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" |
Darren Tucker | 5cb30ad | 2004-08-12 22:40:24 +1000 | [diff] [blame] | 26 | RCSID("$OpenBSD: auth.c,v 1.56 2004/07/28 09:40:29 markus 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" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 53 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 54 | /* import */ |
| 55 | extern ServerOptions options; |
Darren Tucker | b9aa0a0 | 2003-07-08 22:59:59 +1000 | [diff] [blame] | 56 | extern Buffer loginmsg; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 57 | |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 58 | /* Debugging messages */ |
| 59 | Buffer auth_debug; |
| 60 | int auth_debug_init; |
| 61 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 62 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 63 | * Check if the user is allowed to log in via ssh. If user is listed |
| 64 | * in DenyUsers or one of user's groups is listed in DenyGroups, false |
| 65 | * will be returned. If AllowUsers isn't empty and user isn't listed |
| 66 | * there, or if AllowGroups isn't empty and one of user's groups isn't |
| 67 | * listed there, false will be returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 68 | * If the user's shell is not executable, false will be returned. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 69 | * Otherwise true is returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 70 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 71 | int |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 72 | allowed_user(struct passwd * pw) |
| 73 | { |
| 74 | struct stat st; |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 75 | const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; |
Damien Miller | e7cf07c | 2001-03-20 09:15:57 +1100 | [diff] [blame] | 76 | char *shell; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 77 | int i; |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 78 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 79 | struct spwd *spw = NULL; |
Tim Rice | 458c6bf | 2003-01-08 20:04:27 -0800 | [diff] [blame] | 80 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 81 | |
| 82 | /* 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] | 83 | if (!pw || !pw->pw_name) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 84 | return 0; |
| 85 | |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 86 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 87 | if (!options.use_pam) |
| 88 | spw = getspnam(pw->pw_name); |
| 89 | #ifdef HAS_SHADOW_EXPIRE |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 90 | if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) |
| 91 | return 0; |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 92 | #endif /* HAS_SHADOW_EXPIRE */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 93 | #endif /* USE_SHADOW */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 94 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 95 | /* grab passwd field for locked account check */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 96 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 97 | if (spw != NULL) |
| 98 | passwd = spw->sp_pwdp; |
| 99 | #else |
| 100 | passwd = pw->pw_passwd; |
Damien Miller | 06817f9 | 2003-01-07 23:55:59 +1100 | [diff] [blame] | 101 | #endif |
| 102 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 103 | /* check for locked account */ |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 104 | if (!options.use_pam && passwd && *passwd) { |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 105 | int locked = 0; |
| 106 | |
| 107 | #ifdef LOCKED_PASSWD_STRING |
| 108 | if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) |
| 109 | locked = 1; |
| 110 | #endif |
| 111 | #ifdef LOCKED_PASSWD_PREFIX |
| 112 | if (strncmp(passwd, LOCKED_PASSWD_PREFIX, |
| 113 | strlen(LOCKED_PASSWD_PREFIX)) == 0) |
| 114 | locked = 1; |
| 115 | #endif |
| 116 | #ifdef LOCKED_PASSWD_SUBSTR |
| 117 | if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) |
| 118 | locked = 1; |
| 119 | #endif |
| 120 | if (locked) { |
| 121 | logit("User %.100s not allowed because account is locked", |
| 122 | pw->pw_name); |
| 123 | return 0; |
| 124 | } |
| 125 | } |
| 126 | |
Damien Miller | ef7df54 | 2000-05-19 00:03:23 +1000 | [diff] [blame] | 127 | /* |
| 128 | * Get the shell from the password data. An empty shell field is |
| 129 | * legal, and means /bin/sh. |
| 130 | */ |
| 131 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; |
| 132 | |
| 133 | /* deny if shell does not exists or is not executable */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 134 | if (stat(shell, &st) != 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 135 | logit("User %.100s not allowed because shell %.100s does not exist", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 136 | pw->pw_name, shell); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 137 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 138 | } |
