/*
* Licensed to the University Corporation for Advanced Internet Development,
* Inc. (UCAID) under one or more contributor license agreements. See the
* NOTICE file distributed with this work for additional information regarding
* copyright ownership. The UCAID licenses this file to You 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.opensaml.xml.security.keyinfo.provider;
import java.util.ArrayList;
import java.util.Collection;
import org.opensaml.xml.XMLObject;
import org.opensaml.xml.security.Criteria;
import org.opensaml.xml.security.CriteriaSet;
import org.opensaml.xml.security.SecurityException;
import org.opensaml.xml.security.credential.Credential;
import org.opensaml.xml.security.keyinfo.KeyInfoCredentialResolver;
import org.opensaml.xml.security.keyinfo.KeyInfoCriteria;
import org.opensaml.xml.security.keyinfo.KeyInfoProvider;
import org.opensaml.xml.security.keyinfo.KeyInfoResolutionContext;
import org.opensaml.xml.signature.KeyInfo;
import org.opensaml.xml.signature.KeyInfoReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Implementation of {@link KeyInfoProvider} which supports {@link KeyInfoReference}.
*
* <p>To prevent cycles, only a single reference step is permitted. Only same-document
* references are supported.</p>
*/
public class KeyInfoReferenceProvider extends AbstractKeyInfoProvider {
/** Class logger. */
private final Logger log = LoggerFactory.getLogger(KeyInfoReferenceProvider.class);
/** {@inheritDoc} */
public boolean handles(XMLObject keyInfoChild) {
return getKeyInfoReference(keyInfoChild) != null;
}
/** {@inheritDoc} */
public Collection<Credential> process(KeyInfoCredentialResolver resolver, XMLObject keyInfoChild,
CriteriaSet criteriaSet, KeyInfoResolutionContext kiContext) throws SecurityException {
KeyInfoReference ref = getKeyInfoReference(keyInfoChild);
if (ref == null) {
return null;
}
log.debug("Attempting to follow same-document KeyInfoReference");
XMLObject target = ref.resolveIDFromRoot(ref.getURI().substring(1));
if (target == null) {
log.warn("KeyInfoReference URI could not be dereferenced");
return null;
} else if (!(target instanceof KeyInfo)) {
log.warn("The product of dereferencing the KeyInfoReference was not a KeyInfo");
return null;
} else if (!((KeyInfo) target).getXMLObjects(KeyInfoReference.DEFAULT_ELEMENT_NAME).isEmpty()) {
log.warn("The dereferenced KeyInfo contained a KeyInfoReference, cannot process");
return null;
}
log.debug("Recursively processing KeyInfoReference referent");
// Copy the existing CriteriaSet, excluding the KeyInfoCriteria, which is reset to the target.
CriteriaSet newCriteria = new CriteriaSet();
newCriteria.add(new KeyInfoCriteria((KeyInfo) target));
for (Criteria crit : criteriaSet) {
if (!(crit instanceof KeyInfoCriteria)) {
newCriteria.add(crit);
}
}
// Resolve the new target and copy the results into a collection to return.
Iterable<Credential> creds = resolver.resolve(newCriteria);
if (creds != null) {
Collection<Credential> result = new ArrayList<Credential>();
for (Credential c : creds) {
result.add(c);
}
return result;
}
return null;
}
/**
* Get the KeyInfoReference from the passed XML object.
*
* @param xmlObject an XML object, presumably a {@link KeyInfoReference}
* @return the KeyInfoReference which was found, or null if none or invalid
*/
protected KeyInfoReference getKeyInfoReference(XMLObject xmlObject) {
if (xmlObject instanceof KeyInfoReference) {
KeyInfoReference ref = (KeyInfoReference) xmlObject;
String uri = ref.getURI();
if (uri != null && uri.startsWith("#")) {
return ref;
} else {
log.debug("KeyInfoReference did not contain a same-document URI reference, cannot handle");
}
}
return null;
}
}