Damien Miller | 116e6df | 2002-05-22 15:06:28 +1000 | [diff] [blame] | 1 | /* |
Ben Lindstrom | 92a2e38 | 2001-03-05 06:59:27 +0000 | [diff] [blame] | 2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * 1. Redistributions of source code must retain the above copyright |
| 8 | * notice, this list of conditions and the following disclaimer. |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer in the |
| 11 | * documentation and/or other materials provided with the distribution. |
| 12 | * |
| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 23 | */ |
| 24 | |
| 25 | #include "includes.h" |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 26 | RCSID("$OpenBSD: auth.c,v 1.59 2005/06/06 11:20:36 djm Exp $"); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 27 | |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 28 | #ifdef HAVE_LOGIN_H |
| 29 | #include <login.h> |
| 30 | #endif |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 31 | #ifdef USE_SHADOW |
Damien Miller | 1f335fb | 2000-06-26 11:31:33 +1000 | [diff] [blame] | 32 | #include <shadow.h> |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 33 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 34 | |
Ben Lindstrom | 68c3ce1 | 2001-06-10 17:24:51 +0000 | [diff] [blame] | 35 | #ifdef HAVE_LIBGEN_H |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 36 | #include <libgen.h> |
Ben Lindstrom | 68c3ce1 | 2001-06-10 17:24:51 +0000 | [diff] [blame] | 37 | #endif |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 38 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 39 | #include "xmalloc.h" |
| 40 | #include "match.h" |
| 41 | #include "groupaccess.h" |
| 42 | #include "log.h" |
| 43 | #include "servconf.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 44 | #include "auth.h" |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 45 | #include "auth-options.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 46 | #include "canohost.h" |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 47 | #include "buffer.h" |
| 48 | #include "bufaux.h" |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 49 | #include "uidswap.h" |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 50 | #include "misc.h" |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 51 | #include "bufaux.h" |
| 52 | #include "packet.h" |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 53 | #include "loginrec.h" |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 54 | #include "monitor_wrap.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 55 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 56 | /* import */ |
| 57 | extern ServerOptions options; |
Darren Tucker | b9aa0a0 | 2003-07-08 22:59:59 +1000 | [diff] [blame] | 58 | extern Buffer loginmsg; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 59 | |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 60 | /* Debugging messages */ |
| 61 | Buffer auth_debug; |
| 62 | int auth_debug_init; |
| 63 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 64 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 65 | * Check if the user is allowed to log in via ssh. If user is listed |
| 66 | * in DenyUsers or one of user's groups is listed in DenyGroups, false |
| 67 | * will be returned. If AllowUsers isn't empty and user isn't listed |
| 68 | * there, or if AllowGroups isn't empty and one of user's groups isn't |
| 69 | * listed there, false will be returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 70 | * If the user's shell is not executable, false will be returned. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 71 | * Otherwise true is returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 72 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 73 | int |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 74 | allowed_user(struct passwd * pw) |
| 75 | { |
| 76 | struct stat st; |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 77 | const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; |
Damien Miller | e7cf07c | 2001-03-20 09:15:57 +1100 | [diff] [blame] | 78 | char *shell; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 79 | int i; |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 80 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 81 | struct spwd *spw = NULL; |
Tim Rice | 458c6bf | 2003-01-08 20:04:27 -0800 | [diff] [blame] | 82 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 83 | |
| 84 | /* Shouldn't be called if pw is NULL, but better safe than sorry... */ |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 85 | if (!pw || !pw->pw_name) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 86 | return 0; |
| 87 | |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 88 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 89 | if (!options.use_pam) |
| 90 | spw = getspnam(pw->pw_name); |
