source: branches/samba-3.5.x/source3/libsmb/clispnego.c@ 736

Last change on this file since 736 was 736, checked in by Silvan Scherrer, 13 years ago

Samba Server 3.5: update branche to 3.5.16
File size: 16.5 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 if (data->has_error) {
165 break;
166 }
167 OIDs[i] = CONST_DISCARD(char *, oid_str);
168 }
169 OIDs[i] = NULL;
170 asn1_end_tag(data);
171 asn1_end_tag(data);
172
173 *principal = NULL;
174
175 /*
176 Win7 + Live Sign-in Assistant attaches a mechToken
177 ASN1_CONTEXT(2) to the negTokenInit packet
178 which breaks our negotiation if we just assume
179 the next tag is ASN1_CONTEXT(3).
180 */
181
182 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
183 uint8 flags;
184
185 /* reqFlags [1] ContextFlags OPTIONAL */
186 asn1_start_tag(data, ASN1_CONTEXT(1));
187 asn1_start_tag(data, ASN1_BIT_STRING);
188 while (asn1_tag_remaining(data) > 0) {
189 asn1_read_uint8(data, &flags);
190 }
191 asn1_end_tag(data);
192 asn1_end_tag(data);
193 }
194
195 if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
196 /* mechToken [2] OCTET STRING OPTIONAL */
197 DATA_BLOB token;
198 asn1_start_tag(data, ASN1_CONTEXT(2));
199 asn1_read_OctetString(data, talloc_autofree_context(),
200 &token);
201 asn1_end_tag(data);
202 /* Throw away the token - not used. */
203 data_blob_free(&token);
204 }
205
206 if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
207 /* mechListMIC [3] OCTET STRING OPTIONAL */
208 asn1_start_tag(data, ASN1_CONTEXT(3));
209 asn1_start_tag(data, ASN1_SEQUENCE(0));
210 asn1_start_tag(data, ASN1_CONTEXT(0));
211 asn1_read_GeneralString(data,talloc_autofree_context(),
212 principal);
213 asn1_end_tag(data);
214 asn1_end_tag(data);
215 asn1_end_tag(data);
216 }
217
218 asn1_end_tag(data);
219 asn1_end_tag(data);
220
221 asn1_end_tag(data);
222
223 ret = !data->has_error;
224 if (data->has_error) {
225 int j;
226 TALLOC_FREE(*principal);
227 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
228 TALLOC_FREE(OIDs[j]);
229 }
230 }
231
232 asn1_free(data);
233 return ret;
234}
235
236/*
237 generate a negTokenTarg packet given a list of OIDs and a security blob
238*/
239DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob)
240{
241 int i;
242 ASN1_DATA *data;
243 DATA_BLOB ret;
244
245 data = asn1_init(talloc_tos());
246 if (data == NULL) {
247 return data_blob_null;
248 }
249
250 asn1_push_tag(data, ASN1_APPLICATION(0));
251 asn1_write_OID(data,OID_SPNEGO);
252 asn1_push_tag(data, ASN1_CONTEXT(0));
253 asn1_push_tag(data, ASN1_SEQUENCE(0));
254
255 asn1_push_tag(data, ASN1_CONTEXT(0));
256 asn1_push_tag(data, ASN1_SEQUENCE(0));
257 for (i=0; OIDs[i]; i++) {
258 asn1_write_OID(data,OIDs[i]);
259 }
260 asn1_pop_tag(data);
261 asn1_pop_tag(data);
262
263 asn1_push_tag(data, ASN1_CONTEXT(2));
264 asn1_write_OctetString(data,blob.data,blob.length);
265 asn1_pop_tag(data);
266
267 asn1_pop_tag(data);
268 asn1_pop_tag(data);
269
270 asn1_pop_tag(data);
271
272 if (data->has_error) {
273 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs));
274 }
275
276 ret = data_blob(data->data, data->length);
277 asn1_free(data);
278
279 return ret;
280}
281
282/*
283 parse a negTokenTarg packet giving a list of OIDs and a security blob
284*/
285bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob)
286{
287 int i;
288 ASN1_DATA *data;
289
290 data = asn1_init(talloc_tos());
