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         NTSTATUS status;
 272
 273         /* no auth token cases first */
 274         switch (auth->auth_level) {
 275         case DCERPC_AUTH_LEVEL_NONE:
 276         case DCERPC_AUTH_LEVEL_CONNECT:
 277         case DCERPC_AUTH_LEVEL_PACKET:
 278                 max_len = max_xmit_frag - header_len;
 279                 *data_to_send = MIN(max_len, data_left);
 280                 *pad_len = 0;
 281                 *auth_len = 0;
 282                 *frag_len = header_len + *data_to_send;
 283                 return NT_STATUS_OK;
 284
 285         case DCERPC_AUTH_LEVEL_PRIVACY:
 286                 break;
 287
 288         case DCERPC_AUTH_LEVEL_INTEGRITY:
 289                 break;
 290
 291         default:
 292                 return NT_STATUS_INVALID_PARAMETER;
 293         }
 294
 295
 296         /* Sign/seal case, calculate auth and pad lengths */
 297
 298         max_len = max_xmit_frag - header_len - DCERPC_AUTH_TRAILER_LENGTH;
 299
 300         /* Treat the same for all authenticated rpc requests. */
 301         switch (auth->auth_type) {
 302         case DCERPC_AUTH_TYPE_SPNEGO:
 303                 spnego_ctx = talloc_get_type_abort(auth->auth_ctx,
 304                                                    struct spnego_context);
 305                 status = spnego_get_negotiated_mech(spnego_ctx, &gensec_security);
 306                 if (!NT_STATUS_IS_OK(status)) {
 307                         return status;
 308                 }
 309                 *auth_len = gensec_sig_size(gensec_security, max_len);
 310                 break;
 311
 312         case DCERPC_AUTH_TYPE_NTLMSSP:
 313         case DCERPC_AUTH_TYPE_KRB5:
 314                 gensec_security = talloc_get_type_abort(auth->auth_ctx,
 315                                                         struct gensec_security);
 316                 *auth_len = gensec_sig_size(gensec_security, max_len);
 317                 break;
 318
 319         case DCERPC_AUTH_TYPE_SCHANNEL:
 320                 schannel_auth = talloc_get_type_abort(auth->auth_ctx,
 321                                                       struct schannel_state);
 322                 *auth_len = netsec_outgoing_sig_size(schannel_auth);
 323                 break;
 324         default:
 325                 return NT_STATUS_INVALID_PARAMETER;
 326         }
 327
 328         max_len -= *auth_len;
 329
 330         *data_to_send = MIN(max_len, data_left);
 331
 332         mod_len = (header_len + *data_to_send) % pad_alignment;
 333         if (mod_len) {
 334                 *pad_len = pad_alignment - mod_len;
 335         } else {
 336                 *pad_len = 0;
 337         }
 338
 339         if (*data_to_send + *pad_len > max_len) {
 340                 *data_to_send -= pad_alignment;
 341         }
 342
 343         *frag_len = header_len + *data_to_send + *pad_len
 344                         + DCERPC_AUTH_TRAILER_LENGTH + *auth_len;
 345
 346         return NT_STATUS_OK;
