/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- spnego_gen_negTokenInit
- gen_negTokenInit
- spnego_parse_negTokenInit
- gen_negTokenTarg
- parse_negTokenTarg
- spnego_gen_krb5_wrap
- spnego_parse_krb5_wrap
- spnego_gen_negTokenTarg
- spnego_parse_challenge
- spnego_gen_auth
- spnego_parse_auth
- spnego_gen_auth_response
- spnego_parse_auth_response
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
24 /*
25 generate a negTokenInit packet given a GUID, a list of supported
26 OIDs (the mechanisms) and a principal name string
27 */
28 DATA_BLOB spnego_gen_negTokenInit(char guid[16],
/* [<][>][^][v][top][bottom][index][help] */
29 const char *OIDs[],
30 const char *principal)
31 {
32 int i;
33 ASN1_DATA *data;
34 DATA_BLOB ret;
35
36 data = asn1_init(talloc_tos());
37 if (data == NULL) {
38 return data_blob_null;
39 }
40
41 asn1_write(data, guid, 16);
42 asn1_push_tag(data,ASN1_APPLICATION(0));
43 asn1_write_OID(data,OID_SPNEGO);
44 asn1_push_tag(data,ASN1_CONTEXT(0));
45 asn1_push_tag(data,ASN1_SEQUENCE(0));
46
47 asn1_push_tag(data,ASN1_CONTEXT(0));
48 asn1_push_tag(data,ASN1_SEQUENCE(0));
49 for (i=0; OIDs[i]; i++) {
50 asn1_write_OID(data,OIDs[i]);
51 }
52 asn1_pop_tag(data);
53 asn1_pop_tag(data);
54
55 asn1_push_tag(data, ASN1_CONTEXT(3));
56 asn1_push_tag(data, ASN1_SEQUENCE(0));
57 asn1_push_tag(data, ASN1_CONTEXT(0));
58 asn1_write_GeneralString(data,principal);
59 asn1_pop_tag(data);
60 asn1_pop_tag(data);
61 asn1_pop_tag(data);
62
63 asn1_pop_tag(data);
64 asn1_pop_tag(data);
65
66 asn1_pop_tag(data);
67
68 if (data->has_error) {
69 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
70 }
71
72 ret = data_blob(data->data, data->length);
73 asn1_free(data);
74
75 return ret;
76 }
77
78 /*
79 Generate a negTokenInit as used by the client side ... It has a mechType
80 (OID), and a mechToken (a security blob) ...
81
82 Really, we need to break out the NTLMSSP stuff as well, because it could be
83 raw in the packets!
84 */
85 DATA_BLOB gen_negTokenInit(const char *OID, DATA_BLOB blob)
/* [<][>][^][v][top][bottom][index][help] */
86 {
87 ASN1_DATA *data;
88 DATA_BLOB ret;
89
90 data = asn1_init(talloc_tos());
91 if (data == NULL) {
92 return data_blob_null;
93 }
94
95 asn1_push_tag(data, ASN1_APPLICATION(0));
96 asn1_write_OID(data,OID_SPNEGO);
97 asn1_push_tag(data, ASN1_CONTEXT(0));
98 asn1_push_tag(data, ASN1_SEQUENCE(0));
99
100 asn1_push_tag(data, ASN1_CONTEXT(0));
101 asn1_push_tag(data, ASN1_SEQUENCE(0));
102 asn1_write_OID(data, OID);
103 asn1_pop_tag(data);
104 asn1_pop_tag(data);
105
106 asn1_push_tag(data, ASN1_CONTEXT(2));
107 asn1_write_OctetString(data,blob.data,blob.length);
108 asn1_pop_tag(data);
109
110 asn1_pop_tag(data);
111 asn1_pop_tag(data);
112
113 asn1_pop_tag(data);
114
115 if (data->has_error) {
116 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
117 }
118
119 ret = data_blob(data->data, data->length);
120 asn1_free(data);
121
122 return ret;
123 }
124
125 /*
126 parse a negTokenInit packet giving a GUID, a list of supported
127 OIDs (the mechanisms) and a principal name string
128 */
129 bool spnego_parse_negTokenInit(DATA_BLOB blob,
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130 char *OIDs[ASN1_MAX_OIDS],
131 char **principal)
