/* 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,
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 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY  OF SUCH DAMAGE.
 */

package iaik.pkcs.pkcs11.parameters;

import iaik.pkcs.pkcs11.TokenRuntimeException;
import iaik.pkcs.pkcs11.wrapper.Constants;
import iaik.pkcs.pkcs11.wrapper.Functions;
import iaik.pkcs.pkcs11.wrapper.PKCS11Constants;



/**
 * This abstract class encapsulates parameters for the DH mechanisms
 * Mechanism.ECDH1_DERIVE, Mechanism.ECDH1_COFACTOR_DERIVE,
 * Mechanism.ECMQV_DERIVE, Mechanism.X9_42_DH_DERIVE ,
 * Mechanism.X9_42_DH_HYBRID_DERIVE and Mechanism.X9_42_MQV_DERIVE.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (keyDerivationFunction_ == KeyDerivationFunctionType.NULL)
 *              or (keyDerivationFunction_ == KeyDerivationFunctionType.SHA1_KDF)
 *              or (keyDerivationFunction_ == KeyDerivationFunctionType.SHA1_KDF_ASN1)
 *              or (keyDerivationFunction_ == KeyDerivationFunctionType.SHA1_KDF_CONCATENATE))
 *             and (publicData_ <> null)
 */
abstract public class DHKeyDerivationParameters implements Parameters {

  /**
   * This interface defines the available key derivation function types as
   * defined by PKCS#11: CKD_NULL, CKD_SHA1_KDF, CKD_SHA1_KDF_ASN1,
   * CKD_SHA1_KDF_CONCATENATE.
   *
   * @author Karl Scheibelhofer
   * @version 1.0
   * @invariants
   */
  public interface KeyDerivationFunctionType {

    /**
     * The indentifier for CKD_NULL.
     */
    static public final long NULL = PKCS11Constants.CKD_NULL;

    /**
     * The indentifier for CKD_SHA1_KDF.
     */
    static public final long SHA1_KDF = PKCS11Constants.CKD_SHA1_KDF;

    /**
     * The indentifier for CKD_SHA1_KDF_ASN1.
     */
    static public final long SHA1_KDF_ASN1 = PKCS11Constants.CKD_SHA1_KDF_ASN1;

    /**
     * The indentifier for CKD_SHA1_KDF_CONCATENATE.
     */
    static public final long SHA1_KDF_CONCATENATE = PKCS11Constants.CKD_SHA1_KDF_CONCATENATE;

  }

  /**
   * The key derivation function used on the shared secret value.
   */
  protected long keyDerivationFunction_;

  /**
   * The other partie's public key value.
   */
  protected byte[] publicData_;

  /**
   * Create a new DHKeyDerivationParameters object with the given attributes.
   *
   * @param keyDerivationFunction The key derivation function used on the shared
   *                              secret value.
   *                              One of the values defined in
   *                              KeyDerivationFunctionType.
   * @param publicData The other partie's public key value.
   * @preconditions ((keyDerivationFunction == KeyDerivationFunctionType.NULL)
   *                 or (keyDerivationFunction == KeyDerivationFunctionType.SHA1_KDF)
   *                 or (keyDerivationFunction == KeyDerivationFunctionType.SHA1_KDF_ASN1)
   *                 or (keyDerivationFunction == KeyDerivationFunctionType.SHA1_KDF_CONCATENATE))
   *                and (publicData <> null)
   * @postconditions
   */
  protected DHKeyDerivationParameters(long keyDerivationFunction, byte[] publicData)
  {
    if ((keyDerivationFunction != KeyDerivationFunctionType.NULL)
        && (keyDerivationFunction != KeyDerivationFunctionType.SHA1_KDF)
        && (keyDerivationFunction != KeyDerivationFunctionType.SHA1_KDF_ASN1)
        && (keyDerivationFunction != KeyDerivationFunctionType.SHA1_KDF_CONCATENATE)) {
      throw new IllegalArgumentException("Illegal value for argument\"keyDerivationFunction\": " +
                                         Functions.toHexString(keyDerivationFunction));
    }
    if (publicData == null) {
      throw new NullPointerException("Argument \"publicData\" must not be null.");
    }
    keyDerivationFunction_ = keyDerivationFunction;
    publicData_ = publicData;
  }

