source/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 The request, as a DATA_BLOB.  reply.data must be NULL
  40  * @param out The reply, 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         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp_state->ntlmssp_state;
  50
  51         if (ntlmssp_state->unicode) {
  52                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
  53         } else {
  54                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
  55         }
  56
  57         if (ntlmssp_state->use_ntlmv2) {
  58                 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                   ntlmssp_state->neg_flags,
  67                   ntlmssp_state->get_domain(),
  68                   cli_credentials_get_workstation(gensec_security->credentials));
  69
  70         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 ntlmssp_state NTLMSSP State
  79  * @param request The request, as a DATA_BLOB.  reply.data must be NULL
  80  * @param request The reply, as an allocated DATA_BLOB, caller to free.
  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         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp_state->ntlmssp_state;
  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 char *user, *domain, *password;
 106
 107         if (!msrpc_parse(ntlmssp_state,
 108                          &in, "CdBd",
 109                          "NTLMSSP",
 110                          &ntlmssp_command,
 111                          &server_domain_blob,
 112                          &chal_flags)) {
 113                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
 114                 dump_data(2, in.data, in.length);
 115
 116                 return NT_STATUS_INVALID_PARAMETER;
 117         }
 118
 119         data_blob_free(&server_domain_blob);
 120
 121         DEBUG(3, ("Got challenge flags:\n"));
 122         debug_ntlmssp_flags(chal_flags);
 123
 124         ntlmssp_handle_neg_flags(ntlmssp_state, chal_flags, ntlmssp_state->allow_lm_key);
 125
 126         if (ntlmssp_state->unicode) {
 127                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 128                         chal_parse_string = "CdUdbddB";
 129                 } else {
 130                         chal_parse_string = "CdUdbdd";
 131                 }
 132                 auth_gen_string = "CdBBUUUBd";
 133         } else {
 134                 if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
 135                         chal_parse_string = "CdAdbddB";
 136                 } else {
 137                         chal_parse_string = "CdAdbdd";
 138                 }
 139
 140                 auth_gen_string = "CdBBAAABd";
 141         }
 142
 143         DEBUG(3, ("NTLMSSP: Set final flags:\n"));
 144         debug_ntlmssp_flags(ntlmssp_state->neg_flags);
 145
 146         if (!msrpc_parse(ntlmssp_state,
 147                          &in, chal_parse_string,
 148                          "NTLMSSP",
 149                          &ntlmssp_command,
 150                          &server_domain,
 151                          &chal_flags,
 152                          &challenge_blob, 8,
 153                          &unkn1, &unkn2,
 154                          &struct_blob)) {
 155                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
 156                 dump_data(2, in.data, in.length);
 157                 return NT_STATUS_INVALID_PARAMETER;
 158         }
 159
 160         ntlmssp_state->server_domain = server_domain;
 161
 162         if (challenge_blob.length != 8) {
 163                 return NT_STATUS_INVALID_PARAMETER;
 164         }
 165
 166         /* Correctly handle username in the original form of user@REALM, which is valid */
 167         if (gensec_security->credentials->realm_obtained
 168             > gensec_security->credentials->domain_obtained) {
 169                 user = talloc_asprintf(out_mem_ctx, "%s@%s",
 170                                        cli_credentials_get_username(gensec_security->credentials),
 171                                        cli_credentials_get_realm(gensec_security->credentials));
 172                 domain = NULL;
 173         } else {
 174                 user = cli_credentials_get_username(gensec_security->credentials);
 175                 domain = cli_credentials_get_domain(gensec_security->credentials);
 176         }
 177
 178         password = cli_credentials_get_password(gensec_security->credentials);
 179
 180         if (!password) {
 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(ntlmssp_state, zeros, 16);
 186                 lm_session_key = data_blob_talloc(ntlmssp_state, zeros, 16);
 187
 188                 /* not doing NLTM2 without a password */
 189                 ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 190         } else if (ntlmssp_state->use_ntlmv2) {
 191
 192                 if (!struct_blob.length) {
 193                         /* be lazy, match win2k - we can't do NTLMv2 without it */
 194                         DEBUG(1, ("Server did not provide 'target information', required for NTLMv2\n"));
 195                         return NT_STATUS_INVALID_PARAMETER;
 196                 }
 197
 198                 /* TODO: if the remote server is standalone, then we should replace 'domain'
 199                    with the server name as supplied above */
 200
 201                 if (!SMBNTLMv2encrypt(user,
 202                                       domain,
 203                                       password, &challenge_blob,
 204                                       &struct_blob,
 205                                       &lm_response, &nt_response,
 206                                       NULL, &session_key)) {
 207                         data_blob_free(&challenge_blob);
