Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 1 | /* $OpenBSD: auth.c,v 1.72 2006/07/22 20:48:22 stevesk Exp $ */ |
Damien Miller | 116e6df | 2002-05-22 15:06:28 +1000 | [diff] [blame] | 2 | /* |
Ben Lindstrom | 92a2e38 | 2001-03-05 06:59:27 +0000 | [diff] [blame] | 3 | * Copyright (c) 2000 Markus Friedl. All rights reserved. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 24 | */ |
| 25 | |
| 26 | #include "includes.h" |
Damien Miller | f17883e | 2006-03-15 11:45:54 +1100 | [diff] [blame] | 27 | |
| 28 | #include <sys/types.h> |
| 29 | #include <sys/stat.h> |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 30 | |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 31 | #include <errno.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 32 | #ifdef HAVE_PATHS_H |
Damien Miller | a9263d0 | 2006-03-15 11:18:26 +1100 | [diff] [blame] | 33 | # include <paths.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 34 | #endif |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 35 | #include <pwd.h> |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 36 | #ifdef HAVE_LOGIN_H |
| 37 | #include <login.h> |
| 38 | #endif |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 39 | #ifdef USE_SHADOW |
Damien Miller | 1f335fb | 2000-06-26 11:31:33 +1000 | [diff] [blame] | 40 | #include <shadow.h> |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 41 | #endif |
Ben Lindstrom | 68c3ce1 | 2001-06-10 17:24:51 +0000 | [diff] [blame] | 42 | #ifdef HAVE_LIBGEN_H |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 43 | #include <libgen.h> |
Ben Lindstrom | 68c3ce1 | 2001-06-10 17:24:51 +0000 | [diff] [blame] | 44 | #endif |
Darren Tucker | 5d19626 | 2006-07-12 22:15:16 +1000 | [diff] [blame] | 45 | #include <stdarg.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 46 | #include <string.h> |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 47 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 48 | #include "xmalloc.h" |
| 49 | #include "match.h" |
| 50 | #include "groupaccess.h" |
| 51 | #include "log.h" |
| 52 | #include "servconf.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 53 | #include "auth.h" |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 54 | #include "auth-options.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 55 | #include "canohost.h" |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 56 | #include "buffer.h" |
| 57 | #include "bufaux.h" |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 58 | #include "uidswap.h" |
Ben Lindstrom | 7ebb635 | 2002-03-22 03:04:08 +0000 | [diff] [blame] | 59 | #include "misc.h" |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 60 | #include "bufaux.h" |
| 61 | #include "packet.h" |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 62 | #include "loginrec.h" |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 63 | #include "monitor_wrap.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 64 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 65 | /* import */ |
| 66 | extern ServerOptions options; |
Damien Miller | 7a8f5b3 | 2006-03-31 23:14:23 +1100 | [diff] [blame] | 67 | extern int use_privsep; |
Darren Tucker | b9aa0a0 | 2003-07-08 22:59:59 +1000 | [diff] [blame] | 68 | extern Buffer loginmsg; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 69 | |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 70 | /* Debugging messages */ |
| 71 | Buffer auth_debug; |
| 72 | int auth_debug_init; |
| 73 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 74 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 75 | * Check if the user is allowed to log in via ssh. If user is listed |
| 76 | * in DenyUsers or one of user's groups is listed in DenyGroups, false |
| 77 | * will be returned. If AllowUsers isn't empty and user isn't listed |
| 78 | * there, or if AllowGroups isn't empty and one of user's groups isn't |
| 79 | * listed there, false will be returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 80 | * If the user's shell is not executable, false will be returned. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 81 | * Otherwise true is returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 82 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 83 | int |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 84 | allowed_user(struct passwd * pw) |
| 85 | { |
| 86 | struct stat st; |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 87 | const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; |
Damien Miller | e7cf07c | 2001-03-20 09:15:57 +1100 | [diff] [blame] | 88 | char *shell; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 89 | u_int i; |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 90 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 91 | struct spwd *spw = NULL; |
Tim Rice | 458c6bf | 2003-01-08 20:04:27 -0800 | [diff] [blame] | 92 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 93 | |
