source3/smbd/smb2_sesssetup.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Core SMB2 server
   4
   5    Copyright (C) Stefan Metzmacher 2009
   6    Copyright (C) Jeremy Allison 2010
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "../libcli/smb/smb_common.h"
  26 #include "../auth/gensec/gensec.h"
  27 #include "auth.h"
  28 #include "../lib/tsocket/tsocket.h"
  29 #include "../libcli/security/security.h"
  30 #include "../lib/util/tevent_ntstatus.h"
  31
  32 static struct tevent_req *smbd_smb2_session_setup_send(TALLOC_CTX *mem_ctx,
  33                                         struct tevent_context *ev,
  34                                         struct smbd_smb2_request *smb2req,
  35                                         uint64_t in_session_id,
  36                                         uint8_t in_flags,
  37                                         uint8_t in_security_mode,
  38                                         uint64_t in_previous_session_id,
  39                                         DATA_BLOB in_security_buffer);
  40 static NTSTATUS smbd_smb2_session_setup_recv(struct tevent_req *req,
  41                                         uint16_t *out_session_flags,
  42                                         TALLOC_CTX *mem_ctx,
  43                                         DATA_BLOB *out_security_buffer,
  44                                         uint64_t *out_session_id);
  45
  46 static void smbd_smb2_request_sesssetup_done(struct tevent_req *subreq);
  47
  48 NTSTATUS smbd_smb2_request_process_sesssetup(struct smbd_smb2_request *smb2req)
  49 {
  50         const uint8_t *inhdr;
  51         const uint8_t *inbody;
  52         int i = smb2req->current_idx;
  53         uint64_t in_session_id;
  54         uint8_t in_flags;
  55         uint8_t in_security_mode;
  56         uint64_t in_previous_session_id;
  57         uint16_t in_security_offset;
  58         uint16_t in_security_length;
  59         DATA_BLOB in_security_buffer;
  60         NTSTATUS status;
  61         struct tevent_req *subreq;
  62
  63         status = smbd_smb2_request_verify_sizes(smb2req, 0x19);
  64         if (!NT_STATUS_IS_OK(status)) {
  65                 return smbd_smb2_request_error(smb2req, status);
  66         }
  67         inhdr = (const uint8_t *)smb2req->in.vector[i+0].iov_base;
  68         inbody = (const uint8_t *)smb2req->in.vector[i+1].iov_base;
  69
  70         in_session_id = BVAL(inhdr, SMB2_HDR_SESSION_ID);
  71
  72         in_flags = CVAL(inbody, 0x02);
  73         in_security_mode = CVAL(inbody, 0x03);
  74         /* Capabilities = IVAL(inbody, 0x04) */
  75         /* Channel = IVAL(inbody, 0x08) */
  76         in_security_offset = SVAL(inbody, 0x0C);
  77         in_security_length = SVAL(inbody, 0x0E);
  78         in_previous_session_id = BVAL(inbody, 0x10);
  79
  80         if (in_security_offset != (SMB2_HDR_BODY + smb2req->in.vector[i+1].iov_len)) {
  81                 return smbd_smb2_request_error(smb2req, NT_STATUS_INVALID_PARAMETER);
  82         }
  83
  84         if (in_security_length > smb2req->in.vector[i+2].iov_len) {
  85                 return smbd_smb2_request_error(smb2req, NT_STATUS_INVALID_PARAMETER);
  86         }
  87
  88         in_security_buffer.data = (uint8_t *)smb2req->in.vector[i+2].iov_base;
  89         in_security_buffer.length = in_security_length;
  90
  91         subreq = smbd_smb2_session_setup_send(smb2req,
  92                                               smb2req->sconn->ev_ctx,
  93                                               smb2req,
  94                                               in_session_id,
  95                                               in_flags,
  96                                               in_security_mode,
  97                                               in_previous_session_id,
  98                                               in_security_buffer);
  99         if (subreq == NULL) {
 100                 return smbd_smb2_request_error(smb2req, NT_STATUS_NO_MEMORY);
 101         }
 102         tevent_req_set_callback(subreq, smbd_smb2_request_sesssetup_done, smb2req);
 103
 104         return smbd_smb2_request_pending_queue(smb2req, subreq, 500);
 105 }
 106
 107 static void smbd_smb2_request_sesssetup_done(struct tevent_req *subreq)
 108 {
 109         struct smbd_smb2_request *smb2req =
 110                 tevent_req_callback_data(subreq,
 111                 struct smbd_smb2_request);
 112         int i = smb2req->current_idx;
 113         uint8_t *outhdr;
 114         DATA_BLOB outbody;
 115         DATA_BLOB outdyn;
 116         uint16_t out_session_flags;
 117         uint64_t out_session_id;
 118         uint16_t out_security_offset;
 119         DATA_BLOB out_security_buffer = data_blob_null;
 120         NTSTATUS status;
 121         NTSTATUS error; /* transport error */
 122
 123         status = smbd_smb2_session_setup_recv(subreq,
 124                                               &out_session_flags,
 125                                               smb2req,
