djm@openbsd.org | 0fa174e | 2019-01-19 21:31:32 +0000 | [diff] [blame] | 1 | /* $OpenBSD: auth.c,v 1.136 2019/01/19 21:31:32 djm 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> |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 30 | #include <sys/socket.h> |
markus@openbsd.org | 25cf910 | 2018-01-08 15:21:49 +0000 | [diff] [blame] | 31 | #include <sys/wait.h> |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 32 | |
Damien Miller | 36cbe41 | 2006-08-05 12:54:24 +1000 | [diff] [blame] | 33 | #include <netinet/in.h> |
| 34 | |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 35 | #include <errno.h> |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 36 | #include <fcntl.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 37 | #ifdef HAVE_PATHS_H |
Damien Miller | a9263d0 | 2006-03-15 11:18:26 +1100 | [diff] [blame] | 38 | # include <paths.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 39 | #endif |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 40 | #include <pwd.h> |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 41 | #ifdef HAVE_LOGIN_H |
| 42 | #include <login.h> |
| 43 | #endif |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 44 | #ifdef USE_SHADOW |
Damien Miller | 1f335fb | 2000-06-26 11:31:33 +1000 | [diff] [blame] | 45 | #include <shadow.h> |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 46 | #endif |
Darren Tucker | 5d19626 | 2006-07-12 22:15:16 +1000 | [diff] [blame] | 47 | #include <stdarg.h> |
Damien Miller | a7a73ee | 2006-08-05 11:37:59 +1000 | [diff] [blame] | 48 | #include <stdio.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 49 | #include <string.h> |
Damien Miller | 7acf550 | 2008-07-09 20:54:37 +1000 | [diff] [blame] | 50 | #include <unistd.h> |
deraadt@openbsd.org | 087266e | 2015-01-20 23:14:00 +0000 | [diff] [blame] | 51 | #include <limits.h> |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 52 | #include <netdb.h> |
djm@openbsd.org | 943d096 | 2019-01-17 04:20:53 +0000 | [diff] [blame] | 53 | #include <time.h> |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 54 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 55 | #include "xmalloc.h" |
| 56 | #include "match.h" |
| 57 | #include "groupaccess.h" |
| 58 | #include "log.h" |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 59 | #include "sshbuf.h" |
Damien Miller | 7acefbb | 2014-07-18 14:11:24 +1000 | [diff] [blame] | 60 | #include "misc.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 61 | #include "servconf.h" |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 62 | #include "sshkey.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 63 | #include "hostfile.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 64 | #include "auth.h" |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 65 | #include "auth-options.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 66 | #include "canohost.h" |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 67 | #include "uidswap.h" |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 68 | #include "packet.h" |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 69 | #include "loginrec.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 70 | #ifdef GSSAPI |
| 71 | #include "ssh-gss.h" |
| 72 | #endif |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 73 | #include "authfile.h" |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 74 | #include "monitor_wrap.h" |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 75 | #include "authfile.h" |
| 76 | #include "ssherr.h" |
Darren Tucker | 0acca37 | 2013-06-02 07:41:51 +1000 | [diff] [blame] | 77 | #include "compat.h" |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 78 | #include "channels.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 79 | |
djm@openbsd.org | 0fa174e | 2019-01-19 21:31:32 +0000 | [diff] [blame] | 80 | #include "opacket.h" /* XXX */ |
| 81 | extern struct ssh *active_state; /* XXX */ |
| 82 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 83 | /* import */ |
| 84 | extern ServerOptions options; |
Damien Miller | 7a8f5b3 | 2006-03-31 23:14:23 +1100 | [diff] [blame] | 85 | extern int use_privsep; |
Damien Miller | 120a1ec | 2018-07-10 19:39:52 +1000 | [diff] [blame] | 86 | extern struct sshbuf *loginmsg; |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 87 | extern struct passwd *privsep_pw; |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 88 | extern struct sshauthopt *auth_opts; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 89 | |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 90 | /* Debugging messages */ |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 91 | static struct sshbuf *auth_debug; |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 92 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 93 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 94 | * Check if the user is allowed to log in via ssh. If user is listed |
| 95 | * in DenyUsers or one of user's groups is listed in DenyGroups, false |
| 96 | * will be returned. If AllowUsers isn't empty and user isn't listed |
| 97 | * there, or if AllowGroups isn't empty and one of user's groups isn't |
| 98 | * listed there, false will be returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 99 | * If the user's shell is not executable, false will be returned. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 100 | * Otherwise true is returned. |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 101 | */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 102 | int |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 103 | allowed_user(struct passwd * pw) |
| 104 | { |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 105 | struct ssh *ssh = active_state; /* XXX */ |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 106 | struct stat st; |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 107 | const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 108 | u_int i; |
djm@openbsd.org | 010359b | 2016-11-06 05:46:37 +0000 | [diff] [blame] | 109 | int r; |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 110 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 111 | struct spwd *spw = NULL; |
Tim Rice | 458c6bf | 2003-01-08 20:04:27 -0800 | [diff] [blame] | 112 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 113 | |
| 114 | /* 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] | 115 | if (!pw || !pw->pw_name) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 116 | return 0; |
| 117 | |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 118 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 119 | if (!options.use_pam) |
| 120 | spw = getspnam(pw->pw_name); |
| 121 | #ifdef HAS_SHADOW_EXPIRE |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 122 | if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) |
| 123 | return 0; |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 124 | #endif /* HAS_SHADOW_EXPIRE */ |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 125 | #endif /* USE_SHADOW */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 126 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 127 | /* grab passwd field for locked account check */ |
Damien Miller | 22989f1 | 2008-07-05 08:59:43 +1000 | [diff] [blame] | 128 | passwd = pw->pw_passwd; |
Darren Tucker | 15ee748 | 2004-02-22 09:43:15 +1100 | [diff] [blame] | 129 | #ifdef USE_SHADOW |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 130 | if (spw != NULL) |
Tim Rice | 99203ec | 2007-03-26 09:35:28 -0700 | [diff] [blame] | 131 | #ifdef USE_LIBIAF |
Tim Rice | 2291c00 | 2005-08-26 13:15:19 -0700 | [diff] [blame] | 132 | passwd = get_iaf_password(pw); |
| 133 | #else |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 134 | passwd = spw->sp_pwdp; |
Tim Rice | 99203ec | 2007-03-26 09:35:28 -0700 | [diff] [blame] | 135 | #endif /* USE_LIBIAF */ |
Damien Miller | 06817f9 | 2003-01-07 23:55:59 +1100 | [diff] [blame] | 136 | #endif |
| 137 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 138 | /* check for locked account */ |
