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strongswan-ext/src/libcharon/plugins/ipseckey/ipseckey_cred.c
T

279 lines
7.2 KiB
C

/*
* Copyright (C) 2012 Reto Guadagnini
* Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include "ipseckey_cred.h"
#include "ipseckey.h"
#include <bio/bio_reader.h>
#include <daemon.h>
typedef struct private_ipseckey_cred_t private_ipseckey_cred_t;
/**
* Private data of an ipseckey_cred_t object
*/
struct private_ipseckey_cred_t {
/**
* Public part
*/
ipseckey_cred_t public;
/**
* DNS resolver
*/
resolver_t *res;
};
/**
* enumerator over certificates
*/
typedef struct {
/** implements enumerator interface */
enumerator_t public;
/** inner enumerator (enumerates IPSECKEY resource records) */
enumerator_t *inner;
/** response of the DNS resolver which contains the IPSECKEYs */
resolver_response_t *response;
/* IPSECKEYs are not valid before this point in time */
time_t notBefore;
/* IPSECKEYs are not valid after this point in time */
time_t notAfter;
/* identity to which the IPSECKEY belongs */
identification_t *identity;
} cert_enumerator_t;
METHOD(enumerator_t, cert_enumerator_enumerate, bool,
cert_enumerator_t *this, certificate_t **cert)
{
rr_t *cur_rr = NULL;
ipseckey_t *cur_ipseckey = NULL;
chunk_t pub_key;
public_key_t * key = NULL;
bool supported_ipseckey_found = FALSE;
DBG1(DBG_CFG, "ipseckey_cred: Enumerating over IPSECKEY certificates");
/* Get the next supported IPSECKEY using the inner enumerator. */
while (this->inner->enumerate(this->inner, &cur_rr) &&
!supported_ipseckey_found)
{
supported_ipseckey_found = TRUE;
cur_ipseckey = ipseckey_create_frm_rr(cur_rr);
if (!cur_ipseckey)
{
DBG1(DBG_CFG, "ipseckey_cred: Error while parsing an IPSECKEY. "
"Skipping this key");
supported_ipseckey_found = FALSE;
}
if (cur_ipseckey &&
cur_ipseckey->get_algorithm(cur_ipseckey) != IPSECKEY_ALGORITHM_RSA)
{
DBG1(DBG_CFG, "ipseckey_cred: Skipping an IPSECKEY which uses an "
"unsupported algorithm");
cur_ipseckey->destroy(cur_ipseckey);
supported_ipseckey_found = FALSE;
}
}
if (supported_ipseckey_found)
{
/*
* Wrap the key of the IPSECKEY in a certificate and return this
* certificate.
*/
pub_key = cur_ipseckey->get_public_key(cur_ipseckey);
key = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_RSA,
BUILD_BLOB_DNSKEY, pub_key,
BUILD_END);
if (!key)
{
DBG1(DBG_CFG, "ipseckey_cred: Failed to create a public key "
"from the IPSECKEY");
cur_ipseckey->destroy(cur_ipseckey);
return FALSE;
}
*cert = lib->creds->create(lib->creds, CRED_CERTIFICATE,
CERT_TRUSTED_PUBKEY,
BUILD_PUBLIC_KEY, key,
BUILD_SUBJECT, this->identity,
BUILD_NOT_BEFORE_TIME, this->notBefore,
BUILD_NOT_AFTER_TIME, this->notAfter,
BUILD_END);
return TRUE;
}
return FALSE;
}
METHOD(enumerator_t, cert_enumerator_destroy, void,
cert_enumerator_t *this)
{
this->inner->destroy(this->inner);
this->response->destroy(this->response);
free(this);
}
METHOD(credential_set_t, create_cert_enumerator, enumerator_t*,
private_ipseckey_cred_t *this, certificate_type_t cert, key_type_t key,
identification_t *id, bool trusted)
{
char *fqdn = NULL;
resolver_response_t *response = NULL;
rr_set_t *rrset = NULL;
enumerator_t *rrsig_enum = NULL;
