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Damien Miller733124b2007-10-26 14:25:12 +10001/* $OpenBSD: auth.c,v 1.78 2007/09/21 08:15:29 djm 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 Miller8dbffe72006-08-05 11:02:17 +100030#include <sys/param.h>
Damien Millerb38eff82000-04-01 11:09:21 +100031
Damien Miller36cbe412006-08-05 12:54:24 +100032#include <netinet/in.h>
33
Darren Tucker39972492006-07-12 22:22:46 +100034#include <errno.h>
Damien Miller03e20032006-03-15 11:16:59 +110035#ifdef HAVE_PATHS_H
Damien Millera9263d02006-03-15 11:18:26 +110036# include <paths.h>
Damien Miller03e20032006-03-15 11:16:59 +110037#endif
Damien Miller9f2abc42006-07-10 20:53:08 +100038#include <pwd.h>
Damien Millerd2c208a2000-05-17 22:00:02 +100039#ifdef HAVE_LOGIN_H
40#include <login.h>
41#endif
Darren Tucker15ee7482004-02-22 09:43:15 +110042#ifdef USE_SHADOW
Damien Miller1f335fb2000-06-26 11:31:33 +100043#include <shadow.h>
Darren Tucker15ee7482004-02-22 09:43:15 +110044#endif
Ben Lindstrom68c3ce12001-06-10 17:24:51 +000045#ifdef HAVE_LIBGEN_H
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +000046#include <libgen.h>
Ben Lindstrom68c3ce12001-06-10 17:24:51 +000047#endif
Darren Tucker5d196262006-07-12 22:15:16 +100048#include <stdarg.h>
Damien Millera7a73ee2006-08-05 11:37:59 +100049#include <stdio.h>
Damien Millere3476ed2006-07-24 14:13:33 +100050#include <string.h>
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +000051
Ben Lindstrom226cfa02001-01-22 05:34:40 +000052#include "xmalloc.h"
53#include "match.h"
54#include "groupaccess.h"
55#include "log.h"
Damien Millerd7834352006-08-05 12:39:39 +100056#include "buffer.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000057#include "servconf.h"
Damien Millerd7834352006-08-05 12:39:39 +100058#include "key.h"
59#include "hostfile.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100060#include "auth.h"
Ben Lindstromdb65e8f2001-01-19 04:26:52 +000061#include "auth-options.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000062#include "canohost.h"
Ben Lindstrom83647ce2001-06-25 04:30:16 +000063#include "uidswap.h"
Ben Lindstrom7ebb6352002-03-22 03:04:08 +000064#include "misc.h"
Ben Lindstroma574cda2002-05-15 16:16:14 +000065#include "packet.h"
Darren Tucker42d9dc72005-02-02 17:10:11 +110066#include "loginrec.h"
Damien Millerd7834352006-08-05 12:39:39 +100067#ifdef GSSAPI
68#include "ssh-gss.h"
69#endif
Darren Tucker269a1ea2005-02-03 00:20:53 +110070#include "monitor_wrap.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100071
Damien Millerb38eff82000-04-01 11:09:21 +100072/* import */
73extern ServerOptions options;
Damien Miller7a8f5b32006-03-31 23:14:23 +110074extern int use_privsep;
Darren Tuckerb9aa0a02003-07-08 22:59:59 +100075extern Buffer loginmsg;
Damien Miller6433df02006-09-07 10:36:43 +100076extern struct passwd *privsep_pw;
Damien Millerb38eff82000-04-01 11:09:21 +100077
Ben Lindstroma574cda2002-05-15 16:16:14 +000078/* Debugging messages */
79Buffer auth_debug;
80int auth_debug_init;
81
Damien Millerb38eff82000-04-01 11:09:21 +100082/*
Kevin Steves7b61cfa2001-01-14 19:11:00 +000083 * Check if the user is allowed to log in via ssh. If user is listed
84 * in DenyUsers or one of user's groups is listed in DenyGroups, false
85 * will be returned. If AllowUsers isn't empty and user isn't listed
86 * there, or if AllowGroups isn't empty and one of user's groups isn't
87 * listed there, false will be returned.
