source4/auth/ntlmssp/ntlmssp_client.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    handle NLTMSSP, client server side parsing
   5
   6    Copyright (C) Andrew Tridgell      2001
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2005
   8    Copyright (C) Stefan Metzmacher 2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "auth/auth.h"
  27 #include "auth/ntlmssp/ntlmssp.h"
  28 #include "lib/crypto/crypto.h"
  29
  30 /*********************************************************************
  31  Client side NTLMSSP
  32 *********************************************************************/
  33
  34 /**
  35  * Next state function for the Initial packet
  36  *
  37  * @param ntlmssp_state NTLMSSP State
  38  * @param out_mem_ctx The DATA_BLOB *out will be allocated on this context
  39  * @param in A NULL data blob (input ignored)
  40  * @param out The initial negotiate request to the server, as an talloc()ed DATA_BLOB, on out_mem_ctx
  41  * @return Errors or NT_STATUS_OK.
  42  */
  43
  44 NTSTATUS ntlmssp_client_initial(struct gensec_security *gensec_security,
  45                                 TALLOC_CTX *out_mem_ctx,
  46                                 DATA_BLOB in, DATA_BLOB *out)
  47 {
  48         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
  49
  50         if (gensec_ntlmssp_state->unicode) {
  51                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
  52         } else {
  53                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
  54         }
  55
  56         if (gensec_ntlmssp_state->use_ntlmv2) {
  57                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
  58         }
  59
  60         /* generate the ntlmssp negotiate packet */
  61         msrpc_gen(out_mem_ctx,
  62                   out, "CddAA",
  63                   "NTLMSSP",
  64                   NTLMSSP_NEGOTIATE,
  65                   gensec_ntlmssp_state->neg_flags,
  66                   gensec_ntlmssp_state->get_domain(),
  67                   cli_credentials_get_workstation(gensec_security->credentials));
  68
  69         gensec_ntlmssp_state->expected_state = NTLMSSP_CHALLENGE;
  70
  71         return NT_STATUS_MORE_PROCESSING_REQUIRED;
  72 }
  73
  74 /**
  75  * Next state function for the Challenge Packet.  Generate an auth packet.
  76  *
  77  * @param gensec_security GENSEC state
  78  * @param out_mem_ctx Memory context for *out
  79  * @param in The server challnege, as a DATA_BLOB.  reply.data must be NULL
  80  * @param out The next request (auth packet) to the server, as an allocated DATA_BLOB, on the out_mem_ctx context
  81  * @return Errors or NT_STATUS_OK.
  82  */
  83
  84 NTSTATUS ntlmssp_client_challenge(struct gensec_security *gensec_security,
  85                                   TALLOC_CTX *out_mem_ctx,
  86                                   const DATA_BLOB in, DATA_BLOB *out)
  87 {
  88         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
  89         uint32_t chal_flags, ntlmssp_command, unkn1, unkn2;
  90         DATA_BLOB server_domain_blob;
  91         DATA_BLOB challenge_blob;
  92         DATA_BLOB struct_blob = data_blob(NULL, 0);
  93         char *server_domain;
  94         const char *chal_parse_string;
  95         const char *auth_gen_string;
  96         uint8_t lm_hash[16];
  97         DATA_BLOB lm_response = data_blob(NULL, 0);
  98         DATA_BLOB nt_response = data_blob(NULL, 0);
  99         DATA_BLOB session_key = data_blob(NULL, 0);
 100         DATA_BLOB lm_session_key = data_blob(NULL, 0);
 101         DATA_BLOB encrypted_session_key = data_blob(NULL, 0);
 102         NTSTATUS nt_status;
 103
 104         const char *user, *domain, *password;
 105
 106         if (!msrpc_parse(out_mem_ctx,
 107                          &in, "CdBd",
 108                          "NTLMSSP",
 109                          &ntlmssp_command,
 110                          &server_domain_blob,
 111                          &chal_flags)) {
 112                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
 113                 dump_data(2, in.data, in.length);
 114
 115                 return NT_STATUS_INVALID_PARAMETER;
 116         }
 117
 118         data_blob_free(&server_domain_blob);
 119
 120         DEBUG(3, ("Got challenge flags:\n"));
 121         debug_ntlmssp_flags(chal_flags);
 122
 123         ntlmssp_handle_neg_flags(gensec_ntlmssp_state, chal_flags, gensec_ntlmssp_state->allow_lm_key);
 124
 125         if (gensec_ntlmssp_state->unicode) {
 126                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 127                         chal_parse_string = "CdUdbddB";
 128                 } else {
 129                         chal_parse_string = "CdUdbdd";
 130                 }
 131                 auth_gen_string = "CdBBUUUBd";
 132         } else {
