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 "../libcli/auth/ntlmssp.h"
  28 #include "ntlmssp_wrap.h"
  29
  30 #undef DBGC_CLASS
  31 #define DBGC_CLASS DBGC_RPC_PARSE
  32
  33 /**
  34 * @brief NDR Encodes a ncacn_packet
  35 *
  36 * @param mem_ctx        The memory context the blob will be allocated on
  37 * @param ptype          The DCERPC packet type
  38 * @param pfc_flags      The DCERPC PFC Falgs
  39 * @param auth_length    The length of the trailing auth blob
  40 * @param call_id        The call ID
  41 * @param u              The payload of the packet
  42 * @param blob [out]     The encoded blob if successful
  43 *
  44 * @return an NTSTATUS error code
  45 */
  46 NTSTATUS dcerpc_push_ncacn_packet(TALLOC_CTX *mem_ctx,
  47                                   enum dcerpc_pkt_type ptype,
  48                                   uint8_t pfc_flags,
  49                                   uint16_t auth_length,
  50                                   uint32_t call_id,
  51                                   union dcerpc_payload *u,
  52                                   DATA_BLOB *blob)
  53 {
  54         struct ncacn_packet r;
  55         enum ndr_err_code ndr_err;
  56
  57         r.rpc_vers              = 5;
  58         r.rpc_vers_minor        = 0;
  59         r.ptype                 = ptype;
  60         r.pfc_flags             = pfc_flags;
  61         r.drep[0]               = DCERPC_DREP_LE;
  62         r.drep[1]               = 0;
  63         r.drep[2]               = 0;
  64         r.drep[3]               = 0;
  65         r.auth_length           = auth_length;
  66         r.call_id               = call_id;
  67         r.u                     = *u;
  68
  69         ndr_err = ndr_push_struct_blob(blob, mem_ctx, &r,
  70                 (ndr_push_flags_fn_t)ndr_push_ncacn_packet);
  71         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  72                 return ndr_map_error2ntstatus(ndr_err);
  73         }
  74
  75         dcerpc_set_frag_length(blob, blob->length);
  76
  77
  78         if (DEBUGLEVEL >= 10) {
  79                 /* set frag len for print function */
  80                 r.frag_length = blob->length;
  81                 NDR_PRINT_DEBUG(ncacn_packet, &r);
  82         }
  83
  84         return NT_STATUS_OK;
  85 }
  86
  87 /**
  88 * @brief Decodes a ncacn_packet
  89 *
  90 * @param mem_ctx        The memory context on which to allocate the packet
  91 *                       elements
  92 * @param blob           The blob of data to decode
  93 * @param r              An empty ncacn_packet, must not be NULL
  94 *
  95 * @return a NTSTATUS error code
  96 */
  97 NTSTATUS dcerpc_pull_ncacn_packet(TALLOC_CTX *mem_ctx,
  98                                   const DATA_BLOB *blob,
  99                                   struct ncacn_packet *r,
 100                                   bool bigendian)
 101 {
 102         enum ndr_err_code ndr_err;
 103         struct ndr_pull *ndr;
 104
 105         ndr = ndr_pull_init_blob(blob, mem_ctx);
 106         if (!ndr) {
 107                 return NT_STATUS_NO_MEMORY;
 108         }
 109         if (bigendian) {
 110                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
 111         }
 112
 113         ndr_err = ndr_pull_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, r);
 114
 115         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 116                 talloc_free(ndr);
 117                 return ndr_map_error2ntstatus(ndr_err);
 118         }
 119         talloc_free(ndr);
 120
 121         if (DEBUGLEVEL >= 10) {
 122                 NDR_PRINT_DEBUG(ncacn_packet, r);
 123         }
 124
 125         return NT_STATUS_OK;
 126 }
 127
 128 /**
 129 * @brief NDR Encodes a NL_AUTH_MESSAGE
 130 *
 131 * @param mem_ctx        The memory context the blob will be allocated on
 132 * @param r              The NL_AUTH_MESSAGE to encode
 133 * @param blob [out]     The encoded blob if successful
 134 *
 135 * @return a NTSTATUS error code
 136 */
 137 NTSTATUS dcerpc_push_schannel_bind(TALLOC_CTX *mem_ctx,
 138                                    struct NL_AUTH_MESSAGE *r,
 139                                    DATA_BLOB *blob)
 140 {
 141         enum ndr_err_code ndr_err;
 142
 143         ndr_err = ndr_push_struct_blob(blob, mem_ctx, r,
 144                 (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
 145         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 146                 return ndr_map_error2ntstatus(ndr_err);
 147         }
 148
 149         if (DEBUGLEVEL >= 10) {
 150                 NDR_PRINT_DEBUG(NL_AUTH_MESSAGE, r);
 151         }
 152
 153         return NT_STATUS_OK;
 154 }
 155
 156 /**
 157 * @brief NDR Encodes a dcerpc_auth structure
 158 *
 159 * @param mem_ctx          The memory context the blob will be allocated on
 160 * @param auth_type        The DCERPC Authentication Type
 161 * @param auth_level       The DCERPC Authentication Level
 162 * @param auth_pad_length  The padding added to the packet this blob will be
 163 *                          appended to.
