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 3 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, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 struct auth_session_info;
  25
  26 #include "includes.h"
  27 #include "auth/ntlmssp/ntlmssp.h"
  28 #include "../lib/crypto/crypto.h"
  29 #include "../libcli/auth/libcli_auth.h"
  30 #include "auth/credentials/credentials.h"
  31 #include "auth/gensec/gensec.h"
  32 #include "auth/gensec/gensec_internal.h"
  33 #include "param/param.h"
  34 #include "auth/ntlmssp/ntlmssp_private.h"
  35 #include "../librpc/gen_ndr/ndr_ntlmssp.h"
  36 #include "../auth/ntlmssp/ntlmssp_ndr.h"
  37
  38 /*********************************************************************
  39  Client side NTLMSSP
  40 *********************************************************************/
  41
  42 /**
  43  * Next state function for the Initial packet
  44  *
  45  * @param ntlmssp_state NTLMSSP State
  46  * @param out_mem_ctx The DATA_BLOB *out will be allocated on this context
  47  * @param in A NULL data blob (input ignored)
  48  * @param out The initial negotiate request to the server, as an talloc()ed DATA_BLOB, on out_mem_ctx
  49  * @return Errors or NT_STATUS_OK.
  50  */
  51
  52 NTSTATUS ntlmssp_client_initial(struct gensec_security *gensec_security,
  53                                 TALLOC_CTX *out_mem_ctx,
  54                                 DATA_BLOB in, DATA_BLOB *out)
  55 {
  56         struct gensec_ntlmssp_context *gensec_ntlmssp =
  57                 talloc_get_type_abort(gensec_security->private_data,
  58                                       struct gensec_ntlmssp_context);
  59         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp->ntlmssp_state;
  60         const char *domain = ntlmssp_state->client.netbios_domain;
  61         const char *workstation = ntlmssp_state->client.netbios_name;
  62         NTSTATUS status;
  63
  64         /* These don't really matter in the initial packet, so don't panic if they are not set */
  65         if (!domain) {
  66                 domain = "";
  67         }
  68
  69         if (!workstation) {
  70                 workstation = "";
  71         }
  72
  73         if (ntlmssp_state->unicode) {
  74                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
  75         } else {
  76                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_OEM;
  77         }
  78
  79         if (ntlmssp_state->use_ntlmv2) {
  80                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
  81         }
  82
  83         /* generate the ntlmssp negotiate packet */
  84         status = msrpc_gen(out_mem_ctx,
  85                   out, "CddAA",
  86                   "NTLMSSP",
  87                   NTLMSSP_NEGOTIATE,
  88                   ntlmssp_state->neg_flags,
  89                   domain,
  90                   workstation);
  91
  92         if (!NT_STATUS_IS_OK(status)) {
  93                 DEBUG(0, ("ntlmssp_client_initial: failed to generate "
  94                           "ntlmssp negotiate packet\n"));
  95                 return status;
  96         }
  97
  98         if (DEBUGLEVEL >= 10) {
  99                 struct NEGOTIATE_MESSAGE *negotiate = talloc(
 100                         ntlmssp_state, struct NEGOTIATE_MESSAGE);
 101                 if (negotiate != NULL) {
 102                         status = ntlmssp_pull_NEGOTIATE_MESSAGE(
 103                                 out, negotiate, negotiate);
 104                         if (NT_STATUS_IS_OK(status)) {
 105                                 NDR_PRINT_DEBUG(NEGOTIATE_MESSAGE,
 106                                                 negotiate);
 107                         }
 108                         TALLOC_FREE(negotiate);
 109                 }
 110         }
 111
 112         ntlmssp_state->expected_state = NTLMSSP_CHALLENGE;
 113
 114         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 115 }
 116
 117 /**
 118  * Next state function for the Challenge Packet.  Generate an auth packet.
 119  *
 120  * @param gensec_security GENSEC state
 121  * @param out_mem_ctx Memory context for *out
 122  * @param in The server challnege, as a DATA_BLOB.  reply.data must be NULL
 123  * @param out The next request (auth packet) to the server, as an allocated DATA_BLOB, on the out_mem_ctx context
 124  * @return Errors or NT_STATUS_OK.
