OpenBSD-4.6/kerberosV/src/lib/krb5/rd_req.c
/*
* Copyright (c) 1997 - 2001, 2003 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <krb5_locl.h>
RCSID("$KTH: rd_req.c,v 1.57.4.1 2006/02/03 14:38:02 lha Exp $");
static krb5_error_code
decrypt_tkt_enc_part (krb5_context context,
krb5_keyblock *key,
EncryptedData *enc_part,
EncTicketPart *decr_part)
{
krb5_error_code ret;
krb5_data plain;
size_t len;
krb5_crypto crypto;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret)
return ret;
ret = krb5_decrypt_EncryptedData (context,
crypto,
KRB5_KU_TICKET,
enc_part,
&plain);
krb5_crypto_destroy(context, crypto);
if (ret)
return ret;
ret = krb5_decode_EncTicketPart(context, plain.data, plain.length,
decr_part, &len);
krb5_data_free (&plain);
return ret;
}
static krb5_error_code
decrypt_authenticator (krb5_context context,
EncryptionKey *key,
EncryptedData *enc_part,
Authenticator *authenticator,
krb5_key_usage usage)
{
krb5_error_code ret;
krb5_data plain;
size_t len;
krb5_crypto crypto;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret)
return ret;
ret = krb5_decrypt_EncryptedData (context,
crypto,
usage /* KRB5_KU_AP_REQ_AUTH */,
enc_part,
&plain);
/* for backwards compatibility, also try the old usage */
if (ret && usage == KRB5_KU_TGS_REQ_AUTH)
ret = krb5_decrypt_EncryptedData (context,
crypto,
KRB5_KU_AP_REQ_AUTH,
enc_part,
&plain);
krb5_crypto_destroy(context, crypto);
if (ret)
return ret;
ret = krb5_decode_Authenticator(context, plain.data, plain.length,
authenticator, &len);
krb5_data_free (&plain);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_decode_ap_req(krb5_context context,
const krb5_data *inbuf,
krb5_ap_req *ap_req)
{
krb5_error_code ret;
size_t len;
ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len);
if (ret)
return ret;
if (ap_req->pvno != 5){
free_AP_REQ(ap_req);
krb5_clear_error_string (context);
return KRB5KRB_AP_ERR_BADVERSION;
}
if (ap_req->msg_type != krb_ap_req){
free_AP_REQ(ap_req);
krb5_clear_error_string (context);
return KRB5KRB_AP_ERR_MSG_TYPE;
}
if (ap_req->ticket.tkt_vno != 5){
free_AP_REQ(ap_req);
krb5_clear_error_string (context);
return KRB5KRB_AP_ERR_BADVERSION;
}
return 0;
}
static krb5_error_code
check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc)
{
char **realms;
int num_realms;
krb5_error_code ret;
if(enc->transited.tr_type != DOMAIN_X500_COMPRESS)
return KRB5KDC_ERR_TRTYPE_NOSUPP;
if(enc->transited.contents.length == 0)
return 0;
ret = krb5_domain_x500_decode(context, enc->transited.contents,
&realms, &num_realms,
enc->crealm,
ticket->realm);
if(ret)
return ret;
ret = krb5_check_transited(context, enc->crealm,
ticket->realm,
realms, num_realms, NULL);
free(realms);
return ret;
}
static krb5_error_code
find_etypelist(krb5_context context,
krb5_auth_context auth_context,
EtypeList *etypes)
{
krb5_error_code ret;
krb5_authdata *ad;
krb5_authdata adIfRelevant;
unsigned i;
adIfRelevant.len = 0;
etypes->len = 0;
etypes->val = NULL;
ad = auth_context->authenticator->authorization_data;
if (ad == NULL)
return 0;
for (i = 0; i < ad->len; i++) {
if (ad->val[i].ad_type == KRB5_AUTHDATA_IF_RELEVANT) {
ret = decode_AD_IF_RELEVANT(ad->val[i].ad_data.data,
ad->val[i].ad_data.length,
&adIfRelevant,
NULL);
if (ret)
return ret;
if (adIfRelevant.len == 1 &&
adIfRelevant.val[0].ad_type ==
KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION) {
break;
}
free_AD_IF_RELEVANT(&adIfRelevant);
adIfRelevant.len = 0;
}
}
if (adIfRelevant.len == 0)
return 0;
ret = decode_EtypeList(adIfRelevant.val[0].ad_data.data,
adIfRelevant.val[0].ad_data.length,
etypes,
NULL);
free_AD_IF_RELEVANT(&adIfRelevant);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_decrypt_ticket(krb5_context context,
Ticket *ticket,