| 94 | /* 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] | 95 | if (!pw || !pw->pw_name) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 96 | return 0; |
| 97 | |
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 (!options.use_pam) |
| 100 | spw = getspnam(pw->pw_name); |
| 101 | #ifdef HAS_SHADOW_EXPIRE |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 102 | if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) |
| 103 | return 0; |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 104 | #endif /* HAS_SHADOW_EXPIRE */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 105 | #endif /* USE_SHADOW */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 106 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 107 | /* grab passwd field for locked account check */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 108 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 109 | if (spw != NULL) |
Tim Rice | 66fd217 | 2005-08-31 09:59:49 -0700 | [diff] [blame] | 110 | #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF) |
Tim Rice | 2291c00 | 2005-08-26 13:15:19 -0700 | [diff] [blame] | 111 | passwd = get_iaf_password(pw); |
| 112 | #else |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 113 | passwd = spw->sp_pwdp; |
Tim Rice | 66fd217 | 2005-08-31 09:59:49 -0700 | [diff] [blame] | 114 | #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 115 | #else |
| 116 | passwd = pw->pw_passwd; |
Damien Miller | 06817f9 | 2003-01-07 23:55:59 +1100 | [diff] [blame] | 117 | #endif |
| 118 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 119 | /* check for locked account */ |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 120 | if (!options.use_pam && passwd && *passwd) { |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 121 | int locked = 0; |
| 122 | |
| 123 | #ifdef LOCKED_PASSWD_STRING |
| 124 | if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) |
| 125 | locked = 1; |
| 126 | #endif |
| 127 | #ifdef LOCKED_PASSWD_PREFIX |
| 128 | if (strncmp(passwd, LOCKED_PASSWD_PREFIX, |
| 129 | strlen(LOCKED_PASSWD_PREFIX)) == 0) |
| 130 | locked = 1; |
| 131 | #endif |
| 132 | #ifdef LOCKED_PASSWD_SUBSTR |
| 133 | if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) |
| 134 | locked = 1; |
| 135 | #endif |
Tim Rice | 66fd217 | 2005-08-31 09:59:49 -0700 | [diff] [blame] | 136 | #if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF) |
| 137 | free(passwd); |
| 138 | #endif /* HAVE_LIBIAF && !BROKEN_LIBIAF */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 139 | if (locked) { |
| 140 | logit("User %.100s not allowed because account is locked", |
| 141 | pw->pw_name); |
| 142 | return 0; |
| 143 | } |
| 144 | } |
| 145 | |
Damien Miller | ef7df54 | 2000-05-19 00:03:23 +1000 | [diff] [blame] | 146 | /* |
| 147 | * Get the shell from the password data. An empty shell field is |
| 148 | * legal, and means /bin/sh. |
| 149 | */ |
| 150 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; |
| 151 | |
| 152 | /* deny if shell does not exists or is not executable */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 153 | if (stat(shell, &st) != 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 154 | logit("User %.100s not allowed because shell %.100s does not exist", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 155 | pw->pw_name, shell); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 156 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 157 | } |
Ben Lindstrom | b61e6df | 2002-03-22 01:15:33 +0000 | [diff] [blame] | 158 | if (S_ISREG(st.st_mode) == 0 || |
| 159 | (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 160 | logit("User %.100s not allowed because shell %.100s is not executable", |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 161 | pw->pw_name, shell); |
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 | |
Darren Tucker | a8f553d | 2005-03-14 23:17:27 +1100 | [diff] [blame] | 165 | if (options.num_deny_users > 0 || options.num_allow_users > 0 || |
| 166 | options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
Damien Miller | 3a961dc | 2003-06-03 10:25:48 +1000 | [diff] [blame] | 167 | hostname = get_canonical_hostname(options.use_dns); |
Ben Lindstrom | 3fb5d00 | 2002-03-05 01:42:42 +0000 | [diff] [blame] | 168 | ipaddr = get_remote_ipaddr(); |
| 169 | } |
| 170 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 171 | /* Return false if user is listed in DenyUsers */ |
| 172 | if (options.num_deny_users > 0) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 173 | for (i = 0; i < options.num_deny_users; i++) |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 174 | if (match_user(pw->pw_name, hostname, ipaddr, |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 175 | options.deny_users[i])) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 176 | logit("User %.100s from %.100s not allowed " |
