Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 1 | /* $OpenBSD: auth2.c,v 1.125 2012/11/04 11:09:15 djm Exp $ */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2000 Markus Friedl. All rights reserved. |
| 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. |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 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. |
| 24 | */ |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 25 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 26 | #include "includes.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 27 | |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 28 | #include <sys/types.h> |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 29 | #include <sys/stat.h> |
| 30 | #include <sys/uio.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 31 | |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 32 | #include <fcntl.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 33 | #include <pwd.h> |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 34 | #include <stdarg.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 35 | #include <string.h> |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 36 | #include <unistd.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 37 | |
Damien Miller | 0b4d48b | 2008-07-05 09:44:53 +1000 | [diff] [blame] | 38 | #include "atomicio.h" |
Darren Tucker | 43e7a35 | 2009-06-21 19:50:08 +1000 | [diff] [blame] | 39 | #include "xmalloc.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 40 | #include "ssh2.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 41 | #include "packet.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 42 | #include "log.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 43 | #include "buffer.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 44 | #include "servconf.h" |
| 45 | #include "compat.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 46 | #include "key.h" |
| 47 | #include "hostfile.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 48 | #include "auth.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 49 | #include "dispatch.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 50 | #include "pathnames.h" |
Darren Tucker | 77fc29e | 2004-09-11 23:07:03 +1000 | [diff] [blame] | 51 | #include "buffer.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 52 | |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 53 | #ifdef GSSAPI |
| 54 | #include "ssh-gss.h" |
| 55 | #endif |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 56 | #include "monitor_wrap.h" |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 57 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 58 | /* import */ |
| 59 | extern ServerOptions options; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 60 | extern u_char *session_id2; |
Darren Tucker | 502d384 | 2003-06-28 12:38:01 +1000 | [diff] [blame] | 61 | extern u_int session_id2_len; |
Darren Tucker | 77fc29e | 2004-09-11 23:07:03 +1000 | [diff] [blame] | 62 | extern Buffer loginmsg; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 63 | |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 64 | /* methods */ |
| 65 | |
| 66 | extern Authmethod method_none; |
| 67 | extern Authmethod method_pubkey; |
| 68 | extern Authmethod method_passwd; |
| 69 | extern Authmethod method_kbdint; |
| 70 | extern Authmethod method_hostbased; |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 71 | #ifdef GSSAPI |
| 72 | extern Authmethod method_gssapi; |
| 73 | #endif |
Damien Miller | 01ed227 | 2008-11-05 16:20:46 +1100 | [diff] [blame] | 74 | #ifdef JPAKE |
| 75 | extern Authmethod method_jpake; |
| 76 | #endif |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 77 | |
| 78 | Authmethod *authmethods[] = { |
| 79 | &method_none, |
| 80 | &method_pubkey, |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 81 | #ifdef GSSAPI |
| 82 | &method_gssapi, |
| 83 | #endif |
Damien Miller | 01ed227 | 2008-11-05 16:20:46 +1100 | [diff] [blame] | 84 | #ifdef JPAKE |
| 85 | &method_jpake, |
| 86 | #endif |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 87 | &method_passwd, |
| 88 | &method_kbdint, |
| 89 | &method_hostbased, |
