source3/librpc/rpc/dcerpc_helpers.c

   1 /*
   2  *  DCERPC Helper routines
   3  *  Günther Deschner <gd@samba.org> 2010.
   4  *  Simo Sorce <idra@samba.org> 2010.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20
  21 #include "includes.h"
  22 #include "librpc/rpc/dcerpc.h"
  23 #include "librpc/gen_ndr/ndr_dcerpc.h"
  24 #include "librpc/gen_ndr/ndr_schannel.h"
  25 #include "../libcli/auth/schannel.h"
  26 #include "../libcli/auth/spnego.h"
  27 #include "librpc/crypto/gse.h"
  28 #include "librpc/crypto/spnego.h"
  29 #include "auth/gensec/gensec.h"
  30
  31 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_RPC_PARSE
  33
  34 /**
  35 * @brief NDR Encodes a ncacn_packet
  36 *
  37 * @param mem_ctx        The memory context the blob will be allocated on
  38 * @param ptype          The DCERPC packet type
  39 * @param pfc_flags      The DCERPC PFC Falgs
  40 * @param auth_length    The length of the trailing auth blob
  41 * @param call_id        The call ID
  42 * @param u              The payload of the packet
  43 * @param blob [out]     The encoded blob if successful
  44 *
  45 * @return an NTSTATUS error code
  46 */
  47 NTSTATUS dcerpc_push_ncacn_packet(TALLOC_CTX *mem_ctx,
  48                                   enum dcerpc_pkt_type ptype,
  49                                   uint8_t pfc_flags,
  50                                   uint16_t auth_length,
  51                                   uint32_t call_id,
  52                                   union dcerpc_payload *u,
  53                                   DATA_BLOB *blob)
  54 {
  55         struct ncacn_packet r;
  56         enum ndr_err_code ndr_err;
  57
  58         r.rpc_vers              = 5;
  59         r.rpc_vers_minor        = 0;
  60         r.ptype                 = ptype;
  61         r.pfc_flags             = pfc_flags;
  62         r.drep[0]               = DCERPC_DREP_LE;
  63         r.drep[1]               = 0;
  64         r.drep[2]               = 0;
  65         r.drep[3]               = 0;
  66         r.auth_length           = auth_length;
  67         r.call_id               = call_id;
  68         r.u                     = *u;
  69
  70         ndr_err = ndr_push_struct_blob(blob, mem_ctx, &r,
  71                 (ndr_push_flags_fn_t)ndr_push_ncacn_packet);
  72         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  73                 return ndr_map_error2ntstatus(ndr_err);
  74         }
  75
  76         dcerpc_set_frag_length(blob, blob->length);
  77
  78
  79         if (DEBUGLEVEL >= 10) {
  80                 /* set frag len for print function */
  81                 r.frag_length = blob->length;
  82                 NDR_PRINT_DEBUG(ncacn_packet, &r);
  83         }
  84
  85         return NT_STATUS_OK;
  86 }
  87
  88 /**
  89 * @brief Decodes a ncacn_packet
  90 *
  91 * @param mem_ctx        The memory context on which to allocate the packet
  92 *                       elements
  93 * @param blob           The blob of data to decode
  94 * @param r              An empty ncacn_packet, must not be NULL
  95 * @param bigendian      Whether the packet is bignedian encoded
  96 *
  97 * @return a NTSTATUS error code
  98 */
  99 NTSTATUS dcerpc_pull_ncacn_packet(TALLOC_CTX *mem_ctx,
 100                                   const DATA_BLOB *blob,
 101                                   struct ncacn_packet *r,
 102                                   bool bigendian)
 103 {
 104         enum ndr_err_code ndr_err;
 105         struct ndr_pull *ndr;
 106
 107         ndr = ndr_pull_init_blob(blob, mem_ctx);
 108         if (!ndr) {
 109                 return NT_STATUS_NO_MEMORY;
 110         }
 111         if (bigendian) {
 112                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
 113         }
 114
 115         ndr_err = ndr_pull_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, r);
 116
 117         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 118                 talloc_free(ndr);
 119                 return ndr_map_error2ntstatus(ndr_err);
 120         }
 121         talloc_free(ndr);
 122
 123         if (DEBUGLEVEL >= 10) {
 124                 NDR_PRINT_DEBUG(ncacn_packet, r);
 125         }
 126
 127         return NT_STATUS_OK;
 128 }
 129
 130 /**
 131 * @brief NDR Encodes a NL_AUTH_MESSAGE
 132 *
