source4/rpc_server/dcesrv_auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    server side dcerpc authentication code
   5
   6    Copyright (C) Andrew Tridgell 2003
   7    Copyright (C) Stefan (metze) Metzmacher 2004
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "rpc_server/dcerpc_server.h"
  25 #include "rpc_server/dcerpc_server_proto.h"
  26 #include "rpc_server/common/proto.h"
  27 #include "librpc/rpc/dcerpc_proto.h"
  28 #include "librpc/gen_ndr/ndr_dcerpc.h"
  29 #include "auth/credentials/credentials.h"
  30 #include "auth/gensec/gensec.h"
  31 #include "auth/auth.h"
  32 #include "param/param.h"
  33 #include "librpc/rpc/rpc_common.h"
  34
  35 /*
  36   parse any auth information from a dcerpc bind request
  37   return false if we can't handle the auth request for some
  38   reason (in which case we send a bind_nak)
  39 */
  40 bool dcesrv_auth_bind(struct dcesrv_call_state *call)
  41 {
  42         struct cli_credentials *server_credentials = NULL;
  43         struct ncacn_packet *pkt = &call->pkt;
  44         struct dcesrv_connection *dce_conn = call->conn;
  45         struct dcesrv_auth *auth = &dce_conn->auth_state;
  46         NTSTATUS status;
  47
  48         if (pkt->auth_length == 0) {
  49                 enum dcerpc_transport_t transport =
  50                         dcerpc_binding_get_transport(call->conn->endpoint->ep_description);
  51                 const char *auth_type = derpc_transport_string_by_transport(transport);
  52                 const char *transport_protection = AUTHZ_TRANSPORT_PROTECTION_NONE;
  53                 if (transport == NCACN_NP) {
  54                         transport_protection = AUTHZ_TRANSPORT_PROTECTION_SMB;
  55                 }
  56                 auth->auth_type = DCERPC_AUTH_TYPE_NONE;
  57                 auth->auth_level = DCERPC_AUTH_LEVEL_NONE;
  58                 auth->auth_context_id = 0;
  59
  60                 /*
  61                  * Log the authorization to this RPC interface.  This
  62                  * covered ncacn_np pass-through auth, and anonymous
  63                  * DCE/RPC (eg epmapper, netlogon etc)
  64                  */
  65                 log_successful_authz_event(call->conn->remote_address,
  66                                            call->conn->local_address,
  67                                            "DCE/RPC",
  68                                            auth_type,
  69                                            transport_protection,
  70                                            call->conn->auth_state.session_info);
  71
  72                 return true;
  73         }
  74
  75         status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.bind.auth_info,
  76                                           &call->in_auth_info,
  77                                           NULL, true);
  78         if (!NT_STATUS_IS_OK(status)) {
  79                 /*
  80                  * Setting DCERPC_AUTH_LEVEL_NONE,
  81                  * gives the caller the reject_reason
  82                  * as auth_context_id.
  83                  *
  84                  * Note: DCERPC_AUTH_LEVEL_NONE == 1
  85                  */
  86                 auth->auth_type = DCERPC_AUTH_TYPE_NONE;
  87                 auth->auth_level = DCERPC_AUTH_LEVEL_NONE;
  88                 auth->auth_context_id =
  89                         DCERPC_BIND_NAK_REASON_PROTOCOL_VERSION_NOT_SUPPORTED;
  90                 return false;
  91         }
  92
  93         switch (call->in_auth_info.auth_level) {
  94         case DCERPC_AUTH_LEVEL_CONNECT:
  95         case DCERPC_AUTH_LEVEL_CALL:
  96         case DCERPC_AUTH_LEVEL_PACKET:
  97         case DCERPC_AUTH_LEVEL_INTEGRITY:
  98         case DCERPC_AUTH_LEVEL_PRIVACY:
  99                 /*
 100                  * We evaluate auth_type only if auth_level was valid
 101                  */
 102                 break;
 103         default:
 104                 /*
 105                  * Setting DCERPC_AUTH_LEVEL_NONE,
 106                  * gives the caller the reject_reason
 107                  * as auth_context_id.