 133                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 134                         chal_parse_string = "CdAdbddB";
 135                 } else {
 136                         chal_parse_string = "CdAdbdd";
 137                 }
 138
 139                 auth_gen_string = "CdBBAAABd";
 140         }
 141
 142         DEBUG(3, ("NTLMSSP: Set final flags:\n"));
 143         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 144
 145         if (!msrpc_parse(out_mem_ctx,
 146                          &in, chal_parse_string,
 147                          "NTLMSSP",
 148                          &ntlmssp_command,
 149                          &server_domain,
 150                          &chal_flags,
 151                          &challenge_blob, 8,
 152                          &unkn1, &unkn2,
 153                          &struct_blob)) {
 154                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
 155                 dump_data(2, in.data, in.length);
 156                 return NT_STATUS_INVALID_PARAMETER;
 157         }
 158
 159         gensec_ntlmssp_state->server_domain = server_domain;
 160
 161         if (challenge_blob.length != 8) {
 162                 return NT_STATUS_INVALID_PARAMETER;
 163         }
 164
 165         /* Correctly handle username in the original form of user@REALM, which is valid */
 166         if (gensec_security->credentials->realm_obtained
 167             > gensec_security->credentials->domain_obtained) {
 168                 user = talloc_asprintf(out_mem_ctx, "%s@%s",
 169                                        cli_credentials_get_username(gensec_security->credentials),
 170                                        cli_credentials_get_realm(gensec_security->credentials));
 171                 domain = NULL;
 172         } else {
 173                 user = cli_credentials_get_username(gensec_security->credentials);
 174                 domain = cli_credentials_get_domain(gensec_security->credentials);
 175         }
 176
 177         password = cli_credentials_get_password(gensec_security->credentials);
 178
 179         if (!password) {
 180                 static const uint8_t zeros[16];
 181                 /* do nothing - blobs are zero length */
 182
 183                 /* session key is all zeros */
 184                 session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
 185                 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
 186
 187                 /* not doing NLTM2 without a password */
 188                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 189         } else if (gensec_ntlmssp_state->use_ntlmv2) {
 190
 191                 if (!struct_blob.length) {
 192                         /* be lazy, match win2k - we can't do NTLMv2 without it */
 193                         DEBUG(1, ("Server did not provide 'target information', required for NTLMv2\n"));
 194                         return NT_STATUS_INVALID_PARAMETER;
 195                 }
 196
 197                 /* TODO: if the remote server is standalone, then we should replace 'domain'
 198                    with the server name as supplied above */
 199
 200                 if (!SMBNTLMv2encrypt(user,
 201                                       domain,
 202                                       password, &challenge_blob,
 203                                       &struct_blob,
 204                                       &lm_response, &nt_response,
 205                                       NULL, &session_key)) {
 206                         data_blob_free(&challenge_blob);
 207                         data_blob_free(&struct_blob);
 208                         return NT_STATUS_NO_MEMORY;
 209                 }
 210
 211                 /* LM Key is incompatible... */
 212                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 213
 214         } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 215                 struct MD5Context md5_session_nonce_ctx;
 216                 uint8_t nt_hash[16];
 217                 uint8_t session_nonce[16];
 218                 uint8_t session_nonce_hash[16];
 219                 uint8_t user_session_key[16];
 220                 E_md4hash(password, nt_hash);
 221
 222                 lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 223                 generate_random_buffer(lm_response.data, 8);
 224                 memset(lm_response.data+8, 0, 16);
 225
 226                 memcpy(session_nonce, challenge_blob.data, 8);
 227                 memcpy(&session_nonce[8], lm_response.data, 8);
 228
 229                 MD5Init(&md5_session_nonce_ctx);
 230                 MD5Update(&md5_session_nonce_ctx, challenge_blob.data, 8);
 231                 MD5Update(&md5_session_nonce_ctx, lm_response.data, 8);
 232                 MD5Final(session_nonce_hash, &md5_session_nonce_ctx);
