source4/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 2 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, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "lib/crypto/crypto.h"
  25
  26 #undef DBGC_CLASS
  27 #define DBGC_CLASS DBGC_AUTH
  28
  29 /****************************************************************************
  30  Core of smb password checking routine.
  31 ****************************************************************************/
  32
  33 static BOOL smb_pwd_check_ntlmv1(TALLOC_CTX *mem_ctx,
  34                                  const DATA_BLOB *nt_response,
  35                                  const uint8_t *part_passwd,
  36                                  const DATA_BLOB *sec_blob,
  37                                  DATA_BLOB *user_sess_key)
  38 {
  39         /* Finish the encryption of part_passwd. */
  40         uint8_t p24[24];
  41
  42         if (part_passwd == NULL) {
  43                 DEBUG(10,("No password set - DISALLOWING access\n"));
  44                 /* No password set - always false ! */
  45                 return False;
  46         }
  47
  48         if (sec_blob->length != 8) {
  49                 DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n",
  50                           (unsigned long)sec_blob->length));
  51                 return False;
  52         }
  53
  54         if (nt_response->length != 24) {
  55                 DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n",
  56                           (unsigned long)nt_response->length));
  57                 return False;
  58         }
  59
  60         SMBOWFencrypt(part_passwd, sec_blob->data, p24);
  61         if (user_sess_key != NULL) {
  62                 *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
  63                 SMBsesskeygen_ntv1(part_passwd, user_sess_key->data);
  64         }
  65
  66
  67 #if DEBUG_PASSWORD
  68         DEBUG(100,("Part password (P16) was |\n"));
  69         dump_data(100, part_passwd, 16);
  70         DEBUGADD(100,("Password from client was |\n"));
  71         dump_data(100, nt_response->data, nt_response->length);
  72         DEBUGADD(100,("Given challenge was |\n"));
  73         dump_data(100, sec_blob->data, sec_blob->length);
  74         DEBUGADD(100,("Value from encryption was |\n"));
  75         dump_data(100, p24, 24);
  76 #endif
  77         return (memcmp(p24, nt_response->data, 24) == 0);
  78 }
  79
  80 /****************************************************************************
  81  Core of smb password checking routine. (NTLMv2, LMv2)
  82  Note:  The same code works with both NTLMv2 and LMv2.
  83 ****************************************************************************/
  84
  85 static BOOL smb_pwd_check_ntlmv2(TALLOC_CTX *mem_ctx,
  86                                  const DATA_BLOB *ntv2_response,
  87                                  const uint8_t *part_passwd,
  88                                  const DATA_BLOB *sec_blob,
  89                                  const char *user, const char *domain,
  90                                  BOOL upper_case_domain, /* should the domain be transformed into upper case? */
  91                                  DATA_BLOB *user_sess_key)
  92 {
  93         /* Finish the encryption of part_passwd. */
  94         uint8_t kr[16];
  95         uint8_t value_from_encryption[16];
  96         uint8_t client_response[16];
  97         DATA_BLOB client_key_data;
  98
  99         if (part_passwd == NULL) {
 100                 DEBUG(10,("No password set - DISALLOWING access\n"));
 101                 /* No password set - always False */
 102                 return False;
 103         }
 104
 105         if (sec_blob->length != 8) {
 106                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n",
 107                           (unsigned long)sec_blob->length));
 108                 return False;
 109         }
 110
 111         if (ntv2_response->length < 24) {
 112                 /* We MUST have more than 16 bytes, or the stuff below will go
 113                    crazy.  No known implementation sends less than the 24 bytes
 114                    for LMv2, let alone NTLMv2. */
 115                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n",
 116                           (unsigned long)ntv2_response->length));
 117                 return False;
 118         }
 119
 120         client_key_data = data_blob_talloc(mem_ctx, ntv2_response->data+16, ntv2_response->length-16);
 121         /*
 122            todo:  should we be checking this for anything?  We can't for LMv2,
 123            but for NTLMv2 it is meant to contain the current time etc.
