xref: /netbsd-src/crypto/external/bsd/heimdal/dist/lib/krb5/ticket.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: ticket.c,v 1.5 2019/12/15 22:50:50 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  *
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * 3. Neither the name of the Institute nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include "krb5_locl.h"
39 
40 /**
41  * Free ticket and content
42  *
43  * @param context a Kerberos 5 context
44  * @param ticket ticket to free
45  *
46  * @return Returns 0 to indicate success.  Otherwise an kerberos et
47  * error code is returned, see krb5_get_error_message().
48  *
49  * @ingroup krb5
50  */
51 
52 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
53 krb5_free_ticket(krb5_context context,
54 		 krb5_ticket *ticket)
55 {
56     free_EncTicketPart(&ticket->ticket);
57     krb5_free_principal(context, ticket->client);
58     krb5_free_principal(context, ticket->server);
59     free(ticket);
60     return 0;
61 }
62 
63 /**
64  * Copy ticket and content
65  *
66  * @param context a Kerberos 5 context
67  * @param from ticket to copy
68  * @param to new copy of ticket, free with krb5_free_ticket()
69  *
70  * @return Returns 0 to indicate success.  Otherwise an kerberos et
71  * error code is returned, see krb5_get_error_message().
72  *
73  * @ingroup krb5
74  */
75 
76 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
77 krb5_copy_ticket(krb5_context context,
78 		 const krb5_ticket *from,
79 		 krb5_ticket **to)
80 {
81     krb5_error_code ret;
82     krb5_ticket *tmp;
83 
84     *to = NULL;
85     tmp = malloc(sizeof(*tmp));
86     if (tmp == NULL)
87 	return krb5_enomem(context);
88     if((ret = copy_EncTicketPart(&from->ticket, &tmp->ticket))){
89 	free(tmp);
90 	return ret;
91     }
92     ret = krb5_copy_principal(context, from->client, &tmp->client);
93     if(ret){
94 	free_EncTicketPart(&tmp->ticket);
95 	free(tmp);
96 	return ret;
97     }
98     ret = krb5_copy_principal(context, from->server, &tmp->server);
99     if(ret){
100 	krb5_free_principal(context, tmp->client);
101 	free_EncTicketPart(&tmp->ticket);
102 	free(tmp);
103 	return ret;
104     }
105     *to = tmp;
106     return 0;
107 }
108 
109 /**
110  * Return client principal in ticket
111  *
112  * @param context a Kerberos 5 context
113  * @param ticket ticket to copy
114  * @param client client principal, free with krb5_free_principal()
115  *
116  * @return Returns 0 to indicate success.  Otherwise an kerberos et
117  * error code is returned, see krb5_get_error_message().
118  *
119  * @ingroup krb5
120  */
121 
122 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
123 krb5_ticket_get_client(krb5_context context,
124 		       const krb5_ticket *ticket,
125 		       krb5_principal *client)
126 {
127     return krb5_copy_principal(context, ticket->client, client);
128 }
129 
130 /**
131  * Return server principal in ticket
132  *
133  * @param context a Kerberos 5 context
134  * @param ticket ticket to copy
135  * @param server server principal, free with krb5_free_principal()
136  *
137  * @return Returns 0 to indicate success.  Otherwise an kerberos et
138  * error code is returned, see krb5_get_error_message().
