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 2 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, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.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(const DATA_BLOB *nt_response,
  34                                  const uchar *part_passwd,
  35                                  const DATA_BLOB *sec_blob,
  36                                  DATA_BLOB *user_sess_key)
  37 {
  38         /* Finish the encryption of part_passwd. */
  39         uchar p24[24];
  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         SMBOWFencrypt(part_passwd, sec_blob->data, p24);
  60         if (user_sess_key != NULL) {
  61                 *user_sess_key = data_blob(NULL, 16);
  62                 SMBsesskeygen_ntv1(part_passwd, NULL, user_sess_key->data);
  63         }
  64
  65
  66 #ifdef DEBUG_PASSWORD
  67         DEBUG(100,("Part password (P16) was |\n"));
  68         dump_data(100, part_passwd, 16);
  69         DEBUGADD(100,("Password from client was |\n"));
  70         dump_data(100, nt_response->data, nt_response->length);
  71         DEBUGADD(100,("Given challenge was |\n"));
  72         dump_data(100, sec_blob->data, sec_blob->length);
  73         DEBUGADD(100,("Value from encryption was |\n"));
  74         dump_data(100, p24, 24);
  75 #endif
  76         return (memcmp(p24, nt_response->data, 24) == 0);
  77 }
  78
  79 /****************************************************************************
  80  Core of smb password checking routine. (NTLMv2, LMv2)
  81  Note:  The same code works with both NTLMv2 and LMv2.
  82 ****************************************************************************/
  83
  84 static BOOL smb_pwd_check_ntlmv2(const DATA_BLOB *ntv2_response,
  85                                  const uchar *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         uchar kr[16];
  93         uchar value_from_encryption[16];
  94         uchar client_response[16];
  95         DATA_BLOB client_key_data;
  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         return (memcmp(value_from_encryption, client_response, 16) == 0);
 150 }
 151
 152 /**
 153  * Check a challenge-response password against the value of the NT or
 154  * LM password hash.
 155  *
 156  * @param mem_ctx talloc context
 157  * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
 158  * @param nt_response 'unicode' NT response to the challenge, or unicode password
 159  * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
 160  * @param username internal Samba username, for log messages
 161  * @param client_username username the client used
 162  * @param client_domain domain name the client used (may be mapped)
 163  * @param nt_pw MD4 unicode password from our passdb or similar
 164  * @param lm_pw LANMAN ASCII password from our passdb or similar
 165  * @param user_sess_key User session key
 166  * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
 167  */
 168
 169 NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
 170                              const DATA_BLOB *challenge,
 171                              const DATA_BLOB *lm_response,
 172                              const DATA_BLOB *nt_response,
 173                              const DATA_BLOB *lm_interactive_pwd,
 174                              const DATA_BLOB *nt_interactive_pwd,
 175                              const char *username,
 176                              const char *client_username,
 177                              const char *client_domain,
 178                              const uint8 *lm_pw, const uint8 *nt_pw,
 179                              DATA_BLOB *user_sess_key,
 180                              DATA_BLOB *lm_sess_key)
 181 {
 182         static const unsigned char zeros[8];
 183         if (nt_pw == NULL) {
 184                 DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n",
 185                          username));
 186         }
 187
 188         if (nt_interactive_pwd && nt_interactive_pwd->length && nt_pw) {
 189                 if (nt_interactive_pwd->length != 16) {
 190                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid NT password length (%d) supplied for user %s\n", (int)nt_interactive_pwd->length,
 191                                  username));
 192                         return NT_STATUS_WRONG_PASSWORD;
 193                 }
 194
 195                 if (memcmp(nt_interactive_pwd->data, nt_pw, 16) == 0) {
 196                         if (user_sess_key) {
 197                                 *user_sess_key = data_blob(NULL, 16);
 198                                 SMBsesskeygen_ntv1(nt_pw, NULL, user_sess_key->data);
 199                         }
 200                         return NT_STATUS_OK;
 201                 } else {
 202                         DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n",
 203                                  username));
 204                         return NT_STATUS_WRONG_PASSWORD;
 205                 }
 206
 207         } else if (lm_interactive_pwd && lm_interactive_pwd->length && lm_pw) {
 208                 if (lm_interactive_pwd->length != 16) {
 209                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid LANMAN password length (%d) supplied for user %s\n", (int)lm_interactive_pwd->length,
 210                                  username));
 211                         return NT_STATUS_WRONG_PASSWORD;
 212                 }
 213
 214                 if (!lp_lanman_auth()) {
 215                         DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