| 177 | "because listed in DenyUsers", |
| 178 | pw->pw_name, hostname); |
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 | } |
| 182 | /* Return false if AllowUsers isn't empty and user isn't listed there */ |
| 183 | if (options.num_allow_users > 0) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 184 | for (i = 0; i < options.num_allow_users; i++) |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 185 | if (match_user(pw->pw_name, hostname, ipaddr, |
Ben Lindstrom | 6026002 | 2001-07-04 04:56:44 +0000 | [diff] [blame] | 186 | options.allow_users[i])) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 187 | break; |
| 188 | /* i < options.num_allow_users iff we break for loop */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 189 | if (i >= options.num_allow_users) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 190 | logit("User %.100s from %.100s not allowed because " |
| 191 | "not listed in AllowUsers", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 192 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 193 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 194 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 195 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 196 | /* Get the user's group access list (primary and supplementary) */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 197 | if (ga_init(pw->pw_name, pw->pw_gid) == 0) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 198 | logit("User %.100s from %.100s not allowed because " |
| 199 | "not in any group", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 200 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 201 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 202 | |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 203 | /* Return false if one of user's groups is listed in DenyGroups */ |
| 204 | if (options.num_deny_groups > 0) |
| 205 | if (ga_match(options.deny_groups, |
| 206 | options.num_deny_groups)) { |
| 207 | ga_free(); |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 208 | logit("User %.100s from %.100s not allowed " |
| 209 | "because a group is listed in DenyGroups", |
| 210 | pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 211 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 212 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 213 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 214 | * 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] | 215 | * isn't listed there |
| 216 | */ |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 217 | if (options.num_allow_groups > 0) |
| 218 | if (!ga_match(options.allow_groups, |
| 219 | options.num_allow_groups)) { |
| 220 | ga_free(); |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 221 | logit("User %.100s from %.100s not allowed " |
| 222 | "because none of user's groups are listed " |
| 223 | "in AllowGroups", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 224 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 225 | } |
| 226 | ga_free(); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 227 | } |
| 228 | |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 229 | #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER |
Darren Tucker | 691d523 | 2005-02-15 21:45:57 +1100 | [diff] [blame] | 230 | if (!sys_auth_allowed_user(pw, &loginmsg)) |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 231 | return 0; |
| 232 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 233 | |
| 234 | /* We found no reason not to let this user try to log on... */ |
| 235 | return 1; |
| 236 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 237 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 238 | void |
| 239 | auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) |
| 240 | { |
| 241 | void (*authlog) (const char *fmt,...) = verbose; |
| 242 | char *authmsg; |
| 243 | |
Damien Miller | 7a8f5b3 | 2006-03-31 23:14:23 +1100 | [diff] [blame] | 244 | if (use_privsep && !mm_is_monitor() && !authctxt->postponed) |
| 245 | return; |
| 246 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 247 | /* Raise logging level */ |
| 248 | if (authenticated == 1 || |
| 249 | !authctxt->valid || |
Darren Tucker | 89413db | 2004-05-24 10:36:23 +1000 | [diff] [blame] | 250 | authctxt->failures >= options.max_authtries / 2 || |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 251 | strcmp(method, "password") == 0) |
Damien Miller | 2a3f20e | 2003-04-09 21:12:00 +1000 | [diff] [blame] | 252 | authlog = logit; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 253 | |
| 254 | if (authctxt->postponed) |
| 255 | authmsg = "Postponed"; |
| 256 | else |
| 257 | authmsg = authenticated ? "Accepted" : "Failed"; |
| 258 | |
| 259 | authlog("%s %s for %s%.100s from %.200s port %d%s", |