139  *
140  * @ingroup krb5
141  */
142 
143 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
144 krb5_ticket_get_server(krb5_context context,
145 		       const krb5_ticket *ticket,
146 		       krb5_principal *server)
147 {
148     return krb5_copy_principal(context, ticket->server, server);
149 }
150 
151 /**
152  * Return end time of ticket
153  *
154  * @param context a Kerberos 5 context
155  * @param ticket ticket to copy
156  *
157  * @return end time of ticket
158  *
159  * @ingroup krb5
160  */
161 
162 KRB5_LIB_FUNCTION time_t KRB5_LIB_CALL
163 krb5_ticket_get_endtime(krb5_context context,
164 			const krb5_ticket *ticket)
165 {
166     return ticket->ticket.endtime;
167 }
168 
169 /**
170  * Get the flags from the Kerberos ticket
171  *
172  * @param context Kerberos context
173  * @param ticket Kerberos ticket
174  *
175  * @return ticket flags
176  *
177  * @ingroup krb5_ticket
178  */
179 KRB5_LIB_FUNCTION unsigned long KRB5_LIB_CALL
180 krb5_ticket_get_flags(krb5_context context,
181 		      const krb5_ticket *ticket)
182 {
183     return TicketFlags2int(ticket->ticket.flags);
184 }
185 
186 static int
187 find_type_in_ad(krb5_context context,
188 		int type,
189 		krb5_data *data,
190 		krb5_boolean *found,
191 		krb5_boolean failp,
192 		krb5_keyblock *sessionkey,
193 		const AuthorizationData *ad,
194 		int level)
195 {
196     krb5_error_code ret = 0;
197     size_t i;
198 
199     if (level > 9) {
200 	ret = ENOENT; /* XXX */
201 	krb5_set_error_message(context, ret,
202 			       N_("Authorization data nested deeper "
203 				  "then %d levels, stop searching", ""),
204 			       level);
205 	goto out;
206     }
207 
208     /*
209      * Only copy out the element the first time we get to it, we need
210      * to run over the whole authorization data fields to check if
211      * there are any container clases we need to care about.
212      */
213     for (i = 0; i < ad->len; i++) {
214 	if (!*found && ad->val[i].ad_type == type) {
215 	    ret = der_copy_octet_string(&ad->val[i].ad_data, data);
216 	    if (ret) {
217 		krb5_set_error_message(context, ret,
218 				       N_("malloc: out of memory", ""));
219 		goto out;
220 	    }
221 	    *found = TRUE;
222 	    continue;
223 	}
224 	switch (ad->val[i].ad_type) {
225 	case KRB5_AUTHDATA_IF_RELEVANT: {
226 	    AuthorizationData child;
227 	    ret = decode_AuthorizationData(ad->val[i].ad_data.data,
228 					   ad->val[i].ad_data.length,
229 					   &child,
230 					   NULL);
231 	    if (ret) {
232 		krb5_set_error_message(context, ret,
233 				       N_("Failed to decode "
234 					  "IF_RELEVANT with %d", ""),
235 				       (int)ret);
236 		goto out;
237 	    }
238 	    ret = find_type_in_ad(context, type, data, found, FALSE,
239 				  sessionkey, &child, level + 1);
240 	    free_AuthorizationData(&child);
241 	    if (ret)
242 		goto out;
243 	    break;
244 	}
245 #if 0 /* XXX test */
246 	case KRB5_AUTHDATA_KDC_ISSUED: {
247 	    AD_KDCIssued child;
248 
249 	    ret = decode_AD_KDCIssued(ad->val[i].ad_data.data,
250 				      ad->val[i].ad_data.length,
251 				      &child,
252 				      NULL);
253 	    if (ret) {
254 		krb5_set_error_message(context, ret,
255 				       N_("Failed to decode "
256 					  "AD_KDCIssued with %d", ""),
257 				       ret);
258 		goto out;
259 	    }
260 	    if (failp) {
261 		krb5_boolean valid;
262 		krb5_data buf;
263 		size_t len;
264 
265 		ASN1_MALLOC_ENCODE(AuthorizationData, buf.data, buf.length,
266 				   &child.elements, &len, ret);
267 		if (ret) {
268 		    free_AD_KDCIssued(&child);
269 		    krb5_clear_error_message(context);
270 		    goto out;
271 		}
272 		if(buf.length != len)