291 if (data == NULL) {
292 return false;
293 }
294
295 asn1_load(data, blob);
296 asn1_start_tag(data, ASN1_APPLICATION(0));
297 asn1_check_OID(data,OID_SPNEGO);
298 asn1_start_tag(data, ASN1_CONTEXT(0));
299 asn1_start_tag(data, ASN1_SEQUENCE(0));
300
301 asn1_start_tag(data, ASN1_CONTEXT(0));
302 asn1_start_tag(data, ASN1_SEQUENCE(0));
303 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
304 const char *oid_str = NULL;
305 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
306 OIDs[i] = CONST_DISCARD(char *, oid_str);
307 }
308 OIDs[i] = NULL;
309 asn1_end_tag(data);
310 asn1_end_tag(data);
311
312 /* Skip any optional req_flags that are sent per RFC 4178 */
313 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
314 uint8 flags;
315
316 asn1_start_tag(data, ASN1_CONTEXT(1));
317 asn1_start_tag(data, ASN1_BIT_STRING);
318 while (asn1_tag_remaining(data) > 0)
319 asn1_read_uint8(data, &flags);
320 asn1_end_tag(data);
321 asn1_end_tag(data);
322 }
323
324 asn1_start_tag(data, ASN1_CONTEXT(2));
325 asn1_read_OctetString(data,talloc_autofree_context(),secblob);
326 asn1_end_tag(data);
327
328 asn1_end_tag(data);
329 asn1_end_tag(data);
330
331 asn1_end_tag(data);
332
333 if (data->has_error) {
334 int j;
335 data_blob_free(secblob);
336 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
337 TALLOC_FREE(OIDs[j]);
338 }
339 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs));
340 asn1_free(data);
341 return False;
342 }
343
344 asn1_free(data);
345 return True;
346}
347
348/*
349 generate a krb5 GSS-API wrapper packet given a ticket
350*/
351DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2])
352{
353 ASN1_DATA *data;
354 DATA_BLOB ret;
355
356 data = asn1_init(talloc_tos());
357 if (data == NULL) {
358 return data_blob_null;
359 }
360
361 asn1_push_tag(data, ASN1_APPLICATION(0));
362 asn1_write_OID(data, OID_KERBEROS5);
363
364 asn1_write(data, tok_id, 2);
365 asn1_write(data, ticket.data, ticket.length);
366 asn1_pop_tag(data);
367
368 if (data->has_error) {
369 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
370 }
371
372 ret = data_blob(data->data, data->length);
373 asn1_free(data);
374
375 return ret;
376}
377
378/*
379 parse a krb5 GSS-API wrapper packet giving a ticket
380*/
381bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
382{
383 bool ret;
384 ASN1_DATA *data;
385 int data_remaining;
386
387 data = asn1_init(talloc_tos());
388 if (data == NULL) {
389 return false;
390 }
391
392 asn1_load(data, blob);
393 asn1_start_tag(data, ASN1_APPLICATION(0));
394 asn1_check_OID(data, OID_KERBEROS5);
395
396 data_remaining = asn1_tag_remaining(data);
397
398 if (data_remaining < 3) {
399 data->has_error = True;
400 } else {
401 asn1_read(data, tok_id, 2);
402 data_remaining -= 2;
403 *ticket = data_blob(NULL, data_remaining);
404 asn1_read(data, ticket->data, ticket->length);
405 }
406
407 asn1_end_tag(data);
408
409 ret = !data->has_error;
410
411 if (data->has_error) {
412 data_blob_free(ticket);
413 }
414
415 asn1_free(data);
416
417 return ret;
418}
419
420
421/*
422 generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY
423 kerberos session setup
424*/
425int spnego_gen_negTokenTarg(const char *principal, int time_offset,
426 DATA_BLOB *targ,
427 DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
428 time_t *expire_time)
429{
430 int retval;
431 DATA_BLOB tkt, tkt_wrapped;
