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/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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,
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* See the License for the specific language governing permissions and
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package com.sun.org.apache.xml.internal.security.keys.keyresolver.implementations;
import java.security.Key;
import java.security.PublicKey;
import java.security.cert.X509Certificate;
import javax.crypto.SecretKey;
import com.sun.org.apache.xml.internal.security.encryption.EncryptedKey;
import com.sun.org.apache.xml.internal.security.encryption.XMLCipher;
import com.sun.org.apache.xml.internal.security.keys.keyresolver.KeyResolverSpi;
import com.sun.org.apache.xml.internal.security.keys.storage.StorageResolver;
import com.sun.org.apache.xml.internal.security.utils.EncryptionConstants;
import com.sun.org.apache.xml.internal.security.utils.XMLUtils;
import org.w3c.dom.Element;
/**
* The <code>EncryptedKeyResolver</code> is not a generic resolver. It can
* only be for specific instantiations, as the key being unwrapped will
* always be of a particular type and will always have been wrapped by
* another key which needs to be recursively resolved.
*
* The <code>EncryptedKeyResolver</code> can therefore only be instantiated
* with an algorithm. It can also be instantiated with a key (the KEK) or
* will search the static KeyResolvers to find the appropriate key.
*
* @author Berin Lautenbach
*/
public class EncryptedKeyResolver extends KeyResolverSpi {
/** {@link java.util.logging} logging facility */
static java.util.logging.Logger log =
java.util.logging.Logger.getLogger(
RSAKeyValueResolver.class.getName());
Key _kek;
String _algorithm;
/**
* Constructor for use when a KEK needs to be derived from a KeyInfo
* list
* @param algorithm
*/
public EncryptedKeyResolver(String algorithm) {
_kek = null;
_algorithm=algorithm;
}
/**
* Constructor used for when a KEK has been set
* @param algorithm
* @param kek
*/
public EncryptedKeyResolver(String algorithm, Key kek) {
_algorithm = algorithm;
_kek = kek;
}
/** @inheritDoc */
public PublicKey engineLookupAndResolvePublicKey(
Element element, String BaseURI, StorageResolver storage) {
return null;
}
/** @inheritDoc */
public X509Certificate engineLookupResolveX509Certificate(
Element element, String BaseURI, StorageResolver storage) {
return null;
}
/** @inheritDoc */
public javax.crypto.SecretKey engineLookupAndResolveSecretKey(
Element element, String BaseURI, StorageResolver storage) {
SecretKey key=null;
if (log.isLoggable(java.util.logging.Level.FINE))
log.log(java.util.logging.Level.FINE, "EncryptedKeyResolver - Can I resolve " + element.getTagName());
if (element == null) {
return null;
}
boolean isEncryptedKey = XMLUtils.elementIsInEncryptionSpace(element,
EncryptionConstants._TAG_ENCRYPTEDKEY);
if (isEncryptedKey) {
log.log(java.util.logging.Level.FINE, "Passed an Encrypted Key");
try {
XMLCipher cipher = XMLCipher.getInstance();
cipher.init(XMLCipher.UNWRAP_MODE, _kek);
EncryptedKey ek = cipher.loadEncryptedKey(element);
key = (SecretKey) cipher.decryptKey(ek, _algorithm);
}
catch (Exception e) {}
}
return key;
}
}