/**
    * 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.wss4j.dom.processor;
  
  import java.util.Collections;
  import java.util.List;
  
  import org.w3c.dom.Element;
  import org.apache.wss4j.dom.WSConstants;
  import org.apache.wss4j.dom.engine.WSSecurityEngineResult;
  import org.apache.wss4j.common.crypto.AlgorithmSuite;
  import org.apache.wss4j.common.crypto.AlgorithmSuiteValidator;
  import org.apache.wss4j.common.ext.WSSecurityException;
  import org.apache.wss4j.dom.handler.RequestData;
  import org.apache.wss4j.dom.message.token.DerivedKeyToken;
  import org.apache.wss4j.dom.str.DerivedKeyTokenSTRParser;
  import org.apache.wss4j.dom.str.STRParser;
  import org.apache.wss4j.dom.str.STRParserParameters;
  import org.apache.wss4j.dom.str.STRParserResult;
  
  /**
   * The processor to process <code>wsc:DerivedKeyToken</code>.
   */
  public class DerivedKeyTokenProcessor implements Processor {
  
      public List<WSSecurityEngineResult> handleToken(
          Element elem,
          RequestData data
      ) throws WSSecurityException {
          // Deserialize the DKT
          DerivedKeyToken dkt = new DerivedKeyToken(elem, data.getBSPEnforcer());
  
          // Check for compliance against the defined AlgorithmSuite
          AlgorithmSuite algorithmSuite = data.getAlgorithmSuite();
          if (algorithmSuite != null) {
              AlgorithmSuiteValidator algorithmSuiteValidator = new
                  AlgorithmSuiteValidator(algorithmSuite);
              algorithmSuiteValidator.checkDerivedKeyAlgorithm(
                  dkt.getAlgorithm()
              );
          }
  
          byte[] secret = null;
          Element secRefElement = dkt.getSecurityTokenReferenceElement();
          if (secRefElement != null) {
              STRParserParameters parameters = new STRParserParameters();
              parameters.setData(data);
              parameters.setStrElement(secRefElement);
  
              STRParser strParser = new DerivedKeyTokenSTRParser();
              STRParserResult parserResult = strParser.parseSecurityTokenReference(parameters);
              secret = parserResult.getSecretKey();
          } else {
              throw new WSSecurityException(WSSecurityException.ErrorCode.FAILED_CHECK, "noReference");
          }
  
          String tempNonce = dkt.getNonce();
          if (tempNonce == null) {
              throw new WSSecurityException(WSSecurityException.ErrorCode.FAILURE, "empty",
                                            new Object[] {"Missing wsc:Nonce value"});
          }
          int length = dkt.getLength();
          byte[] keyBytes = dkt.deriveKey(length, secret);
          WSSecurityEngineResult result =
              new WSSecurityEngineResult(WSConstants.DKT, null, keyBytes, null);
          data.getWsDocInfo().addTokenElement(elem);
          String tokenId = dkt.getID();
          if (tokenId.length() != 0) {
              result.put(WSSecurityEngineResult.TAG_ID, tokenId);
          }
          result.put(WSSecurityEngineResult.TAG_DERIVED_KEY_TOKEN, dkt);
          result.put(WSSecurityEngineResult.TAG_SECRET, secret);
          result.put(WSSecurityEngineResult.TAG_TOKEN_ELEMENT, dkt.getElement());
          data.getWsDocInfo().addResult(result);
          return Collections.singletonList(result);
      }
  
  
  }