| 90 | NULL |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 91 | }; |
| 92 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 93 | /* protocol */ |
| 94 | |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 95 | static void input_service_request(int, u_int32_t, void *); |
| 96 | static void input_userauth_request(int, u_int32_t, void *); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 97 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 98 | /* helper */ |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 99 | static Authmethod *authmethod_lookup(Authctxt *, const char *); |
| 100 | static char *authmethods_get(Authctxt *authctxt); |
| 101 | static int method_allowed(Authctxt *, const char *); |
| 102 | static int list_starts_with(const char *, const char *); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 103 | |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 104 | char * |
| 105 | auth2_read_banner(void) |
| 106 | { |
| 107 | struct stat st; |
| 108 | char *banner = NULL; |
| 109 | size_t len, n; |
| 110 | int fd; |
| 111 | |
| 112 | if ((fd = open(options.banner, O_RDONLY)) == -1) |
| 113 | return (NULL); |
| 114 | if (fstat(fd, &st) == -1) { |
| 115 | close(fd); |
| 116 | return (NULL); |
| 117 | } |
Damien Miller | 8ed4de8 | 2011-12-19 10:52:50 +1100 | [diff] [blame] | 118 | if (st.st_size <= 0 || st.st_size > 1*1024*1024) { |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 119 | close(fd); |
| 120 | return (NULL); |
| 121 | } |
| 122 | |
| 123 | len = (size_t)st.st_size; /* truncate */ |
| 124 | banner = xmalloc(len + 1); |
| 125 | n = atomicio(read, fd, banner, len); |
| 126 | close(fd); |
| 127 | |
| 128 | if (n != len) { |
| 129 | xfree(banner); |
| 130 | return (NULL); |
| 131 | } |
| 132 | banner[n] = '\0'; |
| 133 | |
| 134 | return (banner); |
| 135 | } |
| 136 | |
| 137 | void |
| 138 | userauth_send_banner(const char *msg) |
| 139 | { |
| 140 | if (datafellows & SSH_BUG_BANNER) |
| 141 | return; |
| 142 | |
| 143 | packet_start(SSH2_MSG_USERAUTH_BANNER); |
| 144 | packet_put_cstring(msg); |
| 145 | packet_put_cstring(""); /* language, unused */ |
| 146 | packet_send(); |
| 147 | debug("%s: sent", __func__); |
| 148 | } |
| 149 | |
| 150 | static void |
| 151 | userauth_banner(void) |
| 152 | { |
| 153 | char *banner = NULL; |
| 154 | |
| 155 | if (options.banner == NULL || |
| 156 | strcasecmp(options.banner, "none") == 0 || |
| 157 | (datafellows & SSH_BUG_BANNER) != 0) |
| 158 | return; |
| 159 | |
| 160 | if ((banner = PRIVSEP(auth2_read_banner())) == NULL) |
| 161 | goto done; |
| 162 | userauth_send_banner(banner); |
| 163 | |
| 164 | done: |
| 165 | if (banner) |
| 166 | xfree(banner); |
| 167 | } |
| 168 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 169 | /* |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 170 | * loop until authctxt->success == TRUE |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 171 | */ |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 172 | void |
| 173 | do_authentication2(Authctxt *authctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 174 | { |
Damien Miller | 7d05339 | 2002-01-22 23:24:13 +1100 | [diff] [blame] | 175 | dispatch_init(&dispatch_protocol_error); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 176 | dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 177 | dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 178 | } |
| 179 | |
Damien Miller | 91d4b12 | 2006-03-26 14:05:20 +1100 | [diff] [blame] | 180 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 181 | static void |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 182 | input_service_request(int type, u_int32_t seq, void *ctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 183 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 184 | Authctxt *authctxt = ctxt; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 185 | u_int len; |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 186 | int acceptit = 0; |
Damien Miller | da108ec | 2010-08-31 22:36:39 +1000 | [diff] [blame] | 187 | char *service = packet_get_cstring(&len); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 188 | packet_check_eom(); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 189 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 190 | if (authctxt == NULL) |