 125  */
 126
 127 NTSTATUS ntlmssp_client_challenge(struct gensec_security *gensec_security,
 128                                   TALLOC_CTX *out_mem_ctx,
 129                                   const DATA_BLOB in, DATA_BLOB *out)
 130 {
 131         struct gensec_ntlmssp_context *gensec_ntlmssp =
 132                 talloc_get_type_abort(gensec_security->private_data,
 133                                       struct gensec_ntlmssp_context);
 134         struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp->ntlmssp_state;
 135         uint32_t chal_flags, ntlmssp_command, unkn1 = 0, unkn2 = 0;
 136         DATA_BLOB server_domain_blob;
 137         DATA_BLOB challenge_blob;
 138         DATA_BLOB target_info = data_blob(NULL, 0);
 139         char *server_domain;
 140         const char *chal_parse_string;
 141         const char *chal_parse_string_short = NULL;
 142         const char *auth_gen_string;
 143         DATA_BLOB lm_response = data_blob(NULL, 0);
 144         DATA_BLOB nt_response = data_blob(NULL, 0);
 145         DATA_BLOB session_key = data_blob(NULL, 0);
 146         DATA_BLOB lm_session_key = data_blob(NULL, 0);
 147         DATA_BLOB encrypted_session_key = data_blob(NULL, 0);
 148         NTSTATUS nt_status;
 149         int flags = 0;
 150         const char *user, *domain;
 151
 152         TALLOC_CTX *mem_ctx = talloc_new(out_mem_ctx);
 153         if (!mem_ctx) {
 154                 return NT_STATUS_NO_MEMORY;
 155         }
 156
 157         if (!msrpc_parse(mem_ctx,
 158                          &in, "CdBd",
 159                          "NTLMSSP",
 160                          &ntlmssp_command,
 161                          &server_domain_blob,
 162                          &chal_flags)) {
 163                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
 164                 dump_data(2, in.data, in.length);
 165                 talloc_free(mem_ctx);
 166
 167                 return NT_STATUS_INVALID_PARAMETER;
 168         }
 169
 170         data_blob_free(&server_domain_blob);
 171
 172         DEBUG(3, ("Got challenge flags:\n"));
 173         debug_ntlmssp_flags(chal_flags);
 174
 175         ntlmssp_handle_neg_flags(ntlmssp_state, chal_flags, ntlmssp_state->allow_lm_key);
 176
 177         if (ntlmssp_state->unicode) {
 178                 if (chal_flags & NTLMSSP_NEGOTIATE_TARGET_INFO) {
 179                         chal_parse_string = "CdUdbddB";
 180                 } else {
 181                         chal_parse_string = "CdUdbdd";
 182                         chal_parse_string_short = "CdUdb";
 183                 }
 184                 auth_gen_string = "CdBBUUUBd";
 185         } else {
 186                 if (chal_flags & NTLMSSP_NEGOTIATE_TARGET_INFO) {
 187                         chal_parse_string = "CdAdbddB";
 188                 } else {
 189                         chal_parse_string = "CdAdbdd";
 190                         chal_parse_string_short = "CdAdb";
 191                 }
 192
 193                 auth_gen_string = "CdBBAAABd";
 194         }
 195
 196         if (!msrpc_parse(mem_ctx,
 197                          &in, chal_parse_string,
 198                          "NTLMSSP",
 199                          &ntlmssp_command,
 200                          &server_domain,
 201                          &chal_flags,
 202                          &challenge_blob, 8,
 203                          &unkn1, &unkn2,
 204                          &target_info)) {
 205
 206                 bool ok = false;
 207
 208                 DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
 209
 210                 if (chal_parse_string_short != NULL) {
 211                         /*
 212                          * In the case where NTLMSSP_NEGOTIATE_TARGET_INFO
 213                          * is not used, some NTLMSSP servers don't return
 214                          * the unused unkn1 and unkn2 fields.
 215                          * See bug:
 216                          * https://bugzilla.samba.org/show_bug.cgi?id=10016
 217                          * for packet traces.
 218                          * Try and parse again without them.
