source: branches/samba-3.5.x/source3/libsmb/clispnego.c@ 734

Last change on this file since 734 was 590, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update trunk to 3.5.6
File size: 16.4 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
150 /* negTokenInit [0] NegTokenInit */
151 asn1_start_tag(data,ASN1_CONTEXT(0));
152 asn1_start_tag(data,ASN1_SEQUENCE(0));
153
154 /* mechTypes [0] MechTypeList OPTIONAL */
155
156 /* Not really optional, we depend on this to decide
157 * what mechanisms we have to work with. */
158
159 asn1_start_tag(data,ASN1_CONTEXT(0));
160 asn1_start_tag(data,ASN1_SEQUENCE(0));
161 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
162 const char *oid_str = NULL;
163 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
164 OIDs[i] = CONST_DISCARD(char *, oid_str);
165 }
166 OIDs[i] = NULL;
167 asn1_end_tag(data);
168 asn1_end_tag(data);
169
170 *principal = NULL;
171
172 /*
173 Win7 + Live Sign-in Assistant attaches a mechToken
174 ASN1_CONTEXT(2) to the negTokenInit packet
175 which breaks our negotiation if we just assume
176 the next tag is ASN1_CONTEXT(3).
177 */
178
179 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
180 uint8 flags;
181
182 /* reqFlags [1] ContextFlags OPTIONAL */
183 asn1_start_tag(data, ASN1_CONTEXT(1));
184 asn1_start_tag(data, ASN1_BIT_STRING);
185 while (asn1_tag_remaining(data) > 0) {
186 asn1_read_uint8(data, &flags);
187 }
188 asn1_end_tag(data);
189 asn1_end_tag(data);
190 }
191
192 if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
193 /* mechToken [2] OCTET STRING OPTIONAL */
194 DATA_BLOB token;
195 asn1_start_tag(data, ASN1_CONTEXT(2));
196 asn1_read_OctetString(data, talloc_autofree_context(),
197 &token);
198 asn1_end_tag(data);
199 /* Throw away the token - not used. */
200 data_blob_free(&token);
201 }
202
203 if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
204 /* mechListMIC [3] OCTET STRING OPTIONAL */
205 asn1_start_tag(data, ASN1_CONTEXT(3));
206 asn1_start_tag(data, ASN1_SEQUENCE(0));
207 asn1_start_tag(data, ASN1_CONTEXT(0));
208 asn1_read_GeneralString(data,talloc_autofree_context(),
209 principal);
210 asn1_end_tag(data);
211 asn1_end_tag(data);
212 asn1_end_tag(data);
213 }
214
215 asn1_end_tag(data);
216 asn1_end_tag(data);
217
218 asn1_end_tag(data);
219
220 ret = !data->has_error;
221 if (data->has_error) {
222 int j;
223 TALLOC_FREE(*principal);
224 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
225 TALLOC_FREE(OIDs[j]);
226 }
227 }
228
229 asn1_free(data);
230 return ret;
231}
232
233/*
234 generate a negTokenTarg packet given a list of OIDs and a security blob
235*/
236DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob)
237{
238 int i;
239 ASN1_DATA *data;
240 DATA_BLOB ret;
241
242 data = asn1_init(talloc_tos());
243 if (data == NULL) {
244 return data_blob_null;
245 }
246
247 asn1_push_tag(data, ASN1_APPLICATION(0));
248 asn1_write_OID(data,OID_SPNEGO);
249 asn1_push_tag(data, ASN1_CONTEXT(0));
250 asn1_push_tag(data, ASN1_SEQUENCE(0));
251
252 asn1_push_tag(data, ASN1_CONTEXT(0));
253 asn1_push_tag(data, ASN1_SEQUENCE(0));
254 for (i=0; OIDs[i]; i++) {
255 asn1_write_OID(data,OIDs[i]);
256 }
257 asn1_pop_tag(data);
258 asn1_pop_tag(data);
259
260 asn1_push_tag(data, ASN1_CONTEXT(2));
261 asn1_write_OctetString(data,blob.data,blob.length);
262 asn1_pop_tag(data);
263
264 asn1_pop_tag(data);
265 asn1_pop_tag(data);
266
267 asn1_pop_tag(data);
268
269 if (data->has_error) {
270 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs));
271 }
272