132 {
133 int i;
134 bool ret;
135 ASN1_DATA *data;
136
137 data = asn1_init(talloc_tos());
138 if (data == NULL) {
139 return false;
140 }
141
142 asn1_load(data, blob);
143
144 asn1_start_tag(data,ASN1_APPLICATION(0));
145
146 asn1_check_OID(data,OID_SPNEGO);
147 asn1_start_tag(data,ASN1_CONTEXT(0));
148 asn1_start_tag(data,ASN1_SEQUENCE(0));
149
150 asn1_start_tag(data,ASN1_CONTEXT(0));
151 asn1_start_tag(data,ASN1_SEQUENCE(0));
152 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
153 const char *oid_str = NULL;
154 asn1_read_OID(data,NULL,&oid_str);
155 OIDs[i] = CONST_DISCARD(char *, oid_str);
156 }
157 OIDs[i] = NULL;
158 asn1_end_tag(data);
159 asn1_end_tag(data);
160
161 *principal = NULL;
162 if (asn1_tag_remaining(data) > 0) {
163 asn1_start_tag(data, ASN1_CONTEXT(3));
164 asn1_start_tag(data, ASN1_SEQUENCE(0));
165 asn1_start_tag(data, ASN1_CONTEXT(0));
166 asn1_read_GeneralString(data,NULL,principal);
167 asn1_end_tag(data);
168 asn1_end_tag(data);
169 asn1_end_tag(data);
170 }
171
172 asn1_end_tag(data);
173 asn1_end_tag(data);
174
175 asn1_end_tag(data);
176
177 ret = !data->has_error;
178 if (data->has_error) {
179 int j;
180 TALLOC_FREE(*principal);
181 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
182 TALLOC_FREE(OIDs[j]);
183 }
184 }
185
186 asn1_free(data);
187 return ret;
188 }
189
190 /*
191 generate a negTokenTarg packet given a list of OIDs and a security blob
192 */
193 DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob)
/* [<][>][^][v][top][bottom][index][help] */
194 {
195 int i;
196 ASN1_DATA *data;
197 DATA_BLOB ret;
198
199 data = asn1_init(talloc_tos());
200 if (data == NULL) {
201 return data_blob_null;
202 }
203
204 asn1_push_tag(data, ASN1_APPLICATION(0));
205 asn1_write_OID(data,OID_SPNEGO);
206 asn1_push_tag(data, ASN1_CONTEXT(0));
207 asn1_push_tag(data, ASN1_SEQUENCE(0));
208
209 asn1_push_tag(data, ASN1_CONTEXT(0));
210 asn1_push_tag(data, ASN1_SEQUENCE(0));
211 for (i=0; OIDs[i]; i++) {
212 asn1_write_OID(data,OIDs[i]);
213 }
214 asn1_pop_tag(data);
215 asn1_pop_tag(data);
216
217 asn1_push_tag(data, ASN1_CONTEXT(2));
218 asn1_write_OctetString(data,blob.data,blob.length);
219 asn1_pop_tag(data);
220
221 asn1_pop_tag(data);
222 asn1_pop_tag(data);
223
224 asn1_pop_tag(data);
225
226 if (data->has_error) {
227 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs));
228 }
229
230 ret = data_blob(data->data, data->length);
231 asn1_free(data);
232
233 return ret;
234 }
235
236 /*
237 parse a negTokenTarg packet giving a list of OIDs and a security blob
238 */
239 bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob)
/* [<][>][^][v][top][bottom][index][help] */
240 {
241 int i;
242 ASN1_DATA *data;
243
244 data = asn1_init(talloc_tos());
245 if (data == NULL) {
246 return false;
247 }
248
249 asn1_load(data, blob);
250 asn1_start_tag(data, ASN1_APPLICATION(0));
251 asn1_check_OID(data,OID_SPNEGO);
252 asn1_start_tag(data, ASN1_CONTEXT(0));
253 asn1_start_tag(data, ASN1_SEQUENCE(0));
254
255 asn1_start_tag(data, ASN1_CONTEXT(0));
256 asn1_start_tag(data, ASN1_SEQUENCE(0));
257 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
258 const char *oid_str = NULL;
259 asn1_read_OID(data,NULL,&oid_str);
