),
286 	    get_remote_port(),
287 	    info);
288 
289 #ifdef CUSTOM_FAILED_LOGIN
290 	if (authenticated == 0 && !authctxt->postponed &&
291 	    (strcmp(method, "password") == 0 ||
292 	    strncmp(method, "keyboard-interactive", 20) == 0 ||
293 	    strcmp(method, "challenge-response") == 0))
294 		record_failed_login(authctxt->user,
295 		    get_canonical_hostname(options.use_dns), "ssh");
296 # ifdef WITH_AIXAUTHENTICATE
297 	if (authenticated)
298 		sys_auth_record_login(authctxt->user,
299 		    get_canonical_hostname(options.use_dns), "ssh", &loginmsg);
300 # endif
301 #endif
302 #ifdef SSH_AUDIT_EVENTS
303 	if (authenticated == 0 && !authctxt->postponed)
304 		audit_event(audit_classify_auth(method));
305 #endif
306 }
307 
308 /*
309  * Check whether root logins are disallowed.
310  */
311 int
312 auth_root_allowed(const char *method)
313 {
314 	switch (options.permit_root_login) {
315 	case PERMIT_YES:
316 		return 1;
317 	case PERMIT_NO_PASSWD:
318 		if (strcmp(method, "password") != 0)
319 			return 1;
320 		break;
321 	case PERMIT_FORCED_ONLY:
322 		if (forced_command) {
323 			logit("Root login accepted for forced command.");
324 			return 1;
325 		}
326 		break;
327 	}
328 	logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
329 	return 0;
330 }
331 
332 
333 /*
334  * Given a template and a passwd structure, build a filename
335  * by substituting % tokenised options. Currently, %% becomes '%',
336  * %h becomes the home directory and %u the username.
337  *
338  * This returns a buffer allocated by xmalloc.
339  */
340 char *
341 expand_authorized_keys(const char *filename, struct passwd *pw)
342 {
343 	char *file, ret[MAXPATHLEN];
344 	int i;
345 
346 	file = percent_expand(filename, "h", pw->pw_dir,
347 	    "u", pw->pw_name, (char *)NULL);
348 
349 	/*
350 	 * Ensure that filename starts anchored. If not, be backward
351 	 * compatible and prepend the '%h/'
352 	 */
353 	if (*file == '/')
354 		return (file);
355 
356 	i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file);
357 	if (i < 0 || (size_t)i >= sizeof(ret))
358 		fatal("expand_authorized_keys: path too long");
359 	xfree(file);
360 	return (xstrdup(ret));
361 }
362 
363 char *
364 authorized_principals_file(struct passwd *pw)
365 {
366 	if (options.authorized_principals_file == NULL ||
367 	    strcasecmp(options.authorized_principals_file, "none") == 0)
368 		return NULL;
369 	return expand_authorized_keys(options.authorized_principals_file, pw);
370 }
371 
372 /* return ok if key exists in sysfile or userfile */
373 HostStatus
374 check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
375     const char *sysfile, const char *userfile)
376 {
377 	char *user_hostfile;
378 	struct stat st;
379 	HostStatus host_status;
380 	struct hostkeys *hostkeys;
381 	const struct hostkey_entry *found;
382 
383 	hostkeys = init_hostkeys();
384 	load_hostkeys(hostkeys, host, sysfile);
385 	if (userfile != NULL) {
386 		user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
387 		if (options.strict_modes &&
388 		    (stat(user_hostfile, &st) == 0) &&
389 		    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
390 		    (st.st_mode & 022) != 0)) {
391 			logit("Authentication refused for %.100s: "
392 			    "bad owner or modes for %.200s",
393 			    pw->pw_name, user_hostfile);
394 			auth_debug_add("Ignored %.200s: bad ownership or modes",
395 			    user_hostfile);
396 		} else {
397 			temporarily_use_uid(pw);
398 			load_hostkeys(hostkeys, host, user_hostfile);
399 			restore_uid();
400 		}
401 		xfree(user_hostfile);
402 	}
403 	host_status = check_key_in_hostkeys(hostkeys, key, &found);
404 	if (host_status == HOST_REVOKED)
405 		error("WARNING: revoked key for %s attempted authentication",
406 		    found->host);
407 	else if (host_status == HOST_OK)
408 		debug("%s: key for %s found at %s:%ld", __func__,
409 		    found->host, found->file, found->line);
410 	else
411 		debug("%s: key for host %s not found", __func__, host);
412 
413 	free_hostkeys(hostkeys);
414 
415 	return host_status;
416 }
417 
418 /*
419  * Check a given path for security. This is defined as all components
420  * of the path to the file must be owned by either the owner of
421  * of the file or root and no directories must be group or world writable.
422  *
423  * XXX Should any specific check be done for sym links ?
