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 #include "librpc/gen_ndr/ndr_samr.h" /* for struct samrPassword */
  30
  31 /*********************************************************************
  32  Client side NTLMSSP
  33 *********************************************************************/
  34
  35 /**
  36  * Next state function for the Initial packet
  37  *
  38  * @param ntlmssp_state NTLMSSP State
  39  * @param out_mem_ctx The DATA_BLOB *out will be allocated on this context
  40  * @param in A NULL data blob (input ignored)
  41  * @param out The initial negotiate request to the server, as an talloc()ed DATA_BLOB, on out_mem_ctx
  42  * @return Errors or NT_STATUS_OK.
  43  */
  44
  45 NTSTATUS ntlmssp_client_initial(struct gensec_security *gensec_security,
  46                                 TALLOC_CTX *out_mem_ctx,
  47                                 DATA_BLOB in, DATA_BLOB *out)
  48 {
  49         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
  50
  51         if (gensec_ntlmssp_state->unicode) {
  52                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
  53         } else {
  54                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
  55         }
  56
  57         if (gensec_ntlmssp_state->use_ntlmv2) {
  58                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
  59         }
  60
  61         /* generate the ntlmssp negotiate packet */
  62         msrpc_gen(out_mem_ctx,
  63                   out, "CddAA",
  64                   "NTLMSSP",
  65                   NTLMSSP_NEGOTIATE,
  66                   gensec_ntlmssp_state->neg_flags,
  67                   gensec_ntlmssp_state->get_domain(),
  68                   cli_credentials_get_workstation(gensec_security->credentials));
  69
  70         gensec_ntlmssp_state->expected_state = NTLMSSP_CHALLENGE;
  71
  72         return NT_STATUS_MORE_PROCESSING_REQUIRED;
  73 }
  74
  75 /**
  76  * Next state function for the Challenge Packet.  Generate an auth packet.
  77  *
  78  * @param gensec_security GENSEC state
  79  * @param out_mem_ctx Memory context for *out
  80  * @param in The server challnege, as a DATA_BLOB.  reply.data must be NULL
  81  * @param out The next request (auth packet) to the server, as an allocated DATA_BLOB, on the out_mem_ctx context
  82  * @return Errors or NT_STATUS_OK.
  83  */
  84
  85 NTSTATUS ntlmssp_client_challenge(struct gensec_security *gensec_security,
  86                                   TALLOC_CTX *out_mem_ctx,
  87                                   const DATA_BLOB in, DATA_BLOB *out)
  88 {
  89         struct gensec_ntlmssp_state *gensec_ntlmssp_state = gensec_security->private_data;
  90         uint32_t chal_flags, ntlmssp_command, unkn1, unkn2;
  91         DATA_BLOB server_domain_blob;
  92         DATA_BLOB challenge_blob;
  93         DATA_BLOB struct_blob = data_blob(NULL, 0);
  94         char *server_domain;
  95         const char *chal_parse_string;
  96         const char *auth_gen_string;
  97         uint8_t lm_hash[16];
  98         DATA_BLOB lm_response = data_blob(NULL, 0);
  99         DATA_BLOB nt_response = data_blob(NULL, 0);
 100         DATA_BLOB session_key = data_blob(NULL, 0);
 101         DATA_BLOB lm_session_key = data_blob(NULL, 0);
 102         DATA_BLOB encrypted_session_key = data_blob(NULL, 0);
 103         NTSTATUS nt_status;
 104
 105         const struct samr_Password *nt_hash;
 106         const char *user, *domain, *password;
 107
 108         if (!msrpc_parse(out_mem_ctx,
 109                          &in, "CdBd",
 110                          "NTLMSSP",
 111                          &ntlmssp_command,
 112                          &server_domain_blob,
 113                          &chal_flags)) {
 114                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
 115                 dump_data(2, in.data, in.length);
 116
 117                 return NT_STATUS_INVALID_PARAMETER;
 118         }
 119
 120         data_blob_free(&server_domain_blob);
 121
 122         DEBUG(3, ("Got challenge flags:\n"));
 123         debug_ntlmssp_flags(chal_flags);
 124
 125         ntlmssp_handle_neg_flags(gensec_ntlmssp_state, chal_flags, gensec_ntlmssp_state->allow_lm_key);
 126
 127         if (gensec_ntlmssp_state->unicode) {
 128                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 129                         chal_parse_string = "CdUdbddB";
 130                 } else {
 131                         chal_parse_string = "CdUdbdd";
 132                 }
 133                 auth_gen_string = "CdBBUUUBd";
 134         } else {
 135                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 136                         chal_parse_string = "CdAdbddB";
 137                 } else {
 138                         chal_parse_string = "CdAdbdd";