260 OIDs[i] = CONST_DISCARD(char *, oid_str);
261 }
262 OIDs[i] = NULL;
263 asn1_end_tag(data);
264 asn1_end_tag(data);
265
266 /* Skip any optional req_flags that are sent per RFC 4178 */
267 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
268 uint8 flags;
269
270 asn1_start_tag(data, ASN1_CONTEXT(1));
271 asn1_start_tag(data, ASN1_BITFIELD);
272 while (asn1_tag_remaining(data) > 0)
273 asn1_read_uint8(data, &flags);
274 asn1_end_tag(data);
275 asn1_end_tag(data);
276 }
277
278 asn1_start_tag(data, ASN1_CONTEXT(2));
279 asn1_read_OctetString(data,NULL,secblob);
280 asn1_end_tag(data);
281
282 asn1_end_tag(data);
283 asn1_end_tag(data);
284
285 asn1_end_tag(data);
286
287 if (data->has_error) {
288 int j;
289 data_blob_free(secblob);
290 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
291 TALLOC_FREE(OIDs[j]);
292 }
293 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs));
294 asn1_free(data);
295 return False;
296 }
297
298 asn1_free(data);
299 return True;
300 }
301
302 /*
303 generate a krb5 GSS-API wrapper packet given a ticket
304 */
305 DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2])
/* [<][>][^][v][top][bottom][index][help] */
306 {
307 ASN1_DATA *data;
308 DATA_BLOB ret;
309
310 data = asn1_init(talloc_tos());
311 if (data == NULL) {
312 return data_blob_null;
313 }
314
315 asn1_push_tag(data, ASN1_APPLICATION(0));
316 asn1_write_OID(data, OID_KERBEROS5);
317
318 asn1_write(data, tok_id, 2);
319 asn1_write(data, ticket.data, ticket.length);
320 asn1_pop_tag(data);
321
322 if (data->has_error) {
323 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
324 }
325
326 ret = data_blob(data->data, data->length);
327 asn1_free(data);
328
329 return ret;
330 }
331
332 /*
333 parse a krb5 GSS-API wrapper packet giving a ticket
334 */
335 bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
/* [<][>][^][v][top][bottom][index][help] */
336 {
337 bool ret;
338 ASN1_DATA *data;
339 int data_remaining;
340
341 data = asn1_init(talloc_tos());
342 if (data == NULL) {
343 return false;
344 }
345
346 asn1_load(data, blob);
347 asn1_start_tag(data, ASN1_APPLICATION(0));
348 asn1_check_OID(data, OID_KERBEROS5);
349
350 data_remaining = asn1_tag_remaining(data);
351
352 if (data_remaining < 3) {
353 data->has_error = True;
354 } else {
355 asn1_read(data, tok_id, 2);
356 data_remaining -= 2;
357 *ticket = data_blob(NULL, data_remaining);
358 asn1_read(data, ticket->data, ticket->length);
359 }
360
361 asn1_end_tag(data);
362
363 ret = !data->has_error;
364
365 if (data->has_error) {
366 data_blob_free(ticket);
367 }
368
369 asn1_free(data);
370
371 return ret;
372 }
373
374
375 /*
376 generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY
377 kerberos session setup
378 */
379 int spnego_gen_negTokenTarg(const char *principal, int time_offset,
/* [<][>][^][v][top][bottom][index][help] */
380 DATA_BLOB *targ,
381 DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
382 time_t *expire_time)
383 {
384 int retval;
385 DATA_BLOB tkt, tkt_wrapped;
386 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
387
388 /* get a kerberos ticket for the service and extract the session key */
389 retval = cli_krb5_get_ticket(principal, time_offset,
390 &tkt, session_key_krb5, extra_ap_opts, NULL,