 219                          */
 220                         ok = msrpc_parse(mem_ctx,
 221                                 &in, chal_parse_string_short,
 222                                 "NTLMSSP",
 223                                 &ntlmssp_command,
 224                                 &server_domain,
 225                                 &chal_flags,
 226                                 &challenge_blob, 8);
 227                         if (!ok) {
 228                                 DEBUG(1, ("Failed to short parse "
 229                                         "the NTLMSSP Challenge: (#2)\n"));
 230                         }
 231                 }
 232
 233                 if (!ok) {
 234                         dump_data(2, in.data, in.length);
 235                         talloc_free(mem_ctx);
 236                         return NT_STATUS_INVALID_PARAMETER;
 237                 }
 238         }
 239
 240         if (chal_flags & NTLMSSP_TARGET_TYPE_SERVER) {
 241                 ntlmssp_state->server.is_standalone = true;
 242         } else {
 243                 ntlmssp_state->server.is_standalone = false;
 244         }
 245         /* TODO: parse struct_blob and fill in the rest */
 246         ntlmssp_state->server.netbios_name = "";
 247         ntlmssp_state->server.netbios_domain = server_domain;
 248         ntlmssp_state->server.dns_name = "";
 249         ntlmssp_state->server.dns_domain = "";
 250
 251         if (challenge_blob.length != 8) {
 252                 talloc_free(mem_ctx);
 253                 return NT_STATUS_INVALID_PARAMETER;
 254         }
 255
 256         cli_credentials_get_ntlm_username_domain(gensec_security->credentials, mem_ctx,
 257                                                  &user, &domain);
 258
 259         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
 260                 flags |= CLI_CRED_NTLM2;
 261         }
 262         if (ntlmssp_state->use_ntlmv2) {
 263                 flags |= CLI_CRED_NTLMv2_AUTH;
 264         }
 265         if (ntlmssp_state->use_nt_response) {
 266                 flags |= CLI_CRED_NTLM_AUTH;
 267         }
 268         if (lpcfg_client_lanman_auth(gensec_security->settings->lp_ctx)) {
 269                 flags |= CLI_CRED_LANMAN_AUTH;
 270         }
 271
 272         nt_status = cli_credentials_get_ntlm_response(gensec_security->credentials, mem_ctx,
 273                                                       &flags, challenge_blob, target_info,
 274                                                       &lm_response, &nt_response,
 275                                                       &lm_session_key, &session_key);
 276
 277         if (!NT_STATUS_IS_OK(nt_status)) {
 278                 return nt_status;
 279         }
 280
 281         if (!(flags & CLI_CRED_LANMAN_AUTH)) {
 282                 /* LM Key is still possible, just silly, so we do not
 283                  * allow it. Fortunetly all LM crypto is off by
 284                  * default and we require command line options to end
 285                  * up here */
 286                 ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
 287         }
 288
 289         if (!(flags & CLI_CRED_NTLM2)) {
 290                 /* NTLM2 is incompatible... */
 291                 ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
 292         }
 293
 294         if ((ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY)
 295             && lpcfg_client_lanman_auth(gensec_security->settings->lp_ctx) && lm_session_key.length == 16) {
 296                 DATA_BLOB new_session_key = data_blob_talloc(mem_ctx, 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                 session_key = new_session_key;
 306                 dump_data_pw("LM session key\n", session_key.data, session_key.length);
 307         }
 308
 309
 310         /* Key exchange encryptes a new client-generated session key with
 311            the password-derived key */
 312         if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
 313                 /* Make up a new session key */
 314                 uint8_t client_session_key[16];
 315                 generate_secret_buffer(client_session_key, sizeof(client_session_key));
 316
 317                 /* Encrypt the new session key with the old one */
 318                 encrypted_session_key = data_blob_talloc(ntlmssp_state,
 319                                                          client_session_key, sizeof(client_session_key));
 320                 dump_data_pw("KEY_EXCH session key:\n", encrypted_session_key.data, encrypted_session_key.length);
 321                 arcfour_crypt(encrypted_session_key.data, session_key.data, encrypted_session_key.length);
 322                 dump_data_pw("KEY_EXCH session key (enc):\n", encrypted_session_key.data, encrypted_session_key.length);
 323
 324                 /* Mark the new session key as the 'real' session key */
 325                 session_key = data_blob_talloc(mem_ctx, client_session_key, sizeof(client_session_key));
 326         }
 327
 328         DEBUG(3, ("NTLMSSP: Set final flags:\n"));
 329         debug_ntlmssp_flags(ntlmssp_state->neg_flags);
 330
 331         /* this generates the actual auth packet */
 332         nt_status = msrpc_gen(mem_ctx,
 333                        out, auth_gen_string,
 334                        "NTLMSSP",
 335                        NTLMSSP_AUTH,
 336                        lm_response.data, lm_response.length,
 337                        nt_response.data, nt_response.length,
 338                        domain,
 339                        user,
 340                        cli_credentials_get_workstation(gensec_security->credentials),
