source/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 #ifdef 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(const DATA_BLOB *ntv2_response,
  84                                  const uchar *part_passwd,
  85                                  const DATA_BLOB *sec_blob,
  86                                  const char *user, const char *domain,
  87                                  BOOL upper_case_domain, /* should the domain be transformed into upper case? */
  88                                  DATA_BLOB *user_sess_key)
  89 {
  90         /* Finish the encryption of part_passwd. */
  91         uchar kr[16];
  92         uchar value_from_encryption[16];
  93         uchar client_response[16];
  94         DATA_BLOB client_key_data;
  95         BOOL res;
  96
  97         if (part_passwd == NULL) {
  98                 DEBUG(10,("No password set - DISALLOWING access\n"));
  99                 /* No password set - always False */
 100                 return False;
 101         }
 102
 103         if (sec_blob->length != 8) {
 104                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n",
 105                           (unsigned long)sec_blob->length));
 106                 return False;
 107         }
 108
 109         if (ntv2_response->length < 24) {
 110                 /* We MUST have more than 16 bytes, or the stuff below will go
 111                    crazy.  No known implementation sends less than the 24 bytes
 112                    for LMv2, let alone NTLMv2. */
 113                 DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n",
 114                           (unsigned long)ntv2_response->length));
 115                 return False;
 116         }
 117
 118         client_key_data = data_blob(ntv2_response->data+16, ntv2_response->length-16);
 119         /*
 120            todo:  should we be checking this for anything?  We can't for LMv2,
 121            but for NTLMv2 it is meant to contain the current time etc.
 122         */
 123
 124         memcpy(client_response, ntv2_response->data, sizeof(client_response));
 125
 126         if (!ntv2_owf_gen(part_passwd, user, domain, upper_case_domain, kr)) {
 127                 return False;
 128         }
 129
 130         SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption);
 131         if (user_sess_key != NULL) {
 132                 *user_sess_key = data_blob(NULL, 16);
 133                 SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data);
 134         }
 135
 136 #if DEBUG_PASSWORD
 137         DEBUG(100,("Part password (P16) was |\n"));
 138         dump_data(100, part_passwd, 16);
 139         DEBUGADD(100,("Password from client was |\n"));
 140         dump_data(100, ntv2_response->data, ntv2_response->length);
 141         DEBUGADD(100,("Variable data from client was |\n"));
 142         dump_data(100, client_key_data.data, client_key_data.length);
 143         DEBUGADD(100,("Given challenge was |\n"));
 144         dump_data(100, sec_blob->data, sec_blob->length);
 145         DEBUGADD(100,("Value from encryption was |\n"));
 146         dump_data(100, value_from_encryption, 16);
 147 #endif
 148         data_blob_clear_free(&client_key_data);
 149         res = (memcmp(value_from_encryption, client_response, 16) == 0);
 150         if ((!res) && (user_sess_key != NULL))
 151                 data_blob_clear_free(user_sess_key);
 152         return res;
 153 }
 154
 155 /**
 156  * Check a challenge-response password against the value of the NT or
 157  * LM password hash.