391 expire_time);
392
393 if (retval)
394 return retval;
395
396 /* wrap that up in a nice GSS-API wrapping */
397 tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
398
399 /* and wrap that in a shiny SPNEGO wrapper */
400 *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
401
402 data_blob_free(&tkt_wrapped);
403 data_blob_free(&tkt);
404
405 return retval;
406 }
407
408
409 /*
410 parse a spnego NTLMSSP challenge packet giving two security blobs
411 */
412 bool spnego_parse_challenge(const DATA_BLOB blob,
/* [<][>][^][v][top][bottom][index][help] */
413 DATA_BLOB *chal1, DATA_BLOB *chal2)
414 {
415 bool ret;
416 ASN1_DATA *data;
417
418 ZERO_STRUCTP(chal1);
419 ZERO_STRUCTP(chal2);
420
421 data = asn1_init(talloc_tos());
422 if (data == NULL) {
423 return false;
424 }
425
426 asn1_load(data, blob);
427 asn1_start_tag(data,ASN1_CONTEXT(1));
428 asn1_start_tag(data,ASN1_SEQUENCE(0));
429
430 asn1_start_tag(data,ASN1_CONTEXT(0));
431 asn1_check_enumerated(data,1);
432 asn1_end_tag(data);
433
434 asn1_start_tag(data,ASN1_CONTEXT(1));
435 asn1_check_OID(data, OID_NTLMSSP);
436 asn1_end_tag(data);
437
438 asn1_start_tag(data,ASN1_CONTEXT(2));
439 asn1_read_OctetString(data, NULL, chal1);
440 asn1_end_tag(data);
441
442 /* the second challenge is optional (XP doesn't send it) */
443 if (asn1_tag_remaining(data)) {
444 asn1_start_tag(data,ASN1_CONTEXT(3));
445 asn1_read_OctetString(data, NULL, chal2);
446 asn1_end_tag(data);
447 }
448
449 asn1_end_tag(data);
450 asn1_end_tag(data);
451
452 ret = !data->has_error;
453
454 if (data->has_error) {
455 data_blob_free(chal1);
456 data_blob_free(chal2);
457 }
458
459 asn1_free(data);
460 return ret;
461 }
462
463
464 /*
465 generate a SPNEGO auth packet. This will contain the encrypted passwords
466 */
467 DATA_BLOB spnego_gen_auth(DATA_BLOB blob)
/* [<][>][^][v][top][bottom][index][help] */
468 {
469 ASN1_DATA *data;
470 DATA_BLOB ret;
471
472 data = asn1_init(talloc_tos());
473 if (data == NULL) {
474 return data_blob_null;
475 }
476
477 asn1_push_tag(data, ASN1_CONTEXT(1));
478 asn1_push_tag(data, ASN1_SEQUENCE(0));
479 asn1_push_tag(data, ASN1_CONTEXT(2));
480 asn1_write_OctetString(data,blob.data,blob.length);
481 asn1_pop_tag(data);
482 asn1_pop_tag(data);
483 asn1_pop_tag(data);
484
485 ret = data_blob(data->data, data->length);
486
487 asn1_free(data);
488
489 return ret;
490 }
491
492 /*
493 parse a SPNEGO auth packet. This contains the encrypted passwords
494 */
495 bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
/* [<][>][^][v][top][bottom][index][help] */
496 {
497 SPNEGO_DATA token;
498 ssize_t len;
499
500 len = read_spnego_data(talloc_tos(), blob, &token);
501 if (len == -1) {
502 DEBUG(3,("spnego_parse_auth: read_spnego_data failed\n"));
503 return false;
504 }
505
506 if (token.type != SPNEGO_NEG_TOKEN_TARG) {
507 DEBUG(3,("spnego_parse_auth: wrong token type: %d\n",
508 token.type));
509 free_spnego_data(&token);
510 return false;
511 }
512
513 *auth = data_blob_talloc(talloc_tos(),
514 token.negTokenTarg.responseToken.data,
515 token.negTokenTarg.responseToken.length);
516 free_spnego_data(&token);
517
518 return true;
519 }
520
521 /*
522 generate a minimal SPNEGO response packet. Doesn't contain much.
