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 |
| 4 | */ |
| 5 | |
| 6 | #include "includes.h" |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 7 | RCSID("$OpenBSD: auth1.c,v 1.3 2000/08/20 18:42:40 millert Exp $"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 8 | |
| 9 | #include "xmalloc.h" |
| 10 | #include "rsa.h" |
| 11 | #include "ssh.h" |
| 12 | #include "packet.h" |
| 13 | #include "buffer.h" |
| 14 | #include "cipher.h" |
| 15 | #include "mpaux.h" |
| 16 | #include "servconf.h" |
| 17 | #include "compat.h" |
| 18 | #include "auth.h" |
| 19 | #include "session.h" |
| 20 | |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 21 | #ifdef HAVE_OSF_SIA |
| 22 | # include <sia.h> |
| 23 | # include <siad.h> |
| 24 | #endif |
| 25 | |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 26 | #ifdef HAVE_CYGWIN |
| 27 | #include <windows.h> |
| 28 | #define is_winnt (GetVersion() < 0x80000000) |
| 29 | #endif |
| 30 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 31 | /* import */ |
| 32 | extern ServerOptions options; |
| 33 | extern char *forced_command; |
Damien Miller | fe668e4 | 2000-07-08 10:44:13 +1000 | [diff] [blame] | 34 | #ifdef HAVE_OSF_SIA |
| 35 | extern int saved_argc; |
| 36 | extern char **saved_argv; |
| 37 | #endif /* HAVE_OSF_SIA */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 38 | |
| 39 | /* |
| 40 | * convert ssh auth msg type into description |
| 41 | */ |
| 42 | char * |
| 43 | get_authname(int type) |
| 44 | { |
| 45 | static char buf[1024]; |
| 46 | switch (type) { |
| 47 | case SSH_CMSG_AUTH_PASSWORD: |
| 48 | return "password"; |
| 49 | case SSH_CMSG_AUTH_RSA: |
| 50 | return "rsa"; |
| 51 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 52 | return "rhosts-rsa"; |
| 53 | case SSH_CMSG_AUTH_RHOSTS: |
| 54 | return "rhosts"; |
| 55 | #ifdef KRB4 |
| 56 | case SSH_CMSG_AUTH_KERBEROS: |
| 57 | return "kerberos"; |
| 58 | #endif |
| 59 | #ifdef SKEY |
| 60 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 61 | return "s/key"; |
| 62 | #endif |
| 63 | } |
| 64 | snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); |
| 65 | return buf; |
| 66 | } |
| 67 | |
| 68 | /* |
| 69 | * The user does not exist or access is denied, |
| 70 | * but fake indication that authentication is needed. |
| 71 | */ |
| 72 | void |
| 73 | do_fake_authloop1(char *user) |
| 74 | { |
| 75 | int attempt = 0; |
| 76 | |
| 77 | log("Faking authloop for illegal user %.200s from %.200s port %d", |
| 78 | user, |
| 79 | get_remote_ipaddr(), |
| 80 | get_remote_port()); |
| 81 | |
| 82 | #ifdef WITH_AIXAUTHENTICATE |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 83 | loginfailed(user,get_canonical_hostname(),"ssh"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 84 | #endif /* WITH_AIXAUTHENTICATE */ |
| 85 | |
| 86 | /* Indicate that authentication is needed. */ |
| 87 | packet_start(SSH_SMSG_FAILURE); |
| 88 | packet_send(); |
| 89 | packet_write_wait(); |
| 90 | |
| 91 | /* |
| 92 | * Keep reading packets, and always respond with a failure. This is |
| 93 | * to avoid disclosing whether such a user really exists. |
| 94 | */ |
| 95 | for (attempt = 1;; attempt++) { |
| 96 | /* Read a packet. This will not return if the client disconnects. */ |
| 97 | int plen; |
| 98 | #ifndef SKEY |
| 99 | (void)packet_read(&plen); |
| 100 | #else /* SKEY */ |
| 101 | int type = packet_read(&plen); |
| 102 | unsigned int dlen; |
| 103 | char *password, *skeyinfo; |
| 104 | password = NULL; |
