crypto/src/java/org/apache/fulcrum/crypto/DefaultCryptoService.java

package org.apache.fulcrum.crypto;

/*
 * 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.
 */

import java.security.NoSuchAlgorithmException;
import java.util.Hashtable;

import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.thread.ThreadSafe;

/**
 * An implementation of CryptoService that uses either supplied crypto
 * Algorithms (provided in the component config xml file) or tries to get them via
 * the normal java mechanisms if this fails.
 *
 * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
 * @version $Id$
 *
 * @avalon.component name="crypto" lifestyle="singleton"
 * @avalon.service type="org.apache.fulcrum.crypto.CryptoService"
 */
public class DefaultCryptoService
    extends AbstractLogEnabled
    implements CryptoService, Configurable, Initializable, ThreadSafe
{
    //
    // SJM: removed Component and Contextualizable, Startable
    //

    /** Key Prefix for our algorithms */
    private static final String ALGORITHM = "algorithm";
    /** Default Key */
    private static final String DEFAULT_KEY = "default";
    /** Default Encryption Class */
    private static final String DEFAULT_CLASS =
      "org.apache.fulcrum.crypto.provider.JavaCrypt";
    /** Names of the registered algorithms and the wanted classes */
    private Hashtable algos = null;

    /**
     * Returns a CryptoAlgorithm Object which represents the requested
     * crypto algorithm.
     *
     * @param algo      Name of the requested algorithm
     *
     * @return An Object representing the algorithm
     *
     * @throws NoSuchAlgorithmException  Requested algorithm is not available
     *
     */
    public CryptoAlgorithm getCryptoAlgorithm( String algo )
      throws NoSuchAlgorithmException
    {
        String cryptoClass = (String) algos.get(algo);
        CryptoAlgorithm ca = null;
        if (cryptoClass == null)
        {
            cryptoClass = (String) algos.get(DEFAULT_KEY);
        }
        if (cryptoClass == null || cryptoClass.equalsIgnoreCase("none"))
        {
            throw new NoSuchAlgorithmException(
              "TurbineCryptoService: No Algorithm for " + algo + " found");
        }
        try
        {
            //@todo should be created via factory service.
            //Just trying to get something to work.
            //ca = (CryptoAlgorithm) factoryService.getInstance(cryptoClass);
            ca = (CryptoAlgorithm) Class.forName(cryptoClass).newInstance();
        }
        catch (Exception e)
        {
            throw new NoSuchAlgorithmException(
              "TurbineCryptoService: Error instantiating "
              + cryptoClass + " for " + algo);
        }
        ca.setCipher(algo);
        return ca;
    }

    // ---------------- Avalon Lifecycle Methods ---------------------

    /**
     * Avalon component lifecycle method
     */
    public void configure(Configuration conf) throws ConfigurationException
    {
        this.algos = new Hashtable();
        // Set up default (Can be overridden by default key
        // from the properties
        algos.put(DEFAULT_KEY, DEFAULT_CLASS);
        final Configuration algorithms = conf.getChild(ALGORITHM, false);
        if (algorithms != null)
        {
            Configuration[] nameVal = algorithms.getChildren();
            for (int i = 0; i < nameVal.length; i++)
            {
                String key = nameVal[i].getName();
                String val = nameVal[i].getValue();
                // getLogger.debug("Registered " + val
                //            + " for Crypto Algorithm " + key);
                algos.put(key, val);
            }
        }
    }

   /**
    * @see org.apache.avalon.framework.activity.Initializable#initialize()
    */
    public void initialize()
      throws Exception
    {
        getLogger().debug("initialize()");
    }

    /**
     * Avalon component lifecycle method
     */
    public void dispose()
    {
        algos = null;
    }

}