source: vendor/3.5.0/source3/libsmb/clispnego.c

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

Samba 3.5.0: Initial import
File size: 14.7 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 simple kerberos5/SPNEGO routines
4 Copyright (C) Andrew Tridgell 2001
5 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
6 Copyright (C) Luke Howard 2003
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20*/
21
22#include "includes.h"
23#include "../libcli/auth/spnego.h"
24#include "smb_krb5.h"
25
26/*
27 generate a negTokenInit packet given a GUID, a list of supported
28 OIDs (the mechanisms) and a principal name string
29*/
30DATA_BLOB spnego_gen_negTokenInit(char guid[16],
31 const char *OIDs[],
32 const char *principal)
33{
34 int i;
35 ASN1_DATA *data;
36 DATA_BLOB ret;
37
38 data = asn1_init(talloc_tos());
39 if (data == NULL) {
40 return data_blob_null;
41 }
42
43 asn1_write(data, guid, 16);
44 asn1_push_tag(data,ASN1_APPLICATION(0));
45 asn1_write_OID(data,OID_SPNEGO);
46 asn1_push_tag(data,ASN1_CONTEXT(0));
47 asn1_push_tag(data,ASN1_SEQUENCE(0));
48
49 asn1_push_tag(data,ASN1_CONTEXT(0));
50 asn1_push_tag(data,ASN1_SEQUENCE(0));
51 for (i=0; OIDs[i]; i++) {
52 asn1_write_OID(data,OIDs[i]);
53 }
54 asn1_pop_tag(data);
55 asn1_pop_tag(data);
56
57 asn1_push_tag(data, ASN1_CONTEXT(3));
58 asn1_push_tag(data, ASN1_SEQUENCE(0));
59 asn1_push_tag(data, ASN1_CONTEXT(0));
60 asn1_write_GeneralString(data,principal);
61 asn1_pop_tag(data);
62 asn1_pop_tag(data);
63 asn1_pop_tag(data);
64
65 asn1_pop_tag(data);
66 asn1_pop_tag(data);
67
68 asn1_pop_tag(data);
69
70 if (data->has_error) {
71 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
72 }
73
74 ret = data_blob(data->data, data->length);
75 asn1_free(data);
76
77 return ret;
78}
79
80/*
81 Generate a negTokenInit as used by the client side ... It has a mechType
82 (OID), and a mechToken (a security blob) ...
83
84 Really, we need to break out the NTLMSSP stuff as well, because it could be
85 raw in the packets!
86*/
87DATA_BLOB gen_negTokenInit(const char *OID, DATA_BLOB blob)
88{
89 ASN1_DATA *data;
90 DATA_BLOB ret;
91
92 data = asn1_init(talloc_tos());
93 if (data == NULL) {
94 return data_blob_null;
95 }
96
97 asn1_push_tag(data, ASN1_APPLICATION(0));
98 asn1_write_OID(data,OID_SPNEGO);
99 asn1_push_tag(data, ASN1_CONTEXT(0));
100 asn1_push_tag(data, ASN1_SEQUENCE(0));
101
102 asn1_push_tag(data, ASN1_CONTEXT(0));
103 asn1_push_tag(data, ASN1_SEQUENCE(0));
104 asn1_write_OID(data, OID);
105 asn1_pop_tag(data);
106 asn1_pop_tag(data);
107
108 asn1_push_tag(data, ASN1_CONTEXT(2));
109 asn1_write_OctetString(data,blob.data,blob.length);
110 asn1_pop_tag(data);
111
112 asn1_pop_tag(data);
113 asn1_pop_tag(data);
114
115 asn1_pop_tag(data);
116
117 if (data->has_error) {
118 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
119 }
120
121 ret = data_blob(data->data, data->length);
122 asn1_free(data);
123
124 return ret;
125}
126
127/*
128 parse a negTokenInit packet giving a GUID, a list of supported
129 OIDs (the mechanisms) and a principal name string
130*/
131bool spnego_parse_negTokenInit(DATA_BLOB blob,
132 char *OIDs[ASN1_MAX_OIDS],
