libcli/auth/ntlm_check.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2004
   5    Copyright (C) Gerald Carter                             2003
   6    Copyright (C) Luke Kenneth Casson Leighton         1996-2000
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "lib/crypto/md4.h"
  24 #include "librpc/gen_ndr/netlogon.h"
  25 #include "libcli/auth/libcli_auth.h"
  26
  27 /****************************************************************************
  28  Core of smb password checking routine.
  29 ****************************************************************************/
  30
  31 static bool smb_pwd_check_ntlmv1(TALLOC_CTX *mem_ctx,
  32                                  const DATA_BLOB *nt_response,
  33                                  const uint8_t *part_passwd,
  34                                  const DATA_BLOB *sec_blob,
  35                                  DATA_BLOB *user_sess_key)
  36 {
  37         /* Finish the encryption of part_passwd. */
  38         uint8_t p24[24];
  39         int rc;
  40
  41         if (part_passwd == NULL) {
  42                 DEBUG(10,("No password set - DISALLOWING access\n"));
  43                 /* No password set - always false ! */
  44                 return false;
  45         }
  46
  47         if (sec_blob->length != 8) {
  48                 DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n",
  49                           (unsigned long)sec_blob->length));
  50                 return false;
  51         }
  52
  53         if (nt_response->length != 24) {
  54                 DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n",
  55                           (unsigned long)nt_response->length));
  56                 return false;
  57         }
  58
  59         rc = SMBOWFencrypt(part_passwd, sec_blob->data, p24);
  60         if (rc != 0) {
  61                 return false;
  62         }
  63
  64 #if DEBUG_PASSWORD
  65         DEBUG(100,("Part password (P16) was |\n"));
  66         dump_data(100, part_passwd, 16);
  67         DEBUGADD(100,("Password from client was |\n"));
  68         dump_data(100, nt_response->data, nt_response->length);
  69         DEBUGADD(100,("Given challenge was |\n"));
  70         dump_data(100, sec_blob->data, sec_blob->length);
  71         DEBUGADD(100,("Value from encryption was |\n"));
  72         dump_data(100, p24, 24);
  73 #endif
  74         if (memcmp(p24, nt_response->data, 24) == 0) {
  75                 if (user_sess_key != NULL) {
  76                         *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
  77                         SMBsesskeygen_ntv1(part_passwd, user_sess_key->data);
  78                 }
  79                 return true;
  80         }
  81         return false;
  82 }
  83
  84 /****************************************************************************
  85  Core of smb password checking routine. (NTLMv2, LMv2)
  86  Note:  The same code works with both NTLMv2 and LMv2.
  87 ****************************************************************************/
  88
  89 static bool smb_pwd_check_ntlmv2(TALLOC_CTX *mem_ctx,
  90                                  const DATA_BLOB *ntv2_response,
  91                                  const uint8_t *part_passwd,
  92                                  const DATA_BLOB *sec_blob,
  93                                  const char *user, const char *domain,
  94                                  DATA_BLOB *user_sess_key)
  95 {
  96         /* Finish the encryption of part_passwd. */
  97         uint8_t kr[16];
  98         uint8_t value_from_encryption[16];
  99         DATA_BLOB client_key_data;
 100         NTSTATUS status;
 101
 102         if (part_passwd == NULL) {
 103                 DEBUG(10,("No password set - DISALLOWING access\n"));
 104                 /* No password set - always false */
 105                 return false;
 106         }
 107
 108         if (sec_blob->length != 8) {
 109                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n",
 110                           (unsigned long)sec_blob->length));
 111                 return false;
 112         }
 113
 114         if (ntv2_response->length < 24) {
 115                 /* We MUST have more than 16 bytes, or the stuff below will go
 116                    crazy.  No known implementation sends less than the 24 bytes
 117                    for LMv2, let alone NTLMv2. */
 118                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n",
 119                           (unsigned long)ntv2_response->length));
 120                 return false;
 121         }
 122
 123         client_key_data = data_blob_talloc(mem_ctx, ntv2_response->data+16, ntv2_response->length-16);
 124         /*
 125            todo:  should we be checking this for anything?  We can't for LMv2,
 126            but for NTLMv2 it is meant to contain the current time etc.
