1 /* $NetBSD: rd_req.c,v 1.1.1.2 2014/04/24 12:45:51 pettai Exp $ */
2
3
4 /*
5 * Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
6 * (Royal Institute of Technology, Stockholm, Sweden).
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * 3. Neither the name of the Institute nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include "krb5_locl.h"
38
39 static krb5_error_code
decrypt_tkt_enc_part(krb5_context context,krb5_keyblock * key,EncryptedData * enc_part,EncTicketPart * decr_part)40 decrypt_tkt_enc_part (krb5_context context,
41 krb5_keyblock *key,
42 EncryptedData *enc_part,
43 EncTicketPart *decr_part)
44 {
45 krb5_error_code ret;
46 krb5_data plain;
47 size_t len;
48 krb5_crypto crypto;
49
50 ret = krb5_crypto_init(context, key, 0, &crypto);
51 if (ret)
52 return ret;
53 ret = krb5_decrypt_EncryptedData (context,
54 crypto,
55 KRB5_KU_TICKET,
56 enc_part,
57 &plain);
58 krb5_crypto_destroy(context, crypto);
59 if (ret)
60 return ret;
61
62 ret = decode_EncTicketPart(plain.data, plain.length, decr_part, &len);
63 if (ret)
64 krb5_set_error_message(context, ret,
65 N_("Failed to decode encrypted "
66 "ticket part", ""));
67 krb5_data_free (&plain);
68 return ret;
69 }
70
71 static krb5_error_code
decrypt_authenticator(krb5_context context,EncryptionKey * key,EncryptedData * enc_part,Authenticator * authenticator,krb5_key_usage usage)72 decrypt_authenticator (krb5_context context,
73 EncryptionKey *key,
74 EncryptedData *enc_part,
75 Authenticator *authenticator,
76 krb5_key_usage usage)
77 {
78 krb5_error_code ret;
79 krb5_data plain;
80 size_t len;
81 krb5_crypto crypto;
82
83 ret = krb5_crypto_init(context, key, 0, &crypto);
84 if (ret)
85 return ret;
86 ret = krb5_decrypt_EncryptedData (context,
87 crypto,
88 usage /* KRB5_KU_AP_REQ_AUTH */,
89 enc_part,
90 &plain);
91 /* for backwards compatibility, also try the old usage */
92 if (ret && usage == KRB5_KU_TGS_REQ_AUTH)
93 ret = krb5_decrypt_EncryptedData (context,
94 crypto,
95 KRB5_KU_AP_REQ_AUTH,
96 enc_part,
97 &plain);
98 krb5_crypto_destroy(context, crypto);
99 if (ret)
100 return ret;
101
102 ret = decode_Authenticator(plain.data, plain.length,
103 authenticator, &len);
104 krb5_data_free (&plain);
105 return ret;
106 }
107
108 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_decode_ap_req(krb5_context context,const krb5_data * inbuf,krb5_ap_req * ap_req)109 krb5_decode_ap_req(krb5_context context,
110 const krb5_data *inbuf,
111 krb5_ap_req *ap_req)
112 {
113 krb5_error_code ret;
114 size_t len;
115 ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len);
116 if (ret)
117 return ret;
118 if (ap_req->pvno != 5){
119 free_AP_REQ(ap_req);
120 krb5_clear_error_message (context);
121 return KRB5KRB_AP_ERR_BADVERSION;
122 }
123 if (ap_req->msg_type != krb_ap_req){
124 free_AP_REQ(ap_req);
125 krb5_clear_error_message (context);
126 return KRB5KRB_AP_ERR_MSG_TYPE;
127 }
128 if (ap_req->ticket.tkt_vno != 5){
129 free_AP_REQ(ap_req);
130 krb5_clear_error_message (context);
131 return KRB5KRB_AP_ERR_BADVERSION;
132 }
133 return 0;
134 }
135
136 static krb5_error_code
check_transited(krb5_context context,Ticket * ticket,EncTicketPart * enc)137 check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc)
138 {
139 char **realms;
140 unsigned int num_realms, n;
141 krb5_error_code ret;
142
143 /*
144 * Windows 2000 and 2003 uses this inside their TGT so it's normaly
145 * not seen by others, however, samba4 joined with a Windows AD as
146 * a Domain Controller gets exposed to this.