273 		    krb5_abortx(context, "internal error in ASN.1 encoder");
274 
275 		ret = krb5_c_verify_checksum(context, sessionkey, 19, &buf,
276 					     &child.ad_checksum, &valid);
277 		krb5_data_free(&buf);
278 		if (ret) {
279 		    free_AD_KDCIssued(&child);
280 		    goto out;
281 		}
282 		if (!valid) {
283 		    krb5_clear_error_message(context);
284 		    ret = ENOENT;
285 		    free_AD_KDCIssued(&child);
286 		    goto out;
287 		}
288 	    }
289 	    ret = find_type_in_ad(context, type, data, found, failp, sessionkey,
290 				  &child.elements, level + 1);
291 	    free_AD_KDCIssued(&child);
292 	    if (ret)
293 		goto out;
294 	    break;
295 	}
296 #endif
297 	case KRB5_AUTHDATA_AND_OR:
298 	    if (!failp)
299 		break;
300 	    ret = ENOENT; /* XXX */
301 	    krb5_set_error_message(context, ret,
302 				   N_("Authorization data contains "
303 				      "AND-OR element that is unknown to the "
304 				      "application", ""));
305 	    goto out;
306 	default:
307 	    if (!failp)
308 		break;
309 	    ret = ENOENT; /* XXX */
310 	    krb5_set_error_message(context, ret,
311 				   N_("Authorization data contains "
312 				      "unknown type (%d) ", ""),
313 				   ad->val[i].ad_type);
314 	    goto out;
315 	}
316     }
317 out:
318     if (ret) {
319 	if (*found) {
320 	    krb5_data_free(data);
321 	    *found = 0;
322 	}
323     }
324     return ret;
325 }
326 
327 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
328 _krb5_get_ad(krb5_context context,
329 	     const AuthorizationData *ad,
330 	     krb5_keyblock *sessionkey,
331 	     int type,
332 	     krb5_data *data)
333 {
334     krb5_boolean found = FALSE;
335     krb5_error_code ret;
336 
337     krb5_data_zero(data);
338 
339     if (ad == NULL) {
340 	krb5_set_error_message(context, ENOENT,
341 			       N_("No authorization data", ""));
342 	return ENOENT; /* XXX */
343     }
344 
345     ret = find_type_in_ad(context, type, data, &found, TRUE, sessionkey, ad, 0);
346     if (ret)
347 	return ret;
348     if (!found) {
349 	krb5_set_error_message(context, ENOENT,
350 			       N_("Have no authorization data of type %d", ""),
351 			       type);
352 	return ENOENT; /* XXX */
353     }
354     return 0;
355 }
356 
357 
358 /**
359  * Extract the authorization data type of type from the ticket. Store
360  * the field in data. This function is to use for kerberos
361  * applications.
362  *
363  * @param context a Kerberos 5 context
364  * @param ticket Kerberos ticket
365  * @param type type to fetch
366  * @param data returned data, free with krb5_data_free()
367  *
368  * @ingroup krb5
369  */
370 
371 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
372 krb5_ticket_get_authorization_data_type(krb5_context context,
373 					krb5_ticket *ticket,
374 					int type,
375 					krb5_data *data)
376 {
377     AuthorizationData *ad;
378     krb5_error_code ret;
379     krb5_boolean found = FALSE;
380 
381     krb5_data_zero(data);
382 
383     ad = ticket->ticket.authorization_data;
384     if (ticket->ticket.authorization_data == NULL) {
385 	krb5_set_error_message(context, ENOENT,
386 			       N_("Ticket have not authorization data", ""));
387 	return ENOENT; /* XXX */
388     }
389 
390     ret = find_type_in_ad(context, type, data, &found, TRUE,
391 			  &ticket->ticket.key, ad, 0);
392     if (ret)
393 	return ret;
394     if (!found) {
395 	krb5_set_error_message(context, ENOENT,
396 			       N_("Ticket have not "
397 				  "authorization data of type %d", ""),
398 			       type);
399 	return ENOENT; /* XXX */
400     }
401     return 0;
402 }
403 
404 static krb5_error_code
405 check_server_referral(krb5_context context,
406 		      krb5_kdc_rep *rep,