Darren Tucker | 43a0dc6 | 2003-08-26 14:22:12 +1000 | [diff] [blame] | 139 | if (!options.use_pam && passwd && *passwd) { |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 140 | int locked = 0; |
| 141 | |
| 142 | #ifdef LOCKED_PASSWD_STRING |
| 143 | if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) |
| 144 | locked = 1; |
| 145 | #endif |
| 146 | #ifdef LOCKED_PASSWD_PREFIX |
| 147 | if (strncmp(passwd, LOCKED_PASSWD_PREFIX, |
| 148 | strlen(LOCKED_PASSWD_PREFIX)) == 0) |
| 149 | locked = 1; |
| 150 | #endif |
| 151 | #ifdef LOCKED_PASSWD_SUBSTR |
| 152 | if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) |
| 153 | locked = 1; |
| 154 | #endif |
Tim Rice | 99203ec | 2007-03-26 09:35:28 -0700 | [diff] [blame] | 155 | #ifdef USE_LIBIAF |
Tim Rice | ad7d547 | 2010-08-12 10:33:01 -0700 | [diff] [blame] | 156 | free((void *) passwd); |
Tim Rice | 99203ec | 2007-03-26 09:35:28 -0700 | [diff] [blame] | 157 | #endif /* USE_LIBIAF */ |
Darren Tucker | e41bba5 | 2003-08-25 11:51:19 +1000 | [diff] [blame] | 158 | if (locked) { |
| 159 | logit("User %.100s not allowed because account is locked", |
| 160 | pw->pw_name); |
| 161 | return 0; |
| 162 | } |
| 163 | } |
| 164 | |
Damien Miller | ef7df54 | 2000-05-19 00:03:23 +1000 | [diff] [blame] | 165 | /* |
Damien Miller | 47cf16b | 2010-02-12 09:25:29 +1100 | [diff] [blame] | 166 | * Deny if shell does not exist or is not executable unless we |
| 167 | * are chrooting. |
Damien Miller | ef7df54 | 2000-05-19 00:03:23 +1000 | [diff] [blame] | 168 | */ |
Damien Miller | 47cf16b | 2010-02-12 09:25:29 +1100 | [diff] [blame] | 169 | if (options.chroot_directory == NULL || |
| 170 | strcasecmp(options.chroot_directory, "none") == 0) { |
| 171 | char *shell = xstrdup((pw->pw_shell[0] == '\0') ? |
| 172 | _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */ |
Darren Tucker | 94881d8 | 2010-01-15 11:44:46 +1100 | [diff] [blame] | 173 | |
Damien Miller | 47cf16b | 2010-02-12 09:25:29 +1100 | [diff] [blame] | 174 | if (stat(shell, &st) != 0) { |
| 175 | logit("User %.100s not allowed because shell %.100s " |
| 176 | "does not exist", pw->pw_name, shell); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 177 | free(shell); |
Damien Miller | 47cf16b | 2010-02-12 09:25:29 +1100 | [diff] [blame] | 178 | return 0; |
| 179 | } |
| 180 | if (S_ISREG(st.st_mode) == 0 || |
| 181 | (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { |
| 182 | logit("User %.100s not allowed because shell %.100s " |
| 183 | "is not executable", pw->pw_name, shell); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 184 | free(shell); |
Damien Miller | 47cf16b | 2010-02-12 09:25:29 +1100 | [diff] [blame] | 185 | return 0; |
| 186 | } |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 187 | free(shell); |
Darren Tucker | 94881d8 | 2010-01-15 11:44:46 +1100 | [diff] [blame] | 188 | } |
Damien Miller | ef7df54 | 2000-05-19 00:03:23 +1000 | [diff] [blame] | 189 | |
Darren Tucker | a8f553d | 2005-03-14 23:17:27 +1100 | [diff] [blame] | 190 | if (options.num_deny_users > 0 || options.num_allow_users > 0 || |
| 191 | options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 192 | hostname = auth_get_canonical_hostname(ssh, options.use_dns); |
| 193 | ipaddr = ssh_remote_ipaddr(ssh); |
Ben Lindstrom | 3fb5d00 | 2002-03-05 01:42:42 +0000 | [diff] [blame] | 194 | } |
| 195 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 196 | /* Return false if user is listed in DenyUsers */ |
| 197 | if (options.num_deny_users > 0) { |
dtucker@openbsd.org | fe06b68 | 2016-12-15 21:29:05 +0000 | [diff] [blame] | 198 | for (i = 0; i < options.num_deny_users; i++) { |
djm@openbsd.org | 010359b | 2016-11-06 05:46:37 +0000 | [diff] [blame] | 199 | r = match_user(pw->pw_name, hostname, ipaddr, |
| 200 | options.deny_users[i]); |
| 201 | if (r < 0) { |
| 202 | fatal("Invalid DenyUsers pattern \"%.100s\"", |
| 203 | options.deny_users[i]); |
djm@openbsd.org | 1a6f9d2 | 2016-11-08 22:04:34 +0000 | [diff] [blame] | 204 | } else if (r != 0) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 205 | logit("User %.100s from %.100s not allowed " |
| 206 | "because listed in DenyUsers", |
| 207 | pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 208 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 209 | } |
dtucker@openbsd.org | fe06b68 | 2016-12-15 21:29:05 +0000 | [diff] [blame] | 210 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 211 | } |
| 212 | /* Return false if AllowUsers isn't empty and user isn't listed there */ |
| 213 | if (options.num_allow_users > 0) { |
djm@openbsd.org | 010359b | 2016-11-06 05:46:37 +0000 | [diff] [blame] | 214 | for (i = 0; i < options.num_allow_users; i++) { |
| 215 | r = match_user(pw->pw_name, hostname, ipaddr, |
| 216 | options.allow_users[i]); |
| 217 | if (r < 0) { |
| 218 | fatal("Invalid AllowUsers pattern \"%.100s\"", |
| 219 | options.allow_users[i]); |
| 220 | } else if (r == 1) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 221 | break; |
djm@openbsd.org | 010359b | 2016-11-06 05:46:37 +0000 | [diff] [blame] | 222 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 223 | /* i < options.num_allow_users iff we break for loop */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 224 | if (i >= options.num_allow_users) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 225 | logit("User %.100s from %.100s not allowed because " |
| 226 | "not listed in AllowUsers", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 227 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 228 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 229 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 230 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 231 | /* Get the user's group access list (primary and supplementary) */ |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 232 | if (ga_init(pw->pw_name, pw->pw_gid) == 0) { |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 233 | logit("User %.100s from %.100s not allowed because " |
| 234 | "not in any group", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 235 | return 0; |
Ben Lindstrom | 6ef9ec6 | 2002-03-05 01:40:37 +0000 | [diff] [blame] | 236 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 237 | |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 238 | /* Return false if one of user's groups is listed in DenyGroups */ |
| 239 | if (options.num_deny_groups > 0) |
| 240 | if (ga_match(options.deny_groups, |
| 241 | options.num_deny_groups)) { |
| 242 | ga_free(); |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 243 | logit("User %.100s from %.100s not allowed " |
| 244 | "because a group is listed in DenyGroups", |
| 245 | pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 246 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 247 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 248 | /* |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 249 | * 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] | 250 | * isn't listed there |
| 251 | */ |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 252 | if (options.num_allow_groups > 0) |
| 253 | if (!ga_match(options.allow_groups, |
| 254 | options.num_allow_groups)) { |
| 255 | ga_free(); |
Darren Tucker | 094cd0b | 2005-01-24 21:56:48 +1100 | [diff] [blame] | 256 | logit("User %.100s from %.100s not allowed " |
| 257 | "because none of user's groups are listed " |
| 258 | "in AllowGroups", pw->pw_name, hostname); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 259 | return 0; |
Kevin Steves | 7b61cfa | 2001-01-14 19:11:00 +0000 | [diff] [blame] | 260 | } |
| 261 | ga_free(); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 262 | } |
| 263 | |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 264 | #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER |
Kevin Adler | a784fa8 | 2018-12-12 22:12:45 -0600 | [diff] [blame] | 265 | if (!sys_auth_allowed_user(pw, loginmsg)) |
Darren Tucker | 0a9d43d | 2004-06-23 13:45:24 +1000 | [diff] [blame] | 266 | return 0; |