| 91 | #ifdef HAS_SHADOW_EXPIRE |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 92 | if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) |
| 93 | return 0; |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 94 | #endif /* HAS_SHADOW_EXPIRE */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 95 | #endif /* USE_SHADOW */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 96 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 97 | /* grab passwd field for locked account check */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 98 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 99 | if (spw != NULL) |
| 100 | passwd = spw->sp_pwdp; |
| 101 | #else |
| 102 | passwd = pw->pw_passwd; |
Damien Miller | 06817f9 | 2003-01-07 23:55:59 +1100 | [diff] [blame] | 103 | #endif |
| 104 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 105 | /* check for locked account */ |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 106 | if (!options.use_pam && passwd && *passwd) { |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 107 | int locked = 0; |
| 108 | |
| 109 | #ifdef LOCKED_PASSWD_STRING |
| 110 | if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) |
| 111 | locked = 1; |
| 112 | #endif |
| 113 | #ifdef LOCKED_PASSWD_PREFIX |
| 114 | if (strncmp(passwd, LOCKED_PASSWD_PREFIX, |
| 115 | strlen(LOCKED_PASSWD_PREFIX)) == 0) |
| 116 | locked = 1; |
| 117 | #endif |
| 118 | #ifdef LOCKED_PASSWD_SUBSTR |
| 119 | if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) |
| 120 | locked = 1; |
| 121 | #endif |
| 122 | if (locked) { |
| 123 | logit("User %.100s not allowed because account is locked", |
| 124 | pw->pw_name); |
| 125 | return 0; |
| 126 | } |
| 127 | } |
| 128 | |
Damien Miller | ef7df54 | 2000-05-19 00:03:23 +1000 | [diff] [blame] | 129 | /* |
| 130 | * Get the shell from the password data. An empty shell field is |
| 131 | * legal, and means /bin/sh. |
| 132 | */ |
| 133 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; |
| 134 | |
| 135 | /* deny if shell does not exists or is not executable */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 136 | if (stat(shell, &st) != 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 137 | logit("User %.100s not allowed because shell %.100s does not exist", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 138 | pw->pw_name, shell); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 139 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 140 | } |
Ben Lindstrom | b61e6df | 2002-03-22 01:15:33 +0000 | [diff] [blame] | 141 | if (S_ISREG(st.st_mode) == 0 || |
| 142 | (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 143 | logit("User %.100s not allowed because shell %.100s is not executable", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 144 | pw->pw_name, shell); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 145 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 146 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 147 | |
Darren Tucker | a8f553d | 2005-03-14 23:17:27 +1100 | [diff] [blame] | 148 | if (options.num_deny_users > 0 || options.num_allow_users > 0 || |
| 149 | options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
Damien Miller | 3a961dc | 2003-06-03 10:25:48 +1000 | [diff] [blame] | 150 | hostname = get_canonical_hostname(options.use_dns); |
Ben Lindstrom | 3fb5d00 | 2002-03-05 01:42:42 +0000 | [diff] [blame] | 151 | ipaddr = get_remote_ipaddr(); |
| 152 | } |
| 153 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 154 | /* Return false if user is listed in DenyUsers */ |
| 155 | if (options.num_deny_users > 0) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 156 | for (i = 0; i < options.num_deny_users; i++) |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 157 | if (match_user(pw->pw_name, hostname, ipaddr, |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 158 | options.deny_users[i])) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 159 | logit("User %.100s from %.100s not allowed " |
| 160 | "because listed in DenyUsers", |
| 161 | pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 162 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 163 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 164 | } |
| 165 | /* Return false if AllowUsers isn't empty and user isn't listed there */ |
| 166 | if (options.num_allow_users > 0) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 167 | for (i = 0; i < options.num_allow_users; i++) |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 168 | if (match_user(pw->pw_name, hostname, ipaddr, |
Ben Lindstrom | 6026002 | 2001-07-04 04:56:44 +0000 | [diff] [blame] | 169 | options.allow_users[i])) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 170 | break; |
| 171 | /* i < options.num_allow_users iff we break for loop */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 172 | if (i >= options.num_allow_users) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 173 | logit("User %.100s from %.100s not allowed because " |