 347 }
 348
 349 /*******************************************************************
 350  Create and add the NTLMSSP sign/seal auth data.
 351  ********************************************************************/
 352
 353 static NTSTATUS add_generic_auth_footer(struct gensec_security *gensec_security,
 354                                         enum dcerpc_AuthLevel auth_level,
 355                                         DATA_BLOB *rpc_out)
 356 {
 357         uint16_t data_and_pad_len = rpc_out->length
 358                                         - DCERPC_RESPONSE_LENGTH
 359                                         - DCERPC_AUTH_TRAILER_LENGTH;
 360         DATA_BLOB auth_blob;
 361         NTSTATUS status;
 362
 363         if (!gensec_security) {
 364                 return NT_STATUS_INVALID_PARAMETER;
 365         }
 366
 367         switch (auth_level) {
 368         case DCERPC_AUTH_LEVEL_PRIVACY:
 369                 /* Data portion is encrypted. */
 370                 status = gensec_seal_packet(gensec_security,
 371                                             rpc_out->data,
 372                                             rpc_out->data
 373                                             + DCERPC_RESPONSE_LENGTH,
 374                                             data_and_pad_len,
 375                                             rpc_out->data,
 376                                             rpc_out->length,
 377                                             &auth_blob);
 378                 if (!NT_STATUS_IS_OK(status)) {
 379                         return status;
 380                 }
 381                 break;
 382
 383         case DCERPC_AUTH_LEVEL_INTEGRITY:
 384                 /* Data is signed. */
 385                 status = gensec_sign_packet(gensec_security,
 386                                             rpc_out->data,
 387                                             rpc_out->data
 388                                             + DCERPC_RESPONSE_LENGTH,
 389                                             data_and_pad_len,
 390                                             rpc_out->data,
 391                                             rpc_out->length,
 392                                             &auth_blob);
 393                 if (!NT_STATUS_IS_OK(status)) {
 394                         return status;
 395                 }
 396                 break;
 397
 398         default:
 399                 /* Can't happen. */
 400                 smb_panic("bad auth level");
 401                 /* Notreached. */
 402                 return NT_STATUS_INVALID_PARAMETER;
 403         }
 404
 405         /* Finally attach the blob. */
 406         if (!data_blob_append(NULL, rpc_out,
 407                                 auth_blob.data, auth_blob.length)) {
 408                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 409                           (unsigned int)auth_blob.length));
 410                 return NT_STATUS_NO_MEMORY;
 411         }
 412         data_blob_free(&auth_blob);
 413
 414         return NT_STATUS_OK;
 415 }
 416
 417 /*******************************************************************
 418  Check/unseal the NTLMSSP auth data. (Unseal in place).
 419  ********************************************************************/
 420
 421 static NTSTATUS get_generic_auth_footer(struct gensec_security *gensec_security,
 422                                         enum dcerpc_AuthLevel auth_level,
 423                                         DATA_BLOB *data, DATA_BLOB *full_pkt,
 424                                         DATA_BLOB *auth_token)
 425 {
 426         switch (auth_level) {
 427         case DCERPC_AUTH_LEVEL_PRIVACY:
 428                 /* Data portion is encrypted. */
 429                 return gensec_unseal_packet(gensec_security,
 430                                             data->data,
 431                                             data->length,
 432                                             full_pkt->data,
 433                                             full_pkt->length,
 434                                             auth_token);
 435
 436         case DCERPC_AUTH_LEVEL_INTEGRITY:
 437                 /* Data is signed. */
 438                 return gensec_check_packet(gensec_security,
 439                                            data->data,
 440                                            data->length,
 441                                            full_pkt->data,
 442                                            full_pkt->length,
 443                                            auth_token);
 444
 445         default:
 446                 return NT_STATUS_INVALID_PARAMETER;
 447         }
 448 }
 449
 450 /*******************************************************************
 451  Create and add the schannel sign/seal auth data.
 452  ********************************************************************/
 453
 454 static NTSTATUS add_schannel_auth_footer(struct schannel_state *sas,
 455                                         enum dcerpc_AuthLevel auth_level,
 456                                         DATA_BLOB *rpc_out)
 457 {
 458         uint8_t *data_p = rpc_out->data + DCERPC_RESPONSE_LENGTH;
 459         size_t data_and_pad_len = rpc_out->length
 460                                         - DCERPC_RESPONSE_LENGTH
 461                                         - DCERPC_AUTH_TRAILER_LENGTH;
 462         DATA_BLOB auth_blob;
 463         NTSTATUS status;
 464
 465         if (!sas) {
 466                 return NT_STATUS_INVALID_PARAMETER;
 467         }
 468
 469         DEBUG(10,("add_schannel_auth_footer: SCHANNEL seq_num=%d\n",
 470                         sas->seq_num));
 471
 472         switch (auth_level) {
 473         case DCERPC_AUTH_LEVEL_PRIVACY:
 474                 status = netsec_outgoing_packet(sas,
 475                                                 rpc_out->data,
 476                                                 true,
 477                                                 data_p,
 478                                                 data_and_pad_len,
 479                                                 &auth_blob);
 480                 break;
 481         case DCERPC_AUTH_LEVEL_INTEGRITY:
 482                 status = netsec_outgoing_packet(sas,
 483                                                 rpc_out->data,
 484                                                 false,
 485                                                 data_p,
 486                                                 data_and_pad_len,
 487                                                 &auth_blob);
 488                 break;
 489         default:
 490                 status = NT_STATUS_INTERNAL_ERROR;
 491                 break;
 492         }
 493
 494         if (!NT_STATUS_IS_OK(status)) {
 495                 DEBUG(1,("add_schannel_auth_footer: failed to process packet: %s\n",
 496                         nt_errstr(status)));
 497                 return status;
 498         }
 499
 500         if (DEBUGLEVEL >= 10) {
 501                 dump_NL_AUTH_SIGNATURE(talloc_tos(), &auth_blob);
 502         }
 503
 504         /* Finally attach the blob. */
 505         if (!data_blob_append(NULL, rpc_out,
 506                                 auth_blob.data, auth_blob.length)) {
 507                 return NT_STATUS_NO_MEMORY;
 508         }
 509         data_blob_free(&auth_blob);
 510
 511         return NT_STATUS_OK;
