source4/rpc_server/dcesrv_auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    server side dcerpc authentication code
   5
   6    Copyright (C) Andrew Tridgell 2003
   7    Copyright (C) Stefan (metze) Metzmacher 2004
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25
  26 /*
  27   startup the cryptographic side of an authenticated dcerpc server
  28 */
  29 NTSTATUS dcesrv_crypto_select_type(struct dcesrv_connection *dce_conn,
  30                                struct dcesrv_auth *auth)
  31 {
  32         NTSTATUS status;
  33         if (auth->auth_info->auth_level != DCERPC_AUTH_LEVEL_INTEGRITY &&
  34             auth->auth_info->auth_level != DCERPC_AUTH_LEVEL_PRIVACY) {
  35                 DEBUG(2,("auth_level %d not supported in dcesrv auth\n",
  36                          auth->auth_info->auth_level));
  37                 return NT_STATUS_INVALID_PARAMETER;
  38         }
  39
  40         if (auth->gensec_security != NULL) {
  41                 /* TODO:
  42                  * this this function should not be called
  43                  * twice per dcesrv_connection!
  44                  *
  45                  * so we need to find out the right
  46                  * dcerpc error to return
  47                  */
  48         }
  49
  50         status = gensec_server_start(&auth->gensec_security);
  51         if (!NT_STATUS_IS_OK(status)) {
  52                 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
  53                 return status;
  54         }
  55
  56         status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_info->auth_type);
  57
  58         if (!NT_STATUS_IS_OK(status)) {
  59                 DEBUG(1, ("Failed to start GENSEC mech-specific server code (%d): %s\n",
  60                           (int)auth->auth_info->auth_type,
  61                           nt_errstr(status)));
  62                 return status;
  63         }
  64
  65         return status;
  66 }
  67
  68 /*
  69   parse any auth information from a dcerpc bind request
  70   return False if we can't handle the auth request for some
  71   reason (in which case we send a bind_nak)
  72 */
  73 BOOL dcesrv_auth_bind(struct dcesrv_call_state *call)
  74 {
  75         struct dcerpc_packet *pkt = &call->pkt;
  76         struct dcesrv_connection *dce_conn = call->conn;
  77         NTSTATUS status;
  78
  79         if (pkt->u.bind.auth_info.length == 0) {
  80                 dce_conn->auth_state.auth_info = NULL;
  81                 return True;
  82         }
  83
  84         dce_conn->auth_state.auth_info = talloc_p(dce_conn->mem_ctx, struct dcerpc_auth);
  85         if (!dce_conn->auth_state.auth_info) {
  86                 return False;
  87         }
  88
  89         status = ndr_pull_struct_blob(&pkt->u.bind.auth_info,
  90                                       call->mem_ctx,
  91                                       dce_conn->auth_state.auth_info,
  92                                       (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
  93         if (!NT_STATUS_IS_OK(status)) {
  94                 return False;
  95         }
  96
  97         status = dcesrv_crypto_select_type(dce_conn, &dce_conn->auth_state);
  98         if (!NT_STATUS_IS_OK(status)) {
  99                 return False;
 100         }
 101
 102         return True;
 103 }
 104
 105 /*
 106   add any auth information needed in a bind ack, and process the authentication
 107   information found in the bind.
