NetBSD-5.0.2/crypto/dist/heimdal/kdc/kx509.c
/*
* Copyright (c) 2006 - 2007 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"
#include <hex.h>
#include <rfc2459_asn1.h>
#include <hx509.h>
__RCSID("$Heimdal: kx509.c 21607 2007-07-17 07:04:52Z lha $"
"$NetBSD: kx509.c,v 1.1 2008/03/22 08:37:03 mlelstv Exp $");
/*
*
*/
krb5_error_code
_kdc_try_kx509_request(void *ptr, size_t len, Kx509Request *req, size_t *size)
{
if (len < 4)
return -1;
if (memcmp("\x00\x00\x02\x00", ptr, 4) != 0)
return -1;
return decode_Kx509Request(((unsigned char *)ptr) + 4, len - 4, req, size);
}
/*
*
*/
static const unsigned char version_2_0[4] = {0 , 0, 2, 0};
static krb5_error_code
verify_req_hash(krb5_context context,
const Kx509Request *req,
krb5_keyblock *key)
{
unsigned char digest[SHA_DIGEST_LENGTH];
HMAC_CTX ctx;
if (req->pk_hash.length != sizeof(digest)) {
krb5_set_error_string(context, "pk-hash have wrong length: %lu",
(unsigned long)req->pk_hash.length);
return KRB5KDC_ERR_PREAUTH_FAILED;
}
HMAC_CTX_init(&ctx);
HMAC_Init_ex(&ctx,
key->keyvalue.data, key->keyvalue.length,
EVP_sha1(), NULL);
if (sizeof(digest) != HMAC_size(&ctx))
krb5_abortx(context, "runtime error, hmac buffer wrong size in kx509");
HMAC_Update(&ctx, version_2_0, sizeof(version_2_0));
HMAC_Update(&ctx, req->pk_key.data, req->pk_key.length);
HMAC_Final(&ctx, digest, 0);
HMAC_CTX_cleanup(&ctx);
if (memcmp(req->pk_hash.data, digest, sizeof(digest)) != 0) {
krb5_set_error_string(context, "pk-hash is not correct");
return KRB5KDC_ERR_PREAUTH_FAILED;
}
return 0;
}
static krb5_error_code
calculate_reply_hash(krb5_context context,
krb5_keyblock *key,
Kx509Response *rep)
{
HMAC_CTX ctx;
HMAC_CTX_init(&ctx);
HMAC_Init_ex(&ctx,
key->keyvalue.data, key->keyvalue.length,
EVP_sha1(), NULL);
rep->hash->length = HMAC_size(&ctx);
rep->hash->data = malloc(rep->hash->length);
if (rep->hash->data == NULL) {
HMAC_CTX_cleanup(&ctx);
krb5_set_error_string(context, "out of memory");
return ENOMEM;
}
HMAC_Update(&ctx, version_2_0, sizeof(version_2_0));
if (rep->error_code) {
int32_t t = *rep->error_code;
do {
unsigned char p = (t & 0xff);
HMAC_Update(&ctx, &p, 1);
t >>= 8;
} while (t);
}
if (rep->certificate)
HMAC_Update(&ctx, rep->certificate->data, rep->certificate->length);
if (rep->e_text)
HMAC_Update(&ctx, (unsigned char *)*rep->e_text, strlen(*rep->e_text));
HMAC_Final(&ctx, rep->hash->data, 0);
HMAC_CTX_cleanup(&ctx);
return 0;
}
/*
* Build a certifate for `principal´ that will expire at `endtime´.
