5169031d1634781c4692015bb2f5e40369fc7b8a
[samba.git] / 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 3 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, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "rpc_server/dcerpc_server.h"
25 #include "rpc_server/dcerpc_server_proto.h"
26 #include "librpc/rpc/dcerpc_proto.h"
27 #include "librpc/gen_ndr/ndr_dcerpc.h"
28 #include "auth/credentials/credentials.h"
29 #include "auth/gensec/gensec.h"
30 #include "param/param.h"
31
32 /*
33   parse any auth information from a dcerpc bind request
34   return false if we can't handle the auth request for some 
35   reason (in which case we send a bind_nak)
36 */
37 bool dcesrv_auth_bind(struct dcesrv_call_state *call)
38 {
39         struct cli_credentials *server_credentials;
40         struct ncacn_packet *pkt = &call->pkt;
41         struct dcesrv_connection *dce_conn = call->conn;
42         struct dcesrv_auth *auth = &dce_conn->auth_state;
43         NTSTATUS status;
44         enum ndr_err_code ndr_err;
45
46         if (pkt->u.bind.auth_info.length == 0) {
47                 dce_conn->auth_state.auth_info = NULL;
48                 return true;
49         }
50
51         dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth);
52         if (!dce_conn->auth_state.auth_info) {
53                 return false;
54         }
55
56         ndr_err = ndr_pull_struct_blob(&pkt->u.bind.auth_info,
57                                        call, NULL,
58                                        dce_conn->auth_state.auth_info,
59                                        (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
60         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
61                 return false;
62         }
63
64         status = gensec_server_start(dce_conn, call->event_ctx, 
65                                      lp_gensec_settings(dce_conn, call->conn->dce_ctx->lp_ctx), 
66                                      call->msg_ctx, &auth->gensec_security);
67         if (!NT_STATUS_IS_OK(status)) {
68                 DEBUG(1, ("Failed to start GENSEC for DCERPC server: %s\n", nt_errstr(status)));
69                 return false;
70         }
71
72         server_credentials 
73                 = cli_credentials_init(call);
74         if (!server_credentials) {
75                 DEBUG(1, ("Failed to init server credentials\n"));
76                 return false;
77         }
78         
79         cli_credentials_set_conf(server_credentials, call->conn->dce_ctx->lp_ctx);
80         status = cli_credentials_set_machine_account(server_credentials, call->conn->dce_ctx->lp_ctx);
81         if (!NT_STATUS_IS_OK(status)) {
82                 DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
83                 talloc_free(server_credentials);
84                 server_credentials = NULL;
85         }
86
87         gensec_set_credentials(auth->gensec_security, server_credentials);
88
89         status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_info->auth_type, 
90                                                auth->auth_info->auth_level);
91
92         if (!NT_STATUS_IS_OK(status)) {
93                 DEBUG(1, ("Failed to start GENSEC mechanism for DCERPC server: auth_type=%d, auth_level=%d: %s\n", 
94                           (int)auth->auth_info->auth_type,
95                           (int)auth->auth_info->auth_level,
96                           nt_errstr(status)));
97                 return false;
98         }
99
100         if (call->conn->state_flags & DCESRV_CALL_STATE_FLAG_HEADER_SIGNING) {
101                 gensec_want_feature(auth->gensec_security, GENSEC_FEATURE_SIGN_PKT_HEADER);
102         }
103
104         return true;
105 }
106
107 /*
108   add any auth information needed in a bind ack, and process the authentication
109   information found in the bind.
