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Damien Miller7a8f5b32006-03-31 23:14:23 +11001/* $OpenBSD: auth.c,v 1.67 2006/03/30 11:40:21 dtucker Exp $ */
Damien Miller116e6df2002-05-22 15:06:28 +10002/*
Ben Lindstrom92a2e382001-03-05 06:59:27 +00003 * Copyright (c) 2000 Markus Friedl. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +11004 *
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.
Damien Millerb38eff82000-04-01 11:09:21 +100024 */
25
26#include "includes.h"
Damien Millerf17883e2006-03-15 11:45:54 +110027
28#include <sys/types.h>
29#include <sys/stat.h>
Damien Millerb38eff82000-04-01 11:09:21 +100030
Damien Miller03e20032006-03-15 11:16:59 +110031#ifdef HAVE_PATHS_H
Damien Millera9263d02006-03-15 11:18:26 +110032# include <paths.h>
Damien Miller03e20032006-03-15 11:16:59 +110033#endif
Damien Millerd2c208a2000-05-17 22:00:02 +100034#ifdef HAVE_LOGIN_H
35#include <login.h>
36#endif
Darren Tucker15ee7482004-02-22 09:43:15 +110037#ifdef USE_SHADOW
Damien Miller1f335fb2000-06-26 11:31:33 +100038#include <shadow.h>
Darren Tucker15ee7482004-02-22 09:43:15 +110039#endif
Damien Millerb38eff82000-04-01 11:09:21 +100040
Ben Lindstrom68c3ce12001-06-10 17:24:51 +000041#ifdef HAVE_LIBGEN_H
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +000042#include <libgen.h>
Ben Lindstrom68c3ce12001-06-10 17:24:51 +000043#endif
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +000044
Ben Lindstrom226cfa02001-01-22 05:34:40 +000045#include "xmalloc.h"
46#include "match.h"
47#include "groupaccess.h"
48#include "log.h"
49#include "servconf.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100050#include "auth.h"
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000051#include "auth-options.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000052#include "canohost.h"
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +000053#include "buffer.h"
54#include "bufaux.h"
Ben Lindstrom83647ce2001-06-25 04:30:16 +000055#include "uidswap.h"
Ben Lindstrom7ebb6352002-03-22 03:04:08 +000056#include "misc.h"
Ben Lindstroma574cda2002-05-15 16:16:14 +000057#include "bufaux.h"
58#include "packet.h"
Darren Tucker42d9dc72005-02-02 17:10:11 +110059#include "loginrec.h"
Darren Tucker269a1ea2005-02-03 00:20:53 +110060#include "monitor_wrap.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100061
Damien Millerb38eff82000-04-01 11:09:21 +100062/* import */
63extern ServerOptions options;
Damien Miller7a8f5b32006-03-31 23:14:23 +110064extern int use_privsep;
Darren Tuckerb9aa0a02003-07-08 22:59:59 +100065extern Buffer loginmsg;
Damien Millerb38eff82000-04-01 11:09:21 +100066
Ben Lindstroma574cda2002-05-15 16:16:14 +000067/* Debugging messages */
68Buffer auth_debug;
69int auth_debug_init;
70
Damien Millerb38eff82000-04-01 11:09:21 +100071/*
Kevin Steves7b61cfa2001-01-14 19:11:00 +000072 * Check if the user is allowed to log in via ssh. If user is listed
73 * in DenyUsers or one of user's groups is listed in DenyGroups, false
74 * will be returned. If AllowUsers isn't empty and user isn't listed
75 * there, or if AllowGroups isn't empty and one of user's groups isn't
76 * listed there, false will be returned.
Damien Millerb38eff82000-04-01 11:09:21 +100077 * If the user's shell is not executable, false will be returned.
Damien Miller4af51302000-04-16 11:18:38 +100078 * Otherwise true is returned.