Damien Millerb38eff82000-04-01 11:09:21 +100088 * If the user's shell is not executable, false will be returned.
Damien Miller4af51302000-04-16 11:18:38 +100089 * Otherwise true is returned.
Damien Millerb38eff82000-04-01 11:09:21 +100090 */
Damien Millereba71ba2000-04-29 23:57:08 +100091int
Damien Millerb38eff82000-04-01 11:09:21 +100092allowed_user(struct passwd * pw)
93{
94 struct stat st;
Darren Tucker43a0dc62003-08-26 14:22:12 +100095 const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL;
Damien Millere7cf07c2001-03-20 09:15:57 +110096 char *shell;
Damien Millereccb9de2005-06-17 12:59:34 +100097 u_int i;
Darren Tucker15ee7482004-02-22 09:43:15 +110098#ifdef USE_SHADOW
Darren Tuckere41bba52003-08-25 11:51:19 +100099 struct spwd *spw = NULL;
Tim Rice458c6bf2003-01-08 20:04:27 -0800100#endif
Damien Millerb38eff82000-04-01 11:09:21 +1000101
102 /* Shouldn't be called if pw is NULL, but better safe than sorry... */
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000103 if (!pw || !pw->pw_name)
Damien Millerb38eff82000-04-01 11:09:21 +1000104 return 0;
105
Darren Tucker15ee7482004-02-22 09:43:15 +1100106#ifdef USE_SHADOW
Darren Tuckere41bba52003-08-25 11:51:19 +1000107 if (!options.use_pam)
108 spw = getspnam(pw->pw_name);
109#ifdef HAS_SHADOW_EXPIRE
Darren Tucker15ee7482004-02-22 09:43:15 +1100110 if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw))
111 return 0;
Darren Tuckere41bba52003-08-25 11:51:19 +1000112#endif /* HAS_SHADOW_EXPIRE */
Darren Tucker15ee7482004-02-22 09:43:15 +1100113#endif /* USE_SHADOW */
Darren Tuckere41bba52003-08-25 11:51:19 +1000114
Damien Millera8e06ce2003-11-21 23:48:55 +1100115 /* grab passwd field for locked account check */
Darren Tucker15ee7482004-02-22 09:43:15 +1100116#ifdef USE_SHADOW
Darren Tuckere41bba52003-08-25 11:51:19 +1000117 if (spw != NULL)
Tim Rice99203ec2007-03-26 09:35:28 -0700118#ifdef USE_LIBIAF
Tim Rice2291c002005-08-26 13:15:19 -0700119 passwd = get_iaf_password(pw);
120#else
Darren Tuckere41bba52003-08-25 11:51:19 +1000121 passwd = spw->sp_pwdp;
Tim Rice99203ec2007-03-26 09:35:28 -0700122#endif /* USE_LIBIAF */
Darren Tuckere41bba52003-08-25 11:51:19 +1000123#else
124 passwd = pw->pw_passwd;
Damien Miller06817f92003-01-07 23:55:59 +1100125#endif
126
Damien Millera8e06ce2003-11-21 23:48:55 +1100127 /* check for locked account */
Darren Tucker43a0dc62003-08-26 14:22:12 +1000128 if (!options.use_pam && passwd && *passwd) {
Darren Tuckere41bba52003-08-25 11:51:19 +1000129 int locked = 0;
130
131#ifdef LOCKED_PASSWD_STRING
132 if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0)
133 locked = 1;
134#endif
135#ifdef LOCKED_PASSWD_PREFIX
136 if (strncmp(passwd, LOCKED_PASSWD_PREFIX,
137 strlen(LOCKED_PASSWD_PREFIX)) == 0)
138 locked = 1;
139#endif
140#ifdef LOCKED_PASSWD_SUBSTR
141 if (strstr(passwd, LOCKED_PASSWD_SUBSTR))
142 locked = 1;
143#endif
Tim Rice99203ec2007-03-26 09:35:28 -0700144#ifdef USE_LIBIAF
Tim Rice66fd2172005-08-31 09:59:49 -0700145 free(passwd);
Tim Rice99203ec2007-03-26 09:35:28 -0700146#endif /* USE_LIBIAF */
Darren Tuckere41bba52003-08-25 11:51:19 +1000147 if (locked) {
148 logit("User %.100s not allowed because account is locked",
149 pw->pw_name);
150 return 0;
151 }
152 }
153
Damien Milleref7df542000-05-19 00:03:23 +1000154 /*
155 * Get the shell from the password data. An empty shell field is
156 * legal, and means /bin/sh.