 126                                               &out_security_buffer,
 127                                               &out_session_id);
 128         TALLOC_FREE(subreq);
 129         if (!NT_STATUS_IS_OK(status) &&
 130             !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 131                 status = nt_status_squash(status);
 132                 error = smbd_smb2_request_error(smb2req, status);
 133                 if (!NT_STATUS_IS_OK(error)) {
 134                         smbd_server_connection_terminate(smb2req->sconn,
 135                                                          nt_errstr(error));
 136                         return;
 137                 }
 138                 return;
 139         }
 140
 141         out_security_offset = SMB2_HDR_BODY + 0x08;
 142
 143         outhdr = (uint8_t *)smb2req->out.vector[i].iov_base;
 144
 145         outbody = data_blob_talloc(smb2req->out.vector, NULL, 0x08);
 146         if (outbody.data == NULL) {
 147                 error = smbd_smb2_request_error(smb2req, NT_STATUS_NO_MEMORY);
 148                 if (!NT_STATUS_IS_OK(error)) {
 149                         smbd_server_connection_terminate(smb2req->sconn,
 150                                                          nt_errstr(error));
 151                         return;
 152                 }
 153                 return;
 154         }
 155
 156         SBVAL(outhdr, SMB2_HDR_SESSION_ID, out_session_id);
 157
 158         SSVAL(outbody.data, 0x00, 0x08 + 1);    /* struct size */
 159         SSVAL(outbody.data, 0x02,
 160               out_session_flags);               /* session flags */
 161         SSVAL(outbody.data, 0x04,
 162               out_security_offset);             /* security buffer offset */
 163         SSVAL(outbody.data, 0x06,
 164               out_security_buffer.length);      /* security buffer length */
 165
 166         outdyn = out_security_buffer;
 167
 168         error = smbd_smb2_request_done_ex(smb2req, status, outbody, &outdyn,
 169                                            __location__);
 170         if (!NT_STATUS_IS_OK(error)) {
 171                 smbd_server_connection_terminate(smb2req->sconn,
 172                                                  nt_errstr(error));
 173                 return;
 174         }
 175 }
 176
 177 static NTSTATUS smbd_smb2_auth_generic_return(struct smbXsrv_session *session,
 178                                         struct smbd_smb2_request *smb2req,
 179                                         uint8_t in_security_mode,
 180                                         uint64_t in_previous_session_id,
 181                                         DATA_BLOB in_security_buffer,
 182                                         uint16_t *out_session_flags,
 183                                         uint64_t *out_session_id)
 184 {
 185         NTSTATUS status;
 186         bool guest = false;
 187         uint8_t session_key[16];
 188         struct smbXsrv_session *x = session;
 189         struct auth_session_info *session_info;
 190         struct smbXsrv_connection *conn = session->connection;
 191
 192         if ((in_security_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) ||
 193             lp_server_signing() == SMB_SIGNING_REQUIRED) {
 194                 x->global->signing_required = true;
 195         }
 196
 197         status = gensec_session_info(session->gensec,
 198                                      session->global,
 199                                      &session_info);
 200         if (!NT_STATUS_IS_OK(status)) {
 201                 TALLOC_FREE(session);
 202                 return status;
 203         }
 204
 205         if (security_session_user_level(session_info, NULL) < SECURITY_USER) {
 206                 /* we map anonymous to guest internally */
 207                 *out_session_flags |= SMB2_SESSION_FLAG_IS_GUEST;
 208                 *out_session_flags |= SMB2_SESSION_FLAG_IS_NULL;
 209                 /* force no signing */
 210                 x->global->signing_required = false;
 211                 guest = true;
 212         }
 213
 214         ZERO_STRUCT(session_key);
 215         memcpy(session_key, session_info->session_key.data,
 216                MIN(session_info->session_key.length, sizeof(session_key)));
 217
 218         x->global->signing_key = data_blob_talloc(x->global,
 219                                                   session_key,
 220                                                   sizeof(session_key));
 221         if (x->global->signing_key.data == NULL) {
 222                 ZERO_STRUCT(session_key);
 223                 TALLOC_FREE(session);
 224                 return NT_STATUS_NO_MEMORY;
 225         }
 226
 227         if (conn->protocol >= PROTOCOL_SMB2_24) {
 228                 const DATA_BLOB label = data_blob_string_const_null("SMB2AESCMAC");
 229                 const DATA_BLOB context = data_blob_string_const_null("SmbSign");
 230
 231                 smb2_key_derivation(session_key, sizeof(session_key),
 232                                     label.data, label.length,