 208                         data_blob_free(&struct_blob);
 209                         return NT_STATUS_NO_MEMORY;
 210                 }
 211
 212                 /* LM Key is incompatible... */
 213                 ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 214
 215         } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 216                 struct MD5Context md5_session_nonce_ctx;
 217                 uint8_t nt_hash[16];
 218                 uint8_t session_nonce[16];
 219                 uint8_t session_nonce_hash[16];
 220                 uint8_t user_session_key[16];
 221                 E_md4hash(password, nt_hash);
 222
 223                 lm_response = data_blob_talloc(ntlmssp_state, NULL, 24);
 224                 generate_random_buffer(lm_response.data, 8);
 225                 memset(lm_response.data+8, 0, 16);
 226
 227                 memcpy(session_nonce, challenge_blob.data, 8);
 228                 memcpy(&session_nonce[8], lm_response.data, 8);
 229
 230                 MD5Init(&md5_session_nonce_ctx);
 231                 MD5Update(&md5_session_nonce_ctx, challenge_blob.data, 8);
 232                 MD5Update(&md5_session_nonce_ctx, lm_response.data, 8);
 233                 MD5Final(session_nonce_hash, &md5_session_nonce_ctx);
 234
 235                 DEBUG(5, ("NTLMSSP challenge set by NTLM2\n"));
 236                 DEBUG(5, ("challenge is: \n"));
 237                 dump_data(5, session_nonce_hash, 8);
 238
 239                 nt_response = data_blob_talloc(ntlmssp_state, NULL, 24);
 240                 SMBNTencrypt(password,
 241                              session_nonce_hash,
 242                              nt_response.data);
 243
 244                 session_key = data_blob_talloc(ntlmssp_state, NULL, 16);
 245
 246                 SMBsesskeygen_ntv1(nt_hash, user_session_key);
 247                 hmac_md5(user_session_key, session_nonce, sizeof(session_nonce), session_key.data);
 248                 dump_data_pw("NTLM2 session key:\n", session_key.data, session_key.length);
 249
 250                 /* LM Key is incompatible... */
 251                 ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 252         } else {
 253                 uint8_t nt_hash[16];
 254
 255                 if (ntlmssp_state->use_nt_response) {
 256                         nt_response = data_blob_talloc(ntlmssp_state, NULL, 24);
 257                         SMBNTencrypt(password,challenge_blob.data,
 258                                      nt_response.data);
 259                         E_md4hash(password, nt_hash);
 260                         session_key = data_blob_talloc(ntlmssp_state, NULL, 16);
 261                         SMBsesskeygen_ntv1(nt_hash, session_key.data);
 262                         dump_data_pw("NT session key:\n", session_key.data, session_key.length);
 263                 }
 264
 265                 /* lanman auth is insecure, it may be disabled */
 266                 if (lp_client_lanman_auth()) {
 267                         lm_response = data_blob_talloc(ntlmssp_state, NULL, 24);
 268                         if (!SMBencrypt(password,challenge_blob.data,
 269                                         lm_response.data)) {
 270                                 /* If the LM password was too long (and therefore the LM hash being
 271                                    of the first 14 chars only), don't send it */
 272                                 data_blob_free(&lm_response);
 273
 274                                 /* LM Key is incompatible with 'long' passwords */
 275                                 ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 276                         } else {
 277                                 E_deshash(password, lm_hash);
 278                                 lm_session_key = data_blob_talloc(ntlmssp_state, NULL, 16);
 279                                 memcpy(lm_session_key.data, lm_hash, 8);
 280                                 memset(&lm_session_key.data[8], '\0', 8);
 281
 282                                 if (!ntlmssp_state->use_nt_response) {
 283                                         session_key = lm_session_key;
 284                                 }
 285                         }
 286                 } else {
 287                         /* LM Key is incompatible... */
 288                         ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 289                 }
 290         }
 291
 292         if ((ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 293             && lp_client_lanman_auth() && lm_session_key.length == 16) {
 294                 DATA_BLOB new_session_key = data_blob_talloc(ntlmssp_state, NULL, 16);
 295                 if (lm_response.length == 24) {
 296                         SMBsesskeygen_lm_sess_key(lm_session_key.data, lm_response.data,
 297                                                   new_session_key.data);
 298                 } else {
 299                         static const uint8_t zeros[24];
 300                         SMBsesskeygen_lm_sess_key(lm_session_key.data, zeros,
 301                                                   new_session_key.data);
 302                 }
 303                 new_session_key.length = 16;
 304                 session_key = new_session_key;
 305                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 306         }
 307
 308
 309         /* Key exchange encryptes a new client-generated session key with
 310            the password-derived key */
 311         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 312                 /* Make up a new session key */
 313                 uint8_t client_session_key[16];
 314                 generate_random_buffer(client_session_key, sizeof(client_session_key));
 315
