source3/libsmb/ntlm_check.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Tridgell              1992-2000
   5    Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   6    Copyright (C) Andrew Bartlett              2001-2003
   7    Copyright (C) Gerald Carter                2003
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24
  25 #undef DBGC_CLASS
  26 #define DBGC_CLASS DBGC_AUTH
  27
  28 /****************************************************************************
  29  Core of smb password checking routine.
  30 ****************************************************************************/
  31
  32 static bool smb_pwd_check_ntlmv1(const DATA_BLOB *nt_response,
  33                                  const uchar *part_passwd,
  34                                  const DATA_BLOB *sec_blob,
  35                                  DATA_BLOB *user_sess_key)
  36 {
  37         /* Finish the encryption of part_passwd. */
  38         uchar p24[24];
  39
  40         if (part_passwd == NULL) {
  41                 DEBUG(10,("No password set - DISALLOWING access\n"));
  42                 /* No password set - always false ! */
  43                 return false;
  44         }
  45
  46         if (sec_blob->length != 8) {
  47                 DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n",
  48                           (unsigned long)sec_blob->length));
  49                 return false;
  50         }
  51
  52         if (nt_response->length != 24) {
  53                 DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n",
  54                           (unsigned long)nt_response->length));
  55                 return false;
  56         }
  57
  58         SMBOWFencrypt(part_passwd, sec_blob->data, p24);
  59         if (user_sess_key != NULL) {
  60                 *user_sess_key = data_blob(NULL, 16);
  61                 SMBsesskeygen_ntv1(part_passwd, NULL, user_sess_key->data);
  62         }
  63
  64
  65 #if DEBUG_PASSWORD
  66         DEBUG(100,("Part password (P16) was |\n"));
  67         dump_data(100, part_passwd, 16);
  68         DEBUGADD(100,("Password from client was |\n"));
  69         dump_data(100, nt_response->data, nt_response->length);
  70         DEBUGADD(100,("Given challenge was |\n"));
  71         dump_data(100, sec_blob->data, sec_blob->length);
  72         DEBUGADD(100,("Value from encryption was |\n"));
  73         dump_data(100, p24, 24);
  74 #endif
  75         return (memcmp(p24, nt_response->data, 24) == 0);
  76 }
  77
  78 /****************************************************************************
  79  Core of smb password checking routine. (NTLMv2, LMv2)
  80  Note:  The same code works with both NTLMv2 and LMv2.
  81 ****************************************************************************/
  82
  83 static bool smb_pwd_check_ntlmv2(TALLOC_CTX *mem_ctx,
  84                                  const DATA_BLOB *ntv2_response,
  85                                  const uint8_t *part_passwd,
  86                                  const DATA_BLOB *sec_blob,
  87                                  const char *user, const char *domain,
  88                                  bool upper_case_domain, /* should the domain be transformed into upper case? */
  89                                  DATA_BLOB *user_sess_key)
  90 {
  91         /* Finish the encryption of part_passwd. */
  92         uint8_t kr[16];
  93         uint8_t value_from_encryption[16];
  94         uint8_t client_response[16];
  95         DATA_BLOB client_key_data;
  96         bool res;
  97
  98         if (part_passwd == NULL) {
  99                 DEBUG(10,("No password set - DISALLOWING access\n"));
 100                 /* No password set - always false */
 101                 return false;
 102         }
 103
 104         if (sec_blob->length != 8) {
 105                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n",
 106                           (unsigned long)sec_blob->length));
 107                 return false;
 108         }
 109
 110         if (ntv2_response->length < 24) {
 111                 /* We MUST have more than 16 bytes, or the stuff below will go
 112                    crazy.  No known implementation sends less than the 24 bytes
 113                    for LMv2, let alone NTLMv2. */
 114                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n",
 115                           (unsigned long)ntv2_response->length));
 116                 return false;
 117         }
 118
 119         client_key_data = data_blob_talloc(mem_ctx, ntv2_response->data+16, ntv2_response->length-16);
 120         /*
 121            todo:  should we be checking this for anything?  We can't for LMv2,
 122            but for NTLMv2 it is meant to contain the current time etc.