 233                                     context.data, context.length,
 234                                     x->global->signing_key.data);
 235         }
 236
 237         x->global->application_key = data_blob_dup_talloc(x->global,
 238                                                 x->global->signing_key);
 239         if (x->global->application_key.data == NULL) {
 240                 ZERO_STRUCT(session_key);
 241                 TALLOC_FREE(session);
 242                 return NT_STATUS_NO_MEMORY;
 243         }
 244
 245         if (conn->protocol >= PROTOCOL_SMB2_24) {
 246                 const DATA_BLOB label = data_blob_string_const_null("SMB2APP");
 247                 const DATA_BLOB context = data_blob_string_const_null("SmbRpc");
 248
 249                 smb2_key_derivation(session_key, sizeof(session_key),
 250                                     label.data, label.length,
 251                                     context.data, context.length,
 252                                     x->global->application_key.data);
 253         }
 254         ZERO_STRUCT(session_key);
 255
 256         x->global->channels[0].signing_key = data_blob_dup_talloc(x->global->channels,
 257                                                 x->global->signing_key);
 258         if (x->global->channels[0].signing_key.data == NULL) {
 259                 TALLOC_FREE(session);
 260                 return NT_STATUS_NO_MEMORY;
 261         }
 262
 263         data_blob_clear_free(&session_info->session_key);
 264         session_info->session_key = data_blob_dup_talloc(session_info,
 265                                                 x->global->application_key);
 266         if (session_info->session_key.data == NULL) {
 267                 TALLOC_FREE(session);
 268                 return NT_STATUS_NO_MEMORY;
 269         }
 270
 271         session->compat = talloc_zero(session, struct user_struct);
 272         if (session->compat == NULL) {
 273                 TALLOC_FREE(session);
 274                 return NT_STATUS_NO_MEMORY;
 275         }
 276         session->compat->session = session;
 277         session->compat->homes_snum = -1;
 278         session->compat->session_info = session_info;
 279         session->compat->session_keystr = NULL;
 280         session->compat->vuid = session->global->session_wire_id;
 281         DLIST_ADD(smb2req->sconn->users, session->compat);
 282         smb2req->sconn->num_users++;
 283
 284         if (security_session_user_level(session_info, NULL) >= SECURITY_USER) {
 285                 session->compat->homes_snum =
 286                         register_homes_share(session_info->unix_info->unix_name);
 287         }
 288
 289         if (!session_claim(smb2req->sconn, session->compat)) {
 290                 DEBUG(1, ("smb2: Failed to claim session "
 291                         "for vuid=%llu\n",
 292                         (unsigned long long)session->compat->vuid));
 293                 TALLOC_FREE(session);
 294                 return NT_STATUS_LOGON_FAILURE;
 295         }
 296
 297         set_current_user_info(session_info->unix_info->sanitized_username,
 298                               session_info->unix_info->unix_name,
 299                               session_info->info->domain_name);
 300
 301         reload_services(smb2req->sconn, conn_snum_used, true);
 302
 303         session->status = NT_STATUS_OK;
 304         session->global->auth_session_info = session_info;
 305         session->global->auth_session_info_seqnum += 1;
 306         session->global->channels[0].auth_session_info_seqnum =
 307                 session->global->auth_session_info_seqnum;
 308
 309         status = smbXsrv_session_update(session);
 310         if (!NT_STATUS_IS_OK(status)) {
 311                 DEBUG(0, ("smb2: Failed to update session for vuid=%llu - %s\n",
 312                           (unsigned long long)session->compat->vuid,
 313                           nt_errstr(status)));
 314                 TALLOC_FREE(session);
 315                 return NT_STATUS_LOGON_FAILURE;
 316         }
 317
 318         /*
 319          * we attach the session to the request
 320          * so that the response can be signed
 321          */
 322         smb2req->session = session;
 323         if (!guest) {
 324                 smb2req->do_signing = true;
 325         }
 326
 327         global_client_caps |= (CAP_LEVEL_II_OPLOCKS|CAP_STATUS32);
 328
 329         *out_session_id = session->global->session_wire_id;
 330
 331         return NT_STATUS_OK;
 332 }
 333
 334 static NTSTATUS smbd_smb2_auth_generic(struct smbXsrv_session *session,
 335                                        struct smbd_smb2_request *smb2req,
 336                                        uint8_t in_security_mode,
 337                                        uint64_t in_previous_session_id,
 338                                        DATA_BLOB in_security_buffer,
 339                                        uint16_t *out_session_flags,
 340                                        DATA_BLOB *out_security_buffer,