| 267 | #endif |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 268 | |
| 269 | /* We found no reason not to let this user try to log on... */ |
| 270 | return 1; |
| 271 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 272 | |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 273 | /* |
| 274 | * Formats any key left in authctxt->auth_method_key for inclusion in |
| 275 | * auth_log()'s message. Also includes authxtct->auth_method_info if present. |
| 276 | */ |
| 277 | static char * |
| 278 | format_method_key(Authctxt *authctxt) |
Darren Tucker | 0acca37 | 2013-06-02 07:41:51 +1000 | [diff] [blame] | 279 | { |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 280 | const struct sshkey *key = authctxt->auth_method_key; |
| 281 | const char *methinfo = authctxt->auth_method_info; |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 282 | char *fp, *cafp, *ret = NULL; |
Darren Tucker | 0acca37 | 2013-06-02 07:41:51 +1000 | [diff] [blame] | 283 | |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 284 | if (key == NULL) |
| 285 | return NULL; |
Darren Tucker | 0acca37 | 2013-06-02 07:41:51 +1000 | [diff] [blame] | 286 | |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 287 | if (sshkey_is_cert(key)) { |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 288 | fp = sshkey_fingerprint(key, |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 289 | options.fingerprint_hash, SSH_FP_DEFAULT); |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 290 | cafp = sshkey_fingerprint(key->cert->signature_key, |
| 291 | options.fingerprint_hash, SSH_FP_DEFAULT); |
| 292 | xasprintf(&ret, "%s %s ID %s (serial %llu) CA %s %s%s%s", |
| 293 | sshkey_type(key), fp == NULL ? "(null)" : fp, |
| 294 | key->cert->key_id, |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 295 | (unsigned long long)key->cert->serial, |
| 296 | sshkey_type(key->cert->signature_key), |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 297 | cafp == NULL ? "(null)" : cafp, |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 298 | methinfo == NULL ? "" : ", ", |
| 299 | methinfo == NULL ? "" : methinfo); |
| 300 | free(fp); |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 301 | free(cafp); |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 302 | } else { |
| 303 | fp = sshkey_fingerprint(key, options.fingerprint_hash, |
| 304 | SSH_FP_DEFAULT); |
| 305 | xasprintf(&ret, "%s %s%s%s", sshkey_type(key), |
| 306 | fp == NULL ? "(null)" : fp, |
| 307 | methinfo == NULL ? "" : ", ", |
| 308 | methinfo == NULL ? "" : methinfo); |
| 309 | free(fp); |
| 310 | } |
| 311 | return ret; |
Darren Tucker | 0acca37 | 2013-06-02 07:41:51 +1000 | [diff] [blame] | 312 | } |
| 313 | |
| 314 | void |
Damien Miller | 15b05cf | 2012-12-03 09:53:20 +1100 | [diff] [blame] | 315 | auth_log(Authctxt *authctxt, int authenticated, int partial, |
Darren Tucker | 0acca37 | 2013-06-02 07:41:51 +1000 | [diff] [blame] | 316 | const char *method, const char *submethod) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 317 | { |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 318 | struct ssh *ssh = active_state; /* XXX */ |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 319 | int level = SYSLOG_LEVEL_VERBOSE; |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 320 | const char *authmsg; |
| 321 | char *extra = NULL; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 322 | |
Damien Miller | 7a8f5b3 | 2006-03-31 23:14:23 +1100 | [diff] [blame] | 323 | if (use_privsep && !mm_is_monitor() && !authctxt->postponed) |
| 324 | return; |
| 325 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 326 | /* Raise logging level */ |
| 327 | if (authenticated == 1 || |
| 328 | !authctxt->valid || |
Darren Tucker | 89413db | 2004-05-24 10:36:23 +1000 | [diff] [blame] | 329 | authctxt->failures >= options.max_authtries / 2 || |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 330 | strcmp(method, "password") == 0) |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 331 | level = SYSLOG_LEVEL_INFO; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 332 | |
| 333 | if (authctxt->postponed) |
| 334 | authmsg = "Postponed"; |
Damien Miller | 15b05cf | 2012-12-03 09:53:20 +1100 | [diff] [blame] | 335 | else if (partial) |
| 336 | authmsg = "Partial"; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 337 | else |
| 338 | authmsg = authenticated ? "Accepted" : "Failed"; |
| 339 | |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 340 | if ((extra = format_method_key(authctxt)) == NULL) { |
| 341 | if (authctxt->auth_method_info != NULL) |
| 342 | extra = xstrdup(authctxt->auth_method_info); |
| 343 | } |
| 344 | |
djm@openbsd.org | 50e2687 | 2018-09-12 01:19:12 +0000 | [diff] [blame] | 345 | do_log2(level, "%s %s%s%s for %s%.100s from %.200s port %d ssh2%s%s", |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 346 | authmsg, |
| 347 | method, |
Damien Miller | 15b05cf | 2012-12-03 09:53:20 +1100 | [diff] [blame] | 348 | submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod, |
Darren Tucker | 5cb30ad | 2004-08-12 22:40:24 +1000 | [diff] [blame] | 349 | authctxt->valid ? "" : "invalid user ", |
Damien Miller | f655207 | 2001-11-12 11:06:06 +1100 | [diff] [blame] | 350 | authctxt->user, |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 351 | ssh_remote_ipaddr(ssh), |
| 352 | ssh_remote_port(ssh), |
djm@openbsd.org | 8f57495 | 2017-06-24 06:34:38 +0000 | [diff] [blame] | 353 | extra != NULL ? ": " : "", |
| 354 | extra != NULL ? extra : ""); |
| 355 | |
| 356 | free(extra); |
Ben Lindstrom | e06eb68 | 2002-07-04 00:27:21 +0000 | [diff] [blame] | 357 | |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 358 | #ifdef CUSTOM_FAILED_LOGIN |
Darren Tucker | 2fba993 | 2005-02-02 23:30:24 +1100 | [diff] [blame] | 359 | if (authenticated == 0 && !authctxt->postponed && |
| 360 | (strcmp(method, "password") == 0 || |
Darren Tucker | 40d9a63 | 2005-02-04 15:19:44 +1100 | [diff] [blame] | 361 | strncmp(method, "keyboard-interactive", 20) == 0 || |
| 362 | strcmp(method, "challenge-response") == 0)) |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 363 | record_failed_login(authctxt->user, |
Darren Tucker | 885fb2a | 2016-03-08 11:58:43 +1100 | [diff] [blame] | 364 | auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); |
Darren Tucker | 26d4e19 | 2006-08-30 22:33:09 +1000 | [diff] [blame] | 365 | # ifdef WITH_AIXAUTHENTICATE |
| 366 | if (authenticated) |
| 367 | sys_auth_record_login(authctxt->user, |
Darren Tucker | 885fb2a | 2016-03-08 11:58:43 +1100 | [diff] [blame] | 368 | auth_get_canonical_hostname(ssh, options.use_dns), "ssh", |
Kevin Adler | a784fa8 | 2018-12-12 22:12:45 -0600 | [diff] [blame] | 369 | loginmsg); |
Darren Tucker | 26d4e19 | 2006-08-30 22:33:09 +1000 | [diff] [blame] | 370 | # endif |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 371 | #endif |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 372 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | f14b2aa | 2006-05-21 18:26:40 +1000 | [diff] [blame] | 373 | if (authenticated == 0 && !authctxt->postponed) |
| 374 | audit_event(audit_classify_auth(method)); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 375 | #endif |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 376 | } |
| 377 | |
Damien Miller | 686feb5 | 2014-07-03 21:29:38 +1000 | [diff] [blame] | 378 | |
| 379 | void |
| 380 | auth_maxtries_exceeded(Authctxt *authctxt) |
| 381 | { |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 382 | struct ssh *ssh = active_state; /* XXX */ |
| 383 | |
djm@openbsd.org | 6f62160 | 2015-02-25 17:29:38 +0000 | [diff] [blame] | 384 | error("maximum authentication attempts exceeded for " |
markus@openbsd.org | 6cb6dcf | 2016-08-13 17:47:40 +0000 | [diff] [blame] | 385 | "%s%.100s from %.200s port %d ssh2", |
Damien Miller | 686feb5 | 2014-07-03 21:29:38 +1000 | [diff] [blame] | 386 | authctxt->valid ? "" : "invalid user ", |
| 387 | authctxt->user, |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 388 | ssh_remote_ipaddr(ssh), |