Ben Lindstrom | b61e6df | 2002-03-22 01:15:33 +0000 | [diff] [blame] | 139 | if (S_ISREG(st.st_mode) == 0 || |
| 140 | (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 141 | logit("User %.100s not allowed because shell %.100s is not executable", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 142 | pw->pw_name, shell); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 143 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 144 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 145 | |
Ben Lindstrom | 3fb5d00 | 2002-03-05 01:42:42 +0000 | [diff] [blame] | 146 | if (options.num_deny_users > 0 || options.num_allow_users > 0) { |
Damien Miller | 3a961dc | 2003-06-03 10:25:48 +1000 | [diff] [blame] | 147 | hostname = get_canonical_hostname(options.use_dns); |
Ben Lindstrom | 3fb5d00 | 2002-03-05 01:42:42 +0000 | [diff] [blame] | 148 | ipaddr = get_remote_ipaddr(); |
| 149 | } |
| 150 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 151 | /* Return false if user is listed in DenyUsers */ |
| 152 | if (options.num_deny_users > 0) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 153 | for (i = 0; i < options.num_deny_users; i++) |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 154 | if (match_user(pw->pw_name, hostname, ipaddr, |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 155 | options.deny_users[i])) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 156 | logit("User %.100s not allowed because listed in DenyUsers", |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 157 | pw->pw_name); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 158 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 159 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 160 | } |
| 161 | /* Return false if AllowUsers isn't empty and user isn't listed there */ |
| 162 | if (options.num_allow_users > 0) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 163 | for (i = 0; i < options.num_allow_users; i++) |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 164 | if (match_user(pw->pw_name, hostname, ipaddr, |
Ben Lindstrom | 6026002 | 2001-07-04 04:56:44 +0000 | [diff] [blame] | 165 | options.allow_users[i])) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 166 | break; |
| 167 | /* i < options.num_allow_users iff we break for loop */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 168 | if (i >= options.num_allow_users) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 169 | logit("User %.100s not allowed because not listed in AllowUsers", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 170 | pw->pw_name); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 171 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 172 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 173 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 174 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 175 | /* Get the user's group access list (primary and supplementary) */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 176 | if (ga_init(pw->pw_name, pw->pw_gid) == 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 177 | logit("User %.100s not allowed because not in any group", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 178 | pw->pw_name); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 179 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 180 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 181 | |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 182 | /* Return false if one of user's groups is listed in DenyGroups */ |
| 183 | if (options.num_deny_groups > 0) |
| 184 | if (ga_match(options.deny_groups, |
| 185 | options.num_deny_groups)) { |
| 186 | ga_free(); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 187 | logit("User %.100s not allowed because a group is listed in DenyGroups", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 188 | pw->pw_name); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 189 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 190 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 191 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 192 | * 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] | 193 | * isn't listed there |
| 194 | */ |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 195 | if (options.num_allow_groups > 0) |
| 196 | if (!ga_match(options.allow_groups, |
| 197 | options.num_allow_groups)) { |
| 198 | ga_free(); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 199 | logit("User %.100s not allowed because none of user's groups are listed in AllowGroups", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 200 | pw->pw_name); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 201 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 202 | } |
| 203 | ga_free(); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 204 | } |
