source: branches/samba-3.5.x/source4/rpc_server/dcesrv_auth.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 15.6 KB
Line 
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 "auth/auth.h"
31#include "param/param.h"
32
33/*
34 parse any auth information from a dcerpc bind request
35 return false if we can't handle the auth request for some
36 reason (in which case we send a bind_nak)
37*/
38bool dcesrv_auth_bind(struct dcesrv_call_state *call)
39{
40 struct cli_credentials *server_credentials;
41 struct ncacn_packet *pkt = &call->pkt;
42 struct dcesrv_connection *dce_conn = call->conn;
43 struct dcesrv_auth *auth = &dce_conn->auth_state;
44 NTSTATUS status;
45 enum ndr_err_code ndr_err;
46
47 if (pkt->u.bind.auth_info.length == 0) {
48 dce_conn->auth_state.auth_info = NULL;
49 return true;
50 }
51
52 dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth);
53 if (!dce_conn->auth_state.auth_info) {
54 return false;
55 }
56
57 ndr_err = ndr_pull_struct_blob(&pkt->u.bind.auth_info,
58 call, NULL,
59 dce_conn->auth_state.auth_info,
60 (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
61 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
62 return false;
63 }
64
65 server_credentials
66 = cli_credentials_init(call);
67 if (!server_credentials) {
68 DEBUG(1, ("Failed to init server credentials\n"));
69 return false;
70 }
71
72 cli_credentials_set_conf(server_credentials, call->conn->dce_ctx->lp_ctx);
73 status = cli_credentials_set_machine_account(server_credentials, call->conn->dce_ctx->lp_ctx);
74 if (!NT_STATUS_IS_OK(status)) {
75 DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
76 talloc_free(server_credentials);
77 server_credentials = NULL;
78 }
79
80 status = samba_server_gensec_start(dce_conn, call->event_ctx,
81 call->msg_ctx,
82 call->conn->dce_ctx->lp_ctx,
83 server_credentials,
84 NULL,
85 &auth->gensec_security);
86
87 status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_info->auth_type,
88 auth->auth_info->auth_level);
89
90 if (!NT_STATUS_IS_OK(status)) {
91 DEBUG(1, ("Failed to start GENSEC mechanism for DCERPC server: auth_type=%d, auth_level=%d: %s\n",
92 (int)auth->auth_info->auth_type,
93 (int)auth->auth_info->auth_level,
94 nt_errstr(status)));
95 return false;
96 }
97
98 if (call->conn->state_flags & DCESRV_CALL_STATE_FLAG_HEADER_SIGNING) {
99 gensec_want_feature(auth->gensec_security, GENSEC_FEATURE_SIGN_PKT_HEADER);
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*/
109NTSTATUS dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct ncacn_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 NT_STATUS_OK;
116 }
117
118 status = gensec_update(dce_conn->auth_state.gensec_security,
119 call,
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 status;
129 }
130
131 if (dce_conn->state_flags & DCESRV_CALL_STATE_FLAG_HEADER_SIGNING) {
132 gensec_want_feature(dce_conn->auth_state.gensec_security,
133 GENSEC_FEATURE_SIGN_PKT_HEADER);
134 }
135
136 /* Now that we are authenticated, go back to the generic session key... */
137 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
138 return NT_STATUS_OK;
139 } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
140 dce_conn->auth_state.auth_info->auth_pad_length = 0;
141 dce_conn->auth_state.auth_info->auth_reserved = 0;
142 return NT_STATUS_OK;
143 } else {
144 DEBUG(2, ("Failed to start dcesrv auth negotiate: %s\n", nt_errstr(status)));
145 return status;
146 }
147}
148
149
150/*
151 process the final stage of a auth request
152*/
153bool dcesrv_auth_auth3(struct dcesrv_call_state *call)
154{
155 struct ncacn_packet *pkt = &call->pkt;
156 struct dcesrv_connection *dce_conn = call->conn;
157 NTSTATUS status;
158 enum ndr_err_code ndr_err;
159
160 /* We can't work without an existing gensec state, and an new blob to feed it */
161 if (!dce_conn->auth_state.auth_info ||
162 !dce_conn->auth_state.gensec_security ||
163 pkt->u.auth3.auth_info.length == 0) {
164 return false;
165 }
166
167 ndr_err = ndr_pull_struct_blob(&pkt->u.auth3.auth_info,
168 call, NULL,
169 dce_conn->auth_state.auth_info,
170 (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
171 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
172 return false;
173 }
174
175 /* Pass the extra data we got from the client down to gensec for processing */
176 status = gensec_update(dce_conn->auth_state.gensec_security,
177 call,
178 dce_conn->auth_state.auth_info->credentials,
179 &dce_conn->auth_state.auth_info->credentials);
180 if (NT_STATUS_IS_OK(status)) {
181 status = gensec_session_info(dce_conn->auth_state.gensec_security,
182 &dce_conn->auth_state.session_info);
183 if (!NT_STATUS_IS_OK(status)) {
184 DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
185 return false;
186 }
187 /* Now that we are authenticated, go back to the generic session key... */
188 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
189 return true;
190 } else {
191 DEBUG(4, ("dcesrv_auth_auth3: failed to authenticate: %s\n",
192 nt_errstr(status)));
193 return false;
194 }
195
196 return true;
197}
198
199/*
200 parse any auth information from a dcerpc alter request
201 return false if we can't handle the auth request for some
202 reason (in which case we send a bind_nak (is this true for here?))