157 */
158 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
159
160 /* deny if shell does not exists or is not executable */
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000161 if (stat(shell, &st) != 0) {
Damien Miller996acd22003-04-09 20:59:48 +1000162 logit("User %.100s not allowed because shell %.100s does not exist",
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000163 pw->pw_name, shell);
Damien Millerb38eff82000-04-01 11:09:21 +1000164 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000165 }
Ben Lindstromb61e6df2002-03-22 01:15:33 +0000166 if (S_ISREG(st.st_mode) == 0 ||
167 (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) {
Damien Miller996acd22003-04-09 20:59:48 +1000168 logit("User %.100s not allowed because shell %.100s is not executable",
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000169 pw->pw_name, shell);
Damien Millerb38eff82000-04-01 11:09:21 +1000170 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000171 }
Damien Millerb38eff82000-04-01 11:09:21 +1000172
Darren Tuckera8f553d2005-03-14 23:17:27 +1100173 if (options.num_deny_users > 0 || options.num_allow_users > 0 ||
174 options.num_deny_groups > 0 || options.num_allow_groups > 0) {
Damien Miller3a961dc2003-06-03 10:25:48 +1000175 hostname = get_canonical_hostname(options.use_dns);
Ben Lindstrom3fb5d002002-03-05 01:42:42 +0000176 ipaddr = get_remote_ipaddr();
177 }
178
Damien Millerb38eff82000-04-01 11:09:21 +1000179 /* Return false if user is listed in DenyUsers */
180 if (options.num_deny_users > 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000181 for (i = 0; i < options.num_deny_users; i++)
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000182 if (match_user(pw->pw_name, hostname, ipaddr,
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000183 options.deny_users[i])) {
Darren Tucker094cd0b2005-01-24 21:56:48 +1100184 logit("User %.100s from %.100s not allowed "
185 "because listed in DenyUsers",
186 pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000187 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000188 }
Damien Millerb38eff82000-04-01 11:09:21 +1000189 }
190 /* Return false if AllowUsers isn't empty and user isn't listed there */
191 if (options.num_allow_users > 0) {
Damien Millerb38eff82000-04-01 11:09:21 +1000192 for (i = 0; i < options.num_allow_users; i++)
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000193 if (match_user(pw->pw_name, hostname, ipaddr,
Ben Lindstrom60260022001-07-04 04:56:44 +0000194 options.allow_users[i]))
Damien Millerb38eff82000-04-01 11:09:21 +1000195 break;
196 /* i < options.num_allow_users iff we break for loop */
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000197 if (i >= options.num_allow_users) {
Darren Tucker094cd0b2005-01-24 21:56:48 +1100198 logit("User %.100s from %.100s not allowed because "
199 "not listed in AllowUsers", pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000200 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000201 }
Damien Millerb38eff82000-04-01 11:09:21 +1000202 }
Damien Millerb38eff82000-04-01 11:09:21 +1000203 if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000204 /* Get the user's group access list (primary and supplementary) */
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000205 if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
Darren Tucker094cd0b2005-01-24 21:56:48 +1100206 logit("User %.100s from %.100s not allowed because "
207 "not in any group", pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000208 return 0;
Ben Lindstrom6ef9ec62002-03-05 01:40:37 +0000209 }
Damien Millerb38eff82000-04-01 11:09:21 +1000210
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000211 /* Return false if one of user's groups is listed in DenyGroups */
212 if (options.num_deny_groups > 0)
213 if (ga_match(options.deny_groups,
214 options.num_deny_groups)) {
215 ga_free();
Darren Tucker094cd0b2005-01-24 21:56:48 +1100216 logit("User %.100s from %.100s not allowed "