| 205 | |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 206 | #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER |
| 207 | if (!sys_auth_allowed_user(pw)) |
| 208 | return 0; |
| 209 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 210 | |
| 211 | /* We found no reason not to let this user try to log on... */ |
| 212 | return 1; |
| 213 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 214 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 215 | void |
| 216 | auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) |
| 217 | { |
| 218 | void (*authlog) (const char *fmt,...) = verbose; |
| 219 | char *authmsg; |
| 220 | |
| 221 | /* Raise logging level */ |
| 222 | if (authenticated == 1 || |
| 223 | !authctxt->valid || |
Darren Tucker | 89413db | 2004-05-24 10:36:23 +1000 | [diff] [blame] | 224 | authctxt->failures >= options.max_authtries / 2 || |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 225 | strcmp(method, "password") == 0) |
Damien Miller | 2a3f20e | 2003-04-09 21:12:00 +1000 | [diff] [blame] | 226 | authlog = logit; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 227 | |
| 228 | if (authctxt->postponed) |
| 229 | authmsg = "Postponed"; |
| 230 | else |
| 231 | authmsg = authenticated ? "Accepted" : "Failed"; |
| 232 | |
| 233 | authlog("%s %s for %s%.100s from %.200s port %d%s", |
| 234 | authmsg, |
| 235 | method, |
Darren Tucker | 5cb30ad | 2004-08-12 22:40:24 +1000 | [diff] [blame] | 236 | authctxt->valid ? "" : "invalid user ", |
Damien Miller | f655207 | 2001-11-12 11:06:06 +1100 | [diff] [blame] | 237 | authctxt->user, |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 238 | get_remote_ipaddr(), |
| 239 | get_remote_port(), |
| 240 | info); |
Ben Lindstrom | e06eb68 | 2002-07-04 00:27:21 +0000 | [diff] [blame] | 241 | |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 242 | #ifdef CUSTOM_FAILED_LOGIN |
Ben Lindstrom | e06eb68 | 2002-07-04 00:27:21 +0000 | [diff] [blame] | 243 | if (authenticated == 0 && strcmp(method, "password") == 0) |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 244 | record_failed_login(authctxt->user, "ssh"); |
| 245 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 246 | } |
| 247 | |
| 248 | /* |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 249 | * Check whether root logins are disallowed. |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 250 | */ |
| 251 | int |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 252 | auth_root_allowed(char *method) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 253 | { |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 254 | switch (options.permit_root_login) { |
| 255 | case PERMIT_YES: |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 256 | return 1; |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 257 | break; |
| 258 | case PERMIT_NO_PASSWD: |
| 259 | if (strcmp(method, "password") != 0) |
| 260 | return 1; |
| 261 | break; |
| 262 | case PERMIT_FORCED_ONLY: |
| 263 | if (forced_command) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 264 | logit("Root login accepted for forced command."); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 265 | return 1; |
| 266 | } |
| 267 | break; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 268 | } |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 269 | logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 270 | return 0; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 271 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 272 | |
| 273 | |
| 274 | /* |
| 275 | * Given a template and a passwd structure, build a filename |
| 276 | * by substituting % tokenised options. Currently, %% becomes '%', |
| 277 | * %h becomes the home directory and %u the username. |
| 278 | * |
| 279 | * This returns a buffer allocated by xmalloc. |
| 280 | */ |
| 281 | char * |
| 282 | expand_filename(const char *filename, struct passwd *pw) |
| 283 | { |
| 284 | Buffer buffer; |
| 285 | char *file; |
| 286 | const char *cp; |
| 287 | |
| 288 | /* |
| 289 | * Build the filename string in the buffer by making the appropriate |
| 290 | * substitutions to the given file name. |
| 291 | */ |
| 292 | buffer_init(&buffer); |
| 293 | for (cp = filename; *cp; cp++) { |
| 294 | if (cp[0] == '%' && cp[1] == '%') { |
| 295 | buffer_append(&buffer, "%", 1); |
| 296 | cp++; |
| 297 | continue; |
| 298 | } |
| 299 | if (cp[0] == '%' && cp[1] == 'h') { |
| 300 | buffer_append(&buffer, pw->pw_dir, strlen(pw->pw_dir)); |
| 301 | cp++; |
| 302 | continue; |
| 303 | } |
| 304 | if (cp[0] == '%' && cp[1] == 'u') { |
| 305 | buffer_append(&buffer, pw->pw_name, |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 306 | strlen(pw->pw_name)); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 307 | cp++; |
| 308 | continue; |
| 309 | } |
| 310 | buffer_append(&buffer, cp, 1); |
| 311 | } |
