/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF 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.apache.xml.security.keys.keyresolver.implementations;

import java.security.PublicKey;
import java.security.cert.X509Certificate;


import org.apache.xml.security.exceptions.XMLSecurityException;
import org.apache.xml.security.keys.content.keyvalues.RSAKeyValue;
import org.apache.xml.security.keys.keyresolver.KeyResolverSpi;
import org.apache.xml.security.keys.storage.StorageResolver;
import org.apache.xml.security.utils.Constants;
import org.apache.xml.security.utils.XMLUtils;
import org.w3c.dom.Element;

public class RSAKeyValueResolver extends KeyResolverSpi {

    /** {@link org.apache.commons.logging} logging facility */
    private static org.apache.commons.logging.Log log = 
        org.apache.commons.logging.LogFactory.getLog(RSAKeyValueResolver.class);


    /** @inheritDoc */
    public PublicKey engineLookupAndResolvePublicKey(
        Element element, String BaseURI, StorageResolver storage
    ) {
        if (log.isDebugEnabled()) {
            log.debug("Can I resolve " + element.getTagName());
        }
        if (element == null) {
            return null;
        }

        boolean isKeyValue = XMLUtils.elementIsInSignatureSpace(element, Constants._TAG_KEYVALUE);
        Element rsaKeyElement = null;
        if (isKeyValue) {                  
            rsaKeyElement = 
                XMLUtils.selectDsNode(element.getFirstChild(), Constants._TAG_RSAKEYVALUE, 0);
        } else if (XMLUtils.elementIsInSignatureSpace(element, Constants._TAG_RSAKEYVALUE)) {
            // this trick is needed to allow the RetrievalMethodResolver to eat a
            // ds:RSAKeyValue directly (without KeyValue)
            rsaKeyElement = element;		  
        }

        if (rsaKeyElement == null) {
            return null;         
        }

        try {
            RSAKeyValue rsaKeyValue = new RSAKeyValue(rsaKeyElement, BaseURI);

            return rsaKeyValue.getPublicKey();
        } catch (XMLSecurityException ex) {
            if (log.isDebugEnabled()) {
                log.debug("XMLSecurityException", ex);
            }
        }

        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
    ) {
        return null;
    }
}