Damien Millerb38eff82000-04-01 11:09:21 +100079 */
Damien Millereba71ba2000-04-29 23:57:08 +100080int
Damien Millerb38eff82000-04-01 11:09:21 +100081allowed_user(struct passwd * pw)
82{
83 struct stat st;
Darren Tucker43a0dc62003-08-26 14:22:12 +100084 const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
Damien Millere7cf07c2001-03-20 09:15:57 +110085 char *shell;
Damien Millereccb9de2005-06-17 12:59:34 +100086 u_int i;
Darren Tucker15ee7482004-02-22 09:43:15 +110087#ifdef USE_SHADOW
Darren Tuckere41bba52003-08-25 11:51:19 +100088 struct spwd *spw = NULL;
Tim Rice458c6bf2003-01-08 20:04:27 -080089#endif
Damien Millerb38eff82000-04-01 11:09:21 +100090
91 /* Shouldn't be called if pw is NULL, but better safe than sorry... */
Kevin Steves7b61cfa2001-01-14 19:11:00 +000092 if (!pw || !pw->pw_name)
Damien Millerb38eff82000-04-01 11:09:21 +100093 return 0;
94
Darren Tucker15ee7482004-02-22 09:43:15 +110095#ifdef USE_SHADOW
Darren Tuckere41bba52003-08-25 11:51:19 +100096 if (!options.use_pam)
97 spw = getspnam(pw->pw_name);
98#ifdef HAS_SHADOW_EXPIRE
Darren Tucker15ee7482004-02-22 09:43:15 +110099 if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw))
100 return 0;
Darren Tuckere41bba52003-08-25 11:51:19 +1000101#endif /* HAS_SHADOW_EXPIRE */
Darren Tucker15ee7482004-02-22 09:43:15 +1100102#endif /* USE_SHADOW */
Darren Tuckere41bba52003-08-25 11:51:19 +1000103
Damien Millera8e06ce2003-11-21 23:48:55 +1100104 /* grab passwd field for locked account check */
Darren Tucker15ee7482004-02-22 09:43:15 +1100105#ifdef USE_SHADOW
Darren Tuckere41bba52003-08-25 11:51:19 +1000106 if (spw != NULL)
Tim Rice66fd2172005-08-31 09:59:49 -0700107#if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
Tim Rice2291c002005-08-26 13:15:19 -0700108 passwd = get_iaf_password(pw);
109#else
Darren Tuckere41bba52003-08-25 11:51:19 +1000110 passwd = spw->sp_pwdp;
Tim Rice66fd2172005-08-31 09:59:49 -0700111#endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
Darren Tuckere41bba52003-08-25 11:51:19 +1000112#else
113 passwd = pw->pw_passwd;
Damien Miller06817f92003-01-07 23:55:59 +1100114#endif
115
Damien Millera8e06ce2003-11-21 23:48:55 +1100116 /* check for locked account */
Darren Tucker43a0dc62003-08-26 14:22:12 +1000117 if (!options.use_pam && passwd && *passwd) {
Darren Tuckere41bba52003-08-25 11:51:19 +1000118 int locked = 0;
119
120#ifdef LOCKED_PASSWD_STRING
121 if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0)
122 locked = 1;
123#endif
124#ifdef LOCKED_PASSWD_PREFIX
125 if (strncmp(passwd, LOCKED_PASSWD_PREFIX,
126 strlen(LOCKED_PASSWD_PREFIX)) == 0)
127 locked = 1;
128#endif
129#ifdef LOCKED_PASSWD_SUBSTR
130 if (strstr(passwd, LOCKED_PASSWD_SUBSTR))
131 locked = 1;
132#endif
Tim Rice66fd2172005-08-31 09:59:49 -0700133#if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
134 free(passwd);
135#endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */
Darren Tuckere41bba52003-08-25 11:51:19 +1000136 if (locked) {
137 logit("User %.100s not allowed because account is locked",
138 pw->pw_name);
139 return 0;
140 }
141 }
142
Damien Milleref7df542000-05-19 00:03:23 +1000143 /*
144 * Get the shell from the password data. An empty shell field is
145 * legal, and means /bin/sh.