407 		      unsigned flags,
408 		      krb5_const_principal requested,
409 		      krb5_const_principal returned,
410 		      krb5_keyblock * key)
411 {
412     krb5_error_code ret;
413     PA_ServerReferralData ref;
414     krb5_crypto session;
415     EncryptedData ed;
416     size_t len;
417     krb5_data data;
418     PA_DATA *pa;
419     int i = 0, cmp;
420 
421     if (rep->kdc_rep.padata == NULL)
422 	goto noreferral;
423 
424     pa = krb5_find_padata(rep->kdc_rep.padata->val,
425 			  rep->kdc_rep.padata->len,
426 			  KRB5_PADATA_SERVER_REFERRAL, &i);
427     if (pa == NULL)
428 	goto noreferral;
429 
430     memset(&ed, 0, sizeof(ed));
431     memset(&ref, 0, sizeof(ref));
432 
433     ret = decode_EncryptedData(pa->padata_value.data,
434 			       pa->padata_value.length,
435 			       &ed, &len);
436     if (ret)
437 	return ret;
438     if (len != pa->padata_value.length) {
439 	free_EncryptedData(&ed);
440 	krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
441 			       N_("Referral EncryptedData wrong for realm %s",
442 				  "realm"), requested->realm);
443 	return KRB5KRB_AP_ERR_MODIFIED;
444     }
445 
446     ret = krb5_crypto_init(context, key, 0, &session);
447     if (ret) {
448 	free_EncryptedData(&ed);
449 	return ret;
450     }
451 
452     ret = krb5_decrypt_EncryptedData(context, session,
453 				     KRB5_KU_PA_SERVER_REFERRAL,
454 				     &ed, &data);
455     free_EncryptedData(&ed);
456     krb5_crypto_destroy(context, session);
457     if (ret)
458 	return ret;
459 
460     ret = decode_PA_ServerReferralData(data.data, data.length, &ref, &len);
461     if (ret) {
462 	krb5_data_free(&data);
463 	return ret;
464     }
465     krb5_data_free(&data);
466 
467     if (strcmp(requested->realm, returned->realm) != 0) {
468 	free_PA_ServerReferralData(&ref);
469 	krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
470 			       N_("server ref realm mismatch, "
471 				  "requested realm %s got back %s", ""),
472 			       requested->realm, returned->realm);
473 	return KRB5KRB_AP_ERR_MODIFIED;
474     }
475 
476     if (krb5_principal_is_krbtgt(context, returned)) {
477 	const char *realm = returned->name.name_string.val[1];
478 
479 	if (ref.referred_realm == NULL
480 	    || strcmp(*ref.referred_realm, realm) != 0)
481 	{
482 	    free_PA_ServerReferralData(&ref);
483 	    krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
484 				   N_("tgt returned with wrong ref", ""));
485 	    return KRB5KRB_AP_ERR_MODIFIED;
486 	}
487     } else if (krb5_principal_compare(context, returned, requested) == 0) {
488 	free_PA_ServerReferralData(&ref);
489 	krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
490 			       N_("req princ no same as returned", ""));
491 	return KRB5KRB_AP_ERR_MODIFIED;
492     }
493 
494     if (ref.requested_principal_name) {
495 	cmp = _krb5_principal_compare_PrincipalName(context,
496 						    requested,
497 						    ref.requested_principal_name);
498 	if (!cmp) {
499 	    free_PA_ServerReferralData(&ref);
500 	    krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
501 				   N_("referred principal not same "
502 				      "as requested", ""));
503 	    return KRB5KRB_AP_ERR_MODIFIED;
504 	}
505     } else if (flags & EXTRACT_TICKET_AS_REQ) {
506 	free_PA_ServerReferralData(&ref);
507 	krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
508 			       N_("Requested principal missing on AS-REQ", ""));
509 	return KRB5KRB_AP_ERR_MODIFIED;
510     }
511 
512     free_PA_ServerReferralData(&ref);
513 
514     return ret;
515 noreferral:
516     /*
517      * Expect excact match or that we got a krbtgt
518      */
519     if (krb5_principal_compare(context, requested, returned) != TRUE &&