| 105 | /* Try to send a fake s/key challenge. */ |
| 106 | if (options.skey_authentication == 1 && |
| 107 | (skeyinfo = skey_fake_keyinfo(user)) != NULL) { |
| 108 | if (type == SSH_CMSG_AUTH_TIS) { |
| 109 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
| 110 | packet_put_string(skeyinfo, strlen(skeyinfo)); |
| 111 | packet_send(); |
| 112 | packet_write_wait(); |
| 113 | continue; |
| 114 | } else if (type == SSH_CMSG_AUTH_PASSWORD && |
| 115 | options.password_authentication && |
| 116 | (password = packet_get_string(&dlen)) != NULL && |
| 117 | dlen == 5 && |
| 118 | strncasecmp(password, "s/key", 5) == 0 ) { |
| 119 | packet_send_debug(skeyinfo); |
| 120 | } |
| 121 | } |
| 122 | if (password != NULL) |
| 123 | xfree(password); |
| 124 | #endif |
| 125 | if (attempt > AUTH_FAIL_MAX) |
| 126 | packet_disconnect(AUTH_FAIL_MSG, user); |
| 127 | |
| 128 | /* |
| 129 | * Send failure. This should be indistinguishable from a |
| 130 | * failed authentication. |
| 131 | */ |
| 132 | packet_start(SSH_SMSG_FAILURE); |
| 133 | packet_send(); |
| 134 | packet_write_wait(); |
| 135 | } |
| 136 | /* NOTREACHED */ |
| 137 | abort(); |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * read packets and try to authenticate local user *pw. |
| 142 | * return if authentication is successfull |
| 143 | */ |
| 144 | void |
| 145 | do_authloop(struct passwd * pw) |
| 146 | { |
| 147 | int attempt = 0; |
| 148 | unsigned int bits; |
| 149 | RSA *client_host_key; |
| 150 | BIGNUM *n; |
| 151 | char *client_user = NULL, *password = NULL; |
| 152 | char user[1024]; |
| 153 | unsigned int dlen; |
| 154 | int plen, nlen, elen; |
| 155 | unsigned int ulen; |
| 156 | int type = 0; |
| 157 | void (*authlog) (const char *fmt,...) = verbose; |
| 158 | |
| 159 | /* Indicate that authentication is needed. */ |
| 160 | packet_start(SSH_SMSG_FAILURE); |
| 161 | packet_send(); |
| 162 | packet_write_wait(); |
| 163 | |
| 164 | for (attempt = 1;; attempt++) { |
| 165 | int authenticated = 0; |
| 166 | strlcpy(user, "", sizeof user); |
| 167 | |
| 168 | /* Get a packet from the client. */ |
| 169 | type = packet_read(&plen); |
| 170 | |
| 171 | /* Process the packet. */ |
| 172 | switch (type) { |
| 173 | #ifdef AFS |
| 174 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
| 175 | if (!options.kerberos_tgt_passing) { |
| 176 | /* packet_get_all(); */ |
| 177 | verbose("Kerberos tgt passing disabled."); |
| 178 | break; |
| 179 | } else { |
| 180 | /* Accept Kerberos tgt. */ |
| 181 | char *tgt = packet_get_string(&dlen); |
| 182 | packet_integrity_check(plen, 4 + dlen, type); |
| 183 | if (!auth_kerberos_tgt(pw, tgt)) |
| 184 | verbose("Kerberos tgt REFUSED for %s", pw->pw_name); |
| 185 | xfree(tgt); |
| 186 | } |
| 187 | continue; |
| 188 | |
| 189 | case SSH_CMSG_HAVE_AFS_TOKEN: |
| 190 | if (!options.afs_token_passing || !k_hasafs()) { |
| 191 | /* packet_get_all(); */ |
| 192 | verbose("AFS token passing disabled."); |
| 193 | break; |
| 194 | } else { |
| 195 | /* Accept AFS token. */ |
| 196 | char *token_string = packet_get_string(&dlen); |
| 197 | packet_integrity_check(plen, 4 + dlen, type); |
| 198 | if (!auth_afs_token(pw, token_string)) |
| 199 | verbose("AFS token REFUSED for %s", pw->pw_name); |
| 200 | xfree(token_string); |
| 201 | } |
| 202 | continue; |
| 203 | #endif /* AFS */ |
| 204 | #ifdef KRB4 |
| 205 | case SSH_CMSG_AUTH_KERBEROS: |
| 206 | if (!options.kerberos_authentication) { |
| 207 | /* packet_get_all(); */ |