 341                        encrypted_session_key.data, encrypted_session_key.length,
 342                        ntlmssp_state->neg_flags);
 343         if (!NT_STATUS_IS_OK(nt_status)) {
 344                 talloc_free(mem_ctx);
 345                 return nt_status;
 346         }
 347
 348         ntlmssp_state->session_key = session_key;
 349         talloc_steal(ntlmssp_state, session_key.data);
 350
 351         talloc_steal(out_mem_ctx, out->data);
 352
 353         ntlmssp_state->expected_state = NTLMSSP_DONE;
 354
 355         if (gensec_security->want_features & (GENSEC_FEATURE_SIGN|GENSEC_FEATURE_SEAL)) {
 356                 nt_status = ntlmssp_sign_init(ntlmssp_state);
 357                 if (!NT_STATUS_IS_OK(nt_status)) {
 358                         DEBUG(1, ("Could not setup NTLMSSP signing/sealing system (error was: %s)\n",
 359                                   nt_errstr(nt_status)));
 360                         talloc_free(mem_ctx);
 361                         return nt_status;
 362                 }
 363         }
 364
 365         talloc_free(mem_ctx);
 366         return NT_STATUS_OK;
 367 }
 368
 369 NTSTATUS gensec_ntlmssp_client_start(struct gensec_security *gensec_security)
 370 {
 371         struct gensec_ntlmssp_context *gensec_ntlmssp;
 372         struct ntlmssp_state *ntlmssp_state;
 373         NTSTATUS nt_status;
 374
 375         nt_status = gensec_ntlmssp_start(gensec_security);
 376         NT_STATUS_NOT_OK_RETURN(nt_status);
 377
 378         gensec_ntlmssp =
 379                 talloc_get_type_abort(gensec_security->private_data,
 380                                       struct gensec_ntlmssp_context);
 381
 382         ntlmssp_state = talloc_zero(gensec_ntlmssp,
 383                                     struct ntlmssp_state);
 384         if (!ntlmssp_state) {
 385                 return NT_STATUS_NO_MEMORY;
 386         }
 387
 388         gensec_ntlmssp->ntlmssp_state = ntlmssp_state;
 389
 390         ntlmssp_state = gensec_ntlmssp->ntlmssp_state;
 391
 392         ntlmssp_state->role = NTLMSSP_CLIENT;
 393
 394         ntlmssp_state->client.netbios_domain = lpcfg_workgroup(gensec_security->settings->lp_ctx);
 395         ntlmssp_state->client.netbios_name = cli_credentials_get_workstation(gensec_security->credentials);
 396
 397         ntlmssp_state->unicode = gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "unicode", true);
 398
 399         ntlmssp_state->use_nt_response = gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "send_nt_reponse", true);
 400
 401         ntlmssp_state->allow_lm_key = (lpcfg_client_lanman_auth(gensec_security->settings->lp_ctx)
 402                                               && (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "allow_lm_key", false)
 403                                                   || gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "lm_key", false)));
 404
 405         ntlmssp_state->use_ntlmv2 = lpcfg_client_ntlmv2_auth(gensec_security->settings->lp_ctx);
 406
 407         ntlmssp_state->expected_state = NTLMSSP_INITIAL;
 408
 409         ntlmssp_state->neg_flags =
 410                 NTLMSSP_NEGOTIATE_NTLM |
 411                 NTLMSSP_REQUEST_TARGET;
 412
 413         if (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "128bit", true)) {
 414                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_128;
 415         }
 416
 417         if (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "56bit", false)) {
 418                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_56;
 419         }
 420
 421         if (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "lm_key", false)) {
 422                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_LM_KEY;
 423         }
 424
 425         if (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "keyexchange", true)) {
 426                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_KEY_EXCH;
 427         }
 428
 429         if (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "alwayssign", true)) {
 430                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_ALWAYS_SIGN;
 431         }
 432
 433         if (gensec_setting_bool(gensec_security->settings, "ntlmssp_client", "ntlm2", true)) {
 434                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
 435         } else {
 436                 /* apparently we can't do ntlmv2 if we don't do ntlm2 */
 437                 ntlmssp_state->use_ntlmv2 = false;
 438         }
 439
 440         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 441                 /*
 442                  * We need to set this to allow a later SetPassword
 443                  * via the SAMR pipe to succeed. Strange.... We could
 444                  * also add  NTLMSSP_NEGOTIATE_SEAL here. JRA.
 445                  *
 446                  * Without this, Windows will not create the master key
 447                  * that it thinks is only used for NTLMSSP signing and
 448                  * sealing.  (It is actually pulled out and used directly)
 449                  */
 450                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 451         }
 452         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 453                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 454         }
 455         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 456                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SIGN;
 457                 ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_SEAL;
 458         }
 459
 460         return NT_STATUS_OK;
 461 }