 133 * @param mem_ctx        The memory context the blob will be allocated on
 134 * @param r              The NL_AUTH_MESSAGE to encode
 135 * @param blob [out]     The encoded blob if successful
 136 *
 137 * @return a NTSTATUS error code
 138 */
 139 NTSTATUS dcerpc_push_schannel_bind(TALLOC_CTX *mem_ctx,
 140                                    struct NL_AUTH_MESSAGE *r,
 141                                    DATA_BLOB *blob)
 142 {
 143         enum ndr_err_code ndr_err;
 144
 145         ndr_err = ndr_push_struct_blob(blob, mem_ctx, r,
 146                 (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
 147         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 148                 return ndr_map_error2ntstatus(ndr_err);
 149         }
 150
 151         if (DEBUGLEVEL >= 10) {
 152                 NDR_PRINT_DEBUG(NL_AUTH_MESSAGE, r);
 153         }
 154
 155         return NT_STATUS_OK;
 156 }
 157
 158 /**
 159 * @brief NDR Encodes a dcerpc_auth structure
 160 *
 161 * @param mem_ctx          The memory context the blob will be allocated on
 162 * @param auth_type        The DCERPC Authentication Type
 163 * @param auth_level       The DCERPC Authentication Level
 164 * @param auth_pad_length  The padding added to the packet this blob will be
 165 *                          appended to.
 166 * @param auth_context_id  The context id
 167 * @param credentials      The authentication credentials blob (signature)
 168 * @param blob [out]       The encoded blob if successful
 169 *
 170 * @return a NTSTATUS error code
 171 */
 172 NTSTATUS dcerpc_push_dcerpc_auth(TALLOC_CTX *mem_ctx,
 173                                  enum dcerpc_AuthType auth_type,
 174                                  enum dcerpc_AuthLevel auth_level,
 175                                  uint8_t auth_pad_length,
 176                                  uint32_t auth_context_id,
 177                                  const DATA_BLOB *credentials,
 178                                  DATA_BLOB *blob)
 179 {
 180         struct dcerpc_auth r;
 181         enum ndr_err_code ndr_err;
 182
 183         r.auth_type             = auth_type;
 184         r.auth_level            = auth_level;
 185         r.auth_pad_length       = auth_pad_length;
 186         r.auth_reserved         = 0;
 187         r.auth_context_id       = auth_context_id;
 188         r.credentials           = *credentials;
 189
 190         ndr_err = ndr_push_struct_blob(blob, mem_ctx, &r,
 191                 (ndr_push_flags_fn_t)ndr_push_dcerpc_auth);
 192         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 193                 return ndr_map_error2ntstatus(ndr_err);
 194         }
 195
 196         if (DEBUGLEVEL >= 10) {
 197                 NDR_PRINT_DEBUG(dcerpc_auth, &r);
 198         }
 199
 200         return NT_STATUS_OK;
 201 }
 202
 203 /**
 204 * @brief Decodes a dcerpc_auth blob
 205 *
 206 * @param mem_ctx        The memory context on which to allocate the packet
 207 *                       elements
 208 * @param blob           The blob of data to decode
 209 * @param r              An empty dcerpc_auth structure, must not be NULL
 210 *
 211 * @return a NTSTATUS error code
 212 */
 213 NTSTATUS dcerpc_pull_dcerpc_auth(TALLOC_CTX *mem_ctx,
 214                                  const DATA_BLOB *blob,
 215                                  struct dcerpc_auth *r,
 216                                  bool bigendian)
 217 {
 218         enum ndr_err_code ndr_err;
 219         struct ndr_pull *ndr;
 220
 221         ndr = ndr_pull_init_blob(blob, mem_ctx);
 222         if (!ndr) {
 223                 return NT_STATUS_NO_MEMORY;
 224         }
 225         if (bigendian) {
 226                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
 227         }
 228
 229         ndr_err = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, r);
 230
 231         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 232                 talloc_free(ndr);
 233                 return ndr_map_error2ntstatus(ndr_err);
 234         }
 235         talloc_free(ndr);
 236
 237         if (DEBUGLEVEL >= 10) {
 238                 NDR_PRINT_DEBUG(dcerpc_auth, r);
 239         }
 240
 241         return NT_STATUS_OK;
 242 }
 243
 244 /**
 245 * @brief Calculate how much data we can in a packet, including calculating
 246 *        auth token and pad lengths.