110 */
111 NTSTATUS dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
112 {
113         struct dcesrv_connection *dce_conn = call->conn;
114         NTSTATUS status;
115
116         if (!call->conn->auth_state.gensec_security) {
117                 return NT_STATUS_OK;
118         }
119
120         status = gensec_update(dce_conn->auth_state.gensec_security,
121                                call,
122                                dce_conn->auth_state.auth_info->credentials, 
123                                &dce_conn->auth_state.auth_info->credentials);
124         
125         if (NT_STATUS_IS_OK(status)) {
126                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
127                                              &dce_conn->auth_state.session_info);
128                 if (!NT_STATUS_IS_OK(status)) {
129                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
130                         return status;
131                 }
132
133                 if (dce_conn->state_flags & DCESRV_CALL_STATE_FLAG_HEADER_SIGNING) {
134                         gensec_want_feature(dce_conn->auth_state.gensec_security,
135                                             GENSEC_FEATURE_SIGN_PKT_HEADER);
136                 }
137
138                 /* Now that we are authenticated, go back to the generic session key... */
139                 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
140                 return NT_STATUS_OK;
141         } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
142                 dce_conn->auth_state.auth_info->auth_pad_length = 0;
143                 dce_conn->auth_state.auth_info->auth_reserved = 0;
144                 return NT_STATUS_OK;
145         } else {
146                 DEBUG(2, ("Failed to start dcesrv auth negotiate: %s\n", nt_errstr(status)));
147                 return status;
148         }
149 }
150
151
152 /*
153   process the final stage of a auth request
154 */
155 bool dcesrv_auth_auth3(struct dcesrv_call_state *call)
156 {
157         struct ncacn_packet *pkt = &call->pkt;
158         struct dcesrv_connection *dce_conn = call->conn;
159         NTSTATUS status;
160         enum ndr_err_code ndr_err;
161
162         /* We can't work without an existing gensec state, and an new blob to feed it */
163         if (!dce_conn->auth_state.auth_info ||
164             !dce_conn->auth_state.gensec_security ||
165             pkt->u.auth3.auth_info.length == 0) {
166                 return false;
167         }
168
169         ndr_err = ndr_pull_struct_blob(&pkt->u.auth3.auth_info,
170                                        call, NULL,
171                                        dce_conn->auth_state.auth_info,
172                                        (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
173         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
174                 return false;
175         }
176
177         /* Pass the extra data we got from the client down to gensec for processing */
178         status = gensec_update(dce_conn->auth_state.gensec_security,
179                                call,
180                                dce_conn->auth_state.auth_info->credentials, 
181                                &dce_conn->auth_state.auth_info->credentials);
182         if (NT_STATUS_IS_OK(status)) {
183                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
184                                              &dce_conn->auth_state.session_info);
185                 if (!NT_STATUS_IS_OK(status)) {
186                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
187                         return false;
188                 }
189                 /* Now that we are authenticated, go back to the generic session key... */
190                 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
191                 return true;
192         } else {
193                 DEBUG(4, ("dcesrv_auth_auth3: failed to authenticate: %s\n", 
194                           nt_errstr(status)));
195                 return false;
196         }
197
198         return true;
199 }
200
201 /*
202   parse any auth information from a dcerpc alter request
203   return false if we can't handle the auth request for some 
204   reason (in which case we send a bind_nak (is this true for here?))
205 */
206 bool dcesrv_auth_alter(struct dcesrv_call_state *call)
207 {
208         struct ncacn_packet *pkt = &call->pkt;
209         struct dcesrv_connection *dce_conn = call->conn;
210         enum ndr_err_code ndr_err;
211
212         /* on a pure interface change there is no auth blob */
213         if (pkt->u.alter.auth_info.length == 0) {
214                 return true;
215         }
216
217         /* We can't work without an existing gensec state */
218         if (!dce_conn->auth_state.gensec_security) {
219                 return false;
220         }
221
222         dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth);
223         if (!dce_conn->auth_state.auth_info) {
224                 return false;
225         }
226
227         ndr_err = ndr_pull_struct_blob(&pkt->u.alter.auth_info,
228                                        call, NULL,
229                                        dce_conn->auth_state.auth_info,
230                                        (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
231         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
232                 return false;
233         }
234
235         return true;
236 }
237
238 /*
239   add any auth information needed in a alter ack, and process the authentication
240   information found in the alter.