 108                  *
 109                  * Note: DCERPC_AUTH_LEVEL_NONE == 1
 110                  */
 111                 auth->auth_type = DCERPC_AUTH_TYPE_NONE;
 112                 auth->auth_level = DCERPC_AUTH_LEVEL_NONE;
 113                 auth->auth_context_id = DCERPC_BIND_NAK_REASON_NOT_SPECIFIED;
 114                 return false;
 115         }
 116
 117         auth->auth_type = call->in_auth_info.auth_type;
 118         auth->auth_level = call->in_auth_info.auth_level;
 119         auth->auth_context_id = call->in_auth_info.auth_context_id;
 120
 121         server_credentials
 122                 = cli_credentials_init(call);
 123         if (!server_credentials) {
 124                 DEBUG(1, ("Failed to init server credentials\n"));
 125                 return false;
 126         }
 127
 128         cli_credentials_set_conf(server_credentials, call->conn->dce_ctx->lp_ctx);
 129         status = cli_credentials_set_machine_account(server_credentials, call->conn->dce_ctx->lp_ctx);
 130         if (!NT_STATUS_IS_OK(status)) {
 131                 DEBUG(1, ("Failed to obtain server credentials: %s\n",
 132                           nt_errstr(status)));
 133                 return false;
 134         }
 135
 136         status = samba_server_gensec_start(dce_conn, call->event_ctx,
 137                                            call->msg_ctx,
 138                                            call->conn->dce_ctx->lp_ctx,
 139                                            server_credentials,
 140                                            NULL,
 141                                            &auth->gensec_security);
 142         if (!NT_STATUS_IS_OK(status)) {
 143                 DEBUG(1, ("Failed to call samba_server_gensec_start %s\n",
 144                           nt_errstr(status)));
 145                 return false;
 146         }
 147
 148         /*
 149          * We have to call this because we set the target_service for
 150          * Kerberos to NULL above, and in any case we wish to log a
 151          * more specific service target.
 152          *
 153          */
 154         status = gensec_set_target_service_description(auth->gensec_security,
 155                                                        "DCE/RPC");
 156         if (!NT_STATUS_IS_OK(status)) {
 157                 DEBUG(1, ("Failed to call gensec_set_target_service_description %s\n",
 158                           nt_errstr(status)));
 159                 return false;
 160         }
 161
 162         if (call->conn->remote_address != NULL) {
 163                 status = gensec_set_remote_address(auth->gensec_security,
 164                                                 call->conn->remote_address);
 165                 if (!NT_STATUS_IS_OK(status)) {
 166                         DEBUG(1, ("Failed to call gensec_set_remote_address() %s\n",
 167                                   nt_errstr(status)));
 168                         return false;
 169                 }
 170         }
 171
 172         if (call->conn->local_address != NULL) {
 173                 status = gensec_set_local_address(auth->gensec_security,
 174                                                   call->conn->local_address);
 175                 if (!NT_STATUS_IS_OK(status)) {
 176                         DEBUG(1, ("Failed to call gensec_set_local_address() %s\n",
 177                                   nt_errstr(status)));
 178                         return false;
 179                 }
 180         }
 181
 182         status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_type,
 183                                                auth->auth_level);
 184         if (!NT_STATUS_IS_OK(status)) {
 185                 const char *backend_name =
 186                         gensec_get_name_by_authtype(auth->gensec_security,
 187                                                     auth->auth_type);
 188
 189                 DEBUG(3, ("Failed to start GENSEC mechanism for DCERPC server: "
 190                           "auth_type=%d (%s), auth_level=%d: %s\n",
 191                           (int)auth->auth_type, backend_name,
 192                           (int)auth->auth_level,
 193                           nt_errstr(status)));
 194
 195                 /*
 196                  * Setting DCERPC_AUTH_LEVEL_NONE,
 197                  * gives the caller the reject_reason
 198                  * as auth_context_id.