 247 *
 248 * @param auth           The pipe_auth_data structure for this pipe.
 249 * @param header_len     The length of the packet header
 250 * @param data_left      The data left in the send buffer
 251 * @param max_xmit_frag  The max fragment size.
 252 * @param pad_alignment  The NDR padding size.
 253 * @param data_to_send   [out] The max data we will send in the pdu
 254 * @param frag_len       [out] The total length of the fragment
 255 * @param auth_len       [out] The length of the auth trailer
 256 * @param pad_len        [out] The padding to be applied
 257 *
 258 * @return A NT Error status code.
 259 */
 260 NTSTATUS dcerpc_guess_sizes(struct pipe_auth_data *auth,
 261                             size_t header_len, size_t data_left,
 262                             size_t max_xmit_frag, size_t pad_alignment,
 263                             size_t *data_to_send, size_t *frag_len,
 264                             size_t *auth_len, size_t *pad_len)
 265 {
 266         size_t max_len;
 267         size_t mod_len;
 268         struct gensec_security *gensec_security;
 269         struct schannel_state *schannel_auth;
 270         struct spnego_context *spnego_ctx;
 271         enum spnego_mech auth_type;
 272         NTSTATUS status;
 273
 274         /* no auth token cases first */
 275         switch (auth->auth_level) {
 276         case DCERPC_AUTH_LEVEL_NONE:
 277         case DCERPC_AUTH_LEVEL_CONNECT:
 278         case DCERPC_AUTH_LEVEL_PACKET:
 279                 max_len = max_xmit_frag - header_len;
 280                 *data_to_send = MIN(max_len, data_left);
 281                 *pad_len = 0;
 282                 *auth_len = 0;
 283                 *frag_len = header_len + *data_to_send;
 284                 return NT_STATUS_OK;
 285
 286         case DCERPC_AUTH_LEVEL_PRIVACY:
 287                 break;
 288
 289         case DCERPC_AUTH_LEVEL_INTEGRITY:
 290                 break;
 291
 292         default:
 293                 return NT_STATUS_INVALID_PARAMETER;
 294         }
 295
 296
 297         /* Sign/seal case, calculate auth and pad lengths */
 298
 299         max_len = max_xmit_frag - header_len - DCERPC_AUTH_TRAILER_LENGTH;
 300
 301         /* Treat the same for all authenticated rpc requests. */
 302         switch (auth->auth_type) {
 303         case DCERPC_AUTH_TYPE_SPNEGO:
 304                 spnego_ctx = talloc_get_type_abort(auth->auth_ctx,
 305                                                    struct spnego_context);
 306                 status = spnego_get_negotiated_mech(spnego_ctx,
 307                                                     &auth_type, &gensec_security);
 308                 if (!NT_STATUS_IS_OK(status)) {
 309                         return status;
 310                 }
 311                 *auth_len = gensec_sig_size(gensec_security, max_len);
 312                 break;
 313
 314         case DCERPC_AUTH_TYPE_NTLMSSP:
 315         case DCERPC_AUTH_TYPE_KRB5:
 316                 gensec_security = talloc_get_type_abort(auth->auth_ctx,
 317                                                         struct gensec_security);
 318                 *auth_len = gensec_sig_size(gensec_security, max_len);
 319                 break;
 320
 321         case DCERPC_AUTH_TYPE_SCHANNEL:
 322                 schannel_auth = talloc_get_type_abort(auth->auth_ctx,
 323                                                       struct schannel_state);
 324                 *auth_len = netsec_outgoing_sig_size(schannel_auth);
 325                 break;
 326         default:
 327                 return NT_STATUS_INVALID_PARAMETER;
 328         }
 329
 330         max_len -= *auth_len;
 331
 332         *data_to_send = MIN(max_len, data_left);
 333
 334         mod_len = (header_len + *data_to_send) % pad_alignment;
 335         if (mod_len) {
 336                 *pad_len = pad_alignment - mod_len;
 337         } else {
 338                 *pad_len = 0;
 339         }
 340
 341         if (*data_to_send + *pad_len > max_len) {
 342                 *data_to_send -= pad_alignment;
 343         }
 344
 345         *frag_len = header_len + *data_to_send + *pad_len
 346                         + DCERPC_AUTH_TRAILER_LENGTH + *auth_len;
 347
 348         return NT_STATUS_OK;