523 */
524 DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
/* [<][>][^][v][top][bottom][index][help] */
525 const char *mechOID)
526 {
527 ASN1_DATA *data;
528 DATA_BLOB ret;
529 uint8 negResult;
530
531 if (NT_STATUS_IS_OK(nt_status)) {
532 negResult = SPNEGO_NEG_RESULT_ACCEPT;
533 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
534 negResult = SPNEGO_NEG_RESULT_INCOMPLETE;
535 } else {
536 negResult = SPNEGO_NEG_RESULT_REJECT;
537 }
538
539 data = asn1_init(talloc_tos());
540 if (data == NULL) {
541 return data_blob_null;
542 }
543
544 asn1_push_tag(data, ASN1_CONTEXT(1));
545 asn1_push_tag(data, ASN1_SEQUENCE(0));
546 asn1_push_tag(data, ASN1_CONTEXT(0));
547 asn1_write_enumerated(data, negResult);
548 asn1_pop_tag(data);
549
550 if (mechOID) {
551 asn1_push_tag(data,ASN1_CONTEXT(1));
552 asn1_write_OID(data, mechOID);
553 asn1_pop_tag(data);
554 }
555
556 if (reply && reply->data != NULL) {
557 asn1_push_tag(data,ASN1_CONTEXT(2));
558 asn1_write_OctetString(data, reply->data, reply->length);
559 asn1_pop_tag(data);
560 }
561
562 asn1_pop_tag(data);
563 asn1_pop_tag(data);
564
565 ret = data_blob(data->data, data->length);
566 asn1_free(data);
567 return ret;
568 }
569
570 /*
571 parse a SPNEGO auth packet. This contains the encrypted passwords
572 */
573 bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
/* [<][>][^][v][top][bottom][index][help] */
574 const char *mechOID,
575 DATA_BLOB *auth)
576 {
577 ASN1_DATA *data;
578 uint8 negResult;
579
580 if (NT_STATUS_IS_OK(nt_status)) {
581 negResult = SPNEGO_NEG_RESULT_ACCEPT;
582 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
583 negResult = SPNEGO_NEG_RESULT_INCOMPLETE;
584 } else {
585 negResult = SPNEGO_NEG_RESULT_REJECT;
586 }
587
588 data = asn1_init(talloc_tos());
589 if (data == NULL) {
590 return false;
591 }
592
593 asn1_load(data, blob);
594 asn1_start_tag(data, ASN1_CONTEXT(1));
595 asn1_start_tag(data, ASN1_SEQUENCE(0));
596 asn1_start_tag(data, ASN1_CONTEXT(0));
597 asn1_check_enumerated(data, negResult);
598 asn1_end_tag(data);
599
600 *auth = data_blob_null;
601
602 if (asn1_tag_remaining(data)) {
603 asn1_start_tag(data,ASN1_CONTEXT(1));
604 asn1_check_OID(data, mechOID);
605 asn1_end_tag(data);
606
607 if (asn1_tag_remaining(data)) {
608 asn1_start_tag(data,ASN1_CONTEXT(2));
609 asn1_read_OctetString(data, NULL, auth);
610 asn1_end_tag(data);
611 }
612 } else if (negResult == SPNEGO_NEG_RESULT_INCOMPLETE) {
613 data->has_error = 1;
614 }
615
616 /* Binding against Win2K DC returns a duplicate of the responseToken in
617 * the optional mechListMIC field. This is a bug in Win2K. We ignore
618 * this field if it exists. Win2K8 may return a proper mechListMIC at
619 * which point we need to implement the integrity checking. */
620 if (asn1_tag_remaining(data)) {
621 DATA_BLOB mechList = data_blob_null;
622 asn1_start_tag(data, ASN1_CONTEXT(3));
623 asn1_read_OctetString(data, NULL, &mechList);
624 asn1_end_tag(data);
625 data_blob_free(&mechList);
626 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
627 "ignoring.\n"));
628 }
629
630 asn1_end_tag(data);
631 asn1_end_tag(data);
632
633 if (data->has_error) {
634 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
635 asn1_free(data);
636 data_blob_free(auth);
637 return False;
638 }
639
640 asn1_free(data);
641 return True;
642 }