| 191 | fatal("input_service_request: no authctxt"); |
| 192 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 193 | if (strcmp(service, "ssh-userauth") == 0) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 194 | if (!authctxt->success) { |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 195 | acceptit = 1; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 196 | /* now we can handle user-auth requests */ |
| 197 | dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); |
| 198 | } |
| 199 | } |
| 200 | /* XXX all other service requests are denied */ |
| 201 | |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 202 | if (acceptit) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 203 | packet_start(SSH2_MSG_SERVICE_ACCEPT); |
| 204 | packet_put_cstring(service); |
| 205 | packet_send(); |
| 206 | packet_write_wait(); |
| 207 | } else { |
| 208 | debug("bad service request %s", service); |
| 209 | packet_disconnect("bad service request %s", service); |
| 210 | } |
| 211 | xfree(service); |
| 212 | } |
| 213 | |
Damien Miller | 91d4b12 | 2006-03-26 14:05:20 +1100 | [diff] [blame] | 214 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 215 | static void |
Damien Miller | 630d6f4 | 2002-01-22 23:17:30 +1100 | [diff] [blame] | 216 | input_userauth_request(int type, u_int32_t seq, void *ctxt) |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 217 | { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 218 | Authctxt *authctxt = ctxt; |
| 219 | Authmethod *m = NULL; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 220 | char *user, *service, *method, *style = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 221 | int authenticated = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 222 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 223 | if (authctxt == NULL) |
| 224 | fatal("input_userauth_request: no authctxt"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 225 | |
Damien Miller | da108ec | 2010-08-31 22:36:39 +1000 | [diff] [blame] | 226 | user = packet_get_cstring(NULL); |
| 227 | service = packet_get_cstring(NULL); |
| 228 | method = packet_get_cstring(NULL); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 229 | debug("userauth-request for user %s service %s method %s", user, service, method); |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 230 | debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 231 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 232 | if ((style = strchr(user, ':')) != NULL) |
| 233 | *style++ = 0; |
| 234 | |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 235 | if (authctxt->attempt++ == 0) { |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 236 | /* setup auth context */ |
Kevin Steves | 205cc1e | 2002-03-22 20:43:05 +0000 | [diff] [blame] | 237 | authctxt->pw = PRIVSEP(getpwnamallow(user)); |
Darren Tucker | dbf7a74 | 2004-03-08 23:04:06 +1100 | [diff] [blame] | 238 | authctxt->user = xstrdup(user); |
Kevin Steves | 205cc1e | 2002-03-22 20:43:05 +0000 | [diff] [blame] | 239 | if (authctxt->pw && strcmp(service, "ssh-connection")==0) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 240 | authctxt->valid = 1; |
| 241 | debug2("input_userauth_request: setting up authctxt for %s", user); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 242 | } else { |
Darren Tucker | 5cb30ad | 2004-08-12 22:40:24 +1000 | [diff] [blame] | 243 | logit("input_userauth_request: invalid user %s", user); |
Damien Miller | 856f0be | 2003-09-03 07:32:45 +1000 | [diff] [blame] | 244 | authctxt->pw = fakepw(); |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 245 | #ifdef SSH_AUDIT_EVENTS |
| 246 | PRIVSEP(audit_event(SSH_INVALID_USER)); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 247 | #endif |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 248 | } |
Darren Tucker | d3eff2b | 2005-09-24 12:43:51 +1000 | [diff] [blame] | 249 | #ifdef USE_PAM |
| 250 | if (options.use_pam) |
| 251 | PRIVSEP(start_pam(authctxt)); |
| 252 | #endif |
Damien Miller | 30d1f84 | 2004-07-21 20:48:53 +1000 | [diff] [blame] | 253 | setproctitle("%s%s", authctxt->valid ? user : "unknown", |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 254 | use_privsep ? " [net]" : ""); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 255 | authctxt->service = xstrdup(service); |