 349 }
 350
 351 /*******************************************************************
 352  Create and add the NTLMSSP sign/seal auth data.
 353  ********************************************************************/
 354
 355 static NTSTATUS add_generic_auth_footer(struct gensec_security *gensec_security,
 356                                         enum dcerpc_AuthLevel auth_level,
 357                                         DATA_BLOB *rpc_out)
 358 {
 359         uint16_t data_and_pad_len = rpc_out->length
 360                                         - DCERPC_RESPONSE_LENGTH
 361                                         - DCERPC_AUTH_TRAILER_LENGTH;
 362         DATA_BLOB auth_blob;
 363         NTSTATUS status;
 364
 365         if (!gensec_security) {
 366                 return NT_STATUS_INVALID_PARAMETER;
 367         }
 368
 369         switch (auth_level) {
 370         case DCERPC_AUTH_LEVEL_PRIVACY:
 371                 /* Data portion is encrypted. */
 372                 status = gensec_seal_packet(gensec_security,
 373                                             rpc_out->data,
 374                                             rpc_out->data
 375                                             + DCERPC_RESPONSE_LENGTH,
 376                                             data_and_pad_len,
 377                                             rpc_out->data,
 378                                             rpc_out->length,
 379                                             &auth_blob);
 380                 if (!NT_STATUS_IS_OK(status)) {
 381                         return status;
 382                 }
 383                 break;
 384
 385         case DCERPC_AUTH_LEVEL_INTEGRITY:
 386                 /* Data is signed. */
 387                 status = gensec_sign_packet(gensec_security,
 388                                             rpc_out->data,
 389                                             rpc_out->data
 390                                             + DCERPC_RESPONSE_LENGTH,
 391                                             data_and_pad_len,
 392                                             rpc_out->data,
 393                                             rpc_out->length,
 394                                             &auth_blob);
 395                 if (!NT_STATUS_IS_OK(status)) {
 396                         return status;
 397                 }
 398                 break;
 399
 400         default:
 401                 /* Can't happen. */
 402                 smb_panic("bad auth level");
 403                 /* Notreached. */
 404                 return NT_STATUS_INVALID_PARAMETER;
 405         }
 406
 407         /* Finally attach the blob. */
 408         if (!data_blob_append(NULL, rpc_out,
 409                                 auth_blob.data, auth_blob.length)) {
 410                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 411                           (unsigned int)auth_blob.length));
 412                 return NT_STATUS_NO_MEMORY;
 413         }
 414         data_blob_free(&auth_blob);
 415
 416         return NT_STATUS_OK;
 417 }
 418
 419 /*******************************************************************
 420  Check/unseal the NTLMSSP auth data. (Unseal in place).
 421  ********************************************************************/
 422
 423 static NTSTATUS get_generic_auth_footer(struct gensec_security *gensec_security,
 424                                         enum dcerpc_AuthLevel auth_level,
 425                                         DATA_BLOB *data, DATA_BLOB *full_pkt,
 426                                         DATA_BLOB *auth_token)
 427 {
 428         switch (auth_level) {
 429         case DCERPC_AUTH_LEVEL_PRIVACY:
 430                 /* Data portion is encrypted. */
 431                 return gensec_unseal_packet(gensec_security,
 432                                             data->data,
 433                                             data->length,
 434                                             full_pkt->data,
 435                                             full_pkt->length,
 436                                             auth_token);
 437
 438         case DCERPC_AUTH_LEVEL_INTEGRITY:
 439                 /* Data is signed. */
 440                 return gensec_check_packet(gensec_security,
 441                                            data->data,
 442                                            data->length,
 443                                            full_pkt->data,
 444                                            full_pkt->length,
 445                                            auth_token);
 446
 447         default:
 448                 return NT_STATUS_INVALID_PARAMETER;