432 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
433
434 /* get a kerberos ticket for the service and extract the session key */
435 retval = cli_krb5_get_ticket(principal, time_offset,
436 &tkt, session_key_krb5, extra_ap_opts, NULL,
437 expire_time, NULL);
438
439 if (retval)
440 return retval;
441
442 /* wrap that up in a nice GSS-API wrapping */
443 tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
444
445 /* and wrap that in a shiny SPNEGO wrapper */
446 *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
447
448 data_blob_free(&tkt_wrapped);
449 data_blob_free(&tkt);
450
451 return retval;
452}
453
454
455/*
456 parse a spnego NTLMSSP challenge packet giving two security blobs
457*/
458bool spnego_parse_challenge(const DATA_BLOB blob,
459 DATA_BLOB *chal1, DATA_BLOB *chal2)
460{
461 bool ret;
462 ASN1_DATA *data;
463
464 ZERO_STRUCTP(chal1);
465 ZERO_STRUCTP(chal2);
466
467 data = asn1_init(talloc_tos());
468 if (data == NULL) {
469 return false;
470 }
471
472 asn1_load(data, blob);
473 asn1_start_tag(data,ASN1_CONTEXT(1));
474 asn1_start_tag(data,ASN1_SEQUENCE(0));
475
476 asn1_start_tag(data,ASN1_CONTEXT(0));
477 asn1_check_enumerated(data,1);
478 asn1_end_tag(data);
479
480 asn1_start_tag(data,ASN1_CONTEXT(1));
481 asn1_check_OID(data, OID_NTLMSSP);
482 asn1_end_tag(data);
483
484 asn1_start_tag(data,ASN1_CONTEXT(2));
485 asn1_read_OctetString(data, talloc_autofree_context(), chal1);
486 asn1_end_tag(data);
487
488 /* the second challenge is optional (XP doesn't send it) */
489 if (asn1_tag_remaining(data)) {
490 asn1_start_tag(data,ASN1_CONTEXT(3));
491 asn1_read_OctetString(data, talloc_autofree_context(), chal2);
492 asn1_end_tag(data);
493 }
494
495 asn1_end_tag(data);
496 asn1_end_tag(data);
497
498 ret = !data->has_error;
499
500 if (data->has_error) {
501 data_blob_free(chal1);
502 data_blob_free(chal2);
503 }
504
505 asn1_free(data);
506 return ret;
507}
508
509
510/*
511 generate a SPNEGO auth packet. This will contain the encrypted passwords
512*/
513DATA_BLOB spnego_gen_auth(DATA_BLOB blob)
514{
515 ASN1_DATA *data;
516 DATA_BLOB ret;
517
518 data = asn1_init(talloc_tos());
519 if (data == NULL) {
520 return data_blob_null;
521 }
522
523 asn1_push_tag(data, ASN1_CONTEXT(1));
524 asn1_push_tag(data, ASN1_SEQUENCE(0));
525 asn1_push_tag(data, ASN1_CONTEXT(2));
526 asn1_write_OctetString(data,blob.data,blob.length);
527 asn1_pop_tag(data);
528 asn1_pop_tag(data);
529 asn1_pop_tag(data);
530
531 ret = data_blob(data->data, data->length);
532
533 asn1_free(data);
534
535 return ret;
536}
537
538/*
539 parse a SPNEGO auth packet. This contains the encrypted passwords
540*/
541bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
542{
543 ssize_t len;
544 struct spnego_data token;
545
546 len = spnego_read_data(talloc_tos(), blob, &token);
547 if (len == -1) {
548 DEBUG(3,("spnego_parse_auth: spnego_read_data failed\n"));
549 return false;
550 }
551
552 if (token.type != SPNEGO_NEG_TOKEN_TARG) {
553 DEBUG(3,("spnego_parse_auth: wrong token type: %d\n",
554 token.type));
555 spnego_free_data(&token);
556 return false;
557 }
558
559 *auth = data_blob_talloc(talloc_tos(),
560 token.negTokenTarg.responseToken.data,
561 token.negTokenTarg.responseToken.length);
562 spnego_free_data(&token);
563
564 return true;
565}
566
567/*
568 generate a minimal SPNEGO response packet. Doesn't contain much.
