/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "<WebSig>" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 2001, Institute for
 * Data Communications Systems, <http://www.nue.et-inf.uni-siegen.de/>.
 * The development of this software was partly funded by the European
 * Commission in the <WebSig> project in the ISIS Programme.
 * For more information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xml.security.keys.keyresolver;



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

import javax.crypto.SecretKey;

import org.apache.xml.security.keys.storage.StorageResolver;
import org.w3c.dom.Element;


/**
 * This class is abstract class for a child KeyInfo Elemnet.
 *
 * If you want the your KeyResolver, at firstly you must extand this class, and register
 * as following in config.xml
 * <PRE>
 *  &lt;KeyResolver URI="http://www.w3.org/2000/09/xmldsig#KeyValue"
 *   JAVACLASS="MyPackage.MyKeyValueImpl"//gt;
 * </PRE>
 *
 * @author $Author$
 * @version $Revision$
 */
public abstract class KeyResolverSpi {

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

   /**
    * This method helps the {@link ResourceResolver} to decide whether a
    * {@link ResourceResolverSpi} is able to perform the requested action.
    *
    * @param element
    * @param BaseURI
    * @param storage
    *
    */
   abstract public boolean engineCanResolve(Element element, String BaseURI,
                                            StorageResolver storage);

   /**
    * Method engineResolvePublicKey
    *
    * @param element
    * @param BaseURI
    * @param storage
    *
    * @throws KeyResolverException
    */
   abstract public PublicKey engineResolvePublicKey(
      Element element, String BaseURI, StorageResolver storage)
         throws KeyResolverException;

   /**
    * Method engineResolveCertificate
    *
    * @param element
    * @param BaseURI
    * @param storage
    *
    * @throws KeyResolverException
    */
   abstract public X509Certificate engineResolveX509Certificate(
      Element element, String BaseURI, StorageResolver storage)
         throws KeyResolverException;

   /**
    * Method engineResolveSecretKey
    *
    * @param element
    * @param BaseURI
    * @param storage
    *
    * @throws KeyResolverException
    */
   abstract public SecretKey engineResolveSecretKey(
      Element element, String BaseURI, StorageResolver storage)
         throws KeyResolverException;

   /** Field _properties */
   protected java.util.Map _properties = new java.util.HashMap(10);

   /**
    * Method engineSetProperty
    *
    * @param key
    * @param value
    */
   public void engineSetProperty(String key, String value) {

      java.util.Iterator i = this._properties.keySet().iterator();

      while (i.hasNext()) {
         String c = (String) i.next();

         if (c.equals(key)) {
            key = c;

            break;
         }
      }

      this._properties.put(key, value);
   }

   /**
    * Method engineGetProperty
    *
    * @param key
    *
    */
   public String engineGetProperty(String key) {

      java.util.Iterator i = this._properties.keySet().iterator();

      while (i.hasNext()) {
         String c = (String) i.next();

         if (c.equals(key)) {
            key = c;

            break;
         }
      }

      return (String) this._properties.get(key);
   }

   /**
    * Method engineGetPropertyKeys
    *
    *
    */
   public String[] engineGetPropertyKeys() {
      return new String[0];
   }

   /**
    * Method understandsProperty
    *
    * @param propertyToTest
    *
    */
   public boolean understandsProperty(String propertyToTest) {

      String[] understood = this.engineGetPropertyKeys();

      if (understood != null) {
         for (int i = 0; i < understood.length; i++) {
            if (understood[i].equals(propertyToTest)) {
               return true;
            }
         }
      }

      return false;
   }
}