217 "because a group is listed in DenyGroups",
218 pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000219 return 0;
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000220 }
Damien Millerb38eff82000-04-01 11:09:21 +1000221 /*
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000222 * Return false if AllowGroups isn't empty and one of user's groups
Damien Millerb38eff82000-04-01 11:09:21 +1000223 * isn't listed there
224 */
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000225 if (options.num_allow_groups > 0)
226 if (!ga_match(options.allow_groups,
227 options.num_allow_groups)) {
228 ga_free();
Darren Tucker094cd0b2005-01-24 21:56:48 +1100229 logit("User %.100s from %.100s not allowed "
230 "because none of user's groups are listed "
231 "in AllowGroups", pw->pw_name, hostname);
Damien Millerb38eff82000-04-01 11:09:21 +1000232 return 0;
Kevin Steves7b61cfa2001-01-14 19:11:00 +0000233 }
234 ga_free();
Damien Millerb38eff82000-04-01 11:09:21 +1000235 }
236
Darren Tucker0a9d43d2004-06-23 13:45:24 +1000237#ifdef CUSTOM_SYS_AUTH_ALLOWED_USER
Darren Tucker691d5232005-02-15 21:45:57 +1100238 if (!sys_auth_allowed_user(pw, &loginmsg))
Darren Tucker0a9d43d2004-06-23 13:45:24 +1000239 return 0;
240#endif
Damien Millerb38eff82000-04-01 11:09:21 +1000241
242 /* We found no reason not to let this user try to log on... */
243 return 1;
244}
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000245
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000246void
247auth_log(Authctxt *authctxt, int authenticated, char *method, char *info)
248{
249 void (*authlog) (const char *fmt,...) = verbose;
250 char *authmsg;
251
Damien Miller7a8f5b32006-03-31 23:14:23 +1100252 if (use_privsep && !mm_is_monitor() && !authctxt->postponed)
253 return;
254
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000255 /* Raise logging level */
256 if (authenticated == 1 ||
257 !authctxt->valid ||
Darren Tucker89413db2004-05-24 10:36:23 +1000258 authctxt->failures >= options.max_authtries / 2 ||
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000259 strcmp(method, "password") == 0)
Damien Miller2a3f20e2003-04-09 21:12:00 +1000260 authlog = logit;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000261
262 if (authctxt->postponed)
263 authmsg = "Postponed";
264 else
265 authmsg = authenticated ? "Accepted" : "Failed";
266
267 authlog("%s %s for %s%.100s from %.200s port %d%s",
268 authmsg,
269 method,
Darren Tucker5cb30ad2004-08-12 22:40:24 +1000270 authctxt->valid ? "" : "invalid user ",
Damien Millerf6552072001-11-12 11:06:06 +1100271 authctxt->user,
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000272 get_remote_ipaddr(),
273 get_remote_port(),
274 info);
Ben Lindstrome06eb682002-07-04 00:27:21 +0000275
Darren Tucker97363a82003-05-02 23:42:25 +1000276#ifdef CUSTOM_FAILED_LOGIN
Darren Tucker2fba9932005-02-02 23:30:24 +1100277 if (authenticated == 0 && !authctxt->postponed &&
278 (strcmp(method, "password") == 0 ||
Darren Tucker40d9a632005-02-04 15:19:44 +1100279 strncmp(method, "keyboard-interactive", 20) == 0 ||
280 strcmp(method, "challenge-response") == 0))
Darren Tucker42d9dc72005-02-02 17:10:11 +1100281 record_failed_login(authctxt->user,
282 get_canonical_hostname(options.use_dns), "ssh");
Darren Tucker26d4e192006-08-30 22:33:09 +1000283# ifdef WITH_AIXAUTHENTICATE
284 if (authenticated)
285 sys_auth_record_login(authctxt->user,
286 get_canonical_hostname(options.use_dns), "ssh", &loginmsg);
287# endif
Darren Tucker97363a82003-05-02 23:42:25 +1000288#endif
Darren Tucker2e0cf0d2005-02-08 21:52:47 +1100289#ifdef SSH_AUDIT_EVENTS
Darren Tuckerf14b2aa2006-05-21 18:26:40 +1000290 if (authenticated == 0 && !authctxt->postponed)
291 audit_event(audit_classify_auth(method));
Darren Tucker269a1ea2005-02-03 00:20:53 +1100292#endif
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000293}
294
295/*
Ben Lindstromd8a90212001-02-15 03:08:27 +0000296 * Check whether root logins are disallowed.