| 260 | authmsg, |
| 261 | method, |
Darren Tucker | 5cb30ad | 2004-08-12 22:40:24 +1000 | [diff] [blame] | 262 | authctxt->valid ? "" : "invalid user ", |
Damien Miller | f655207 | 2001-11-12 11:06:06 +1100 | [diff] [blame] | 263 | authctxt->user, |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 264 | get_remote_ipaddr(), |
| 265 | get_remote_port(), |
| 266 | info); |
Ben Lindstrom | e06eb68 | 2002-07-04 00:27:21 +0000 | [diff] [blame] | 267 | |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 268 | #ifdef CUSTOM_FAILED_LOGIN |
Darren Tucker | 2fba993 | 2005-02-02 23:30:24 +1100 | [diff] [blame] | 269 | if (authenticated == 0 && !authctxt->postponed && |
| 270 | (strcmp(method, "password") == 0 || |
Darren Tucker | 40d9a63 | 2005-02-04 15:19:44 +1100 | [diff] [blame] | 271 | strncmp(method, "keyboard-interactive", 20) == 0 || |
| 272 | strcmp(method, "challenge-response") == 0)) |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 273 | record_failed_login(authctxt->user, |
| 274 | get_canonical_hostname(options.use_dns), "ssh"); |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 275 | #endif |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 276 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | f14b2aa | 2006-05-21 18:26:40 +1000 | [diff] [blame] | 277 | if (authenticated == 0 && !authctxt->postponed) |
| 278 | audit_event(audit_classify_auth(method)); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 279 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 280 | } |
| 281 | |
| 282 | /* |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 283 | * Check whether root logins are disallowed. |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 284 | */ |
| 285 | int |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 286 | auth_root_allowed(char *method) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 287 | { |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 288 | switch (options.permit_root_login) { |
| 289 | case PERMIT_YES: |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 290 | return 1; |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 291 | case PERMIT_NO_PASSWD: |
| 292 | if (strcmp(method, "password") != 0) |
| 293 | return 1; |
| 294 | break; |
| 295 | case PERMIT_FORCED_ONLY: |
| 296 | if (forced_command) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 297 | logit("Root login accepted for forced command."); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 298 | return 1; |
| 299 | } |
| 300 | break; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 301 | } |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 302 | logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 303 | return 0; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 304 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 305 | |
| 306 | |
| 307 | /* |
| 308 | * Given a template and a passwd structure, build a filename |
| 309 | * by substituting % tokenised options. Currently, %% becomes '%', |
| 310 | * %h becomes the home directory and %u the username. |
| 311 | * |
| 312 | * This returns a buffer allocated by xmalloc. |
| 313 | */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 314 | static char * |
| 315 | expand_authorized_keys(const char *filename, struct passwd *pw) |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 316 | { |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 317 | char *file, ret[MAXPATHLEN]; |
| 318 | int i; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 319 | |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 320 | file = percent_expand(filename, "h", pw->pw_dir, |
| 321 | "u", pw->pw_name, (char *)NULL); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 322 | |
| 323 | /* |
| 324 | * Ensure that filename starts anchored. If not, be backward |
| 325 | * compatible and prepend the '%h/' |
| 326 | */ |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 327 | if (*file == '/') |
| 328 | return (file); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 329 | |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 330 | i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); |
| 331 | if (i < 0 || (size_t)i >= sizeof(ret)) |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 332 | fatal("expand_authorized_keys: path too long"); |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 333 | xfree(file); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 334 | return (xstrdup(ret)); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 335 | } |
| 336 | |
| 337 | char * |
| 338 | authorized_keys_file(struct passwd *pw) |
| 339 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 340 | return expand_authorized_keys(options.authorized_keys_file, pw); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 341 | } |
| 342 | |
| 343 | char * |
| 344 | authorized_keys_file2(struct passwd *pw) |
