freebsd-nq/crypto/heimdal/kdc/524.c
2008-05-07 13:39:42 +00:00

401 lines
11 KiB
C

/*
* Copyright (c) 1997-2005 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 "kdc_locl.h"
RCSID("$Id: 524.c 18270 2006-10-06 17:06:30Z lha $");
#include <krb5-v4compat.h>
/*
* fetch the server from `t', returning the name in malloced memory in
* `spn' and the entry itself in `server'
*/
static krb5_error_code
fetch_server (krb5_context context,
krb5_kdc_configuration *config,
const Ticket *t,
char **spn,
hdb_entry_ex **server,
const char *from)
{
krb5_error_code ret;
krb5_principal sprinc;
ret = _krb5_principalname2krb5_principal(context, &sprinc,
t->sname, t->realm);
if (ret) {
kdc_log(context, config, 0, "_krb5_principalname2krb5_principal: %s",
krb5_get_err_text(context, ret));
return ret;
}
ret = krb5_unparse_name(context, sprinc, spn);
if (ret) {
krb5_free_principal(context, sprinc);
kdc_log(context, config, 0, "krb5_unparse_name: %s",
krb5_get_err_text(context, ret));
return ret;
}
ret = _kdc_db_fetch(context, config, sprinc, HDB_F_GET_SERVER,
NULL, server);
krb5_free_principal(context, sprinc);
if (ret) {
kdc_log(context, config, 0,
"Request to convert ticket from %s for unknown principal %s: %s",
from, *spn, krb5_get_err_text(context, ret));
if (ret == HDB_ERR_NOENTRY)
ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
return ret;
}
return 0;
}
static krb5_error_code
log_524 (krb5_context context,
krb5_kdc_configuration *config,
const EncTicketPart *et,
const char *from,
const char *spn)
{
krb5_principal client;
char *cpn;
krb5_error_code ret;
ret = _krb5_principalname2krb5_principal(context, &client,
et->cname, et->crealm);
if (ret) {
kdc_log(context, config, 0, "_krb5_principalname2krb5_principal: %s",
krb5_get_err_text (context, ret));
return ret;
}
ret = krb5_unparse_name(context, client, &cpn);
if (ret) {
krb5_free_principal(context, client);
kdc_log(context, config, 0, "krb5_unparse_name: %s",
krb5_get_err_text (context, ret));
return ret;
}
kdc_log(context, config, 1, "524-REQ %s from %s for %s", cpn, from, spn);
free(cpn);
krb5_free_principal(context, client);
return 0;
}
static krb5_error_code
verify_flags (krb5_context context,
krb5_kdc_configuration *config,
const EncTicketPart *et,
const char *spn)
{
if(et->endtime < kdc_time){
kdc_log(context, config, 0, "Ticket expired (%s)", spn);
return KRB5KRB_AP_ERR_TKT_EXPIRED;
}
if(et->flags.invalid){
kdc_log(context, config, 0, "Ticket not valid (%s)", spn);
return KRB5KRB_AP_ERR_TKT_NYV;
}
return 0;
}
/*
* set the `et->caddr' to the most appropriate address to use, where
* `addr' is the address the request was received from.
*/
static krb5_error_code
set_address (krb5_context context,
krb5_kdc_configuration *config,
EncTicketPart *et,
struct sockaddr *addr,
const char *from)
{
krb5_error_code ret;
krb5_address *v4_addr;
v4_addr = malloc (sizeof(*v4_addr));
if (v4_addr == NULL)
return ENOMEM;
ret = krb5_sockaddr2address(context, addr, v4_addr);
if(ret) {
free (v4_addr);
kdc_log(context, config, 0, "Failed to convert address (%s)", from);
return ret;
}
if (et->caddr && !krb5_address_search (context, v4_addr, et->caddr)) {
kdc_log(context, config, 0, "Incorrect network address (%s)", from);
krb5_free_address(context, v4_addr);
free (v4_addr);
return KRB5KRB_AP_ERR_BADADDR;
}
if(v4_addr->addr_type == KRB5_ADDRESS_INET) {
/* we need to collapse the addresses in the ticket to a
single address; best guess is to use the address the
connection came from */
if (et->caddr != NULL) {
free_HostAddresses(et->caddr);
} else {
et->caddr = malloc (sizeof (*et->caddr));
if (et->caddr == NULL) {
krb5_free_address(context, v4_addr);
free(v4_addr);
return ENOMEM;
}
}
et->caddr->val = v4_addr;
et->caddr->len = 1;
} else {
krb5_free_address(context, v4_addr);
free(v4_addr);
}
return 0;
}
static krb5_error_code
encrypt_v4_ticket(krb5_context context,
krb5_kdc_configuration *config,
void *buf,
size_t len,
krb5_keyblock *skey,
EncryptedData *reply)
{
krb5_crypto crypto;
krb5_error_code ret;
ret = krb5_crypto_init(context, skey, ETYPE_DES_PCBC_NONE, &crypto);
if (ret) {
free(buf);
kdc_log(context, config, 0, "krb5_crypto_init failed: %s",
krb5_get_err_text(context, ret));
return ret;
}
ret = krb5_encrypt_EncryptedData(context,