Ben Lindstrom | 9d0c066 | 2001-06-09 01:40:00 +0000 | [diff] [blame] | 256 | authctxt->style = style ? xstrdup(style) : NULL; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 257 | if (use_privsep) |
| 258 | mm_inform_authserv(service, style); |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 259 | userauth_banner(); |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 260 | if (auth2_setup_methods_lists(authctxt) != 0) |
| 261 | packet_disconnect("no authentication methods enabled"); |
Ben Lindstrom | 9d0c066 | 2001-06-09 01:40:00 +0000 | [diff] [blame] | 262 | } else if (strcmp(user, authctxt->user) != 0 || |
| 263 | strcmp(service, authctxt->service) != 0) { |
| 264 | packet_disconnect("Change of username or service not allowed: " |
| 265 | "(%s,%s) -> (%s,%s)", |
| 266 | authctxt->user, authctxt->service, user, service); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 267 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 268 | /* reset state */ |
Damien Miller | ee11625 | 2001-12-21 12:42:34 +1100 | [diff] [blame] | 269 | auth2_challenge_stop(authctxt); |
Damien Miller | 01ed227 | 2008-11-05 16:20:46 +1100 | [diff] [blame] | 270 | #ifdef JPAKE |
| 271 | auth2_jpake_stop(authctxt); |
| 272 | #endif |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 273 | |
| 274 | #ifdef GSSAPI |
Damien Miller | 01ed227 | 2008-11-05 16:20:46 +1100 | [diff] [blame] | 275 | /* XXX move to auth2_gssapi_stop() */ |
Darren Tucker | 0efd155 | 2003-08-26 11:49:55 +1000 | [diff] [blame] | 276 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); |
| 277 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL); |
| 278 | #endif |
| 279 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 280 | authctxt->postponed = 0; |
Damien Miller | 3fcdfd5 | 2011-05-05 14:04:11 +1000 | [diff] [blame] | 281 | authctxt->server_caused_failure = 0; |
Damien Miller | b70b61f | 2000-09-16 16:25:12 +1100 | [diff] [blame] | 282 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 283 | /* try to authenticate user */ |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 284 | m = authmethod_lookup(authctxt, method); |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 285 | if (m != NULL && authctxt->failures < options.max_authtries) { |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 286 | debug2("input_userauth_request: try method %s", method); |
| 287 | authenticated = m->userauth(authctxt); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 288 | } |
Damien Miller | 5d57e50 | 2001-03-30 10:48:31 +1000 | [diff] [blame] | 289 | userauth_finish(authctxt, authenticated, method); |
| 290 | |
| 291 | xfree(service); |
| 292 | xfree(user); |
| 293 | xfree(method); |
| 294 | } |
| 295 | |
| 296 | void |
| 297 | userauth_finish(Authctxt *authctxt, int authenticated, char *method) |
| 298 | { |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 299 | char *methods; |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 300 | int partial = 0; |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 301 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 302 | if (!authctxt->valid && authenticated) |
| 303 | fatal("INTERNAL ERROR: authenticated invalid user %s", |
| 304 | authctxt->user); |
Damien Miller | b70b61f | 2000-09-16 16:25:12 +1100 | [diff] [blame] | 305 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 306 | /* Special handling for root */ |
Damien Miller | 556f931 | 2003-02-24 11:59:26 +1100 | [diff] [blame] | 307 | if (authenticated && authctxt->pw->pw_uid == 0 && |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 308 | !auth_root_allowed(method)) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 309 | authenticated = 0; |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 310 | #ifdef SSH_AUDIT_EVENTS |
| 311 | PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED)); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 312 | #endif |
| 313 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 314 | |
Damien Miller | 1f499fd | 2003-08-25 13:08:49 +1000 | [diff] [blame] | 315 | #ifdef USE_PAM |