 124         */
 125
 126         memcpy(client_response, ntv2_response->data, sizeof(client_response));
 127
 128         if (!ntv2_owf_gen(part_passwd, user, domain, upper_case_domain, kr)) {
 129                 return False;
 130         }
 131
 132         SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption);
 133         if (user_sess_key != NULL) {
 134                 *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
 135                 SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data);
 136         }
 137
 138 #if DEBUG_PASSWORD
 139         DEBUG(100,("Part password (P16) was |\n"));
 140         dump_data(100, part_passwd, 16);
 141         DEBUGADD(100,("Password from client was |\n"));
 142         dump_data(100, ntv2_response->data, ntv2_response->length);
 143         DEBUGADD(100,("Variable data from client was |\n"));
 144         dump_data(100, client_key_data.data, client_key_data.length);
 145         DEBUGADD(100,("Given challenge was |\n"));
 146         dump_data(100, sec_blob->data, sec_blob->length);
 147         DEBUGADD(100,("Value from encryption was |\n"));
 148         dump_data(100, value_from_encryption, 16);
 149 #endif
 150         data_blob_clear_free(&client_key_data);
 151         return (memcmp(value_from_encryption, client_response, 16) == 0);
 152 }
 153
 154 /**
 155  * Check a challenge-response password against the value of the NT or
 156  * LM password hash.
 157  *
 158  * @param mem_ctx talloc context
 159  * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
 160  * @param nt_response 'unicode' NT response to the challenge, or unicode password
 161  * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
 162  * @param username internal Samba username, for log messages
 163  * @param client_username username the client used
 164  * @param client_domain domain name the client used (may be mapped)
 165  * @param nt_pw MD4 unicode password from our passdb or similar
 166  * @param lm_pw LANMAN ASCII password from our passdb or similar
 167  * @param user_sess_key User session key
 168  * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
 169  */
 170
 171 NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
 172                              const DATA_BLOB *challenge,
 173                              const DATA_BLOB *lm_response,
 174                              const DATA_BLOB *nt_response,
 175                              const DATA_BLOB *lm_interactive_password,
 176                              const DATA_BLOB *nt_interactive_password,
 177                              const char *username,
 178                              const char *client_username,
 179                              const char *client_domain,
 180                              const uint8_t *lm_pw, const uint8_t *nt_pw,
 181                              DATA_BLOB *user_sess_key,
 182                              DATA_BLOB *lm_sess_key)
 183 {
 184         static const uint8_t zeros[8];
 185         if (nt_pw == NULL) {
 186                 DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n",
 187                          username));
 188         }
 189
 190         if (nt_interactive_password && nt_interactive_password->length && nt_pw) {
 191                 if (nt_interactive_password->length != 16) {
 192                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid NT password length (%d) supplied for user %s\n", (int)nt_interactive_password->length,
 193                                  username));
 194                         return NT_STATUS_WRONG_PASSWORD;
 195                 }
 196
 197                 if (memcmp(nt_interactive_password->data, nt_pw, 16) == 0) {
 198                         if (user_sess_key) {
 199                                 *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
 200                                 SMBsesskeygen_ntv1(nt_pw, user_sess_key->data);
 201                         }
 202                         return NT_STATUS_OK;
 203                 } else {
 204                         DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n",
 205                                  username));
 206                         return NT_STATUS_WRONG_PASSWORD;
 207                 }
 208
 209         } else if (lm_interactive_password && lm_interactive_password->length && lm_pw) {
 210                 if (lm_interactive_password->length != 16) {
 211                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid LANMAN password length (%d) supplied for user %s\n", (int)lm_interactive_password->length,
 212                                  username));
 213                         return NT_STATUS_WRONG_PASSWORD;
 214                 }
 215
 216                 if (!lp_lanman_auth()) {
 217                         DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
 218                                  username));
 219                         return NT_STATUS_WRONG_PASSWORD;
 220                 }
 221
 222                 if (memcmp(lm_interactive_password->data, lm_pw, 16) == 0) {
 223                         return NT_STATUS_OK;
 224                 } else {
 225                         DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n",
 226                                  username));