krb5_keyblock *key,
EncTicketPart *out,
krb5_flags flags)
{
EncTicketPart t;
krb5_error_code ret;
ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
if (ret)
return ret;
{
krb5_timestamp now;
time_t start = t.authtime;
krb5_timeofday (context, &now);
if(t.starttime)
start = *t.starttime;
if(start - now > context->max_skew
|| (t.flags.invalid
&& !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
free_EncTicketPart(&t);
krb5_clear_error_string (context);
return KRB5KRB_AP_ERR_TKT_NYV;
}
if(now - t.endtime > context->max_skew) {
free_EncTicketPart(&t);
krb5_clear_error_string (context);
return KRB5KRB_AP_ERR_TKT_EXPIRED;
}
if(!t.flags.transited_policy_checked) {
ret = check_transited(context, ticket, &t);
if(ret) {
free_EncTicketPart(&t);
return ret;
}
}
}
if(out)
*out = t;
else
free_EncTicketPart(&t);
return 0;
}
krb5_error_code KRB5_LIB_FUNCTION
krb5_verify_authenticator_checksum(krb5_context context,
krb5_auth_context ac,
void *data,
size_t len)
{
krb5_error_code ret;
krb5_keyblock *key;
krb5_authenticator authenticator;
krb5_crypto crypto;
ret = krb5_auth_con_getauthenticator (context,
ac,
&authenticator);
if(ret)
return ret;
if(authenticator->cksum == NULL) {
krb5_free_authenticator(context, &authenticator);
return -17;
}
ret = krb5_auth_con_getkey(context, ac, &key);
if(ret) {
krb5_free_authenticator(context, &authenticator);
return ret;
}
ret = krb5_crypto_init(context, key, 0, &crypto);
if(ret)
goto out;
ret = krb5_verify_checksum (context,
crypto,
KRB5_KU_AP_REQ_AUTH_CKSUM,
data,
len,
authenticator->cksum);
krb5_crypto_destroy(context, crypto);
out:
krb5_free_authenticator(context, &authenticator);
krb5_free_keyblock(context, key);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
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)
{
return krb5_verify_ap_req2 (context,
auth_context,
ap_req,
server,
keyblock,
flags,
ap_req_options,
ticket,
KRB5_KU_AP_REQ_AUTH);
}
krb5_error_code KRB5_LIB_FUNCTION
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)
{
krb5_ticket *t;
krb5_auth_context ac;
krb5_error_code ret;
EtypeList etypes;
if (auth_context && *auth_context) {
ac = *auth_context;
} else {
ret = krb5_auth_con_init (context, &ac);
if (ret)
return ret;
}
t = malloc(sizeof(*t));
if (t == NULL) {
ret = ENOMEM;
krb5_clear_error_string (context);
goto out;
}
memset(t, 0, sizeof(*t));
if (ap_req->ap_options.use_session_key && ac->keyblock){
ret = krb5_decrypt_ticket(context, &ap_req->ticket,
ac->keyblock,
&t->ticket,
flags);
krb5_free_keyblock(context, ac->keyblock);
ac->keyblock = NULL;
}else
ret = krb5_decrypt_ticket(context, &ap_req->ticket,
keyblock,
&t->ticket,
flags);
if(ret)
goto out;
_krb5_principalname2krb5_principal(&t->server, ap_req->ticket.sname,
ap_req->ticket.realm);
_krb5_principalname2krb5_principal(&t->client, t->ticket.cname,
t->ticket.crealm);
/* save key */
krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
ret = decrypt_authenticator (context,
&t->ticket.key,
&ap_req->authenticator,
ac->authenticator,
usage);
if (ret)
goto out;
{
krb5_principal p1, p2;
krb5_boolean res;
_krb5_principalname2krb5_principal(&p1,
ac->authenticator->cname,
ac->authenticator->crealm);
_krb5_principalname2krb5_principal(&p2,
t->ticket.cname,
t->ticket.crealm);
res = krb5_principal_compare (context, p1, p2);
krb5_free_principal (context, p1);
krb5_free_principal (context, p2);
if (!res) {
ret = KRB5KRB_AP_ERR_BADMATCH;
krb5_clear_error_string (context);
goto out;
}
}
/* check addresses */
if (t->ticket.caddr
&& ac->remote_address
&& !krb5_address_search (context,
ac->remote_address,
t->ticket.caddr)) {
ret = KRB5KRB_AP_ERR_BADADDR;
krb5_clear_error_string (context);
goto out;
}
/* check timestamp in authenticator */
{
krb5_timestamp now;