 449         }
 450 }
 451
 452 /*******************************************************************
 453  Create and add the schannel sign/seal auth data.
 454  ********************************************************************/
 455
 456 static NTSTATUS add_schannel_auth_footer(struct schannel_state *sas,
 457                                         enum dcerpc_AuthLevel auth_level,
 458                                         DATA_BLOB *rpc_out)
 459 {
 460         uint8_t *data_p = rpc_out->data + DCERPC_RESPONSE_LENGTH;
 461         size_t data_and_pad_len = rpc_out->length
 462                                         - DCERPC_RESPONSE_LENGTH
 463                                         - DCERPC_AUTH_TRAILER_LENGTH;
 464         DATA_BLOB auth_blob;
 465         NTSTATUS status;
 466
 467         if (!sas) {
 468                 return NT_STATUS_INVALID_PARAMETER;
 469         }
 470
 471         DEBUG(10,("add_schannel_auth_footer: SCHANNEL seq_num=%d\n",
 472                         sas->seq_num));
 473
 474         switch (auth_level) {
 475         case DCERPC_AUTH_LEVEL_PRIVACY:
 476                 status = netsec_outgoing_packet(sas,
 477                                                 rpc_out->data,
 478                                                 true,
 479                                                 data_p,
 480                                                 data_and_pad_len,
 481                                                 &auth_blob);
 482                 break;
 483         case DCERPC_AUTH_LEVEL_INTEGRITY:
 484                 status = netsec_outgoing_packet(sas,
 485                                                 rpc_out->data,
 486                                                 false,
 487                                                 data_p,
 488                                                 data_and_pad_len,
 489                                                 &auth_blob);
 490                 break;
 491         default:
 492                 status = NT_STATUS_INTERNAL_ERROR;
 493                 break;
 494         }
 495
 496         if (!NT_STATUS_IS_OK(status)) {
 497                 DEBUG(1,("add_schannel_auth_footer: failed to process packet: %s\n",
 498                         nt_errstr(status)));
 499                 return status;
 500         }
 501
 502         if (DEBUGLEVEL >= 10) {
 503                 dump_NL_AUTH_SIGNATURE(talloc_tos(), &auth_blob);
 504         }
 505
 506         /* Finally attach the blob. */
 507         if (!data_blob_append(NULL, rpc_out,
 508                                 auth_blob.data, auth_blob.length)) {
 509                 return NT_STATUS_NO_MEMORY;
 510         }
 511         data_blob_free(&auth_blob);
 512
 513         return NT_STATUS_OK;
 514 }
 515
 516 /*******************************************************************
 517  Check/unseal the Schannel auth data. (Unseal in place).
 518  ********************************************************************/
 519
 520 static NTSTATUS get_schannel_auth_footer(TALLOC_CTX *mem_ctx,
 521                                          struct schannel_state *auth_state,
 522                                          enum dcerpc_AuthLevel auth_level,
 523                                          DATA_BLOB *data, DATA_BLOB *full_pkt,
 524                                          DATA_BLOB *auth_token)
 525 {
 526         switch (auth_level) {
 527         case DCERPC_AUTH_LEVEL_PRIVACY:
 528                 /* Data portion is encrypted. */
 529                 return netsec_incoming_packet(auth_state,
 530                                                 true,
 531                                                 data->data,
 532                                                 data->length,
 533                                                 auth_token);
 534
 535         case DCERPC_AUTH_LEVEL_INTEGRITY:
 536                 /* Data is signed. */
 537                 return netsec_incoming_packet(auth_state,
 538                                                 false,
 539                                                 data->data,
 540                                                 data->length,
 541                                                 auth_token);
 542
 543         default:
 544                 return NT_STATUS_INVALID_PARAMETER;