Darren Tucker | 77fc29e | 2004-09-11 23:07:03 +1000 | [diff] [blame] | 316 | if (options.use_pam && authenticated) { |
| 317 | if (!PRIVSEP(do_pam_account())) { |
Darren Tucker | 77fc29e | 2004-09-11 23:07:03 +1000 | [diff] [blame] | 318 | /* if PAM returned a message, send it to the user */ |
| 319 | if (buffer_len(&loginmsg) > 0) { |
| 320 | buffer_append(&loginmsg, "\0", 1); |
| 321 | userauth_send_banner(buffer_ptr(&loginmsg)); |
Darren Tucker | c138667 | 2004-12-03 14:33:47 +1100 | [diff] [blame] | 322 | packet_write_wait(); |
Darren Tucker | 77fc29e | 2004-09-11 23:07:03 +1000 | [diff] [blame] | 323 | } |
Darren Tucker | c138667 | 2004-12-03 14:33:47 +1100 | [diff] [blame] | 324 | fatal("Access denied for user %s by PAM account " |
Damien Miller | b6f72f5 | 2005-07-17 17:26:43 +1000 | [diff] [blame] | 325 | "configuration", authctxt->user); |
Darren Tucker | 77fc29e | 2004-09-11 23:07:03 +1000 | [diff] [blame] | 326 | } |
| 327 | } |
Damien Miller | 1f499fd | 2003-08-25 13:08:49 +1000 | [diff] [blame] | 328 | #endif |
| 329 | |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 330 | #ifdef _UNICOS |
| 331 | if (authenticated && cray_access_denied(authctxt->user)) { |
| 332 | authenticated = 0; |
| 333 | fatal("Access denied for user %s.",authctxt->user); |
| 334 | } |
| 335 | #endif /* _UNICOS */ |
| 336 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 337 | /* Log before sending the reply */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 338 | auth_log(authctxt, authenticated, method, " ssh2"); |
| 339 | |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 340 | if (authctxt->postponed) |
| 341 | return; |
| 342 | |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 343 | if (authenticated && options.num_auth_methods != 0) { |
| 344 | if (!auth2_update_methods_lists(authctxt, method)) { |
| 345 | authenticated = 0; |
| 346 | partial = 1; |
| 347 | } |
| 348 | } |
| 349 | |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 350 | if (authenticated == 1) { |
| 351 | /* turn off userauth */ |
Damien Miller | 7d05339 | 2002-01-22 23:24:13 +1100 | [diff] [blame] | 352 | dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore); |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 353 | packet_start(SSH2_MSG_USERAUTH_SUCCESS); |
| 354 | packet_send(); |
| 355 | packet_write_wait(); |
| 356 | /* now we can break out */ |
| 357 | authctxt->success = 1; |
| 358 | } else { |
Damien Miller | 0b4d48b | 2008-07-05 09:44:53 +1000 | [diff] [blame] | 359 | |
| 360 | /* Allow initial try of "none" auth without failure penalty */ |
Damien Miller | 3fcdfd5 | 2011-05-05 14:04:11 +1000 | [diff] [blame] | 361 | if (!authctxt->server_caused_failure && |
| 362 | (authctxt->attempt > 1 || strcmp(method, "none") != 0)) |
Damien Miller | 0b4d48b | 2008-07-05 09:44:53 +1000 | [diff] [blame] | 363 | authctxt->failures++; |
| 364 | if (authctxt->failures >= options.max_authtries) { |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 365 | #ifdef SSH_AUDIT_EVENTS |
| 366 | PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES)); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 367 | #endif |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 368 | packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 369 | } |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 370 | methods = authmethods_get(authctxt); |
| 371 | debug3("%s: failure partial=%d next methods=\"%s\"", __func__, |
| 372 | partial, methods); |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 373 | packet_start(SSH2_MSG_USERAUTH_FAILURE); |
| 374 | packet_put_cstring(methods); |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 375 | packet_put_char(partial); |
Ben Lindstrom | cd4349f | 2001-06-09 00:23:17 +0000 | [diff] [blame] | 376 | packet_send(); |
| 377 | packet_write_wait(); |
| 378 | xfree(methods); |
| 379 | } |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 380 | } |
| 381 | |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 382 | /* |
| 383 | * Checks whether method is allowed by at least one AuthenticationMethods |
| 384 | * methods list. Returns 1 if allowed, or no methods lists configured. |
| 385 | * 0 otherwise. |
| 386 | */ |
| 387 | static int |
