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 zero[1];
 181                 static const uint8_t zeros[16];
 182                 /* do nothing - blobs are zero length */
 183
 184                 /* session key is all zeros */
 185                 session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
 186                 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
 187
 188                 lm_response = data_blob_talloc(gensec_ntlmssp_state, zero, 1);
 189                 nt_response = data_blob(NULL, 0);
 190
 191                 /* not doing NLTM2 without a password */
 192                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 193         } else if (gensec_ntlmssp_state->use_ntlmv2) {
 194
 195                 if (!struct_blob.length) {
 196                         /* be lazy, match win2k - we can't do NTLMv2 without it */
 197                         DEBUG(1, ("Server did not provide 'target information', required for NTLMv2\n"));
 198                         return NT_STATUS_INVALID_PARAMETER;
 199                 }
 200
 201                 /* TODO: if the remote server is standalone, then we should replace 'domain'
 202                    with the server name as supplied above */
 203
 204                 if (!SMBNTLMv2encrypt(user,
 205                                       domain,
 206                                       password, &challenge_blob,
 207                                       &struct_blob,
 208                                       &lm_response, &nt_response,
 209                                       NULL, &session_key)) {
 210                         data_blob_free(&challenge_blob);
 211                         data_blob_free(&struct_blob);
 212                         return NT_STATUS_NO_MEMORY;
 213                 }
 214
 215                 /* LM Key is incompatible... */
 216                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 217
 218         } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 219                 struct MD5Context md5_session_nonce_ctx;
 220                 uint8_t nt_hash[16];
 221                 uint8_t session_nonce[16];
 222                 uint8_t session_nonce_hash[16];
 223                 uint8_t user_session_key[16];
 224                 E_md4hash(password, nt_hash);
 225
 226                 lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 227                 generate_random_buffer(lm_response.data, 8);
 228                 memset(lm_response.data+8, 0, 16);
 229
 230                 memcpy(session_nonce, challenge_blob.data, 8);
 231                 memcpy(&session_nonce[8], lm_response.data, 8);
 232
 233                 MD5Init(&md5_session_nonce_ctx);
 234                 MD5Update(&md5_session_nonce_ctx, challenge_blob.data, 8);
 235                 MD5Update(&md5_session_nonce_ctx, lm_response.data, 8);
 236                 MD5Final(session_nonce_hash, &md5_session_nonce_ctx);
 237
 238                 DEBUG(5, ("NTLMSSP challenge set by NTLM2\n"));
 239                 DEBUG(5, ("challenge is: \n"));
 240                 dump_data(5, session_nonce_hash, 8);
 241
 242                 nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 243                 SMBNTencrypt(password,
 244                              session_nonce_hash,
 245                              nt_response.data);
 246
 247                 session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 248
 249                 SMBsesskeygen_ntv1(nt_hash, user_session_key);
 250                 hmac_md5(user_session_key, session_nonce, sizeof(session_nonce), session_key.data);
 251                 dump_data_pw("NTLM2 session key:\n", session_key.data, session_key.length);
 252
 253                 /* LM Key is incompatible... */
 254                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 255         } else {
 256                 uint8_t nt_hash[16];
 257
 258                 if (gensec_ntlmssp_state->use_nt_response) {
 259                         nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 260                         SMBNTencrypt(password,challenge_blob.data,
 261                                      nt_response.data);
 262                         E_md4hash(password, nt_hash);
 263                         session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 264                         SMBsesskeygen_ntv1(nt_hash, session_key.data);
 265                         dump_data_pw("NT session key:\n", session_key.data, session_key.length);
 266                 }
 267
 268                 /* lanman auth is insecure, it may be disabled */
 269                 if (lp_client_lanman_auth()) {
 270                         lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 271                         if (!SMBencrypt(password,challenge_blob.data,
 272                                         lm_response.data)) {
 273                                 /* If the LM password was too long (and therefore the LM hash being
 274                                    of the first 14 chars only), don't send it */
 275                                 data_blob_free(&lm_response);
 276
 277                                 /* LM Key is incompatible with 'long' passwords */
 278                                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 279                         } else {
 280                                 E_deshash(password, lm_hash);
 281                                 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 282                                 memcpy(lm_session_key.data, lm_hash, 8);
 283                                 memset(&lm_session_key.data[8], '\0', 8);
 284
 285                                 if (!gensec_ntlmssp_state->use_nt_response) {
 286                                         session_key = lm_session_key;
 287                                 }
 288                         }
 289                 } else {
 290                         /* LM Key is incompatible... */
 291                         gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 292                 }
 293         }
 294
 295         if ((gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 296             && lp_client_lanman_auth() && lm_session_key.length == 16) {