133 char **principal)
134{
135 int i;
136 bool ret;
137 ASN1_DATA *data;
138
139 data = asn1_init(talloc_tos());
140 if (data == NULL) {
141 return false;
142 }
143
144 asn1_load(data, blob);
145
146 asn1_start_tag(data,ASN1_APPLICATION(0));
147
148 asn1_check_OID(data,OID_SPNEGO);
149 asn1_start_tag(data,ASN1_CONTEXT(0));
150 asn1_start_tag(data,ASN1_SEQUENCE(0));
151
152 asn1_start_tag(data,ASN1_CONTEXT(0));
153 asn1_start_tag(data,ASN1_SEQUENCE(0));
154 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
155 const char *oid_str = NULL;
156 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
157 OIDs[i] = CONST_DISCARD(char *, oid_str);
158 }
159 OIDs[i] = NULL;
160 asn1_end_tag(data);
161 asn1_end_tag(data);
162
163 *principal = NULL;
164 if (asn1_tag_remaining(data) > 0) {
165 asn1_start_tag(data, ASN1_CONTEXT(3));
166 asn1_start_tag(data, ASN1_SEQUENCE(0));
167 asn1_start_tag(data, ASN1_CONTEXT(0));
168 asn1_read_GeneralString(data,talloc_autofree_context(),principal);
169 asn1_end_tag(data);
170 asn1_end_tag(data);
171 asn1_end_tag(data);
172 }
173
174 asn1_end_tag(data);
175 asn1_end_tag(data);
176
177 asn1_end_tag(data);
178
179 ret = !data->has_error;
180 if (data->has_error) {
181 int j;
182 TALLOC_FREE(*principal);
183 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
184 TALLOC_FREE(OIDs[j]);
185 }
186 }
187
188 asn1_free(data);
189 return ret;
190}
191
192/*
193 generate a negTokenTarg packet given a list of OIDs and a security blob
194*/
195DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob)
196{
197 int i;
198 ASN1_DATA *data;
199 DATA_BLOB ret;
200
201 data = asn1_init(talloc_tos());
202 if (data == NULL) {
203 return data_blob_null;
204 }
205
206 asn1_push_tag(data, ASN1_APPLICATION(0));
207 asn1_write_OID(data,OID_SPNEGO);
208 asn1_push_tag(data, ASN1_CONTEXT(0));
209 asn1_push_tag(data, ASN1_SEQUENCE(0));
210
211 asn1_push_tag(data, ASN1_CONTEXT(0));
212 asn1_push_tag(data, ASN1_SEQUENCE(0));
213 for (i=0; OIDs[i]; i++) {
214 asn1_write_OID(data,OIDs[i]);
215 }
216 asn1_pop_tag(data);
217 asn1_pop_tag(data);
218
219 asn1_push_tag(data, ASN1_CONTEXT(2));
220 asn1_write_OctetString(data,blob.data,blob.length);
221 asn1_pop_tag(data);
222
223 asn1_pop_tag(data);
224 asn1_pop_tag(data);
225
226 asn1_pop_tag(data);
227
228 if (data->has_error) {
229 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs));
230 }
231
232 ret = data_blob(data->data, data->length);
233 asn1_free(data);
234
235 return ret;
236}
237
238/*
239 parse a negTokenTarg packet giving a list of OIDs and a security blob
240*/
241bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob)
242{
243 int i;
244 ASN1_DATA *data;
245
246 data = asn1_init(talloc_tos());
247 if (data == NULL) {
248 return false;
249 }
250
251 asn1_load(data, blob);
252 asn1_start_tag(data, ASN1_APPLICATION(0));
253 asn1_check_OID(data,OID_SPNEGO);
254 asn1_start_tag(data, ASN1_CONTEXT(0));
255 asn1_start_tag(data, ASN1_SEQUENCE(0));
256
257 asn1_start_tag(data, ASN1_CONTEXT(0));
258 asn1_start_tag(data, ASN1_SEQUENCE(0));
259 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
260 const char *oid_str = NULL;