| 174 | "not listed in AllowUsers", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 175 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 176 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 177 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 178 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 179 | /* Get the user's group access list (primary and supplementary) */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 180 | if (ga_init(pw->pw_name, pw->pw_gid) == 0) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 181 | logit("User %.100s from %.100s not allowed because " |
| 182 | "not in any group", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 183 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 184 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 185 | |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 186 | /* Return false if one of user's groups is listed in DenyGroups */ |
| 187 | if (options.num_deny_groups > 0) |
| 188 | if (ga_match(options.deny_groups, |
| 189 | options.num_deny_groups)) { |
| 190 | ga_free(); |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 191 | logit("User %.100s from %.100s not allowed " |
| 192 | "because a group is listed in DenyGroups", |
| 193 | pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 194 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 195 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 196 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 197 | * Return false if AllowGroups isn't empty and one of user's groups |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 198 | * isn't listed there |
| 199 | */ |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 200 | if (options.num_allow_groups > 0) |
| 201 | if (!ga_match(options.allow_groups, |
| 202 | options.num_allow_groups)) { |
| 203 | ga_free(); |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 204 | logit("User %.100s from %.100s not allowed " |
| 205 | "because none of user's groups are listed " |
| 206 | "in AllowGroups", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 207 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 208 | } |
| 209 | ga_free(); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 210 | } |
| 211 | |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 212 | #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER |
Darren Tucker | 691d523 | 2005-02-15 21:45:57 +1100 | [diff] [blame] | 213 | if (!sys_auth_allowed_user(pw, &loginmsg)) |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 214 | return 0; |
| 215 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 216 | |
| 217 | /* We found no reason not to let this user try to log on... */ |
| 218 | return 1; |
| 219 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 220 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 221 | void |
| 222 | auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) |
| 223 | { |
| 224 | void (*authlog) (const char *fmt,...) = verbose; |
| 225 | char *authmsg; |
| 226 | |
| 227 | /* Raise logging level */ |
| 228 | if (authenticated == 1 || |
| 229 | !authctxt->valid || |
Darren Tucker | 89413db | 2004-05-24 10:36:23 +1000 | [diff] [blame] | 230 | authctxt->failures >= options.max_authtries / 2 || |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 231 | strcmp(method, "password") == 0) |
Damien Miller | 2a3f20e | 2003-04-09 21:12:00 +1000 | [diff] [blame] | 232 | authlog = logit; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 233 | |
| 234 | if (authctxt->postponed) |
| 235 | authmsg = "Postponed"; |
| 236 | else |
| 237 | authmsg = authenticated ? "Accepted" : "Failed"; |
| 238 | |
| 239 | authlog("%s %s for %s%.100s from %.200s port %d%s", |
| 240 | authmsg, |
| 241 | method, |
Darren Tucker | 5cb30ad | 2004-08-12 22:40:24 +1000 | [diff] [blame] | 242 | authctxt->valid ? "" : "invalid user ", |
Damien Miller | f655207 | 2001-11-12 11:06:06 +1100 | [diff] [blame] | 243 | authctxt->user, |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 244 | get_remote_ipaddr(), |
| 245 | get_remote_port(), |
| 246 | info); |
Ben Lindstrom | e06eb68 | 2002-07-04 00:27:21 +0000 | [diff] [blame] | 247 | |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 248 | #ifdef CUSTOM_FAILED_LOGIN |
Darren Tucker | 2fba993 | 2005-02-02 23:30:24 +1100 | [diff] [blame] | 249 | if (authenticated == 0 && !authctxt->postponed && |
| 250 | (strcmp(method, "password") == 0 || |
Darren Tucker | 40d9a63 | 2005-02-04 15:19:44 +1100 | [diff] [blame] | 251 | strncmp(method, "keyboard-interactive", 20) == 0 || |
| 252 | strcmp(method, "challenge-response") == 0)) |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 253 | record_failed_login(authctxt->user, |