 164 * @param auth_context_id  The context id
 165 * @param credentials      The authentication credentials blob (signature)
 166 * @param blob [out]       The encoded blob if successful
 167 *
 168 * @return a NTSTATUS error code
 169 */
 170 NTSTATUS dcerpc_push_dcerpc_auth(TALLOC_CTX *mem_ctx,
 171                                  enum dcerpc_AuthType auth_type,
 172                                  enum dcerpc_AuthLevel auth_level,
 173                                  uint8_t auth_pad_length,
 174                                  uint32_t auth_context_id,
 175                                  const DATA_BLOB *credentials,
 176                                  DATA_BLOB *blob)
 177 {
 178         struct dcerpc_auth r;
 179         enum ndr_err_code ndr_err;
 180
 181         r.auth_type             = auth_type;
 182         r.auth_level            = auth_level;
 183         r.auth_pad_length       = auth_pad_length;
 184         r.auth_reserved         = 0;
 185         r.auth_context_id       = auth_context_id;
 186         r.credentials           = *credentials;
 187
 188         ndr_err = ndr_push_struct_blob(blob, mem_ctx, &r,
 189                 (ndr_push_flags_fn_t)ndr_push_dcerpc_auth);
 190         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 191                 return ndr_map_error2ntstatus(ndr_err);
 192         }
 193
 194         if (DEBUGLEVEL >= 10) {
 195                 NDR_PRINT_DEBUG(dcerpc_auth, &r);
 196         }
 197
 198         return NT_STATUS_OK;
 199 }
 200
 201 /**
 202 * @brief Decodes a dcerpc_auth blob
 203 *
 204 * @param mem_ctx        The memory context on which to allocate the packet
 205 *                       elements
 206 * @param blob           The blob of data to decode
 207 * @param r              An empty dcerpc_auth structure, must not be NULL
 208 *
 209 * @return a NTSTATUS error code
 210 */
 211 NTSTATUS dcerpc_pull_dcerpc_auth(TALLOC_CTX *mem_ctx,
 212                                  const DATA_BLOB *blob,
 213                                  struct dcerpc_auth *r,
 214                                  bool bigendian)
 215 {
 216         enum ndr_err_code ndr_err;
 217         struct ndr_pull *ndr;
 218
 219         ndr = ndr_pull_init_blob(blob, mem_ctx);
 220         if (!ndr) {
 221                 return NT_STATUS_NO_MEMORY;
 222         }
 223         if (bigendian) {
 224                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
 225         }
 226
 227         ndr_err = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, r);
 228
 229         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 230                 talloc_free(ndr);
 231                 return ndr_map_error2ntstatus(ndr_err);
 232         }
 233         talloc_free(ndr);
 234
 235         if (DEBUGLEVEL >= 10) {
 236                 NDR_PRINT_DEBUG(dcerpc_auth, r);
 237         }
 238
 239         return NT_STATUS_OK;