261 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
262 OIDs[i] = CONST_DISCARD(char *, oid_str);
263 }
264 OIDs[i] = NULL;
265 asn1_end_tag(data);
266 asn1_end_tag(data);
267
268 /* Skip any optional req_flags that are sent per RFC 4178 */
269 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
270 uint8 flags;
271
272 asn1_start_tag(data, ASN1_CONTEXT(1));
273 asn1_start_tag(data, ASN1_BIT_STRING);
274 while (asn1_tag_remaining(data) > 0)
275 asn1_read_uint8(data, &flags);
276 asn1_end_tag(data);
277 asn1_end_tag(data);
278 }
279
280 asn1_start_tag(data, ASN1_CONTEXT(2));
281 asn1_read_OctetString(data,talloc_autofree_context(),secblob);
282 asn1_end_tag(data);
283
284 asn1_end_tag(data);
285 asn1_end_tag(data);
286
287 asn1_end_tag(data);
288
289 if (data->has_error) {
290 int j;
291 data_blob_free(secblob);
292 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
293 TALLOC_FREE(OIDs[j]);
294 }
295 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs));
296 asn1_free(data);
297 return False;
298 }
299
300 asn1_free(data);
301 return True;
302}
303
304/*
305 generate a krb5 GSS-API wrapper packet given a ticket
306*/
307DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2])
308{
309 ASN1_DATA *data;
310 DATA_BLOB ret;
311
312 data = asn1_init(talloc_tos());
313 if (data == NULL) {
314 return data_blob_null;
315 }
316
317 asn1_push_tag(data, ASN1_APPLICATION(0));
318 asn1_write_OID(data, OID_KERBEROS5);
319
320 asn1_write(data, tok_id, 2);
321 asn1_write(data, ticket.data, ticket.length);
322 asn1_pop_tag(data);
323
324 if (data->has_error) {
325 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
326 }
327
328 ret = data_blob(data->data, data->length);
329 asn1_free(data);
330
331 return ret;
332}
333
334/*
335 parse a krb5 GSS-API wrapper packet giving a ticket
336*/
337bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
338{
339 bool ret;
340 ASN1_DATA *data;
341 int data_remaining;
342
343 data = asn1_init(talloc_tos());
344 if (data == NULL) {
345 return false;
346 }
347
348 asn1_load(data, blob);
349 asn1_start_tag(data, ASN1_APPLICATION(0));
350 asn1_check_OID(data, OID_KERBEROS5);
351
352 data_remaining = asn1_tag_remaining(data);
353
354 if (data_remaining < 3) {
355 data->has_error = True;
356 } else {
357 asn1_read(data, tok_id, 2);
358 data_remaining -= 2;
359 *ticket = data_blob(NULL, data_remaining);
360 asn1_read(data, ticket->data, ticket->length);
361 }
362
363 asn1_end_tag(data);
364
365 ret = !data->has_error;
366
367 if (data->has_error) {
368 data_blob_free(ticket);
369 }
370
371 asn1_free(data);
372
373 return ret;
374}
375
376
377/*
378 generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY
379 kerberos session setup
380*/
381int spnego_gen_negTokenTarg(const char *principal, int time_offset,
382 DATA_BLOB *targ,
383 DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
384 time_t *expire_time)
385{
386 int retval;
387 DATA_BLOB tkt, tkt_wrapped;
388 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
389
390 /* get a kerberos ticket for the service and extract the session key */
391 retval = cli_krb5_get_ticket(principal, time_offset,
392 &tkt, session_key_krb5, extra_ap_opts, NULL,