146 */
147 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
148
149 /* deny if shell does not exists or is not executable */
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000150 if (stat(shell, &st) != 0) {
Damien Miller996acd22003-04-09 20:59:48 +1000151 logit("User %.100s not allowed because shell %.100s does not exist",
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000152 pw->pw_name, shell);
Damien Millerb38eff82000-04-01 11:09:21 +1000153 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000154 }
Ben Lindstromb61e6df2002-03-22 01:15:33 +0000155 if (S_ISREG(st.st_mode) == 0 ||
156 (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) {
Damien Miller996acd22003-04-09 20:59:48 +1000157 logit("User %.100s not allowed because shell %.100s is not executable",
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000158 pw->pw_name, shell);
Damien Millerb38eff82000-04-01 11:09:21 +1000159 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000160 }
Damien Millerb38eff82000-04-01 11:09:21 +1000161
Darren Tuckera8f553d2005-03-14 23:17:27 +1100162 if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
163 options.num_deny_groups > 0 || options.num_allow_groups > 0) {
Damien Miller3a961dc2003-06-03 10:25:48 +1000164 hostname = get_canonical_hostname(options.use_dns);
Ben Lindstrom3fb5d002002-03-05 01:42:42 +0000165 ipaddr = get_remote_ipaddr();
166 }
167
Damien Millerb38eff82000-04-01 11:09:21 +1000168 /* Return false if user is listed in DenyUsers */
169 if (options.num_deny_users > 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000170 for (i = 0; i < options.num_deny_users; i++)
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000171 if (match_user(pw->pw_name, hostname, ipaddr,
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000172 options.deny_users[i])) {
Darren Tucker094cd0b2005-01-24 21:56:48 +1100173 logit("User %.100s from %.100s not allowed "
174 "because listed in DenyUsers",
175 pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000176 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000177 }
Damien Millerb38eff82000-04-01 11:09:21 +1000178 }
179 /* Return false if AllowUsers isn't empty and user isn't listed there */
180 if (options.num_allow_users > 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000181 for (i = 0; i < options.num_allow_users; i++)
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000182 if (match_user(pw->pw_name, hostname, ipaddr,
Ben Lindstrom60260022001-07-04 04:56:44 +0000183 options.allow_users[i]))
Damien Millerb38eff82000-04-01 11:09:21 +1000184 break;
185 /* i < options.num_allow_users iff we break for loop */
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000186 if (i >= options.num_allow_users) {
Darren Tucker094cd0b2005-01-24 21:56:48 +1100187 logit("User %.100s from %.100s not allowed because "
188 "not listed in AllowUsers", pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000189 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000190 }
Damien Millerb38eff82000-04-01 11:09:21 +1000191 }
Damien Millerb38eff82000-04-01 11:09:21 +1000192 if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000193 /* Get the user's group access list (primary and supplementary) */
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000194 if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
Darren Tucker094cd0b2005-01-24 21:56:48 +1100195 logit("User %.100s from %.100s not allowed because "
196 "not in any group", pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000197 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000198 }
Damien Millerb38eff82000-04-01 11:09:21 +1000199
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000200 /* Return false if one of user's groups is listed in DenyGroups */
201 if (options.num_deny_groups > 0)
202 if (ga_match(options.deny_groups,
203 options.num_deny_groups)) {