147 */
148 if(enc->transited.tr_type == 0 && enc->transited.contents.length == 0)
149 return 0;
150
151 if(enc->transited.tr_type != DOMAIN_X500_COMPRESS)
152 return KRB5KDC_ERR_TRTYPE_NOSUPP;
153
154 if(enc->transited.contents.length == 0)
155 return 0;
156
157 ret = krb5_domain_x500_decode(context, enc->transited.contents,
158 &realms, &num_realms,
159 enc->crealm,
160 ticket->realm);
161 if(ret)
162 return ret;
163 ret = krb5_check_transited(context, enc->crealm,
164 ticket->realm,
165 realms, num_realms, NULL);
166 for (n = 0; n < num_realms; n++)
167 free(realms[n]);
168 free(realms);
169 return ret;
170 }
171
172 static krb5_error_code
find_etypelist(krb5_context context,krb5_auth_context auth_context,EtypeList * etypes)173 find_etypelist(krb5_context context,
174 krb5_auth_context auth_context,
175 EtypeList *etypes)
176 {
177 krb5_error_code ret;
178 krb5_authdata *ad;
179 krb5_authdata adIfRelevant;
180 unsigned i;
181
182 memset(&adIfRelevant, 0, sizeof(adIfRelevant));
183
184 etypes->len = 0;
185 etypes->val = NULL;
186
187 ad = auth_context->authenticator->authorization_data;
188 if (ad == NULL)
189 return 0;
190
191 for (i = 0; i < ad->len; i++) {
192 if (ad->val[i].ad_type == KRB5_AUTHDATA_IF_RELEVANT) {
193 ret = decode_AD_IF_RELEVANT(ad->val[i].ad_data.data,
194 ad->val[i].ad_data.length,
195 &adIfRelevant,
196 NULL);
197 if (ret)
198 return ret;
199
200 if (adIfRelevant.len == 1 &&
201 adIfRelevant.val[0].ad_type ==
202 KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION) {
203 break;
204 }
205 free_AD_IF_RELEVANT(&adIfRelevant);
206 adIfRelevant.len = 0;
207 }
208 }
209
210 if (adIfRelevant.len == 0)
211 return 0;
212
213 ret = decode_EtypeList(adIfRelevant.val[0].ad_data.data,
214 adIfRelevant.val[0].ad_data.length,
215 etypes,
216 NULL);
217 if (ret)
218 krb5_clear_error_message(context);
219
220 free_AD_IF_RELEVANT(&adIfRelevant);
221
222 return ret;
223 }
224
225 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_decrypt_ticket(krb5_context context,Ticket * ticket,krb5_keyblock * key,EncTicketPart * out,krb5_flags flags)226 krb5_decrypt_ticket(krb5_context context,
227 Ticket *ticket,
228 krb5_keyblock *key,
229 EncTicketPart *out,
230 krb5_flags flags)
231 {
232 EncTicketPart t;
233 krb5_error_code ret;
234 ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
235 if (ret)
236 return ret;
237
238 {
239 krb5_timestamp now;
240 time_t start = t.authtime;
241
242 krb5_timeofday (context, &now);
243 if(t.starttime)
244 start = *t.starttime;
245 if(start - now > context->max_skew
246 || (t.flags.invalid
247 && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
248 free_EncTicketPart(&t);
249 krb5_clear_error_message (context);
250 return KRB5KRB_AP_ERR_TKT_NYV;
251 }
252 if(now - t.endtime > context->max_skew) {
253 free_EncTicketPart(&t);
254 krb5_clear_error_message (context);
255 return KRB5KRB_AP_ERR_TKT_EXPIRED;
256 }
257
258 if(!t.flags.transited_policy_checked) {
259 ret = check_transited(context, ticket, &t);
260 if(ret) {
261 free_EncTicketPart(&t);
262 return ret;
263 }
264 }
265 }
266
267 if(out)
268 *out = t;
269 else
270 free_EncTicketPart(&t);
271 return 0;
272 }
273
274 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_verify_authenticator_checksum(krb5_context context,krb5_auth_context ac,void * data,size_t len)275 krb5_verify_authenticator_checksum(krb5_context context,
276 krb5_auth_context ac,
277 void *data,
278 size_t len)
279 {
280 krb5_error_code ret;
281 krb5_keyblock *key;
282 krb5_authenticator authenticator;