393 expire_time, NULL);
394
395 if (retval)
396 return retval;
397
398 /* wrap that up in a nice GSS-API wrapping */
399 tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
400
401 /* and wrap that in a shiny SPNEGO wrapper */
402 *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
403
404 data_blob_free(&tkt_wrapped);
405 data_blob_free(&tkt);
406
407 return retval;
408}
409
410
411/*
412 parse a spnego NTLMSSP challenge packet giving two security blobs
413*/
414bool spnego_parse_challenge(const DATA_BLOB blob,
415 DATA_BLOB *chal1, DATA_BLOB *chal2)
416{
417 bool ret;
418 ASN1_DATA *data;
419
420 ZERO_STRUCTP(chal1);
421 ZERO_STRUCTP(chal2);
422
423 data = asn1_init(talloc_tos());
424 if (data == NULL) {
425 return false;
426 }
427
428 asn1_load(data, blob);
429 asn1_start_tag(data,ASN1_CONTEXT(1));
430 asn1_start_tag(data,ASN1_SEQUENCE(0));
431
432 asn1_start_tag(data,ASN1_CONTEXT(0));
433 asn1_check_enumerated(data,1);
434 asn1_end_tag(data);
435
436 asn1_start_tag(data,ASN1_CONTEXT(1));
437 asn1_check_OID(data, OID_NTLMSSP);
438 asn1_end_tag(data);
439
440 asn1_start_tag(data,ASN1_CONTEXT(2));
441 asn1_read_OctetString(data, talloc_autofree_context(), chal1);
442 asn1_end_tag(data);
443
444 /* the second challenge is optional (XP doesn't send it) */
445 if (asn1_tag_remaining(data)) {
446 asn1_start_tag(data,ASN1_CONTEXT(3));
447 asn1_read_OctetString(data, talloc_autofree_context(), chal2);
448 asn1_end_tag(data);
449 }
450
451 asn1_end_tag(data);
452 asn1_end_tag(data);
453
454 ret = !data->has_error;
455
456 if (data->has_error) {
457 data_blob_free(chal1);
458 data_blob_free(chal2);
459 }
460
461 asn1_free(data);
462 return ret;
463}
464
465
466/*
467 generate a SPNEGO auth packet. This will contain the encrypted passwords
468*/
469DATA_BLOB spnego_gen_auth(DATA_BLOB blob)
470{
471 ASN1_DATA *data;
472 DATA_BLOB ret;
473
474 data = asn1_init(talloc_tos());
475 if (data == NULL) {
476 return data_blob_null;
477 }
478
479 asn1_push_tag(data, ASN1_CONTEXT(1));
480 asn1_push_tag(data, ASN1_SEQUENCE(0));
481 asn1_push_tag(data, ASN1_CONTEXT(2));
482 asn1_write_OctetString(data,blob.data,blob.length);
483 asn1_pop_tag(data);
484 asn1_pop_tag(data);
485 asn1_pop_tag(data);
486
487 ret = data_blob(data->data, data->length);
488
489 asn1_free(data);
490
491 return ret;
492}
493
494/*
495 parse a SPNEGO auth packet. This contains the encrypted passwords
496*/
497bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
498{
499 ssize_t len;
500 struct spnego_data token;
501
502 len = spnego_read_data(talloc_tos(), blob, &token);
503 if (len == -1) {
504 DEBUG(3,("spnego_parse_auth: spnego_read_data failed\n"));
505 return false;
506 }
507
508 if (token.type != SPNEGO_NEG_TOKEN_TARG) {
509 DEBUG(3,("spnego_parse_auth: wrong token type: %d\n",
510 token.type));
511 spnego_free_data(&token);
512 return false;
513 }
514
515 *auth = data_blob_talloc(talloc_tos(),
516 token.negTokenTarg.responseToken.data,
517 token.negTokenTarg.responseToken.length);
518 spnego_free_data(&token);
519
520 return true;
521}
522
523/*
524 generate a minimal SPNEGO response packet. Doesn't contain much.