 512 }
 513
 514 /*******************************************************************
 515  Check/unseal the Schannel auth data. (Unseal in place).
 516  ********************************************************************/
 517
 518 static NTSTATUS get_schannel_auth_footer(TALLOC_CTX *mem_ctx,
 519                                          struct schannel_state *auth_state,
 520                                          enum dcerpc_AuthLevel auth_level,
 521                                          DATA_BLOB *data, DATA_BLOB *full_pkt,
 522                                          DATA_BLOB *auth_token)
 523 {
 524         switch (auth_level) {
 525         case DCERPC_AUTH_LEVEL_PRIVACY:
 526                 /* Data portion is encrypted. */
 527                 return netsec_incoming_packet(auth_state,
 528                                                 true,
 529                                                 data->data,
 530                                                 data->length,
 531                                                 auth_token);
 532
 533         case DCERPC_AUTH_LEVEL_INTEGRITY:
 534                 /* Data is signed. */
 535                 return netsec_incoming_packet(auth_state,
 536                                                 false,
 537                                                 data->data,
 538                                                 data->length,
 539                                                 auth_token);
 540
 541         default:
 542                 return NT_STATUS_INVALID_PARAMETER;
 543         }
 544 }
 545
 546 /**
 547 * @brief   Append an auth footer according to what is the current mechanism
 548 *
 549 * @param auth           The pipe_auth_data associated with the connection
 550 * @param pad_len        The padding used in the packet
 551 * @param rpc_out        Packet blob up to and including the auth header
 552 *
 553 * @return A NTSTATUS error code.
 554 */
 555 NTSTATUS dcerpc_add_auth_footer(struct pipe_auth_data *auth,
 556                                 size_t pad_len, DATA_BLOB *rpc_out)
 557 {
 558         struct schannel_state *schannel_auth;
 559         struct gensec_security *gensec_security;
 560         struct spnego_context *spnego_ctx;
 561         char pad[CLIENT_NDR_PADDING_SIZE] = { 0, };
 562         DATA_BLOB auth_info;
 563         DATA_BLOB auth_blob;
 564         NTSTATUS status;
 565
 566         if (auth->auth_type == DCERPC_AUTH_TYPE_NONE ||
 567             auth->auth_type == DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM) {
 568                 return NT_STATUS_OK;
 569         }
 570
 571         if (pad_len) {
 572                 /* Copy the sign/seal padding data. */
 573                 if (!data_blob_append(NULL, rpc_out, pad, pad_len)) {
 574                         return NT_STATUS_NO_MEMORY;
 575                 }
 576         }
 577
 578         /* marshall the dcerpc_auth with an actually empty auth_blob.
