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      1 /*	$NetBSD: ticket.c,v 1.6 2023/06/19 21:41:45 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 - 2001 Kungliga Tekniska Hgskolan
      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     /*
    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
    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
    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
    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