 545         }
 546 }
 547
 548 /*******************************************************************
 549  Create and add the spnego-negotiated sign/seal auth data.
 550  ********************************************************************/
 551
 552 static NTSTATUS add_spnego_auth_footer(struct spnego_context *spnego_ctx,
 553                                         enum dcerpc_AuthLevel auth_level,
 554                                         DATA_BLOB *rpc_out)
 555 {
 556         DATA_BLOB auth_blob;
 557         DATA_BLOB rpc_data;
 558         NTSTATUS status;
 559
 560         if (!spnego_ctx) {
 561                 return NT_STATUS_INVALID_PARAMETER;
 562         }
 563
 564         rpc_data = data_blob_const(rpc_out->data
 565                                         + DCERPC_RESPONSE_LENGTH,
 566                                    rpc_out->length
 567                                         - DCERPC_RESPONSE_LENGTH
 568                                         - DCERPC_AUTH_TRAILER_LENGTH);
 569
 570         switch (auth_level) {
 571         case DCERPC_AUTH_LEVEL_PRIVACY:
 572                 /* Data portion is encrypted. */
 573                 status = spnego_seal(rpc_out->data, spnego_ctx,
 574                                      &rpc_data, rpc_out, &auth_blob);
 575                 break;
 576
 577                 if (!NT_STATUS_IS_OK(status)) {
 578                         return status;
 579                 }
 580                 break;
 581
 582         case DCERPC_AUTH_LEVEL_INTEGRITY:
 583                 /* Data is signed. */
 584                 status = spnego_sign(rpc_out->data, spnego_ctx,
 585                                      &rpc_data, rpc_out, &auth_blob);
 586                 break;
 587
 588                 if (!NT_STATUS_IS_OK(status)) {
 589                         return status;
 590                 }
 591                 break;
 592
 593         default:
 594                 /* Can't happen. */
 595                 smb_panic("bad auth level");
 596                 /* Notreached. */
 597                 return NT_STATUS_INVALID_PARAMETER;
 598         }
 599
 600         /* Finally attach the blob. */
 601         if (!data_blob_append(NULL, rpc_out,
 602                                 auth_blob.data, auth_blob.length)) {
 603                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 604                           (unsigned int)auth_blob.length));
 605                 return NT_STATUS_NO_MEMORY;
 606         }
 607         data_blob_free(&auth_blob);
 608
 609         return NT_STATUS_OK;
 610 }
 611
 612 static NTSTATUS get_spnego_auth_footer(TALLOC_CTX *mem_ctx,
 613                                         struct spnego_context *sp_ctx,
 614                                         enum dcerpc_AuthLevel auth_level,
 615                                         DATA_BLOB *data, DATA_BLOB *full_pkt,
 616                                         DATA_BLOB *auth_token)
 617 {
 618         switch (auth_level) {
 619         case DCERPC_AUTH_LEVEL_PRIVACY:
 620                 /* Data portion is encrypted. */
 621                 return spnego_unseal(mem_ctx, sp_ctx,
 622                                      data, full_pkt, auth_token);
 623
 624         case DCERPC_AUTH_LEVEL_INTEGRITY:
 625                 /* Data is signed. */
 626                 return spnego_sigcheck(mem_ctx, sp_ctx,
 627                                        data, full_pkt, auth_token);
 628
 629         default:
 630                 return NT_STATUS_INVALID_PARAMETER;
 631         }
 632 }
 633
 634 /**
 635 * @brief   Append an auth footer according to what is the current mechanism
 636 *
 637 * @param auth           The pipe_auth_data associated with the connection
 638 * @param pad_len        The padding used in the packet
 639 * @param rpc_out        Packet blob up to and including the auth header
 640 *
 641 * @return A NTSTATUS error code.
 642 */
 643 NTSTATUS dcerpc_add_auth_footer(struct pipe_auth_data *auth,
 644                                 size_t pad_len, DATA_BLOB *rpc_out)
 645 {
 646         struct schannel_state *schannel_auth;
 647         struct gensec_security *gensec_security;
 648         struct spnego_context *spnego_ctx;
 649         char pad[CLIENT_NDR_PADDING_SIZE] = { 0, };
 650         DATA_BLOB auth_info;
 651         DATA_BLOB auth_blob;
 652         NTSTATUS status;
 653
 654         if (auth->auth_type == DCERPC_AUTH_TYPE_NONE ||
 655             auth->auth_type == DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM) {
 656                 return NT_STATUS_OK;
 657         }
 658
 659         if (pad_len) {
 660                 /* Copy the sign/seal padding data. */
 661                 if (!data_blob_append(NULL, rpc_out, pad, pad_len)) {
 662                         return NT_STATUS_NO_MEMORY;
 663                 }
 664         }
 665
 666         /* marshall the dcerpc_auth with an actually empty auth_blob.