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

    try {
      clone = (DHKeyDerivationParameters) super.clone();

      clone.publicData_ = (byte[]) this.publicData_.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 key derivation function used on the shared secret value.
   *
   * @return The key derivation function used on the shared secret value.
   *         One of the values defined in KeyDerivationFunctionType.
   * @preconditions
   * @postconditions
   */
  public long getKeyDerivationFunction() {
    return keyDerivationFunction_ ;
  }

  /**
   * Get the other partie's public key value.
   *
   * @return The other partie's public key value.
   * @preconditions
   * @postconditions (result <> null)
   */
  public byte[] getPublicData() {
    return publicData_ ;
  }

  /**
   * Set the ey derivation function used on the shared secret value.
   *
   * @param keyDerivationFunction The key derivation function used on the shared
   *                              secret value.
   *                              One of the values defined in
   *                              KeyDerivationFunctionType.
   * @preconditions (keyDerivationFunction == KeyDerivationFunctionType.NULL)
   *                or (keyDerivationFunction == KeyDerivationFunctionType.SHA1_KDF))
   *                or (keyDerivationFunction == KeyDerivationFunctionType.SHA1_KDF_ASN1))
   *                or (keyDerivationFunction == KeyDerivationFunctionType.SHA1_KDF_CONCATENATE))
   * @postconditions
   */
  public void setKeyDerivationFunction(long keyDerivationFunction) {
    if ((keyDerivationFunction != KeyDerivationFunctionType.NULL)
        && (keyDerivationFunction != KeyDerivationFunctionType.SHA1_KDF)
        && (keyDerivationFunction != KeyDerivationFunctionType.SHA1_KDF_ASN1)
        && (keyDerivationFunction != KeyDerivationFunctionType.SHA1_KDF_CONCATENATE)) {
      throw new IllegalArgumentException("Illegal value for argument\"keyDerivationFunction\": " +
                                         Functions.toHexString(keyDerivationFunction));
    }
    keyDerivationFunction_ = keyDerivationFunction;
  }

  /**
   * Set the other partie's public key value.
   *
   * @param publicData The other partie's public key value.
   * @preconditions (publicData <> null)
   * @postconditions
   */
  public void setPublicData(byte[] publicData) {
    if (publicData == null) {
      throw new NullPointerException("Argument \"publicData\" must not be null.");
    }
    publicData_ = publicData;
  }

  /**
   * Returns the string representation of this object. Do not parse data from
   * this string, it is for debugging only.
   *
   * @return A string representation of this object.
   */
  public String toString() {
    StringBuffer buffer = new StringBuffer();

    buffer.append(Constants.INDENT);
    buffer.append("Key Derivation Function: ");
    if (keyDerivationFunction_ == KeyDerivationFunctionType.NULL) {
      buffer.append("NULL");
    } else if (keyDerivationFunction_ == KeyDerivationFunctionType.SHA1_KDF) {
      buffer.append("SHA1_KDF");
    } else if (keyDerivationFunction_ == KeyDerivationFunctionType.SHA1_KDF_ASN1) {
      buffer.append("SHA1_KDF_ASN1");
    } else if (keyDerivationFunction_ == KeyDerivationFunctionType.SHA1_KDF_CONCATENATE) {
      buffer.append("SHA1_KDF_CONCATENATE");
    } else {
      buffer.append("<unknown>");
    }
    buffer.append(Constants.NEWLINE);

    buffer.append(Constants.INDENT);
    buffer.append("Public Data: ");
    buffer.append(Functions.toHexString(publicData_));
    // buffer.append(Constants.NEWLINE);

    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 DHKeyDerivationParameters) {
      DHKeyDerivationParameters other = (DHKeyDerivationParameters) otherObject;
      equal = (this == other)
              || ((this.keyDerivationFunction_ == other.keyDerivationFunction_)
                  && Functions.equals(this.publicData_, other.publicData_));
    }

    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 ((int) keyDerivationFunction_)
           ^ Functions.hashCode(publicData_) ;
  }

}