 199                  *
 200                  * Note: DCERPC_AUTH_LEVEL_NONE == 1
 201                  */
 202                 auth->auth_type = DCERPC_AUTH_TYPE_NONE;
 203                 auth->auth_level = DCERPC_AUTH_LEVEL_NONE;
 204                 if (backend_name != NULL) {
 205                         auth->auth_context_id =
 206                                 DCERPC_BIND_NAK_REASON_INVALID_CHECKSUM;
 207                 } else {
 208                         auth->auth_context_id =
 209                                 DCERPC_BIND_NAK_REASON_INVALID_AUTH_TYPE;
 210                 }
 211                 return false;
 212         }
 213
 214         return true;
 215 }
 216
 217 /*
 218   add any auth information needed in a bind ack, and process the authentication
 219   information found in the bind.
 220 */
 221 NTSTATUS dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
 222 {
 223         struct dcesrv_connection *dce_conn = call->conn;
 224         NTSTATUS status;
 225         bool want_header_signing = false;
 226
 227         dce_conn->allow_alter = true;
 228         dce_conn->allow_auth3 = true;
 229
 230         if (call->pkt.auth_length == 0) {
 231                 dce_conn->auth_state.auth_finished = true;
 232                 dce_conn->allow_request = true;
 233                 return NT_STATUS_OK;
 234         }
 235
 236         /* We can't work without an existing gensec state */
 237         if (!call->conn->auth_state.gensec_security) {
 238                 return NT_STATUS_INTERNAL_ERROR;
 239         }
 240
 241         if (call->pkt.pfc_flags & DCERPC_PFC_FLAG_SUPPORT_HEADER_SIGN) {
 242                 dce_conn->auth_state.client_hdr_signing = true;
 243                 want_header_signing = true;
 244         }
 245
 246         if (!lpcfg_parm_bool(call->conn->dce_ctx->lp_ctx, NULL, "dcesrv","header signing", true)) {
 247                 want_header_signing = false;
 248         }
 249
 250         call->_out_auth_info = (struct dcerpc_auth) {
 251                 .auth_type = dce_conn->auth_state.auth_type,
 252                 .auth_level = dce_conn->auth_state.auth_level,
 253                 .auth_context_id = dce_conn->auth_state.auth_context_id,
 254         };
 255         call->out_auth_info = &call->_out_auth_info;
 256
 257         status = gensec_update_ev(dce_conn->auth_state.gensec_security,
 258                                call, call->event_ctx,
 259                                call->in_auth_info.credentials,
 260                                &call->out_auth_info->credentials);
 261
 262         if (NT_STATUS_IS_OK(status)) {
 263                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
 264                                              dce_conn,
 265                                              &dce_conn->auth_state.session_info);
 266                 if (!NT_STATUS_IS_OK(status)) {
 267                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
 268                         return status;
 269                 }
 270                 dce_conn->auth_state.auth_finished = true;
 271                 dce_conn->allow_request = true;
 272
 273                 if (!gensec_have_feature(dce_conn->auth_state.gensec_security,
 274                                          GENSEC_FEATURE_SIGN_PKT_HEADER))
 275                 {
 276                         want_header_signing = false;
 277                 }
 278
 279                 if (want_header_signing) {
 280                         gensec_want_feature(dce_conn->auth_state.gensec_security,
 281                                             GENSEC_FEATURE_SIGN_PKT_HEADER);
 282                         dce_conn->auth_state.hdr_signing = true;
 283                         pkt->pfc_flags |= DCERPC_PFC_FLAG_SUPPORT_HEADER_SIGN;
 284                 }
 285
 286                 /* Now that we are authenticated, go back to the generic session key... */
 287                 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
 288                 return NT_STATUS_OK;
 289         } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 290                 if (!gensec_have_feature(dce_conn->auth_state.gensec_security,
 291                                          GENSEC_FEATURE_SIGN_PKT_HEADER))
 292                 {
 293                         want_header_signing = false;
 294                 }
 295
 296                 if (want_header_signing) {
 297                         gensec_want_feature(dce_conn->auth_state.gensec_security,
