Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 3 | * All rights reserved |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 4 | * |
| 5 | * As far as I am concerned, the code I have written for this software |
| 6 | * can be used freely for any purpose. Any derived versions of this |
| 7 | * software must be clearly marked as such, and if the derived work is |
| 8 | * incompatible with the protocol description in the RFC file, it must be |
| 9 | * called by a name other than "ssh" or "Secure Shell". |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include "includes.h" |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 13 | RCSID("$OpenBSD: auth1.c,v 1.4 2000/09/07 20:27:49 deraadt Exp $"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 14 | |
| 15 | #include "xmalloc.h" |
| 16 | #include "rsa.h" |
| 17 | #include "ssh.h" |
| 18 | #include "packet.h" |
| 19 | #include "buffer.h" |
| 20 | #include "cipher.h" |
| 21 | #include "mpaux.h" |
| 22 | #include "servconf.h" |
| 23 | #include "compat.h" |
| 24 | #include "auth.h" |
| 25 | #include "session.h" |
| 26 | |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 27 | #ifdef HAVE_OSF_SIA |
| 28 | # include <sia.h> |
| 29 | # include <siad.h> |
| 30 | #endif |
| 31 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 32 | /* import */ |
| 33 | extern ServerOptions options; |
| 34 | extern char *forced_command; |
Damien Miller | fe668e4 | 2000-07-08 10:44:13 +1000 | [diff] [blame] | 35 | #ifdef HAVE_OSF_SIA |
| 36 | extern int saved_argc; |
| 37 | extern char **saved_argv; |
| 38 | #endif /* HAVE_OSF_SIA */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 39 | |
| 40 | /* |
| 41 | * convert ssh auth msg type into description |
| 42 | */ |
| 43 | char * |
| 44 | get_authname(int type) |
| 45 | { |
| 46 | static char buf[1024]; |
| 47 | switch (type) { |
| 48 | case SSH_CMSG_AUTH_PASSWORD: |
| 49 | return "password"; |
| 50 | case SSH_CMSG_AUTH_RSA: |
| 51 | return "rsa"; |
| 52 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 53 | return "rhosts-rsa"; |
| 54 | case SSH_CMSG_AUTH_RHOSTS: |
| 55 | return "rhosts"; |
| 56 | #ifdef KRB4 |
| 57 | case SSH_CMSG_AUTH_KERBEROS: |
| 58 | return "kerberos"; |
| 59 | #endif |
| 60 | #ifdef SKEY |
| 61 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 62 | return "s/key"; |
| 63 | #endif |
| 64 | } |
| 65 | snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); |
| 66 | return buf; |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * The user does not exist or access is denied, |
| 71 | * but fake indication that authentication is needed. |
| 72 | */ |
| 73 | void |
| 74 | do_fake_authloop1(char *user) |
| 75 | { |
| 76 | int attempt = 0; |
| 77 | |
| 78 | log("Faking authloop for illegal user %.200s from %.200s port %d", |
| 79 | user, |
| 80 | get_remote_ipaddr(), |
| 81 | get_remote_port()); |
| 82 | |
| 83 | #ifdef WITH_AIXAUTHENTICATE |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 84 | loginfailed(user,get_canonical_hostname(),"ssh"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 85 | #endif /* WITH_AIXAUTHENTICATE */ |
| 86 | |
| 87 | /* Indicate that authentication is needed. */ |
| 88 | packet_start(SSH_SMSG_FAILURE); |
| 89 | packet_send(); |
| 90 | packet_write_wait(); |
| 91 | |
| 92 | /* |
| 93 | * Keep reading packets, and always respond with a failure. This is |
| 94 | * to avoid disclosing whether such a user really exists. |
| 95 | */ |
| 96 | for (attempt = 1;; attempt++) { |