273 ret = data_blob(data->data, data->length);
274 asn1_free(data);
275
276 return ret;
277}
278
279/*
280 parse a negTokenTarg packet giving a list of OIDs and a security blob
281*/
282bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob)
283{
284 int i;
285 ASN1_DATA *data;
286
287 data = asn1_init(talloc_tos());
288 if (data == NULL) {
289 return false;
290 }
291
292 asn1_load(data, blob);
293 asn1_start_tag(data, ASN1_APPLICATION(0));
294 asn1_check_OID(data,OID_SPNEGO);
295 asn1_start_tag(data, ASN1_CONTEXT(0));
296 asn1_start_tag(data, ASN1_SEQUENCE(0));
297
298 asn1_start_tag(data, ASN1_CONTEXT(0));
299 asn1_start_tag(data, ASN1_SEQUENCE(0));
300 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
301 const char *oid_str = NULL;
302 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
303 OIDs[i] = CONST_DISCARD(char *, oid_str);
304 }
305 OIDs[i] = NULL;
306 asn1_end_tag(data);
307 asn1_end_tag(data);
308
309 /* Skip any optional req_flags that are sent per RFC 4178 */
310 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
311 uint8 flags;
312
313 asn1_start_tag(data, ASN1_CONTEXT(1));
314 asn1_start_tag(data, ASN1_BIT_STRING);
315 while (asn1_tag_remaining(data) > 0)
316 asn1_read_uint8(data, &flags);
317 asn1_end_tag(data);
318 asn1_end_tag(data);
319 }
320
321 asn1_start_tag(data, ASN1_CONTEXT(2));
322 asn1_read_OctetString(data,talloc_autofree_context(),secblob);
323 asn1_end_tag(data);
324
325 asn1_end_tag(data);
326 asn1_end_tag(data);
327
328 asn1_end_tag(data);
329
330 if (data->has_error) {
331 int j;
332 data_blob_free(secblob);
333 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
334 TALLOC_FREE(OIDs[j]);
335 }
336 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs));
337 asn1_free(data);
338 return False;
339 }
340
341 asn1_free(data);
342 return True;
343}
344
345/*
346 generate a krb5 GSS-API wrapper packet given a ticket
347*/
348DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2])
349{
350 ASN1_DATA *data;
351 DATA_BLOB ret;
352
353 data = asn1_init(talloc_tos());
354 if (data == NULL) {
355 return data_blob_null;
356 }
357
358 asn1_push_tag(data, ASN1_APPLICATION(0));
359 asn1_write_OID(data, OID_KERBEROS5);
360
361 asn1_write(data, tok_id, 2);
362 asn1_write(data, ticket.data, ticket.length);
363 asn1_pop_tag(data);
364
365 if (data->has_error) {
366 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
367 }
368
369 ret = data_blob(data->data, data->length);
370 asn1_free(data);
371
372 return ret;
373}
374
375/*
376 parse a krb5 GSS-API wrapper packet giving a ticket
377*/
378bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
379{
380 bool ret;
381 ASN1_DATA *data;
382 int data_remaining;
383
384 data = asn1_init(talloc_tos());
385 if (data == NULL) {
386 return false;
387 }
388
389 asn1_load(data, blob);
390 asn1_start_tag(data, ASN1_APPLICATION(0));
391 asn1_check_OID(data, OID_KERBEROS5);
392
393 data_remaining = asn1_tag_remaining(data);
394
395 if (data_remaining < 3) {
396 data->has_error = True;
397 } else {
398 asn1_read(data, tok_id, 2);
399 data_remaining -= 2;
400 *ticket = data_blob(NULL, data_remaining);
401 asn1_read(data, ticket->data, ticket->length);
402 }
403
404 asn1_end_tag(data);
405
406 ret = !data->has_error;
407
408 if (data->has_error) {
409 data_blob_free(ticket);
410 }
411
412 asn1_free(data);
413
414 return ret;
415}
416
417
418/*
419 generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY
420 kerberos session setup
421*/
422int spnego_gen_negTokenTarg(const char *principal, int time_offset,