525*/
526DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
527 const char *mechOID)
528{
529 ASN1_DATA *data;
530 DATA_BLOB ret;
531 uint8 negResult;
532
533 if (NT_STATUS_IS_OK(nt_status)) {
534 negResult = SPNEGO_ACCEPT_COMPLETED;
535 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
536 negResult = SPNEGO_ACCEPT_INCOMPLETE;
537 } else {
538 negResult = SPNEGO_REJECT;
539 }
540
541 data = asn1_init(talloc_tos());
542 if (data == NULL) {
543 return data_blob_null;
544 }
545
546 asn1_push_tag(data, ASN1_CONTEXT(1));
547 asn1_push_tag(data, ASN1_SEQUENCE(0));
548 asn1_push_tag(data, ASN1_CONTEXT(0));
549 asn1_write_enumerated(data, negResult);
550 asn1_pop_tag(data);
551
552 if (mechOID) {
553 asn1_push_tag(data,ASN1_CONTEXT(1));
554 asn1_write_OID(data, mechOID);
555 asn1_pop_tag(data);
556 }
557
558 if (reply && reply->data != NULL) {
559 asn1_push_tag(data,ASN1_CONTEXT(2));
560 asn1_write_OctetString(data, reply->data, reply->length);
561 asn1_pop_tag(data);
562 }
563
564 asn1_pop_tag(data);
565 asn1_pop_tag(data);
566
567 ret = data_blob(data->data, data->length);
568 asn1_free(data);
569 return ret;
570}
571
572/*
573 parse a SPNEGO auth packet. This contains the encrypted passwords
574*/
575bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
576 const char *mechOID,
577 DATA_BLOB *auth)
578{
579 ASN1_DATA *data;
580 uint8 negResult;
581
582 if (NT_STATUS_IS_OK(nt_status)) {
583 negResult = SPNEGO_ACCEPT_COMPLETED;
584 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
585 negResult = SPNEGO_ACCEPT_INCOMPLETE;
586 } else {
587 negResult = SPNEGO_REJECT;
588 }
589
590 data = asn1_init(talloc_tos());
591 if (data == NULL) {
592 return false;
593 }
594
595 asn1_load(data, blob);
596 asn1_start_tag(data, ASN1_CONTEXT(1));
597 asn1_start_tag(data, ASN1_SEQUENCE(0));
598 asn1_start_tag(data, ASN1_CONTEXT(0));
599 asn1_check_enumerated(data, negResult);
600 asn1_end_tag(data);
601
602 *auth = data_blob_null;
603
604 if (asn1_tag_remaining(data)) {
605 asn1_start_tag(data,ASN1_CONTEXT(1));
606 asn1_check_OID(data, mechOID);
607 asn1_end_tag(data);
608
609 if (asn1_tag_remaining(data)) {
610 asn1_start_tag(data,ASN1_CONTEXT(2));
611 asn1_read_OctetString(data, talloc_autofree_context(), auth);
612 asn1_end_tag(data);
613 }
614 } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
615 data->has_error = 1;
616 }
617
618 /* Binding against Win2K DC returns a duplicate of the responseToken in
619 * the optional mechListMIC field. This is a bug in Win2K. We ignore
620 * this field if it exists. Win2K8 may return a proper mechListMIC at
621 * which point we need to implement the integrity checking. */
622 if (asn1_tag_remaining(data)) {
623 DATA_BLOB mechList = data_blob_null;
624 asn1_start_tag(data, ASN1_CONTEXT(3));
625 asn1_read_OctetString(data, talloc_autofree_context(), &mechList);
626 asn1_end_tag(data);
627 data_blob_free(&mechList);
628 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
629 "ignoring.\n"));
630 }
631
632 asn1_end_tag(data);
633 asn1_end_tag(data);
634
635 if (data->has_error) {
636 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
637 asn1_free(data);
638 data_blob_free(auth);
639 return False;
640 }
641
642 asn1_free(data);
643 return True;
644}
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