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, (const char *)part_passwd, 16);
  69         DEBUGADD(100,("Password from client was |\n"));
  70         dump_data(100, (const char *)nt_response->data, nt_response->length);
  71         DEBUGADD(100,("Given challenge was |\n"));
  72         dump_data(100, (const char *)sec_blob->data, sec_blob->length);
  73         DEBUGADD(100,("Value from encryption was |\n"));
  74         dump_data(100, (const char *)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         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(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, (const char *)part_passwd, 16);
 140         DEBUGADD(100,("Password from client was |\n"));
 141         dump_data(100, (const char *)ntv2_response->data, ntv2_response->length);
 142         DEBUGADD(100,("Variable data from client was |\n"));
 143         dump_data(100, (const char *)client_key_data.data, client_key_data.length);
 144         DEBUGADD(100,("Given challenge was |\n"));
 145         dump_data(100, (const char *)sec_blob->data, sec_blob->length);
 146         DEBUGADD(100,("Value from encryption was |\n"));
 147         dump_data(100, (const char *)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 *lm_pw, const uint8 *nt_pw,
 183                              DATA_BLOB *user_sess_key,
 184                              DATA_BLOB *lm_sess_key)
 185 {
 186         static const unsigned char zeros[8] = { 0, };
 187         if (nt_pw == NULL) {
 188                 DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n",
 189                          username));
 190         }
 191
 192         if (nt_interactive_pwd && nt_interactive_pwd->length && nt_pw) {
 193                 if (nt_interactive_pwd->length != 16) {
 194                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid NT password length (%d) supplied for user %s\n", (int)nt_interactive_pwd->length,
 195                                  username));
 196                         return NT_STATUS_WRONG_PASSWORD;
 197                 }
 198
 199                 if (memcmp(nt_interactive_pwd->data, nt_pw, 16) == 0) {
 200                         if (user_sess_key) {
 201                                 *user_sess_key = data_blob(NULL, 16);
 202                                 SMBsesskeygen_ntv1(nt_pw, NULL, user_sess_key->data);
 203                         }
 204                         return NT_STATUS_OK;
 205                 } else {
 206                         DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n",
 207                                  username));
 208                         return NT_STATUS_WRONG_PASSWORD;
 209                 }
 210
 211         } else if (lm_interactive_pwd && lm_interactive_pwd->length && lm_pw) {
 212                 if (lm_interactive_pwd->length != 16) {
 213                         DEBUG(3,("ntlm_password_check: Interactive logon: Invalid LANMAN password length (%d) supplied for user %s\n", (int)lm_interactive_pwd->length,
 214                                  username));
 215                         return NT_STATUS_WRONG_PASSWORD;
 216                 }
 217
 218                 if (!lp_lanman_auth()) {
 219                         DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n",
 220                                  username));
 221                         return NT_STATUS_WRONG_PASSWORD;
 222                 }
 223
 224                 if (memcmp(lm_interactive_pwd->data, lm_pw, 16) == 0) {
 225                         return NT_STATUS_OK;
 226                 } else {
 227                         DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n",
 228                                  username));
 229                         return NT_STATUS_WRONG_PASSWORD;
 230                 }
 231         }
 232
 233         /* Check for cleartext netlogon. Used by Exchange 5.5. */
 234         if (challenge->length == sizeof(zeros) &&
 235             (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
 236
 237                 DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
 238                          username));
 239                 if (nt_pw && nt_response->length) {
 240                         unsigned char pwhash[16];
 241                         mdfour(pwhash, nt_response->data, nt_response->length);
 242                         if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
 243                                 return NT_STATUS_OK;
 244                         } else {
 245                                 DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
 246                                          username));
 247                                 return NT_STATUS_WRONG_PASSWORD;
 248                         }
 249
 250                 } else if (!lp_lanman_auth()) {
 251                         DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
 252                                  username));
 253
 254                 } else if (lm_pw && lm_response->length) {
 255                         uchar dospwd[14];
 256                         uchar p16[16];
 257                         ZERO_STRUCT(dospwd);
 258
 259                         memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
 260                         /* Only the fisrt 14 chars are considered, password need not be null terminated. */
 261
 262                         /* we *might* need to upper-case the string here */
 263                         E_P16((const unsigned char *)dospwd, p16);
 264
 265                         if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
 266                                 return NT_STATUS_OK;
 267                         } else {
 268                                 DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
 269                                          username));
 270                                 return NT_STATUS_WRONG_PASSWORD;
 271                         }
 272                 } else {
 273                         DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
 274                         return NT_STATUS_WRONG_PASSWORD;
 275                 }
 276         }
 277
 278         if (nt_response->length != 0 && nt_response->length < 24) {
 279                 DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n",
 280                          (unsigned long)nt_response->length, username));
 281         }
 282
 283         if (nt_response->length >= 24 && nt_pw) {
 284                 if (nt_response->length > 24) {
 285                         /* We have the NT MD4 hash challenge available - see if we can
 286                            use it
 287                         */
 288                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
 289                         if (smb_pwd_check_ntlmv2( nt_response,
 290                                                   nt_pw, challenge,
 291                                                   client_username,
 292                                                   client_domain,
 293                                                   False,
 294                                                   user_sess_key)) {
 295                                 return NT_STATUS_OK;
 296                         }
 297
 298                         DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n", client_domain));
 299                         if (smb_pwd_check_ntlmv2( 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( nt_response,
 310                                                   nt_pw, challenge,
 311                                                   client_username,
 312                                                   "",
 313                                                   False,
 314                                                   user_sess_key)) {
 315                                 return NT_STATUS_OK;
 316                         } else {
 317                                 DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
 318                                 return NT_STATUS_WRONG_PASSWORD;
 319                         }
 320                 }
 321
 322                 if (lp_ntlm_auth()) {
 323                         /* We have the NT MD4 hash challenge available - see if we can
 324                            use it (ie. does it exist in the smbpasswd file).