283 krb5_crypto crypto;
284
285 ret = krb5_auth_con_getauthenticator (context,
286 ac,
287 &authenticator);
288 if(ret)
289 return ret;
290 if(authenticator->cksum == NULL) {
291 krb5_free_authenticator(context, &authenticator);
292 return -17;
293 }
294 ret = krb5_auth_con_getkey(context, ac, &key);
295 if(ret) {
296 krb5_free_authenticator(context, &authenticator);
297 return ret;
298 }
299 ret = krb5_crypto_init(context, key, 0, &crypto);
300 if(ret)
301 goto out;
302 ret = krb5_verify_checksum (context,
303 crypto,
304 KRB5_KU_AP_REQ_AUTH_CKSUM,
305 data,
306 len,
307 authenticator->cksum);
308 krb5_crypto_destroy(context, crypto);
309 out:
310 krb5_free_authenticator(context, &authenticator);
311 krb5_free_keyblock(context, key);
312 return ret;
313 }
314
315
316 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_verify_ap_req(krb5_context context,krb5_auth_context * auth_context,krb5_ap_req * ap_req,krb5_const_principal server,krb5_keyblock * keyblock,krb5_flags flags,krb5_flags * ap_req_options,krb5_ticket ** ticket)317 krb5_verify_ap_req(krb5_context context,
318 krb5_auth_context *auth_context,
319 krb5_ap_req *ap_req,
320 krb5_const_principal server,
321 krb5_keyblock *keyblock,
322 krb5_flags flags,
323 krb5_flags *ap_req_options,
324 krb5_ticket **ticket)
325 {
326 return krb5_verify_ap_req2 (context,
327 auth_context,
328 ap_req,
329 server,
330 keyblock,
331 flags,
332 ap_req_options,
333 ticket,
334 KRB5_KU_AP_REQ_AUTH);
335 }
336
337 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_verify_ap_req2(krb5_context context,krb5_auth_context * auth_context,krb5_ap_req * ap_req,krb5_const_principal server,krb5_keyblock * keyblock,krb5_flags flags,krb5_flags * ap_req_options,krb5_ticket ** ticket,krb5_key_usage usage)338 krb5_verify_ap_req2(krb5_context context,
339 krb5_auth_context *auth_context,
340 krb5_ap_req *ap_req,
341 krb5_const_principal server,
342 krb5_keyblock *keyblock,
343 krb5_flags flags,
344 krb5_flags *ap_req_options,
345 krb5_ticket **ticket,
346 krb5_key_usage usage)
347 {
348 krb5_ticket *t;
349 krb5_auth_context ac;
350 krb5_error_code ret;
351 EtypeList etypes;
352
353 if (ticket)
354 *ticket = NULL;
355
356 if (auth_context && *auth_context) {
357 ac = *auth_context;
358 } else {
359 ret = krb5_auth_con_init (context, &ac);
360 if (ret)
361 return ret;
362 }
363
364 t = calloc(1, sizeof(*t));
365 if (t == NULL) {
366 ret = ENOMEM;
367 krb5_clear_error_message (context);
368 goto out;
369 }
370
371 if (ap_req->ap_options.use_session_key && ac->keyblock){
372 ret = krb5_decrypt_ticket(context, &ap_req->ticket,
373 ac->keyblock,
374 &t->ticket,
375 flags);
376 krb5_free_keyblock(context, ac->keyblock);
377 ac->keyblock = NULL;
378 }else
379 ret = krb5_decrypt_ticket(context, &ap_req->ticket,
380 keyblock,
381 &t->ticket,
382 flags);
383
384 if(ret)
385 goto out;
386
387 ret = _krb5_principalname2krb5_principal(context,
388 &t->server,
389 ap_req->ticket.sname,
390 ap_req->ticket.realm);
391 if (ret) goto out;
392 ret = _krb5_principalname2krb5_principal(context,
393 &t->client,
394 t->ticket.cname,
395 t->ticket.crealm);
396 if (ret) goto out;
397
398 ret = decrypt_authenticator (context,
399 &t->ticket.key,
400 &ap_req->authenticator,
401 ac->authenticator,
402 usage);
403 if (ret)
404 goto out;
405
406 {
407 krb5_principal p1, p2;
408 krb5_boolean res;
409
410 _krb5_principalname2krb5_principal(context,
411 &p1,
412 ac->authenticator->cname,
413 ac->authenticator->crealm);
414 _krb5_principalname2krb5_principal(context,
415 &p2,
416 t->ticket.cname,