203*/
204bool dcesrv_auth_alter(struct dcesrv_call_state *call)
205{
206 struct ncacn_packet *pkt = &call->pkt;
207 struct dcesrv_connection *dce_conn = call->conn;
208 enum ndr_err_code ndr_err;
209
210 /* on a pure interface change there is no auth blob */
211 if (pkt->u.alter.auth_info.length == 0) {
212 return true;
213 }
214
215 /* We can't work without an existing gensec state */
216 if (!dce_conn->auth_state.gensec_security) {
217 return false;
218 }
219
220 dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth);
221 if (!dce_conn->auth_state.auth_info) {
222 return false;
223 }
224
225 ndr_err = ndr_pull_struct_blob(&pkt->u.alter.auth_info,
226 call, NULL,
227 dce_conn->auth_state.auth_info,
228 (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
229 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
230 return false;
231 }
232
233 return true;
234}
235
236/*
237 add any auth information needed in a alter ack, and process the authentication
238 information found in the alter.
239*/
240NTSTATUS dcesrv_auth_alter_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
241{
242 struct dcesrv_connection *dce_conn = call->conn;
243 NTSTATUS status;
244
245 /* on a pure interface change there is no auth_info structure
246 setup */
247 if (!call->conn->auth_state.auth_info ||
248 dce_conn->auth_state.auth_info->credentials.length == 0) {
249 return NT_STATUS_OK;
250 }
251
252 if (!call->conn->auth_state.gensec_security) {
253 return NT_STATUS_INVALID_PARAMETER;
254 }
255
256 status = gensec_update(dce_conn->auth_state.gensec_security,
257 call,
258 dce_conn->auth_state.auth_info->credentials,
259 &dce_conn->auth_state.auth_info->credentials);
260
261 if (NT_STATUS_IS_OK(status)) {
262 status = gensec_session_info(dce_conn->auth_state.gensec_security,
263 &dce_conn->auth_state.session_info);
264 if (!NT_STATUS_IS_OK(status)) {
265 DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
266 return status;
267 }
268
269 /* Now that we are authenticated, got back to the generic session key... */
270 dce_conn->auth_state.session_key = dcesrv_generic_session_key;
271 return NT_STATUS_OK;
272 } else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
273 dce_conn->auth_state.auth_info->auth_pad_length = 0;
274 dce_conn->auth_state.auth_info->auth_reserved = 0;
275 return NT_STATUS_OK;
276 }
277
278 DEBUG(2, ("Failed to finish dcesrv auth alter_ack: %s\n", nt_errstr(status)));
279 return status;
280}
281
282/*
283 check credentials on a request
284*/
285bool dcesrv_auth_request(struct dcesrv_call_state *call, DATA_BLOB *full_packet)
286{
287 struct ncacn_packet *pkt = &call->pkt;
288 struct dcesrv_connection *dce_conn = call->conn;
289 DATA_BLOB auth_blob;
290 struct dcerpc_auth auth;
291 struct ndr_pull *ndr;
292 NTSTATUS status;
293 enum ndr_err_code ndr_err;
294 size_t hdr_size = DCERPC_REQUEST_LENGTH;
295
296 if (!dce_conn->auth_state.auth_info ||
297 !dce_conn->auth_state.gensec_security) {
298 return true;
299 }
300
301 switch (dce_conn->auth_state.auth_info->auth_level) {
302 case DCERPC_AUTH_LEVEL_PRIVACY:
303 case DCERPC_AUTH_LEVEL_INTEGRITY:
304 break;
305
306 case DCERPC_AUTH_LEVEL_CONNECT:
307 if (pkt->auth_length != 0) {
308 break;
309 }
310 return true;
311 case DCERPC_AUTH_LEVEL_NONE:
312 if (pkt->auth_length != 0) {
313 return false;
314 }