| 208 | verbose("Kerberos authentication disabled."); |
| 209 | break; |
| 210 | } else { |
| 211 | /* Try Kerberos v4 authentication. */ |
| 212 | KTEXT_ST auth; |
| 213 | char *tkt_user = NULL; |
| 214 | char *kdata = packet_get_string((unsigned int *) &auth.length); |
| 215 | packet_integrity_check(plen, 4 + auth.length, type); |
| 216 | |
| 217 | if (auth.length < MAX_KTXT_LEN) |
| 218 | memcpy(auth.dat, kdata, auth.length); |
| 219 | xfree(kdata); |
| 220 | |
| 221 | authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); |
| 222 | |
| 223 | if (authenticated) { |
| 224 | snprintf(user, sizeof user, " tktuser %s", tkt_user); |
| 225 | xfree(tkt_user); |
| 226 | } |
| 227 | } |
| 228 | break; |
| 229 | #endif /* KRB4 */ |
| 230 | |
| 231 | case SSH_CMSG_AUTH_RHOSTS: |
| 232 | if (!options.rhosts_authentication) { |
| 233 | verbose("Rhosts authentication disabled."); |
| 234 | break; |
| 235 | } |
| 236 | /* |
| 237 | * Get client user name. Note that we just have to |
| 238 | * trust the client; this is one reason why rhosts |
| 239 | * authentication is insecure. (Another is |
| 240 | * IP-spoofing on a local network.) |
| 241 | */ |
| 242 | client_user = packet_get_string(&ulen); |
| 243 | packet_integrity_check(plen, 4 + ulen, type); |
| 244 | |
| 245 | /* Try to authenticate using /etc/hosts.equiv and |
| 246 | .rhosts. */ |
| 247 | authenticated = auth_rhosts(pw, client_user); |
| 248 | |
| 249 | snprintf(user, sizeof user, " ruser %s", client_user); |
| 250 | break; |
| 251 | |
| 252 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
| 253 | if (!options.rhosts_rsa_authentication) { |
| 254 | verbose("Rhosts with RSA authentication disabled."); |
| 255 | break; |
| 256 | } |
| 257 | /* |
| 258 | * Get client user name. Note that we just have to |
| 259 | * trust the client; root on the client machine can |
| 260 | * claim to be any user. |
| 261 | */ |
| 262 | client_user = packet_get_string(&ulen); |
| 263 | |
| 264 | /* Get the client host key. */ |
| 265 | client_host_key = RSA_new(); |
| 266 | if (client_host_key == NULL) |
| 267 | fatal("RSA_new failed"); |
| 268 | client_host_key->e = BN_new(); |
| 269 | client_host_key->n = BN_new(); |
| 270 | if (client_host_key->e == NULL || client_host_key->n == NULL) |
| 271 | fatal("BN_new failed"); |
| 272 | bits = packet_get_int(); |
| 273 | packet_get_bignum(client_host_key->e, &elen); |
| 274 | packet_get_bignum(client_host_key->n, &nlen); |
| 275 | |
| 276 | if (bits != BN_num_bits(client_host_key->n)) |
Damien Miller | bd483e7 | 2000-04-30 10:00:53 +1000 | [diff] [blame] | 277 | log("Warning: keysize mismatch for client_host_key: " |
| 278 | "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 279 | packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); |
| 280 | |
| 281 | authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); |
| 282 | RSA_free(client_host_key); |
| 283 | |
| 284 | snprintf(user, sizeof user, " ruser %s", client_user); |
| 285 | break; |
| 286 | |
| 287 | case SSH_CMSG_AUTH_RSA: |
| 288 | if (!options.rsa_authentication) { |
| 289 | verbose("RSA authentication disabled."); |
| 290 | break; |
| 291 | } |
| 292 | /* RSA authentication requested. */ |
| 293 | n = BN_new(); |
| 294 | packet_get_bignum(n, &nlen); |
| 295 | packet_integrity_check(plen, nlen, type); |
| 296 | authenticated = auth_rsa(pw, n); |
| 297 | BN_clear_free(n); |
| 298 | break; |
| 299 | |
| 300 | case SSH_CMSG_AUTH_PASSWORD: |
| 301 | if (!options.password_authentication) { |