 667          * This is needed because the ntmlssp signature includes the
 668          * auth header. We will append the actual blob later. */
 669         auth_blob = data_blob_null;
 670         status = dcerpc_push_dcerpc_auth(rpc_out->data,
 671                                          auth->auth_type,
 672                                          auth->auth_level,
 673                                          pad_len,
 674                                          1 /* context id. */,
 675                                          &auth_blob,
 676                                          &auth_info);
 677         if (!NT_STATUS_IS_OK(status)) {
 678                 return status;
 679         }
 680
 681         /* append the header */
 682         if (!data_blob_append(NULL, rpc_out,
 683                                 auth_info.data, auth_info.length)) {
 684                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 685                           (unsigned int)auth_info.length));
 686                 return NT_STATUS_NO_MEMORY;
 687         }
 688         data_blob_free(&auth_info);
 689
 690         /* Generate any auth sign/seal and add the auth footer. */
 691         switch (auth->auth_type) {
 692         case DCERPC_AUTH_TYPE_NONE:
 693         case DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM:
 694                 status = NT_STATUS_OK;
 695                 break;
 696         case DCERPC_AUTH_TYPE_SPNEGO:
 697                 spnego_ctx = talloc_get_type_abort(auth->auth_ctx,
 698                                                    struct spnego_context);
 699                 status = add_spnego_auth_footer(spnego_ctx,
 700                                                 auth->auth_level, rpc_out);
 701                 break;
 702         case DCERPC_AUTH_TYPE_KRB5:
 703         case DCERPC_AUTH_TYPE_NTLMSSP:
 704                 gensec_security = talloc_get_type_abort(auth->auth_ctx,
 705                                                 struct gensec_security);
 706                 status = add_generic_auth_footer(gensec_security,
 707                                                  auth->auth_level,
 708                                                  rpc_out);
 709                 break;
 710         case DCERPC_AUTH_TYPE_SCHANNEL:
 711                 schannel_auth = talloc_get_type_abort(auth->auth_ctx,
 712                                                       struct schannel_state);
 713                 status = add_schannel_auth_footer(schannel_auth,
 714                                                   auth->auth_level,
 715                                                   rpc_out);
 716                 break;
 717         default:
 718                 status = NT_STATUS_INVALID_PARAMETER;
 719                 break;
 720         }
 721
 722         return status;
 723 }
 724
 725 /**
 726 * @brief Check authentication for request/response packets
 727 *
 728 * @param auth           The auth data for the connection
 729 * @param pkt            The actual ncacn_packet
 730 * @param pkt_trailer    The stub_and_verifier part of the packet
 731 * @param header_size    The header size
 732 * @param raw_pkt        The whole raw packet data blob
 733 * @param pad_len        [out] The padding length used in the packet
 734 *
 735 * @return A NTSTATUS error code
 736 */
 737 NTSTATUS dcerpc_check_auth(struct pipe_auth_data *auth,
 738                            struct ncacn_packet *pkt,
 739                            DATA_BLOB *pkt_trailer,
 740                            size_t header_size,
 741                            DATA_BLOB *raw_pkt,
 742                            size_t *pad_len)
 743 {
 744         struct schannel_state *schannel_auth;
 745         struct gensec_security *gensec_security;
 746         struct spnego_context *spnego_ctx;
 747         NTSTATUS status;
 748         struct dcerpc_auth auth_info;
 749         uint32_t auth_length;
 750         DATA_BLOB full_pkt;
 751         DATA_BLOB data;
 752
 753         switch (auth->auth_level) {
 754         case DCERPC_AUTH_LEVEL_PRIVACY:
 755                 DEBUG(10, ("Requested Privacy.\n"));
 756                 break;
 757
 758         case DCERPC_AUTH_LEVEL_INTEGRITY:
 759                 DEBUG(10, ("Requested Integrity.\n"));
 760                 break;
 761
 762         case DCERPC_AUTH_LEVEL_CONNECT:
 763                 if (pkt->auth_length != 0) {
 764                         break;
 765                 }
 766                 *pad_len = 0;
 767                 return NT_STATUS_OK;
 768
 769         case DCERPC_AUTH_LEVEL_NONE:
 770                 if (pkt->auth_length != 0) {
 771                         DEBUG(3, ("Got non-zero auth len on non "