241 */
242 NTSTATUS dcesrv_auth_alter_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
243 {
244         struct dcesrv_connection *dce_conn = call->conn;
245         NTSTATUS status;
246
247         /* on a pure interface change there is no auth_info structure
248            setup */
249         if (!call->conn->auth_state.auth_info ||
250             dce_conn->auth_state.auth_info->credentials.length == 0) {
251                 return NT_STATUS_OK;
252         }
253
254         if (!call->conn->auth_state.gensec_security) {
255                 return NT_STATUS_INVALID_PARAMETER;
256         }
257
258         status = gensec_update(dce_conn->auth_state.gensec_security,
259                                call,
260                                dce_conn->auth_state.auth_info->credentials, 
261                                &dce_conn->auth_state.auth_info->credentials);
262
263         if (NT_STATUS_IS_OK(status)) {
264                 status = gensec_session_info(dce_conn->auth_state.gensec_security,
265                                              &dce_conn->auth_state.session_info);
266                 if (!NT_STATUS_IS_OK(status)) {
267                         DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
268                         return status;
269                 }
270
271                 /* Now that we are authenticated, got back to the generic session key... */
272                 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
273                 return NT_STATUS_OK;
274         } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
275                 dce_conn->auth_state.auth_info->auth_pad_length = 0;
276                 dce_conn->auth_state.auth_info->auth_reserved = 0;
277                 return NT_STATUS_OK;
278         }
279
280         DEBUG(2, ("Failed to finish dcesrv auth alter_ack: %s\n", nt_errstr(status)));
281         return status;
282 }
283
284 /*
285   check credentials on a request
286 */
287 bool dcesrv_auth_request(struct dcesrv_call_state *call, DATA_BLOB *full_packet)
288 {
289         struct ncacn_packet *pkt = &call->pkt;
290         struct dcesrv_connection *dce_conn = call->conn;
291         DATA_BLOB auth_blob;
292         struct dcerpc_auth auth;
293         struct ndr_pull *ndr;
294         NTSTATUS status;
295         enum ndr_err_code ndr_err;
296         size_t hdr_size = DCERPC_REQUEST_LENGTH;
297
298         if (!dce_conn->auth_state.auth_info ||
299             !dce_conn->auth_state.gensec_security) {
300                 return true;
301         }
302
303         switch (dce_conn->auth_state.auth_info->auth_level) {
304         case DCERPC_AUTH_LEVEL_PRIVACY:
305         case DCERPC_AUTH_LEVEL_INTEGRITY:
306                 break;
307
308         case DCERPC_AUTH_LEVEL_CONNECT:
309                 if (pkt->auth_length != 0) {
310                         break;
311                 }
312                 return true;
313         case DCERPC_AUTH_LEVEL_NONE:
314                 if (pkt->auth_length != 0) {
315                         return false;
316                 }
317                 return true;
318
319         default:
320                 return false;
321         }
322
323         auth_blob.length = 8 + pkt->auth_length;
324
325         /* check for a valid length */
326         if (pkt->u.request.stub_and_verifier.length < auth_blob.length) {
327                 return false;
328         }
329
330         auth_blob.data = 
331                 pkt->u.request.stub_and_verifier.data + 
332                 pkt->u.request.stub_and_verifier.length - auth_blob.length;
333         pkt->u.request.stub_and_verifier.length -= auth_blob.length;
334
335         /* pull the auth structure */
336         ndr = ndr_pull_init_blob(&auth_blob, call, lp_iconv_convenience(call->conn->dce_ctx->lp_ctx));
337         if (!ndr) {
338                 return false;
339         }
340
341         if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
342                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
343         }
344
345         if (pkt->pfc_flags & DCERPC_PFC_FLAG_OBJECT_UUID) {
346                 ndr->flags |= LIBNDR_FLAG_OBJECT_PRESENT;
347                 hdr_size += 16;
348         }
349
350         ndr_err = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, &auth);
351         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
352                 talloc_free(ndr);
353                 return false;
354         }
355
356         /* check signature or unseal the packet */
357         switch (dce_conn->auth_state.auth_info->auth_level) {
358         case DCERPC_AUTH_LEVEL_PRIVACY:
359                 status = gensec_unseal_packet(dce_conn->auth_state.gensec_security,
360                                               call,
361                                               full_packet->data + hdr_size,
362                                               pkt->u.request.stub_and_verifier.length, 
363                                               full_packet->data,
364                                               full_packet->length-auth.credentials.length,
365                                               &auth.credentials);
366                 memcpy(pkt->u.request.stub_and_verifier.data, 
367                        full_packet->data + hdr_size,
368                        pkt->u.request.stub_and_verifier.length);
369                 break;
370
371         case DCERPC_AUTH_LEVEL_INTEGRITY:
372                 status = gensec_check_packet(dce_conn->auth_state.gensec_security,
373                                              call,
374                                              pkt->u.request.stub_and_verifier.data, 
375                                              pkt->u.request.stub_and_verifier.length,
376                                              full_packet->data,
377                                              full_packet->length-auth.credentials.length,
378                                              &auth.credentials);
379                 break;
380
381         case DCERPC_AUTH_LEVEL_CONNECT:
382                 /* for now we ignore possible signatures here */
383                 status = NT_STATUS_OK;
384                 break;
385
386         default:
387                 status = NT_STATUS_INVALID_LEVEL;
388                 break;
389         }
390
391         /* remove the indicated amount of padding */
392         if (pkt->u.request.stub_and_verifier.length < auth.auth_pad_length) {
393                 talloc_free(ndr);
394                 return false;
395         }
396         pkt->u.request.stub_and_verifier.length -= auth.auth_pad_length;
397         talloc_free(ndr);
398
399         return NT_STATUS_IS_OK(status);
400 }
401
402
403 /* 
404    push a signed or sealed dcerpc request packet into a blob
405 */
406 bool dcesrv_auth_response(struct dcesrv_call_state *call,
407                           DATA_BLOB *blob, size_t sig_size,
408                           struct ncacn_packet *pkt)
409 {
410         struct dcesrv_connection *dce_conn = call->conn;
411         NTSTATUS status;
412         enum ndr_err_code ndr_err;
413         struct ndr_push *ndr;
414         uint32_t payload_length;
415         DATA_BLOB creds2;
416
417         /* non-signed packets are simple */
418         if (sig_size == 0) {
419                 status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL);
420                 return NT_STATUS_IS_OK(status);
421         }
422
423         switch (dce_conn->auth_state.auth_info->auth_level) {
424         case DCERPC_AUTH_LEVEL_PRIVACY:
425         case DCERPC_AUTH_LEVEL_INTEGRITY:
426                 break;
427
428         case DCERPC_AUTH_LEVEL_CONNECT:
429                 /*
430                  * TODO: let the gensec mech decide if it wants to generate a signature
431                  *       that might be needed for schannel...