| 302 | verbose("Password authentication disabled."); |
| 303 | break; |
| 304 | } |
| 305 | /* |
| 306 | * Read user password. It is in plain text, but was |
| 307 | * transmitted over the encrypted channel so it is |
| 308 | * not visible to an outside observer. |
| 309 | */ |
| 310 | password = packet_get_string(&dlen); |
| 311 | packet_integrity_check(plen, 4 + dlen, type); |
| 312 | |
| 313 | #ifdef USE_PAM |
| 314 | /* Do PAM auth with password */ |
| 315 | authenticated = auth_pam_password(pw, password); |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 316 | #elif defined(HAVE_OSF_SIA) |
| 317 | /* Do SIA auth with password */ |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 318 | if (sia_validate_user(NULL, saved_argc, saved_argv, |
| 319 | get_canonical_hostname(), pw->pw_name, NULL, 0, |
| 320 | NULL, password) == SIASUCCESS) { |
| 321 | authenticated = 1; |
| 322 | } |
| 323 | #else /* !USE_PAM && !HAVE_OSF_SIA */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 324 | /* Try authentication with the password. */ |
| 325 | authenticated = auth_password(pw, password); |
| 326 | #endif /* USE_PAM */ |
| 327 | |
| 328 | memset(password, 0, strlen(password)); |
| 329 | xfree(password); |
| 330 | break; |
| 331 | |
| 332 | #ifdef SKEY |
| 333 | case SSH_CMSG_AUTH_TIS: |
| 334 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
| 335 | if (options.skey_authentication == 1) { |
| 336 | char *skeyinfo = skey_keyinfo(pw->pw_name); |
| 337 | if (skeyinfo == NULL) { |
| 338 | debug("generating fake skeyinfo for %.100s.", pw->pw_name); |
| 339 | skeyinfo = skey_fake_keyinfo(pw->pw_name); |
| 340 | } |
| 341 | if (skeyinfo != NULL) { |
| 342 | /* we send our s/key- in tis-challenge messages */ |
| 343 | debug("sending challenge '%s'", skeyinfo); |
| 344 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
| 345 | packet_put_string(skeyinfo, strlen(skeyinfo)); |
| 346 | packet_send(); |
| 347 | packet_write_wait(); |
| 348 | continue; |
| 349 | } |
| 350 | } |
| 351 | break; |
| 352 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
| 353 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); |
| 354 | if (options.skey_authentication == 1) { |
| 355 | char *response = packet_get_string(&dlen); |
| 356 | debug("skey response == '%s'", response); |
| 357 | packet_integrity_check(plen, 4 + dlen, type); |
| 358 | authenticated = (skey_haskey(pw->pw_name) == 0 && |
| 359 | skey_passcheck(pw->pw_name, response) != -1); |
| 360 | xfree(response); |
| 361 | } |
| 362 | break; |
| 363 | #else |
| 364 | case SSH_CMSG_AUTH_TIS: |
| 365 | /* TIS Authentication is unsupported */ |
| 366 | log("TIS authentication unsupported."); |
| 367 | break; |
| 368 | #endif |
| 369 | |
| 370 | default: |
| 371 | /* |
| 372 | * Any unknown messages will be ignored (and failure |
| 373 | * returned) during authentication. |
| 374 | */ |
| 375 | log("Unknown message during authentication: type %d", type); |
| 376 | break; |
| 377 | } |
| 378 | |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 379 | #ifdef HAVE_CYGWIN |
| 380 | /* |
| 381 | * The only authentication which is able to change the user |
| 382 | * context on NT systems is the password authentication. So |
| 383 | * we deny all requsts for changing the user context if another |
| 384 | * authentication method is used. |
| 385 | * This may change in future when a special openssh |
| 386 | * subauthentication package is available. |
| 387 | */ |
| 388 | if (is_winnt && type != SSH_CMSG_AUTH_PASSWORD && |