 233
 234                 DEBUG(5, ("NTLMSSP challenge set by NTLM2\n"));
 235                 DEBUG(5, ("challenge is: \n"));
 236                 dump_data(5, session_nonce_hash, 8);
 237
 238                 nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 239                 SMBNTencrypt(password,
 240                              session_nonce_hash,
 241                              nt_response.data);
 242
 243                 session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 244
 245                 SMBsesskeygen_ntv1(nt_hash, user_session_key);
 246                 hmac_md5(user_session_key, session_nonce, sizeof(session_nonce), session_key.data);
 247                 dump_data_pw("NTLM2 session key:\n", session_key.data, session_key.length);
 248
 249                 /* LM Key is incompatible... */
 250                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 251         } else {
 252                 uint8_t nt_hash[16];
 253
 254                 if (gensec_ntlmssp_state->use_nt_response) {
 255                         nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 256                         SMBNTencrypt(password,challenge_blob.data,
 257                                      nt_response.data);
 258                         E_md4hash(password, nt_hash);
 259                         session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 260                         SMBsesskeygen_ntv1(nt_hash, session_key.data);
 261                         dump_data_pw("NT session key:\n", session_key.data, session_key.length);
 262                 }
 263
 264                 /* lanman auth is insecure, it may be disabled */
 265                 if (lp_client_lanman_auth()) {
 266                         lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 267                         if (!SMBencrypt(password,challenge_blob.data,
 268                                         lm_response.data)) {
 269                                 /* If the LM password was too long (and therefore the LM hash being
 270                                    of the first 14 chars only), don't send it */
 271                                 data_blob_free(&lm_response);
 272
 273                                 /* LM Key is incompatible with 'long' passwords */
 274                                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 275                         } else {
 276                                 E_deshash(password, lm_hash);
 277                                 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 278                                 memcpy(lm_session_key.data, lm_hash, 8);
 279                                 memset(&lm_session_key.data[8], '\0', 8);
 280
 281                                 if (!gensec_ntlmssp_state->use_nt_response) {
 282                                         session_key = lm_session_key;
 283                                 }
 284                         }
 285                 } else {
 286                         /* LM Key is incompatible... */
 287                         gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 288                 }
 289         }
 290
 291         if ((gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 292             && lp_client_lanman_auth() && lm_session_key.length == 16) {
 293                 DATA_BLOB new_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 294                 if (lm_response.length == 24) {
 295                         SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
 296                                                   new_session_key.data);
 297                 } else {
 298                         static const uint8_t zeros[24];
 299                         SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
 300                                                   new_session_key.data);
 301                 }
 302                 new_session_key.length = 16;
 303                 session_key = new_session_key;
 304                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 305         }
 306
 307
 308         /* Key exchange encryptes a new client-generated session key with
 309            the password-derived key */
 310         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 311                 /* Make up a new session key */
 312                 uint8_t client_session_key[16];
 313                 generate_random_buffer(client_session_key, sizeof(client_session_key));
 314
 315                 /* Encrypt the new session key with the old one */
 316                 encrypted_session_key = data_blob_talloc(gensec_ntlmssp_state,
 317                                                          client_session_key, sizeof(client_session_key));