417 t->ticket.crealm);
418 res = krb5_principal_compare (context, p1, p2);
419 krb5_free_principal (context, p1);
420 krb5_free_principal (context, p2);
421 if (!res) {
422 ret = KRB5KRB_AP_ERR_BADMATCH;
423 krb5_clear_error_message (context);
424 goto out;
425 }
426 }
427
428 /* check addresses */
429
430 if (t->ticket.caddr
431 && ac->remote_address
432 && !krb5_address_search (context,
433 ac->remote_address,
434 t->ticket.caddr)) {
435 ret = KRB5KRB_AP_ERR_BADADDR;
436 krb5_clear_error_message (context);
437 goto out;
438 }
439
440 /* check timestamp in authenticator */
441 {
442 krb5_timestamp now;
443
444 krb5_timeofday (context, &now);
445
446 if (abs(ac->authenticator->ctime - now) > context->max_skew) {
447 ret = KRB5KRB_AP_ERR_SKEW;
448 krb5_clear_error_message (context);
449 goto out;
450 }
451 }
452
453 if (ac->authenticator->seq_number)
454 krb5_auth_con_setremoteseqnumber(context, ac,
455 *ac->authenticator->seq_number);
456
457 /* XXX - Xor sequence numbers */
458
459 if (ac->authenticator->subkey) {
460 ret = krb5_auth_con_setremotesubkey(context, ac,
461 ac->authenticator->subkey);
462 if (ret)
463 goto out;
464 }
465
466 ret = find_etypelist(context, ac, &etypes);
467 if (ret)
468 goto out;
469
470 ac->keytype = ETYPE_NULL;
471
472 if (etypes.val) {
473 size_t i;
474
475 for (i = 0; i < etypes.len; i++) {
476 if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
477 ac->keytype = etypes.val[i];
478 break;
479 }
480 }
481 }
482
483 /* save key */
484 ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
485 if (ret) goto out;
486
487 if (ap_req_options) {
488 *ap_req_options = 0;
489 if (ac->keytype != ETYPE_NULL)
490 *ap_req_options |= AP_OPTS_USE_SUBKEY;
491 if (ap_req->ap_options.use_session_key)
492 *ap_req_options |= AP_OPTS_USE_SESSION_KEY;
493 if (ap_req->ap_options.mutual_required)
494 *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
495 }
496
497 if(ticket)
498 *ticket = t;
499 else
500 krb5_free_ticket (context, t);
501 if (auth_context) {
502 if (*auth_context == NULL)
503 *auth_context = ac;
504 } else
505 krb5_auth_con_free (context, ac);
506 free_EtypeList(&etypes);
507 return 0;
508 out:
509 if (t)
510 krb5_free_ticket (context, t);
511 if (auth_context == NULL || *auth_context == NULL)
512 krb5_auth_con_free (context, ac);
513 return ret;
514 }
515
516 /*
517 *
518 */
519
520 struct krb5_rd_req_in_ctx_data {
521 krb5_keytab keytab;
522 krb5_keyblock *keyblock;
523 krb5_boolean check_pac;
524 };
525
526 struct krb5_rd_req_out_ctx_data {
527 krb5_keyblock *keyblock;
528 krb5_flags ap_req_options;
529 krb5_ticket *ticket;
530 krb5_principal server;
531 };
532
533 /**
534 * Allocate a krb5_rd_req_in_ctx as an input parameter to
535 * krb5_rd_req_ctx(). The caller should free the context with
536 * krb5_rd_req_in_ctx_free() when done with the context.
537 *
538 * @param context Keberos 5 context.
539 * @param ctx in ctx to krb5_rd_req_ctx().
540 *
541 * @return Kerberos 5 error code, see krb5_get_error_message().
542 *
543 * @ingroup krb5_auth
544 */
545
546 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_in_ctx_alloc(krb5_context context,krb5_rd_req_in_ctx * ctx)547 krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx)
548 {
549 *ctx = calloc(1, sizeof(**ctx));
550 if (*ctx == NULL) {
551 krb5_set_error_message(context, ENOMEM,
552 N_("malloc: out of memory", ""));
553 return ENOMEM;
554 }
555 (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0;
556 return 0;
557 }
558
559 /**
560 * Set the keytab that krb5_rd_req_ctx() will use.