 298                                             GENSEC_FEATURE_SIGN_PKT_HEADER);
 299                         dce_conn->auth_state.hdr_signing = true;
 300                         pkt->pfc_flags |= DCERPC_PFC_FLAG_SUPPORT_HEADER_SIGN;
 301                 }
 302
 303                 return NT_STATUS_OK;
 304         } else {
 305                 DEBUG(4, ("GENSEC mech rejected the incoming authentication at bind_ack: %s\n",
 306                           nt_errstr(status)));
 307                 return status;
 308         }
 309 }
 310
 311
 312 /*
 313   process the final stage of a auth request
 314 */
 315 bool dcesrv_auth_auth3(struct dcesrv_call_state *call)
 316 {
 317         struct ncacn_packet *pkt = &call->pkt;
 318         struct dcesrv_connection *dce_conn = call->conn;
 319         NTSTATUS status;
 320
 321         if (pkt->auth_length == 0) {
 322                 return false;
 323         }
 324
 325         if (dce_conn->auth_state.auth_finished) {
 326                 return false;
 327         }
 328
 329         /* We can't work without an existing gensec state */
 330         if (!dce_conn->auth_state.gensec_security) {
 331                 return false;
 332         }
 333
 334         status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.auth3.auth_info,
 335                                           &call->in_auth_info, NULL, true);
 336         if (!NT_STATUS_IS_OK(status)) {
 337                 /*
 338                  * Windows returns DCERPC_NCA_S_FAULT_REMOTE_NO_MEMORY
 339                  * instead of DCERPC_NCA_S_PROTO_ERROR.
 340                  */
 341                 call->fault_code = DCERPC_NCA_S_FAULT_REMOTE_NO_MEMORY;
 342                 return false;
 343         }
 344
 345         if (call->in_auth_info.auth_type != dce_conn->auth_state.auth_type) {
 346                 return false;
 347         }
 348
 349         if (call->in_auth_info.auth_level != dce_conn->auth_state.auth_level) {
 350                 return false;
 351         }
 352
 353         if (call->in_auth_info.auth_context_id != dce_conn->auth_state.auth_context_id) {
 354                 return false;
 355         }
 356
 357         call->_out_auth_info = (struct dcerpc_auth) {
 358                 .auth_type = dce_conn->auth_state.auth_type,
 359                 .auth_level = dce_conn->auth_state.auth_level,
 360                 .auth_context_id = dce_conn->auth_state.auth_context_id,
 361         };
 362         call->out_auth_info = &call->_out_auth_info;
 363
 364         /* Pass the extra data we got from the client down to gensec for processing */
 365         status = gensec_update_ev(dce_conn->auth_state.gensec_security,
 366                                call, call->event_ctx,
 367                                call->in_auth_info.credentials,
 368                                &call->out_auth_info->credentials);
 369         if (NT_STATUS_IS_OK(status)) {
 370                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
 371                                              dce_conn,
 372                                              &dce_conn->auth_state.session_info);
 373                 if (!NT_STATUS_IS_OK(status)) {
 374                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
 375                         return false;
 376                 }
 377                 dce_conn->auth_state.auth_finished = true;
 378                 dce_conn->allow_request = true;
 379
 380                 /* Now that we are authenticated, go back to the generic session key... */
 381                 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
 382
 383                 if (call->out_auth_info->credentials.length != 0) {
 384
 385                         DEBUG(4, ("GENSEC produced output token (len=%u) at bind_auth3\n",
 386                                   (unsigned)call->out_auth_info->credentials.length));
 387                         return false;
 388                 }
 389                 return true;
 390         } else {
 391                 DEBUG(4, ("GENSEC mech rejected the incoming authentication at bind_auth3: %s\n",
 392                           nt_errstr(status)));
 393                 return false;
 394         }
 395 }
 396
 397 /*
 398   parse any auth information from a dcerpc alter request
 399   return false if we can't handle the auth request for some
 400   reason (in which case we send a bind_nak (is this true for here?))