204 ga_free();
Darren Tucker094cd0b2005-01-24 21:56:48 +1100205 logit("User %.100s from %.100s not allowed "
206 "because a group is listed in DenyGroups",
207 pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000208 return 0;
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000209 }
Damien Millerb38eff82000-04-01 11:09:21 +1000210 /*
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000211 * Return false if AllowGroups isn't empty and one of user's groups
Damien Millerb38eff82000-04-01 11:09:21 +1000212 * isn't listed there
213 */
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000214 if (options.num_allow_groups > 0)
215 if (!ga_match(options.allow_groups,
216 options.num_allow_groups)) {
217 ga_free();
Darren Tucker094cd0b2005-01-24 21:56:48 +1100218 logit("User %.100s from %.100s not allowed "
219 "because none of user's groups are listed "
220 "in AllowGroups", pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000221 return 0;
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000222 }
223 ga_free();
Damien Millerb38eff82000-04-01 11:09:21 +1000224 }
225
Darren Tucker0a9d43d2004-06-23 13:45:24 +1000226#ifdef CUSTOM_SYS_AUTH_ALLOWED_USER
Darren Tucker691d5232005-02-15 21:45:57 +1100227 if (!sys_auth_allowed_user(pw, &loginmsg))
Darren Tucker0a9d43d2004-06-23 13:45:24 +1000228 return 0;
229#endif
Damien Millerb38eff82000-04-01 11:09:21 +1000230
231 /* We found no reason not to let this user try to log on... */
232 return 1;
233}
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000234
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000235void
236auth_log(Authctxt *authctxt, int authenticated, char *method, char *info)
237{
238 void (*authlog) (const char *fmt,...) = verbose;
239 char *authmsg;
240
Damien Miller7a8f5b32006-03-31 23:14:23 +1100241 if (use_privsep && !mm_is_monitor() && !authctxt->postponed)
242 return;
243
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000244 /* Raise logging level */
245 if (authenticated == 1 ||
246 !authctxt->valid ||
Darren Tucker89413db2004-05-24 10:36:23 +1000247 authctxt->failures >= options.max_authtries / 2 ||
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000248 strcmp(method, "password") == 0)
Damien Miller2a3f20e2003-04-09 21:12:00 +1000249 authlog = logit;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000250
251 if (authctxt->postponed)
252 authmsg = "Postponed";
253 else
254 authmsg = authenticated ? "Accepted" : "Failed";
255
256 authlog("%s %s for %s%.100s from %.200s port %d%s",
257 authmsg,
258 method,
Darren Tucker5cb30ad2004-08-12 22:40:24 +1000259 authctxt->valid ? "" : "invalid user ",
Damien Millerf6552072001-11-12 11:06:06 +1100260 authctxt->user,
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000261 get_remote_ipaddr(),
262 get_remote_port(),
263 info);
Ben Lindstrome06eb682002-07-04 00:27:21 +0000264
Darren Tucker97363a82003-05-02 23:42:25 +1000265#ifdef CUSTOM_FAILED_LOGIN
Darren Tucker2fba9932005-02-02 23:30:24 +1100266 if (authenticated == 0 && !authctxt->postponed &&
267 (strcmp(method, "password") == 0 ||
Darren Tucker40d9a632005-02-04 15:19:44 +1100268 strncmp(method, "keyboard-interactive", 20) == 0 ||
269 strcmp(method, "challenge-response") == 0))
Darren Tucker42d9dc72005-02-02 17:10:11 +1100270 record_failed_login(authctxt->user,
271 get_canonical_hostname(options.use_dns), "ssh");
Darren Tucker97363a82003-05-02 23:42:25 +1000272#endif
Darren Tucker2e0cf0d2005-02-08 21:52:47 +1100273#ifdef SSH_AUDIT_EVENTS
Darren Tuckerf14b2aa2006-05-21 18:26:40 +1000274 if (authenticated == 0 && !authctxt->postponed)
275 audit_event(audit_classify_auth(method));
Darren Tucker269a1ea2005-02-03 00:20:53 +1100276#endif
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000277}
278
279/*
Ben Lindstromd8a90212001-02-15 03:08:27 +0000280 * Check whether root logins are disallowed.