| 389 | authenticated && geteuid() != pw->pw_uid) { |
| 390 | packet_disconnect("Authentication rejected for uid %d.", |
| 391 | (int) pw->pw_uid); |
| 392 | authenticated = 0; |
| 393 | } |
| 394 | #endif |
| 395 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 396 | /* |
| 397 | * Check if the user is logging in as root and root logins |
| 398 | * are disallowed. |
| 399 | * Note that root login is allowed for forced commands. |
| 400 | */ |
| 401 | if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) { |
| 402 | if (forced_command) { |
| 403 | log("Root login accepted for forced command."); |
| 404 | } else { |
| 405 | authenticated = 0; |
| 406 | log("ROOT LOGIN REFUSED FROM %.200s", |
| 407 | get_canonical_hostname()); |
| 408 | } |
| 409 | } |
| 410 | |
| 411 | /* Raise logging level */ |
| 412 | if (authenticated || |
| 413 | attempt == AUTH_FAIL_LOG || |
| 414 | type == SSH_CMSG_AUTH_PASSWORD) |
| 415 | authlog = log; |
| 416 | |
| 417 | authlog("%s %s for %.200s from %.200s port %d%s", |
| 418 | authenticated ? "Accepted" : "Failed", |
| 419 | get_authname(type), |
| 420 | pw->pw_uid == 0 ? "ROOT" : pw->pw_name, |
| 421 | get_remote_ipaddr(), |
| 422 | get_remote_port(), |
| 423 | user); |
| 424 | |
| 425 | #ifdef USE_PAM |
| 426 | if (authenticated) { |
| 427 | if (!do_pam_account(pw->pw_name, client_user)) { |
| 428 | if (client_user != NULL) { |
| 429 | xfree(client_user); |
| 430 | client_user = NULL; |
| 431 | } |
| 432 | do_fake_authloop1(pw->pw_name); |
| 433 | } |
| 434 | return; |
| 435 | } |
| 436 | #else /* USE_PAM */ |
| 437 | if (authenticated) { |
| 438 | return; |
| 439 | } |
| 440 | #endif /* USE_PAM */ |
| 441 | |
| 442 | if (client_user != NULL) { |
| 443 | xfree(client_user); |
| 444 | client_user = NULL; |
| 445 | } |
| 446 | |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 447 | if (attempt > AUTH_FAIL_MAX) { |
| 448 | #ifdef WITH_AIXAUTHENTICATE |
| 449 | loginfailed(pw->pw_name,get_canonical_hostname(),"ssh"); |
| 450 | #endif /* WITH_AIXAUTHENTICATE */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 451 | packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 452 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 453 | |
| 454 | /* Send a message indicating that the authentication attempt failed. */ |
| 455 | packet_start(SSH_SMSG_FAILURE); |
| 456 | packet_send(); |
| 457 | packet_write_wait(); |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | /* |
| 462 | * Performs authentication of an incoming connection. Session key has already |
| 463 | * been exchanged and encryption is enabled. |
| 464 | */ |
| 465 | void |
| 466 | do_authentication() |
| 467 | { |
| 468 | struct passwd *pw, pwcopy; |
| 469 | int plen; |
| 470 | unsigned int ulen; |
| 471 | char *user; |
| 472 | #ifdef WITH_AIXAUTHENTICATE |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 473 | extern char *aixloginmsg; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 474 | #endif /* WITH_AIXAUTHENTICATE */ |
| 475 | |
| 476 | /* Get the name of the user that we wish to log in as. */ |
| 477 | packet_read_expect(&plen, SSH_CMSG_USER); |
| 478 | |
| 479 | /* Get the user name. */ |
| 480 | user = packet_get_string(&ulen); |
| 481 | packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); |
| 482 | |
| 483 | setproctitle("%s", user); |
| 484 | |
| 485 | #ifdef AFS |
| 486 | /* If machine has AFS, set process authentication group. */ |
| 487 | if (k_hasafs()) { |
| 488 | k_setpag(); |
| 489 | k_unlog(); |