 316                 /* Encrypt the new session key with the old one */
 317                 encrypted_session_key = data_blob_talloc(ntlmssp_state,
 318                                                          client_session_key, sizeof(client_session_key));
 319                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 320                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 321                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 322
 323                 /* Mark the new session key as the 'real' session key */
 324                 session_key = data_blob_talloc(ntlmssp_state, client_session_key, sizeof(client_session_key));
 325         }
 326
 327         /* this generates the actual auth packet */
 328         if (!msrpc_gen(out_mem_ctx,
 329                        out, auth_gen_string,
 330                        "NTLMSSP",
 331                        NTLMSSP_AUTH,
 332                        lm_response.data, lm_response.length,
 333                        nt_response.data, nt_response.length,
 334                        domain,
 335                        user,
 336                        cli_credentials_get_workstation(gensec_security->credentials),
 337                        encrypted_session_key.data, encrypted_session_key.length,
 338                        ntlmssp_state->neg_flags)) {
 339
 340                 return NT_STATUS_NO_MEMORY;
 341         }
 342
 343         ntlmssp_state->session_key = session_key;
 344
 345         /* The client might be using 56 or 40 bit weakened keys */
 346         ntlmssp_weaken_keys(ntlmssp_state);
 347
 348         ntlmssp_state->chal = challenge_blob;
 349         ntlmssp_state->lm_resp = lm_response;
 350         ntlmssp_state->nt_resp = nt_response;
 351
 352         ntlmssp_state->expected_state = NTLMSSP_DONE;
 353
 354         nt_status = ntlmssp_sign_init(ntlmssp_state);
 355         if (!NT_STATUS_IS_OK(nt_status)) {
 356                 DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
 357                           nt_errstr(nt_status)));
 358                 return nt_status;
 359         }
 360
 361         return nt_status;
 362 }
 363
 364 static NTSTATUS ntlmssp_client_start(TALLOC_CTX *mem_ctx, struct ntlmssp_state **ntlmssp_state)
 365 {
 366         *ntlmssp_state = talloc(mem_ctx, struct ntlmssp_state);
 367         if (!*ntlmssp_state) {
 368                 DEBUG(0,("ntlmssp_client_start: talloc failed!\n"));
 369                 return NT_STATUS_NO_MEMORY;
 370         }
 371         ZERO_STRUCTP(*ntlmssp_state);
 372
 373         (*ntlmssp_state)->role = NTLMSSP_CLIENT;
 374
 375         (*ntlmssp_state)->get_domain = lp_workgroup;
 376
 377         (*ntlmssp_state)->unicode = lp_parm_bool(-1, "ntlmssp_client", "unicode", True);
 378
 379         (*ntlmssp_state)->use_nt_response = lp_parm_bool(-1, "ntlmssp_client", "send_nt_reponse", True);
 380
 381         (*ntlmssp_state)->allow_lm_key = (lp_lanman_auth()
 382                                           && lp_parm_bool(-1, "ntlmssp_client", "allow_lm_key", False));
 383
 384         (*ntlmssp_state)->use_ntlmv2 = lp_client_ntlmv2_auth();
 385
 386         (*ntlmssp_state)->expected_state = NTLMSSP_INITIAL;
 387
 388         (*ntlmssp_state)->neg_flags =
 389                 NTLMSSP_NEGOTIATE_NTLM |
 390                 NTLMSSP_REQUEST_TARGET;
 391
 392         if (lp_parm_bool(-1, "ntlmssp_client", "128bit", True)) {
 393                 (*ntlmssp_state)->neg_flags |= NTLMSSP_NEGOTIATE_128;
 394         }
 395
 396         if (lp_parm_bool(-1, "ntlmssp_client", "keyexchange", True)) {
 397                 (*ntlmssp_state)->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 398         }
 399
 400         if (lp_parm_bool(-1, "ntlmssp_client", "ntlm2", True)) {
 401                 (*ntlmssp_state)->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 402         } else {
 403                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 404                 (*ntlmssp_state)->use_ntlmv2 = False;
 405         }
 406
 407         return NT_STATUS_OK;
 408 }
 409
 410 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 411 {
 412         struct gensec_ntlmssp_state *gensec_ntlmssp_state;
 413         NTSTATUS nt_status;
 414
 415         nt_status = gensec_ntlmssp_start(gensec_security);
 416         NT_STATUS_NOT_OK_RETURN(nt_status);
 417
 418         gensec_ntlmssp_state = gensec_security->private_data;
 419         nt_status = ntlmssp_client_start(gensec_ntlmssp_state,
 420                                          &gensec_ntlmssp_state->ntlmssp_state);
 421         NT_STATUS_NOT_OK_RETURN(nt_status);
 422
 423         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 424                 /*
 425                  * We need to set this to allow a later SetPassword
 426                  * via the SAMR pipe to succeed. Strange.... We could
 427                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 428                  *
 429                  * Without this, Windows will not create the master key
 430                  * that it thinks is only used for NTLMSSP signing and
 431                  * sealing.  (It is actually pulled out and used directly)
 432                  */
 433                 gensec_ntlmssp_state->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 434         }
 435         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 436                 gensec_ntlmssp_state->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 437         }
 438         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 439                 gensec_ntlmssp_state->ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 440         }
 441
 442         gensec_security->private_data = gensec_ntlmssp_state;
 443
 444         return NT_STATUS_OK;
 445 }
 446