| 388 | method_allowed(Authctxt *authctxt, const char *method) |
| 389 | { |
| 390 | u_int i; |
| 391 | |
| 392 | /* |
| 393 | * NB. authctxt->num_auth_methods might be zero as a result of |
| 394 | * auth2_setup_methods_lists(), so check the configuration. |
| 395 | */ |
| 396 | if (options.num_auth_methods == 0) |
| 397 | return 1; |
| 398 | for (i = 0; i < authctxt->num_auth_methods; i++) { |
| 399 | if (list_starts_with(authctxt->auth_methods[i], method)) |
| 400 | return 1; |
| 401 | } |
| 402 | return 0; |
| 403 | } |
| 404 | |
Ben Lindstrom | 7907382 | 2001-07-04 03:42:30 +0000 | [diff] [blame] | 405 | static char * |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 406 | authmethods_get(Authctxt *authctxt) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 407 | { |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 408 | Buffer b; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 409 | char *list; |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 410 | u_int i; |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 411 | |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 412 | buffer_init(&b); |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 413 | for (i = 0; authmethods[i] != NULL; i++) { |
| 414 | if (strcmp(authmethods[i]->name, "none") == 0) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 415 | continue; |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 416 | if (authmethods[i]->enabled == NULL || |
| 417 | *(authmethods[i]->enabled) == 0) |
| 418 | continue; |
| 419 | if (!method_allowed(authctxt, authmethods[i]->name)) |
| 420 | continue; |
| 421 | if (buffer_len(&b) > 0) |
| 422 | buffer_append(&b, ",", 1); |
| 423 | buffer_append(&b, authmethods[i]->name, |
| 424 | strlen(authmethods[i]->name)); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 425 | } |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 426 | buffer_append(&b, "\0", 1); |
| 427 | list = xstrdup(buffer_ptr(&b)); |
| 428 | buffer_free(&b); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 429 | return list; |
| 430 | } |
| 431 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 432 | static Authmethod * |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 433 | authmethod_lookup(Authctxt *authctxt, const char *name) |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 434 | { |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 435 | int i; |
| 436 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 437 | if (name != NULL) |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 438 | for (i = 0; authmethods[i] != NULL; i++) |
| 439 | if (authmethods[i]->enabled != NULL && |
| 440 | *(authmethods[i]->enabled) != 0 && |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 441 | strcmp(name, authmethods[i]->name) == 0 && |
| 442 | method_allowed(authctxt, authmethods[i]->name)) |
Ben Lindstrom | 511bb24 | 2002-06-06 20:52:37 +0000 | [diff] [blame] | 443 | return authmethods[i]; |
| 444 | debug2("Unrecognized authentication method name: %s", |
| 445 | name ? name : "NULL"); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 446 | return NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 447 | } |
Darren Tucker | 4230a5d | 2008-07-02 22:56:09 +1000 | [diff] [blame] | 448 | |
Damien Miller | a6e3f01 | 2012-11-04 23:21:40 +1100 | [diff] [blame^] | 449 | /* |
| 450 | * Check a comma-separated list of methods for validity. Is need_enable is |
| 451 | * non-zero, then also require that the methods are enabled. |
| 452 | * Returns 0 on success or -1 if the methods list is invalid. |
| 453 | */ |
| 454 | int |
| 455 | auth2_methods_valid(const char *_methods, int need_enable) |
| 456 | { |
| 457 | char *methods, *omethods, *method; |
| 458 | u_int i, found; |
| 459 | int ret = -1; |
| 460 | |
| 461 | if (*_methods == '\0') { |
| 462 | error("empty authentication method list"); |
| 463 | return -1; |
| 464 | } |
| 465 | omethods = methods = xstrdup(_methods); |
| 466 | while ((method = strsep(&methods, ",")) != NULL) { |
| 467 | for (found = i = 0; !found && authmethods[i] != NULL; i++) { |
| 468 | if (strcmp(method, authmethods[i]->name) != 0) |
| 469 | continue; |
| 470 | if (need_enable) { |
| 471 | if (authmethods[i]->enabled == NULL || |