| 254 | get_canonical_hostname(options.use_dns), "ssh"); |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 255 | #endif |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 256 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 257 | if (authenticated == 0 && !authctxt->postponed) { |
| 258 | ssh_audit_event_t event; |
| 259 | |
| 260 | debug3("audit failed auth attempt, method %s euid %d", |
| 261 | method, (int)geteuid()); |
| 262 | /* |
| 263 | * Because the auth loop is used in both monitor and slave, |
| 264 | * we must be careful to send each event only once and with |
| 265 | * enough privs to write the event. |
| 266 | */ |
| 267 | event = audit_classify_auth(method); |
| 268 | switch(event) { |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 269 | case SSH_AUTH_FAIL_NONE: |
| 270 | case SSH_AUTH_FAIL_PASSWD: |
| 271 | case SSH_AUTH_FAIL_KBDINT: |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 272 | if (geteuid() == 0) |
| 273 | audit_event(event); |
| 274 | break; |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 275 | case SSH_AUTH_FAIL_PUBKEY: |
| 276 | case SSH_AUTH_FAIL_HOSTBASED: |
| 277 | case SSH_AUTH_FAIL_GSSAPI: |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 278 | /* |
| 279 | * This is required to handle the case where privsep |
| 280 | * is enabled but it's root logging in, since |
| 281 | * use_privsep won't be cleared until after a |
| 282 | * successful login. |
| 283 | */ |
| 284 | if (geteuid() == 0) |
| 285 | audit_event(event); |
| 286 | else |
| 287 | PRIVSEP(audit_event(event)); |
| 288 | break; |
| 289 | default: |
| 290 | error("unknown authentication audit event %d", event); |
| 291 | } |
| 292 | } |
| 293 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 294 | } |
| 295 | |
| 296 | /* |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 297 | * Check whether root logins are disallowed. |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 298 | */ |
| 299 | int |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 300 | auth_root_allowed(char *method) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 301 | { |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 302 | switch (options.permit_root_login) { |
| 303 | case PERMIT_YES: |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 304 | return 1; |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 305 | break; |
| 306 | case PERMIT_NO_PASSWD: |
| 307 | if (strcmp(method, "password") != 0) |
| 308 | return 1; |
| 309 | break; |
| 310 | case PERMIT_FORCED_ONLY: |
| 311 | if (forced_command) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 312 | logit("Root login accepted for forced command."); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 313 | return 1; |
| 314 | } |
| 315 | break; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 316 | } |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 317 | logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 318 | return 0; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 319 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 320 | |
| 321 | |
| 322 | /* |
| 323 | * Given a template and a passwd structure, build a filename |
| 324 | * by substituting % tokenised options. Currently, %% becomes '%', |
| 325 | * %h becomes the home directory and %u the username. |
| 326 | * |
| 327 | * This returns a buffer allocated by xmalloc. |
| 328 | */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 329 | static char * |
| 330 | expand_authorized_keys(const char *filename, struct passwd *pw) |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 331 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 332 | char *file, *ret; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 333 | |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 334 | file = percent_expand(filename, "h", pw->pw_dir, |
| 335 | "u", pw->pw_name, (char *)NULL); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 336 | |
| 337 | /* |
| 338 | * Ensure that filename starts anchored. If not, be backward |
| 339 | * compatible and prepend the '%h/' |
| 340 | */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 341 | if (*file == '/') |
| 342 | return (file); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 343 | |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 344 | ret = xmalloc(MAXPATHLEN); |
| 345 | if (strlcpy(ret, pw->pw_dir, MAXPATHLEN) >= MAXPATHLEN || |
| 346 | strlcat(ret, "/", MAXPATHLEN) >= MAXPATHLEN || |
| 347 | strlcat(ret, file, MAXPATHLEN) >= MAXPATHLEN) |
| 348 | fatal("expand_authorized_keys: path too long"); |
| 349 | |
| 350 | xfree(file); |
| 351 | return (ret); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 352 | } |
| 353 | |
| 354 | char * |
| 355 | authorized_keys_file(struct passwd *pw) |
| 356 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 357 | return expand_authorized_keys(options.authorized_keys_file, pw); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 358 | } |