315 return true;
316
317 default:
318 return false;
319 }
320
321 auth_blob.length = 8 + pkt->auth_length;
322
323 /* check for a valid length */
324 if (pkt->u.request.stub_and_verifier.length < auth_blob.length) {
325 return false;
326 }
327
328 auth_blob.data =
329 pkt->u.request.stub_and_verifier.data +
330 pkt->u.request.stub_and_verifier.length - auth_blob.length;
331 pkt->u.request.stub_and_verifier.length -= auth_blob.length;
332
333 /* pull the auth structure */
334 ndr = ndr_pull_init_blob(&auth_blob, call, lp_iconv_convenience(call->conn->dce_ctx->lp_ctx));
335 if (!ndr) {
336 return false;
337 }
338
339 if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
340 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
341 }
342
343 if (pkt->pfc_flags & DCERPC_PFC_FLAG_OBJECT_UUID) {
344 ndr->flags |= LIBNDR_FLAG_OBJECT_PRESENT;
345 hdr_size += 16;
346 }
347
348 ndr_err = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, &auth);
349 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
350 talloc_free(ndr);
351 return false;
352 }
353
354 /* check signature or unseal the packet */
355 switch (dce_conn->auth_state.auth_info->auth_level) {
356 case DCERPC_AUTH_LEVEL_PRIVACY:
357 status = gensec_unseal_packet(dce_conn->auth_state.gensec_security,
358 call,
359 full_packet->data + hdr_size,
360 pkt->u.request.stub_and_verifier.length,
361 full_packet->data,
362 full_packet->length-auth.credentials.length,
363 &auth.credentials);
364 memcpy(pkt->u.request.stub_and_verifier.data,
365 full_packet->data + hdr_size,
366 pkt->u.request.stub_and_verifier.length);
367 break;
368
369 case DCERPC_AUTH_LEVEL_INTEGRITY:
370 status = gensec_check_packet(dce_conn->auth_state.gensec_security,
371 call,
372 pkt->u.request.stub_and_verifier.data,
373 pkt->u.request.stub_and_verifier.length,
374 full_packet->data,
375 full_packet->length-auth.credentials.length,
376 &auth.credentials);
377 break;
378
379 case DCERPC_AUTH_LEVEL_CONNECT:
380 /* for now we ignore possible signatures here */
381 status = NT_STATUS_OK;
382 break;
383
384 default:
385 status = NT_STATUS_INVALID_LEVEL;
386 break;
387 }
388
389 /* remove the indicated amount of padding */
390 if (pkt->u.request.stub_and_verifier.length < auth.auth_pad_length) {
391 talloc_free(ndr);
392 return false;
393 }
394 pkt->u.request.stub_and_verifier.length -= auth.auth_pad_length;
395 talloc_free(ndr);
396
397 return NT_STATUS_IS_OK(status);
398}
399
400
401/*
402 push a signed or sealed dcerpc request packet into a blob
403*/
404bool dcesrv_auth_response(struct dcesrv_call_state *call,
405 DATA_BLOB *blob, size_t sig_size,
406 struct ncacn_packet *pkt)
407{
408 struct dcesrv_connection *dce_conn = call->conn;
409 NTSTATUS status;
410 enum ndr_err_code ndr_err;
411 struct ndr_push *ndr;
412 uint32_t payload_length;
413 DATA_BLOB creds2;
414
415 /* non-signed packets are simple */
416 if (sig_size == 0) {
417 status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL);
418 return NT_STATUS_IS_OK(status);
419 }
420
421 switch (dce_conn->auth_state.auth_info->auth_level) {
422 case DCERPC_AUTH_LEVEL_PRIVACY:
423 case DCERPC_AUTH_LEVEL_INTEGRITY:
424 break;
425
426 case DCERPC_AUTH_LEVEL_CONNECT:
427 /*
428 * TODO: let the gensec mech decide if it wants to generate a signature
429 * that might be needed for schannel...