| 472 | *(authmethods[i]->enabled) == 0) { |
| 473 | error("Disabled method \"%s\" in " |
| 474 | "AuthenticationMethods list \"%s\"", |
| 475 | method, _methods); |
| 476 | goto out; |
| 477 | } |
| 478 | } |
| 479 | found = 1; |
| 480 | break; |
| 481 | } |
| 482 | if (!found) { |
| 483 | error("Unknown authentication method \"%s\" in list", |
| 484 | method); |
| 485 | goto out; |
| 486 | } |
| 487 | } |
| 488 | ret = 0; |
| 489 | out: |
| 490 | free(omethods); |
| 491 | return ret; |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * Prune the AuthenticationMethods supplied in the configuration, removing |
| 496 | * any methods lists that include disabled methods. Note that this might |
| 497 | * leave authctxt->num_auth_methods == 0, even when multiple required auth |
| 498 | * has been requested. For this reason, all tests for whether multiple is |
| 499 | * enabled should consult options.num_auth_methods directly. |
| 500 | */ |
| 501 | int |
| 502 | auth2_setup_methods_lists(Authctxt *authctxt) |
| 503 | { |
| 504 | u_int i; |
| 505 | |
| 506 | if (options.num_auth_methods == 0) |
| 507 | return 0; |
| 508 | debug3("%s: checking methods", __func__); |
| 509 | authctxt->auth_methods = xcalloc(options.num_auth_methods, |
| 510 | sizeof(*authctxt->auth_methods)); |
| 511 | authctxt->num_auth_methods = 0; |
| 512 | for (i = 0; i < options.num_auth_methods; i++) { |
| 513 | if (auth2_methods_valid(options.auth_methods[i], 1) != 0) { |
| 514 | logit("Authentication methods list \"%s\" contains " |
| 515 | "disabled method, skipping", |
| 516 | options.auth_methods[i]); |
| 517 | continue; |
| 518 | } |
| 519 | debug("authentication methods list %d: %s", |
| 520 | authctxt->num_auth_methods, options.auth_methods[i]); |
| 521 | authctxt->auth_methods[authctxt->num_auth_methods++] = |
| 522 | xstrdup(options.auth_methods[i]); |
| 523 | } |
| 524 | if (authctxt->num_auth_methods == 0) { |
| 525 | error("No AuthenticationMethods left after eliminating " |
| 526 | "disabled methods"); |
| 527 | return -1; |
| 528 | } |
| 529 | return 0; |
| 530 | } |
| 531 | |
| 532 | static int |
| 533 | list_starts_with(const char *methods, const char *method) |
| 534 | { |
| 535 | size_t l = strlen(method); |
| 536 | |
| 537 | if (strncmp(methods, method, l) != 0) |
| 538 | return 0; |
| 539 | if (methods[l] != ',' && methods[l] != '\0') |
| 540 | return 0; |
| 541 | return 1; |
| 542 | } |
| 543 | |
| 544 | /* |
| 545 | * Remove method from the start of a comma-separated list of methods. |
| 546 | * Returns 0 if the list of methods did not start with that method or 1 |
| 547 | * if it did. |
| 548 | */ |
| 549 | static int |
| 550 | remove_method(char **methods, const char *method) |
| 551 | { |
| 552 | char *omethods = *methods; |
| 553 | size_t l = strlen(method); |
| 554 | |
| 555 | if (!list_starts_with(omethods, method)) |
| 556 | return 0; |
| 557 | *methods = xstrdup(omethods + l + (omethods[l] == ',' ? 1 : 0)); |
| 558 | free(omethods); |
| 559 | return 1; |
| 560 | } |
| 561 | |
| 562 | /* |
| 563 | * Called after successful authentication. Will remove the successful method |
| 564 | * from the start of each list in which it occurs. If it was the last method |
| 565 | * in any list, then authentication is deemed successful. |
| 566 | * Returns 1 if the method completed any authentication list or 0 otherwise. |
| 567 | */ |
| 568 | int |
| 569 | auth2_update_methods_lists(Authctxt *authctxt, const char *method) |
| 570 | { |
| 571 | u_int i, found = 0; |
| 572 | |
| 573 | debug3("%s: updating methods list after \"%s\"", __func__, method); |
| 574 | for (i = 0; i < authctxt->num_auth_methods; i++) { |
| 575 | if (!remove_method(&(authctxt->auth_methods[i]), method)) |
| 576 | continue; |
| 577 | found = 1; |
| 578 | if (*authctxt->auth_methods[i] == '\0') { |
| 579 | debug2("authentication methods list %d complete", i); |
| 580 | return 1; |
| 581 | } |
| 582 | debug3("authentication methods list %d remaining: \"%s\"", |
| 583 | i, authctxt->auth_methods[i]); |
| 584 | } |
| 585 | /* This should not happen, but would be bad if it did */ |
| 586 | if (!found) |
| 587 | fatal("%s: method not in AuthenticationMethods", __func__); |
| 588 | return 0; |
| 589 | } |
| 590 | |
| 591 | |