 227                         return NT_STATUS_WRONG_PASSWORD;
 228                 }
 229         }
 230
 231         /* Check for cleartext netlogon. Used by Exchange 5.5. */
 232         if (challenge->length == sizeof(zeros) &&
 233             (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
 234
 235                 DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
 236                          username));
 237                 if (nt_pw && nt_response->length) {
 238                         uint8_t pwhash[16];
 239                         mdfour(pwhash, nt_response->data, nt_response->length);
 240                         if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
 241                                 return NT_STATUS_OK;
 242                         } else {
 243                                 DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
 244                                          username));
 245                                 return NT_STATUS_WRONG_PASSWORD;
 246                         }
 247
 248                 } else if (!lp_lanman_auth()) {
 249                         DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
 250                                  username));
 251
 252                 } else if (lm_pw && lm_response->length) {
 253                         uint8_t dospwd[14];
 254                         uint8_t p16[16];
 255                         ZERO_STRUCT(dospwd);
 256
 257                         memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
 258                         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
 259
 260                         /* we *might* need to upper-case the string here */
 261                         E_P16((const uint8_t *)dospwd, p16);
 262
 263                         if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
 264                                 return NT_STATUS_OK;
 265                         } else {
 266                                 DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
 267                                          username));
 268                                 return NT_STATUS_WRONG_PASSWORD;
 269                         }
 270                 } else {
 271                         DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
 272                         return NT_STATUS_WRONG_PASSWORD;
 273                 }
 274         }
 275
 276         if (nt_response->length != 0 && nt_response->length < 24) {
 277                 DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n",
 278                          (unsigned long)nt_response->length, username));
 279         }
 280
 281         if (nt_response->length >= 24 && nt_pw) {
 282                 if (nt_response->length > 24) {
 283                         /* We have the NT MD4 hash challenge available - see if we can
 284                            use it
 285                         */
 286                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
 287                         if (smb_pwd_check_ntlmv2(mem_ctx,
 288                                                  nt_response,
 289                                                  nt_pw, challenge,
 290                                                  client_username,
 291                                                  client_domain,
 292                                                  False,
 293                                                  user_sess_key)) {
 294                                 return NT_STATUS_OK;
 295                         }
 296
 297                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n", client_domain));
 298                         if (smb_pwd_check_ntlmv2(mem_ctx,
 299                                                  nt_response,
 300                                                  nt_pw, challenge,
 301                                                  client_username,
 302                                                  client_domain,
 303                                                  True,
 304                                                  user_sess_key)) {
 305                                 return NT_STATUS_OK;
 306                         }
 307
 308                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
 309                         if (smb_pwd_check_ntlmv2(mem_ctx,
 310                                                  nt_response,
 311                                                  nt_pw, challenge,
 312                                                  client_username,
 313                                                  "",
 314                                                  False,
 315                                                  user_sess_key)) {
 316                                 return NT_STATUS_OK;
 317                         } else {
 318                                 DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
 319                                 return NT_STATUS_WRONG_PASSWORD;
 320                         }
 321                 }
 322
 323                 if (lp_ntlm_auth()) {
 324                         /* We have the NT MD4 hash challenge available - see if we can
 325                            use it (ie. does it exist in the smbpasswd file).