*/
static krb5_error_code
build_certificate(krb5_context context,
krb5_kdc_configuration *config,
const krb5_data *key,
time_t endtime,
krb5_principal principal,
krb5_data *certificate)
{
hx509_context hxctx = NULL;
hx509_ca_tbs tbs = NULL;
hx509_env env = NULL;
hx509_cert cert = NULL;
hx509_cert signer = NULL;
int ret;
if (krb5_principal_get_comp_string(context, principal, 1) != NULL) {
kdc_log(context, config, 0, "Principal is not a user");
return EINVAL;
}
ret = hx509_context_init(&hxctx);
if (ret)
goto out;
ret = hx509_env_init(hxctx, &env);
if (ret)
goto out;
ret = hx509_env_add(hxctx, env, "principal-name",
krb5_principal_get_comp_string(context, principal, 0));
if (ret)
goto out;
{
hx509_certs certs;
hx509_query *q;
ret = hx509_certs_init(hxctx, config->kx509_ca, 0,
NULL, &certs);
if (ret) {
kdc_log(context, config, 0, "Failed to load CA %s",
config->kx509_ca);
goto out;
}
ret = hx509_query_alloc(hxctx, &q);
if (ret) {
hx509_certs_free(&certs);
goto out;
}
hx509_query_match_option(q, HX509_QUERY_OPTION_PRIVATE_KEY);
hx509_query_match_option(q, HX509_QUERY_OPTION_KU_KEYCERTSIGN);
ret = hx509_certs_find(hxctx, certs, q, &signer);
hx509_query_free(hxctx, q);
hx509_certs_free(&certs);
if (ret) {
kdc_log(context, config, 0, "Failed to find a CA in %s",
config->kx509_ca);
goto out;
}
}
ret = hx509_ca_tbs_init(hxctx, &tbs);
if (ret)
goto out;
{
SubjectPublicKeyInfo spki;
heim_any any;
memset(&spki, 0, sizeof(spki));
spki.subjectPublicKey.data = key->data;
spki.subjectPublicKey.length = key->length * 8;
ret = der_copy_oid(oid_id_pkcs1_rsaEncryption(),
&spki.algorithm.algorithm);
any.data = "\x05\x00";
any.length = 2;
spki.algorithm.parameters = &any;
ret = hx509_ca_tbs_set_spki(hxctx, tbs, &spki);
der_free_oid(&spki.algorithm.algorithm);
if (ret)
goto out;
}
{
hx509_certs certs;
hx509_cert template;
ret = hx509_certs_init(hxctx, config->kx509_template, 0,
NULL, &certs);
if (ret) {
kdc_log(context, config, 0, "Failed to load template %s",
config->kx509_template);
goto out;
}
ret = hx509_get_one_cert(hxctx, certs, &template);
hx509_certs_free(&certs);
if (ret) {
kdc_log(context, config, 0, "Failed to find template in %s",
config->kx509_template);
goto out;
}
ret = hx509_ca_tbs_set_template(hxctx, tbs,
HX509_CA_TEMPLATE_SUBJECT|
HX509_CA_TEMPLATE_KU|
HX509_CA_TEMPLATE_EKU,
template);
hx509_cert_free(template);
if (ret)
goto out;
}
hx509_ca_tbs_set_notAfter(hxctx, tbs, endtime);
hx509_ca_tbs_subject_expand(hxctx, tbs, env);
hx509_env_free(&env);
ret = hx509_ca_sign(hxctx, tbs, signer, &cert);
hx509_cert_free(signer);
if (ret)
goto out;
hx509_ca_tbs_free(&tbs);
ret = hx509_cert_binary(hxctx, cert, certificate);
hx509_cert_free(cert);
if (ret)
goto out;
hx509_context_free(&hxctx);
return 0;
out:
if (env)
hx509_env_free(&env);
if (tbs)
hx509_ca_tbs_free(&tbs);
if (signer)
hx509_cert_free(signer);
if (hxctx)
hx509_context_free(&hxctx);
krb5_set_error_string(context, "cert creation failed");
return ret;
}
/*
*
*/
krb5_error_code
_kdc_do_kx509(krb5_context context,
krb5_kdc_configuration *config,
const Kx509Request *req, krb5_data *reply,
const char *from, struct sockaddr *addr)
{
krb5_error_code ret;
krb5_ticket *ticket = NULL;
krb5_flags ap_req_options;