| 359 | |
| 360 | char * |
| 361 | authorized_keys_file2(struct passwd *pw) |
| 362 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 363 | return expand_authorized_keys(options.authorized_keys_file2, pw); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 364 | } |
| 365 | |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 366 | /* return ok if key exists in sysfile or userfile */ |
| 367 | HostStatus |
| 368 | check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, |
| 369 | const char *sysfile, const char *userfile) |
| 370 | { |
| 371 | Key *found; |
| 372 | char *user_hostfile; |
| 373 | struct stat st; |
Ben Lindstrom | 65366a8 | 2001-12-06 16:32:47 +0000 | [diff] [blame] | 374 | HostStatus host_status; |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 375 | |
| 376 | /* Check if we know the host and its host key. */ |
| 377 | found = key_new(key->type); |
| 378 | host_status = check_host_in_hostfile(sysfile, host, key, found, NULL); |
| 379 | |
| 380 | if (host_status != HOST_OK && userfile != NULL) { |
| 381 | user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); |
| 382 | if (options.strict_modes && |
| 383 | (stat(user_hostfile, &st) == 0) && |
| 384 | ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 385 | (st.st_mode & 022) != 0)) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 386 | logit("Authentication refused for %.100s: " |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 387 | "bad owner or modes for %.200s", |
| 388 | pw->pw_name, user_hostfile); |
| 389 | } else { |
| 390 | temporarily_use_uid(pw); |
| 391 | host_status = check_host_in_hostfile(user_hostfile, |
| 392 | host, key, found, NULL); |
| 393 | restore_uid(); |
| 394 | } |
| 395 | xfree(user_hostfile); |
| 396 | } |
| 397 | key_free(found); |
| 398 | |
| 399 | debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ? |
| 400 | "ok" : "not found", host); |
| 401 | return host_status; |
| 402 | } |
| 403 | |
| 404 | |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 405 | /* |
| 406 | * Check a given file for security. This is defined as all components |
Ben Lindstrom | d4ee349 | 2002-08-20 18:42:13 +0000 | [diff] [blame] | 407 | * of the path to the file must be owned by either the owner of |
Ben Lindstrom | 60567ff | 2001-06-05 20:27:53 +0000 | [diff] [blame] | 408 | * of the file or root and no directories must be group or world writable. |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 409 | * |
| 410 | * XXX Should any specific check be done for sym links ? |
| 411 | * |
| 412 | * Takes an open file descriptor, the file name, a uid and and |
| 413 | * error buffer plus max size as arguments. |
| 414 | * |
| 415 | * Returns 0 on success and -1 on failure |
| 416 | */ |
| 417 | int |
Ben Lindstrom | 248c078 | 2001-07-04 03:40:39 +0000 | [diff] [blame] | 418 | secure_filename(FILE *f, const char *file, struct passwd *pw, |
| 419 | char *err, size_t errlen) |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 420 | { |
Ben Lindstrom | 248c078 | 2001-07-04 03:40:39 +0000 | [diff] [blame] | 421 | uid_t uid = pw->pw_uid; |
Ben Lindstrom | c3e49e7 | 2001-10-03 17:55:26 +0000 | [diff] [blame] | 422 | char buf[MAXPATHLEN], homedir[MAXPATHLEN]; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 423 | char *cp; |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 424 | int comparehome = 0; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 425 | struct stat st; |
| 426 | |
| 427 | if (realpath(file, buf) == NULL) { |
| 428 | snprintf(err, errlen, "realpath %s failed: %s", file, |
| 429 | strerror(errno)); |
| 430 | return -1; |
| 431 | } |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 432 | if (realpath(pw->pw_dir, homedir) != NULL) |
| 433 | comparehome = 1; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 434 | |
| 435 | /* check the open file to avoid races */ |
| 436 | if (fstat(fileno(f), &st) < 0 || |
| 437 | (st.st_uid != 0 && st.st_uid != uid) || |
| 438 | (st.st_mode & 022) != 0) { |
| 439 | snprintf(err, errlen, "bad ownership or modes for file %s", |
| 440 | buf); |
| 441 | return -1; |
| 442 | } |
| 443 | |
| 444 | /* for each component of the canonical path, walking upwards */ |
| 445 | for (;;) { |
| 446 | if ((cp = dirname(buf)) == NULL) { |
| 447 | snprintf(err, errlen, "dirname() failed"); |
| 448 | return -1; |
| 449 | } |
| 450 | strlcpy(buf, cp, sizeof(buf)); |
| 451 | |
| 452 | debug3("secure_filename: checking '%s'", buf); |
| 453 | if (stat(buf, &st) < 0 || |
| 454 | (st.st_uid != 0 && st.st_uid != uid) || |
| 455 | (st.st_mode & 022) != 0) { |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 456 | snprintf(err, errlen, |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 457 | "bad ownership or modes for directory %s", buf); |
| 458 | return -1; |
| 459 | } |
| 460 | |