 297                 DATA_BLOB new_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 298                 if (lm_response.length == 24) {
 299                         SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
 300                                                   new_session_key.data);
 301                 } else {
 302                         static const uint8_t zeros[24];
 303                         SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
 304                                                   new_session_key.data);
 305                 }
 306                 new_session_key.length = 16;
 307                 session_key = new_session_key;
 308                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 309         }
 310
 311
 312         /* Key exchange encryptes a new client-generated session key with
 313            the password-derived key */
 314         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 315                 /* Make up a new session key */
 316                 uint8_t client_session_key[16];
 317                 generate_random_buffer(client_session_key, sizeof(client_session_key));
 318
 319                 /* Encrypt the new session key with the old one */
 320                 encrypted_session_key = data_blob_talloc(gensec_ntlmssp_state,
 321                                                          client_session_key, sizeof(client_session_key));
 322                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 323                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 324                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 325
 326                 /* Mark the new session key as the 'real' session key */
 327                 session_key = data_blob_talloc(gensec_ntlmssp_state, client_session_key, sizeof(client_session_key));
 328         }
 329
 330         /* this generates the actual auth packet */
 331         if (!msrpc_gen(out_mem_ctx,
 332                        out, auth_gen_string,
 333                        "NTLMSSP",
 334                        NTLMSSP_AUTH,
 335                        lm_response.data, lm_response.length,
 336                        nt_response.data, nt_response.length,
 337                        domain,
 338                        user,
 339                        cli_credentials_get_workstation(gensec_security->credentials),
 340                        encrypted_session_key.data, encrypted_session_key.length,
 341                        gensec_ntlmssp_state->neg_flags)) {
 342
 343                 return NT_STATUS_NO_MEMORY;
 344         }
 345
 346         gensec_ntlmssp_state->session_key = session_key;
 347
 348         /* The client might be using 56 or 40 bit weakened keys */
 349         ntlmssp_weaken_keys(gensec_ntlmssp_state);
 350
 351         gensec_ntlmssp_state->chal = challenge_blob;
 352         gensec_ntlmssp_state->lm_resp = lm_response;
 353         gensec_ntlmssp_state->nt_resp = nt_response;
 354
 355         gensec_ntlmssp_state->expected_state = NTLMSSP_DONE;
 356
 357         nt_status = ntlmssp_sign_init(gensec_ntlmssp_state);
 358         if (!NT_STATUS_IS_OK(nt_status)) {
 359                 DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
 360                           nt_errstr(nt_status)));
 361                 return nt_status;
 362         }
 363
 364         return nt_status;
 365 }
 366
 367 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 368 {
 369         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 370         NTSTATUS nt_status;
 371
 372         nt_status = gensec_ntlmssp_start(gensec_security);
 373         NT_STATUS_NOT_OK_RETURN(nt_status);
 374
 375         gensec_ntlmssp_state = gensec_security->private_data;
 376
 377         gensec_ntlmssp_state->role = NTLMSSP_CLIENT;
 378
 379         gensec_ntlmssp_state->get_domain = lp_workgroup;
 380
 381         gensec_ntlmssp_state->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
 382
 383         gensec_ntlmssp_state->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
 384
 385         gensec_ntlmssp_state->allow_lm_key = (lp_lanman_auth()
 386                                           && lp_parm_bool(-1, "ntlmssp_client", "allow_lm_key", False));
 387
 388         gensec_ntlmssp_state->use_ntlmv2 = lp_client_ntlmv2_auth();
 389
 390         gensec_ntlmssp_state->expected_state = NTLMSSP_INITIAL;
 391
 392         gensec_ntlmssp_state->neg_flags =
 393                 NTLMSSP_NEGOTIATE_NTLM |
 394                 NTLMSSP_REQUEST_TARGET;
 395
 396         if (lp_parm_bool(-1, "ntlmssp_client", "128bit", True)) {
 397                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_128;
 398         }
 399
 400         if (lp_parm_bool(-1, "ntlmssp_client", "keyexchange", True)) {
 401                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 402         }
 403
 404         if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
 405                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 406         } else {
 407                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 408                 gensec_ntlmssp_state->use_ntlmv2 = False;
 409         }
 410
 411         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 412                 /*
 413                  * We need to set this to allow a later SetPassword
 414                  * via the SAMR pipe to succeed. Strange.... We could
 415                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 416                  *
 417                  * Without this, Windows will not create the master key
 418                  * that it thinks is only used for NTLMSSP signing and
 419                  * sealing.  (It is actually pulled out and used directly)
 420                  */
 421                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 422         }
 423         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 424                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 425         }
 426         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 427                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 428         }
 429
 430         gensec_security->private_data = gensec_ntlmssp_state;
 431
 432         return NT_STATUS_OK;
 433 }
 434