 127         */
 128
 129         if (!ntv2_owf_gen(part_passwd, user, domain, kr)) {
 130                 return false;
 131         }
 132
 133         status = SMBOWFencrypt_ntv2(kr,
 134                                     sec_blob,
 135                                     &client_key_data,
 136                                     value_from_encryption);
 137         if (!NT_STATUS_IS_OK(status)) {
 138                 return false;
 139         }
 140
 141 #if DEBUG_PASSWORD
 142         DEBUG(100,("Part password (P16) was |\n"));
 143         dump_data(100, part_passwd, 16);
 144         DEBUGADD(100,("Password from client was |\n"));
 145         dump_data(100, ntv2_response->data, ntv2_response->length);
 146         DEBUGADD(100,("Variable data from client was |\n"));
 147         dump_data(100, client_key_data.data, client_key_data.length);
 148         DEBUGADD(100,("Given challenge was |\n"));
 149         dump_data(100, sec_blob->data, sec_blob->length);
 150         DEBUGADD(100,("Value from encryption was |\n"));
 151         dump_data(100, value_from_encryption, 16);
 152 #endif
 153         data_blob_clear_free(&client_key_data);
 154         if (memcmp(value_from_encryption, ntv2_response->data, 16) == 0) {
 155                 if (user_sess_key != NULL) {
 156                         *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
 157                         if (user_sess_key->data == NULL) {
 158                                 DBG_ERR("data_blob_talloc failed\n");
 159                                 return false;
 160                         }
 161
 162                         status = SMBsesskeygen_ntv2(kr,
 163                                                     value_from_encryption,
 164                                                     user_sess_key->data);
 165                         if (!NT_STATUS_IS_OK(status)) {
 166                                 return false;
 167                         }
 168                 }
 169                 return true;
 170         }
 171         return false;
 172 }
 173
 174 /****************************************************************************
 175  Core of smb password checking routine. (NTLMv2, LMv2)
 176  Note:  The same code works with both NTLMv2 and LMv2.
 177 ****************************************************************************/
 178
 179 static bool smb_sess_key_ntlmv2(TALLOC_CTX *mem_ctx,
 180                                 const DATA_BLOB *ntv2_response,
 181                                 const uint8_t *part_passwd,
 182                                 const DATA_BLOB *sec_blob,
 183                                 const char *user, const char *domain,
 184                                 DATA_BLOB *user_sess_key)
 185 {
 186         /* Finish the encryption of part_passwd. */
 187         uint8_t kr[16];
 188         uint8_t value_from_encryption[16];
 189         DATA_BLOB client_key_data;
 190         NTSTATUS status;
 191
 192         if (part_passwd == NULL) {
 193                 DEBUG(10,("No password set - DISALLOWING access\n"));
 194                 /* No password set - always false */
 195                 return false;
 196         }
 197
 198         if (sec_blob->length != 8) {
 199                 DEBUG(0, ("smb_sess_key_ntlmv2: incorrect challenge size (%lu)\n",
 200                           (unsigned long)sec_blob->length));
 201                 return false;
 202         }
 203
 204         if (ntv2_response->length < 24) {
 205                 /* We MUST have more than 16 bytes, or the stuff below will go
 206                    crazy.  No known implementation sends less than the 24 bytes
 207                    for LMv2, let alone NTLMv2. */
 208                 DEBUG(0, ("smb_sess_key_ntlmv2: incorrect password length (%lu)\n",
 209                           (unsigned long)ntv2_response->length));
 210                 return false;
 211         }
 212