| 490 | } |
| 491 | #endif /* AFS */ |
| 492 | |
| 493 | /* Verify that the user is a valid user. */ |
| 494 | pw = getpwnam(user); |
| 495 | if (!pw || !allowed_user(pw)) |
| 496 | do_fake_authloop1(user); |
| 497 | xfree(user); |
| 498 | |
| 499 | /* Take a copy of the returned structure. */ |
| 500 | memset(&pwcopy, 0, sizeof(pwcopy)); |
| 501 | pwcopy.pw_name = xstrdup(pw->pw_name); |
| 502 | pwcopy.pw_passwd = xstrdup(pw->pw_passwd); |
| 503 | pwcopy.pw_uid = pw->pw_uid; |
| 504 | pwcopy.pw_gid = pw->pw_gid; |
Damien Miller | ad833b3 | 2000-08-23 10:46:23 +1000 | [diff] [blame] | 505 | #ifdef HAVE_PW_CLASS_IN_PASSWD |
| 506 | pwcopy.pw_class = xstrdup(pw->pw_class); |
| 507 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 508 | pwcopy.pw_dir = xstrdup(pw->pw_dir); |
| 509 | pwcopy.pw_shell = xstrdup(pw->pw_shell); |
| 510 | pw = &pwcopy; |
| 511 | |
| 512 | #ifdef USE_PAM |
| 513 | start_pam(pw); |
| 514 | #endif |
| 515 | |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 516 | #ifndef HAVE_CYGWIN |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 517 | /* |
| 518 | * If we are not running as root, the user must have the same uid as |
| 519 | * the server. |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 520 | * Rule not valid on Windows systems. |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 521 | */ |
| 522 | if (getuid() != 0 && pw->pw_uid != getuid()) |
| 523 | packet_disconnect("Cannot change user when server not running as root."); |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 524 | #endif |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 525 | |
| 526 | debug("Attempting authentication for %.100s.", pw->pw_name); |
| 527 | |
| 528 | /* If the user has no password, accept authentication immediately. */ |
| 529 | if (options.password_authentication && |
| 530 | #ifdef KRB4 |
| 531 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && |
| 532 | #endif /* KRB4 */ |
| 533 | #ifdef USE_PAM |
| 534 | auth_pam_password(pw, "")) { |
Damien Miller | d8cfda6 | 2000-07-01 12:56:09 +1000 | [diff] [blame] | 535 | #elif defined(HAVE_OSF_SIA) |
| 536 | (sia_validate_user(NULL, saved_argc, saved_argv, |
| 537 | get_canonical_hostname(), pw->pw_name, NULL, 0, NULL, |
| 538 | "") == SIASUCCESS)) { |
| 539 | #else /* !HAVE_OSF_SIA && !USE_PAM */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 540 | auth_password(pw, "")) { |
| 541 | #endif /* USE_PAM */ |
| 542 | /* Authentication with empty password succeeded. */ |
| 543 | log("Login for user %s from %.100s, accepted without authentication.", |
| 544 | pw->pw_name, get_remote_ipaddr()); |
| 545 | } else { |
| 546 | /* Loop until the user has been authenticated or the |
| 547 | connection is closed, do_authloop() returns only if |
| 548 | authentication is successfull */ |
| 549 | do_authloop(pw); |
| 550 | } |
| 551 | |
| 552 | /* The user has been authenticated and accepted. */ |
| 553 | #ifdef WITH_AIXAUTHENTICATE |
Damien Miller | d2c208a | 2000-05-17 22:00:02 +1000 | [diff] [blame] | 554 | /* We don't have a pty yet, so just label the line as "ssh" */ |
| 555 | if (loginsuccess(user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0) |
| 556 | aixloginmsg = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 557 | #endif /* WITH_AIXAUTHENTICATE */ |
| 558 | packet_start(SSH_SMSG_SUCCESS); |
| 559 | packet_send(); |
| 560 | packet_write_wait(); |
| 561 | |
| 562 | /* Perform session preparation. */ |
| 563 | do_authenticated(pw); |
| 564 | } |