561 *
562 * @param context Keberos 5 context.
563 * @param in in ctx to krb5_rd_req_ctx().
564 * @param keytab keytab that krb5_rd_req_ctx() will use, only copy the
565 * pointer, so the caller must free they keytab after
566 * krb5_rd_req_in_ctx_free() is called.
567 *
568 * @return Kerberos 5 error code, see krb5_get_error_message().
569 *
570 * @ingroup krb5_auth
571 */
572
573 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_in_set_keytab(krb5_context context,krb5_rd_req_in_ctx in,krb5_keytab keytab)574 krb5_rd_req_in_set_keytab(krb5_context context,
575 krb5_rd_req_in_ctx in,
576 krb5_keytab keytab)
577 {
578 in->keytab = keytab;
579 return 0;
580 }
581
582 /**
583 * Set if krb5_rq_red() is going to check the Windows PAC or not
584 *
585 * @param context Keberos 5 context.
586 * @param in krb5_rd_req_in_ctx to check the option on.
587 * @param flag flag to select if to check the pac (TRUE) or not (FALSE).
588 *
589 * @return Kerberos 5 error code, see krb5_get_error_message().
590 *
591 * @ingroup krb5_auth
592 */
593
594 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_in_set_pac_check(krb5_context context,krb5_rd_req_in_ctx in,krb5_boolean flag)595 krb5_rd_req_in_set_pac_check(krb5_context context,
596 krb5_rd_req_in_ctx in,
597 krb5_boolean flag)
598 {
599 in->check_pac = flag;
600 return 0;
601 }
602
603
604 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_in_set_keyblock(krb5_context context,krb5_rd_req_in_ctx in,krb5_keyblock * keyblock)605 krb5_rd_req_in_set_keyblock(krb5_context context,
606 krb5_rd_req_in_ctx in,
607 krb5_keyblock *keyblock)
608 {
609 in->keyblock = keyblock; /* XXX should make copy */
610 return 0;
611 }
612
613 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_out_get_ap_req_options(krb5_context context,krb5_rd_req_out_ctx out,krb5_flags * ap_req_options)614 krb5_rd_req_out_get_ap_req_options(krb5_context context,
615 krb5_rd_req_out_ctx out,
616 krb5_flags *ap_req_options)
617 {
618 *ap_req_options = out->ap_req_options;
619 return 0;
620 }
621
622 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_out_get_ticket(krb5_context context,krb5_rd_req_out_ctx out,krb5_ticket ** ticket)623 krb5_rd_req_out_get_ticket(krb5_context context,
624 krb5_rd_req_out_ctx out,
625 krb5_ticket **ticket)
626 {
627 return krb5_copy_ticket(context, out->ticket, ticket);
628 }
629
630 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_out_get_keyblock(krb5_context context,krb5_rd_req_out_ctx out,krb5_keyblock ** keyblock)631 krb5_rd_req_out_get_keyblock(krb5_context context,
632 krb5_rd_req_out_ctx out,
633 krb5_keyblock **keyblock)
634 {
635 return krb5_copy_keyblock(context, out->keyblock, keyblock);
636 }
637
638 /**
639 * Get the principal that was used in the request from the
640 * client. Might not match whats in the ticket if krb5_rd_req_ctx()
641 * searched in the keytab for a matching key.
642 *
643 * @param context a Kerberos 5 context.
644 * @param out a krb5_rd_req_out_ctx from krb5_rd_req_ctx().
645 * @param principal return principal, free with krb5_free_principal().
646 *
647 * @ingroup krb5_auth
648 */
649
650 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_out_get_server(krb5_context context,krb5_rd_req_out_ctx out,krb5_principal * principal)651 krb5_rd_req_out_get_server(krb5_context context,
652 krb5_rd_req_out_ctx out,
653 krb5_principal *principal)
654 {
655 return krb5_copy_principal(context, out->server, principal);
656 }
657
658 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_rd_req_in_ctx_free(krb5_context context,krb5_rd_req_in_ctx ctx)659 krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx)
660 {
661 free(ctx);
662 }
663
664 /**
665 * Free the krb5_rd_req_out_ctx.
666 *
667 * @param context Keberos 5 context.
668 * @param ctx krb5_rd_req_out_ctx context to free.