markus@openbsd.org | 6cb6dcf | 2016-08-13 17:47:40 +0000 | [diff] [blame] | 389 | ssh_remote_port(ssh)); |
djm@openbsd.org | 6f62160 | 2015-02-25 17:29:38 +0000 | [diff] [blame] | 390 | packet_disconnect("Too many authentication failures"); |
Damien Miller | 686feb5 | 2014-07-03 21:29:38 +1000 | [diff] [blame] | 391 | /* NOTREACHED */ |
| 392 | } |
| 393 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 394 | /* |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 395 | * Check whether root logins are disallowed. |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 396 | */ |
| 397 | int |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 398 | auth_root_allowed(struct ssh *ssh, const char *method) |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 399 | { |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 400 | switch (options.permit_root_login) { |
| 401 | case PERMIT_YES: |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 402 | return 1; |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 403 | case PERMIT_NO_PASSWD: |
deraadt@openbsd.org | 1dc8d93 | 2015-08-06 14:53:21 +0000 | [diff] [blame] | 404 | if (strcmp(method, "publickey") == 0 || |
| 405 | strcmp(method, "hostbased") == 0 || |
djm@openbsd.org | 32a1819 | 2015-08-21 03:42:19 +0000 | [diff] [blame] | 406 | strcmp(method, "gssapi-with-mic") == 0) |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 407 | return 1; |
| 408 | break; |
| 409 | case PERMIT_FORCED_ONLY: |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 410 | if (auth_opts->force_command != NULL) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 411 | logit("Root login accepted for forced command."); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 412 | return 1; |
| 413 | } |
| 414 | break; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 415 | } |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 416 | logit("ROOT LOGIN REFUSED FROM %.200s port %d", |
| 417 | ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
Ben Lindstrom | d8a9021 | 2001-02-15 03:08:27 +0000 | [diff] [blame] | 418 | return 0; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 419 | } |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 420 | |
| 421 | |
| 422 | /* |
| 423 | * Given a template and a passwd structure, build a filename |
| 424 | * by substituting % tokenised options. Currently, %% becomes '%', |
| 425 | * %h becomes the home directory and %u the username. |
| 426 | * |
| 427 | * This returns a buffer allocated by xmalloc. |
| 428 | */ |
Damien Miller | d8478b6 | 2011-05-29 21:39:36 +1000 | [diff] [blame] | 429 | char * |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 430 | expand_authorized_keys(const char *filename, struct passwd *pw) |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 431 | { |
djm@openbsd.org | 9c935dd | 2018-06-01 03:33:53 +0000 | [diff] [blame] | 432 | char *file, uidstr[32], ret[PATH_MAX]; |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 433 | int i; |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 434 | |
djm@openbsd.org | 9c935dd | 2018-06-01 03:33:53 +0000 | [diff] [blame] | 435 | snprintf(uidstr, sizeof(uidstr), "%llu", |
| 436 | (unsigned long long)pw->pw_uid); |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 437 | file = percent_expand(filename, "h", pw->pw_dir, |
djm@openbsd.org | 9c935dd | 2018-06-01 03:33:53 +0000 | [diff] [blame] | 438 | "u", pw->pw_name, "U", uidstr, (char *)NULL); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 439 | |
| 440 | /* |
| 441 | * Ensure that filename starts anchored. If not, be backward |
| 442 | * compatible and prepend the '%h/' |
| 443 | */ |
djm@openbsd.org | 2a35862 | 2018-11-16 03:26:01 +0000 | [diff] [blame] | 444 | if (path_absolute(file)) |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 445 | return (file); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 446 | |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 447 | i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); |
| 448 | if (i < 0 || (size_t)i >= sizeof(ret)) |
Damien Miller | 6476cad | 2005-06-16 13:18:34 +1000 | [diff] [blame] | 449 | fatal("expand_authorized_keys: path too long"); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 450 | free(file); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 451 | return (xstrdup(ret)); |
Ben Lindstrom | bfb3a0e | 2001-06-05 20:25:05 +0000 | [diff] [blame] | 452 | } |
| 453 | |
| 454 | char * |
Damien Miller | 30da344 | 2010-05-10 11:58:03 +1000 | [diff] [blame] | 455 | authorized_principals_file(struct passwd *pw) |
| 456 | { |
djm@openbsd.org | 7e8528c | 2015-05-01 04:17:51 +0000 | [diff] [blame] | 457 | if (options.authorized_principals_file == NULL) |
Damien Miller | 30da344 | 2010-05-10 11:58:03 +1000 | [diff] [blame] | 458 | return NULL; |
| 459 | return expand_authorized_keys(options.authorized_principals_file, pw); |
| 460 | } |
| 461 | |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 462 | /* return ok if key exists in sysfile or userfile */ |
| 463 | HostStatus |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 464 | check_key_in_hostfiles(struct passwd *pw, struct sshkey *key, const char *host, |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 465 | const char *sysfile, const char *userfile) |
| 466 | { |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 467 | char *user_hostfile; |
| 468 | struct stat st; |
Ben Lindstrom | 65366a8 | 2001-12-06 16:32:47 +0000 | [diff] [blame] | 469 | HostStatus host_status; |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 470 | struct hostkeys *hostkeys; |
| 471 | const struct hostkey_entry *found; |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 472 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 473 | hostkeys = init_hostkeys(); |
| 474 | load_hostkeys(hostkeys, host, sysfile); |
| 475 | if (userfile != NULL) { |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 476 | user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); |
| 477 | if (options.strict_modes && |
| 478 | (stat(user_hostfile, &st) == 0) && |
| 479 | ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 480 | (st.st_mode & 022) != 0)) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 481 | logit("Authentication refused for %.100s: " |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 482 | "bad owner or modes for %.200s", |
| 483 | pw->pw_name, user_hostfile); |
Damien Miller | 48147d6 | 2010-06-26 09:39:25 +1000 | [diff] [blame] | 484 | auth_debug_add("Ignored %.200s: bad ownership or modes", |
| 485 | user_hostfile); |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 486 | } else { |
| 487 | temporarily_use_uid(pw); |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 488 | load_hostkeys(hostkeys, host, user_hostfile); |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 489 | restore_uid(); |
| 490 | } |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 491 | free(user_hostfile); |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 492 | } |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 493 | host_status = check_key_in_hostkeys(hostkeys, key, &found); |
| 494 | if (host_status == HOST_REVOKED) |
| 495 | error("WARNING: revoked key for %s attempted authentication", |
| 496 | found->host); |
| 497 | else if (host_status == HOST_OK) |
| 498 | debug("%s: key for %s found at %s:%ld", __func__, |
| 499 | found->host, found->file, found->line); |
| 500 | else |
| 501 | debug("%s: key for host %s not found", __func__, host); |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 502 | |
Damien Miller | d925dcd | 2010-12-01 12:21:51 +1100 | [diff] [blame] | 503 | free_hostkeys(hostkeys); |
| 504 | |
Ben Lindstrom | 83647ce | 2001-06-25 04:30:16 +0000 | [diff] [blame] | 505 | return host_status; |
| 506 | } |
| 507 | |
Damien Miller | 30da344 | 2010-05-10 11:58:03 +1000 | [diff] [blame] | 508 | static FILE * |
| 509 | auth_openfile(const char *file, struct passwd *pw, int strict_modes, |
| 510 | int log_missing, char *file_type) |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 511 | { |
