xref: /netbsd-src/crypto/external/bsd/heimdal/dist/lib/krb5/ticket.c (revision afab4e300d3a9fb07dd8c80daf53d0feb3345706)
1 /*	$NetBSD: ticket.c,v 1.6 2023/06/19 21:41:45 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
krb5_free_ticket(krb5_context context,krb5_ticket * ticket)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
krb5_copy_ticket(krb5_context context,const krb5_ticket * from,krb5_ticket ** to)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
krb5_ticket_get_client(krb5_context context,const krb5_ticket * ticket,krb5_principal * client)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
krb5_ticket_get_server(krb5_context context,const krb5_ticket * ticket,krb5_principal * server)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
krb5_ticket_get_endtime(krb5_context context,const krb5_ticket * ticket)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
krb5_ticket_get_flags(krb5_context context,const krb5_ticket * ticket)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
find_type_in_ad(krb5_context context,int type,krb5_data * data,krb5_boolean * found,krb5_boolean failp,krb5_keyblock * sessionkey,const AuthorizationData * ad,int level)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
_krb5_get_ad(krb5_context context,const AuthorizationData * ad,krb5_keyblock * sessionkey,int type,krb5_data * data)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
krb5_ticket_get_authorization_data_type(krb5_context context,krb5_ticket * ticket,int type,krb5_data * data)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
check_server_referral(krb5_context context,krb5_kdc_rep * rep,unsigned flags,krb5_const_principal requested,krb5_const_principal returned,krb5_keyblock * key)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
check_client_anonymous(krb5_context context,krb5_kdc_rep * rep,krb5_const_principal requested,krb5_const_principal mapped,krb5_boolean is_tgs_rep)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     /*
547      * Here we must validate that the AS returned a ticket of the expected type
548      * for either a fully anonymous request, or authenticated request for an
549      * anonymous ticket.  If this is a TGS request, we're done.  Then if the
550      * 'requested' principal was anonymous, we'll check the 'mapped' principal
551      * accordingly (without enforcing the name type and perhaps the realm).
552      * Finally, if the 'requested' principal was not anonymous, well check
553      * that the 'mapped' principal has an anonymous name and type, in a
554      * non-anonymous realm.  (Should we also be checking for a realm match
555      * between the request and the mapped name in this case?)
556      */
557     if (is_tgs_rep)
558 	flags = KRB5_ANON_MATCH_ANY_NONT;
559     else if (krb5_principal_is_anonymous(context, requested,
560                                          KRB5_ANON_MATCH_ANY_NONT))
561 	flags = KRB5_ANON_MATCH_UNAUTHENTICATED | KRB5_ANON_IGNORE_NAME_TYPE;
562     else
563 	flags = KRB5_ANON_MATCH_AUTHENTICATED;
564 
565     if (!krb5_principal_is_anonymous(context, mapped, flags))
566 	return KRB5KRB_AP_ERR_MODIFIED;
567 
568     return 0;
569 }
570 
571 /*
572  * Verify returned client principal name in anonymous/referral case
573  */
574 
575 static krb5_error_code
check_client_mismatch(krb5_context context,krb5_kdc_rep * rep,krb5_const_principal requested,krb5_const_principal mapped,krb5_keyblock const * key)576 check_client_mismatch(krb5_context context,