424  *
425  * Takes a file name, its stat information (preferably from fstat() to
426  * avoid races), the uid of the expected owner, their home directory and an
427  * error buffer plus max size as arguments.
428  *
429  * Returns 0 on success and -1 on failure
430  */
431 int
432 auth_secure_path(const char *name, struct stat *stp, const char *pw_dir,
433     uid_t uid, char *err, size_t errlen)
434 {
435 	char buf[MAXPATHLEN], homedir[MAXPATHLEN];
436 	char *cp;
437 	int comparehome = 0;
438 	struct stat st;
439 
440 	if (realpath(name, buf) == NULL) {
441 		snprintf(err, errlen, "realpath %s failed: %s", name,
442 		    strerror(errno));
443 		return -1;
444 	}
445 	if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
446 		comparehome = 1;
447 
448 	if (!S_ISREG(stp->st_mode)) {
449 		snprintf(err, errlen, "%s is not a regular file", buf);
450 		return -1;
451 	}
452 	if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) ||
453 	    (stp->st_mode & 022) != 0) {
454 		snprintf(err, errlen, "bad ownership or modes for file %s",
455 		    buf);
456 		return -1;
457 	}
458 
459 	/* for each component of the canonical path, walking upwards */
460 	for (;;) {
461 		if ((cp = dirname(buf)) == NULL) {
462 			snprintf(err, errlen, "dirname() failed");
463 			return -1;
464 		}
465 		strlcpy(buf, cp, sizeof(buf));
466 
467 		if (stat(buf, &st) < 0 ||
468 		    (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) ||
469 		    (st.st_mode & 022) != 0) {
470 			snprintf(err, errlen,
471 			    "bad ownership or modes for directory %s", buf);
472 			return -1;
473 		}
474 
475 		/* If are past the homedir then we can stop */
476 		if (comparehome && strcmp(homedir, buf) == 0)
477 			break;
478 
479 		/*
480 		 * dirname should always complete with a "/" path,
481 		 * but we can be paranoid and check for "." too
482 		 */
483 		if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
484 			break;
485 	}
486 	return 0;
487 }
488 
489 /*
490  * Version of secure_path() that accepts an open file descriptor to
491  * avoid races.
492  *
493  * Returns 0 on success and -1 on failure
494  */
495 static int
496 secure_filename(FILE *f, const char *file, struct passwd *pw,
497     char *err, size_t errlen)
498 {
499 	struct stat st;
500 
501 	/* check the open file to avoid races */
502 	if (fstat(fileno(f), &st) < 0) {
503 		snprintf(err, errlen, "cannot stat file %s: %s",
504 		    file, strerror(errno));
505 		return -1;
506 	}
507 	return auth_secure_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
508 }
509 
510 static FILE *
511 auth_openfile(const char *file, struct passwd *pw, int strict_modes,
512     int log_missing, char *file_type)
513 {
514 	char line[1024];
515 	struct stat st;
516 	int fd;
517 	FILE *f;
518 
519 	if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) {
520 		if (log_missing || errno != ENOENT)
521 			debug("Could not open %s '%s': %s", file_type, file,
522 			   strerror(errno));
523 		return NULL;
524 	}
525 
526 	if (fstat(fd, &st) < 0) {
527 		close(fd);
528 		return NULL;
529 	}
530 	if (!S_ISREG(st.st_mode)) {
531 		logit("User %s %s %s is not a regular file",
532 		    pw->pw_name, file_type, file);
533 		close(fd);
534 		return NULL;
535 	}
536 	unset_nonblock(fd);
537 	if ((f = fdopen(fd, "r")) == NULL) {
538 		close(fd);
539 		return NULL;
540 	}
541 	if (strict_modes &&
542 	    secure_filename(f, file, pw, line, sizeof(line)) != 0) {
543 		fclose(f);
544 		logit("Authentication refused: %s", line);
545 		auth_debug_add("Ignored %s: %s", file_type, line);
546 		return NULL;
547 	}
548 
549 	return f;
550 }
551 
552 
553 FILE *
554 auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes)
555 {
556 	return auth_openfile(file, pw, strict_modes, 1, "authorized keys");
557 }
558 
559 FILE *
560 auth_openprincipals(const char *file, struct passwd *pw, int strict_modes)
561 {
562 	return auth_openfile(file, pw, strict_modes, 0,
563 	    "authorized principals");
564 }
565 
566 struct passwd *
567 getpwnamallow(const char *user)
568 {
569 #ifdef HAVE_LOGIN_CAP
570 	extern login_cap_t *lc;
571 #ifdef BSD_AUTH
572 	auth_session_t *as;
573 #endif
574 #endif
575 	struct passwd *pw;
576 	struct connection_info *ci = get_connection_info(1, options.use_dns);
577 
578 	ci->user = user;
579 	parse_server_match_config(&options, ci);
580 
581 #if defined(_AIX) && defined(HAVE_SETAUTHDB)
582 	aix_setauthdb(user);
583 #endif
584 
585 	pw = getpwnam(user);
586 
587 #if defined(_AIX) && defined(HAVE_SETAUTHDB)
588 	aix_restoreauthdb();
589 #endif
590 #ifdef HAVE_CYGWIN
591 	/*
592 	 * Windows usernames are case-insensitive.  To avoid later problems
593 	 * when trying to match the username, the user is only allowed to
594 	 * login if the username is given in the same case as stored in the
595 	 * user database.