 216                                  username));
 217                         return NT_STATUS_WRONG_PASSWORD;
 218                 }
 219
 220                 if (memcmp(lm_interactive_pwd->data, lm_pw, 16) == 0) {
 221                         return NT_STATUS_OK;
 222                 } else {
 223                         DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n",
 224                                  username));
 225                         return NT_STATUS_WRONG_PASSWORD;
 226                 }
 227         }
 228
 229         /* Check for cleartext netlogon. Used by Exchange 5.5. */
 230         if (challenge->length == sizeof(zeros) &&
 231             (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
 232
 233                 DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
 234                          username));
 235                 if (nt_pw && nt_response->length) {
 236                         unsigned char pwhash[16];
 237                         mdfour(pwhash, nt_response->data, nt_response->length);
 238                         if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
 239                                 return NT_STATUS_OK;
 240                         } else {
 241                                 DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
 242                                          username));
 243                                 return NT_STATUS_WRONG_PASSWORD;
 244                         }
 245
 246                 } else if (!lp_lanman_auth()) {
 247                         DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
 248                                  username));
 249
 250                 } else if (lm_pw && lm_response->length) {
 251                         uchar dospwd[14];
 252                         uchar p16[16];
 253                         ZERO_STRUCT(dospwd);
 254
 255                         memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
 256                         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
 257
 258                         /* we *might* need to upper-case the string here */
 259                         E_P16((const unsigned char *)dospwd, p16);
 260
 261                         if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
 262                                 return NT_STATUS_OK;
 263                         } else {
 264                                 DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
 265                                          username));
 266                                 return NT_STATUS_WRONG_PASSWORD;
 267                         }
 268                 } else {
 269                         DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
 270                         return NT_STATUS_WRONG_PASSWORD;
 271                 }
 272         }
 273
 274         if (nt_response->length != 0 && nt_response->length < 24) {
 275                 DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n",
 276                          (unsigned long)nt_response->length, username));
 277         }
 278
 279         if (nt_response->length >= 24 && nt_pw) {
 280                 if (nt_response->length > 24) {
 281                         /* We have the NT MD4 hash challenge available - see if we can
 282                            use it
 283                         */
 284                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
 285                         if (smb_pwd_check_ntlmv2( nt_response,
 286                                                   nt_pw, challenge,
 287                                                   client_username,
 288                                                   client_domain,
 289                                                   False,
 290                                                   user_sess_key)) {
 291                                 return NT_STATUS_OK;
 292                         }
 293
 294                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n", client_domain));
 295                         if (smb_pwd_check_ntlmv2( nt_response,
 296                                                   nt_pw, challenge,
 297                                                   client_username,
 298                                                   client_domain,
 299                                                   True,
 300                                                   user_sess_key)) {
 301                                 return NT_STATUS_OK;
 302                         }
 303
 304                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
 305                         if (smb_pwd_check_ntlmv2( nt_response,
 306                                                   nt_pw, challenge,
 307                                                   client_username,
 308                                                   "",
 309                                                   False,
 310                                                   user_sess_key)) {
 311                                 return NT_STATUS_OK;
 312                         } else {
 313                                 DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
 314                                 return NT_STATUS_WRONG_PASSWORD;
 315                         }
 316                 }
 317
 318                 if (lp_ntlm_auth()) {
 319                         /* We have the NT MD4 hash challenge available - see if we can
 320                            use it (ie. does it exist in the smbpasswd file).