 213         client_key_data = data_blob_talloc(mem_ctx, ntv2_response->data+16, ntv2_response->length-16);
 214
 215         if (!ntv2_owf_gen(part_passwd, user, domain, kr)) {
 216                 return false;
 217         }
 218
 219         status = SMBOWFencrypt_ntv2(kr,
 220                                     sec_blob,
 221                                     &client_key_data,
 222                                     value_from_encryption);
 223         if (!NT_STATUS_IS_OK(status)) {
 224                 return false;
 225         }
 226         *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
 227         status = SMBsesskeygen_ntv2(kr,
 228                                     value_from_encryption,
 229                                     user_sess_key->data);
 230         if (!NT_STATUS_IS_OK(status)) {
 231                 return false;
 232         }
 233         return true;
 234 }
 235
 236 /**
 237  * Compare password hashes against those from the SAM
 238  *
 239  * @param mem_ctx talloc context
 240  * @param client_lanman LANMAN password hash, as supplied by the client
 241  * @param client_nt NT (MD4) password hash, as supplied by the client
 242  * @param username internal Samba username, for log messages
 243  * @param client_username username the client used
 244  * @param client_domain domain name the client used (may be mapped)
 245  * @param stored_lanman LANMAN password hash, as stored on the SAM
 246  * @param stored_nt NT (MD4) password hash, as stored on the SAM
 247  * @param user_sess_key User session key
 248  * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
 249  */
 250
 251 NTSTATUS hash_password_check(TALLOC_CTX *mem_ctx,
 252                              bool lanman_auth,
 253                              const struct samr_Password *client_lanman,
 254                              const struct samr_Password *client_nt,
 255                              const char *username,
 256                              const struct samr_Password *stored_lanman,
 257                              const struct samr_Password *stored_nt)
 258 {
 259         if (stored_nt == NULL) {
 260                 DEBUG(3,("hash_password_check: NO NT password stored for user %s.\n",
 261                          username));
 262         }
 263
 264         if (client_nt && stored_nt) {
 265                 if (memcmp(client_nt->hash, stored_nt->hash, sizeof(stored_nt->hash)) == 0) {
 266                         return NT_STATUS_OK;
 267                 } else {
 268                         DEBUG(3,("hash_password_check: Interactive logon: NT password check failed for user %s\n",
 269                                  username));
 270                         return NT_STATUS_WRONG_PASSWORD;
 271                 }
 272
 273         } else if (client_lanman && stored_lanman) {
 274                 if (!lanman_auth) {
 275                         DEBUG(3,("hash_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
 276                                  username));
 277                         return NT_STATUS_WRONG_PASSWORD;
 278                 }
 279                 if (strchr_m(username, '@')) {
 280                         return NT_STATUS_NOT_FOUND;
 281                 }
 282
 283                 if (memcmp(client_lanman->hash, stored_lanman->hash, sizeof(stored_lanman->hash)) == 0) {
 284                         return NT_STATUS_OK;
 285                 } else {
 286                         DEBUG(3,("hash_password_check: Interactive logon: LANMAN password check failed for user %s\n",
 287                                  username));
 288                         return NT_STATUS_WRONG_PASSWORD;
 289                 }
 290         }
 291         if (strchr_m(username, '@')) {
 292                 return NT_STATUS_NOT_FOUND;
 293         }
 294         return NT_STATUS_WRONG_PASSWORD;
 295 }
 296
 297 /**
 298  * Check a challenge-response password against the value of the NT or
 299  * LM password hash.