rr_t *rrsig = NULL;
bio_reader_t *reader = NULL;
chunk_t ignore;
u_int32_t nBefore, nAfter;
cert_enumerator_t *e;
if (id && id->get_type(id) == ID_FQDN)
{
/** Query the DNS for the required IPSECKEY RRs */
if (0 >= asprintf(&fqdn, "%Y", id))
{
DBG1(DBG_CFG, "ipseckey_cred: ID is empty");
return enumerator_create_empty();
}
DBG1(DBG_CFG, "ipseckey_cred: Performing a DNS query for the IPSECKEY "
"RRs of the domain %s", fqdn);
response = this->res->query(this->res, fqdn, RR_CLASS_IN,
RR_TYPE_IPSECKEY);
if (!response)
{
DBG1(DBG_CFG, "ipseckey_cred: DNS query failed");
free(fqdn);
return enumerator_create_empty();
}
if (!response->has_data(response) ||
!response->query_name_exist(response) ||
!(response->get_security_state(response) == SECURE) )
{
DBG1(DBG_CFG, "ipseckey_cred: Unable to retrieve IPSECKEY RRs "
"for the domain %s from the DNS", fqdn);
response->destroy(response);
free(fqdn);
return enumerator_create_empty();
}
free(fqdn);
/** Determine the validity period of the retrieved IPSECKEYs
*
* We use the "Signature Inception" and "Signature Expiration" field
* of the RRSIG resource record to determine the validity period of the
* IPSECKEY RRs.
*/
rrset = response->get_rr_set(response);
rrsig_enum = rrset->create_rrsig_enumerator(rrset);
if (!rrsig_enum)
{
DBG1(DBG_CFG, "ipseckey_cred: Unable to determine the validity "
"period of the RRs, because there are "
"no RRSIGs present");
response->destroy(response);
return enumerator_create_empty();
}
/**
* Currently we use the first RRSIG of the IPSECKEY RRset
* to determine the validity period of the IPSECKEYs.
* TODO: Take multiple RRSIGs into account.
*/
if (!rrsig_enum->enumerate(rrsig_enum, &rrsig))
{
DBG1(DBG_CFG, "ipseckey_cred: Unable to determine the validity "
"period of the IPSECKEY RRs, because there are "
"no RRSIGs present");
rrsig_enum->destroy(rrsig_enum);
response->destroy(response);
return enumerator_create_empty();
}
/**
* Parse the RRSIG for its validity period.
* For the format of a RRSIG see RFC 4034.
*/
reader = bio_reader_create(rrsig->get_rdata(rrsig));
reader->read_data(reader, 8, &ignore);
reader->read_uint32(reader, &nAfter);
reader->read_uint32(reader, &nBefore);
reader->destroy(reader);
/** Create and return an iterator over the retrieved IPSECKEYs */
INIT(e,
.public = {
.enumerate = (void*)_cert_enumerator_enumerate,
.destroy = _cert_enumerator_destroy,
},
.inner = response->get_rr_set(response)->create_rr_enumerator(
response->get_rr_set(response)),
.response = response,
.notBefore = nBefore,
.notAfter = nAfter,
.identity = id,
);
return &e->public;
}
return enumerator_create_empty();
}
METHOD(ipseckey_cred_t, destroy, void,
private_ipseckey_cred_t *this)
{
this->res->destroy(this->res);
free(this);
}
/**
* Described in header.
*/
ipseckey_cred_t *ipseckey_cred_create(resolver_t *res)
{
private_ipseckey_cred_t *this;
INIT(this,
.public = {
.set = {
.create_private_enumerator = (void*)return_null,
.create_cert_enumerator = _create_cert_enumerator,
.create_shared_enumerator = (void*)return_null,
.create_cdp_enumerator = (void*)return_null,
.cache_cert = (void*)nop,
},
.destroy = _destroy,
},
.res = res,
);
return &this->public;
}