520 	(krb5_realm_compare(context, requested, returned) != TRUE &&
521 	 krb5_principal_is_krbtgt(context, returned) != TRUE))
522     {
523 	krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
524 			       N_("Not same server principal returned "
525 				  "as requested", ""));
526 	return KRB5KRB_AP_ERR_MODIFIED;
527     }
528     return 0;
529 }
530 
531 /*
532  * Verify KDC supported anonymous if requested
533  */
534 static krb5_error_code
535 check_client_anonymous(krb5_context context,
536 		       krb5_kdc_rep *rep,
537 		       krb5_const_principal requested,
538 		       krb5_const_principal mapped,
539 		       krb5_boolean is_tgs_rep)
540 {
541     int flags;
542 
543     if (!rep->enc_part.flags.anonymous)
544 	return KRB5KDC_ERR_BADOPTION;
545 
546     if (is_tgs_rep)
547 	flags = KRB5_ANON_MATCH_ANY;
548     else if (krb5_principal_is_anonymous(context, requested, KRB5_ANON_MATCH_ANY))
549 	flags = KRB5_ANON_MATCH_UNAUTHENTICATED;
550     else
551 	flags = KRB5_ANON_MATCH_AUTHENTICATED;
552 
553     if (!krb5_principal_is_anonymous(context, mapped, flags))
554 	return KRB5KRB_AP_ERR_MODIFIED;
555 
556     return 0;
557 }
558 
559 /*
560  * Verify returned client principal name in anonymous/referral case
561  */
562 
563 static krb5_error_code
564 check_client_mismatch(krb5_context context,
565 		      krb5_kdc_rep *rep,
566 		      krb5_const_principal requested,
567 		      krb5_const_principal mapped,
568 		      krb5_keyblock const * key)
569 {
570     if (rep->enc_part.flags.anonymous) {
571 	if (!krb5_principal_is_anonymous(context, mapped, KRB5_ANON_MATCH_ANY)) {
572 	    krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
573 				   N_("Anonymous ticket does not contain anonymous "
574 				      "principal", ""));
575 	    return KRB5KRB_AP_ERR_MODIFIED;
576 	}
577     } else {
578 	if (krb5_principal_compare(context, requested, mapped) == FALSE &&
579 	    !rep->enc_part.flags.enc_pa_rep) {
580 	    krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
581 				   N_("Not same client principal returned "
582 				   "as requested", ""));
583 	    return KRB5KRB_AP_ERR_MODIFIED;
584 	}
585     }
586 
587     return 0;
588 }
589 
590 
591 static krb5_error_code KRB5_CALLCONV
592 decrypt_tkt (krb5_context context,
593 	     krb5_keyblock *key,
594 	     krb5_key_usage usage,
595 	     krb5_const_pointer decrypt_arg,
596 	     krb5_kdc_rep *dec_rep)
597 {
598     krb5_error_code ret;
599     krb5_data data;
600     size_t size;
601     krb5_crypto crypto;
602 
603     ret = krb5_crypto_init(context, key, 0, &crypto);
604     if (ret)
605 	return ret;
606 
607     ret = krb5_decrypt_EncryptedData (context,
608 				      crypto,
609 				      usage,
610 				      &dec_rep->kdc_rep.enc_part,
611 				      &data);
612     krb5_crypto_destroy(context, crypto);
613 
614     if (ret)
615 	return ret;
616 
617     ret = decode_EncASRepPart(data.data,
618 			      data.length,
619 			      &dec_rep->enc_part,
620 			      &size);
621     if (ret)
622 	ret = decode_EncTGSRepPart(data.data,
623 				   data.length,
624 				   &dec_rep->enc_part,
625 				   &size);
626     krb5_data_free (&data);
627     if (ret) {
628         krb5_set_error_message(context, ret,
629 			       N_("Failed to decode encpart in ticket", ""));
630 	return ret;
631     }
632     return 0;
633 }
634 
635 KRB5_LIB_FUNCTION int KRB5_LIB_CALL
636 _krb5_extract_ticket(krb5_context context,
637 		     krb5_kdc_rep *rep,
638 		     krb5_creds *creds,
639 		     krb5_keyblock *key,
640 		     krb5_const_pointer keyseed,
641 		     krb5_key_usage key_usage,
642 		     krb5_addresses *addrs,
643 		     unsigned nonce,