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000297 */
298int
Ben Lindstromd8a90212001-02-15 03:08:27 +0000299auth_root_allowed(char *method)
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000300{
Ben Lindstromd8a90212001-02-15 03:08:27 +0000301 switch (options.permit_root_login) {
302 case PERMIT_YES:
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000303 return 1;
Ben Lindstromd8a90212001-02-15 03:08:27 +0000304 case PERMIT_NO_PASSWD:
305 if (strcmp(method, "password") != 0)
306 return 1;
307 break;
308 case PERMIT_FORCED_ONLY:
309 if (forced_command) {
Damien Miller996acd22003-04-09 20:59:48 +1000310 logit("Root login accepted for forced command.");
Ben Lindstromd8a90212001-02-15 03:08:27 +0000311 return 1;
312 }
313 break;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000314 }
Damien Miller996acd22003-04-09 20:59:48 +1000315 logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr());
Ben Lindstromd8a90212001-02-15 03:08:27 +0000316 return 0;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000317}
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000318
319
320/*
321 * Given a template and a passwd structure, build a filename
322 * by substituting % tokenised options. Currently, %% becomes '%',
323 * %h becomes the home directory and %u the username.
324 *
325 * This returns a buffer allocated by xmalloc.
326 */
Damien Miller6476cad2005-06-16 13:18:34 +1000327static char *
328expand_authorized_keys(const char *filename, struct passwd *pw)
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000329{
Damien Miller07d86be2006-03-26 14:19:21 +1100330 char *file, ret[MAXPATHLEN];
331 int i;
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000332
Damien Miller6476cad2005-06-16 13:18:34 +1000333 file = percent_expand(filename, "h", pw->pw_dir,
334 "u", pw->pw_name, (char *)NULL);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000335
336 /*
337 * Ensure that filename starts anchored. If not, be backward
338 * compatible and prepend the '%h/'
339 */
Damien Miller6476cad2005-06-16 13:18:34 +1000340 if (*file == '/')
341 return (file);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000342
Damien Miller07d86be2006-03-26 14:19:21 +1100343 i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file);
344 if (i < 0 || (size_t)i >= sizeof(ret))
Damien Miller6476cad2005-06-16 13:18:34 +1000345 fatal("expand_authorized_keys: path too long");
Damien Miller6476cad2005-06-16 13:18:34 +1000346 xfree(file);
Damien Miller07d86be2006-03-26 14:19:21 +1100347 return (xstrdup(ret));
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000348}
349
350char *
351authorized_keys_file(struct passwd *pw)
352{
Damien Miller6476cad2005-06-16 13:18:34 +1000353 return expand_authorized_keys(options.authorized_keys_file, pw);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000354}
355
356char *
357authorized_keys_file2(struct passwd *pw)
358{
Damien Miller6476cad2005-06-16 13:18:34 +1000359 return expand_authorized_keys(options.authorized_keys_file2, pw);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000360}
361
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000362/* return ok if key exists in sysfile or userfile */
363HostStatus
364check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
365 const char *sysfile, const char *userfile)
366{
367 Key *found;
368 char *user_hostfile;
369 struct stat st;
Ben Lindstrom65366a82001-12-06 16:32:47 +0000370 HostStatus host_status;
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000371
372 /* Check if we know the host and its host key. */
373 found = key_new(key->type);
374 host_status = check_host_in_hostfile(sysfile, host, key, found, NULL);
375
376 if (host_status != HOST_OK && userfile != NULL) {
377 user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
378 if (options.strict_modes &&
379 (stat(user_hostfile, &st) == 0) &&
380 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
Damien Miller9f0f5c62001-12-21 14:45:46 +1100381 (st.st_mode & 022) != 0)) {
Damien Miller996acd22003-04-09 20:59:48 +1000382 logit("Authentication refused for %.100s: "
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000383 "bad owner or modes for %.200s",
384 pw->pw_name, user_hostfile);
385 } else {
386 temporarily_use_uid(pw);
387 host_status = check_host_in_hostfile(user_hostfile,
388 host, key, found, NULL);
389 restore_uid();
390 }
391 xfree(user_hostfile);
392 }
393 key_free(found);
394
395 debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ?