423 DATA_BLOB *targ,
424 DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
425 time_t *expire_time)
426{
427 int retval;
428 DATA_BLOB tkt, tkt_wrapped;
429 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
430
431 /* get a kerberos ticket for the service and extract the session key */
432 retval = cli_krb5_get_ticket(principal, time_offset,
433 &tkt, session_key_krb5, extra_ap_opts, NULL,
434 expire_time, NULL);
435
436 if (retval)
437 return retval;
438
439 /* wrap that up in a nice GSS-API wrapping */
440 tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
441
442 /* and wrap that in a shiny SPNEGO wrapper */
443 *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
444
445 data_blob_free(&tkt_wrapped);
446 data_blob_free(&tkt);
447
448 return retval;
449}
450
451
452/*
453 parse a spnego NTLMSSP challenge packet giving two security blobs
454*/
455bool spnego_parse_challenge(const DATA_BLOB blob,
456 DATA_BLOB *chal1, DATA_BLOB *chal2)
457{
458 bool ret;
459 ASN1_DATA *data;
460
461 ZERO_STRUCTP(chal1);
462 ZERO_STRUCTP(chal2);
463
464 data = asn1_init(talloc_tos());
465 if (data == NULL) {
466 return false;
467 }
468
469 asn1_load(data, blob);
470 asn1_start_tag(data,ASN1_CONTEXT(1));
471 asn1_start_tag(data,ASN1_SEQUENCE(0));
472
473 asn1_start_tag(data,ASN1_CONTEXT(0));
474 asn1_check_enumerated(data,1);
475 asn1_end_tag(data);
476
477 asn1_start_tag(data,ASN1_CONTEXT(1));
478 asn1_check_OID(data, OID_NTLMSSP);
479 asn1_end_tag(data);
480
481 asn1_start_tag(data,ASN1_CONTEXT(2));
482 asn1_read_OctetString(data, talloc_autofree_context(), chal1);
483 asn1_end_tag(data);
484
485 /* the second challenge is optional (XP doesn't send it) */
486 if (asn1_tag_remaining(data)) {
487 asn1_start_tag(data,ASN1_CONTEXT(3));
488 asn1_read_OctetString(data, talloc_autofree_context(), chal2);
489 asn1_end_tag(data);
490 }
491
492 asn1_end_tag(data);
493 asn1_end_tag(data);
494
495 ret = !data->has_error;
496
497 if (data->has_error) {
498 data_blob_free(chal1);
499 data_blob_free(chal2);
500 }
501
502 asn1_free(data);
503 return ret;
504}
505
506
507/*
508 generate a SPNEGO auth packet. This will contain the encrypted passwords
509*/
510DATA_BLOB spnego_gen_auth(DATA_BLOB blob)
511{
512 ASN1_DATA *data;
513 DATA_BLOB ret;
514
515 data = asn1_init(talloc_tos());
516 if (data == NULL) {
517 return data_blob_null;
518 }
519
520 asn1_push_tag(data, ASN1_CONTEXT(1));
521 asn1_push_tag(data, ASN1_SEQUENCE(0));
522 asn1_push_tag(data, ASN1_CONTEXT(2));
523 asn1_write_OctetString(data,blob.data,blob.length);
524 asn1_pop_tag(data);
525 asn1_pop_tag(data);
526 asn1_pop_tag(data);
527
528 ret = data_blob(data->data, data->length);
529
530 asn1_free(data);
531
532 return ret;
533}
534
535/*
536 parse a SPNEGO auth packet. This contains the encrypted passwords
537*/
538bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
539{
540 ssize_t len;
541 struct spnego_data token;
542
543 len = spnego_read_data(talloc_tos(), blob, &token);
544 if (len == -1) {
545 DEBUG(3,("spnego_parse_auth: spnego_read_data failed\n"));
546 return false;
547 }
548
549 if (token.type != SPNEGO_NEG_TOKEN_TARG) {
550 DEBUG(3,("spnego_parse_auth: wrong token type: %d\n",
551 token.type));
552 spnego_free_data(&token);
553 return false;
554 }
555
556 *auth = data_blob_talloc(talloc_tos(),
557 token.negTokenTarg.responseToken.data,
558 token.negTokenTarg.responseToken.length);
559 spnego_free_data(&token);
560
561 return true;
562}
563
564/*
565 generate a minimal SPNEGO response packet. Doesn't contain much.