 240 }
 241
 242 /*******************************************************************
 243  Create and add the NTLMSSP sign/seal auth data.
 244  ********************************************************************/
 245
 246 static NTSTATUS add_ntlmssp_auth_footer(struct auth_ntlmssp_state *auth_state,
 247                                         enum dcerpc_AuthLevel auth_level,
 248                                         DATA_BLOB *rpc_out)
 249 {
 250         uint16_t data_and_pad_len = rpc_out->length
 251                                         - DCERPC_RESPONSE_LENGTH
 252                                         - DCERPC_AUTH_TRAILER_LENGTH;
 253         DATA_BLOB auth_blob;
 254         NTSTATUS status;
 255
 256         if (!auth_state) {
 257                 return NT_STATUS_INVALID_PARAMETER;
 258         }
 259
 260         switch (auth_level) {
 261         case DCERPC_AUTH_LEVEL_PRIVACY:
 262                 /* Data portion is encrypted. */
 263                 status = auth_ntlmssp_seal_packet(auth_state,
 264                                              rpc_out->data,
 265                                              rpc_out->data
 266                                                 + DCERPC_RESPONSE_LENGTH,
 267                                              data_and_pad_len,
 268                                              rpc_out->data,
 269                                              rpc_out->length,
 270                                              &auth_blob);
 271                 if (!NT_STATUS_IS_OK(status)) {
 272                         return status;
 273                 }
 274                 break;
 275
 276         case DCERPC_AUTH_LEVEL_INTEGRITY:
 277                 /* Data is signed. */
 278                 status = auth_ntlmssp_sign_packet(auth_state,
 279                                              rpc_out->data,
 280                                              rpc_out->data
 281                                                 + DCERPC_RESPONSE_LENGTH,
 282                                              data_and_pad_len,
 283                                              rpc_out->data,
 284                                              rpc_out->length,
 285                                              &auth_blob);
 286                 if (!NT_STATUS_IS_OK(status)) {
 287                         return status;
 288                 }
 289                 break;
 290
 291         default:
 292                 /* Can't happen. */
 293                 smb_panic("bad auth level");
 294                 /* Notreached. */
 295                 return NT_STATUS_INVALID_PARAMETER;
 296         }
 297
 298         /* Finally attach the blob. */
 299         if (!data_blob_append(NULL, rpc_out,
 300                                 auth_blob.data, auth_blob.length)) {
 301                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 302                           (unsigned int)auth_blob.length));
 303                 return NT_STATUS_NO_MEMORY;
 304         }
 305         data_blob_free(&auth_blob);
 306
 307         return NT_STATUS_OK;
 308 }
 309
 310 /*******************************************************************
 311  Create and add the schannel sign/seal auth data.
 312  ********************************************************************/
 313
 314 static NTSTATUS add_schannel_auth_footer(struct schannel_state *sas,
 315                                         enum dcerpc_AuthLevel auth_level,
 316                                         DATA_BLOB *rpc_out)
 317 {
 318         uint8_t *data_p = rpc_out->data + DCERPC_RESPONSE_LENGTH;
 319         size_t data_and_pad_len = rpc_out->length
 320                                         - DCERPC_RESPONSE_LENGTH
 321                                         - DCERPC_AUTH_TRAILER_LENGTH;
 322         DATA_BLOB auth_blob;
 323         NTSTATUS status;
 324
 325         if (!sas) {
 326                 return NT_STATUS_INVALID_PARAMETER;
 327         }
 328
 329         DEBUG(10,("add_schannel_auth_footer: SCHANNEL seq_num=%d\n",
 330                         sas->seq_num));
 331
 332         switch (auth_level) {
 333         case DCERPC_AUTH_LEVEL_PRIVACY:
 334                 status = netsec_outgoing_packet(sas,
 335                                                 rpc_out->data,
 336                                                 true,
 337                                                 data_p,
 338                                                 data_and_pad_len,
 339                                                 &auth_blob);
 340                 break;
 341         case DCERPC_AUTH_LEVEL_INTEGRITY:
 342                 status = netsec_outgoing_packet(sas,
 343                                                 rpc_out->data,
 344                                                 false,
 345                                                 data_p,
 346                                                 data_and_pad_len,
 347                                                 &auth_blob);
 348                 break;
 349         default:
 350                 status = NT_STATUS_INTERNAL_ERROR;
 351                 break;
 352         }
 353
 354         if (!NT_STATUS_IS_OK(status)) {
 355                 DEBUG(1,("add_schannel_auth_footer: failed to process packet: %s\n",
 356                         nt_errstr(status)));
 357                 return status;
 358         }
 359
 360         if (DEBUGLEVEL >= 10) {
 361                 dump_NL_AUTH_SIGNATURE(talloc_tos(), &auth_blob);
 362         }
 363
 364         /* Finally attach the blob. */
 365         if (!data_blob_append(NULL, rpc_out,
 366                                 auth_blob.data, auth_blob.length)) {
 367                 return NT_STATUS_NO_MEMORY;
 368         }
 369         data_blob_free(&auth_blob);
 370
 371         return NT_STATUS_OK;
 372 }
 373
 374 /**
 375 * @brief   Append an auth footer according to what is the current mechanism
 376 *
 377 * @param auth           The pipe_auth_data associated with the connection
 378 * @param pad_len        The padding used in the packet
 379 * @param rpc_out        Packet blob up to and including the auth header
 380 *
 381 * @return A NTSTATUS error code.