 158  *
 159  * @param mem_ctx talloc context
 160  * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
 161  * @param nt_response 'unicode' NT response to the challenge, or unicode password
 162  * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
 163  * @param username internal Samba username, for log messages
 164  * @param client_username username the client used
 165  * @param client_domain domain name the client used (may be mapped)
 166  * @param nt_pw MD4 unicode password from our passdb or similar
 167  * @param lm_pw LANMAN ASCII password from our passdb or similar
 168  * @param user_sess_key User session key
 169  * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
 170  */
 171
 172 NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
 173                              const DATA_BLOB *challenge,
 174                              const DATA_BLOB *lm_response,
 175                              const DATA_BLOB *nt_response,
 176                              const DATA_BLOB *lm_interactive_pwd,
 177                              const DATA_BLOB *nt_interactive_pwd,
 178                              const char *username,
 179                              const char *client_username,
 180                              const char *client_domain,
 181                              const uint8 *lm_pw, const uint8 *nt_pw,
 182                              DATA_BLOB *user_sess_key,
 183                              DATA_BLOB *lm_sess_key)
 184 {
 185         static const unsigned char zeros[8] = { 0, };
 186         if (nt_pw == NULL) {
 187                 DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n",
 188                          username));
 189         }
 190
 191         if (nt_interactive_pwd && nt_interactive_pwd->length && nt_pw) {
 192                 if (nt_interactive_pwd->length != 16) {
 193                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid NT password length (%d) supplied for user %s\n", (int)nt_interactive_pwd->length,
 194                                  username));
 195                         return NT_STATUS_WRONG_PASSWORD;
 196                 }
 197
 198                 if (memcmp(nt_interactive_pwd->data, nt_pw, 16) == 0) {
 199                         if (user_sess_key) {
 200                                 *user_sess_key = data_blob(NULL, 16);
 201                                 SMBsesskeygen_ntv1(nt_pw, NULL, user_sess_key->data);
 202                         }
 203                         return NT_STATUS_OK;
 204                 } else {
 205                         DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n",
 206                                  username));
 207                         return NT_STATUS_WRONG_PASSWORD;
 208                 }
 209
 210         } else if (lm_interactive_pwd && lm_interactive_pwd->length && lm_pw) {
 211                 if (lm_interactive_pwd->length != 16) {
 212                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid LANMAN password length (%d) supplied for user %s\n", (int)lm_interactive_pwd->length,
 213                                  username));
 214                         return NT_STATUS_WRONG_PASSWORD;
 215                 }
 216
 217                 if (!lp_lanman_auth()) {
 218                         DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
 219                                  username));
 220                         return NT_STATUS_WRONG_PASSWORD;
 221                 }
 222
 223                 if (memcmp(lm_interactive_pwd->data, lm_pw, 16) == 0) {
 224                         return NT_STATUS_OK;
 225                 } else {
 226                         DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n",
 227                                  username));
 228                         return NT_STATUS_WRONG_PASSWORD;
 229                 }
 230         }
 231
 232         /* Check for cleartext netlogon. Used by Exchange 5.5. */
 233         if (challenge->length == sizeof(zeros) &&
 234             (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
 235
 236                 DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
 237                          username));
 238                 if (nt_pw && nt_response->length) {
 239                         unsigned char pwhash[16];
 240                         mdfour(pwhash, nt_response->data, nt_response->length);
 241                         if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
 242                                 return NT_STATUS_OK;
 243                         } else {
 244                                 DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
 245                                          username));
 246                                 return NT_STATUS_WRONG_PASSWORD;
 247                         }
 248
 249                 } else if (!lp_lanman_auth()) {
 250                         DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
 251                                  username));
 252
 253                 } else if (lm_pw && lm_response->length) {
 254                         uchar dospwd[14];
 255                         uchar p16[16];
 256                         ZERO_STRUCT(dospwd);
 257
 258                         memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
 259                         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
 260
 261                         /* we *might* need to upper-case the string here */
 262                         E_P16((const unsigned char *)dospwd, p16);
 263
 264                         if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
 265                                 return NT_STATUS_OK;
 266                         } else {
 267                                 DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
 268                                          username));
 269                                 return NT_STATUS_WRONG_PASSWORD;
 270                         }
 271                 } else {
 272                         DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
 273                         return NT_STATUS_WRONG_PASSWORD;
 274                 }
 275         }
 276
 277         if (nt_response->length != 0 && nt_response->length < 24) {
 278                 DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n",
 279                          (unsigned long)nt_response->length, username));
 280         }
 281
 282         if (nt_response->length >= 24 && nt_pw) {
 283                 if (nt_response->length > 24) {
 284                         /* We have the NT MD4 hash challenge available - see if we can
 285                            use it
 286                         */
 287                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
 288                         if (smb_pwd_check_ntlmv2( 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( nt_response,
 299                                                   nt_pw, challenge,
 300                                                   client_username,
 301                                                   client_domain,
 302                                                   True,
 303                                                   user_sess_key)) {
 304                                 return NT_STATUS_OK;
 305                         }
 306
 307                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
 308                         if (smb_pwd_check_ntlmv2( nt_response,
 309                                                   nt_pw, challenge,
 310                                                   client_username,
 311                                                   "",
 312                                                   False,
 313                                                   user_sess_key)) {
 314                                 return NT_STATUS_OK;
 315                         } else {
 316                                 DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
 317                                 return NT_STATUS_WRONG_PASSWORD;
 318                         }
 319                 }
 320
 321                 if (lp_ntlm_auth()) {
 322                         /* We have the NT MD4 hash challenge available - see if we can
 323                            use it (ie. does it exist in the smbpasswd file).
