/* Copyright  (c) 2002 Graz University of Technology. 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 IAIK of Graz University of
 *     Technology."
 * 
 *    Alternately, this acknowledgment may appear in the software itself, if 
 *    and wherever such third-party acknowledgments normally appear.
 *  
 * 4. The names "Graz University of Technology" and "IAIK of Graz University of
 *    Technology" must not be used to endorse or promote products derived from 
 *    this software without prior written permission.
 *  
 * 5. Products derived from this software may not be called 
 *    "IAIK PKCS Wrapper", nor may "IAIK" appear in their name, without prior 
 *    written permission of Graz University of Technology.
 *  
 *  THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 *  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE LICENSOR BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 *  OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 *  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 *  OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY  OF SUCH DAMAGE.
 */

package iaik.pkcs.pkcs11.objects;

import iaik.pkcs.pkcs11.TokenRuntimeException;
import iaik.pkcs.pkcs11.wrapper.Constants;



/**
 * This class does not correspond to any PKCS#11 object. It is only a pair of
 * a private key and a public key.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (publicKey_ <> null)
 *             and (privateKey_ <> null)
 */
public class KeyPair implements Cloneable {

  /**
   * The public key of this key-pair.
   */
  protected PublicKey publicKey_;

  /**
   * The private key of this key-pair.
   */
  protected PrivateKey privateKey_;

  /**
   * Constructor that takes a public and a private key. None can be null.
   *
   * @param publicKey The public key of the key-pair.
   * @param privateKey The private key of the key-pair.
   * @preconditions (publicKey <> null)
   *                and (privateKey <> null)
   * @postconditions
   */
  public KeyPair(PublicKey publicKey, PrivateKey privateKey) {
    if (publicKey == null) {
      throw new NullPointerException("Argument \"publicKey\" must not be null.");
    }
    if (privateKey == null) {
      throw new NullPointerException("Argument \"privateKey\" must not be null.");
    }
    publicKey_ = publicKey;
    privateKey_ = privateKey;
  }

  /**
   * Create a (deep) clone of this object.
   *
   * @return A clone of this object.
   * @preconditions
   * @postconditions (result <> null)
   *                 and (result instanceof KeyPair)
   *                 and (result.equals(this))
   */
  public java.lang.Object clone() {
    KeyPair clone;
    try {
      clone = (KeyPair) super.clone();

      clone.privateKey_ = (PrivateKey) this.privateKey_.clone();
      clone.publicKey_ = (PublicKey) this.publicKey_.clone();
    } catch (CloneNotSupportedException ex) {
      // this must not happen, because this class is cloneable
      throw new TokenRuntimeException("An unexpected clone exception occurred.", ex);
    }

    return clone ;
  }

  /**
   * Get the public key part of this key-pair.
   *
   * @return The public key part of this key-pair.
   * @preconditions
   * @postconditions (result <> null)
   */
  public PublicKey getPublicKey() {
    return publicKey_;
  }

  /**
   * Set the public key part of this key-pair.
   *
   * @param publicKey The public key part of this key-pair.
   * @preconditions (publicKey <> null)
   * @postconditions
   */
  public void setPublicKey(PublicKey publicKey){
    if (publicKey == null) {
      throw new NullPointerException("Argument \"publicKey\" must not be null.");
    }
    publicKey_ = publicKey;
  }

  /**
   * Get the private key part of this key-pair.
   *
   * @return The private key part of this key-pair.
   * @preconditions
   * @postconditions (result <> null)
   */
  public PrivateKey getPrivateKey() {
    return privateKey_;
  }

  /**
   * Set the private key part of this key-pair.
   *
   * @param privateKey The private key part of this key-pair.
   * @preconditions (privateKey <> null)
   * @postconditions
   */
  public void setPrivateKey(PrivateKey privateKey){
    if (privateKey == null) {
      throw new NullPointerException("Argument \"privateKey\" must not be null.");
    }
    privateKey_ = privateKey;
  }

  /**
   * This method returns a string representation of the current object. The
   * output is only for debugging purposes and should not be used for other
   * purposes.
   *
   * @return A string presentation of this object for debugging output.
   * @preconditions
   * @postconditions (result <> null)
   */
  public String toString() {
    StringBuffer buffer = new StringBuffer(128);

    buffer.append(Constants.INDENT);
    buffer.append(publicKey_);

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append(privateKey_);

    return buffer.toString() ;
  }

  /**
   * Compares all member variables of this object with the other object.
   * Returns only true, if all are equal in both objects.
   *
   * @param otherObject The other object to compare to.
   * @return True, if other is an instance of this class and all member
   *         variables of both objects are equal. False, otherwise.
   * @preconditions
   * @postconditions
   */
  public boolean equals(java.lang.Object otherObject) {
    boolean equal = false;

    if (otherObject instanceof KeyPair) {
      KeyPair other = (KeyPair) otherObject;
      equal = (this == other)
              || (this.publicKey_.equals(other.publicKey_)
                  && this.privateKey_.equals(other.privateKey_));
    }

    return equal ;
  }

  /**
   * The overriding of this method should ensure that the objects of this class
   * work correctly in a hashtable.
   *
   * @return The hash code of this object.
   * @preconditions
   * @postconditions
   */
  public int hashCode() {
    return publicKey_.hashCode()
           ^ privateKey_.hashCode() ;
  }

}