 139                 }
 140
 141                 auth_gen_string = "CdBBAAABd";
 142         }
 143
 144         DEBUG(3, ("NTLMSSP: Set final flags:\n"));
 145         debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags);
 146
 147         if (!msrpc_parse(out_mem_ctx,
 148                          &in, chal_parse_string,
 149                          "NTLMSSP",
 150                          &ntlmssp_command,
 151                          &server_domain,
 152                          &chal_flags,
 153                          &challenge_blob, 8,
 154                          &unkn1, &unkn2,
 155                          &struct_blob)) {
 156                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
 157                 dump_data(2, in.data, in.length);
 158                 return NT_STATUS_INVALID_PARAMETER;
 159         }
 160
 161         gensec_ntlmssp_state->server_domain = server_domain;
 162
 163         if (challenge_blob.length != 8) {
 164                 return NT_STATUS_INVALID_PARAMETER;
 165         }
 166
 167         /* Correctly handle username in the original form of user@REALM, which is valid */
 168         if (gensec_security->credentials->realm_obtained
 169             > gensec_security->credentials->domain_obtained) {
 170                 user = talloc_asprintf(out_mem_ctx, "%s@%s",
 171                                        cli_credentials_get_username(gensec_security->credentials),
 172                                        cli_credentials_get_realm(gensec_security->credentials));
 173                 domain = NULL;
 174         } else {
 175                 user = cli_credentials_get_username(gensec_security->credentials);
 176                 domain = cli_credentials_get_domain(gensec_security->credentials);
 177         }
 178
 179         nt_hash = cli_credentials_get_nt_hash(gensec_security->credentials, out_mem_ctx);
 180         password = cli_credentials_get_password(gensec_security->credentials);
 181
 182         if (!nt_hash) {
 183                 static const uint8_t zeros[16];
 184                 /* do nothing - blobs are zero length */
 185
 186                 /* session key is all zeros */
 187                 session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
 188                 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, zeros, 16);
 189
 190                 lm_response = data_blob(NULL, 0);
 191                 nt_response = data_blob(NULL, 0);
 192
 193                 /* not doing NLTM2 without a password */
 194                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 195         } else if (gensec_ntlmssp_state->use_ntlmv2) {
 196
 197                 if (!struct_blob.length) {
 198                         /* be lazy, match win2k - we can't do NTLMv2 without it */
 199                         DEBUG(1, ("Server did not provide 'target information', required for NTLMv2\n"));
 200                         return NT_STATUS_INVALID_PARAMETER;
 201                 }
 202
 203                 /* TODO: if the remote server is standalone, then we should replace 'domain'
 204                    with the server name as supplied above */
 205
 206                 if (!SMBNTLMv2encrypt_hash(gensec_ntlmssp_state,
 207                                            user,
 208                                            domain,
 209                                            nt_hash->hash, &challenge_blob,
 210                                            &struct_blob,
 211                                            &lm_response, &nt_response,
 212                                            NULL, &session_key)) {
 213                         data_blob_free(&challenge_blob);
 214                         data_blob_free(&struct_blob);
 215                         return NT_STATUS_NO_MEMORY;
 216                 }
 217
 218                 /* LM Key is incompatible... */
 219                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 220
 221         } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 222                 struct MD5Context md5_session_nonce_ctx;
 223                 uint8_t session_nonce[16];
 224                 uint8_t session_nonce_hash[16];
 225                 uint8_t user_session_key[16];
 226
 227                 lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 228                 generate_random_buffer(lm_response.data, 8);
 229                 memset(lm_response.data+8, 0, 16);
 230
 231                 memcpy(session_nonce, challenge_blob.data, 8);
 232                 memcpy(&session_nonce[8], lm_response.data, 8);
 233
 234                 MD5Init(&md5_session_nonce_ctx);
 235                 MD5Update(&md5_session_nonce_ctx, challenge_blob.data, 8);
 236                 MD5Update(&md5_session_nonce_ctx, lm_response.data, 8);
