org.wildfly.security.auth.server.EvidenceDecoder Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2019 Red Hat, Inc., and individual 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.wildfly.security.auth.server;
import java.security.Principal;
import java.util.function.Function;
import org.wildfly.common.Assert;
import org.wildfly.security.evidence.Evidence;
/**
* A decoder for extracting a principal from evidence.
*
* @author Farah Juma
* @since 1.10.0
*/
@FunctionalInterface
public interface EvidenceDecoder extends Function {
/**
* Get the principal from the given evidence. If this decoder does not understand the given evidence,
* {@code null} is returned.
*
* @param evidence the evidence to decode
* @return the principal, or {@code null} if this decoder does not understand the evidence
*/
Principal getPrincipal(Evidence evidence);
default Principal apply(Evidence evidence) {
return getPrincipal(evidence);
}
/**
* Create an aggregated evidence decoder. The aggregated decoder will try each evidence decoder until one
* returns a {@code non-null} value. If all the evidence decoders return {@code null}, then {@code null}
* will be returned.
*
* @param decoders the constituent decoders
* @return the aggregated decoder
*/
static EvidenceDecoder aggregate(final EvidenceDecoder... decoders) {
Assert.checkNotNullParam("decoders", decoders);
return evidence -> {
Principal result;
for (EvidenceDecoder decoder : decoders) {
result = decoder.getPrincipal(evidence);
if (result != null) {
return result;
}
}
return null;
};
}
}