396 "ok" : "not found", host);
397 return host_status;
398}
399
400
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000401/*
402 * Check a given file for security. This is defined as all components
Ben Lindstromd4ee3492002-08-20 18:42:13 +0000403 * of the path to the file must be owned by either the owner of
Ben Lindstrom60567ff2001-06-05 20:27:53 +0000404 * of the file or root and no directories must be group or world writable.
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000405 *
406 * XXX Should any specific check be done for sym links ?
407 *
408 * Takes an open file descriptor, the file name, a uid and and
409 * error buffer plus max size as arguments.
410 *
411 * Returns 0 on success and -1 on failure
412 */
413int
Ben Lindstrom248c0782001-07-04 03:40:39 +0000414secure_filename(FILE *f, const char *file, struct passwd *pw,
415 char *err, size_t errlen)
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000416{
Ben Lindstrom248c0782001-07-04 03:40:39 +0000417 uid_t uid = pw->pw_uid;
Ben Lindstromc3e49e72001-10-03 17:55:26 +0000418 char buf[MAXPATHLEN], homedir[MAXPATHLEN];
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000419 char *cp;
Ben Lindstrom485075e2002-11-09 15:45:12 +0000420 int comparehome = 0;
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000421 struct stat st;
422
423 if (realpath(file, buf) == NULL) {
424 snprintf(err, errlen, "realpath %s failed: %s", file,
425 strerror(errno));
426 return -1;
427 }
Ben Lindstrom485075e2002-11-09 15:45:12 +0000428 if (realpath(pw->pw_dir, homedir) != NULL)
429 comparehome = 1;
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000430
431 /* check the open file to avoid races */
432 if (fstat(fileno(f), &st) < 0 ||
433 (st.st_uid != 0 && st.st_uid != uid) ||
434 (st.st_mode & 022) != 0) {
435 snprintf(err, errlen, "bad ownership or modes for file %s",
436 buf);
437 return -1;
438 }
439
440 /* for each component of the canonical path, walking upwards */
441 for (;;) {
442 if ((cp = dirname(buf)) == NULL) {
443 snprintf(err, errlen, "dirname() failed");
444 return -1;
445 }
446 strlcpy(buf, cp, sizeof(buf));
447
448 debug3("secure_filename: checking '%s'", buf);
449 if (stat(buf, &st) < 0 ||
450 (st.st_uid != 0 && st.st_uid != uid) ||
451 (st.st_mode & 022) != 0) {
Damien Miller9f0f5c62001-12-21 14:45:46 +1100452 snprintf(err, errlen,
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000453 "bad ownership or modes for directory %s", buf);
454 return -1;
455 }
456
Damien Miller0ae6e002001-07-14 12:21:34 +1000457 /* If are passed the homedir then we can stop */
Ben Lindstrom485075e2002-11-09 15:45:12 +0000458 if (comparehome && strcmp(homedir, buf) == 0) {
Damien Miller0ae6e002001-07-14 12:21:34 +1000459 debug3("secure_filename: terminating check at '%s'",
460 buf);
461 break;
462 }
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000463 /*
464 * dirname should always complete with a "/" path,
465 * but we can be paranoid and check for "." too
466 */
467 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
468 break;
469 }
470 return 0;
471}
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000472
473struct passwd *
474getpwnamallow(const char *user)
475{
Ben Lindstromb481e132002-03-22 01:35:47 +0000476#ifdef HAVE_LOGIN_CAP
477 extern login_cap_t *lc;
478#ifdef BSD_AUTH
479 auth_session_t *as;
480#endif
481#endif