| 97 | /* Read a packet. This will not return if the client disconnects. */ |
| 98 | int plen; |
| 99 | #ifndef SKEY |
| 100 | (void)packet_read(&plen); |
| 101 | #else /* SKEY */ |
| 102 | int type = packet_read(&plen); |
| 103 | unsigned int dlen; |
| 104 | char *password, *skeyinfo; |
| 105 | password = NULL; |
| 106 | /* Try to send a fake s/key challenge. */ |
| 107 | if (options.skey_authentication == 1 && |
| 108 | (skeyinfo = skey_fake_keyinfo(user)) != NULL) { |
| 109 | if (type == SSH_CMSG_AUTH_TIS) { |
| 110 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
| 111 | packet_put_string(skeyinfo, strlen(skeyinfo)); |
| 112 | packet_send(); |
| 113 | packet_write_wait(); |
| 114 | continue; |
| 115 | } else if (type == SSH_CMSG_AUTH_PASSWORD && |
| 116 | options.password_authentication && |
| 117 | (password = packet_get_string(&dlen)) != NULL && |
| 118 | dlen == 5 && |
| 119 | strncasecmp(password, "s/key", 5) == 0 ) { |
| 120 | packet_send_debug(skeyinfo); |
| 121 | } |
| 122 | } |
| 123 | if (password != NULL) |
| 124 | xfree(password); |
| 125 | #endif |
| 126 | if (attempt > AUTH_FAIL_MAX) |
| 127 | packet_disconnect(AUTH_FAIL_MSG, user); |
| 128 | |
| 129 | /* |
| 130 | * Send failure. This should be indistinguishable from a |
| 131 | * failed authentication. |
| 132 | */ |
| 133 | packet_start(SSH_SMSG_FAILURE); |
| 134 | packet_send(); |
| 135 | packet_write_wait(); |
| 136 | } |
| 137 | /* NOTREACHED */ |
| 138 | abort(); |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * read packets and try to authenticate local user *pw. |
| 143 | * return if authentication is successfull |
| 144 | */ |
| 145 | void |
| 146 | do_authloop(struct passwd * pw) |
| 147 | { |
| 148 | int attempt = 0; |
| 149 | unsigned int bits; |
| 150 | RSA *client_host_key; |
| 151 | BIGNUM *n; |
| 152 | char *client_user = NULL, *password = NULL; |
| 153 | char user[1024]; |
| 154 | unsigned int dlen; |
| 155 | int plen, nlen, elen; |
| 156 | unsigned int ulen; |
| 157 | int type = 0; |
| 158 | void (*authlog) (const char *fmt,...) = verbose; |
| 159 | |
| 160 | /* Indicate that authentication is needed. */ |
| 161 | packet_start(SSH_SMSG_FAILURE); |
| 162 | packet_send(); |
| 163 | packet_write_wait(); |
| 164 | |
| 165 | for (attempt = 1;; attempt++) { |
| 166 | int authenticated = 0; |
| 167 | strlcpy(user, "", sizeof user); |
| 168 | |
| 169 | /* Get a packet from the client. */ |
| 170 | type = packet_read(&plen); |
| 171 | |
| 172 | /* Process the packet. */ |
| 173 | switch (type) { |
| 174 | #ifdef AFS |
| 175 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
| 176 | if (!options.kerberos_tgt_passing) { |
| 177 | /* packet_get_all(); */ |
| 178 | verbose("Kerberos tgt passing disabled."); |
| 179 | break; |
| 180 | } else { |
| 181 | /* Accept Kerberos tgt. */ |
| 182 | char *tgt = packet_get_string(&dlen); |
| 183 | packet_integrity_check(plen, 4 + dlen, type); |
| 184 | if (!auth_kerberos_tgt(pw, tgt)) |
| 185 | verbose("Kerberos tgt REFUSED for %s", pw->pw_name); |
| 186 | xfree(tgt); |
| 187 | } |
| 188 | continue; |
| 189 | |
| 190 | case SSH_CMSG_HAVE_AFS_TOKEN: |
| 191 | if (!options.afs_token_passing || !k_hasafs()) { |
| 192 | /* packet_get_all(); */ |
| 193 | verbose("AFS token passing disabled."); |
| 194 | break; |
| 195 | } else { |
| 196 | /* Accept AFS token. */ |
| 197 | char *token_string = packet_get_string(&dlen); |
| 198 | packet_integrity_check(plen, 4 + dlen, type); |
| 199 | if (!auth_afs_token(pw, token_string)) |