| 345 | { |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 346 | return expand_authorized_keys(options.authorized_keys_file2, pw); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 347 | } |
| 348 | |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 349 | /* return ok if key exists in sysfile or userfile */ |
| 350 | HostStatus |
| 351 | check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, |
| 352 | const char *sysfile, const char *userfile) |
| 353 | { |
| 354 | Key *found; |
| 355 | char *user_hostfile; |
| 356 | struct stat st; |
Ben Lindstrom | 65366a8 | 2001-12-06 16:32:47 +0000 | [diff] [blame] | 357 | HostStatus host_status; |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 358 | |
| 359 | /* Check if we know the host and its host key. */ |
| 360 | found = key_new(key->type); |
| 361 | host_status = check_host_in_hostfile(sysfile, host, key, found, NULL); |
| 362 | |
| 363 | if (host_status != HOST_OK && userfile != NULL) { |
| 364 | user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); |
| 365 | if (options.strict_modes && |
| 366 | (stat(user_hostfile, &st) == 0) && |
| 367 | ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 368 | (st.st_mode & 022) != 0)) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 369 | logit("Authentication refused for %.100s: " |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 370 | "bad owner or modes for %.200s", |
| 371 | pw->pw_name, user_hostfile); |
| 372 | } else { |
| 373 | temporarily_use_uid(pw); |
| 374 | host_status = check_host_in_hostfile(user_hostfile, |
| 375 | host, key, found, NULL); |
| 376 | restore_uid(); |
| 377 | } |
| 378 | xfree(user_hostfile); |
| 379 | } |
| 380 | key_free(found); |
| 381 | |
| 382 | debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ? |
| 383 | "ok" : "not found", host); |
| 384 | return host_status; |
| 385 | } |
| 386 | |
| 387 | |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 388 | /* |
| 389 | * Check a given file for security. This is defined as all components |
Ben Lindstrom | d4ee349 | 2002-08-20 18:42:13 +0000 | [diff] [blame] | 390 | * 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] | 391 | * 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] | 392 | * |
| 393 | * XXX Should any specific check be done for sym links ? |
| 394 | * |
| 395 | * Takes an open file descriptor, the file name, a uid and and |
| 396 | * error buffer plus max size as arguments. |
| 397 | * |
| 398 | * Returns 0 on success and -1 on failure |
| 399 | */ |
| 400 | int |
Ben Lindstrom | 248c078 | 2001-07-04 03:40:39 +0000 | [diff] [blame] | 401 | secure_filename(FILE *f, const char *file, struct passwd *pw, |
| 402 | char *err, size_t errlen) |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 403 | { |
Ben Lindstrom | 248c078 | 2001-07-04 03:40:39 +0000 | [diff] [blame] | 404 | uid_t uid = pw->pw_uid; |
Ben Lindstrom | c3e49e7 | 2001-10-03 17:55:26 +0000 | [diff] [blame] | 405 | char buf[MAXPATHLEN], homedir[MAXPATHLEN]; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 406 | char *cp; |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 407 | int comparehome = 0; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 408 | struct stat st; |
| 409 | |
| 410 | if (realpath(file, buf) == NULL) { |
| 411 | snprintf(err, errlen, "realpath %s failed: %s", file, |
| 412 | strerror(errno)); |
| 413 | return -1; |
| 414 | } |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 415 | if (realpath(pw->pw_dir, homedir) != NULL) |
| 416 | comparehome = 1; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 417 | |
| 418 | /* check the open file to avoid races */ |
| 419 | if (fstat(fileno(f), &st) < 0 || |
| 420 | (st.st_uid != 0 && st.st_uid != uid) || |
| 421 | (st.st_mode & 022) != 0) { |
| 422 | snprintf(err, errlen, "bad ownership or modes for file %s", |
| 423 | buf); |
| 424 | return -1; |
| 425 | } |
| 426 | |
| 427 | /* for each component of the canonical path, walking upwards */ |
| 428 | for (;;) { |
| 429 | if ((cp = dirname(buf)) == NULL) { |
| 430 | snprintf(err, errlen, "dirname() failed"); |
| 431 | return -1; |
| 432 | } |
| 433 | strlcpy(buf, cp, sizeof(buf)); |
| 434 | |
| 435 | debug3("secure_filename: checking '%s'", buf); |
| 436 | if (stat(buf, &st) < 0 || |
| 437 | (st.st_uid != 0 && st.st_uid != uid) || |
| 438 | (st.st_mode & 022) != 0) { |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 439 | snprintf(err, errlen, |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 440 | "bad ownership or modes for directory %s", buf); |
| 441 | return -1; |
| 442 | } |
| 443 | |
Damien Miller | 0ae6e00 | 2001-07-14 12:21:34 +1000 | [diff] [blame] | 444 | /* If are passed the homedir then we can stop */ |
Ben Lindstrom | 485075e | 2002-11-09 15:45:12 +0000 | [diff] [blame] | 445 | if (comparehome && strcmp(homedir, buf) == 0) { |