 579          * This is needed because the ntmlssp signature includes the
 580          * auth header. We will append the actual blob later. */
 581         auth_blob = data_blob_null;
 582         status = dcerpc_push_dcerpc_auth(rpc_out->data,
 583                                          auth->auth_type,
 584                                          auth->auth_level,
 585                                          pad_len,
 586                                          1 /* context id. */,
 587                                          &auth_blob,
 588                                          &auth_info);
 589         if (!NT_STATUS_IS_OK(status)) {
 590                 return status;
 591         }
 592
 593         /* append the header */
 594         if (!data_blob_append(NULL, rpc_out,
 595                                 auth_info.data, auth_info.length)) {
 596                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 597                           (unsigned int)auth_info.length));
 598                 return NT_STATUS_NO_MEMORY;
 599         }
 600         data_blob_free(&auth_info);
 601
 602         /* Generate any auth sign/seal and add the auth footer. */
 603         switch (auth->auth_type) {
 604         case DCERPC_AUTH_TYPE_NONE:
 605         case DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM:
 606                 status = NT_STATUS_OK;
 607                 break;
 608         case DCERPC_AUTH_TYPE_SPNEGO:
 609                 spnego_ctx = talloc_get_type_abort(auth->auth_ctx,
 610                                                    struct spnego_context);
 611                 status = spnego_get_negotiated_mech(spnego_ctx, &gensec_security);
 612                 if (!NT_STATUS_IS_OK(status)) {
 613                         return status;
 614                 }
 615
 616                 status = add_generic_auth_footer(gensec_security,
 617                                                  auth->auth_level,
 618                                                  rpc_out);
 619                 break;
 620         case DCERPC_AUTH_TYPE_KRB5:
 621         case DCERPC_AUTH_TYPE_NTLMSSP:
 622                 gensec_security = talloc_get_type_abort(auth->auth_ctx,
 623                                                 struct gensec_security);
 624                 status = add_generic_auth_footer(gensec_security,
 625                                                  auth->auth_level,
 626                                                  rpc_out);
 627                 break;
 628         case DCERPC_AUTH_TYPE_SCHANNEL:
 629                 schannel_auth = talloc_get_type_abort(auth->auth_ctx,
 630                                                       struct schannel_state);
 631                 status = add_schannel_auth_footer(schannel_auth,
 632                                                   auth->auth_level,
 633                                                   rpc_out);
 634                 break;
 635         default:
 636                 status = NT_STATUS_INVALID_PARAMETER;
 637                 break;
 638         }
 639
 640         return status;
 641 }
 642
 643 /**
 644 * @brief Check authentication for request/response packets
 645 *
 646 * @param auth           The auth data for the connection
 647 * @param pkt            The actual ncacn_packet
 648 * @param pkt_trailer    The stub_and_verifier part of the packet
 649 * @param header_size    The header size
 650 * @param raw_pkt        The whole raw packet data blob
 651 * @param pad_len        [out] The padding length used in the packet
 652 *
 653 * @return A NTSTATUS error code
 654 */
 655 NTSTATUS dcerpc_check_auth(struct pipe_auth_data *auth,
 656                            struct ncacn_packet *pkt,
 657                            DATA_BLOB *pkt_trailer,
 658                            size_t header_size,
 659                            DATA_BLOB *raw_pkt,
 660                            size_t *pad_len)
 661 {
 662         struct schannel_state *schannel_auth;
 663         struct gensec_security *gensec_security;
 664         struct spnego_context *spnego_ctx;
 665         NTSTATUS status;
 666         struct dcerpc_auth auth_info;
 667         uint32_t auth_length;
 668         DATA_BLOB full_pkt;
 669         DATA_BLOB data;
 670
 671         switch (auth->auth_level) {
 672         case DCERPC_AUTH_LEVEL_PRIVACY:
 673                 DEBUG(10, ("Requested Privacy.\n"));
 674                 break;
 675
 676         case DCERPC_AUTH_LEVEL_INTEGRITY:
 677                 DEBUG(10, ("Requested Integrity.\n"));
 678                 break;
 679
 680         case DCERPC_AUTH_LEVEL_CONNECT:
 681                 if (pkt->auth_length != 0) {
 682                         break;
 683                 }
 684                 *pad_len = 0;
 685                 return NT_STATUS_OK;
 686
 687         case DCERPC_AUTH_LEVEL_NONE:
 688                 if (pkt->auth_length != 0) {