 321                         */
 322                         DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
 323                         if (smb_pwd_check_ntlmv1(nt_response,
 324                                                  nt_pw, challenge,
 325                                                  user_sess_key)) {
 326                                 /* The LM session key for this response is not very secure,
 327                                    so use it only if we otherwise allow LM authentication */
 328
 329                                 if (lp_lanman_auth() && lm_pw) {
 330                                         uint8 first_8_lm_hash[16];
 331                                         memcpy(first_8_lm_hash, lm_pw, 8);
 332                                         memset(first_8_lm_hash + 8, '\0', 8);
 333                                         if (lm_sess_key) {
 334                                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 335                                         }
 336                                 }
 337                                 return NT_STATUS_OK;
 338                         } else {
 339                                 DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
 340                                          username));
 341                                 return NT_STATUS_WRONG_PASSWORD;
 342                         }
 343                 } else {
 344                         DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
 345                                  username));
 346                         /* no return, becouse we might pick up LMv2 in the LM field */
 347                 }
 348         }
 349
 350         if (lm_response->length == 0) {
 351                 DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
 352                          username));
 353                 return NT_STATUS_WRONG_PASSWORD;
 354         }
 355
 356         if (lm_response->length < 24) {
 357                 DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n",
 358                          (unsigned long)nt_response->length, username));
 359                 return NT_STATUS_WRONG_PASSWORD;
 360         }
 361
 362         if (!lp_lanman_auth()) {
 363                 DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
 364                          username));
 365         } else if (!lm_pw) {
 366                 DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
 367                          username));
 368         } else {
 369                 DEBUG(4,("ntlm_password_check: Checking LM password\n"));
 370                 if (smb_pwd_check_ntlmv1(lm_response,
 371                                          lm_pw, challenge,
 372                                          NULL)) {
 373                         uint8 first_8_lm_hash[16];
 374                         memcpy(first_8_lm_hash, lm_pw, 8);
 375                         memset(first_8_lm_hash + 8, '\0', 8);
 376                         if (user_sess_key) {
 377                                 *user_sess_key = data_blob(first_8_lm_hash, 16);
 378                         }
 379
 380                         if (lm_sess_key) {
 381                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 382                         }
 383                         return NT_STATUS_OK;
 384                 }
 385         }
 386
 387         if (!nt_pw) {
 388                 DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
 389                 return NT_STATUS_WRONG_PASSWORD;
 390         }
 391
 392         /* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
 393            - related to Win9X, legacy NAS pass-though authentication
 394         */
 395         DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain));
 396         if (smb_pwd_check_ntlmv2( lm_response,
 397                                   nt_pw, challenge,
 398                                   client_username,
 399                                   client_domain,
 400                                   False,
 401                                   NULL)) {
 402                 return NT_STATUS_OK;
 403         }
 404
 405         DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n", client_domain));
 406         if (smb_pwd_check_ntlmv2( lm_response,
 407                                   nt_pw, challenge,
 408                                   client_username,
 409                                   client_domain,
 410                                   True,
 411                                   NULL)) {
 412                 return NT_STATUS_OK;
 413         }
 414
 415         DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
 416         if (smb_pwd_check_ntlmv2( lm_response,
 417                                   nt_pw, challenge,
 418                                   client_username,
 419                                   "",
 420                                   False,
 421                                   NULL)) {
 422                 return NT_STATUS_OK;
 423         }
 424
 425         /* Apparently NT accepts NT responses in the LM field
 426            - I think this is related to Win9X pass-though authentication
 427         */
 428         DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
 429         if (lp_ntlm_auth()) {
 430                 if (smb_pwd_check_ntlmv1(lm_response,
 431                                          nt_pw, challenge,
 432                                          NULL)) {
 433                         /* The session key for this response is still very odd.
 434                            It not very secure, so use it only if we otherwise
 435                            allow LM authentication */
 436
 437                         if (lp_lanman_auth() && lm_pw) {
 438                                 uint8 first_8_lm_hash[16];
 439                                 memcpy(first_8_lm_hash, lm_pw, 8);
 440                                 memset(first_8_lm_hash + 8, '\0', 8);
 441                                 if (user_sess_key) {
 442                                         *user_sess_key = data_blob(first_8_lm_hash, 16);
 443                                 }
 444
 445                                 if (lm_sess_key) {
 446                                         *lm_sess_key = data_blob(first_8_lm_hash, 16);
 447                                 }
 448                         }
 449                         return NT_STATUS_OK;
 450                 }
 451                 DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
 452         } else {
 453                 DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
 454         }
 455         return NT_STATUS_WRONG_PASSWORD;
 456 }
 457