/* 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.Session;
import iaik.pkcs.pkcs11.TokenException;
import iaik.pkcs.pkcs11.wrapper.Constants;
import iaik.pkcs.pkcs11.wrapper.PKCS11Constants;
import iaik.pkcs.pkcs11.wrapper.PKCS11Exception;

import java.util.Hashtable;



/**
 * An object of this class represents a key as defined by PKCS#11 2.11.
 * A key is of a specific type: RSA, DSA, DH, ECDSA, EC, X9_42_DH, KEA,
 * GENERIC_SECRET, RC2, RC4, DES, DES2, DES3, CAST, CAST3, CAST5, CAST128,
 * RC5, IDEA, SKIPJACK, BATON, JUNIPER, CDMF, AES or VENDOR_DEFINED.
 * If an application needs to use vendor-defined keys,  it must set a
 * VendorDefinedKeyeBuilder using the setVendorDefinedKeyBuilder method.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (keyType_ <> null)
 *             and (id_ <> null)
 *             and (startDate_ <> null)
 *             and (endDate_ <> null)
 *             and (derive_ <> null)
 *             and (local_ <> null)
 *             and (keyGenMechanism_ <> null)
 */
public class Key extends Storage {

  /**
   * This interface defines the available key types as defined by PKCS#11 2.11:
   * RSA, DSA, DH, ECDSA, KEA, GENERIC_SECRET, RC2, RC4, DES, DES2, DES3, CAST,
   * CAST3, CAST5, CAST128, RC5, IDEA, SKIPJACK, BATON, JUNIPER, CDMF, AES,
   * EC, X9_42_DH or VENDOR_DEFINED.
   *
   * @author Karl Scheibelhofer
   * @version 1.0
   * @invariants
   */
  public interface KeyType {

    /**
     * The indentifier for a RSA key.
     */
    static public final Long RSA            = new Long(PKCS11Constants.CKK_RSA);

    /**
     * The indentifier for a DSA key.
     */
    static public final Long DSA            = new Long(PKCS11Constants.CKK_DSA);

    /**
     * The indentifier for a Diffi-Hellman key.
     */
    static public final Long DH             = new Long(PKCS11Constants.CKK_DH);

    /**
     * The indentifier for a ECDSA key.
     */
    static public final Long ECDSA          = new Long(PKCS11Constants.CKK_ECDSA);

    /**
     * The indentifier for a EC key.
     */
    static public final Long EC             = new Long(PKCS11Constants.CKK_EC);

    /**
     * The indentifier for a EC key.
     */
    static public final Long X9_42_DH       = new Long(PKCS11Constants.CKK_X9_42_DH);

    /**
     * The indentifier for a KEA key.
     */
    static public final Long KEA            = new Long(PKCS11Constants.CKK_KEA);

    /**
     * The indentifier for a generic secret key.
     */
    static public final Long GENERIC_SECRET = new Long(PKCS11Constants.CKK_GENERIC_SECRET);

    /**
     * The indentifier for a RC2 key.
     */
    static public final Long RC2            = new Long(PKCS11Constants.CKK_RC2);

    /**
     * The indentifier for a RC4 key.
     */
    static public final Long RC4            = new Long(PKCS11Constants.CKK_RC4);

    /**
     * The indentifier for a DES key.
     */
    static public final Long DES            = new Long(PKCS11Constants.CKK_DES);

    /**
     * The indentifier for a double-length DES key.
     */
    static public final Long DES2           = new Long(PKCS11Constants.CKK_DES2);

    /**
     * The indentifier for a trible-length DES key (Trible-DES).
     */
    static public final Long DES3           = new Long(PKCS11Constants.CKK_DES3);

    /**
     * The indentifier for a CAST key.
     */
    static public final Long CAST           = new Long(PKCS11Constants.CKK_CAST);

    /**
     * The indentifier for a CAST3 key.
     */
    static public final Long CAST3          = new Long(PKCS11Constants.CKK_CAST3);

    /**
     * The indentifier for a CAST5 key; CAST5 is the same as CAST128.
     */
    static public final Long CAST5          = new Long(PKCS11Constants.CKK_CAST5);

    /**
     * The indentifier for a CAST128 key.
     */
    static public final Long CAST128        = new Long(PKCS11Constants.CKK_CAST128);

    /**
     * The indentifier for a RC5 key.
     */
    static public final Long RC5            = new Long(PKCS11Constants.CKK_RC5);

    /**
     * The indentifier for a IDEA key.
     */
    static public final Long IDEA           = new Long(PKCS11Constants.CKK_IDEA);

    /**
     * The indentifier for a SKIPJACK key.
     */
    static public final Long SKIPJACK       = new Long(PKCS11Constants.CKK_SKIPJACK);

    /**
     * The indentifier for a BATON key.
     */
    static public final Long BATON          = new Long(PKCS11Constants.CKK_BATON);

    /**
     * The indentifier for a JUNIPER key.
     */
    static public final Long JUNIPER        = new Long(PKCS11Constants.CKK_JUNIPER);

    /**
     * The indentifier for a CDMF key.
     */
    static public final Long CDMF           = new Long(PKCS11Constants.CKK_CDMF);

