CredentialSerializerGzipXml.java

//* Licensed Materials - Property of                                  *
//* IBM                                                               *
//*                                                                   *
//* eu.abc4trust.pabce.1.34                                           *
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//* This file is 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            *
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//* under the License.                                                *
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package eu.abc4trust.cryptoEngine.user;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.net.URI;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import eu.abc4trust.xml.Credential;
import eu.abc4trust.xml.ObjectFactory;
import eu.abc4trust.xml.util.XmlUtils;

/**
 * This class serializes credentials by their gzipped XML value.
 * @author enr
 */
public class CredentialSerializerGzipXml implements CredentialSerializer {

  @Override
  public byte[] serializeCredential(Credential cred) {
    try {
      ByteArrayOutputStream ser = new ByteArrayOutputStream();
      ser.write(magicHeader());
      
      GZIPOutputStream gs = new GZIPOutputStream(ser);

      
      ObjectFactory of = new ObjectFactory();
      ByteArrayOutputStream xml = XmlUtils.toXmlAsBaos(of.createCredential(cred), true);
      gs.write(xml.toByteArray());
      gs.close();
      
      return ser.toByteArray();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  @Override
  public Credential unserializeCredential(byte[] data) {
    try {
      ByteArrayInputStream bais = new ByteArrayInputStream(data);
      int header = bais.read();
      if(header != magicHeader()) {
        throw new RuntimeException("Cannot unserialize this credential: header was " + header +
          " expected header " + magicHeader());
      }
      GZIPInputStream gs = new GZIPInputStream(bais);
      return (Credential) XmlUtils.getObjectFromXML(gs, true);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  @Override
  public int magicHeader() {
    return 0x02;
  }
  
  @Override
  public Credential unserializeCredential(byte[] data, URI credentialUri, URI smartcardUri) {
    return unserializeCredential(data);
  }

}