krb5_timeofday (context, &now);
if (abs(ac->authenticator->ctime - now) > context->max_skew) {
ret = KRB5KRB_AP_ERR_SKEW;
krb5_clear_error_string (context);
goto out;
}
}
if (ac->authenticator->seq_number)
krb5_auth_con_setremoteseqnumber(context, ac,
*ac->authenticator->seq_number);
/* XXX - Xor sequence numbers */
if (ac->authenticator->subkey) {
ret = krb5_auth_con_setremotesubkey(context, ac,
ac->authenticator->subkey);
if (ret)
goto out;
}
ret = find_etypelist(context, ac, &etypes);
if (ret)
goto out;
ac->keytype = ETYPE_NULL;
if (etypes.val) {
int i;
for (i = 0; i < etypes.len; i++) {
if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
ac->keytype = etypes.val[i];
break;
}
}
}
if (ap_req_options) {
*ap_req_options = 0;
if (ac->keytype != ETYPE_NULL)
*ap_req_options |= AP_OPTS_USE_SUBKEY;
if (ap_req->ap_options.use_session_key)
*ap_req_options |= AP_OPTS_USE_SESSION_KEY;
if (ap_req->ap_options.mutual_required)
*ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
}
if(ticket)
*ticket = t;
else
krb5_free_ticket (context, t);
if (auth_context) {
if (*auth_context == NULL)
*auth_context = ac;
} else
krb5_auth_con_free (context, ac);
free_EtypeList(&etypes);
return 0;
out:
if (t)
krb5_free_ticket (context, t);
if (auth_context == NULL || *auth_context == NULL)
krb5_auth_con_free (context, ac);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
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)
{
krb5_error_code ret;
krb5_ap_req ap_req;
if (*auth_context == NULL) {
ret = krb5_auth_con_init(context, auth_context);
if (ret)
return ret;
}
ret = krb5_decode_ap_req(context, inbuf, &ap_req);
if(ret)
return ret;
ret = krb5_verify_ap_req(context,
auth_context,
&ap_req,
server,
keyblock,
0,
ap_req_options,
ticket);
free_AP_REQ(&ap_req);
return ret;
}
static krb5_error_code
get_key_from_keytab(krb5_context context,
krb5_auth_context *auth_context,
krb5_ap_req *ap_req,
krb5_const_principal server,
krb5_keytab keytab,
krb5_keyblock **out_key)
{
krb5_keytab_entry entry;
krb5_error_code ret;
int kvno;
krb5_keytab real_keytab;
if(keytab == NULL)
krb5_kt_default(context, &real_keytab);
else
real_keytab = keytab;
if (ap_req->ticket.enc_part.kvno)
kvno = *ap_req->ticket.enc_part.kvno;
else
kvno = 0;
ret = krb5_kt_get_entry (context,
real_keytab,
server,
kvno,
ap_req->ticket.enc_part.etype,
&entry);
if(ret)
goto out;
ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
krb5_kt_free_entry (context, &entry);
out:
if(keytab == NULL)
krb5_kt_close(context, real_keytab);
return ret;
}
krb5_error_code KRB5_LIB_FUNCTION
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)
{
krb5_error_code ret;
krb5_ap_req ap_req;
krb5_keyblock *keyblock = NULL;
krb5_principal service = NULL;
if (*auth_context == NULL) {
ret = krb5_auth_con_init(context, auth_context);
if (ret)
return ret;
}
ret = krb5_decode_ap_req(context, inbuf, &ap_req);
if(ret)
return ret;
if(server == NULL){
_krb5_principalname2krb5_principal(&service,
ap_req.ticket.sname,
ap_req.ticket.realm);
server = service;
}
if (ap_req.ap_options.use_session_key &&
(*auth_context)->keyblock == NULL) {
krb5_set_error_string(context, "krb5_rd_req: user to user auth "
"without session key given");
ret = KRB5KRB_AP_ERR_NOKEY;
goto out;
}
if((*auth_context)->keyblock == NULL){
ret = get_key_from_keytab(context,
auth_context,
&ap_req,
server,
keytab,
&keyblock);
if(ret)
goto out;
} else {
ret = krb5_copy_keyblock(context,
(*auth_context)->keyblock,
&keyblock);
if (ret)
goto out;
}
ret = krb5_verify_ap_req(context,
auth_context,
&ap_req,
server,
keyblock,
0,
ap_req_options,
ticket);
krb5_free_keyblock(context, keyblock);
out:
free_AP_REQ(&ap_req);
if(service)
krb5_free_principal(context, service);
return ret;
}