Damien Miller | 0ae6e00 | 2001-07-14 12:21:34 +1000 | [diff] [blame] | 461 | /* If are passed the homedir then we can stop */ |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 462 | if (comparehome && strcmp(homedir, buf) == 0) { |
Damien Miller | 0ae6e00 | 2001-07-14 12:21:34 +1000 | [diff] [blame] | 463 | debug3("secure_filename: terminating check at '%s'", |
| 464 | buf); |
| 465 | break; |
| 466 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 467 | /* |
| 468 | * dirname should always complete with a "/" path, |
| 469 | * but we can be paranoid and check for "." too |
| 470 | */ |
| 471 | if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) |
| 472 | break; |
| 473 | } |
| 474 | return 0; |
| 475 | } |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 476 | |
| 477 | struct passwd * |
| 478 | getpwnamallow(const char *user) |
| 479 | { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 480 | #ifdef HAVE_LOGIN_CAP |
| 481 | extern login_cap_t *lc; |
| 482 | #ifdef BSD_AUTH |
| 483 | auth_session_t *as; |
| 484 | #endif |
| 485 | #endif |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 486 | struct passwd *pw; |
| 487 | |
| 488 | pw = getpwnam(user); |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 489 | if (pw == NULL) { |
Damien Miller | a22f2d7 | 2004-07-21 20:48:24 +1000 | [diff] [blame] | 490 | logit("Invalid user %.100s from %.100s", |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 491 | user, get_remote_ipaddr()); |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 492 | #ifdef CUSTOM_FAILED_LOGIN |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 493 | record_failed_login(user, |
| 494 | get_canonical_hostname(options.use_dns), "ssh"); |
Ben Lindstrom | f5397c0 | 2002-11-09 16:11:10 +0000 | [diff] [blame] | 495 | #endif |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 496 | #ifdef SSH_AUDIT_EVENTS |
| 497 | audit_event(SSH_INVALID_USER); |
| 498 | #endif /* SSH_AUDIT_EVENTS */ |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 499 | return (NULL); |
| 500 | } |
| 501 | if (!allowed_user(pw)) |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 502 | return (NULL); |
| 503 | #ifdef HAVE_LOGIN_CAP |
| 504 | if ((lc = login_getclass(pw->pw_class)) == NULL) { |
| 505 | debug("unable to get login class: %s", user); |
| 506 | return (NULL); |
| 507 | } |
| 508 | #ifdef BSD_AUTH |
| 509 | if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || |
Damien Miller | 13e35a0 | 2002-05-22 14:04:11 +1000 | [diff] [blame] | 510 | auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 511 | debug("Approval failure for %s", user); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 512 | pw = NULL; |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 513 | } |
| 514 | if (as != NULL) |
| 515 | auth_close(as); |
| 516 | #endif |
| 517 | #endif |
Ben Lindstrom | f34e4eb | 2002-03-22 03:08:30 +0000 | [diff] [blame] | 518 | if (pw != NULL) |
| 519 | return (pwcopy(pw)); |
| 520 | return (NULL); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 521 | } |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 522 | |
| 523 | void |
| 524 | auth_debug_add(const char *fmt,...) |
| 525 | { |
| 526 | char buf[1024]; |
| 527 | va_list args; |
| 528 | |
| 529 | if (!auth_debug_init) |
| 530 | return; |
| 531 | |
| 532 | va_start(args, fmt); |
| 533 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 534 | va_end(args); |
| 535 | buffer_put_cstring(&auth_debug, buf); |
| 536 | } |
| 537 | |
| 538 | void |
| 539 | auth_debug_send(void) |
| 540 | { |
| 541 | char *msg; |
| 542 | |
| 543 | if (!auth_debug_init) |
| 544 | return; |
| 545 | while (buffer_len(&auth_debug)) { |
| 546 | msg = buffer_get_string(&auth_debug, NULL); |
| 547 | packet_send_debug("%s", msg); |
| 548 | xfree(msg); |
| 549 | } |
| 550 | } |
| 551 | |
| 552 | void |
| 553 | auth_debug_reset(void) |
| 554 | { |
| 555 | if (auth_debug_init) |
| 556 | buffer_clear(&auth_debug); |
| 557 | else { |
| 558 | buffer_init(&auth_debug); |
| 559 | auth_debug_init = 1; |
| 560 | } |
| 561 | } |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 562 | |
| 563 | struct passwd * |
| 564 | fakepw(void) |
| 565 | { |
| 566 | static struct passwd fake; |
| 567 | |
| 568 | memset(&fake, 0, sizeof(fake)); |
| 569 | fake.pw_name = "NOUSER"; |
| 570 | fake.pw_passwd = |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 571 | "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 572 | fake.pw_gecos = "NOUSER"; |
Darren Tucker | 1f8311c | 2004-05-13 16:39:33 +1000 | [diff] [blame] | 573 | fake.pw_uid = (uid_t)-1; |
| 574 | fake.pw_gid = (gid_t)-1; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 575 | #ifdef HAVE_PW_CLASS_IN_PASSWD |
| 576 | fake.pw_class = ""; |
| 577 | #endif |
| 578 | fake.pw_dir = "/nonexist"; |
| 579 | fake.pw_shell = "/nonexist"; |
| 580 | |
| 581 | return (&fake); |
| 582 | } |