trunk/src/org/apache/ws/security/processor/EncryptedDataProcessor.java

/*
 * Copyright 2004,2005 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,
 * 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.ws.security.processor;

import org.apache.ws.security.WSConstants;
import org.apache.ws.security.WSDocInfo;
import org.apache.ws.security.WSSConfig;
import org.apache.ws.security.WSSecurityEngine;
import org.apache.ws.security.WSSecurityException;
import org.apache.ws.security.components.crypto.Crypto;
import org.apache.ws.security.util.WSSecurityUtil;
import org.apache.xml.security.encryption.XMLCipher;
import org.apache.xml.security.encryption.XMLEncryptionException;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.crypto.SecretKey;
import javax.security.auth.callback.CallbackHandler;
import javax.xml.namespace.QName;

import java.util.Vector;

/**
 * This will process incoming <code>xenc:EncryptedData</code> elements.
 * This processor will not be invoked for encrypted content referenced by a 
 * <code>xenc:ReferenceList</code>.
 *
 */
public class EncryptedDataProcessor implements Processor {

    
    private byte[] symmKey;
    
    
    public String getId() {
        return null;
    }

    public void handleToken(Element elem, Crypto crypto, Crypto decCrypto,
            CallbackHandler cb, WSDocInfo wsDocInfo, Vector returnResults,
            WSSConfig config) throws WSSecurityException {
        Element kiElem = (Element)WSSecurityUtil.findElement(elem, "KeyInfo", WSConstants.SIG_NS);
        
        
        NodeList children = kiElem.getChildNodes();
        int len = children.getLength();
        
        for(int i = 0; i < len; i++) {
            Node child = children.item(i);
            if (child.getNodeType() != Node.ELEMENT_NODE) {
                continue;
            }
            QName el = new QName(child.getNamespaceURI(), child.getLocalName());
            if(el.equals(WSSecurityEngine.ENCRYPTED_KEY)) {
                EncryptedKeyProcessor encrKeyProc = new EncryptedKeyProcessor();
                encrKeyProc.handleToken((Element)child, crypto, decCrypto, cb, wsDocInfo, returnResults, config);
                this.symmKey = encrKeyProc.getDecryptedBytes();
                break;
            }
        }
        
        String encAlgo = X509Util.getEncAlgo(elem);
        SecretKey key = WSSecurityUtil.prepareSecretKey(encAlgo, this.symmKey);
        
        // initialize Cipher ....
        XMLCipher xmlCipher = null;
        try {
            xmlCipher = XMLCipher.getInstance(encAlgo);
            xmlCipher.init(XMLCipher.DECRYPT_MODE, key);
        } catch (XMLEncryptionException e1) {
            throw new WSSecurityException(
                    WSSecurityException.UNSUPPORTED_ALGORITHM, null, null, e1);
        }
        
        Node previousSibling = elem.getPreviousSibling();

        try {
            xmlCipher.doFinal(elem.getOwnerDocument(), elem, false);
        } catch (Exception e) {
            throw new WSSecurityException(WSSecurityException.FAILED_CHECK,
                    null, null, e);
        }
        
        //GEt hold of the plain text element
        Element decryptedElem = (Element)previousSibling.getNextSibling();
        QName el = new QName(decryptedElem.getNamespaceURI(), decryptedElem
                .getLocalName());
        Processor proc = config.getProcessor(el);
        proc.handleToken((Element) decryptedElem, crypto, decCrypto, cb,
                wsDocInfo, returnResults, config);
        wsDocInfo.setProcessor(proc);
    }

}