432                  */
433                 status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL);
434                 return NT_STATUS_IS_OK(status);
435
436         case DCERPC_AUTH_LEVEL_NONE:
437                 status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL);
438                 return NT_STATUS_IS_OK(status);
439
440         default:
441                 return false;
442         }
443
444         ndr = ndr_push_init_ctx(call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx));
445         if (!ndr) {
446                 return false;
447         }
448
449         if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
450                 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
451         }
452
453         ndr_err = ndr_push_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
454         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
455                 return false;
456         }
457
458         /* pad to 16 byte multiple, match win2k3 */
459         dce_conn->auth_state.auth_info->auth_pad_length =
460                 (16 - (pkt->u.response.stub_and_verifier.length & 15)) & 15;
461         ndr_err = ndr_push_zero(ndr, dce_conn->auth_state.auth_info->auth_pad_length);
462         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
463                 return false;
464         }
465
466         payload_length = pkt->u.response.stub_and_verifier.length +
467                 dce_conn->auth_state.auth_info->auth_pad_length;
468
469         /* we start without signature, it will appended later */
470         dce_conn->auth_state.auth_info->credentials = data_blob(NULL, 0);
471
472         /* add the auth verifier */
473         ndr_err = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS,
474                                       dce_conn->auth_state.auth_info);
475         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
476                 return false;
477         }
478
479         /* extract the whole packet as a blob */
480         *blob = ndr_push_blob(ndr);
481
482         /*
483          * Setup the frag and auth length in the packet buffer.
484          * This is needed if the GENSEC mech does AEAD signing
485          * of the packet headers. The signature itself will be
486          * appended later.
487          */
488         dcerpc_set_frag_length(blob, blob->length + sig_size);
489         dcerpc_set_auth_length(blob, sig_size);
490
491         /* sign or seal the packet */
492         switch (dce_conn->auth_state.auth_info->auth_level) {
493         case DCERPC_AUTH_LEVEL_PRIVACY:
494                 status = gensec_seal_packet(dce_conn->auth_state.gensec_security, 
495                                             call,
496                                             ndr->data + DCERPC_REQUEST_LENGTH, 
497                                             payload_length,
498                                             blob->data,
499                                             blob->length,
500                                             &creds2);
501                 break;
502
503         case DCERPC_AUTH_LEVEL_INTEGRITY:
504                 status = gensec_sign_packet(dce_conn->auth_state.gensec_security, 
505                                             call,
506                                             ndr->data + DCERPC_REQUEST_LENGTH, 
507                                             payload_length,
508                                             blob->data,
509                                             blob->length,
510                                             &creds2);
511                 break;
512
513         default:
514                 status = NT_STATUS_INVALID_LEVEL;
515                 break;
516         }
517
518         if (NT_STATUS_IS_OK(status)) {
519                 if (creds2.length != sig_size) {
520                         DEBUG(0,("dcesrv_auth_response: creds2.length[%u] != sig_size[%u] pad[%u] stub[%u]\n",
521                                 creds2.length, (uint32_t)sig_size,
522                                 dce_conn->auth_state.auth_info->auth_pad_length,
523                                 pkt->u.response.stub_and_verifier.length));
524                         data_blob_free(&creds2);
525                         status = NT_STATUS_INTERNAL_ERROR;
526                 }
527         }
528
529         if (NT_STATUS_IS_OK(status)) {
530                 if (!data_blob_append(call, blob, creds2.data, creds2.length)) {
531                         status = NT_STATUS_NO_MEMORY;
532                 }
533                 data_blob_free(&creds2);
534         }
535
536         if (!NT_STATUS_IS_OK(status)) {
537                 return false;
538         }       
539
540         return true;
541 }