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000281 */
282int
Ben Lindstromd8a90212001-02-15 03:08:27 +0000283auth_root_allowed(char *method)
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000284{
Ben Lindstromd8a90212001-02-15 03:08:27 +0000285 switch (options.permit_root_login) {
286 case PERMIT_YES:
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000287 return 1;
Ben Lindstromd8a90212001-02-15 03:08:27 +0000288 case PERMIT_NO_PASSWD:
289 if (strcmp(method, "password") != 0)
290 return 1;
291 break;
292 case PERMIT_FORCED_ONLY:
293 if (forced_command) {
Damien Miller996acd22003-04-09 20:59:48 +1000294 logit("Root login accepted for forced command.");
Ben Lindstromd8a90212001-02-15 03:08:27 +0000295 return 1;
296 }
297 break;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000298 }
Damien Miller996acd22003-04-09 20:59:48 +1000299 logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
Ben Lindstromd8a90212001-02-15 03:08:27 +0000300 return 0;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000301}
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000302
303
304/*
305 * Given a template and a passwd structure, build a filename
306 * by substituting % tokenised options. Currently, %% becomes '%',
307 * %h becomes the home directory and %u the username.
308 *
309 * This returns a buffer allocated by xmalloc.
310 */
Damien Miller6476cad2005-06-16 13:18:34 +1000311static char *
312expand_authorized_keys(const char *filename, struct passwd *pw)
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000313{
Damien Miller07d86be2006-03-26 14:19:21 +1100314 char *file, ret[MAXPATHLEN];
315 int i;
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000316
Damien Miller6476cad2005-06-16 13:18:34 +1000317 file = percent_expand(filename, "h", pw->pw_dir,
318 "u", pw->pw_name, (char *)NULL);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000319
320 /*
321 * Ensure that filename starts anchored. If not, be backward
322 * compatible and prepend the '%h/'
323 */
Damien Miller6476cad2005-06-16 13:18:34 +1000324 if (*file == '/')
325 return (file);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000326
Damien Miller07d86be2006-03-26 14:19:21 +1100327 i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file);
328 if (i < 0 || (size_t)i >= sizeof(ret))
Damien Miller6476cad2005-06-16 13:18:34 +1000329 fatal("expand_authorized_keys: path too long");
Damien Miller6476cad2005-06-16 13:18:34 +1000330 xfree(file);
Damien Miller07d86be2006-03-26 14:19:21 +1100331 return (xstrdup(ret));
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000332}
333
334char *
335authorized_keys_file(struct passwd *pw)
336{
Damien Miller6476cad2005-06-16 13:18:34 +1000337 return expand_authorized_keys(options.authorized_keys_file, pw);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000338}
339
340char *
341authorized_keys_file2(struct passwd *pw)
342{
Damien Miller6476cad2005-06-16 13:18:34 +1000343 return expand_authorized_keys(options.authorized_keys_file2, pw);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000344}
345
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000346/* return ok if key exists in sysfile or userfile */
347HostStatus
348check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
349 const char *sysfile, const char *userfile)
350{
351 Key *found;
352 char *user_hostfile;
353 struct stat st;
Ben Lindstrom65366a82001-12-06 16:32:47 +0000354 HostStatus host_status;
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000355
356 /* Check if we know the host and its host key. */
357 found = key_new(key->type);
358 host_status = check_host_in_hostfile(sysfile, host, key, found, NULL);
359
360 if (host_status != HOST_OK && userfile != NULL) {
361 user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
362 if (options.strict_modes &&
363 (stat(user_hostfile, &st) == 0) &&
364 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
Damien Miller9f0f5c62001-12-21 14:45:46 +1100365 (st.st_mode & 022) != 0)) {
Damien Miller996acd22003-04-09 20:59:48 +1000366 logit("Authentication refused for %.100s: "
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000367 "bad owner or modes for %.200s",
368 pw->pw_name, user_hostfile);
369 } else {
370 temporarily_use_uid(pw);
371 host_status = check_host_in_hostfile(user_hostfile,
372 host, key, found, NULL);
373 restore_uid();
374 }
375 xfree(user_hostfile);
376 }
377 key_free(found);
378
379 debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ?