 300  *
 301  * @param mem_ctx talloc context
 302  * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
 303  * @param nt_response 'unicode' NT response to the challenge, or unicode password
 304  * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
 305  * @param username internal Samba username, for log messages
 306  * @param client_username username the client used
 307  * @param client_domain domain name the client used (may be mapped)
 308  * @param stored_lanman LANMAN ASCII password from our passdb or similar
 309  * @param stored_nt MD4 unicode password from our passdb or similar
 310  * @param user_sess_key User session key
 311  * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
 312  */
 313
 314 NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
 315                              bool lanman_auth,
 316                              enum ntlm_auth_level ntlm_auth,
 317                              uint32_t logon_parameters,
 318                              const DATA_BLOB *challenge,
 319                              const DATA_BLOB *lm_response,
 320                              const DATA_BLOB *nt_response,
 321                              const char *username,
 322                              const char *client_username,
 323                              const char *client_domain,
 324                              const struct samr_Password *stored_lanman,
 325                              const struct samr_Password *stored_nt,
 326                              DATA_BLOB *user_sess_key,
 327                              DATA_BLOB *lm_sess_key)
 328 {
 329         DATA_BLOB tmp_sess_key;
 330         const char *upper_client_domain = NULL;
 331
 332         if (ntlm_auth == NTLM_AUTH_DISABLED) {
 333                 DBG_WARNING("ntlm_password_check: NTLM authentication not "
 334                             "permitted by configuration.\n");
 335                 return NT_STATUS_NTLM_BLOCKED;
 336         }
 337
 338         if (client_domain != NULL) {
 339                 upper_client_domain = talloc_strdup_upper(mem_ctx, client_domain);
 340                 if (upper_client_domain == NULL) {
 341                         return NT_STATUS_NO_MEMORY;
 342                 }
 343         }
 344
 345         if (stored_nt == NULL) {
 346                 DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n",
 347                          username));
 348         }
 349
 350         *lm_sess_key = data_blob(NULL, 0);
 351         *user_sess_key = data_blob(NULL, 0);
 352
 353         /* Check for cleartext netlogon. Used by Exchange 5.5. */
 354         if ((logon_parameters & MSV1_0_CLEARTEXT_PASSWORD_ALLOWED)
 355             && challenge->length == 8
 356             && (all_zero(challenge->data, challenge->length))) {
 357                 struct samr_Password client_nt;
 358                 struct samr_Password client_lm;
 359                 char *unix_pw = NULL;
 360                 bool lm_ok;
 361                 size_t converted_size = 0;
 362
 363                 DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
 364                          username));
 365                 mdfour(client_nt.hash, nt_response->data, nt_response->length);
 366
 367                 if (lm_response->length &&
 368                     (convert_string_talloc(mem_ctx, CH_DOS, CH_UNIX,
 369                                           lm_response->data, lm_response->length,
 370                                            (void *)&unix_pw, &converted_size))) {
 371                         if (E_deshash(unix_pw, client_lm.hash)) {
 372                                 lm_ok = true;
 373                         } else {
 374                                 lm_ok = false;
 375                         }
 376                 } else {
 377                         lm_ok = false;
 378                 }
 379                 return hash_password_check(mem_ctx,
 380                                            lanman_auth,
 381                                            lm_ok ? &client_lm : NULL,
 382                                            nt_response->length ? &client_nt : NULL,
 383                                            username,
 384                                            stored_lanman, stored_nt);
 385         }
 386
 387         if (nt_response->length != 0 && nt_response->length < 24) {
 388                 DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n",
 389                          (unsigned long)nt_response->length, username));
 390         }
 391
 392         if (nt_response->length > 24 && stored_nt) {
 393                 /* We have the NT MD4 hash challenge available - see if we can
 394                    use it
 395                 */
 396                 DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n",
 397                         client_domain ? client_domain : "<NULL>"));
 398                 if (smb_pwd_check_ntlmv2(mem_ctx,
 399                                          nt_response,
 400                                          stored_nt->hash, challenge,
 401                                          client_username,
 402                                          client_domain,
 403                                          user_sess_key)) {
 404                         if (user_sess_key->length) {
 405                                 *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length));
 406                         }
 407                         return NT_STATUS_OK;
 408                 }
 409
 410                 DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n",
 411                         upper_client_domain ? upper_client_domain : "<NULL>"));
 412                 if (smb_pwd_check_ntlmv2(mem_ctx,
 413                                          nt_response,
 414                                          stored_nt->hash, challenge,
 415                                          client_username,
 416                                          upper_client_domain,
 417                                          user_sess_key)) {
 418                         if (user_sess_key->length) {
 419                                 *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length));
 420                         }
 421                         return NT_STATUS_OK;
 422                 }
 423
 424                 DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
 425                 if (smb_pwd_check_ntlmv2(mem_ctx,
 426                                          nt_response,
 427                                          stored_nt->hash, challenge,
 428                                          client_username,
 429                                          "",
 430                                          user_sess_key)) {
 431                         if (user_sess_key->length) {
 432                                 *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length));
 433                         }
 434                         return NT_STATUS_OK;
 435                 } else {
 436                         DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
 437                 }
 438         } else if (nt_response->length == 24 && stored_nt) {
 439                 if (ntlm_auth == NTLM_AUTH_ON
 440                     || (ntlm_auth == NTLM_AUTH_MSCHAPv2_NTLMV2_ONLY && (logon_parameters & MSV1_0_ALLOW_MSVCHAPV2))) {
 441                         /* We have the NT MD4 hash challenge available - see if we can
 442                            use it (ie. does it exist in the smbpasswd file).