644 		     unsigned flags,
645 		     krb5_data *request,
646 		     krb5_decrypt_proc decrypt_proc,
647 		     krb5_const_pointer decryptarg)
648 {
649     krb5_error_code ret;
650     krb5_principal tmp_principal;
651     size_t len = 0;
652     time_t tmp_time;
653     krb5_timestamp sec_now;
654 
655     /* decrypt */
656 
657     if (decrypt_proc == NULL)
658 	decrypt_proc = decrypt_tkt;
659 
660     ret = (*decrypt_proc)(context, key, key_usage, decryptarg, rep);
661     if (ret)
662 	goto out;
663 
664     if (rep->enc_part.flags.enc_pa_rep && request) {
665 	krb5_crypto crypto = NULL;
666 	Checksum cksum;
667 	PA_DATA *pa = NULL;
668 	int idx = 0;
669 
670 	_krb5_debug(context, 5, "processing enc-ap-rep");
671 
672 	if (rep->enc_part.encrypted_pa_data == NULL ||
673 	    (pa = krb5_find_padata(rep->enc_part.encrypted_pa_data->val,
674 				   rep->enc_part.encrypted_pa_data->len,
675 				   KRB5_PADATA_REQ_ENC_PA_REP,
676 				   &idx)) == NULL)
677 	{
678 	    _krb5_debug(context, 5, "KRB5_PADATA_REQ_ENC_PA_REP missing");
679 	    ret = KRB5KRB_AP_ERR_MODIFIED;
680 	    goto out;
681 	}
682 
683 	ret = krb5_crypto_init(context, key, 0, &crypto);
684 	if (ret)
685 	    goto out;
686 
687 	ret = decode_Checksum(pa->padata_value.data,
688 			      pa->padata_value.length,
689 			      &cksum, NULL);
690 	if (ret) {
691 	    krb5_crypto_destroy(context, crypto);
692 	    goto out;
693 	}
694 
695 	ret = krb5_verify_checksum(context, crypto,
696 				   KRB5_KU_AS_REQ,
697 				   request->data, request->length,
698 				   &cksum);
699 	krb5_crypto_destroy(context, crypto);
700 	free_Checksum(&cksum);
701 	_krb5_debug(context, 5, "enc-ap-rep: %svalid", (ret == 0) ? "" : "in");
702 	if (ret)
703 	    goto out;
704     }
705 
706     /* save session key */
707 
708     creds->session.keyvalue.length = 0;
709     creds->session.keyvalue.data   = NULL;
710     creds->session.keytype = rep->enc_part.key.keytype;
711     ret = krb5_data_copy (&creds->session.keyvalue,
712 			  rep->enc_part.key.keyvalue.data,
713 			  rep->enc_part.key.keyvalue.length);
714     if (ret) {
715 	krb5_clear_error_message(context);
716 	goto out;
717     }
718 
719     /* compare client and save */
720     ret = _krb5_principalname2krb5_principal(context,
721 					     &tmp_principal,
722 					     rep->kdc_rep.cname,
723 					     rep->kdc_rep.crealm);
724     if (ret)
725 	goto out;
726 
727     /* check KDC supported anonymous if it was requested */
728     if (flags & EXTRACT_TICKET_MATCH_ANON) {
729 	ret = check_client_anonymous(context,rep,
730 				     creds->client,
731 				     tmp_principal,
732 				     request == NULL); /* is TGS */
733 	if (ret) {
734 	    krb5_free_principal(context, tmp_principal);
735 	    goto out;
736 	}
737     }
738 
739     /* check client referral and save principal */
740     if((flags & EXTRACT_TICKET_ALLOW_CNAME_MISMATCH) == 0) {
741 	ret = check_client_mismatch(context, rep,
742 				    creds->client,
743 				    tmp_principal,
744 				    &creds->session);
745 	if (ret) {
746 	    krb5_free_principal (context, tmp_principal);
747 	    goto out;
748 	}
749     }
750     krb5_free_principal (context, creds->client);
751     creds->client = tmp_principal;
752 
753     /* check server referral and save principal */
754     ret = _krb5_principalname2krb5_principal (context,
755 					      &tmp_principal,
756 					      rep->enc_part.sname,
757 					      rep->enc_part.srealm);
758     if (ret)
759 	goto out;
760     if((flags & EXTRACT_TICKET_ALLOW_SERVER_MISMATCH) == 0){
761 	ret = check_server_referral(context,
762 				    rep,
763 				    flags,
764 				    creds->server,
765 				    tmp_principal,