596 	 */
597 	if (pw != NULL && strcmp(user, pw->pw_name) != 0) {
598 		logit("Login name %.100s does not match stored username %.100s",
599 		    user, pw->pw_name);
600 		pw = NULL;
601 	}
602 #endif
603 	if (pw == NULL) {
604 		logit("Invalid user %.100s from %.100s",
605 		    user, get_remote_ipaddr());
606 #ifdef CUSTOM_FAILED_LOGIN
607 		record_failed_login(user,
608 		    get_canonical_hostname(options.use_dns), "ssh");
609 #endif
610 #ifdef SSH_AUDIT_EVENTS
611 		audit_event(SSH_INVALID_USER);
612 #endif /* SSH_AUDIT_EVENTS */
613 		return (NULL);
614 	}
615 	if (!allowed_user(pw))
616 		return (NULL);
617 #ifdef HAVE_LOGIN_CAP
618 	if ((lc = login_getpwclass(pw)) == NULL) {
619 		debug("unable to get login class: %s", user);
620 		return (NULL);
621 	}
622 #ifdef BSD_AUTH
623 	if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 ||
624 	    auth_approval(as, lc, pw->pw_name, "ssh") <= 0) {
625 		debug("Approval failure for %s", user);
626 		pw = NULL;
627 	}
628 	if (as != NULL)
629 		auth_close(as);
630 #endif
631 #endif
632 	if (pw != NULL)
633 		return (pwcopy(pw));
634 	return (NULL);
635 }
636 
637 /* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */
638 int
639 auth_key_is_revoked(Key *key)
640 {
641 	char *key_fp;
642 
643 	if (options.revoked_keys_file == NULL)
644 		return 0;
645 	switch (ssh_krl_file_contains_key(options.revoked_keys_file, key)) {
646 	case 0:
647 		return 0;	/* Not revoked */
648 	case -2:
649 		break;		/* Not a KRL */
650 	default:
651 		goto revoked;
652 	}
653 	debug3("%s: treating %s as a key list", __func__,
654 	    options.revoked_keys_file);
655 	switch (key_in_file(key, options.revoked_keys_file, 0)) {
656 	case 0:
657 		/* key not revoked */
658 		return 0;
659 	case -1:
660 		/* Error opening revoked_keys_file: refuse all keys */
661 		error("Revoked keys file is unreadable: refusing public key "
662 		    "authentication");
663 		return 1;
664 	case 1:
665  revoked:
666 		/* Key revoked */
667 		key_fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
668 		error("WARNING: authentication attempt with a revoked "
669 		    "%s key %s ", key_type(key), key_fp);
670 		xfree(key_fp);
671 		return 1;
672 	}
673 	fatal("key_in_file returned junk");
674 }
675 
676 void
677 auth_debug_add(const char *fmt,...)
678 {
679 	char buf[1024];
680 	va_list args;
681 
682 	if (!auth_debug_init)
683 		return;
684 
685 	va_start(args, fmt);
686 	vsnprintf(buf, sizeof(buf), fmt, args);
687 	va_end(args);
688 	buffer_put_cstring(&auth_debug, buf);
689 }
690 
691 void
692 auth_debug_send(void)
693 {
694 	char *msg;
695 
696 	if (!auth_debug_init)
697 		return;
698 	while (buffer_len(&auth_debug)) {
699 		msg = buffer_get_string(&auth_debug, NULL);
700 		packet_send_debug("%s", msg);
701 		xfree(msg);
702 	}
703 }
704 
705 void
706 auth_debug_reset(void)
707 {
708 	if (auth_debug_init)
709 		buffer_clear(&auth_debug);
710 	else {
711 		buffer_init(&auth_debug);
712 		auth_debug_init = 1;
713 	}
714 }
715 
716 struct passwd *
717 fakepw(void)
718 {
719 	static struct passwd fake;
720 
721 	memset(&fake, 0, sizeof(fake));
722 	fake.pw_name = "NOUSER";
723 	fake.pw_passwd =
724 	    "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK";
725 	fake.pw_gecos = "NOUSER";
726 	fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid;
727 	fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid;
728 #ifdef HAVE_PW_CLASS_IN_PASSWD
729 	fake.pw_class = "";
730 #endif
731 	fake.pw_dir = "/nonexist";
732 	fake.pw_shell = "/nonexist";
733 
734 	return (&fake);
735 }
736