| 200 | verbose("AFS token REFUSED for %s", pw->pw_name); |
| 201 | xfree(token_string); |
| 202 | } |
| 203 | continue; |
| 204 | #endif /* AFS */ |
| 205 | #ifdef KRB4 |
| 206 | case SSH_CMSG_AUTH_KERBEROS: |
| 207 | if (!options.kerberos_authentication) { |
| 208 | /* packet_get_all(); */ |
| 209 | verbose("Kerberos authentication disabled."); |
| 210 | break; |
| 211 | } else { |
| 212 | /* Try Kerberos v4 authentication. */ |
| 213 | KTEXT_ST auth; |
| 214 | char *tkt_user = NULL; |
| 215 | char *kdata = packet_get_string((unsigned int *) &auth.length); |
| 216 | packet_integrity_check(plen, 4 + auth.length, type); |
| 217 | |
| 218 | if (auth.length < MAX_KTXT_LEN) |
| 219 | memcpy(auth.dat, kdata, auth.length); |
| 220 | xfree(kdata); |
| 221 | |
| 222 | authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); |
| 223 | |
| 224 | if (authenticated) { |
| 225 | snprintf(user, sizeof user, " tktuser %s", tkt_user); |
| 226 | xfree(tkt_user); |
| 227 | } |
| 228 | } |
| 229 | break; |
| 230 | #endif /* KRB4 */ |
| 231 | |
| 232 | case SSH_CMSG_AUTH_RHOSTS: |
| 233 | if (!options.rhosts_authentication) { |
| 234 | verbose("Rhosts authentication disabled."); |
| 235 | break; |
| 236 | } |
| 237 | /* |
| 238 | * Get client user name. Note that we just have to |
| 239 | * trust the client; this is one reason why rhosts |
| 240 | * authentication is insecure. (Another is |
| 241 | * IP-spoofing on a local network.) |
| 242 | */ |
| 243 | client_user = packet_get_string(&ulen); |
| 244 | packet_integrity_check(plen, 4 + ulen, type); |
| 245 | |
| 246 | /* Try to authenticate using /etc/hosts.equiv and |
| 247 | .rhosts. */ |
| 248 | authenticated = auth_rhosts(pw, client_user); |
| 249 | |
| 250 | snprintf(user, sizeof user, " ruser %s", client_user); |
| 251 | break; |
| 252 | |
| 253 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 254 | if (!options.rhosts_rsa_authentication) { |
| 255 | verbose("Rhosts with RSA authentication disabled."); |
| 256 | break; |
| 257 | } |
| 258 | /* |
| 259 | * Get client user name. Note that we just have to |
| 260 | * trust the client; root on the client machine can |
| 261 | * claim to be any user. |
| 262 | */ |
| 263 | client_user = packet_get_string(&ulen); |
| 264 | |
| 265 | /* Get the client host key. */ |
| 266 | client_host_key = RSA_new(); |
| 267 | if (client_host_key == NULL) |
| 268 | fatal("RSA_new failed"); |
| 269 | client_host_key->e = BN_new(); |
| 270 | client_host_key->n = BN_new(); |
| 271 | if (client_host_key->e == NULL || client_host_key->n == NULL) |
| 272 | fatal("BN_new failed"); |
| 273 | bits = packet_get_int(); |
| 274 | packet_get_bignum(client_host_key->e, &elen); |
| 275 | packet_get_bignum(client_host_key->n, &nlen); |
| 276 | |
| 277 | if (bits != BN_num_bits(client_host_key->n)) |
Damien Miller | bd483e7 | 2000-04-30 10:00:53 +1000 | [diff] [blame] | 278 | log("Warning: keysize mismatch for client_host_key: " |
| 279 | "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 280 | packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); |
| 281 | |
| 282 | authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); |
| 283 | RSA_free(client_host_key); |
| 284 | |
| 285 | snprintf(user, sizeof user, " ruser %s", client_user); |
| 286 | break; |
| 287 | |
| 288 | case SSH_CMSG_AUTH_RSA: |
| 289 | if (!options.rsa_authentication) { |
| 290 | verbose("RSA authentication disabled."); |
| 291 | break; |
| 292 | } |
| 293 | /* RSA authentication requested. */ |