430 */
431 status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL);
432 return NT_STATUS_IS_OK(status);
433
434 case DCERPC_AUTH_LEVEL_NONE:
435 status = ncacn_push_auth(blob, call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx), pkt, NULL);
436 return NT_STATUS_IS_OK(status);
437
438 default:
439 return false;
440 }
441
442 ndr = ndr_push_init_ctx(call, lp_iconv_convenience(dce_conn->dce_ctx->lp_ctx));
443 if (!ndr) {
444 return false;
445 }
446
447 if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
448 ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
449 }
450
451 ndr_err = ndr_push_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
452 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
453 return false;
454 }
455
456 /* pad to 16 byte multiple, match win2k3 */
457 dce_conn->auth_state.auth_info->auth_pad_length =
458 (16 - (pkt->u.response.stub_and_verifier.length & 15)) & 15;
459 ndr_err = ndr_push_zero(ndr, dce_conn->auth_state.auth_info->auth_pad_length);
460 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
461 return false;
462 }
463
464 payload_length = pkt->u.response.stub_and_verifier.length +
465 dce_conn->auth_state.auth_info->auth_pad_length;
466
467 /* we start without signature, it will appended later */
468 dce_conn->auth_state.auth_info->credentials = data_blob(NULL, 0);
469
470 /* add the auth verifier */
471 ndr_err = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS,
472 dce_conn->auth_state.auth_info);
473 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
474 return false;
475 }
476
477 /* extract the whole packet as a blob */
478 *blob = ndr_push_blob(ndr);
479
480 /*
481 * Setup the frag and auth length in the packet buffer.
482 * This is needed if the GENSEC mech does AEAD signing
483 * of the packet headers. The signature itself will be
484 * appended later.
485 */
486 dcerpc_set_frag_length(blob, blob->length + sig_size);
487 dcerpc_set_auth_length(blob, sig_size);
488
489 /* sign or seal the packet */
490 switch (dce_conn->auth_state.auth_info->auth_level) {
491 case DCERPC_AUTH_LEVEL_PRIVACY:
492 status = gensec_seal_packet(dce_conn->auth_state.gensec_security,
493 call,
494 ndr->data + DCERPC_REQUEST_LENGTH,
495 payload_length,
496 blob->data,
497 blob->length,
498 &creds2);
499 break;
500
501 case DCERPC_AUTH_LEVEL_INTEGRITY:
502 status = gensec_sign_packet(dce_conn->auth_state.gensec_security,
503 call,
504 ndr->data + DCERPC_REQUEST_LENGTH,
505 payload_length,
506 blob->data,
507 blob->length,
508 &creds2);
509 break;
510
511 default:
512 status = NT_STATUS_INVALID_LEVEL;
513 break;
514 }
515
516 if (NT_STATUS_IS_OK(status)) {
517 if (creds2.length != sig_size) {
518 DEBUG(0,("dcesrv_auth_response: creds2.length[%u] != sig_size[%u] pad[%u] stub[%u]\n",
519 (unsigned)creds2.length, (uint32_t)sig_size,
520 (unsigned)dce_conn->auth_state.auth_info->auth_pad_length,
521 (unsigned)pkt->u.response.stub_and_verifier.length));
522 data_blob_free(&creds2);
523 status = NT_STATUS_INTERNAL_ERROR;
524 }
525 }
526
527 if (NT_STATUS_IS_OK(status)) {
528 if (!data_blob_append(call, blob, creds2.data, creds2.length)) {
529 status = NT_STATUS_NO_MEMORY;
530 }
531 data_blob_free(&creds2);
532 }
533
534 if (!NT_STATUS_IS_OK(status)) {
535 return false;
536 }
537
538 return true;
539}
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