 443                         */
 444                         DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
 445                         if (smb_pwd_check_ntlmv1(mem_ctx,
 446                                                  nt_response,
 447                                                  stored_nt->hash, challenge,
 448                                                  user_sess_key)) {
 449                                 /* The LM session key for this response is not very secure,
 450                                    so use it only if we otherwise allow LM authentication */
 451
 452                                 if (lanman_auth && stored_lanman) {
 453                                         *lm_sess_key = data_blob_talloc(mem_ctx, stored_lanman->hash, MIN(8, user_sess_key->length));
 454                                 }
 455                                 return NT_STATUS_OK;
 456                         } else {
 457                                 DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
 458                                          username));
 459                                 return NT_STATUS_WRONG_PASSWORD;
 460                         }
 461                 } else {
 462                         DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
 463                                  username));
 464                         /* no return, because we might pick up LMv2 in the LM field */
 465                 }
 466         }
 467
 468         if (lm_response->length == 0) {
 469                 DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
 470                          username));
 471                 return NT_STATUS_WRONG_PASSWORD;
 472         }
 473
 474         if (lm_response->length < 24) {
 475                 DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n",
 476                          (unsigned long)nt_response->length, username));
 477                 return NT_STATUS_WRONG_PASSWORD;
 478         }
 479
 480         if (!lanman_auth) {
 481                 DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
 482                          username));
 483         } else if (!stored_lanman) {
 484                 DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
 485                          username));
 486         } else if (strchr_m(username, '@')) {
 487                 DEBUG(3,("ntlm_password_check: NO LanMan password allowed for username@realm logins (user: %s)\n",
 488                          username));
 489         } else {
 490                 DEBUG(4,("ntlm_password_check: Checking LM password\n"));
 491                 if (smb_pwd_check_ntlmv1(mem_ctx,
 492                                          lm_response,
 493                                          stored_lanman->hash, challenge,
 494                                          NULL)) {
 495                         /* The session key for this response is still very odd.
 496                            It not very secure, so use it only if we otherwise
 497                            allow LM authentication */
 498
 499                         if (lanman_auth && stored_lanman) {
 500                                 uint8_t first_8_lm_hash[16];
 501                                 memcpy(first_8_lm_hash, stored_lanman->hash, 8);
 502                                 memset(first_8_lm_hash + 8, '\0', 8);
 503                                 *user_sess_key = data_blob_talloc(mem_ctx, first_8_lm_hash, 16);
 504                                 *lm_sess_key = data_blob_talloc(mem_ctx, stored_lanman->hash, 8);
 505                         }
 506                         return NT_STATUS_OK;
 507                 }
 508         }
 509
 510         if (!stored_nt) {
 511                 DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
 512                 return NT_STATUS_WRONG_PASSWORD;
 513         }
 514
 515         /* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
 516            - related to Win9X, legacy NAS pass-though authentication
 517         */
 518         DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n",
 519                 client_domain ? client_domain : "<NULL>"));
 520         if (smb_pwd_check_ntlmv2(mem_ctx,
 521                                  lm_response,
 522                                  stored_nt->hash, challenge,
 523                                  client_username,
 524                                  client_domain,
 525                                  &tmp_sess_key)) {
 526                 if (nt_response->length > 24) {
 527                         /* If NTLMv2 authentication has preceded us
 528                          * (even if it failed), then use the session
 529                          * key from that.  See the RPC-SAMLOGON
 530                          * torture test */
 531                         smb_sess_key_ntlmv2(mem_ctx,
 532                                             nt_response,
 533                                             stored_nt->hash, challenge,
 534                                             client_username,
 535                                             client_domain,
 536                                             user_sess_key);