| 512 | char line[1024]; |
| 513 | struct stat st; |
| 514 | int fd; |
| 515 | FILE *f; |
| 516 | |
Darren Tucker | 4355152 | 2010-01-10 19:27:17 +1100 | [diff] [blame] | 517 | if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) { |
Damien Miller | 30da344 | 2010-05-10 11:58:03 +1000 | [diff] [blame] | 518 | if (log_missing || errno != ENOENT) |
| 519 | debug("Could not open %s '%s': %s", file_type, file, |
Darren Tucker | 4355152 | 2010-01-10 19:27:17 +1100 | [diff] [blame] | 520 | strerror(errno)); |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 521 | return NULL; |
Darren Tucker | 4355152 | 2010-01-10 19:27:17 +1100 | [diff] [blame] | 522 | } |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 523 | |
| 524 | if (fstat(fd, &st) < 0) { |
| 525 | close(fd); |
| 526 | return NULL; |
| 527 | } |
| 528 | if (!S_ISREG(st.st_mode)) { |
Damien Miller | 30da344 | 2010-05-10 11:58:03 +1000 | [diff] [blame] | 529 | logit("User %s %s %s is not a regular file", |
| 530 | pw->pw_name, file_type, file); |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 531 | close(fd); |
| 532 | return NULL; |
| 533 | } |
| 534 | unset_nonblock(fd); |
| 535 | if ((f = fdopen(fd, "r")) == NULL) { |
| 536 | close(fd); |
| 537 | return NULL; |
| 538 | } |
Damien Miller | 6a740e7 | 2010-12-01 12:01:51 +1100 | [diff] [blame] | 539 | if (strict_modes && |
djm@openbsd.org | de4ae07 | 2017-08-18 05:36:45 +0000 | [diff] [blame] | 540 | safe_path_fd(fileno(f), file, pw, line, sizeof(line)) != 0) { |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 541 | fclose(f); |
| 542 | logit("Authentication refused: %s", line); |
Damien Miller | 48147d6 | 2010-06-26 09:39:25 +1000 | [diff] [blame] | 543 | auth_debug_add("Ignored %s: %s", file_type, line); |
Darren Tucker | 33c787f | 2008-07-02 22:37:30 +1000 | [diff] [blame] | 544 | return NULL; |
| 545 | } |
| 546 | |
| 547 | return f; |
| 548 | } |
| 549 | |
Damien Miller | 30da344 | 2010-05-10 11:58:03 +1000 | [diff] [blame] | 550 | |
| 551 | FILE * |
| 552 | auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes) |
| 553 | { |
| 554 | return auth_openfile(file, pw, strict_modes, 1, "authorized keys"); |
| 555 | } |
| 556 | |
| 557 | FILE * |
| 558 | auth_openprincipals(const char *file, struct passwd *pw, int strict_modes) |
| 559 | { |
| 560 | return auth_openfile(file, pw, strict_modes, 0, |
| 561 | "authorized principals"); |
| 562 | } |
| 563 | |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 564 | struct passwd * |
| 565 | getpwnamallow(const char *user) |
| 566 | { |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 567 | struct ssh *ssh = active_state; /* XXX */ |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 568 | #ifdef HAVE_LOGIN_CAP |
| 569 | extern login_cap_t *lc; |
| 570 | #ifdef BSD_AUTH |
| 571 | auth_session_t *as; |
| 572 | #endif |
| 573 | #endif |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 574 | struct passwd *pw; |
Darren Tucker | fbcf827 | 2012-05-19 19:37:01 +1000 | [diff] [blame] | 575 | struct connection_info *ci = get_connection_info(1, options.use_dns); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 576 | |
Darren Tucker | fbcf827 | 2012-05-19 19:37:01 +1000 | [diff] [blame] | 577 | ci->user = user; |
| 578 | parse_server_match_config(&options, ci); |
djm@openbsd.org | 54cd41a | 2017-05-17 01:24:17 +0000 | [diff] [blame] | 579 | log_change_level(options.log_level); |
djm@openbsd.org | dbee411 | 2017-09-12 06:32:07 +0000 | [diff] [blame] | 580 | process_permitopen(ssh, &options); |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 581 | |
Darren Tucker | b3d20a3 | 2010-03-07 11:56:59 +1100 | [diff] [blame] | 582 | #if defined(_AIX) && defined(HAVE_SETAUTHDB) |
| 583 | aix_setauthdb(user); |
| 584 | #endif |
| 585 | |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 586 | pw = getpwnam(user); |
Darren Tucker | b3d20a3 | 2010-03-07 11:56:59 +1100 | [diff] [blame] | 587 | |
| 588 | #if defined(_AIX) && defined(HAVE_SETAUTHDB) |
| 589 | aix_restoreauthdb(); |
| 590 | #endif |
Damien Miller | acc9b29 | 2010-03-01 04:36:54 +1100 | [diff] [blame] | 591 | #ifdef HAVE_CYGWIN |
| 592 | /* |
| 593 | * Windows usernames are case-insensitive. To avoid later problems |
| 594 | * when trying to match the username, the user is only allowed to |
| 595 | * login if the username is given in the same case as stored in the |
| 596 | * user database. |
| 597 | */ |
| 598 | if (pw != NULL && strcmp(user, pw->pw_name) != 0) { |
| 599 | logit("Login name %.100s does not match stored username %.100s", |
| 600 | user, pw->pw_name); |
| 601 | pw = NULL; |
| 602 | } |
| 603 | #endif |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 604 | if (pw == NULL) { |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 605 | logit("Invalid user %.100s from %.100s port %d", |
| 606 | user, ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
Darren Tucker | 97363a8 | 2003-05-02 23:42:25 +1000 | [diff] [blame] | 607 | #ifdef CUSTOM_FAILED_LOGIN |
Darren Tucker | 42d9dc7 | 2005-02-02 17:10:11 +1100 | [diff] [blame] | 608 | record_failed_login(user, |
Darren Tucker | 885fb2a | 2016-03-08 11:58:43 +1100 | [diff] [blame] | 609 | auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); |
Ben Lindstrom | f5397c0 | 2002-11-09 16:11:10 +0000 | [diff] [blame] | 610 | #endif |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 611 | #ifdef SSH_AUDIT_EVENTS |
| 612 | audit_event(SSH_INVALID_USER); |
| 613 | #endif /* SSH_AUDIT_EVENTS */ |
Damien Miller | 6f0a188 | 2002-09-22 01:26:51 +1000 | [diff] [blame] | 614 | return (NULL); |
| 615 | } |
| 616 | if (!allowed_user(pw)) |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 617 | return (NULL); |
| 618 | #ifdef HAVE_LOGIN_CAP |
| 619 | if ((lc = login_getclass(pw->pw_class)) == NULL) { |
| 620 | debug("unable to get login class: %s", user); |
| 621 | return (NULL); |
| 622 | } |
| 623 | #ifdef BSD_AUTH |
| 624 | if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || |
Damien Miller | 13e35a0 | 2002-05-22 14:04:11 +1000 | [diff] [blame] | 625 | auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 626 | debug("Approval failure for %s", user); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 627 | pw = NULL; |
Ben Lindstrom | b481e13 | 2002-03-22 01:35:47 +0000 | [diff] [blame] | 628 | } |
| 629 | if (as != NULL) |
| 630 | auth_close(as); |
| 631 | #endif |
| 632 | #endif |
Ben Lindstrom | f34e4eb | 2002-03-22 03:08:30 +0000 | [diff] [blame] | 633 | if (pw != NULL) |
| 634 | return (pwcopy(pw)); |
| 635 | return (NULL); |
Ben Lindstrom | 2ae18f4 | 2002-03-22 01:24:38 +0000 | [diff] [blame] | 636 | } |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 637 | |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 638 | /* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */ |
| 639 | int |
markus@openbsd.org | 54d90ac | 2017-05-30 08:52:19 +0000 | [diff] [blame] | 640 | auth_key_is_revoked(struct sshkey *key) |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 641 | { |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 642 | char *fp = NULL; |
| 643 | int r; |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 644 | |
| 645 | if (options.revoked_keys_file == NULL) |
| 646 | return 0; |
djm@openbsd.org | 56d1c83 | 2014-12-21 22:27:55 +0000 | [diff] [blame] | 647 | if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, |
| 648 | SSH_FP_DEFAULT)) == NULL) { |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 649 | r = SSH_ERR_ALLOC_FAIL; |
| 650 | error("%s: fingerprint key: %s", __func__, ssh_err(r)); |
| 651 | goto out; |
| 652 | } |
| 653 | |
| 654 | r = sshkey_check_revoked(key, options.revoked_keys_file); |
| 655 | switch (r) { |
Damien Miller | f3747bf | 2013-01-18 11:44:04 +1100 | [diff] [blame] | 656 | case 0: |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 657 | break; /* not revoked */ |
| 658 | case SSH_ERR_KEY_REVOKED: |
| 659 | error("Authentication key %s %s revoked by file %s", |
| 660 | sshkey_type(key), fp, options.revoked_keys_file); |
| 661 | goto out; |