380 "ok" : "not found", host);
381 return host_status;
382}
383
384
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000385/*
386 * Check a given file for security. This is defined as all components
Ben Lindstromd4ee3492002-08-20 18:42:13 +0000387 * of the path to the file must be owned by either the owner of
Ben Lindstrom60567ff2001-06-05 20:27:53 +0000388 * of the file or root and no directories must be group or world writable.
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000389 *
390 * XXX Should any specific check be done for sym links ?
391 *
392 * Takes an open file descriptor, the file name, a uid and and
393 * error buffer plus max size as arguments.
394 *
395 * Returns 0 on success and -1 on failure
396 */
397int
Ben Lindstrom248c0782001-07-04 03:40:39 +0000398secure_filename(FILE *f, const char *file, struct passwd *pw,
399 char *err, size_t errlen)
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000400{
Ben Lindstrom248c0782001-07-04 03:40:39 +0000401 uid_t uid = pw->pw_uid;
Ben Lindstromc3e49e72001-10-03 17:55:26 +0000402 char buf[MAXPATHLEN], homedir[MAXPATHLEN];
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000403 char *cp;
Ben Lindstrom485075e2002-11-09 15:45:12 +0000404 int comparehome = 0;
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000405 struct stat st;
406
407 if (realpath(file, buf) == NULL) {
408 snprintf(err, errlen, "realpath %s failed: %s", file,
409 strerror(errno));
410 return -1;
411 }
Ben Lindstrom485075e2002-11-09 15:45:12 +0000412 if (realpath(pw->pw_dir, homedir) != NULL)
413 comparehome = 1;
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000414
415 /* check the open file to avoid races */
416 if (fstat(fileno(f), &st) < 0 ||
417 (st.st_uid != 0 && st.st_uid != uid) ||
418 (st.st_mode & 022) != 0) {
419 snprintf(err, errlen, "bad ownership or modes for file %s",
420 buf);
421 return -1;
422 }
423
424 /* for each component of the canonical path, walking upwards */
425 for (;;) {
426 if ((cp = dirname(buf)) == NULL) {
427 snprintf(err, errlen, "dirname() failed");
428 return -1;
429 }
430 strlcpy(buf, cp, sizeof(buf));
431
432 debug3("secure_filename: checking '%s'", buf);
433 if (stat(buf, &st) < 0 ||
434 (st.st_uid != 0 && st.st_uid != uid) ||
435 (st.st_mode & 022) != 0) {
Damien Miller9f0f5c62001-12-21 14:45:46 +1100436 snprintf(err, errlen,
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000437 "bad ownership or modes for directory %s", buf);
438 return -1;
439 }
440
Damien Miller0ae6e002001-07-14 12:21:34 +1000441 /* If are passed the homedir then we can stop */
Ben Lindstrom485075e2002-11-09 15:45:12 +0000442 if (comparehome && strcmp(homedir, buf) == 0) {
Damien Miller0ae6e002001-07-14 12:21:34 +1000443 debug3("secure_filename: terminating check at '%s'",
444 buf);
445 break;
446 }
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000447 /*
448 * dirname should always complete with a "/" path,
449 * but we can be paranoid and check for "." too
450 */
451 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
452 break;
453 }
454 return 0;
455}
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000456
457struct passwd *
458getpwnamallow(const char *user)
459{
Ben Lindstromb481e132002-03-22 01:35:47 +0000460#ifdef HAVE_LOGIN_CAP