| 294 | n = BN_new(); |
| 295 | packet_get_bignum(n, &nlen); |
| 296 | packet_integrity_check(plen, nlen, type); |
| 297 | authenticated = auth_rsa(pw, n); |
| 298 | BN_clear_free(n); |
| 299 | break; |
| 300 | |
| 301 | case SSH_CMSG_AUTH_PASSWORD: |
| 302 | if (!options.password_authentication) { |
| 303 | verbose("Password authentication disabled."); |
| 304 | break; |
| 305 | } |
| 306 | /* |
| 307 | * Read user password. It is in plain text, but was |
| 308 | * transmitted over the encrypted channel so it is |
| 309 | * not visible to an outside observer. |
| 310 | */ |
| 311 | password = packet_get_string(&dlen); |
| 312 | packet_integrity_check(plen, 4 + dlen, type); |
| 313 | |
| 314 | #ifdef USE_PAM |
| 315 | /* Do PAM auth with password */ |
| 316 | authenticated = auth_pam_password(pw, password); |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 317 | #elif defined(HAVE_OSF_SIA) |
| 318 | /* Do SIA auth with password */ |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 319 | if (sia_validate_user(NULL, saved_argc, saved_argv, |
| 320 | get_canonical_hostname(), pw->pw_name, NULL, 0, |
| 321 | NULL, password) == SIASUCCESS) { |
| 322 | authenticated = 1; |
| 323 | } |
| 324 | #else /* !USE_PAM && !HAVE_OSF_SIA */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 325 | /* Try authentication with the password. */ |
| 326 | authenticated = auth_password(pw, password); |
| 327 | #endif /* USE_PAM */ |
| 328 | |
| 329 | memset(password, 0, strlen(password)); |
| 330 | xfree(password); |
| 331 | break; |
| 332 | |
| 333 | #ifdef SKEY |
| 334 | case SSH_CMSG_AUTH_TIS: |
| 335 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
| 336 | if (options.skey_authentication == 1) { |
| 337 | char *skeyinfo = skey_keyinfo(pw->pw_name); |
| 338 | if (skeyinfo == NULL) { |
| 339 | debug("generating fake skeyinfo for %.100s.", pw->pw_name); |
| 340 | skeyinfo = skey_fake_keyinfo(pw->pw_name); |
| 341 | } |
| 342 | if (skeyinfo != NULL) { |
| 343 | /* we send our s/key- in tis-challenge messages */ |
| 344 | debug("sending challenge '%s'", skeyinfo); |
| 345 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
| 346 | packet_put_string(skeyinfo, strlen(skeyinfo)); |
| 347 | packet_send(); |
| 348 | packet_write_wait(); |
| 349 | continue; |
| 350 | } |
| 351 | } |
| 352 | break; |
| 353 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 354 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); |
| 355 | if (options.skey_authentication == 1) { |
| 356 | char *response = packet_get_string(&dlen); |
| 357 | debug("skey response == '%s'", response); |
| 358 | packet_integrity_check(plen, 4 + dlen, type); |
| 359 | authenticated = (skey_haskey(pw->pw_name) == 0 && |
| 360 | skey_passcheck(pw->pw_name, response) != -1); |
| 361 | xfree(response); |
| 362 | } |
| 363 | break; |
| 364 | #else |
| 365 | case SSH_CMSG_AUTH_TIS: |
| 366 | /* TIS Authentication is unsupported */ |
| 367 | log("TIS authentication unsupported."); |
| 368 | break; |
| 369 | #endif |
| 370 | |
| 371 | default: |
| 372 | /* |
| 373 | * Any unknown messages will be ignored (and failure |
| 374 | * returned) during authentication. |
| 375 | */ |
| 376 | log("Unknown message during authentication: type %d", type); |
| 377 | break; |
| 378 | } |
| 379 | |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 380 | #ifdef HAVE_CYGWIN |
Damien Miller | b70b61f | 2000-09-16 16:25:12 +1100 | [diff] [blame^] | 381 | if (authenticated && |