Damien Miller | f3747bf | 2013-01-18 11:44:04 +1100 | [diff] [blame] | 662 | default: |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 663 | error("Error checking authentication key %s %s in " |
| 664 | "revoked keys file %s: %s", sshkey_type(key), fp, |
| 665 | options.revoked_keys_file, ssh_err(r)); |
| 666 | goto out; |
Damien Miller | f3747bf | 2013-01-18 11:44:04 +1100 | [diff] [blame] | 667 | } |
djm@openbsd.org | 5e39a49 | 2014-12-04 02:24:32 +0000 | [diff] [blame] | 668 | |
| 669 | /* Success */ |
| 670 | r = 0; |
| 671 | |
| 672 | out: |
| 673 | free(fp); |
| 674 | return r == 0 ? 0 : 1; |
Damien Miller | 1aed65e | 2010-03-04 21:53:35 +1100 | [diff] [blame] | 675 | } |
| 676 | |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 677 | void |
| 678 | auth_debug_add(const char *fmt,...) |
| 679 | { |
| 680 | char buf[1024]; |
| 681 | va_list args; |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 682 | int r; |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 683 | |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 684 | if (auth_debug == NULL) |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 685 | return; |
| 686 | |
| 687 | va_start(args, fmt); |
| 688 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 689 | va_end(args); |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 690 | if ((r = sshbuf_put_cstring(auth_debug, buf)) != 0) |
| 691 | fatal("%s: sshbuf_put_cstring: %s", __func__, ssh_err(r)); |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 692 | } |
| 693 | |
| 694 | void |
| 695 | auth_debug_send(void) |
| 696 | { |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 697 | struct ssh *ssh = active_state; /* XXX */ |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 698 | char *msg; |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 699 | int r; |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 700 | |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 701 | if (auth_debug == NULL) |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 702 | return; |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 703 | while (sshbuf_len(auth_debug) != 0) { |
| 704 | if ((r = sshbuf_get_cstring(auth_debug, &msg, NULL)) != 0) |
| 705 | fatal("%s: sshbuf_get_cstring: %s", |
| 706 | __func__, ssh_err(r)); |
| 707 | ssh_packet_send_debug(ssh, "%s", msg); |
Darren Tucker | a627d42 | 2013-06-02 07:31:17 +1000 | [diff] [blame] | 708 | free(msg); |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 709 | } |
| 710 | } |
| 711 | |
| 712 | void |
| 713 | auth_debug_reset(void) |
| 714 | { |
markus@openbsd.org | c7d39ac | 2018-07-09 21:35:50 +0000 | [diff] [blame] | 715 | if (auth_debug != NULL) |
| 716 | sshbuf_reset(auth_debug); |
| 717 | else if ((auth_debug = sshbuf_new()) == NULL) |
| 718 | fatal("%s: sshbuf_new failed", __func__); |
Ben Lindstrom | a574cda | 2002-05-15 16:16:14 +0000 | [diff] [blame] | 719 | } |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 720 | |
| 721 | struct passwd * |
| 722 | fakepw(void) |
| 723 | { |
| 724 | static struct passwd fake; |
| 725 | |
| 726 | memset(&fake, 0, sizeof(fake)); |
| 727 | fake.pw_name = "NOUSER"; |
| 728 | fake.pw_passwd = |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 729 | "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; |
Damien Miller | 6332da2 | 2013-04-23 14:25:52 +1000 | [diff] [blame] | 730 | #ifdef HAVE_STRUCT_PASSWD_PW_GECOS |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 731 | fake.pw_gecos = "NOUSER"; |
Damien Miller | 6332da2 | 2013-04-23 14:25:52 +1000 | [diff] [blame] | 732 | #endif |
Damien Miller | 143c2ef | 2006-12-05 09:08:54 +1100 | [diff] [blame] | 733 | fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid; |
| 734 | fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid; |
Damien Miller | 6332da2 | 2013-04-23 14:25:52 +1000 | [diff] [blame] | 735 | #ifdef HAVE_STRUCT_PASSWD_PW_CLASS |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 736 | fake.pw_class = ""; |
| 737 | #endif |
| 738 | fake.pw_dir = "/nonexist"; |
| 739 | fake.pw_shell = "/nonexist"; |
| 740 | |
| 741 | return (&fake); |
| 742 | } |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 743 | |
| 744 | /* |
| 745 | * Returns the remote DNS hostname as a string. The returned string must not |
| 746 | * be freed. NB. this will usually trigger a DNS query the first time it is |
| 747 | * called. |
| 748 | * This function does additional checks on the hostname to mitigate some |
| 749 | * attacks on legacy rhosts-style authentication. |
| 750 | * XXX is RhostsRSAAuthentication vulnerable to these? |
| 751 | * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?) |
| 752 | */ |
| 753 | |
| 754 | static char * |
| 755 | remote_hostname(struct ssh *ssh) |
| 756 | { |
| 757 | struct sockaddr_storage from; |
| 758 | socklen_t fromlen; |
| 759 | struct addrinfo hints, *ai, *aitop; |
| 760 | char name[NI_MAXHOST], ntop2[NI_MAXHOST]; |
| 761 | const char *ntop = ssh_remote_ipaddr(ssh); |
| 762 | |
| 763 | /* Get IP address of client. */ |
| 764 | fromlen = sizeof(from); |
| 765 | memset(&from, 0, sizeof(from)); |
| 766 | if (getpeername(ssh_packet_get_connection_in(ssh), |
| 767 | (struct sockaddr *)&from, &fromlen) < 0) { |
| 768 | debug("getpeername failed: %.100s", strerror(errno)); |
| 769 | return strdup(ntop); |
| 770 | } |
| 771 | |
| 772 | ipv64_normalise_mapped(&from, &fromlen); |
| 773 | if (from.ss_family == AF_INET6) |
| 774 | fromlen = sizeof(struct sockaddr_in6); |
| 775 | |
| 776 | debug3("Trying to reverse map address %.100s.", ntop); |
| 777 | /* Map the IP address to a host name. */ |
| 778 | if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), |
| 779 | NULL, 0, NI_NAMEREQD) != 0) { |
| 780 | /* Host name not found. Use ip address. */ |
| 781 | return strdup(ntop); |
| 782 | } |
| 783 | |
| 784 | /* |
| 785 | * if reverse lookup result looks like a numeric hostname, |
| 786 | * someone is trying to trick us by PTR record like following: |
| 787 | * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 |
| 788 | */ |
| 789 | memset(&hints, 0, sizeof(hints)); |
| 790 | hints.ai_socktype = SOCK_DGRAM; /*dummy*/ |
| 791 | hints.ai_flags = AI_NUMERICHOST; |
| 792 | if (getaddrinfo(name, NULL, &hints, &ai) == 0) { |
| 793 | logit("Nasty PTR record \"%s\" is set up for %s, ignoring", |
| 794 | name, ntop); |
| 795 | freeaddrinfo(ai); |
| 796 | return strdup(ntop); |
| 797 | } |
| 798 | |
| 799 | /* Names are stored in lowercase. */ |
| 800 | lowercase(name); |
| 801 | |
| 802 | /* |
| 803 | * Map it back to an IP address and check that the given |
| 804 | * address actually is an address of this host. This is |
| 805 | * necessary because anyone with access to a name server can |
| 806 | * define arbitrary names for an IP address. Mapping from |
| 807 | * name to IP address can be trusted better (but can still be |
| 808 | * fooled if the intruder has access to the name server of |
| 809 | * the domain). |
| 810 | */ |
| 811 | memset(&hints, 0, sizeof(hints)); |
| 812 | hints.ai_family = from.ss_family; |
| 813 | hints.ai_socktype = SOCK_STREAM; |
| 814 | if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { |
| 815 | logit("reverse mapping checking getaddrinfo for %.700s " |
dtucker@openbsd.org | e690fe8 | 2016-06-15 00:40:40 +0000 | [diff] [blame] | 816 | "[%s] failed.", name, ntop); |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 817 | return strdup(ntop); |
| 818 | } |
| 819 | /* Look for the address from the list of addresses. */ |
| 820 | for (ai = aitop; ai; ai = ai->ai_next) { |
| 821 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2, |
| 822 | sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 && |
| 823 | (strcmp(ntop, ntop2) == 0)) |
| 824 | break; |
| 825 | } |
| 826 | freeaddrinfo(aitop); |
| 827 | /* If we reached the end of the list, the address was not there. */ |
| 828 | if (ai == NULL) { |
| 829 | /* Address not found for the host name. */ |
| 830 | logit("Address %.100s maps to %.600s, but this does not " |
