/*
* Copyright 2012-2014 Brian Campbell
*
* 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.jose4j.jwa;
import org.jose4j.lang.InvalidAlgorithmException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import static org.jose4j.jwa.AlgorithmConstraints.ConstraintType.BLACKLIST;
import static org.jose4j.jwa.AlgorithmConstraints.ConstraintType.WHITELIST;
import static org.jose4j.jws.AlgorithmIdentifiers.NONE;
/**
*/
public class AlgorithmConstraints
{
public static final AlgorithmConstraints NO_CONSTRAINTS = new AlgorithmConstraints(ConstraintType.BLACKLIST);
public static final AlgorithmConstraints DISALLOW_NONE = new AlgorithmConstraints(BLACKLIST, NONE);
public static final AlgorithmConstraints ALLOW_ONLY_NONE = new AlgorithmConstraints(WHITELIST, NONE);
public enum ConstraintType {WHITELIST, BLACKLIST}
private final ConstraintType type;
private final Set<String> algorithms;
public AlgorithmConstraints(ConstraintType type, String... algorithms)
{
if (type == null)
{
throw new NullPointerException("ConstraintType cannot be null");
}
this.type = type;
this.algorithms = new HashSet<>(Arrays.asList(algorithms));
}
public void checkConstraint(String algorithm) throws InvalidAlgorithmException
{
switch (type)
{
case WHITELIST:
if (!algorithms.contains(algorithm))
{
throw new InvalidAlgorithmException("'" +algorithm + "' is not a whitelisted algorithm.");
}
break;
case BLACKLIST:
if (algorithms.contains(algorithm))
{
throw new InvalidAlgorithmException("'" + algorithm + "' is a blacklisted algorithm.");
}
break;
}
}
}