| 312 | buffer_append(&buffer, "\0", 1); |
| 313 | |
| 314 | /* |
| 315 | * Ensure that filename starts anchored. If not, be backward |
| 316 | * compatible and prepend the '%h/' |
| 317 | */ |
| 318 | file = xmalloc(MAXPATHLEN); |
| 319 | cp = buffer_ptr(&buffer); |
| 320 | if (*cp != '/') |
| 321 | snprintf(file, MAXPATHLEN, "%s/%s", pw->pw_dir, cp); |
| 322 | else |
| 323 | strlcpy(file, cp, MAXPATHLEN); |
| 324 | |
| 325 | buffer_free(&buffer); |
| 326 | return file; |
| 327 | } |
| 328 | |
| 329 | char * |
| 330 | authorized_keys_file(struct passwd *pw) |
| 331 | { |
| 332 | return expand_filename(options.authorized_keys_file, pw); |
| 333 | } |
| 334 | |
| 335 | char * |
| 336 | authorized_keys_file2(struct passwd *pw) |
| 337 | { |
| 338 | return expand_filename(options.authorized_keys_file2, pw); |
| 339 | } |
| 340 | |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 341 | /* return ok if key exists in sysfile or userfile */ |
| 342 | HostStatus |
| 343 | check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, |
| 344 | const char *sysfile, const char *userfile) |
| 345 | { |
| 346 | Key *found; |
| 347 | char *user_hostfile; |
| 348 | struct stat st; |
Ben Lindstrom | 65366a8 | 2001-12-06 16:32:47 +0000 | [diff] [blame] | 349 | HostStatus host_status; |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 350 | |
| 351 | /* Check if we know the host and its host key. */ |
| 352 | found = key_new(key->type); |
| 353 | host_status = check_host_in_hostfile(sysfile, host, key, found, NULL); |
| 354 | |
| 355 | if (host_status != HOST_OK && userfile != NULL) { |
| 356 | user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); |
| 357 | if (options.strict_modes && |
| 358 | (stat(user_hostfile, &st) == 0) && |
| 359 | ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 360 | (st.st_mode & 022) != 0)) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 361 | logit("Authentication refused for %.100s: " |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 362 | "bad owner or modes for %.200s", |
| 363 | pw->pw_name, user_hostfile); |
| 364 | } else { |
| 365 | temporarily_use_uid(pw); |
| 366 | host_status = check_host_in_hostfile(user_hostfile, |
| 367 | host, key, found, NULL); |
| 368 | restore_uid(); |
| 369 | } |
| 370 | xfree(user_hostfile); |
| 371 | } |
| 372 | key_free(found); |
| 373 | |
| 374 | debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ? |
| 375 | "ok" : "not found", host); |
| 376 | return host_status; |
| 377 | } |
| 378 | |
| 379 | |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 380 | /* |
| 381 | * Check a given file for security. This is defined as all components |
Ben Lindstrom | d4ee349 | 2002-08-20 18:42:13 +0000 | [diff] [blame] | 382 | * 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] | 383 | * 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] | 384 | * |
| 385 | * XXX Should any specific check be done for sym links ? |
| 386 | * |
| 387 | * Takes an open file descriptor, the file name, a uid and and |
| 388 | * error buffer plus max size as arguments. |
| 389 | * |
| 390 | * Returns 0 on success and -1 on failure |
| 391 | */ |
| 392 | int |
Ben Lindstrom | 248c078 | 2001-07-04 03:40:39 +0000 | [diff] [blame] | 393 | secure_filename(FILE *f, const char *file, struct passwd *pw, |
| 394 | char *err, size_t errlen) |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 395 | { |
Ben Lindstrom | 248c078 | 2001-07-04 03:40:39 +0000 | [diff] [blame] | 396 | uid_t uid = pw->pw_uid; |
Ben Lindstrom | c3e49e7 | 2001-10-03 17:55:26 +0000 | [diff] [blame] | 397 | char buf[MAXPATHLEN], homedir[MAXPATHLEN]; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 398 | char *cp; |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 399 | int comparehome = 0; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 400 | struct stat st; |
| 401 | |
| 402 | if (realpath(file, buf) == NULL) { |
| 403 | snprintf(err, errlen, "realpath %s failed: %s", file, |
| 404 | strerror(errno)); |
| 405 | return -1; |
| 406 | } |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 407 | if (realpath(pw->pw_dir, homedir) != NULL) |
| 408 | comparehome = 1; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 409 | |
| 410 | /* check the open file to avoid races */ |
| 411 | if (fstat(fileno(f), &st) < 0 || |
| 412 | (st.st_uid != 0 && st.st_uid != uid) || |
| 413 | (st.st_mode & 022) != 0) { |
| 414 | snprintf(err, errlen, "bad ownership or modes for file %s", |
| 415 | buf); |
| 416 | return -1; |
| 417 | } |
| 418 | |
| 419 | /* for each component of the canonical path, walking upwards */ |
| 420 | for (;;) { |
| 421 | if ((cp = dirname(buf)) == NULL) { |
| 422 | snprintf(err, errlen, "dirname() failed"); |
| 423 | return -1; |
| 424 | } |
| 425 | strlcpy(buf, cp, sizeof(buf)); |
| 426 | |
| 427 | debug3("secure_filename: checking '%s'", buf); |
| 428 | if (stat(buf, &st) < 0 || |
| 429 | (st.st_uid != 0 && st.st_uid != uid) || |
