auth.c revision 295367 
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: stable/10/crypto/openssh/auth.c 295367 2016-02-07 11:38:54Z des $");
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 */
80extern ServerOptions options;
81extern int use_privsep;
82extern Buffer loginmsg;
83extern struct passwd *privsep_pw;
84
85/* Debugging messages */
86Buffer auth_debug;
87int 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 */
98int
99allowed_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
257void
258auth_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
274void
275auth_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
332void
333auth_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 */
349int
350auth_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 */
380char *
381expand_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
403char *
404authorized_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 */
412HostStatus
413check_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 */
470int
471auth_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 */
534static int
535secure_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
549static FILE *
550auth_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
592FILE *
593auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes)
594{
595	return auth_openfile(file, pw, strict_modes, 1, "authorized keys");
596}
597
598FILE *
599auth_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
605struct passwd *
606getpwnamallow(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 */
677int
678auth_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
715void
716auth_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
730void
731auth_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
744void
745auth_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
755struct passwd *
756fakepw(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