566*/
567DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
568 const char *mechOID)
569{
570 ASN1_DATA *data;
571 DATA_BLOB ret;
572 uint8 negResult;
573
574 if (NT_STATUS_IS_OK(nt_status)) {
575 negResult = SPNEGO_ACCEPT_COMPLETED;
576 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
577 negResult = SPNEGO_ACCEPT_INCOMPLETE;
578 } else {
579 negResult = SPNEGO_REJECT;
580 }
581
582 data = asn1_init(talloc_tos());
583 if (data == NULL) {
584 return data_blob_null;
585 }
586
587 asn1_push_tag(data, ASN1_CONTEXT(1));
588 asn1_push_tag(data, ASN1_SEQUENCE(0));
589 asn1_push_tag(data, ASN1_CONTEXT(0));
590 asn1_write_enumerated(data, negResult);
591 asn1_pop_tag(data);
592
593 if (mechOID) {
594 asn1_push_tag(data,ASN1_CONTEXT(1));
595 asn1_write_OID(data, mechOID);
596 asn1_pop_tag(data);
597 }
598
599 if (reply && reply->data != NULL) {
600 asn1_push_tag(data,ASN1_CONTEXT(2));
601 asn1_write_OctetString(data, reply->data, reply->length);
602 asn1_pop_tag(data);
603 }
604
605 asn1_pop_tag(data);
606 asn1_pop_tag(data);
607
608 ret = data_blob(data->data, data->length);
609 asn1_free(data);
610 return ret;
611}
612
613/*
614 parse a SPNEGO auth packet. This contains the encrypted passwords
615*/
616bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
617 const char *mechOID,
618 DATA_BLOB *auth)
619{
620 ASN1_DATA *data;
621 uint8 negResult;
622
623 if (NT_STATUS_IS_OK(nt_status)) {
624 negResult = SPNEGO_ACCEPT_COMPLETED;
625 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
626 negResult = SPNEGO_ACCEPT_INCOMPLETE;
627 } else {
628 negResult = SPNEGO_REJECT;
629 }
630
631 data = asn1_init(talloc_tos());
632 if (data == NULL) {
633 return false;
634 }
635
636 asn1_load(data, blob);
637 asn1_start_tag(data, ASN1_CONTEXT(1));
638 asn1_start_tag(data, ASN1_SEQUENCE(0));
639 asn1_start_tag(data, ASN1_CONTEXT(0));
640 asn1_check_enumerated(data, negResult);
641 asn1_end_tag(data);
642
643 *auth = data_blob_null;
644
645 if (asn1_tag_remaining(data)) {
646 asn1_start_tag(data,ASN1_CONTEXT(1));
647 asn1_check_OID(data, mechOID);
648 asn1_end_tag(data);
649
650 if (asn1_tag_remaining(data)) {
651 asn1_start_tag(data,ASN1_CONTEXT(2));
652 asn1_read_OctetString(data, talloc_autofree_context(), auth);
653 asn1_end_tag(data);
654 }
655 } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
656 data->has_error = 1;
657 }
658
659 /* Binding against Win2K DC returns a duplicate of the responseToken in
660 * the optional mechListMIC field. This is a bug in Win2K. We ignore
661 * this field if it exists. Win2K8 may return a proper mechListMIC at
662 * which point we need to implement the integrity checking. */
663 if (asn1_tag_remaining(data)) {
664 DATA_BLOB mechList = data_blob_null;
665 asn1_start_tag(data, ASN1_CONTEXT(3));
666 asn1_read_OctetString(data, talloc_autofree_context(), &mechList);
667 asn1_end_tag(data);
668 data_blob_free(&mechList);
669 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
670 "ignoring.\n"));
671 }
672
673 asn1_end_tag(data);
674 asn1_end_tag(data);
675
676 if (data->has_error) {
677 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
678 asn1_free(data);
679 data_blob_free(auth);
680 return False;
681 }
682
683 asn1_free(data);
684 return True;
685}
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