| 430 | (st.st_mode & 022) != 0) { |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 431 | snprintf(err, errlen, |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 432 | "bad ownership or modes for directory %s", buf); |
| 433 | return -1; |
| 434 | } |
| 435 | |
Damien Miller | 0ae6e00 | 2001-07-14 12:21:34 +1000 | [diff] [blame] | 436 | /* If are passed the homedir then we can stop */ |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 437 | if (comparehome && strcmp(homedir, buf) == 0) { |
Damien Miller | 0ae6e00 | 2001-07-14 12:21:34 +1000 | [diff] [blame] | 438 | debug3("secure_filename: terminating check at '%s'", |
| 439 | buf); |
| 440 | break; |
| 441 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 442 | /* |
| 443 | * dirname should always complete with a "/" path, |
| 444 | * but we can be paranoid and check for "." too |
| 445 | */ |
| 446 | if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) |
| 447 | break; |
| 448 | } |
| 449 | return 0; |
| 450 | } |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 451 | |
| 452 | struct passwd * |
| 453 | getpwnamallow(const char *user) |
| 454 | { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 455 | #ifdef HAVE_LOGIN_CAP |
| 456 | extern login_cap_t *lc; |
| 457 | #ifdef BSD_AUTH |
| 458 | auth_session_t *as; |
| 459 | #endif |
| 460 | #endif |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 461 | struct passwd *pw; |
| 462 | |
| 463 | pw = getpwnam(user); |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 464 | if (pw == NULL) { |
Damien Miller | a22f2d7 | 2004-07-21 20:48:24 +1000 | [diff] [blame] | 465 | logit("Invalid user %.100s from %.100s", |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 466 | user, get_remote_ipaddr()); |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 467 | #ifdef CUSTOM_FAILED_LOGIN |
| 468 | record_failed_login(user, "ssh"); |
Ben Lindstrom | f5397c0 | 2002-11-09 16:11:10 +0000 | [diff] [blame] | 469 | #endif |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 470 | return (NULL); |
| 471 | } |
| 472 | if (!allowed_user(pw)) |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 473 | return (NULL); |
| 474 | #ifdef HAVE_LOGIN_CAP |
| 475 | if ((lc = login_getclass(pw->pw_class)) == NULL) { |
| 476 | debug("unable to get login class: %s", user); |
| 477 | return (NULL); |
| 478 | } |
| 479 | #ifdef BSD_AUTH |
| 480 | if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || |
Damien Miller | 13e35a0 | 2002-05-22 14:04:11 +1000 | [diff] [blame] | 481 | auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 482 | debug("Approval failure for %s", user); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 483 | pw = NULL; |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 484 | } |
| 485 | if (as != NULL) |
| 486 | auth_close(as); |
| 487 | #endif |
| 488 | #endif |
Ben Lindstrom | f34e4eb | 2002-03-22 03:08:30 +0000 | [diff] [blame] | 489 | if (pw != NULL) |
| 490 | return (pwcopy(pw)); |
| 491 | return (NULL); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 492 | } |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 493 | |
| 494 | void |
| 495 | auth_debug_add(const char *fmt,...) |
| 496 | { |
| 497 | char buf[1024]; |
| 498 | va_list args; |
| 499 | |
| 500 | if (!auth_debug_init) |
| 501 | return; |
| 502 | |
| 503 | va_start(args, fmt); |
| 504 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 505 | va_end(args); |
| 506 | buffer_put_cstring(&auth_debug, buf); |
| 507 | } |
| 508 | |
| 509 | void |
| 510 | auth_debug_send(void) |
| 511 | { |
| 512 | char *msg; |
| 513 | |
| 514 | if (!auth_debug_init) |
| 515 | return; |
| 516 | while (buffer_len(&auth_debug)) { |
| 517 | msg = buffer_get_string(&auth_debug, NULL); |
| 518 | packet_send_debug("%s", msg); |
| 519 | xfree(msg); |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | void |
| 524 | auth_debug_reset(void) |
| 525 | { |
| 526 | if (auth_debug_init) |
| 527 | buffer_clear(&auth_debug); |
| 528 | else { |
| 529 | buffer_init(&auth_debug); |
| 530 | auth_debug_init = 1; |
| 531 | } |
| 532 | } |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 533 | |
| 534 | struct passwd * |
| 535 | fakepw(void) |
| 536 | { |
| 537 | static struct passwd fake; |
| 538 | |
| 539 | memset(&fake, 0, sizeof(fake)); |
| 540 | fake.pw_name = "NOUSER"; |
| 541 | fake.pw_passwd = |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 542 | "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 543 | fake.pw_gecos = "NOUSER"; |
Darren Tucker | 1f8311c | 2004-05-13 16:39:33 +1000 | [diff] [blame] | 544 | fake.pw_uid = (uid_t)-1; |
| 545 | fake.pw_gid = (gid_t)-1; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 546 | #ifdef HAVE_PW_CLASS_IN_PASSWD |
| 547 | fake.pw_class = ""; |
| 548 | #endif |
| 549 | fake.pw_dir = "/nonexist"; |
| 550 | fake.pw_shell = "/nonexist"; |
| 551 | |
| 552 | return (&fake); |
| 553 | } |