 689                         DEBUG(3, ("Got non-zero auth len on non "
 690                                   "authenticated connection!\n"));
 691                         return NT_STATUS_INVALID_PARAMETER;
 692                 }
 693                 *pad_len = 0;
 694                 return NT_STATUS_OK;
 695
 696         default:
 697                 DEBUG(3, ("Unimplemented Auth Level %d",
 698                           auth->auth_level));
 699                 return NT_STATUS_INVALID_PARAMETER;
 700         }
 701
 702         /* Paranioa checks for auth_length. */
 703         if (pkt->auth_length > pkt->frag_length) {
 704                 return NT_STATUS_INFO_LENGTH_MISMATCH;
 705         }
 706         if (((unsigned int)pkt->auth_length
 707              + DCERPC_AUTH_TRAILER_LENGTH < (unsigned int)pkt->auth_length) ||
 708             ((unsigned int)pkt->auth_length
 709              + DCERPC_AUTH_TRAILER_LENGTH < DCERPC_AUTH_TRAILER_LENGTH)) {
 710                 /* Integer wrap attempt. */
 711                 return NT_STATUS_INFO_LENGTH_MISMATCH;
 712         }
 713
 714         status = dcerpc_pull_auth_trailer(pkt, pkt, pkt_trailer,
 715                                           &auth_info, &auth_length, false);
 716         if (!NT_STATUS_IS_OK(status)) {
 717                 return status;
 718         }
 719
 720         data = data_blob_const(raw_pkt->data + header_size,
 721                                 pkt_trailer->length - auth_length);
 722         full_pkt = data_blob_const(raw_pkt->data,
 723                                 raw_pkt->length - auth_info.credentials.length);
 724
 725         switch (auth->auth_type) {
 726         case DCERPC_AUTH_TYPE_NONE:
 727         case DCERPC_AUTH_TYPE_NCALRPC_AS_SYSTEM:
 728                 return NT_STATUS_OK;
 729
 730         case DCERPC_AUTH_TYPE_SPNEGO:
 731                 spnego_ctx = talloc_get_type_abort(auth->auth_ctx,
 732                                                    struct spnego_context);
 733                 status = spnego_get_negotiated_mech(spnego_ctx, &gensec_security);
 734                 if (!NT_STATUS_IS_OK(status)) {
 735                         return status;
 736                 }
 737
 738                 status = get_generic_auth_footer(gensec_security,
 739                                                  auth->auth_level,
 740                                                  &data, &full_pkt,
 741                                                  &auth_info.credentials);
 742
 743                 if (!NT_STATUS_IS_OK(status)) {
 744                         return status;
 745                 }
 746                 break;
 747
 748         case DCERPC_AUTH_TYPE_KRB5:
 749         case DCERPC_AUTH_TYPE_NTLMSSP:
 750
 751                 DEBUG(10, ("GENSEC auth\n"));
 752
 753                 gensec_security = talloc_get_type_abort(auth->auth_ctx,
 754                                                 struct gensec_security);
 755                 status = get_generic_auth_footer(gensec_security,
 756                                                  auth->auth_level,
 757                                                  &data, &full_pkt,
 758                                                  &auth_info.credentials);
 759                 if (!NT_STATUS_IS_OK(status)) {
 760                         return status;
 761                 }
 762                 break;
 763
 764         case DCERPC_AUTH_TYPE_SCHANNEL:
 765
 766                 DEBUG(10, ("SCHANNEL auth\n"));
 767
 768                 schannel_auth = talloc_get_type_abort(auth->auth_ctx,
 769                                                       struct schannel_state);
 770                 status = get_schannel_auth_footer(pkt, schannel_auth,
 771                                                   auth->auth_level,
 772                                                   &data, &full_pkt,
 773                                                   &auth_info.credentials);
 774                 if (!NT_STATUS_IS_OK(status)) {
 775                         return status;
 776                 }
 777                 break;
 778
 779         default:
 780                 DEBUG(0, ("process_request_pdu: "
 781                           "unknown auth type %u set.\n",
 782                           (unsigned int)auth->auth_type));
 783                 return NT_STATUS_INVALID_PARAMETER;
 784         }
 785
 786         /* TODO: remove later
 787          * this is still needed because in the server code the
 788          * pkt_trailer actually has a copy of the raw data, and they
 789          * are still both used in later calls */
 790         if (auth->auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
 791                 memcpy(pkt_trailer->data, data.data, data.length);
 792         }
 793
 794         *pad_len = auth_info.auth_pad_length;
 795         data_blob_free(&auth_info.credentials);
 796         return NT_STATUS_OK;
 797 }
 798