 325                         */
 326                         DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
 327                         if (smb_pwd_check_ntlmv1(nt_response,
 328                                                  nt_pw, challenge,
 329                                                  user_sess_key)) {
 330                                 /* The LM session key for this response is not very secure,
 331                                    so use it only if we otherwise allow LM authentication */
 332
 333                                 if (lp_lanman_auth() && lm_pw) {
 334                                         uint8 first_8_lm_hash[16];
 335                                         memcpy(first_8_lm_hash, lm_pw, 8);
 336                                         memset(first_8_lm_hash + 8, '\0', 8);
 337                                         if (lm_sess_key) {
 338                                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 339                                         }
 340                                 }
 341                                 return NT_STATUS_OK;
 342                         } else {
 343                                 DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
 344                                          username));
 345                                 return NT_STATUS_WRONG_PASSWORD;
 346                         }
 347                 } else {
 348                         DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
 349                                  username));
 350                         /* no return, becouse we might pick up LMv2 in the LM field */
 351                 }
 352         }
 353
 354         if (lm_response->length == 0) {
 355                 DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
 356                          username));
 357                 return NT_STATUS_WRONG_PASSWORD;
 358         }
 359
 360         if (lm_response->length < 24) {
 361                 DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n",
 362                          (unsigned long)nt_response->length, username));
 363                 return NT_STATUS_WRONG_PASSWORD;
 364         }
 365
 366         if (!lp_lanman_auth()) {
 367                 DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
 368                          username));
 369         } else if (!lm_pw) {
 370                 DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
 371                          username));
 372         } else {
 373                 DEBUG(4,("ntlm_password_check: Checking LM password\n"));
 374                 if (smb_pwd_check_ntlmv1(lm_response,
 375                                          lm_pw, challenge,
 376                                          NULL)) {
 377                         uint8 first_8_lm_hash[16];
 378                         memcpy(first_8_lm_hash, lm_pw, 8);
 379                         memset(first_8_lm_hash + 8, '\0', 8);
 380                         if (user_sess_key) {
 381                                 *user_sess_key = data_blob(first_8_lm_hash, 16);
 382                         }
 383
 384                         if (lm_sess_key) {
 385                                 *lm_sess_key = data_blob(first_8_lm_hash, 16);
 386                         }
 387                         return NT_STATUS_OK;
 388                 }
 389         }
 390
 391         if (!nt_pw) {
 392                 DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
 393                 return NT_STATUS_WRONG_PASSWORD;
 394         }
 395
 396         /* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
 397            - related to Win9X, legacy NAS pass-though authentication
 398         */
 399         DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain));
 400         if (smb_pwd_check_ntlmv2( 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( lm_response,
 411                                   nt_pw, challenge,
 412                                   client_username,
 413                                   client_domain,
 414                                   True,
 415                                   NULL)) {
 416                 return NT_STATUS_OK;
 417         }
 418
 419         DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
 420         if (smb_pwd_check_ntlmv2( lm_response,
 421                                   nt_pw, challenge,
 422                                   client_username,
 423                                   "",
 424                                   False,
 425                                   NULL)) {
 426                 return NT_STATUS_OK;
 427         }
 428
 429         /* Apparently NT accepts NT responses in the LM field
 430            - I think this is related to Win9X pass-though authentication
 431         */
 432         DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
 433         if (lp_ntlm_auth()) {
 434                 if (smb_pwd_check_ntlmv1(lm_response,
 435                                          nt_pw, challenge,
 436                                          NULL)) {
 437                         /* The session key for this response is still very odd.
 438                            It not very secure, so use it only if we otherwise
 439                            allow LM authentication */
 440
 441                         if (lp_lanman_auth() && lm_pw) {
 442                                 uint8 first_8_lm_hash[16];
 443                                 memcpy(first_8_lm_hash, lm_pw, 8);
 444                                 memset(first_8_lm_hash + 8, '\0', 8);
 445                                 if (user_sess_key) {
 446                                         *user_sess_key = data_blob(first_8_lm_hash, 16);
 447                                 }
 448
 449                                 if (lm_sess_key) {
 450                                         *lm_sess_key = data_blob(first_8_lm_hash, 16);
 451                                 }
 452                         }
 453                         return NT_STATUS_OK;
 454                 }
 455                 DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
 456         } else {
 457                 DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
 458         }
 459         return NT_STATUS_WRONG_PASSWORD;
 460 }
 461