 772                                   "authenticated connection!\n"));
 773                         return NT_STATUS_INVALID_PARAMETER;
 774                 }
 775                 *pad_len = 0;
 776                 return NT_STATUS_OK;
 777
 778         default:
 779                 DEBUG(3, ("Unimplemented Auth Level %d",
 780                           auth->auth_level));
 781                 return NT_STATUS_INVALID_PARAMETER;
 782         }
 783
 784         /* Paranioa checks for auth_length. */
 785         if (pkt->auth_length > pkt->frag_length) {
 786                 return NT_STATUS_INFO_LENGTH_MISMATCH;
 787         }
 788         if (((unsigned int)pkt->auth_length
 789              + DCERPC_AUTH_TRAILER_LENGTH < (unsigned int)pkt->auth_length) ||
 790             ((unsigned int)pkt->auth_length
 791              + DCERPC_AUTH_TRAILER_LENGTH < DCERPC_AUTH_TRAILER_LENGTH)) {
 792                 /* Integer wrap attempt. */
 793                 return NT_STATUS_INFO_LENGTH_MISMATCH;
 794         }
 795
 796         status = dcerpc_pull_auth_trailer(pkt, pkt, pkt_trailer,
 797                                           &auth_info, &auth_length, false);
 798         if (!NT_STATUS_IS_OK(status)) {
 799                 return status;
 800         }
 801
 802         data = data_blob_const(raw_pkt->data + header_size,
 803                                 pkt_trailer->length - auth_length);
 804         full_pkt = data_blob_const(raw_pkt->data,
 805                                 raw_pkt->length - auth_info.credentials.length);
 806
 807         switch (auth->auth_type) {
 808         case DCERPC_AUTH_TYPE_NONE:
 809         case DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM:
 810                 return NT_STATUS_OK;
 811
 812         case DCERPC_AUTH_TYPE_SPNEGO:
 813                 spnego_ctx = talloc_get_type_abort(auth->auth_ctx,
 814                                                    struct spnego_context);
 815                 status = get_spnego_auth_footer(pkt, spnego_ctx,
 816                                                 auth->auth_level,
 817                                                 &data, &full_pkt,
 818                                                 &auth_info.credentials);
 819                 if (!NT_STATUS_IS_OK(status)) {
 820                         return status;
 821                 }
 822                 break;
 823
 824         case DCERPC_AUTH_TYPE_KRB5:
 825         case DCERPC_AUTH_TYPE_NTLMSSP:
 826
 827                 DEBUG(10, ("GENSEC auth\n"));
 828
 829                 gensec_security = talloc_get_type_abort(auth->auth_ctx,
 830                                                 struct gensec_security);
 831                 status = get_generic_auth_footer(gensec_security,
 832                                                  auth->auth_level,
 833                                                  &data, &full_pkt,
 834                                                  &auth_info.credentials);
 835                 if (!NT_STATUS_IS_OK(status)) {
 836                         return status;
 837                 }
 838                 break;
 839
 840         case DCERPC_AUTH_TYPE_SCHANNEL:
 841
 842                 DEBUG(10, ("SCHANNEL auth\n"));
 843
 844                 schannel_auth = talloc_get_type_abort(auth->auth_ctx,
 845                                                       struct schannel_state);
 846                 status = get_schannel_auth_footer(pkt, schannel_auth,
 847                                                   auth->auth_level,
 848                                                   &data, &full_pkt,
 849                                                   &auth_info.credentials);
 850                 if (!NT_STATUS_IS_OK(status)) {
 851                         return status;
 852                 }
 853                 break;
 854
 855         default:
 856                 DEBUG(0, ("process_request_pdu: "
 857                           "unknown auth type %u set.\n",
 858                           (unsigned int)auth->auth_type));
 859                 return NT_STATUS_INVALID_PARAMETER;
 860         }
 861
 862         /* TODO: remove later
 863          * this is still needed because in the server code the
 864          * pkt_trailer actually has a copy of the raw data, and they
 865          * are still both used in later calls */
 866         if (auth->auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
 867                 memcpy(pkt_trailer->data, data.data, data.length);
 868         }
 869
 870         *pad_len = auth_info.auth_pad_length;
 871         data_blob_free(&auth_info.credentials);
 872         return NT_STATUS_OK;
 873 }
 874