krb5_auth_context ac = NULL;
krb5_keytab id = NULL;
krb5_principal sprincipal = NULL, cprincipal = NULL;
char *cname = NULL;
Kx509Response rep;
size_t size;
krb5_keyblock *key = NULL;
krb5_data_zero(reply);
memset(&rep, 0, sizeof(rep));
if(!config->enable_kx509) {
kdc_log(context, config, 0,
"Rejected kx509 request (disabled) from %s", from);
return KRB5KDC_ERR_POLICY;
}
kdc_log(context, config, 0, "Kx509 request from %s", from);
ret = krb5_kt_resolve(context, "HDB:", &id);
if (ret) {
kdc_log(context, config, 0, "Can't open database for digest");
goto out;
}
ret = krb5_rd_req(context,
&ac,
&req->authenticator,
NULL,
id,
&ap_req_options,
&ticket);
if (ret)
goto out;
ret = krb5_ticket_get_client(context, ticket, &cprincipal);
if (ret)
goto out;
ret = krb5_unparse_name(context, cprincipal, &cname);
if (ret)
goto out;
/* verify server principal */
ret = krb5_sname_to_principal(context, NULL, "kca_service",
KRB5_NT_UNKNOWN, &sprincipal);
if (ret)
goto out;
{
krb5_principal principal = NULL;
ret = krb5_ticket_get_server(context, ticket, &principal);
if (ret)
goto out;
ret = krb5_principal_compare(context, sprincipal, principal);
krb5_free_principal(context, principal);
if (ret != TRUE) {
ret = KRB5KDC_ERR_SERVER_NOMATCH;
krb5_set_error_string(context,
"User %s used wrong Kx509 service principal",
cname);
goto out;
}
}
ret = krb5_auth_con_getkey(context, ac, &key);
if (ret || key == NULL) {
krb5_set_error_string(context, "Kx509 can't get session key");
goto out;
}
ret = verify_req_hash(context, req, key);
if (ret)
goto out;
/* Verify that the key is encoded RSA key */
{
RSAPublicKey key;
size_t size;
ret = decode_RSAPublicKey(req->pk_key.data, req->pk_key.length,
&key, &size);
if (ret)
goto out;
free_RSAPublicKey(&key);
if (size != req->pk_key.length)
;
}
ALLOC(rep.certificate);
if (rep.certificate == NULL)
goto out;
krb5_data_zero(rep.certificate);
ALLOC(rep.hash);
if (rep.hash == NULL)
goto out;
krb5_data_zero(rep.hash);
ret = build_certificate(context, config, &req->pk_key,
krb5_ticket_get_endtime(context, ticket),
cprincipal, rep.certificate);
if (ret)
goto out;
ret = calculate_reply_hash(context, key, &rep);
if (ret)
goto out;
/*
* Encode reply, [ version | Kx509Response ]
*/
{
krb5_data data;
ASN1_MALLOC_ENCODE(Kx509Response, data.data, data.length, &rep,
&size, ret);
if (ret) {
krb5_set_error_string(context, "Failed to encode kx509 reply");
goto out;
}
if (size != data.length)
krb5_abortx(context, "ASN1 internal error");
ret = krb5_data_alloc(reply, data.length + sizeof(version_2_0));
if (ret) {
free(data.data);
goto out;
}
memcpy(reply->data, version_2_0, sizeof(version_2_0));
memcpy(((unsigned char *)reply->data) + sizeof(version_2_0),
data.data, data.length);
free(data.data);
}
kdc_log(context, config, 0, "Successful Kx509 request for %s", cname);
out:
if (ac)
krb5_auth_con_free(context, ac);
if (ret)
krb5_warn(context, ret, "Kx509 request from %s failed", from);
if (ticket)
krb5_free_ticket(context, ticket);
if (id)
krb5_kt_close(context, id);
if (sprincipal)
krb5_free_principal(context, sprincipal);
if (cprincipal)
krb5_free_principal(context, cprincipal);
if (key)
krb5_free_keyblock (context, key);
if (cname)
free(cname);
free_Kx509Response(&rep);
return 0;
}