dtucker@openbsd.org | e690fe8 | 2016-06-15 00:40:40 +0000 | [diff] [blame] | 831 | "map back to the address.", ntop, name); |
djm@openbsd.org | 9576726 | 2016-03-07 19:02:43 +0000 | [diff] [blame] | 832 | return strdup(ntop); |
| 833 | } |
| 834 | return strdup(name); |
| 835 | } |
| 836 | |
| 837 | /* |
| 838 | * Return the canonical name of the host in the other side of the current |
| 839 | * connection. The host name is cached, so it is efficient to call this |
| 840 | * several times. |
| 841 | */ |
| 842 | |
| 843 | const char * |
| 844 | auth_get_canonical_hostname(struct ssh *ssh, int use_dns) |
| 845 | { |
| 846 | static char *dnsname; |
| 847 | |
| 848 | if (!use_dns) |
| 849 | return ssh_remote_ipaddr(ssh); |
| 850 | else if (dnsname != NULL) |
| 851 | return dnsname; |
| 852 | else { |
| 853 | dnsname = remote_hostname(ssh); |
| 854 | return dnsname; |
| 855 | } |
| 856 | } |
markus@openbsd.org | 25cf910 | 2018-01-08 15:21:49 +0000 | [diff] [blame] | 857 | |
| 858 | /* |
martijn@openbsd.org | 5dc4c59 | 2018-07-11 08:19:35 +0000 | [diff] [blame] | 859 | * Runs command in a subprocess with a minimal environment. |
markus@openbsd.org | 25cf910 | 2018-01-08 15:21:49 +0000 | [diff] [blame] | 860 | * Returns pid on success, 0 on failure. |
| 861 | * The child stdout and stderr maybe captured, left attached or sent to |
| 862 | * /dev/null depending on the contents of flags. |
| 863 | * "tag" is prepended to log messages. |
| 864 | * NB. "command" is only used for logging; the actual command executed is |
| 865 | * av[0]. |
| 866 | */ |
| 867 | pid_t |
| 868 | subprocess(const char *tag, struct passwd *pw, const char *command, |
| 869 | int ac, char **av, FILE **child, u_int flags) |
| 870 | { |
| 871 | FILE *f = NULL; |
| 872 | struct stat st; |
| 873 | int fd, devnull, p[2], i; |
| 874 | pid_t pid; |
| 875 | char *cp, errmsg[512]; |
| 876 | u_int envsize; |
| 877 | char **child_env; |
| 878 | |
| 879 | if (child != NULL) |
| 880 | *child = NULL; |
| 881 | |
| 882 | debug3("%s: %s command \"%s\" running as %s (flags 0x%x)", __func__, |
| 883 | tag, command, pw->pw_name, flags); |
| 884 | |
| 885 | /* Check consistency */ |
| 886 | if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && |
| 887 | (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { |
| 888 | error("%s: inconsistent flags", __func__); |
| 889 | return 0; |
| 890 | } |
| 891 | if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { |
| 892 | error("%s: inconsistent flags/output", __func__); |
| 893 | return 0; |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * If executing an explicit binary, then verify the it exists |
| 898 | * and appears safe-ish to execute |
| 899 | */ |
djm@openbsd.org | 2a35862 | 2018-11-16 03:26:01 +0000 | [diff] [blame] | 900 | if (!path_absolute(av[0])) { |
markus@openbsd.org | 25cf910 | 2018-01-08 15:21:49 +0000 | [diff] [blame] | 901 | error("%s path is not absolute", tag); |
| 902 | return 0; |
| 903 | } |
| 904 | temporarily_use_uid(pw); |
| 905 | if (stat(av[0], &st) < 0) { |
| 906 | error("Could not stat %s \"%s\": %s", tag, |
| 907 | av[0], strerror(errno)); |
| 908 | restore_uid(); |
| 909 | return 0; |
| 910 | } |
| 911 | if (safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { |
| 912 | error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); |
| 913 | restore_uid(); |
| 914 | return 0; |
| 915 | } |
| 916 | /* Prepare to keep the child's stdout if requested */ |
| 917 | if (pipe(p) != 0) { |
| 918 | error("%s: pipe: %s", tag, strerror(errno)); |
| 919 | restore_uid(); |
| 920 | return 0; |
| 921 | } |
| 922 | restore_uid(); |
| 923 | |
| 924 | switch ((pid = fork())) { |
| 925 | case -1: /* error */ |
| 926 | error("%s: fork: %s", tag, strerror(errno)); |
| 927 | close(p[0]); |
| 928 | close(p[1]); |
| 929 | return 0; |
| 930 | case 0: /* child */ |
| 931 | /* Prepare a minimal environment for the child. */ |
| 932 | envsize = 5; |
| 933 | child_env = xcalloc(sizeof(*child_env), envsize); |
| 934 | child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH); |
| 935 | child_set_env(&child_env, &envsize, "USER", pw->pw_name); |
| 936 | child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name); |
| 937 | child_set_env(&child_env, &envsize, "HOME", pw->pw_dir); |
| 938 | if ((cp = getenv("LANG")) != NULL) |
| 939 | child_set_env(&child_env, &envsize, "LANG", cp); |
| 940 | |
| 941 | for (i = 0; i < NSIG; i++) |
| 942 | signal(i, SIG_DFL); |
| 943 | |
| 944 | if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { |
| 945 | error("%s: open %s: %s", tag, _PATH_DEVNULL, |
| 946 | strerror(errno)); |
| 947 | _exit(1); |
| 948 | } |
| 949 | if (dup2(devnull, STDIN_FILENO) == -1) { |
| 950 | error("%s: dup2: %s", tag, strerror(errno)); |
| 951 | _exit(1); |
| 952 | } |
| 953 | |
| 954 | /* Set up stdout as requested; leave stderr in place for now. */ |
| 955 | fd = -1; |
| 956 | if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) |
| 957 | fd = p[1]; |
| 958 | else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) |
| 959 | fd = devnull; |
| 960 | if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { |
| 961 | error("%s: dup2: %s", tag, strerror(errno)); |
| 962 | _exit(1); |
| 963 | } |
| 964 | closefrom(STDERR_FILENO + 1); |
| 965 | |
| 966 | /* Don't use permanently_set_uid() here to avoid fatal() */ |
| 967 | if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) { |
| 968 | error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, |
| 969 | strerror(errno)); |
| 970 | _exit(1); |
| 971 | } |
| 972 | if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) { |
| 973 | error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, |
| 974 | strerror(errno)); |
| 975 | _exit(1); |
| 976 | } |
| 977 | /* stdin is pointed to /dev/null at this point */ |
| 978 | if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && |
| 979 | dup2(STDIN_FILENO, STDERR_FILENO) == -1) { |
| 980 | error("%s: dup2: %s", tag, strerror(errno)); |
| 981 | _exit(1); |
| 982 | } |
| 983 | |
| 984 | execve(av[0], av, child_env); |
| 985 | error("%s exec \"%s\": %s", tag, command, strerror(errno)); |
| 986 | _exit(127); |
| 987 | default: /* parent */ |
| 988 | break; |
| 989 | } |
| 990 | |
| 991 | close(p[1]); |
| 992 | if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) |
| 993 | close(p[0]); |
| 994 | else if ((f = fdopen(p[0], "r")) == NULL) { |
| 995 | error("%s: fdopen: %s", tag, strerror(errno)); |
| 996 | close(p[0]); |
| 997 | /* Don't leave zombie child */ |
| 998 | kill(pid, SIGTERM); |
| 999 | while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) |
| 1000 | ; |
| 1001 | return 0; |
| 1002 | } |
| 1003 | /* Success */ |
| 1004 | debug3("%s: %s pid %ld", __func__, tag, (long)pid); |
| 1005 | if (child != NULL) |
| 1006 | *child = f; |
| 1007 | return pid; |
| 1008 | } |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1009 | |
| 1010 | /* These functions link key/cert options to the auth framework */ |
| 1011 | |
| 1012 | /* Log sshauthopt options locally and (optionally) for remote transmission */ |
| 1013 | void |
| 1014 | auth_log_authopts(const char *loc, const struct sshauthopt *opts, int do_remote) |
| 1015 | { |
| 1016 | int do_env = options.permit_user_env && opts->nenv > 0; |
| 1017 | int do_permitopen = opts->npermitopen > 0 && |
| 1018 | (options.allow_tcp_forwarding & FORWARD_LOCAL) != 0; |
djm@openbsd.org | 93c06ab | 2018-06-06 18:23:32 +0000 | [diff] [blame] | 1019 | int do_permitlisten = opts->npermitlisten > 0 && |
| 1020 | (options.allow_tcp_forwarding & FORWARD_REMOTE) != 0; |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1021 | size_t i; |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1022 | char msg[1024], buf[64]; |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1023 | |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1024 | snprintf(buf, sizeof(buf), "%d", opts->force_tun_device); |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1025 | /* Try to keep this alphabetically sorted */ |
