/*
* Copyright 2016 Analytical Graphics, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.keycloak.common.util;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.DERIA5String;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.x509.CRLDistPoint;
import org.bouncycastle.asn1.x509.DistributionPoint;
import org.bouncycastle.asn1.x509.DistributionPointName;
import org.bouncycastle.asn1.x509.GeneralName;
import org.bouncycastle.asn1.x509.GeneralNames;
/**
* @author <a href="mailto:brat000012001@gmail.com">Peter Nalyvayko</a>
* @version $Revision: 1 $
* @since 10/31/2016
*/
public final class CRLUtils {
static {
BouncyIntegration.init();
}
private static final String CRL_DISTRIBUTION_POINTS_OID = "2.5.29.31";
/**
* Retrieves a list of CRL distribution points from CRLDP v3 certificate extension
* See <a href="www.nakov.com/blog/2009/12/01/x509-certificate-validation-in-java-build-and-verify-cchain-and-verify-clr-with-bouncy-castle/">CRL validation</a>
* @param cert
* @return
* @throws IOException
*/
public static List<String> getCRLDistributionPoints(X509Certificate cert) throws IOException {
byte[] data = cert.getExtensionValue(CRL_DISTRIBUTION_POINTS_OID);
if (data == null) {
return Collections.emptyList();
}
List<String> distributionPointUrls = new LinkedList<>();
DEROctetString octetString;
try (ASN1InputStream crldpExtensionInputStream = new ASN1InputStream(new ByteArrayInputStream(data))) {
octetString = (DEROctetString)crldpExtensionInputStream.readObject();
}
byte[] octets = octetString.getOctets();
CRLDistPoint crlDP;
try (ASN1InputStream crldpInputStream = new ASN1InputStream(new ByteArrayInputStream(octets))) {
crlDP = CRLDistPoint.getInstance(crldpInputStream.readObject());
}
for (DistributionPoint dp : crlDP.getDistributionPoints()) {
DistributionPointName dpn = dp.getDistributionPoint();
if (dpn != null && dpn.getType() == DistributionPointName.FULL_NAME) {
GeneralName[] names = GeneralNames.getInstance(dpn.getName()).getNames();
for (GeneralName gn : names) {
if (gn.getTagNo() == GeneralName.uniformResourceIdentifier) {
String url = DERIA5String.getInstance(gn.getName()).getString();
distributionPointUrls.add(url);
}
}
}
}
return distributionPointUrls;
}
}