 401 */
 402 bool dcesrv_auth_alter(struct dcesrv_call_state *call)
 403 {
 404         struct ncacn_packet *pkt = &call->pkt;
 405         struct dcesrv_connection *dce_conn = call->conn;
 406         NTSTATUS status;
 407
 408         /* on a pure interface change there is no auth blob */
 409         if (pkt->auth_length == 0) {
 410                 if (!dce_conn->auth_state.auth_finished) {
 411                         return false;
 412                 }
 413                 return true;
 414         }
 415
 416         if (dce_conn->auth_state.auth_finished) {
 417                 call->fault_code = DCERPC_FAULT_ACCESS_DENIED;
 418                 return false;
 419         }
 420
 421         /* We can't work without an existing gensec state */
 422         if (!dce_conn->auth_state.gensec_security) {
 423                 return false;
 424         }
 425
 426         status = dcerpc_pull_auth_trailer(pkt, call, &pkt->u.alter.auth_info,
 427                                           &call->in_auth_info, NULL, true);
 428         if (!NT_STATUS_IS_OK(status)) {
 429                 call->fault_code = DCERPC_NCA_S_PROTO_ERROR;
 430                 return false;
 431         }
 432
 433         if (call->in_auth_info.auth_type == DCERPC_AUTH_TYPE_NONE) {
 434                 call->fault_code = DCERPC_FAULT_ACCESS_DENIED;
 435                 return false;
 436         }
 437
 438         if (call->in_auth_info.auth_type != dce_conn->auth_state.auth_type) {
 439                 return false;
 440         }
 441
 442         if (call->in_auth_info.auth_level != dce_conn->auth_state.auth_level) {
 443                 return false;
 444         }
 445
 446         if (call->in_auth_info.auth_context_id != dce_conn->auth_state.auth_context_id) {
 447                 return false;
 448         }
 449
 450         return true;
 451 }
 452
 453 /*
 454   add any auth information needed in a alter ack, and process the authentication
 455   information found in the alter.
 456 */
 457 NTSTATUS dcesrv_auth_alter_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
 458 {
 459         struct dcesrv_connection *dce_conn = call->conn;
 460         NTSTATUS status;
 461
 462         /* on a pure interface change there is no auth_info structure
 463            setup */
 464         if (call->pkt.auth_length == 0) {
 465                 return NT_STATUS_OK;
 466         }
 467
 468         if (!call->conn->auth_state.gensec_security) {
 469                 return NT_STATUS_INTERNAL_ERROR;
 470         }
 471
 472         call->_out_auth_info = (struct dcerpc_auth) {
 473                 .auth_type = dce_conn->auth_state.auth_type,
 474                 .auth_level = dce_conn->auth_state.auth_level,
 475                 .auth_context_id = dce_conn->auth_state.auth_context_id,
 476         };
 477         call->out_auth_info = &call->_out_auth_info;
 478
 479         status = gensec_update_ev(dce_conn->auth_state.gensec_security,
 480                                call, call->event_ctx,
 481                                call->in_auth_info.credentials,
 482                                &call->out_auth_info->credentials);
 483
 484         if (NT_STATUS_IS_OK(status)) {
 485                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
 486                                              dce_conn,
 487                                              &dce_conn->auth_state.session_info);
 488                 if (!NT_STATUS_IS_OK(status)) {
 489                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
 490                         return status;
 491                 }
 492                 dce_conn->auth_state.auth_finished = true;
 493                 dce_conn->allow_request = true;
 494
 495                 /* Now that we are authenticated, got back to the generic session key... */
 496                 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
 497                 return NT_STATUS_OK;
 498         } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 499                 return NT_STATUS_OK;