djm@openbsd.org | 93c06ab | 2018-06-06 18:23:32 +0000 | [diff] [blame] | 1026 | snprintf(msg, sizeof(msg), "key options:%s%s%s%s%s%s%s%s%s%s%s%s%s", |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1027 | opts->permit_agent_forwarding_flag ? " agent-forwarding" : "", |
| 1028 | opts->force_command == NULL ? "" : " command", |
| 1029 | do_env ? " environment" : "", |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1030 | opts->valid_before == 0 ? "" : "expires", |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1031 | do_permitopen ? " permitopen" : "", |
djm@openbsd.org | 93c06ab | 2018-06-06 18:23:32 +0000 | [diff] [blame] | 1032 | do_permitlisten ? " permitlisten" : "", |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1033 | opts->permit_port_forwarding_flag ? " port-forwarding" : "", |
| 1034 | opts->cert_principals == NULL ? "" : " principals", |
| 1035 | opts->permit_pty_flag ? " pty" : "", |
| 1036 | opts->force_tun_device == -1 ? "" : " tun=", |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1037 | opts->force_tun_device == -1 ? "" : buf, |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1038 | opts->permit_user_rc ? " user-rc" : "", |
| 1039 | opts->permit_x11_forwarding_flag ? " x11-forwarding" : ""); |
| 1040 | |
| 1041 | debug("%s: %s", loc, msg); |
| 1042 | if (do_remote) |
| 1043 | auth_debug_add("%s: %s", loc, msg); |
| 1044 | |
| 1045 | if (options.permit_user_env) { |
| 1046 | for (i = 0; i < opts->nenv; i++) { |
| 1047 | debug("%s: environment: %s", loc, opts->env[i]); |
| 1048 | if (do_remote) { |
| 1049 | auth_debug_add("%s: environment: %s", |
| 1050 | loc, opts->env[i]); |
| 1051 | } |
| 1052 | } |
| 1053 | } |
| 1054 | |
| 1055 | /* Go into a little more details for the local logs. */ |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1056 | if (opts->valid_before != 0) { |
| 1057 | format_absolute_time(opts->valid_before, buf, sizeof(buf)); |
| 1058 | debug("%s: expires at %s", loc, buf); |
| 1059 | } |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1060 | if (opts->cert_principals != NULL) { |
| 1061 | debug("%s: authorized principals: \"%s\"", |
| 1062 | loc, opts->cert_principals); |
| 1063 | } |
| 1064 | if (opts->force_command != NULL) |
| 1065 | debug("%s: forced command: \"%s\"", loc, opts->force_command); |
djm@openbsd.org | 93c06ab | 2018-06-06 18:23:32 +0000 | [diff] [blame] | 1066 | if (do_permitopen) { |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1067 | for (i = 0; i < opts->npermitopen; i++) { |
| 1068 | debug("%s: permitted open: %s", |
| 1069 | loc, opts->permitopen[i]); |
| 1070 | } |
| 1071 | } |
djm@openbsd.org | 93c06ab | 2018-06-06 18:23:32 +0000 | [diff] [blame] | 1072 | if (do_permitlisten) { |
| 1073 | for (i = 0; i < opts->npermitlisten; i++) { |
| 1074 | debug("%s: permitted listen: %s", |
| 1075 | loc, opts->permitlisten[i]); |
| 1076 | } |
| 1077 | } |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1078 | } |
| 1079 | |
| 1080 | /* Activate a new set of key/cert options; merging with what is there. */ |
| 1081 | int |
| 1082 | auth_activate_options(struct ssh *ssh, struct sshauthopt *opts) |
| 1083 | { |
| 1084 | struct sshauthopt *old = auth_opts; |
| 1085 | const char *emsg = NULL; |
| 1086 | |
| 1087 | debug("%s: setting new authentication options", __func__); |
| 1088 | if ((auth_opts = sshauthopt_merge(old, opts, &emsg)) == NULL) { |
| 1089 | error("Inconsistent authentication options: %s", emsg); |
| 1090 | return -1; |
| 1091 | } |
| 1092 | return 0; |
| 1093 | } |
| 1094 | |
| 1095 | /* Disable forwarding, etc for the session */ |
| 1096 | void |
| 1097 | auth_restrict_session(struct ssh *ssh) |
| 1098 | { |
| 1099 | struct sshauthopt *restricted; |
| 1100 | |
| 1101 | debug("%s: restricting session", __func__); |
| 1102 | |
| 1103 | /* A blank sshauthopt defaults to permitting nothing */ |
| 1104 | restricted = sshauthopt_new(); |
djm@openbsd.org | fbb4b5f | 2018-05-25 07:11:01 +0000 | [diff] [blame] | 1105 | restricted->permit_pty_flag = 1; |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1106 | restricted->restricted = 1; |
| 1107 | |
| 1108 | if (auth_activate_options(ssh, restricted) != 0) |
| 1109 | fatal("%s: failed to restrict session", __func__); |
| 1110 | sshauthopt_free(restricted); |
| 1111 | } |
| 1112 | |
| 1113 | int |
| 1114 | auth_authorise_keyopts(struct ssh *ssh, struct passwd *pw, |
| 1115 | struct sshauthopt *opts, int allow_cert_authority, const char *loc) |
| 1116 | { |
| 1117 | const char *remote_ip = ssh_remote_ipaddr(ssh); |
| 1118 | const char *remote_host = auth_get_canonical_hostname(ssh, |
| 1119 | options.use_dns); |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1120 | time_t now = time(NULL); |
| 1121 | char buf[64]; |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1122 | |
djm@openbsd.org | bf0fbf2 | 2018-03-12 00:52:01 +0000 | [diff] [blame] | 1123 | /* |
| 1124 | * Check keys/principals file expiry time. |
| 1125 | * NB. validity interval in certificate is handled elsewhere. |
| 1126 | */ |
| 1127 | if (opts->valid_before && now > 0 && |
| 1128 | opts->valid_before < (uint64_t)now) { |
| 1129 | format_absolute_time(opts->valid_before, buf, sizeof(buf)); |
| 1130 | debug("%s: entry expired at %s", loc, buf); |
| 1131 | auth_debug_add("%s: entry expired at %s", loc, buf); |
| 1132 | return -1; |
| 1133 | } |
djm@openbsd.org | 7c85685 | 2018-03-03 03:15:51 +0000 | [diff] [blame] | 1134 | /* Consistency checks */ |
| 1135 | if (opts->cert_principals != NULL && !opts->cert_authority) { |
| 1136 | debug("%s: principals on non-CA key", loc); |
| 1137 | auth_debug_add("%s: principals on non-CA key", loc); |
| 1138 | /* deny access */ |
| 1139 | return -1; |
| 1140 | } |
| 1141 | /* cert-authority flag isn't valid in authorized_principals files */ |
| 1142 | if (!allow_cert_authority && opts->cert_authority) { |
| 1143 | debug("%s: cert-authority flag invalid here", loc); |
| 1144 | auth_debug_add("%s: cert-authority flag invalid here", loc); |
| 1145 | /* deny access */ |
| 1146 | return -1; |
| 1147 | } |
| 1148 | |
| 1149 | /* Perform from= checks */ |
| 1150 | if (opts->required_from_host_keys != NULL) { |
| 1151 | switch (match_host_and_ip(remote_host, remote_ip, |
| 1152 | opts->required_from_host_keys )) { |
| 1153 | case 1: |
| 1154 | /* Host name matches. */ |
| 1155 | break; |
| 1156 | case -1: |
| 1157 | default: |
| 1158 | debug("%s: invalid from criteria", loc); |
| 1159 | auth_debug_add("%s: invalid from criteria", loc); |
| 1160 | /* FALLTHROUGH */ |
| 1161 | case 0: |
| 1162 | logit("%s: Authentication tried for %.100s with " |
| 1163 | "correct key but not from a permitted " |
| 1164 | "host (host=%.200s, ip=%.200s, required=%.200s).", |
| 1165 | loc, pw->pw_name, remote_host, remote_ip, |
| 1166 | opts->required_from_host_keys); |
| 1167 | auth_debug_add("%s: Your host '%.200s' is not " |
| 1168 | "permitted to use this key for login.", |
| 1169 | loc, remote_host); |
| 1170 | /* deny access */ |
| 1171 | return -1; |
| 1172 | } |
| 1173 | } |
| 1174 | /* Check source-address restriction from certificate */ |
| 1175 | if (opts->required_from_host_cert != NULL) { |
| 1176 | switch (addr_match_cidr_list(remote_ip, |
| 1177 | opts->required_from_host_cert)) { |
| 1178 | case 1: |
| 1179 | /* accepted */ |
| 1180 | break; |
| 1181 | case -1: |
| 1182 | default: |
| 1183 | /* invalid */ |
| 1184 | error("%s: Certificate source-address invalid", |
| 1185 | loc); |
| 1186 | /* FALLTHROUGH */ |
| 1187 | case 0: |
| 1188 | logit("%s: Authentication tried for %.100s with valid " |
| 1189 | "certificate but not from a permitted source " |
| 1190 | "address (%.200s).", loc, pw->pw_name, remote_ip); |
| 1191 | auth_debug_add("%s: Your address '%.200s' is not " |
| 1192 | "permitted to use this certificate for login.", |
| 1193 | loc, remote_ip); |
| 1194 | return -1; |
| 1195 | } |
| 1196 | } |
| 1197 | /* |
| 1198 | * |
| 1199 | * XXX this is spammy. We should report remotely only for keys |
| 1200 | * that are successful in actual auth attempts, and not PK_OK |
| 1201 | * tests. |
| 1202 | */ |
| 1203 | auth_log_authopts(loc, opts, 1); |
| 1204 | |
| 1205 | return 0; |
| 1206 | } |