 326                         */
 327                         DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
 328                         if (smb_pwd_check_ntlmv1(mem_ctx,
 329                                                  nt_response,
 330                                                  nt_pw, challenge,
 331                                                  user_sess_key)) {
 332                                 /* The LM session key for this response is not very secure,
 333                                    so use it only if we otherwise allow LM authentication */
 334
 335                                 if (lp_lanman_auth() && lm_pw) {
 336                                         *lm_sess_key = data_blob_talloc(mem_ctx, lm_pw, 8);
 337                                 }
 338                                 return NT_STATUS_OK;
 339                         } else {
 340                                 DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
 341                                          username));
 342                                 return NT_STATUS_WRONG_PASSWORD;
 343                         }
 344                 } else {
 345                         DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
 346                                  username));
 347                         /* no return, becouse we might pick up LMv2 in the LM field */
 348                 }
 349         }
 350
 351         if (lm_response->length == 0) {
 352                 DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
 353                          username));
 354                 return NT_STATUS_WRONG_PASSWORD;
 355         }
 356
 357         if (lm_response->length < 24) {
 358                 DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n",
 359                          (unsigned long)nt_response->length, username));
 360                 return NT_STATUS_WRONG_PASSWORD;
 361         }
 362
 363         if (!lp_lanman_auth()) {
 364                 DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
 365                          username));
 366         } else if (!lm_pw) {
 367                 DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
 368                          username));
 369         } else {
 370                 DEBUG(4,("ntlm_password_check: Checking LM password\n"));
 371                 if (smb_pwd_check_ntlmv1(mem_ctx,
 372                                          lm_response,
 373                                          lm_pw, challenge,
 374                                          NULL)) {
 375                         /* The session key for this response is still very odd.
 376                            It not very secure, so use it only if we otherwise
 377                            allow LM authentication */
 378
 379                         if (lp_lanman_auth() && lm_pw) {
 380                                 uint8_t first_8_lm_hash[16];
 381                                 memcpy(first_8_lm_hash, lm_pw, 8);
 382                                 memset(first_8_lm_hash + 8, '\0', 8);
 383                                 *user_sess_key = data_blob_talloc(mem_ctx, first_8_lm_hash, 16);
 384                                 *lm_sess_key = data_blob_talloc(mem_ctx, lm_pw, 8);
 385                         }
 386                         return NT_STATUS_OK;
 387                 }
 388         }
 389
 390         if (!nt_pw) {
 391                 DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
 392                 return NT_STATUS_WRONG_PASSWORD;
 393         }
 394
 395         /* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
 396            - related to Win9X, legacy NAS pass-though authentication
 397         */
 398         DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain));
 399         if (smb_pwd_check_ntlmv2(mem_ctx,
 400                                  lm_response,
 401                                  nt_pw, challenge,
 402                                  client_username,
 403                                  client_domain,
 404                                  False,
 405                                  NULL)) {
 406                 return NT_STATUS_OK;
 407         }
 408
 409         DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n", client_domain));
 410         if (smb_pwd_check_ntlmv2(mem_ctx,
 411                                  lm_response,
 412                                  nt_pw, challenge,
 413                                  client_username,
 414                                  client_domain,
 415                                  True,
 416                                  NULL)) {
 417                 return NT_STATUS_OK;
 418         }
 419
 420         DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
 421         if (smb_pwd_check_ntlmv2(mem_ctx,
 422                                  lm_response,
 423                                  nt_pw, challenge,
 424                                  client_username,
 425                                  "",
 426                                  False,
 427                                  NULL)) {
 428                 return NT_STATUS_OK;
 429         }
 430
 431         /* Apparently NT accepts NT responses in the LM field
 432            - I think this is related to Win9X pass-though authentication
 433         */
 434         DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
 435         if (lp_ntlm_auth()) {
 436                 if (smb_pwd_check_ntlmv1(mem_ctx,
 437                                          lm_response,
 438                                          nt_pw, challenge,
 439                                          NULL)) {
 440                         /* The session key for this response is still very odd.
 441                            It not very secure, so use it only if we otherwise
 442                            allow LM authentication */
 443
 444                         if (lp_lanman_auth() && lm_pw) {
 445                                 uint8_t first_8_lm_hash[16];
 446                                 memcpy(first_8_lm_hash, lm_pw, 8);
 447                                 memset(first_8_lm_hash + 8, '\0', 8);
 448                                 *user_sess_key = data_blob_talloc(mem_ctx, first_8_lm_hash, 16);
 449                                 *lm_sess_key = data_blob_talloc(mem_ctx, lm_pw, 8);
 450                         }
 451                         return NT_STATUS_OK;
 452                 }
 453                 DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
 454         } else {
 455                 DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
 456         }
 457         return NT_STATUS_WRONG_PASSWORD;
 458 }
 459