669 *
670 * @ingroup krb5_auth
671 */
672
673 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_rd_req_out_ctx_free(krb5_context context,krb5_rd_req_out_ctx ctx)674 krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx)
675 {
676 if (ctx->ticket)
677 krb5_free_ticket(context, ctx->ticket);
678 if (ctx->keyblock)
679 krb5_free_keyblock(context, ctx->keyblock);
680 if (ctx->server)
681 krb5_free_principal(context, ctx->server);
682 free(ctx);
683 }
684
685 /*
686 *
687 */
688
689 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req(krb5_context context,krb5_auth_context * auth_context,const krb5_data * inbuf,krb5_const_principal server,krb5_keytab keytab,krb5_flags * ap_req_options,krb5_ticket ** ticket)690 krb5_rd_req(krb5_context context,
691 krb5_auth_context *auth_context,
692 const krb5_data *inbuf,
693 krb5_const_principal server,
694 krb5_keytab keytab,
695 krb5_flags *ap_req_options,
696 krb5_ticket **ticket)
697 {
698 krb5_error_code ret;
699 krb5_rd_req_in_ctx in;
700 krb5_rd_req_out_ctx out;
701
702 ret = krb5_rd_req_in_ctx_alloc(context, &in);
703 if (ret)
704 return ret;
705
706 ret = krb5_rd_req_in_set_keytab(context, in, keytab);
707 if (ret) {
708 krb5_rd_req_in_ctx_free(context, in);
709 return ret;
710 }
711
712 ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
713 krb5_rd_req_in_ctx_free(context, in);
714 if (ret)
715 return ret;
716
717 if (ap_req_options)
718 *ap_req_options = out->ap_req_options;
719 if (ticket) {
720 ret = krb5_copy_ticket(context, out->ticket, ticket);
721 if (ret)
722 goto out;
723 }
724
725 out:
726 krb5_rd_req_out_ctx_free(context, out);
727 return ret;
728 }
729
730 /*
731 *
732 */
733
734 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_with_keyblock(krb5_context context,krb5_auth_context * auth_context,const krb5_data * inbuf,krb5_const_principal server,krb5_keyblock * keyblock,krb5_flags * ap_req_options,krb5_ticket ** ticket)735 krb5_rd_req_with_keyblock(krb5_context context,
736 krb5_auth_context *auth_context,
737 const krb5_data *inbuf,
738 krb5_const_principal server,
739 krb5_keyblock *keyblock,
740 krb5_flags *ap_req_options,
741 krb5_ticket **ticket)
742 {
743 krb5_error_code ret;
744 krb5_rd_req_in_ctx in;
745 krb5_rd_req_out_ctx out;
746
747 ret = krb5_rd_req_in_ctx_alloc(context, &in);
748 if (ret)
749 return ret;
750
751 ret = krb5_rd_req_in_set_keyblock(context, in, keyblock);
752 if (ret) {
753 krb5_rd_req_in_ctx_free(context, in);
754 return ret;
755 }
756
757 ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
758 krb5_rd_req_in_ctx_free(context, in);
759 if (ret)
760 return ret;
761
762 if (ap_req_options)
763 *ap_req_options = out->ap_req_options;
764 if (ticket) {
765 ret = krb5_copy_ticket(context, out->ticket, ticket);
766 if (ret)
767 goto out;
768 }
769
770 out:
771 krb5_rd_req_out_ctx_free(context, out);
772 return ret;
773 }
774
775 /*
776 *
777 */
778
779 static krb5_error_code
get_key_from_keytab(krb5_context context,krb5_ap_req * ap_req,krb5_const_principal server,krb5_keytab keytab,krb5_keyblock ** out_key)780 get_key_from_keytab(krb5_context context,
781 krb5_ap_req *ap_req,
782 krb5_const_principal server,
783 krb5_keytab keytab,
784 krb5_keyblock **out_key)
785 {
786 krb5_keytab_entry entry;
787 krb5_error_code ret;
788 int kvno;
789 krb5_keytab real_keytab;
790
791 if(keytab == NULL)
792 krb5_kt_default(context, &real_keytab);
793 else
794 real_keytab = keytab;
795
796 if (ap_req->ticket.enc_part.kvno)
797 kvno = *ap_req->ticket.enc_part.kvno;
798 else
799 kvno = 0;
800
801 ret = krb5_kt_get_entry (context,
802 real_keytab,
803 server,
804 kvno,
805 ap_req->ticket.enc_part.etype,
806 &entry);
807 if(ret)
808 goto out;
809 ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
810 krb5_kt_free_entry (context, &entry);
811 out:
812 if(keytab == NULL)
813 krb5_kt_close(context, real_keytab);
814
815 return ret;
816 }
817
818 /**
819 * The core server function that verify application authentication
820 * requests from clients.