| 382 | !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) { |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 383 | packet_disconnect("Authentication rejected for uid %d.", |
| 384 | (int) pw->pw_uid); |
| 385 | authenticated = 0; |
| 386 | } |
| 387 | #endif |
| 388 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 389 | /* |
| 390 | * Check if the user is logging in as root and root logins |
| 391 | * are disallowed. |
| 392 | * Note that root login is allowed for forced commands. |
| 393 | */ |
| 394 | if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) { |
| 395 | if (forced_command) { |
| 396 | log("Root login accepted for forced command."); |
| 397 | } else { |
| 398 | authenticated = 0; |
| 399 | log("ROOT LOGIN REFUSED FROM %.200s", |
| 400 | get_canonical_hostname()); |
| 401 | } |
| 402 | } |
| 403 | |
| 404 | /* Raise logging level */ |
| 405 | if (authenticated || |
| 406 | attempt == AUTH_FAIL_LOG || |
| 407 | type == SSH_CMSG_AUTH_PASSWORD) |
| 408 | authlog = log; |
| 409 | |
| 410 | authlog("%s %s for %.200s from %.200s port %d%s", |
| 411 | authenticated ? "Accepted" : "Failed", |
| 412 | get_authname(type), |
| 413 | pw->pw_uid == 0 ? "ROOT" : pw->pw_name, |
| 414 | get_remote_ipaddr(), |
| 415 | get_remote_port(), |
| 416 | user); |
| 417 | |
| 418 | #ifdef USE_PAM |
| 419 | if (authenticated) { |
| 420 | if (!do_pam_account(pw->pw_name, client_user)) { |
| 421 | if (client_user != NULL) { |
| 422 | xfree(client_user); |
| 423 | client_user = NULL; |
| 424 | } |
| 425 | do_fake_authloop1(pw->pw_name); |
| 426 | } |
| 427 | return; |
| 428 | } |
| 429 | #else /* USE_PAM */ |
| 430 | if (authenticated) { |
| 431 | return; |
| 432 | } |
| 433 | #endif /* USE_PAM */ |
| 434 | |
| 435 | if (client_user != NULL) { |
| 436 | xfree(client_user); |
| 437 | client_user = NULL; |
| 438 | } |
| 439 | |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 440 | if (attempt > AUTH_FAIL_MAX) { |
| 441 | #ifdef WITH_AIXAUTHENTICATE |
| 442 | loginfailed(pw->pw_name,get_canonical_hostname(),"ssh"); |
| 443 | #endif /* WITH_AIXAUTHENTICATE */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 444 | packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 445 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 446 | |
| 447 | /* Send a message indicating that the authentication attempt failed. */ |
| 448 | packet_start(SSH_SMSG_FAILURE); |
| 449 | packet_send(); |
| 450 | packet_write_wait(); |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | /* |
| 455 | * Performs authentication of an incoming connection. Session key has already |
| 456 | * been exchanged and encryption is enabled. |
| 457 | */ |
| 458 | void |
| 459 | do_authentication() |
| 460 | { |
| 461 | struct passwd *pw, pwcopy; |
| 462 | int plen; |
| 463 | unsigned int ulen; |
| 464 | char *user; |
| 465 | #ifdef WITH_AIXAUTHENTICATE |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 466 | extern char *aixloginmsg; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 467 | #endif /* WITH_AIXAUTHENTICATE */ |
| 468 | |
| 469 | /* Get the name of the user that we wish to log in as. */ |
| 470 | packet_read_expect(&plen, SSH_CMSG_USER); |
| 471 | |
| 472 | /* Get the user name. */ |
| 473 | user = packet_get_string(&ulen); |
| 474 | packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); |
| 475 | |
| 476 | setproctitle("%s", user); |
| 477 | |
| 478 | #ifdef AFS |
| 479 | /* If machine has AFS, set process authentication group. */ |
| 480 | if (k_hasafs()) { |