 237                 MD5Final(session_nonce_hash, &md5_session_nonce_ctx);
 238
 239                 DEBUG(5, ("NTLMSSP challenge set by NTLM2\n"));
 240                 DEBUG(5, ("challenge is: \n"));
 241                 dump_data(5, session_nonce_hash, 8);
 242
 243                 nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 244                 SMBOWFencrypt(nt_hash->hash,
 245                               session_nonce_hash,
 246                               nt_response.data);
 247
 248                 session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 249
 250                 SMBsesskeygen_ntv1(nt_hash->hash, user_session_key);
 251                 hmac_md5(user_session_key, session_nonce, sizeof(session_nonce), session_key.data);
 252                 dump_data_pw("NTLM2 session key:\n", session_key.data, session_key.length);
 253
 254                 /* LM Key is incompatible... */
 255                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 256         } else {
 257                 if (gensec_ntlmssp_state->use_nt_response) {
 258                         nt_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 259                         SMBOWFencrypt(nt_hash->hash, challenge_blob.data,
 260                                       nt_response.data);
 261
 262                         session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 263                         SMBsesskeygen_ntv1(nt_hash->hash, session_key.data);
 264                         dump_data_pw("NT session key:\n", session_key.data, session_key.length);
 265                 }
 266
 267                 /* lanman auth is insecure, it may be disabled.  We may also not have a password */
 268                 if (lp_client_lanman_auth() && password) {
 269                         lm_response = data_blob_talloc(gensec_ntlmssp_state, NULL, 24);
 270                         if (!SMBencrypt(password,challenge_blob.data,
 271                                         lm_response.data)) {
 272                                 /* If the LM password was too long (and therefore the LM hash being
 273                                    of the first 14 chars only), don't send it */
 274                                 data_blob_free(&lm_response);
 275
 276                                 /* LM Key is incompatible with 'long' passwords */
 277                                 gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 278                         } else {
 279                                 E_deshash(password, lm_hash);
 280                                 lm_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 281                                 memcpy(lm_session_key.data, lm_hash, 8);
 282                                 memset(&lm_session_key.data[8], '\0', 8);
 283
 284                                 if (!gensec_ntlmssp_state->use_nt_response) {
 285                                         session_key = lm_session_key;
 286                                 }
 287                         }
 288                 } else {
 289                         /* LM Key is incompatible... */
 290                         gensec_ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 291                 }
 292         }
 293
 294         if ((gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 295             && lp_client_lanman_auth() && lm_session_key.length == 16) {
 296                 DATA_BLOB new_session_key = data_blob_talloc(gensec_ntlmssp_state, NULL, 16);
 297                 if (lm_response.length == 24) {
 298                         SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
 299                                                   new_session_key.data);
 300                 } else {
 301                         static const uint8_t zeros[24];
 302                         SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
 303                                                   new_session_key.data);
 304                 }
 305                 new_session_key.length = 16;
 306                 session_key = new_session_key;
 307                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 308         }
 309
 310
 311         /* Key exchange encryptes a new client-generated session key with
 312            the password-derived key */
 313         if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 314                 /* Make up a new session key */
 315                 uint8_t client_session_key[16];
 316                 generate_random_buffer(client_session_key, sizeof(client_session_key));
 317
 318                 /* Encrypt the new session key with the old one */
 319                 encrypted_session_key = data_blob_talloc(gensec_ntlmssp_state,