crypto,
KRB5_KU_TICKET,
buf,
len,
0,
reply);
krb5_crypto_destroy(context, crypto);
if(ret) {
kdc_log(context, config, 0, "Failed to encrypt data: %s",
krb5_get_err_text(context, ret));
return ret;
}
return 0;
}
static krb5_error_code
encode_524_response(krb5_context context,
krb5_kdc_configuration *config,
const char *spn, const EncTicketPart et,
const Ticket *t, hdb_entry_ex *server,
EncryptedData *ticket, int *kvno)
{
krb5_error_code ret;
int use_2b;
size_t len;
use_2b = krb5_config_get_bool(context, NULL, "kdc", "use_2b", spn, NULL);
if(use_2b) {
ASN1_MALLOC_ENCODE(EncryptedData,
ticket->cipher.data, ticket->cipher.length,
&t->enc_part, &len, ret);
if (ret) {
kdc_log(context, config, 0,
"Failed to encode v4 (2b) ticket (%s)", spn);
return ret;
}
ticket->etype = 0;
ticket->kvno = NULL;
*kvno = 213; /* 2b's use this magic kvno */
} else {
unsigned char buf[MAX_KTXT_LEN + 4 * 4];
Key *skey;
if (!config->enable_v4_cross_realm && strcmp (et.crealm, t->realm) != 0) {
kdc_log(context, config, 0, "524 cross-realm %s -> %s disabled", et.crealm,
t->realm);
return KRB5KDC_ERR_POLICY;
}
ret = _kdc_encode_v4_ticket(context, config,
buf + sizeof(buf) - 1, sizeof(buf),
&et, &t->sname, &len);
if(ret){
kdc_log(context, config, 0,
"Failed to encode v4 ticket (%s)", spn);
return ret;
}
ret = _kdc_get_des_key(context, server, TRUE, FALSE, &skey);
if(ret){
kdc_log(context, config, 0,
"no suitable DES key for server (%s)", spn);
return ret;
}
ret = encrypt_v4_ticket(context, config, buf + sizeof(buf) - len, len,
&skey->key, ticket);
if(ret){
kdc_log(context, config, 0,
"Failed to encrypt v4 ticket (%s)", spn);
return ret;
}
*kvno = server->entry.kvno;
}
return 0;
}
/*
* process a 5->4 request, based on `t', and received `from, addr',
* returning the reply in `reply'
*/
krb5_error_code
_kdc_do_524(krb5_context context,
krb5_kdc_configuration *config,
const Ticket *t, krb5_data *reply,
const char *from, struct sockaddr *addr)
{
krb5_error_code ret = 0;
krb5_crypto crypto;
hdb_entry_ex *server = NULL;
Key *skey;
krb5_data et_data;
EncTicketPart et;
EncryptedData ticket;
krb5_storage *sp;
char *spn = NULL;
unsigned char buf[MAX_KTXT_LEN + 4 * 4];
size_t len;
int kvno = 0;
if(!config->enable_524) {
ret = KRB5KDC_ERR_POLICY;
kdc_log(context, config, 0,
"Rejected ticket conversion request from %s", from);
goto out;
}
ret = fetch_server (context, config, t, &spn, &server, from);
if (ret) {
goto out;
}
ret = hdb_enctype2key(context, &server->entry, t->enc_part.etype, &skey);
if(ret){
kdc_log(context, config, 0,
"No suitable key found for server (%s) from %s", spn, from);
goto out;
}
ret = krb5_crypto_init(context, &skey->key, 0, &crypto);
if (ret) {
kdc_log(context, config, 0, "krb5_crypto_init failed: %s",
krb5_get_err_text(context, ret));
goto out;
}
ret = krb5_decrypt_EncryptedData (context,
crypto,
KRB5_KU_TICKET,
&t->enc_part,
&et_data);
krb5_crypto_destroy(context, crypto);
if(ret){
kdc_log(context, config, 0,
"Failed to decrypt ticket from %s for %s", from, spn);
goto out;
}
ret = krb5_decode_EncTicketPart(context, et_data.data, et_data.length,
&et, &len);
krb5_data_free(&et_data);
if(ret){
kdc_log(context, config, 0,
"Failed to decode ticket from %s for %s", from, spn);
goto out;
}
ret = log_524 (context, config, &et, from, spn);
if (ret) {
free_EncTicketPart(&et);
goto out;
}
ret = verify_flags (context, config, &et, spn);
if (ret) {
free_EncTicketPart(&et);
goto out;
}
ret = set_address (context, config, &et, addr, from);
if (ret) {
free_EncTicketPart(&et);
goto out;
}
ret = encode_524_response(context, config, spn, et, t,
server, &ticket, &kvno);
free_EncTicketPart(&et);
out:
/* make reply */
memset(buf, 0, sizeof(buf));
sp = krb5_storage_from_mem(buf, sizeof(buf));
if (sp) {
krb5_store_int32(sp, ret);
if(ret == 0){
krb5_store_int32(sp, kvno);
krb5_store_data(sp, ticket.cipher);
/* Aargh! This is coded as a KTEXT_ST. */
krb5_storage_seek(sp, MAX_KTXT_LEN - ticket.cipher.length, SEEK_CUR);
krb5_store_int32(sp, 0); /* mbz */
free_EncryptedData(&ticket);
}
ret = krb5_storage_to_data(sp, reply);
reply->length = krb5_storage_seek(sp, 0, SEEK_CUR);
krb5_storage_free(sp);
} else
krb5_data_zero(reply);
if(spn)
free(spn);
if(server)
_kdc_free_ent (context, server);
return ret;
}