766 				    &creds->session);
767 	if (ret) {
768 	    krb5_free_principal (context, tmp_principal);
769 	    goto out;
770 	}
771     }
772     krb5_free_principal(context, creds->server);
773     creds->server = tmp_principal;
774 
775     /* verify names */
776     if(flags & EXTRACT_TICKET_MATCH_REALM){
777 	const char *srealm = krb5_principal_get_realm(context, creds->server);
778 	const char *crealm = krb5_principal_get_realm(context, creds->client);
779 
780 	if (strcmp(rep->enc_part.srealm, srealm) != 0 ||
781 	    strcmp(rep->enc_part.srealm, crealm) != 0)
782 	{
783 	    ret = KRB5KRB_AP_ERR_MODIFIED;
784 	    krb5_clear_error_message(context);
785 	    goto out;
786 	}
787     }
788 
789     /* compare nonces */
790 
791     if (nonce != (unsigned)rep->enc_part.nonce) {
792 	ret = KRB5KRB_AP_ERR_MODIFIED;
793 	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
794 	goto out;
795     }
796 
797     /* set kdc-offset */
798 
799     krb5_timeofday (context, &sec_now);
800     if (rep->enc_part.flags.initial
801 	&& (flags & EXTRACT_TICKET_TIMESYNC)
802 	&& context->kdc_sec_offset == 0
803 	&& krb5_config_get_bool (context, NULL,
804 				 "libdefaults",
805 				 "kdc_timesync",
806 				 NULL)) {
807 	context->kdc_sec_offset = rep->enc_part.authtime - sec_now;
808 	krb5_timeofday (context, &sec_now);
809     }
810 
811     /* check all times */
812 
813     if (rep->enc_part.starttime) {
814 	tmp_time = *rep->enc_part.starttime;
815     } else
816 	tmp_time = rep->enc_part.authtime;
817 
818     if (creds->times.starttime == 0
819 	&& labs(tmp_time - sec_now) > context->max_skew) {
820 	ret = KRB5KRB_AP_ERR_SKEW;
821 	krb5_set_error_message (context, ret,
822 				N_("time skew (%ld) larger than max (%ld)", ""),
823 			       labs(tmp_time - sec_now),
824 			       (long)context->max_skew);
825 	goto out;
826     }
827 
828     if (creds->times.starttime != 0
829 	&& tmp_time != creds->times.starttime) {
830 	krb5_clear_error_message (context);
831 	ret = KRB5KRB_AP_ERR_MODIFIED;
832 	goto out;
833     }
834 
835     creds->times.starttime = tmp_time;
836 
837     if (rep->enc_part.renew_till) {
838 	tmp_time = *rep->enc_part.renew_till;
839     } else
840 	tmp_time = 0;
841 
842     if (creds->times.renew_till != 0
843 	&& tmp_time > creds->times.renew_till) {
844 	krb5_clear_error_message (context);
845 	ret = KRB5KRB_AP_ERR_MODIFIED;
846 	goto out;
847     }
848 
849     creds->times.renew_till = tmp_time;
850 
851     creds->times.authtime = rep->enc_part.authtime;
852 
853     if (creds->times.endtime != 0
854 	&& rep->enc_part.endtime > creds->times.endtime) {
855 	krb5_clear_error_message (context);
856 	ret = KRB5KRB_AP_ERR_MODIFIED;
857 	goto out;
858     }
859 
860     creds->times.endtime  = rep->enc_part.endtime;
861 
862     if(rep->enc_part.caddr)
863 	krb5_copy_addresses (context, rep->enc_part.caddr, &creds->addresses);
864     else if(addrs)
865 	krb5_copy_addresses (context, addrs, &creds->addresses);
866     else {
867 	creds->addresses.len = 0;
868 	creds->addresses.val = NULL;
869     }
870     creds->flags.b = rep->enc_part.flags;
871 
872     creds->authdata.len = 0;
873     creds->authdata.val = NULL;
874 
875     /* extract ticket */
876     ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
877 		       &rep->kdc_rep.ticket, &len, ret);
878     if(ret)
879 	goto out;
880     if (creds->ticket.length != len)
881 	krb5_abortx(context, "internal error in ASN.1 encoder");
882     creds->second_ticket.length = 0;
883     creds->second_ticket.data   = NULL;
884 
885 
886 out:
887     memset (rep->enc_part.key.keyvalue.data, 0,
888 	    rep->enc_part.key.keyvalue.length);
889     return ret;
890 }
891