461 extern login_cap_t *lc;
462#ifdef BSD_AUTH
463 auth_session_t *as;
464#endif
465#endif
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000466 struct passwd *pw;
467
468 pw = getpwnam(user);
Damien Miller6f0a1882002-09-22 01:26:51 +1000469 if (pw == NULL) {
Damien Millera22f2d72004-07-21 20:48:24 +1000470 logit("Invalid user %.100s from %.100s",
Damien Miller6f0a1882002-09-22 01:26:51 +1000471 user, get_remote_ipaddr());
Darren Tucker97363a82003-05-02 23:42:25 +1000472#ifdef CUSTOM_FAILED_LOGIN
Darren Tucker42d9dc72005-02-02 17:10:11 +1100473 record_failed_login(user,
474 get_canonical_hostname(options.use_dns), "ssh");
Ben Lindstromf5397c02002-11-09 16:11:10 +0000475#endif
Darren Tucker2e0cf0d2005-02-08 21:52:47 +1100476#ifdef SSH_AUDIT_EVENTS
477 audit_event(SSH_INVALID_USER);
478#endif /* SSH_AUDIT_EVENTS */
Damien Miller6f0a1882002-09-22 01:26:51 +1000479 return (NULL);
480 }
481 if (!allowed_user(pw))
Ben Lindstromb481e132002-03-22 01:35:47 +0000482 return (NULL);
483#ifdef HAVE_LOGIN_CAP
484 if ((lc = login_getclass(pw->pw_class)) == NULL) {
485 debug("unable to get login class: %s", user);
486 return (NULL);
487 }
488#ifdef BSD_AUTH
489 if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 ||
Damien Miller13e35a02002-05-22 14:04:11 +1000490 auth_approval(as, lc, pw->pw_name, "ssh") <= 0) {
Ben Lindstromb481e132002-03-22 01:35:47 +0000491 debug("Approval failure for %s", user);
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000492 pw = NULL;
Ben Lindstromb481e132002-03-22 01:35:47 +0000493 }
494 if (as != NULL)
495 auth_close(as);
496#endif
497#endif
Ben Lindstromf34e4eb2002-03-22 03:08:30 +0000498 if (pw != NULL)
499 return (pwcopy(pw));
500 return (NULL);
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000501}
Ben Lindstroma574cda2002-05-15 16:16:14 +0000502
503void
504auth_debug_add(const char *fmt,...)
505{
506 char buf[1024];
507 va_list args;
508
509 if (!auth_debug_init)
510 return;
511
512 va_start(args, fmt);
513 vsnprintf(buf, sizeof(buf), fmt, args);
514 va_end(args);
515 buffer_put_cstring(&auth_debug, buf);
516}
517
518void
519auth_debug_send(void)
520{
521 char *msg;
522
523 if (!auth_debug_init)
524 return;
525 while (buffer_len(&auth_debug)) {
526 msg = buffer_get_string(&auth_debug, NULL);
527 packet_send_debug("%s", msg);
528 xfree(msg);
529 }
530}
531
532void
533auth_debug_reset(void)
534{
535 if (auth_debug_init)
536 buffer_clear(&auth_debug);
537 else {
538 buffer_init(&auth_debug);
539 auth_debug_init = 1;
540 }
541}
Damien Miller856f0be2003-09-03 07:32:45 +1000542
543struct passwd *
544fakepw(void)
545{
546 static struct passwd fake;
547
548 memset(&fake, 0, sizeof(fake));
549 fake.pw_name = "NOUSER";
550 fake.pw_passwd =
Damien Miller787b2ec2003-11-21 23:56:47 +1100551 "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK";
Damien Miller856f0be2003-09-03 07:32:45 +1000552 fake.pw_gecos = "NOUSER";
Darren Tucker1f8311c2004-05-13 16:39:33 +1000553 fake.pw_uid = (uid_t)-1;
554 fake.pw_gid = (gid_t)-1;
Damien Miller856f0be2003-09-03 07:32:45 +1000555#ifdef HAVE_PW_CLASS_IN_PASSWD
556 fake.pw_class = "";
557#endif
558 fake.pw_dir = "/nonexist";
559 fake.pw_shell = "/nonexist";
560
561 return (&fake);
562}