 341                                        uint64_t *out_session_id)
 342 {
 343         NTSTATUS status;
 344
 345         *out_security_buffer = data_blob_null;
 346
 347         if (session->gensec == NULL) {
 348                 status = auth_generic_prepare(session,
 349                                               session->connection->remote_address,
 350                                               &session->gensec);
 351                 if (!NT_STATUS_IS_OK(status)) {
 352                         TALLOC_FREE(session);
 353                         return status;
 354                 }
 355
 356                 gensec_want_feature(session->gensec, GENSEC_FEATURE_SESSION_KEY);
 357                 gensec_want_feature(session->gensec, GENSEC_FEATURE_UNIX_TOKEN);
 358
 359                 status = gensec_start_mech_by_oid(session->gensec,
 360                                                   GENSEC_OID_SPNEGO);
 361                 if (!NT_STATUS_IS_OK(status)) {
 362                         TALLOC_FREE(session);
 363                         return status;
 364                 }
 365         }
 366
 367         become_root();
 368         status = gensec_update(session->gensec,
 369                                smb2req, NULL,
 370                                in_security_buffer,
 371                                out_security_buffer);
 372         unbecome_root();
 373         if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 374             !NT_STATUS_IS_OK(status)) {
 375                 TALLOC_FREE(session);
 376                 return nt_status_squash(status);
 377         }
 378
 379         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 380                 *out_session_id = session->global->session_wire_id;
 381                 return status;
 382         }
 383
 384         return smbd_smb2_auth_generic_return(session,
 385                                              smb2req,
 386                                              in_security_mode,
 387                                              in_previous_session_id,
 388                                              in_security_buffer,
 389                                              out_session_flags,
 390                                              out_session_id);
 391 }
 392
 393 static NTSTATUS smbd_smb2_session_setup(struct smbd_smb2_request *smb2req,
 394                                         uint64_t in_session_id,
 395                                         uint8_t in_flags,
 396                                         uint8_t in_security_mode,
 397                                         uint64_t in_previous_session_id,
 398                                         DATA_BLOB in_security_buffer,
 399                                         uint16_t *out_session_flags,
 400                                         DATA_BLOB *out_security_buffer,
 401                                         uint64_t *out_session_id)
 402 {
 403         struct smbXsrv_session *session;
 404         NTSTATUS status;
 405         NTTIME now = timeval_to_nttime(&smb2req->request_time);
 406
 407         *out_session_flags = 0;
 408         *out_session_id = 0;
 409
 410         if (in_session_id == 0) {
 411                 /* create a new session */
 412                 status = smbXsrv_session_create(smb2req->sconn->conn,
 413                                                 now, &session);
 414                 if (!NT_STATUS_IS_OK(status)) {
 415                         return status;
 416                 }
 417         } else {
 418                 status = smb2srv_session_lookup(smb2req->sconn->conn,
 419                                                 in_session_id, now,
 420                                                 &session);
 421                 if (NT_STATUS_IS_OK(status)) {
 422                         return NT_STATUS_REQUEST_NOT_ACCEPTED;
 423                 }
 424                 if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 425                         return status;
 426                 }
 427         }
 428
 429         return smbd_smb2_auth_generic(session,
 430                                       smb2req,
 431                                       in_security_mode,
 432                                       in_previous_session_id,
 433                                       in_security_buffer,
 434                                       out_session_flags,
 435                                       out_security_buffer,
 436                                       out_session_id);
 437 }
 438
 439 struct smbd_smb2_session_setup_state {
 440         struct tevent_context *ev;
 441         struct smbd_smb2_request *smb2req;
 442         uint64_t in_session_id;
 443         uint8_t in_flags;
 444         uint8_t in_security_mode;
 445         uint64_t in_previous_session_id;
 446         DATA_BLOB in_security_buffer;
 447         uint16_t out_session_flags;
 448         DATA_BLOB out_security_buffer;
 449         uint64_t out_session_id;
 450 };
 451
 452 static struct tevent_req *smbd_smb2_session_setup_send(TALLOC_CTX *mem_ctx,