 324                         */
 325                         DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
 326                         if (smb_pwd_check_ntlmv1(nt_response,
 327                                                  nt_pw, challenge,
 328                                                  user_sess_key)) {
 329                                 /* The LM session key for this response is not very secure,
 330                                    so use it only if we otherwise allow LM authentication */
 331
 332                                 if (lp_lanman_auth() && lm_pw) {
 333                                         uint8 first_8_lm_hash[16];
 334                                         memcpy(first_8_lm_hash, lm_pw, 8);
 335                                         memset(first_8_lm_hash + 8, '\0', 8);
 336                                         if (lm_sess_key) {
 337                                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 338                                         }
 339                                 }
 340                                 return NT_STATUS_OK;
 341                         } else {
 342                                 DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
 343                                          username));
 344                                 return NT_STATUS_WRONG_PASSWORD;
 345                         }
 346                 } else {
 347                         DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
 348                                  username));
 349                         /* no return, becouse we might pick up LMv2 in the LM field */
 350                 }
 351         }
 352
 353         if (lm_response->length == 0) {
 354                 DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
 355                          username));
 356                 return NT_STATUS_WRONG_PASSWORD;
 357         }
 358
 359         if (lm_response->length < 24) {
 360                 DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n",
 361                          (unsigned long)nt_response->length, username));
 362                 return NT_STATUS_WRONG_PASSWORD;
 363         }
 364
 365         if (!lp_lanman_auth()) {
 366                 DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
 367                          username));
 368         } else if (!lm_pw) {
 369                 DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
 370                          username));
 371         } else {
 372                 DEBUG(4,("ntlm_password_check: Checking LM password\n"));
 373                 if (smb_pwd_check_ntlmv1(lm_response,
 374                                          lm_pw, challenge,
 375                                          NULL)) {
 376                         uint8 first_8_lm_hash[16];
 377                         memcpy(first_8_lm_hash, lm_pw, 8);
 378                         memset(first_8_lm_hash + 8, '\0', 8);
 379                         if (user_sess_key) {
 380                                 *user_sess_key = data_blob(first_8_lm_hash, 16);
 381                         }
 382
 383                         if (lm_sess_key) {
 384                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 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( lm_response,
 400                                   nt_pw, challenge,
 401                                   client_username,
 402                                   client_domain,
 403                                   False,
 404                                   NULL)) {
 405                 return NT_STATUS_OK;
 406         }
 407
 408         DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n", client_domain));
 409         if (smb_pwd_check_ntlmv2( lm_response,
 410                                   nt_pw, challenge,
 411                                   client_username,
 412                                   client_domain,
 413                                   True,
 414                                   NULL)) {
 415                 return NT_STATUS_OK;
 416         }
 417
 418         DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
 419         if (smb_pwd_check_ntlmv2( lm_response,
 420                                   nt_pw, challenge,
 421                                   client_username,
 422                                   "",
 423                                   False,
 424                                   NULL)) {
 425                 return NT_STATUS_OK;
 426         }
 427
 428         /* Apparently NT accepts NT responses in the LM field
 429            - I think this is related to Win9X pass-though authentication
 430         */
 431         DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
 432         if (lp_ntlm_auth()) {
 433                 if (smb_pwd_check_ntlmv1(lm_response,
 434                                          nt_pw, challenge,
 435                                          NULL)) {
 436                         /* The session key for this response is still very odd.
 437                            It not very secure, so use it only if we otherwise
 438                            allow LM authentication */
 439
 440                         if (lp_lanman_auth() && lm_pw) {
 441                                 uint8 first_8_lm_hash[16];
 442                                 memcpy(first_8_lm_hash, lm_pw, 8);
 443                                 memset(first_8_lm_hash + 8, '\0', 8);
 444                                 if (user_sess_key) {
 445                                         *user_sess_key = data_blob(first_8_lm_hash, 16);
 446                                 }
 447
 448                                 if (lm_sess_key) {
 449                                         *lm_sess_key = data_blob(first_8_lm_hash, 16);
 450                                 }
 451                         }
 452                         return NT_STATUS_OK;
 453                 }
 454                 DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
 455         } else {
 456                 DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
 457         }
 458         return NT_STATUS_WRONG_PASSWORD;
 459 }
 460