 123         */
 124
 125         memcpy(client_response, ntv2_response->data, sizeof(client_response));
 126
 127         if (!ntv2_owf_gen(part_passwd, user, domain, upper_case_domain, kr)) {
 128                 return false;
 129         }
 130
 131         SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption);
 132         if (user_sess_key != NULL) {
 133                 *user_sess_key = data_blob(NULL, 16);
 134                 SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data);
 135         }
 136
 137 #if DEBUG_PASSWORD
 138         DEBUG(100,("Part password (P16) was |\n"));
 139         dump_data(100, part_passwd, 16);
 140         DEBUGADD(100,("Password from client was |\n"));
 141         dump_data(100, ntv2_response->data, ntv2_response->length);
 142         DEBUGADD(100,("Variable data from client was |\n"));
 143         dump_data(100, client_key_data.data, client_key_data.length);
 144         DEBUGADD(100,("Given challenge was |\n"));
 145         dump_data(100, sec_blob->data, sec_blob->length);
 146         DEBUGADD(100,("Value from encryption was |\n"));
 147         dump_data(100, value_from_encryption, 16);
 148 #endif
 149         data_blob_clear_free(&client_key_data);
 150         res = (memcmp(value_from_encryption, client_response, 16) == 0);
 151         if ((!res) && (user_sess_key != NULL))
 152                 data_blob_clear_free(user_sess_key);
 153         return res;
 154 }
 155
 156 /**
 157  * Check a challenge-response password against the value of the NT or
 158  * LM password hash.
 159  *
 160  * @param mem_ctx talloc context
 161  * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
 162  * @param nt_response 'unicode' NT response to the challenge, or unicode password
 163  * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
 164  * @param username internal Samba username, for log messages
 165  * @param client_username username the client used
 166  * @param client_domain domain name the client used (may be mapped)
 167  * @param nt_pw MD4 unicode password from our passdb or similar
 168  * @param lm_pw LANMAN ASCII password from our passdb or similar
 169  * @param user_sess_key User session key
 170  * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
 171  */
 172
 173 NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
 174                              const DATA_BLOB *challenge,
 175                              const DATA_BLOB *lm_response,
 176                              const DATA_BLOB *nt_response,
 177                              const DATA_BLOB *lm_interactive_pwd,
 178                              const DATA_BLOB *nt_interactive_pwd,
 179                              const char *username,
 180                              const char *client_username,
 181                              const char *client_domain,
 182                              const uint8_t *lm_pw, const uint8_t *nt_pw,
 183                              DATA_BLOB *user_sess_key,
 184                              DATA_BLOB *lm_sess_key)
 185 {
 186         unsigned char zeros[8];
 187
 188         ZERO_STRUCT(zeros);
 189
 190         if (nt_pw == NULL) {
 191                 DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n",
 192                          username));
 193         }
 194
 195         if (nt_interactive_pwd && nt_interactive_pwd->length && nt_pw) {
 196                 if (nt_interactive_pwd->length != 16) {
 197                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid NT password length (%d) supplied for user %s\n", (int)nt_interactive_pwd->length,
 198                                  username));
 199                         return NT_STATUS_WRONG_PASSWORD;
 200                 }
 201
 202                 if (memcmp(nt_interactive_pwd->data, nt_pw, 16) == 0) {
 203                         if (user_sess_key) {
 204                                 *user_sess_key = data_blob(NULL, 16);
 205                                 SMBsesskeygen_ntv1(nt_pw, NULL, user_sess_key->data);
 206                         }
 207                         return NT_STATUS_OK;
 208                 } else {
 209                         DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n",
 210                                  username));
 211                         return NT_STATUS_WRONG_PASSWORD;
 212                 }
 213
 214         } else if (lm_interactive_pwd && lm_interactive_pwd->length && lm_pw) {
 215                 if (lm_interactive_pwd->length != 16) {
 216                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid LANMAN password length (%d) supplied for user %s\n", (int)lm_interactive_pwd->length,
 217                                  username));
 218                         return NT_STATUS_WRONG_PASSWORD;
 219                 }
 220
 221                 if (!lp_lanman_auth()) {
 222                         DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
 223                                  username));
 224                         return NT_STATUS_WRONG_PASSWORD;
 225                 }
 226
 227                 if (memcmp(lm_interactive_pwd->data, lm_pw, 16) == 0) {
 228                         return NT_STATUS_OK;
 229                 } else {
 230                         DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n",
 231                                  username));