 108 */
 109 BOOL dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct dcerpc_packet *pkt)
 110 {
 111         struct dcesrv_connection *dce_conn = call->conn;
 112         NTSTATUS status;
 113
 114         if (!call->conn->auth_state.gensec_security) {
 115                 return True;
 116         }
 117
 118         status = gensec_update(dce_conn->auth_state.gensec_security,
 119                                call->mem_ctx,
 120                                dce_conn->auth_state.auth_info->credentials,
 121                                &dce_conn->auth_state.auth_info->credentials);
 122
 123         if (NT_STATUS_IS_OK(status)) {
 124                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
 125                                              &dce_conn->auth_state.session_info);
 126                 if (!NT_STATUS_IS_OK(status)) {
 127                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
 128                         return False;
 129                 }
 130                 return True;
 131         } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 132                 dce_conn->auth_state.auth_info->auth_pad_length = 0;
 133                 dce_conn->auth_state.auth_info->auth_reserved = 0;
 134                 return True;
 135         } else {
 136                 DEBUG(2, ("Failed to start dcesrv auth negotiate: %s\n", nt_errstr(status)));
 137                 return False;
 138         }
 139 }
 140
 141
 142 /*
 143   process the final stage of a auth request
 144 */
 145 BOOL dcesrv_auth_auth3(struct dcesrv_call_state *call)
 146 {
 147         struct dcerpc_packet *pkt = &call->pkt;
 148         struct dcesrv_connection *dce_conn = call->conn;
 149         NTSTATUS status;
 150
 151         if (!dce_conn->auth_state.auth_info ||
 152             !dce_conn->auth_state.gensec_security ||
 153             pkt->u.auth.auth_info.length == 0) {
 154                 return False;
 155         }
 156
 157         status = ndr_pull_struct_blob(&pkt->u.auth.auth_info,
 158                                       call->mem_ctx,
 159                                       dce_conn->auth_state.auth_info,
 160                                       (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
 161         if (!NT_STATUS_IS_OK(status)) {
 162                 return False;
 163         }
 164
 165         status = gensec_update(dce_conn->auth_state.gensec_security,
 166                                call->mem_ctx,
 167                                dce_conn->auth_state.auth_info->credentials,
 168                                &dce_conn->auth_state.auth_info->credentials);
 169         if (NT_STATUS_IS_OK(status)) {
 170                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
 171                                              &dce_conn->auth_state.session_info);
 172                 if (!NT_STATUS_IS_OK(status)) {
 173                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
 174                         return False;
 175                 }
 176                 return True;
 177         } else {
 178                 DEBUG(4, ("dcesrv_auth_auth3: failed to authenticate: %s\n",
 179                           nt_errstr(status)));
 180                 return False;
 181         }
 182
 183         return True;
 184 }
 185
 186
 187 /*
 188   check credentials on a request
 189 */
 190 BOOL dcesrv_auth_request(struct dcesrv_call_state *call)
 191 {
 192         struct dcerpc_packet *pkt = &call->pkt;
 193         struct dcesrv_connection *dce_conn = call->conn;
 194         DATA_BLOB auth_blob;
 195         struct dcerpc_auth auth;
 196         struct ndr_pull *ndr;
 197         NTSTATUS status;
 198
 199         if (!dce_conn->auth_state.auth_info ||
 200             !dce_conn->auth_state.gensec_security) {
 201                 return True;
 202         }
 203
 204         auth_blob.length = 8 + pkt->auth_length;
 205
 206         /* check for a valid length */
 207         if (pkt->u.request.stub_and_verifier.length < auth_blob.length) {
 208                 return False;
 209         }
 210
 211         auth_blob.data =
 212                 pkt->u.request.stub_and_verifier.data +
 213                 pkt->u.request.stub_and_verifier.length - auth_blob.length;
 214         pkt->u.request.stub_and_verifier.length -= auth_blob.length;
 215
 216         /* pull the auth structure */
 217         ndr = ndr_pull_init_blob(&auth_blob, call->mem_ctx);
 218         if (!ndr) {
 219                 return False;
 220         }
 221
 222         if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
 223                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
 224         }
 225
 226         status = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, &auth);
 227         if (!NT_STATUS_IS_OK(status)) {
 228                 return False;
 229         }
 230
 231         /* check signature or unseal the packet */