569*/
570DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
571 const char *mechOID)
572{
573 ASN1_DATA *data;
574 DATA_BLOB ret;
575 uint8 negResult;
576
577 if (NT_STATUS_IS_OK(nt_status)) {
578 negResult = SPNEGO_ACCEPT_COMPLETED;
579 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
580 negResult = SPNEGO_ACCEPT_INCOMPLETE;
581 } else {
582 negResult = SPNEGO_REJECT;
583 }
584
585 data = asn1_init(talloc_tos());
586 if (data == NULL) {
587 return data_blob_null;
588 }
589
590 asn1_push_tag(data, ASN1_CONTEXT(1));
591 asn1_push_tag(data, ASN1_SEQUENCE(0));
592 asn1_push_tag(data, ASN1_CONTEXT(0));
593 asn1_write_enumerated(data, negResult);
594 asn1_pop_tag(data);
595
596 if (mechOID) {
597 asn1_push_tag(data,ASN1_CONTEXT(1));
598 asn1_write_OID(data, mechOID);
599 asn1_pop_tag(data);
600 }
601
602 if (reply && reply->data != NULL) {
603 asn1_push_tag(data,ASN1_CONTEXT(2));
604 asn1_write_OctetString(data, reply->data, reply->length);
605 asn1_pop_tag(data);
606 }
607
608 asn1_pop_tag(data);
609 asn1_pop_tag(data);
610
611 ret = data_blob(data->data, data->length);
612 asn1_free(data);
613 return ret;
614}
615
616/*
617 parse a SPNEGO auth packet. This contains the encrypted passwords
618*/
619bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
620 const char *mechOID,
621 DATA_BLOB *auth)
622{
623 ASN1_DATA *data;
624 uint8 negResult;
625
626 if (NT_STATUS_IS_OK(nt_status)) {
627 negResult = SPNEGO_ACCEPT_COMPLETED;
628 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
629 negResult = SPNEGO_ACCEPT_INCOMPLETE;
630 } else {
631 negResult = SPNEGO_REJECT;
632 }
633
634 data = asn1_init(talloc_tos());
635 if (data == NULL) {
636 return false;
637 }
638
639 asn1_load(data, blob);
640 asn1_start_tag(data, ASN1_CONTEXT(1));
641 asn1_start_tag(data, ASN1_SEQUENCE(0));
642 asn1_start_tag(data, ASN1_CONTEXT(0));
643 asn1_check_enumerated(data, negResult);
644 asn1_end_tag(data);
645
646 *auth = data_blob_null;
647
648 if (asn1_tag_remaining(data)) {
649 asn1_start_tag(data,ASN1_CONTEXT(1));
650 asn1_check_OID(data, mechOID);
651 asn1_end_tag(data);
652
653 if (asn1_tag_remaining(data)) {
654 asn1_start_tag(data,ASN1_CONTEXT(2));
655 asn1_read_OctetString(data, talloc_autofree_context(), auth);
656 asn1_end_tag(data);
657 }
658 } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
659 data->has_error = 1;
660 }
661
662 /* Binding against Win2K DC returns a duplicate of the responseToken in
663 * the optional mechListMIC field. This is a bug in Win2K. We ignore
664 * this field if it exists. Win2K8 may return a proper mechListMIC at
665 * which point we need to implement the integrity checking. */
666 if (asn1_tag_remaining(data)) {
667 DATA_BLOB mechList = data_blob_null;
668 asn1_start_tag(data, ASN1_CONTEXT(3));
669 asn1_read_OctetString(data, talloc_autofree_context(), &mechList);
670 asn1_end_tag(data);
671 data_blob_free(&mechList);
672 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
673 "ignoring.\n"));
674 }
675
676 asn1_end_tag(data);
677 asn1_end_tag(data);
678
679 if (data->has_error) {
680 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
681 asn1_free(data);
682 data_blob_free(auth);
683 return False;
684 }
685
686 asn1_free(data);
687 return True;
688}
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