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000482 struct passwd *pw;
483
Darren Tucker45150472006-07-12 22:34:17 +1000484 parse_server_match_config(&options, user,
485 get_canonical_hostname(options.use_dns), get_remote_ipaddr());
486
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000487 pw = getpwnam(user);
Damien Miller6f0a1882002-09-22 01:26:51 +1000488 if (pw == NULL) {
Damien Millera22f2d72004-07-21 20:48:24 +1000489 logit("Invalid user %.100s from %.100s",
Damien Miller6f0a1882002-09-22 01:26:51 +1000490 user, get_remote_ipaddr());
Darren Tucker97363a82003-05-02 23:42:25 +1000491#ifdef CUSTOM_FAILED_LOGIN
Darren Tucker42d9dc72005-02-02 17:10:11 +1100492 record_failed_login(user,
493 get_canonical_hostname(options.use_dns), "ssh");
Ben Lindstromf5397c02002-11-09 16:11:10 +0000494#endif
Darren Tucker2e0cf0d2005-02-08 21:52:47 +1100495#ifdef SSH_AUDIT_EVENTS
496 audit_event(SSH_INVALID_USER);
497#endif /* SSH_AUDIT_EVENTS */
Damien Miller6f0a1882002-09-22 01:26:51 +1000498 return (NULL);
499 }
500 if (!allowed_user(pw))
Ben Lindstromb481e132002-03-22 01:35:47 +0000501 return (NULL);
502#ifdef HAVE_LOGIN_CAP
503 if ((lc = login_getclass(pw->pw_class)) == NULL) {
504 debug("unable to get login class: %s", user);
505 return (NULL);
506 }
507#ifdef BSD_AUTH
508 if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 ||
Damien Miller13e35a02002-05-22 14:04:11 +1000509 auth_approval(as, lc, pw->pw_name, "ssh") <= 0) {
Ben Lindstromb481e132002-03-22 01:35:47 +0000510 debug("Approval failure for %s", user);
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000511 pw = NULL;
Ben Lindstromb481e132002-03-22 01:35:47 +0000512 }
513 if (as != NULL)
514 auth_close(as);
515#endif
516#endif
Ben Lindstromf34e4eb2002-03-22 03:08:30 +0000517 if (pw != NULL)
518 return (pwcopy(pw));
519 return (NULL);
Ben Lindstrom2ae18f42002-03-22 01:24:38 +0000520}
Ben Lindstroma574cda2002-05-15 16:16:14 +0000521
522void
523auth_debug_add(const char *fmt,...)
524{
525 char buf[1024];
526 va_list args;
527
528 if (!auth_debug_init)
529 return;
530
531 va_start(args, fmt);
532 vsnprintf(buf, sizeof(buf), fmt, args);
533 va_end(args);
534 buffer_put_cstring(&auth_debug, buf);
535}
536
537void
538auth_debug_send(void)
539{
540 char *msg;
541
542 if (!auth_debug_init)
543 return;
544 while (buffer_len(&auth_debug)) {
545 msg = buffer_get_string(&auth_debug, NULL);
546 packet_send_debug("%s", msg);
547 xfree(msg);
548 }
549}
550
551void
552auth_debug_reset(void)
553{
554 if (auth_debug_init)
555 buffer_clear(&auth_debug);
556 else {
557 buffer_init(&auth_debug);
558 auth_debug_init = 1;
559 }
560}
Damien Miller856f0be2003-09-03 07:32:45 +1000561
562struct passwd *
563fakepw(void)
564{
565 static struct passwd fake;
566
567 memset(&fake, 0, sizeof(fake));
568 fake.pw_name = "NOUSER";
569 fake.pw_passwd =
Damien Miller787b2ec2003-11-21 23:56:47 +1100570 "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK";
Damien Miller856f0be2003-09-03 07:32:45 +1000571 fake.pw_gecos = "NOUSER";
Damien Miller143c2ef2006-12-05 09:08:54 +1100572 fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid;
573 fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid;
Damien Miller856f0be2003-09-03 07:32:45 +1000574#ifdef HAVE_PW_CLASS_IN_PASSWD
575 fake.pw_class = "";
576#endif
577 fake.pw_dir = "/nonexist";
578 fake.pw_shell = "/nonexist";
579
580 return (&fake);
581}