 232         switch (dce_conn->auth_state.auth_info->auth_level) {
 233         case DCERPC_AUTH_LEVEL_PRIVACY:
 234                 status = gensec_unseal_packet(dce_conn->auth_state.gensec_security,
 235                                               call->mem_ctx,
 236                                               pkt->u.request.stub_and_verifier.data,
 237                                               pkt->u.request.stub_and_verifier.length,
 238                                               &auth.credentials);
 239                 break;
 240
 241         case DCERPC_AUTH_LEVEL_INTEGRITY:
 242                 status = gensec_check_packet(dce_conn->auth_state.gensec_security,
 243                                              call->mem_ctx,
 244                                              pkt->u.request.stub_and_verifier.data,
 245                                              pkt->u.request.stub_and_verifier.length,
 246                                              &auth.credentials);
 247                 break;
 248
 249         default:
 250                 status = NT_STATUS_INVALID_LEVEL;
 251                 break;
 252         }
 253
 254         /* remove the indicated amount of paddiing */
 255         if (pkt->u.request.stub_and_verifier.length < auth.auth_pad_length) {
 256                 return False;
 257         }
 258         pkt->u.request.stub_and_verifier.length -= auth.auth_pad_length;
 259
 260         return NT_STATUS_IS_OK(status);
 261 }
 262
 263
 264 /*
 265    push a signed or sealed dcerpc request packet into a blob
 266 */
 267 BOOL dcesrv_auth_response(struct dcesrv_call_state *call,
 268                           DATA_BLOB *blob, struct dcerpc_packet *pkt)
 269 {
 270         struct dcesrv_connection *dce_conn = call->conn;
 271         NTSTATUS status;
 272         struct ndr_push *ndr;
 273
 274         /* non-signed packets are simple */
 275         if (!dce_conn->auth_state.auth_info || !dce_conn->auth_state.gensec_security) {
 276                 status = dcerpc_push_auth(blob, call->mem_ctx, pkt, NULL);
 277                 return NT_STATUS_IS_OK(status);
 278         }
 279
 280         ndr = ndr_push_init_ctx(call->mem_ctx);
 281         if (!ndr) {
 282                 return False;
 283         }
 284
 285         if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
 286                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
 287         }
 288
 289         status = ndr_push_dcerpc_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
 290         if (!NT_STATUS_IS_OK(status)) {
 291                 return False;
 292         }
 293
 294         /* pad to 8 byte multiple */
 295         dce_conn->auth_state.auth_info->auth_pad_length = NDR_ALIGN(ndr, 8);
 296         ndr_push_zero(ndr, dce_conn->auth_state.auth_info->auth_pad_length);
 297
 298         /* sign or seal the packet */
 299         switch (dce_conn->auth_state.auth_info->auth_level) {
 300         case DCERPC_AUTH_LEVEL_PRIVACY:
 301                 status = gensec_seal_packet(dce_conn->auth_state.gensec_security,
 302                                               call->mem_ctx,
 303                                               ndr->data + DCERPC_REQUEST_LENGTH,
 304                                               ndr->offset - DCERPC_REQUEST_LENGTH,
 305                                               &dce_conn->auth_state.auth_info->credentials);
 306                 break;
 307
 308         case DCERPC_AUTH_LEVEL_INTEGRITY:
 309                 status = gensec_sign_packet(dce_conn->auth_state.gensec_security,
 310                                             call->mem_ctx,
 311                                             ndr->data + DCERPC_REQUEST_LENGTH,
 312                                             ndr->offset - DCERPC_REQUEST_LENGTH,
 313                                             &dce_conn->auth_state.auth_info->credentials);
 314                 break;
 315         default:
 316                 status = NT_STATUS_INVALID_LEVEL;
 317                 break;
 318         }
 319
 320         if (!NT_STATUS_IS_OK(status)) {
 321                 return False;
 322         }
 323
 324         /* add the auth verifier */
 325         status = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, dce_conn->auth_state.auth_info);
 326         if (!NT_STATUS_IS_OK(status)) {
 327                 return False;
 328         }
 329
 330         /* extract the whole packet as a blob */
 331         *blob = ndr_push_blob(ndr);
 332
 333         /* fill in the fragment length and auth_length, we can't fill
 334            in these earlier as we don't know the signature length (it
 335            could be variable length) */
 336         dcerpc_set_frag_length(blob, blob->length);
 337         dcerpc_set_auth_length(blob, dce_conn->auth_state.auth_info->credentials.length);
 338
 339         data_blob_free(&dce_conn->auth_state.auth_info->credentials);
 340
 341         return True;
 342 }