821 *
822 * @param context Keberos 5 context.
823 * @param auth_context the authentication context, can be NULL, then
824 * default values for the authentication context will used.
825 * @param inbuf the (AP-REQ) authentication buffer
826 *
827 * @param server the server with authenticate as, if NULL the function
828 * will try to find any available credential in the keytab
829 * that will verify the reply. The function will prefer the
830 * server the server client specified in the AP-REQ, but if
831 * there is no mach, it will try all keytab entries for a
832 * match. This have serious performance issues for larger keytabs.
833 *
834 * @param inctx control the behavior of the function, if NULL, the
835 * default behavior is used.
836 * @param outctx the return outctx, free with krb5_rd_req_out_ctx_free().
837 * @return Kerberos 5 error code, see krb5_get_error_message().
838 *
839 * @ingroup krb5_auth
840 */
841
842 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_rd_req_ctx(krb5_context context,krb5_auth_context * auth_context,const krb5_data * inbuf,krb5_const_principal server,krb5_rd_req_in_ctx inctx,krb5_rd_req_out_ctx * outctx)843 krb5_rd_req_ctx(krb5_context context,
844 krb5_auth_context *auth_context,
845 const krb5_data *inbuf,
846 krb5_const_principal server,
847 krb5_rd_req_in_ctx inctx,
848 krb5_rd_req_out_ctx *outctx)
849 {
850 krb5_error_code ret;
851 krb5_ap_req ap_req;
852 krb5_rd_req_out_ctx o = NULL;
853 krb5_keytab id = NULL, keytab = NULL;
854 krb5_principal service = NULL;
855
856 *outctx = NULL;
857
858 o = calloc(1, sizeof(*o));
859 if (o == NULL) {
860 krb5_set_error_message(context, ENOMEM,
861 N_("malloc: out of memory", ""));
862 return ENOMEM;
863 }
864
865 if (*auth_context == NULL) {
866 ret = krb5_auth_con_init(context, auth_context);
867 if (ret)
868 goto out;
869 }
870
871 ret = krb5_decode_ap_req(context, inbuf, &ap_req);
872 if(ret)
873 goto out;
874
875 /* Save that principal that was in the request */
876 ret = _krb5_principalname2krb5_principal(context,
877 &o->server,
878 ap_req.ticket.sname,
879 ap_req.ticket.realm);
880 if (ret)
881 goto out;
882
883 if (ap_req.ap_options.use_session_key &&
884 (*auth_context)->keyblock == NULL) {
885 ret = KRB5KRB_AP_ERR_NOKEY;
886 krb5_set_error_message(context, ret,
887 N_("krb5_rd_req: user to user auth "
888 "without session key given", ""));
889 goto out;
890 }
891
892 if (inctx && inctx->keytab)
893 id = inctx->keytab;
894
895 if((*auth_context)->keyblock){
896 ret = krb5_copy_keyblock(context,
897 (*auth_context)->keyblock,
898 &o->keyblock);
899 if (ret)
900 goto out;
901 } else if(inctx && inctx->keyblock){
902 ret = krb5_copy_keyblock(context,
903 inctx->keyblock,
904 &o->keyblock);
905 if (ret)
906 goto out;
907 } else {
908
909 if(id == NULL) {
910 krb5_kt_default(context, &keytab);
911 id = keytab;
912 }
913 if (id == NULL)
914 goto out;
915
916 if (server == NULL) {
917 ret = _krb5_principalname2krb5_principal(context,
918 &service,
919 ap_req.ticket.sname,
920 ap_req.ticket.realm);
921 if (ret)
922 goto out;
923 server = service;
924 }
925
926 ret = get_key_from_keytab(context,
927 &ap_req,
928 server,
929 id,
930 &o->keyblock);
931 if (ret) {
932 /* If caller specified a server, fail. */
933 if (service == NULL && (context->flags & KRB5_CTX_F_RD_REQ_IGNORE) == 0)
934 goto out;
935 /* Otherwise, fall back to iterating over the keytab. This
936 * have serious performace issues for larger keytab.