 232                         return NT_STATUS_WRONG_PASSWORD;
 233                 }
 234         }
 235
 236         /* Check for cleartext netlogon. Used by Exchange 5.5. */
 237         if (challenge->length == sizeof(zeros) &&
 238             (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
 239
 240                 DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
 241                          username));
 242                 if (nt_pw && nt_response->length) {
 243                         unsigned char pwhash[16];
 244                         mdfour(pwhash, nt_response->data, nt_response->length);
 245                         if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
 246                                 return NT_STATUS_OK;
 247                         } else {
 248                                 DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
 249                                          username));
 250                                 return NT_STATUS_WRONG_PASSWORD;
 251                         }
 252
 253                 } else if (!lp_lanman_auth()) {
 254                         DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
 255                                  username));
 256
 257                 } else if (lm_pw && lm_response->length) {
 258                         uchar dospwd[14];
 259                         uchar p16[16];
 260                         ZERO_STRUCT(dospwd);
 261
 262                         memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
 263                         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
 264
 265                         /* we *might* need to upper-case the string here */
 266                         E_P16((const unsigned char *)dospwd, p16);
 267
 268                         if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
 269                                 return NT_STATUS_OK;
 270                         } else {
 271                                 DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
 272                                          username));
 273                                 return NT_STATUS_WRONG_PASSWORD;
 274                         }
 275                 } else {
 276                         DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
 277                         return NT_STATUS_WRONG_PASSWORD;
 278                 }
 279         }
 280
 281         if (nt_response->length != 0 && nt_response->length < 24) {
 282                 DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n",
 283                          (unsigned long)nt_response->length, username));
 284         }
 285
 286         if (nt_response->length >= 24 && nt_pw) {
 287                 if (nt_response->length > 24) {
 288                         /* We have the NT MD4 hash challenge available - see if we can
 289                            use it
 290                         */
 291                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
 292                         if (smb_pwd_check_ntlmv2(mem_ctx,
 293                                                   nt_response,
 294                                                   nt_pw, challenge,
 295                                                   client_username,
 296                                                   client_domain,
 297                                                   False,
 298                                                   user_sess_key)) {
 299                                 return NT_STATUS_OK;
 300                         }
 301
 302                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n", client_domain));
 303                         if (smb_pwd_check_ntlmv2(mem_ctx,
 304                                                   nt_response,
 305                                                   nt_pw, challenge,
 306                                                   client_username,
 307                                                   client_domain,
 308                                                   true,
 309                                                   user_sess_key)) {
 310                                 return NT_STATUS_OK;
 311                         }
 312
 313                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
 314                         if (smb_pwd_check_ntlmv2(mem_ctx,
 315                                                   nt_response,
 316                                                   nt_pw, challenge,
 317                                                   client_username,
 318                                                   "",
 319                                                   False,
 320                                                   user_sess_key)) {
 321                                 return NT_STATUS_OK;
 322                         } else {
 323                                 DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
 324                                 return NT_STATUS_WRONG_PASSWORD;
 325                         }
 326                 }
 327
 328                 if (lp_ntlm_auth()) {
 329                         /* We have the NT MD4 hash challenge available - see if we can
 330                            use it (ie. does it exist in the smbpasswd file).