 537                 } else {
 538                         /* Otherwise, use the LMv2 session key */
 539                         *user_sess_key = tmp_sess_key;
 540                 }
 541                 if (user_sess_key->length) {
 542                         *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length));
 543                 }
 544                 return NT_STATUS_OK;
 545         }
 546
 547         DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n",
 548                 upper_client_domain ? upper_client_domain : "<NULL>"));
 549         if (smb_pwd_check_ntlmv2(mem_ctx,
 550                                  lm_response,
 551                                  stored_nt->hash, challenge,
 552                                  client_username,
 553                                  upper_client_domain,
 554                                  &tmp_sess_key)) {
 555                 if (nt_response->length > 24) {
 556                         /* If NTLMv2 authentication has preceded us
 557                          * (even if it failed), then use the session
 558                          * key from that.  See the RPC-SAMLOGON
 559                          * torture test */
 560                         smb_sess_key_ntlmv2(mem_ctx,
 561                                             nt_response,
 562                                             stored_nt->hash, challenge,
 563                                             client_username,
 564                                             upper_client_domain,
 565                                             user_sess_key);
 566                 } else {
 567                         /* Otherwise, use the LMv2 session key */
 568                         *user_sess_key = tmp_sess_key;
 569                 }
 570                 if (user_sess_key->length) {
 571                         *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length));
 572                 }
 573                 return NT_STATUS_OK;
 574         }
 575
 576         DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
 577         if (smb_pwd_check_ntlmv2(mem_ctx,
 578                                  lm_response,
 579                                  stored_nt->hash, challenge,
 580                                  client_username,
 581                                  "",
 582                                  &tmp_sess_key)) {
 583                 if (nt_response->length > 24) {
 584                         /* If NTLMv2 authentication has preceded us
 585                          * (even if it failed), then use the session
 586                          * key from that.  See the RPC-SAMLOGON
 587                          * torture test */
 588                         smb_sess_key_ntlmv2(mem_ctx,
 589                                             nt_response,
 590                                             stored_nt->hash, challenge,
 591                                             client_username,
 592                                             "",
 593                                             user_sess_key);
 594                 } else {
 595                         /* Otherwise, use the LMv2 session key */
 596                         *user_sess_key = tmp_sess_key;
 597                 }
 598                 if (user_sess_key->length) {
 599                         *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length));
 600                 }
 601                 return NT_STATUS_OK;
 602         }
 603
 604         /* Apparently NT accepts NT responses in the LM field
 605            - I think this is related to Win9X pass-though authentication
 606         */
 607         DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
 608         if (ntlm_auth == NTLM_AUTH_ON) {
 609                 if (smb_pwd_check_ntlmv1(mem_ctx,
 610                                          lm_response,
 611                                          stored_nt->hash, challenge,
 612                                          NULL)) {
 613                         /* The session key for this response is still very odd.
 614                            It not very secure, so use it only if we otherwise
 615                            allow LM authentication */
 616
 617                         if (lanman_auth && stored_lanman) {
 618                                 uint8_t first_8_lm_hash[16];
 619                                 memcpy(first_8_lm_hash, stored_lanman->hash, 8);
 620                                 memset(first_8_lm_hash + 8, '\0', 8);
 621                                 *user_sess_key = data_blob_talloc(mem_ctx, first_8_lm_hash, 16);
 622                                 *lm_sess_key = data_blob_talloc(mem_ctx, stored_lanman->hash, 8);
 623                         }
 624                         return NT_STATUS_OK;
 625                 }
 626                 DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
 627         } else {
 628                 DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
 629         }
 630
 631         /* Try and match error codes */
 632         if (strchr_m(username, '@')) {
 633                 return NT_STATUS_NOT_FOUND;
 634         }
 635         return NT_STATUS_WRONG_PASSWORD;
 636 }
 637