 500         }
 501
 502         DEBUG(4, ("GENSEC mech rejected the incoming authentication at auth alter_ack: %s\n",
 503                   nt_errstr(status)));
 504         return status;
 505 }
 506
 507 /*
 508   check credentials on a packet
 509 */
 510 bool dcesrv_auth_pkt_pull(struct dcesrv_call_state *call,
 511                           DATA_BLOB *full_packet,
 512                           uint8_t required_flags,
 513                           uint8_t optional_flags,
 514                           uint8_t payload_offset,
 515                           DATA_BLOB *payload_and_verifier)
 516 {
 517         struct ncacn_packet *pkt = &call->pkt;
 518         struct dcesrv_connection *dce_conn = call->conn;
 519         const struct dcerpc_auth tmp_auth = {
 520                 .auth_type = dce_conn->auth_state.auth_type,
 521                 .auth_level = dce_conn->auth_state.auth_level,
 522                 .auth_context_id = dce_conn->auth_state.auth_context_id,
 523         };
 524         NTSTATUS status;
 525
 526         if (!dce_conn->allow_request) {
 527                 call->fault_code = DCERPC_NCA_S_PROTO_ERROR;
 528                 return false;
 529         }
 530
 531         if (dce_conn->auth_state.auth_invalid) {
 532                 return false;
 533         }
 534
 535         status = dcerpc_ncacn_pull_pkt_auth(&tmp_auth,
 536                                             dce_conn->auth_state.gensec_security,
 537                                             call,
 538                                             pkt->ptype,
 539                                             required_flags,
 540                                             optional_flags,
 541                                             payload_offset,
 542                                             payload_and_verifier,
 543                                             full_packet,
 544                                             pkt);
 545         if (NT_STATUS_EQUAL(status, NT_STATUS_RPC_PROTOCOL_ERROR)) {
 546                 call->fault_code = DCERPC_NCA_S_PROTO_ERROR;
 547                 return false;
 548         }
 549         if (NT_STATUS_EQUAL(status, NT_STATUS_RPC_UNSUPPORTED_AUTHN_LEVEL)) {
 550                 call->fault_code = DCERPC_NCA_S_UNSUPPORTED_AUTHN_LEVEL;
 551                 return false;
 552         }
 553         if (NT_STATUS_EQUAL(status, NT_STATUS_RPC_SEC_PKG_ERROR)) {
 554                 call->fault_code = DCERPC_FAULT_SEC_PKG_ERROR;
 555                 return false;
 556         }
 557         if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 558                 call->fault_code = DCERPC_FAULT_ACCESS_DENIED;
 559                 return false;
 560         }
 561         if (!NT_STATUS_IS_OK(status)) {
 562                 return false;
 563         }
 564
 565         return true;
 566 }
 567
 568 /*
 569    push a signed or sealed dcerpc request packet into a blob
 570 */
 571 bool dcesrv_auth_pkt_push(struct dcesrv_call_state *call,
 572                           DATA_BLOB *blob, size_t sig_size,
 573                           uint8_t payload_offset,
 574                           const DATA_BLOB *payload,
 575                           const struct ncacn_packet *pkt)
 576 {
 577         struct dcesrv_connection *dce_conn = call->conn;
 578         const struct dcerpc_auth tmp_auth = {
 579                 .auth_type = dce_conn->auth_state.auth_type,
 580                 .auth_level = dce_conn->auth_state.auth_level,
 581                 .auth_context_id = dce_conn->auth_state.auth_context_id,
 582         };
 583         NTSTATUS status;
 584
 585         status = dcerpc_ncacn_push_pkt_auth(&tmp_auth,
 586                                             dce_conn->auth_state.gensec_security,
 587                                             call, blob, sig_size,
 588                                             payload_offset,
 589                                             payload,
 590                                             pkt);
 591         return NT_STATUS_IS_OK(status);
 592 }