 331                         */
 332                         DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
 333                         if (smb_pwd_check_ntlmv1(nt_response,
 334                                                  nt_pw, challenge,
 335                                                  user_sess_key)) {
 336                                 /* The LM session key for this response is not very secure,
 337                                    so use it only if we otherwise allow LM authentication */
 338
 339                                 if (lp_lanman_auth() && lm_pw) {
 340                                         uint8_t first_8_lm_hash[16];
 341                                         memcpy(first_8_lm_hash, lm_pw, 8);
 342                                         memset(first_8_lm_hash + 8, '\0', 8);
 343                                         if (lm_sess_key) {
 344                                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 345                                         }
 346                                 }
 347                                 return NT_STATUS_OK;
 348                         } else {
 349                                 DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
 350                                          username));
 351                                 return NT_STATUS_WRONG_PASSWORD;
 352                         }
 353                 } else {
 354                         DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
 355                                  username));
 356                         /* no return, becouse we might pick up LMv2 in the LM field */
 357                 }
 358         }
 359
 360         if (lm_response->length == 0) {
 361                 DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
 362                          username));
 363                 return NT_STATUS_WRONG_PASSWORD;
 364         }
 365
 366         if (lm_response->length < 24) {
 367                 DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n",
 368                          (unsigned long)nt_response->length, username));
 369                 return NT_STATUS_WRONG_PASSWORD;
 370         }
 371
 372         if (!lp_lanman_auth()) {
 373                 DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
 374                          username));
 375         } else if (!lm_pw) {
 376                 DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
 377                          username));
 378         } else {
 379                 DEBUG(4,("ntlm_password_check: Checking LM password\n"));
 380                 if (smb_pwd_check_ntlmv1(lm_response,
 381                                          lm_pw, challenge,
 382                                          NULL)) {
 383                         uint8_t first_8_lm_hash[16];
 384                         memcpy(first_8_lm_hash, lm_pw, 8);
 385                         memset(first_8_lm_hash + 8, '\0', 8);
 386                         if (user_sess_key) {
 387                                 *user_sess_key = data_blob(first_8_lm_hash, 16);
 388                         }
 389
 390                         if (lm_sess_key) {
 391                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 392                         }
 393                         return NT_STATUS_OK;
 394                 }
 395         }
 396
 397         if (!nt_pw) {
 398                 DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
 399                 return NT_STATUS_WRONG_PASSWORD;
 400         }
 401
 402         /* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
 403            - related to Win9X, legacy NAS pass-though authentication
 404         */
 405         DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain));
 406         if (smb_pwd_check_ntlmv2(mem_ctx,
 407                                  lm_response,
 408                                   nt_pw, challenge,
 409                                   client_username,
 410                                   client_domain,
 411                                   false,
 412                                   NULL)) {
 413                 return NT_STATUS_OK;
 414         }
 415
 416         DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n", client_domain));
 417         if (smb_pwd_check_ntlmv2(mem_ctx,
 418                                  lm_response,
 419                                   nt_pw, challenge,
 420                                   client_username,
 421                                   client_domain,
 422                                   true,
 423                                   NULL)) {
 424                 return NT_STATUS_OK;
 425         }
 426
 427         DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
 428         if (smb_pwd_check_ntlmv2(mem_ctx,
 429                                  lm_response,
 430                                   nt_pw, challenge,
 431                                   client_username,
 432                                   "",
 433                                   false,
 434                                   NULL)) {
 435                 return NT_STATUS_OK;
 436         }
 437
 438         /* Apparently NT accepts NT responses in the LM field
 439            - I think this is related to Win9X pass-though authentication
 440         */
 441         DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
 442         if (lp_ntlm_auth()) {
 443                 if (smb_pwd_check_ntlmv1(lm_response,
 444                                          nt_pw, challenge,
 445                                          NULL)) {
 446                         /* The session key for this response is still very odd.
 447                            It not very secure, so use it only if we otherwise
 448                            allow LM authentication */
 449
 450                         if (lp_lanman_auth() && lm_pw) {
 451                                 uint8_t first_8_lm_hash[16];
 452                                 memcpy(first_8_lm_hash, lm_pw, 8);
 453                                 memset(first_8_lm_hash + 8, '\0', 8);
 454                                 if (user_sess_key) {
 455                                         *user_sess_key = data_blob(first_8_lm_hash, 16);
 456                                 }
 457
 458                                 if (lm_sess_key) {
 459                                         *lm_sess_key = data_blob(first_8_lm_hash, 16);
 460                                 }
 461                         }
 462                         return NT_STATUS_OK;
 463                 }
 464                 DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
 465         } else {
 466                 DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
 467         }
 468         return NT_STATUS_WRONG_PASSWORD;
 469 }
 470