577 		      krb5_kdc_rep *rep,
578 		      krb5_const_principal requested,
579 		      krb5_const_principal mapped,
580 		      krb5_keyblock const * key)
581 {
582     if (rep->enc_part.flags.anonymous) {
583 	if (!krb5_principal_is_anonymous(context, mapped,
584                                          KRB5_ANON_MATCH_ANY_NONT)) {
585 	    krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
586 				   N_("Anonymous ticket does not contain anonymous "
587 				      "principal", ""));
588 	    return KRB5KRB_AP_ERR_MODIFIED;
589 	}
590     } else {
591 	if (krb5_principal_compare(context, requested, mapped) == FALSE &&
592 	    !rep->enc_part.flags.enc_pa_rep) {
593 	    krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
594 				   N_("Not same client principal returned "
595 				   "as requested", ""));
596 	    return KRB5KRB_AP_ERR_MODIFIED;
597 	}
598     }
599 
600     return 0;
601 }
602 
603 
604 static krb5_error_code KRB5_CALLCONV
decrypt_tkt(krb5_context context,krb5_keyblock * key,krb5_key_usage usage,krb5_const_pointer decrypt_arg,krb5_kdc_rep * dec_rep)605 decrypt_tkt (krb5_context context,
606 	     krb5_keyblock *key,
607 	     krb5_key_usage usage,
608 	     krb5_const_pointer decrypt_arg,
609 	     krb5_kdc_rep *dec_rep)
610 {
611     krb5_error_code ret;
612     krb5_data data;
613     size_t size;
614     krb5_crypto crypto;
615 
616     ret = krb5_crypto_init(context, key, 0, &crypto);
617     if (ret)
618 	return ret;
619 
620     ret = krb5_decrypt_EncryptedData (context,
621 				      crypto,
622 				      usage,
623 				      &dec_rep->kdc_rep.enc_part,
624 				      &data);
625     krb5_crypto_destroy(context, crypto);
626 
627     if (ret)
628 	return ret;
629 
630     ret = decode_EncASRepPart(data.data,
631 			      data.length,
632 			      &dec_rep->enc_part,
633 			      &size);
634     if (ret)
635 	ret = decode_EncTGSRepPart(data.data,
636 				   data.length,
637 				   &dec_rep->enc_part,
638 				   &size);
639     krb5_data_free (&data);
640     if (ret) {
641         krb5_set_error_message(context, ret,
642 			       N_("Failed to decode encpart in ticket", ""));
643 	return ret;
644     }
645     return 0;
646 }
647 
648 KRB5_LIB_FUNCTION int KRB5_LIB_CALL
_krb5_extract_ticket(krb5_context context,krb5_kdc_rep * rep,krb5_creds * creds,krb5_keyblock * key,krb5_const_pointer keyseed,krb5_key_usage key_usage,krb5_addresses * addrs,unsigned nonce,unsigned flags,krb5_data * request,krb5_decrypt_proc decrypt_proc,krb5_const_pointer decryptarg)649 _krb5_extract_ticket(krb5_context context,
650 		     krb5_kdc_rep *rep,
651 		     krb5_creds *creds,
652 		     krb5_keyblock *key,
653 		     krb5_const_pointer keyseed,
654 		     krb5_key_usage key_usage,
655 		     krb5_addresses *addrs,
656 		     unsigned nonce,
657 		     unsigned flags,
658 		     krb5_data *request,
659 		     krb5_decrypt_proc decrypt_proc,
660 		     krb5_const_pointer decryptarg)
661 {
662     krb5_error_code ret;
663     krb5_principal tmp_principal;
664     size_t len = 0;
665     time_t tmp_time;
666     krb5_timestamp sec_now;
667 
668     /* decrypt */
669 
670     if (decrypt_proc == NULL)
671 	decrypt_proc = decrypt_tkt;
672 
673     ret = (*decrypt_proc)(context, key, key_usage, decryptarg, rep);
674     if (ret)
675 	goto out;
676 