 382 */
 383 NTSTATUS dcerpc_add_auth_footer(struct pipe_auth_data *auth,
 384                                 size_t pad_len, DATA_BLOB *rpc_out)
 385 {
 386         enum dcerpc_AuthType auth_type;
 387         char pad[CLIENT_NDR_PADDING_SIZE] = { 0, };
 388         DATA_BLOB auth_info;
 389         DATA_BLOB auth_blob;
 390         NTSTATUS status;
 391
 392         if (auth->auth_type == PIPE_AUTH_TYPE_NONE) {
 393                 return NT_STATUS_OK;
 394         }
 395
 396         if (pad_len) {
 397                 /* Copy the sign/seal padding data. */
 398                 if (!data_blob_append(NULL, rpc_out, pad, pad_len)) {
 399                         return NT_STATUS_NO_MEMORY;
 400                 }
 401         }
 402
 403         auth_type = map_pipe_auth_type_to_rpc_auth_type(auth->auth_type);
 404
 405         /* marshall the dcerpc_auth with an actually empty auth_blob.
 406          * This is needed because the ntmlssp signature includes the
 407          * auth header. We will append the actual blob later. */
 408         auth_blob = data_blob_null;
 409         status = dcerpc_push_dcerpc_auth(rpc_out->data,
 410                                          auth_type,
 411                                          auth->auth_level,
 412                                          pad_len,
 413                                          1 /* context id. */,
 414                                          &auth_blob,
 415                                          &auth_info);
 416         if (!NT_STATUS_IS_OK(status)) {
 417                 return status;
 418         }
 419
 420         /* append the header */
 421         if (!data_blob_append(NULL, rpc_out,
 422                                 auth_info.data, auth_info.length)) {
 423                 DEBUG(0, ("Failed to add %u bytes auth blob.\n",
 424                           (unsigned int)auth_info.length));
 425                 return NT_STATUS_NO_MEMORY;
 426         }
 427         data_blob_free(&auth_info);
 428
 429         /* Generate any auth sign/seal and add the auth footer. */
 430         switch (auth->auth_type) {
 431         case PIPE_AUTH_TYPE_NONE:
 432                 status = NT_STATUS_OK;
 433                 break;
 434         case PIPE_AUTH_TYPE_NTLMSSP:
 435         case PIPE_AUTH_TYPE_SPNEGO_NTLMSSP:
 436                 status = add_ntlmssp_auth_footer(auth->a_u.auth_ntlmssp_state,
 437                                                  auth->auth_level,
 438                                                  rpc_out);
 439                 break;
 440         case PIPE_AUTH_TYPE_SCHANNEL:
 441                 status = add_schannel_auth_footer(auth->a_u.schannel_auth,
 442                                                   auth->auth_level,
 443                                                   rpc_out);
 444                 break;
 445         default:
 446                 status = NT_STATUS_INVALID_PARAMETER;
 447                 break;
 448         }
 449
 450         return status;
 451 }
 452