 320                                                          client_session_key, sizeof(client_session_key));
 321                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 322                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 323                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 324
 325                 /* Mark the new session key as the 'real' session key */
 326                 session_key = data_blob_talloc(gensec_ntlmssp_state, client_session_key, sizeof(client_session_key));
 327         }
 328
 329         /* this generates the actual auth packet */
 330         if (!msrpc_gen(out_mem_ctx,
 331                        out, auth_gen_string,
 332                        "NTLMSSP",
 333                        NTLMSSP_AUTH,
 334                        lm_response.data, lm_response.length,
 335                        nt_response.data, nt_response.length,
 336                        domain,
 337                        user,
 338                        cli_credentials_get_workstation(gensec_security->credentials),
 339                        encrypted_session_key.data, encrypted_session_key.length,
 340                        gensec_ntlmssp_state->neg_flags)) {
 341
 342                 return NT_STATUS_NO_MEMORY;
 343         }
 344
 345         gensec_ntlmssp_state->session_key = session_key;
 346
 347         /* The client might be using 56 or 40 bit weakened keys */
 348         ntlmssp_weaken_keys(gensec_ntlmssp_state);
 349
 350         gensec_ntlmssp_state->chal = challenge_blob;
 351         gensec_ntlmssp_state->lm_resp = lm_response;
 352         gensec_ntlmssp_state->nt_resp = nt_response;
 353
 354         gensec_ntlmssp_state->expected_state = NTLMSSP_DONE;
 355
 356         if (gensec_security->want_features & GENSEC_FEATURE_SIGN|GENSEC_FEATURE_SEAL) {
 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
 365         return nt_status;
 366 }
 367
 368 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 369 {
 370         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 371         NTSTATUS nt_status;
 372
 373         nt_status = gensec_ntlmssp_start(gensec_security);
 374         NT_STATUS_NOT_OK_RETURN(nt_status);
 375
 376         gensec_ntlmssp_state = gensec_security->private_data;
 377
 378         gensec_ntlmssp_state->role = NTLMSSP_CLIENT;
 379
 380         gensec_ntlmssp_state->get_domain = lp_workgroup;
 381
 382         gensec_ntlmssp_state->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
 383
 384         gensec_ntlmssp_state->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
 385
 386         gensec_ntlmssp_state->allow_lm_key = (lp_lanman_auth()
 387                                           && lp_parm_bool(-1, "ntlmssp_client", "allow_lm_key", False));
 388
 389         gensec_ntlmssp_state->use_ntlmv2 = lp_client_ntlmv2_auth();
 390
 391         gensec_ntlmssp_state->expected_state = NTLMSSP_INITIAL;
 392
 393         gensec_ntlmssp_state->neg_flags =
 394                 NTLMSSP_NEGOTIATE_NTLM |
 395                 NTLMSSP_REQUEST_TARGET;
 396
 397         if (lp_parm_bool(-1, "ntlmssp_client", "128bit", True)) {
 398                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_128;
 399         }
 400
 401         if (lp_parm_bool(-1, "ntlmssp_client", "keyexchange", True)) {
 402                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 403         }
 404
 405         if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
 406                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 407         } else {
 408                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 409                 gensec_ntlmssp_state->use_ntlmv2 = False;
 410         }
 411
 412         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 413                 /*
 414                  * We need to set this to allow a later SetPassword
 415                  * via the SAMR pipe to succeed. Strange.... We could
 416                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 417                  *
 418                  * Without this, Windows will not create the master key
 419                  * that it thinks is only used for NTLMSSP signing and
 420                  * sealing.  (It is actually pulled out and used directly)
 421                  */
 422                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 423         }
 424         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 425                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 426         }
 427         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 428                 gensec_ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 429         }
 430
 431         gensec_security->private_data = gensec_ntlmssp_state;
 432
 433         return NT_STATUS_OK;
 434 }
 435