Damien Miller | 0ae6e00 | 2001-07-14 12:21:34 +1000 | [diff] [blame] | 446 | debug3("secure_filename: terminating check at '%s'", |
| 447 | buf); |
| 448 | break; |
| 449 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 450 | /* |
| 451 | * dirname should always complete with a "/" path, |
| 452 | * but we can be paranoid and check for "." too |
| 453 | */ |
| 454 | if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) |
| 455 | break; |
| 456 | } |
| 457 | return 0; |
| 458 | } |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 459 | |
| 460 | struct passwd * |
| 461 | getpwnamallow(const char *user) |
| 462 | { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 463 | #ifdef HAVE_LOGIN_CAP |
| 464 | extern login_cap_t *lc; |
| 465 | #ifdef BSD_AUTH |
| 466 | auth_session_t *as; |
| 467 | #endif |
| 468 | #endif |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 469 | struct passwd *pw; |
| 470 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 471 | parse_server_match_config(&options, user, |
| 472 | get_canonical_hostname(options.use_dns), get_remote_ipaddr()); |
| 473 | |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 474 | pw = getpwnam(user); |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 475 | if (pw == NULL) { |
Damien Miller | a22f2d7 | 2004-07-21 20:48:24 +1000 | [diff] [blame] | 476 | logit("Invalid user %.100s from %.100s", |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 477 | user, get_remote_ipaddr()); |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 478 | #ifdef CUSTOM_FAILED_LOGIN |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 479 | record_failed_login(user, |
| 480 | get_canonical_hostname(options.use_dns), "ssh"); |
Ben Lindstrom | f5397c0 | 2002-11-09 16:11:10 +0000 | [diff] [blame] | 481 | #endif |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 482 | #ifdef SSH_AUDIT_EVENTS |
| 483 | audit_event(SSH_INVALID_USER); |
| 484 | #endif /* SSH_AUDIT_EVENTS */ |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 485 | return (NULL); |
| 486 | } |
| 487 | if (!allowed_user(pw)) |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 488 | return (NULL); |
| 489 | #ifdef HAVE_LOGIN_CAP |
| 490 | if ((lc = login_getclass(pw->pw_class)) == NULL) { |
| 491 | debug("unable to get login class: %s", user); |
| 492 | return (NULL); |
| 493 | } |
| 494 | #ifdef BSD_AUTH |
| 495 | if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || |
Damien Miller | 13e35a0 | 2002-05-22 14:04:11 +1000 | [diff] [blame] | 496 | auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 497 | debug("Approval failure for %s", user); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 498 | pw = NULL; |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 499 | } |
| 500 | if (as != NULL) |
| 501 | auth_close(as); |
| 502 | #endif |
| 503 | #endif |
Ben Lindstrom | f34e4eb | 2002-03-22 03:08:30 +0000 | [diff] [blame] | 504 | if (pw != NULL) |
| 505 | return (pwcopy(pw)); |
| 506 | return (NULL); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 507 | } |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 508 | |
| 509 | void |
| 510 | auth_debug_add(const char *fmt,...) |
| 511 | { |
| 512 | char buf[1024]; |
| 513 | va_list args; |
| 514 | |
| 515 | if (!auth_debug_init) |
| 516 | return; |
| 517 | |
| 518 | va_start(args, fmt); |
| 519 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 520 | va_end(args); |
| 521 | buffer_put_cstring(&auth_debug, buf); |
| 522 | } |
| 523 | |
| 524 | void |
| 525 | auth_debug_send(void) |
| 526 | { |
| 527 | char *msg; |
| 528 | |
| 529 | if (!auth_debug_init) |
| 530 | return; |
| 531 | while (buffer_len(&auth_debug)) { |
| 532 | msg = buffer_get_string(&auth_debug, NULL); |
| 533 | packet_send_debug("%s", msg); |
| 534 | xfree(msg); |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | void |
| 539 | auth_debug_reset(void) |
| 540 | { |
| 541 | if (auth_debug_init) |
| 542 | buffer_clear(&auth_debug); |
| 543 | else { |
| 544 | buffer_init(&auth_debug); |
| 545 | auth_debug_init = 1; |
| 546 | } |
| 547 | } |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 548 | |
| 549 | struct passwd * |
| 550 | fakepw(void) |
| 551 | { |
| 552 | static struct passwd fake; |
| 553 | |
| 554 | memset(&fake, 0, sizeof(fake)); |
| 555 | fake.pw_name = "NOUSER"; |
| 556 | fake.pw_passwd = |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 557 | "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 558 | fake.pw_gecos = "NOUSER"; |
Darren Tucker | 1f8311c | 2004-05-13 16:39:33 +1000 | [diff] [blame] | 559 | fake.pw_uid = (uid_t)-1; |
| 560 | fake.pw_gid = (gid_t)-1; |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 561 | #ifdef HAVE_PW_CLASS_IN_PASSWD |
| 562 | fake.pw_class = ""; |
| 563 | #endif |
| 564 | fake.pw_dir = "/nonexist"; |
| 565 | fake.pw_shell = "/nonexist"; |
| 566 | |
| 567 | return (&fake); |
| 568 | } |