677     if (rep->enc_part.flags.enc_pa_rep && request) {
678 	krb5_crypto crypto = NULL;
679 	Checksum cksum;
680 	PA_DATA *pa = NULL;
681 	int idx = 0;
682 
683 	_krb5_debug(context, 5, "processing enc-ap-rep");
684 
685 	if (rep->enc_part.encrypted_pa_data == NULL ||
686 	    (pa = krb5_find_padata(rep->enc_part.encrypted_pa_data->val,
687 				   rep->enc_part.encrypted_pa_data->len,
688 				   KRB5_PADATA_REQ_ENC_PA_REP,
689 				   &idx)) == NULL)
690 	{
691 	    _krb5_debug(context, 5, "KRB5_PADATA_REQ_ENC_PA_REP missing");
692 	    ret = KRB5KRB_AP_ERR_MODIFIED;
693 	    goto out;
694 	}
695 
696 	ret = krb5_crypto_init(context, key, 0, &crypto);
697 	if (ret)
698 	    goto out;
699 
700 	ret = decode_Checksum(pa->padata_value.data,
701 			      pa->padata_value.length,
702 			      &cksum, NULL);
703 	if (ret) {
704 	    krb5_crypto_destroy(context, crypto);
705 	    goto out;
706 	}
707 
708 	ret = krb5_verify_checksum(context, crypto,
709 				   KRB5_KU_AS_REQ,
710 				   request->data, request->length,
711 				   &cksum);
712 	krb5_crypto_destroy(context, crypto);
713 	free_Checksum(&cksum);
714 	_krb5_debug(context, 5, "enc-ap-rep: %svalid", (ret == 0) ? "" : "in");
715 	if (ret)
716 	    goto out;
717     }
718 
719     /* save session key */
720 
721     creds->session.keyvalue.length = 0;
722     creds->session.keyvalue.data   = NULL;
723     creds->session.keytype = rep->enc_part.key.keytype;
724     ret = krb5_data_copy (&creds->session.keyvalue,
725 			  rep->enc_part.key.keyvalue.data,
726 			  rep->enc_part.key.keyvalue.length);
727     if (ret) {
728 	krb5_clear_error_message(context);
729 	goto out;
730     }
731 
732     /* compare client and save */
733     ret = _krb5_principalname2krb5_principal(context,
734 					     &tmp_principal,
735 					     rep->kdc_rep.cname,
736 					     rep->kdc_rep.crealm);
737     if (ret)
738 	goto out;
739 
740     /* check KDC supported anonymous if it was requested */
741     if (flags & EXTRACT_TICKET_MATCH_ANON) {
742 	ret = check_client_anonymous(context,rep,
743 				     creds->client,
744 				     tmp_principal,
745 				     request == NULL); /* is TGS */
746 	if (ret) {
747 	    krb5_free_principal(context, tmp_principal);
748 	    goto out;
749 	}
750     }
751 
752     /* check client referral and save principal */
753     if((flags & EXTRACT_TICKET_ALLOW_CNAME_MISMATCH) == 0) {
754 	ret = check_client_mismatch(context, rep,
755 				    creds->client,
756 				    tmp_principal,
757 				    &creds->session);
758 	if (ret) {
759 	    krb5_free_principal (context, tmp_principal);
760 	    goto out;
761 	}
762     }
763     krb5_free_principal (context, creds->client);
764     creds->client = tmp_principal;
765 
766     /* check server referral and save principal */
767     ret = _krb5_principalname2krb5_principal (context,
768 					      &tmp_principal,
769 					      rep->enc_part.sname,
770 					      rep->enc_part.srealm);
771     if (ret)
772 	goto out;
773     if((flags & EXTRACT_TICKET_ALLOW_SERVER_MISMATCH) == 0){
774 	ret = check_server_referral(context,
775 				    rep,
776 				    flags,
777 				    creds->server,
778 				    tmp_principal,
779 				    &creds->session);
780 	if (ret) {
781 	    krb5_free_principal (context, tmp_principal);
782 	    goto out;
783 	}
784     }
785     krb5_free_principal(context, creds->server);
786     creds->server = tmp_principal;
787 
788     /* verify names */