 318                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 319                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 320                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 321
 322                 /* Mark the new session key as the 'real' session key */
 323                 session_key = data_blob_talloc(gensec_ntlmssp_state, client_session_key, sizeof(client_session_key));
 324         }
 325
 326         /* this generates the actual auth packet */
 327         if (!msrpc_gen(out_mem_ctx,
 328                        out, auth_gen_string,
 329                        "NTLMSSP",
 330                        NTLMSSP_AUTH,
 331                        lm_response.data, lm_response.length,
 332                        nt_response.data, nt_response.length,
 333                        domain,
 334                        user,
 335                        cli_credentials_get_workstation(gensec_security->credentials),
 336                        encrypted_session_key.data, encrypted_session_key.length,
 337                        gensec_ntlmssp_state->neg_flags)) {
 338
 339                 return NT_STATUS_NO_MEMORY;
 340         }
 341
 342         gensec_ntlmssp_state->session_key = session_key;
 343
 344         /* The client might be using 56 or 40 bit weakened keys */
 345         ntlmssp_weaken_keys(gensec_ntlmssp_state);
 346
 347         gensec_ntlmssp_state->chal = challenge_blob;
 348         gensec_ntlmssp_state->lm_resp = lm_response;
 349         gensec_ntlmssp_state->nt_resp = nt_response;
 350
 351         gensec_ntlmssp_state->expected_state = NTLMSSP_DONE;
 352
 353         nt_status = ntlmssp_sign_init(gensec_ntlmssp_state);
 354         if (!NT_STATUS_IS_OK(nt_status)) {
 355                 DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
 356                           nt_errstr(nt_status)));
 357                 return nt_status;
 358         }
 359
 360         return nt_status;
 361 }
 362
 363 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 364 {
 365         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 366         NTSTATUS nt_status;
 367
 368         nt_status = gensec_ntlmssp_start(gensec_security);
 369         NT_STATUS_NOT_OK_RETURN(nt_status);
 370
 371         gensec_ntlmssp_state = gensec_security->private_data;
 372
 373         gensec_ntlmssp_state->role = NTLMSSP_CLIENT;
 374
 375         gensec_ntlmssp_state->get_domain = lp_workgroup;
 376
 377         gensec_ntlmssp_state->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
 378
 379         gensec_ntlmssp_state->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
 380
 381         gensec_ntlmssp_state->allow_lm_key = (lp_lanman_auth()
 382                                           && lp_parm_bool(-1, "ntlmssp_client", "allow_lm_key", False));
 383
 384         gensec_ntlmssp_state->use_ntlmv2 = lp_client_ntlmv2_auth();
 385
 386         gensec_ntlmssp_state->expected_state = NTLMSSP_INITIAL;
 387
 388         gensec_ntlmssp_state->neg_flags =
 389                 NTLMSSP_NEGOTIATE_NTLM |
 390                 NTLMSSP_REQUEST_TARGET;
 391
 392         if (lp_parm_bool(-1, "ntlmssp_client", "128bit", True)) {
 393                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_128;
 394         }
 395
 396         if (lp_parm_bool(-1, "ntlmssp_client", "keyexchange", True)) {
 397                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 398         }
 399
 400         if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
 401                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 402         } else {
 403                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 404                 gensec_ntlmssp_state->use_ntlmv2 = False;
 405         }
 406
 407         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 408                 /*
 409                  * We need to set this to allow a later SetPassword
 410                  * via the SAMR pipe to succeed. Strange.... We could
 411                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 412                  *
 413                  * Without this, Windows will not create the master key
 414                  * that it thinks is only used for NTLMSSP signing and
 415                  * sealing.  (It is actually pulled out and used directly)
 416                  */
 417                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 418         }
 419         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 420                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 421         }
 422         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 423                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 424         }
 425
 426         gensec_security->private_data = gensec_ntlmssp_state;
 427
 428         return NT_STATUS_OK;
 429 }
 430