937 */
938 o->keyblock = NULL;
939 }
940 }
941
942 if (o->keyblock) {
943 /*
944 * We got an exact keymatch, use that.
945 */
946
947 ret = krb5_verify_ap_req2(context,
948 auth_context,
949 &ap_req,
950 server,
951 o->keyblock,
952 0,
953 &o->ap_req_options,
954 &o->ticket,
955 KRB5_KU_AP_REQ_AUTH);
956
957 if (ret)
958 goto out;
959
960 } else {
961 /*
962 * Interate over keytab to find a key that can decrypt the request.
963 */
964
965 krb5_keytab_entry entry;
966 krb5_kt_cursor cursor;
967 int done = 0, kvno = 0;
968
969 memset(&cursor, 0, sizeof(cursor));
970
971 if (ap_req.ticket.enc_part.kvno)
972 kvno = *ap_req.ticket.enc_part.kvno;
973
974 ret = krb5_kt_start_seq_get(context, id, &cursor);
975 if (ret)
976 goto out;
977
978 done = 0;
979 while (!done) {
980 krb5_principal p;
981
982 ret = krb5_kt_next_entry(context, id, &entry, &cursor);
983 if (ret) {
984 _krb5_kt_principal_not_found(context, ret, id, o->server,
985 ap_req.ticket.enc_part.etype,
986 kvno);
987 goto out;
988 }
989
990 if (entry.keyblock.keytype != ap_req.ticket.enc_part.etype) {
991 krb5_kt_free_entry (context, &entry);
992 continue;
993 }
994
995 ret = krb5_verify_ap_req2(context,
996 auth_context,
997 &ap_req,
998 server,
999 &entry.keyblock,
1000 0,
1001 &o->ap_req_options,
1002 &o->ticket,
1003 KRB5_KU_AP_REQ_AUTH);
1004 if (ret) {
1005 krb5_kt_free_entry (context, &entry);
1006 continue;
1007 }
1008
1009 /*
1010 * Found a match, save the keyblock for PAC processing,
1011 * and update the service principal in the ticket to match
1012 * whatever is in the keytab.
1013 */
1014
1015 ret = krb5_copy_keyblock(context,
1016 &entry.keyblock,
1017 &o->keyblock);
1018 if (ret) {
1019 krb5_kt_free_entry (context, &entry);
1020 goto out;
1021 }
1022
1023 ret = krb5_copy_principal(context, entry.principal, &p);
1024 if (ret) {
1025 krb5_kt_free_entry (context, &entry);
1026 goto out;
1027 }
1028 krb5_free_principal(context, o->ticket->server);
1029 o->ticket->server = p;
1030
1031 krb5_kt_free_entry (context, &entry);
1032
1033 done = 1;
1034 }
1035 krb5_kt_end_seq_get (context, id, &cursor);
1036 }
1037
1038 /* If there is a PAC, verify its server signature */
1039 if (inctx == NULL || inctx->check_pac) {
1040 krb5_pac pac;
1041 krb5_data data;
1042
1043 ret = krb5_ticket_get_authorization_data_type(context,
1044 o->ticket,
1045 KRB5_AUTHDATA_WIN2K_PAC,
1046 &data);
1047 if (ret == 0) {
1048 ret = krb5_pac_parse(context, data.data, data.length, &pac);
1049 krb5_data_free(&data);
1050 if (ret)
1051 goto out;
1052
1053 ret = krb5_pac_verify(context,
1054 pac,
1055 o->ticket->ticket.authtime,
1056 o->ticket->client,
1057 o->keyblock,
1058 NULL);
1059 krb5_pac_free(context, pac);
1060 if (ret)
1061 goto out;
1062 } else
1063 ret = 0;
1064 }
1065 out:
1066
1067 if (ret || outctx == NULL) {
1068 krb5_rd_req_out_ctx_free(context, o);
1069 } else
1070 *outctx = o;
1071
1072 free_AP_REQ(&ap_req);
1073
1074 if (service)
1075 krb5_free_principal(context, service);
1076
1077 if (keytab)
1078 krb5_kt_close(context, keytab);
1079
1080 return ret;
1081 }
1082