| 481 | k_setpag(); |
| 482 | k_unlog(); |
| 483 | } |
| 484 | #endif /* AFS */ |
| 485 | |
| 486 | /* Verify that the user is a valid user. */ |
| 487 | pw = getpwnam(user); |
| 488 | if (!pw || !allowed_user(pw)) |
| 489 | do_fake_authloop1(user); |
| 490 | xfree(user); |
| 491 | |
| 492 | /* Take a copy of the returned structure. */ |
| 493 | memset(&pwcopy, 0, sizeof(pwcopy)); |
| 494 | pwcopy.pw_name = xstrdup(pw->pw_name); |
| 495 | pwcopy.pw_passwd = xstrdup(pw->pw_passwd); |
| 496 | pwcopy.pw_uid = pw->pw_uid; |
| 497 | pwcopy.pw_gid = pw->pw_gid; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 498 | #ifdef HAVE_PW_CLASS_IN_PASSWD |
| 499 | pwcopy.pw_class = xstrdup(pw->pw_class); |
| 500 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 501 | pwcopy.pw_dir = xstrdup(pw->pw_dir); |
| 502 | pwcopy.pw_shell = xstrdup(pw->pw_shell); |
| 503 | pw = &pwcopy; |
| 504 | |
| 505 | #ifdef USE_PAM |
| 506 | start_pam(pw); |
| 507 | #endif |
| 508 | |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 509 | #ifndef HAVE_CYGWIN |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 510 | /* |
| 511 | * If we are not running as root, the user must have the same uid as |
| 512 | * the server. |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 513 | * Rule not valid on Windows systems. |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 514 | */ |
| 515 | if (getuid() != 0 && pw->pw_uid != getuid()) |
| 516 | packet_disconnect("Cannot change user when server not running as root."); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 517 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 518 | |
| 519 | debug("Attempting authentication for %.100s.", pw->pw_name); |
| 520 | |
| 521 | /* If the user has no password, accept authentication immediately. */ |
| 522 | if (options.password_authentication && |
| 523 | #ifdef KRB4 |
| 524 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && |
| 525 | #endif /* KRB4 */ |
| 526 | #ifdef USE_PAM |
| 527 | auth_pam_password(pw, "")) { |
Damien Miller | d8cfda6 | 2000-07-01 12:56:09 +1000 | [diff] [blame] | 528 | #elif defined(HAVE_OSF_SIA) |
| 529 | (sia_validate_user(NULL, saved_argc, saved_argv, |
| 530 | get_canonical_hostname(), pw->pw_name, NULL, 0, NULL, |
| 531 | "") == SIASUCCESS)) { |
| 532 | #else /* !HAVE_OSF_SIA && !USE_PAM */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 533 | auth_password(pw, "")) { |
| 534 | #endif /* USE_PAM */ |
| 535 | /* Authentication with empty password succeeded. */ |
| 536 | log("Login for user %s from %.100s, accepted without authentication.", |
| 537 | pw->pw_name, get_remote_ipaddr()); |
| 538 | } else { |
| 539 | /* Loop until the user has been authenticated or the |
| 540 | connection is closed, do_authloop() returns only if |
| 541 | authentication is successfull */ |
| 542 | do_authloop(pw); |
| 543 | } |
| 544 | |
| 545 | /* The user has been authenticated and accepted. */ |
| 546 | #ifdef WITH_AIXAUTHENTICATE |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 547 | /* We don't have a pty yet, so just label the line as "ssh" */ |
| 548 | if (loginsuccess(user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0) |
| 549 | aixloginmsg = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 550 | #endif /* WITH_AIXAUTHENTICATE */ |
| 551 | packet_start(SSH_SMSG_SUCCESS); |
| 552 | packet_send(); |
| 553 | packet_write_wait(); |
| 554 | |
| 555 | /* Perform session preparation. */ |
| 556 | do_authenticated(pw); |
| 557 | } |