org.opensaml.xmlsec.encryption.support.SimpleRetrievalMethodEncryptedKeyResolver Maven / Gradle / Ivy
/*
* 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.xmlsec.encryption.support;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import net.shibboleth.utilities.java.support.logic.Constraint;
import org.opensaml.core.xml.XMLObject;
import org.opensaml.xmlsec.encryption.EncryptedData;
import org.opensaml.xmlsec.encryption.EncryptedKey;
import org.opensaml.xmlsec.signature.RetrievalMethod;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Strings;
/**
* Implementation of {@link EncryptedKeyResolver} which finds {@link EncryptedKey} elements by dereferencing
* {@link RetrievalMethod} children of the {@link org.opensaml.xmlsec.signature.KeyInfo} of the {@link EncryptedData}
* context.
*
* The RetrievalMethod must have a Type
attribute with the value of
* {@link EncryptionConstants#TYPE_ENCRYPTED_KEY}. The URI
attribute value must be a same-document
* fragment identifier (via ID attribute). Processing of transforms children of RetrievalMethod is not supported by this
* implementation.
*/
public class SimpleRetrievalMethodEncryptedKeyResolver extends AbstractEncryptedKeyResolver {
/** Class logger. */
private final Logger log = LoggerFactory.getLogger(SimpleRetrievalMethodEncryptedKeyResolver.class);
/** Constructor. */
public SimpleRetrievalMethodEncryptedKeyResolver() {
}
/**
* Constructor.
*
* @param recipients the set of recipients
*/
public SimpleRetrievalMethodEncryptedKeyResolver(@Nullable final Set recipients) {
super(recipients);
}
/**
* Constructor.
*
* @param recipient the recipient
*/
public SimpleRetrievalMethodEncryptedKeyResolver(@Nullable final String recipient) {
this(Collections.singleton(recipient));
}
/** {@inheritDoc} */
@Nonnull public Iterable resolve(@Nonnull final EncryptedData encryptedData) {
Constraint.isNotNull(encryptedData, "EncryptedData cannot be null");
final List resolvedEncKeys = new ArrayList<>();
if (encryptedData.getKeyInfo() == null) {
return resolvedEncKeys;
}
for (final RetrievalMethod rm : encryptedData.getKeyInfo().getRetrievalMethods()) {
if (!Objects.equals(rm.getType(), EncryptionConstants.TYPE_ENCRYPTED_KEY)) {
continue;
} else if (rm.getTransforms() != null) {
log.warn("EncryptedKey RetrievalMethod has transforms, cannot process");
continue;
}
final EncryptedKey encKey = dereferenceURI(rm);
if (encKey == null) {
continue;
} else if (matchRecipient(encKey.getRecipient())) {
resolvedEncKeys.add(encKey);
}
}
return resolvedEncKeys;
}
/**
* Dereference the URI attribute of the specified retrieval method into an EncryptedKey.
*
* @param rm the RetrievalMethod to process
* @return the dereferenced EncryptedKey
*/
@Nullable protected EncryptedKey dereferenceURI(@Nonnull final RetrievalMethod rm) {
final String uri = rm.getURI();
if (Strings.isNullOrEmpty(uri) || !uri.startsWith("#")) {
log.warn("EncryptedKey RetrievalMethod did not contain a same-document URI reference, cannot process");
return null;
}
final XMLObject target = rm.resolveIDFromRoot(uri.substring(1));
if (target == null) {
log.warn("EncryptedKey RetrievalMethod URI could not be dereferenced");
return null;
} else if (!(target instanceof EncryptedKey)) {
log.warn("The product of dereferencing the EncryptedKey RetrievalMethod was not an EncryptedKey");
return null;
}
return (EncryptedKey) target;
}
}