 453                                         struct tevent_context *ev,
 454                                         struct smbd_smb2_request *smb2req,
 455                                         uint64_t in_session_id,
 456                                         uint8_t in_flags,
 457                                         uint8_t in_security_mode,
 458                                         uint64_t in_previous_session_id,
 459                                         DATA_BLOB in_security_buffer)
 460 {
 461         struct tevent_req *req;
 462         struct smbd_smb2_session_setup_state *state;
 463         NTSTATUS status;
 464
 465         req = tevent_req_create(mem_ctx, &state,
 466                                 struct smbd_smb2_session_setup_state);
 467         if (req == NULL) {
 468                 return NULL;
 469         }
 470         state->ev = ev;
 471         state->smb2req = smb2req;
 472         state->in_session_id = in_session_id;
 473         state->in_flags = in_flags;
 474         state->in_security_mode = in_security_mode;
 475         state->in_previous_session_id = in_previous_session_id;
 476         state->in_security_buffer = in_security_buffer;
 477
 478         status = smbd_smb2_session_setup(smb2req,
 479                                          in_session_id,
 480                                          in_flags,
 481                                          in_security_mode,
 482                                          in_previous_session_id,
 483                                          in_security_buffer,
 484                                          &state->out_session_flags,
 485                                          &state->out_security_buffer,
 486                                          &state->out_session_id);
 487         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) ||
 488             NT_STATUS_IS_OK(status))
 489         {
 490                 talloc_steal(state, state->out_security_buffer.data);
 491         }
 492         if (tevent_req_nterror(req, status)) {
 493                 return tevent_req_post(req, ev);
 494         }
 495
 496         tevent_req_done(req);
 497         return tevent_req_post(req, ev);
 498 }
 499
 500 static NTSTATUS smbd_smb2_session_setup_recv(struct tevent_req *req,
 501                                         uint16_t *out_session_flags,
 502                                         TALLOC_CTX *mem_ctx,
 503                                         DATA_BLOB *out_security_buffer,
 504                                         uint64_t *out_session_id)
 505 {
 506         struct smbd_smb2_session_setup_state *state =
 507                 tevent_req_data(req,
 508                 struct smbd_smb2_session_setup_state);
 509         NTSTATUS status;
 510
 511         if (tevent_req_is_nterror(req, &status)) {
 512                 if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 513                         tevent_req_received(req);
 514                         return nt_status_squash(status);
 515                 }
 516         } else {
 517                 status = NT_STATUS_OK;
 518         }
 519
 520         *out_session_flags = state->out_session_flags;
 521         *out_security_buffer = state->out_security_buffer;
 522         *out_session_id = state->out_session_id;
 523
 524         talloc_steal(mem_ctx, out_security_buffer->data);
 525         tevent_req_received(req);
 526         return status;
 527 }
 528
 529 NTSTATUS smbd_smb2_request_process_logoff(struct smbd_smb2_request *req)
 530 {
 531         NTSTATUS status;
 532         DATA_BLOB outbody;
 533
 534         status = smbd_smb2_request_verify_sizes(req, 0x04);
 535         if (!NT_STATUS_IS_OK(status)) {
 536                 return smbd_smb2_request_error(req, status);
 537         }
 538
 539         /*
 540          * TODO: cancel all outstanding requests on the session
 541          */
 542         status = smbXsrv_session_logoff(req->session);
 543         if (!NT_STATUS_IS_OK(status)) {
 544                 DEBUG(0, ("smbd_smb2_request_process_logoff: "
 545                           "smbXsrv_session_logoff() failed: %s\n",
 546                           nt_errstr(status)));
 547                 /*
 548                  * If we hit this case, there is something completely
 549                  * wrong, so we better disconnect the transport connection.
 550                  */
 551                 return status;
 552         }
 553
 554         /*
 555          * we may need to sign the response, so we need to keep
 556          * the session until the response is sent to the wire.
 557          */
 558         talloc_steal(req, req->session);
 559
 560         outbody = data_blob_talloc(req->out.vector, NULL, 0x04);
 561         if (outbody.data == NULL) {
 562                 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 563         }
 564
 565         SSVAL(outbody.data, 0x00, 0x04);        /* struct size */
 566         SSVAL(outbody.data, 0x02, 0);           /* reserved */
 567
 568         return smbd_smb2_request_done(req, outbody, NULL);
 569 }