789     if(flags & EXTRACT_TICKET_MATCH_REALM){
790 	const char *srealm = krb5_principal_get_realm(context, creds->server);
791 	const char *crealm = krb5_principal_get_realm(context, creds->client);
792 
793 	if (strcmp(rep->enc_part.srealm, srealm) != 0 ||
794 	    strcmp(rep->enc_part.srealm, crealm) != 0)
795 	{
796 	    ret = KRB5KRB_AP_ERR_MODIFIED;
797 	    krb5_clear_error_message(context);
798 	    goto out;
799 	}
800     }
801 
802     /* compare nonces */
803 
804     if (nonce != (unsigned)rep->enc_part.nonce) {
805 	ret = KRB5KRB_AP_ERR_MODIFIED;
806 	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
807 	goto out;
808     }
809 
810     /* set kdc-offset */
811 
812     krb5_timeofday (context, &sec_now);
813     if (rep->enc_part.flags.initial
814 	&& (flags & EXTRACT_TICKET_TIMESYNC)
815 	&& context->kdc_sec_offset == 0
816 	&& krb5_config_get_bool (context, NULL,
817 				 "libdefaults",
818 				 "kdc_timesync",
819 				 NULL)) {
820 	context->kdc_sec_offset = rep->enc_part.authtime - sec_now;
821 	krb5_timeofday (context, &sec_now);
822     }
823 
824     /* check all times */
825 
826     if (rep->enc_part.starttime) {
827 	tmp_time = *rep->enc_part.starttime;
828     } else
829 	tmp_time = rep->enc_part.authtime;
830 
831     if (creds->times.starttime == 0
832 	&& labs(tmp_time - sec_now) > context->max_skew) {
833 	ret = KRB5KRB_AP_ERR_SKEW;
834 	krb5_set_error_message (context, ret,
835 				N_("time skew (%ld) larger than max (%ld)", ""),
836 			       labs(tmp_time - sec_now),
837 			       (long)context->max_skew);
838 	goto out;
839     }
840 
841     if (creds->times.starttime != 0
842 	&& tmp_time != creds->times.starttime) {
843 	krb5_clear_error_message (context);
844 	ret = KRB5KRB_AP_ERR_MODIFIED;
845 	goto out;
846     }
847 
848     creds->times.starttime = tmp_time;
849 
850     if (rep->enc_part.renew_till) {
851 	tmp_time = *rep->enc_part.renew_till;
852     } else
853 	tmp_time = 0;
854 
855     if (creds->times.renew_till != 0
856 	&& tmp_time > creds->times.renew_till) {
857 	krb5_clear_error_message (context);
858 	ret = KRB5KRB_AP_ERR_MODIFIED;
859 	goto out;
860     }
861 
862     creds->times.renew_till = tmp_time;
863 
864     creds->times.authtime = rep->enc_part.authtime;
865 
866     if (creds->times.endtime != 0
867 	&& rep->enc_part.endtime > creds->times.endtime) {
868 	krb5_clear_error_message (context);
869 	ret = KRB5KRB_AP_ERR_MODIFIED;
870 	goto out;
871     }
872 
873     creds->times.endtime  = rep->enc_part.endtime;
874 
875     if(rep->enc_part.caddr)
876 	krb5_copy_addresses (context, rep->enc_part.caddr, &creds->addresses);
877     else if(addrs)
878 	krb5_copy_addresses (context, addrs, &creds->addresses);
879     else {
880 	creds->addresses.len = 0;
881 	creds->addresses.val = NULL;
882     }
883     creds->flags.b = rep->enc_part.flags;
884 
885     creds->authdata.len = 0;
886     creds->authdata.val = NULL;
887 
888     /* extract ticket */
889     ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
890 		       &rep->kdc_rep.ticket, &len, ret);
891     if(ret)
892 	goto out;
893     if (creds->ticket.length != len)
894 	krb5_abortx(context, "internal error in ASN.1 encoder");
895     creds->second_ticket.length = 0;
896     creds->second_ticket.data   = NULL;
897 
898 
899 out:
900     memset (rep->enc_part.key.keyvalue.data, 0,
901 	    rep->enc_part.key.keyvalue.length);
902     return ret;
903 }
904