    /**
     * The indentifier for a AES key.
     */
    static public final Long AES            = new Long(PKCS11Constants.CKK_AES);

    /**
     * The indentifier for a Blowfish key.
     */
    static public final Long BLOWFISH            = new Long(PKCS11Constants.CKK_BLOWFISH);

    /**
     * The indentifier for a Twofish key.
     */
    static public final Long TWOFISH            = new Long(PKCS11Constants.CKK_TWOFISH);

    /**
     * The indentifier for a VENDOR_DEFINED key. Any Long object with a
     * value bigger than this one is also a valid vendor-defined key
     * type identifier.
     */
    static public final Long VENDOR_DEFINED = new Long(PKCS11Constants.CKK_VENDOR_DEFINED);

  }

  /**
   * If an application uses vendor defined keys, it must implement this
   * interface and install such an object handler using
   * setVendorDefinedKeyBuilder.
   *
   * @author Karl Scheibelhofer
   * @version 1.0
   * @invariants
   */
  public interface VendorDefinedKeyBuilder {

    /**
     * This method should instanciate an Object of this class or of any
     * sub-class. It can use the given handles and PKCS#11 module to retrieve
     * attributes of the PKCS#11 object from the token.
     *
     * @param session The session to use for reading attributes.
     *                This session must have the appropriate rights; i.e.
     *                it must be a user-session, if it is a private object.
     * @param objectHandle The object handle as given from the PKCS#111 module.
     * @return The object representing the PKCS#11 object.
     *         The returned object can be casted to the
     *         according sub-class.
     * @exception PKCS11Exception If getting the attributes failed.
     * @preconditions (session <> null)
     * @postconditions (result <> null) 
     */
    public Object build(Session session, long objectHandle) throws PKCS11Exception;

  }

  /**
   * The currently set vendor defined key builder, or null.
   */
  protected static VendorDefinedKeyBuilder vendorKeyBuilder_;
  
  /**
   * A table holding string representations for all known key types. Table key 
   * is the key type as Long object.
   */
  protected static Hashtable keyTypeNames_;

  /**
   * The type of this key. Its value is one of KeyType, or one that has a
   * bigger value than VENDOR_DEFINED.
   */
  protected KeyTypeAttribute keyType_;

  /**
   * The identifier (ID) of this key.
   */
  protected ByteArrayAttribute id_;

  /**
   * The start date of this key's validity.
   */
  protected DateAttribute startDate_;

  /**
   * The end date of this key's validity.
   */
  protected DateAttribute endDate_;

  /**
   * True, if other keys can be derived from this key.
   */
  protected BooleanAttribute derive_;

  /**
   * True, if this key was created (generated or copiedfrom a different key) on
   * the token.
   */
  protected BooleanAttribute local_;

  /**
   * The mechanism used to generate the key material.
   */
  protected MechanismAttribute keyGenMechanism_;

  /**
   * The default constructor. An application use this constructor to instanciate
   * a key that serves as a template. It may also be useful for working with
   * vendor-defined keys.
   *
   * @preconditions
   * @postconditions
   */
  public Key() {
    super();
  }

  /**
   * Called by sub-classes to create an instance of a PKCS#11 key.
   *
   * @param session The session to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @param objectHandle The object handle as given from the PKCS#111 module.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions
   */
  protected Key(Session session, long objectHandle)
      throws TokenException
  {
    super(session, objectHandle);
  }

  /**
   * Set a vendor-defined key builder that should be called to create an
   * instance of an vendor-defined PKCS#11 key; i.e. an instance of a
   * vendor defined sub-class of this class.
   *
   * @param builder The vendor-defined key builder. Null to clear any
   *                previously installed vendor-defined builder.
   * @preconditions
   * @postconditions
   */
  public static void setVendorDefinedKeyBuilder(VendorDefinedKeyBuilder builder) {
    vendorKeyBuilder_ = builder;
  }

  /**
   * Get the currently set vendor-defined key builder.
   *
   * @return The currently set vendor-defined key builder or null if
   *         none is set.
   * @preconditions
   * @postconditions
   */
  public static VendorDefinedKeyBuilder getVendorDefinedKeyBuilder() {
    return vendorKeyBuilder_ ;
  }

  /**
   * Get the given key type as string.
   *
   * @param keyType The key type to get as string.
   * @return A string denoting the key type; e.g. "RSA".
   * @preconditions (keyType <> null)
   * @postconditions (result <> null) 
   */
  public static String getKeyTypeName(Long keyType) {
    String keyTypeName;
    
    if (keyType == null) {
      throw new NullPointerException("Argument \"keyType\" must not be null.");
    }
    
    if ((keyType.longValue() & PKCS11Constants.CKK_VENDOR_DEFINED) != 0L) {
      keyTypeName = "Vendor Defined";
    } else {
      if (keyTypeNames_ == null) {
        // setup key type names table
        Hashtable keyTypeNames = new Hashtable(24);
        keyTypeNames.put(KeyType.RSA, "RSA");
        keyTypeNames.put(KeyType.DSA, "DSA");
        keyTypeNames.put(KeyType.DH, "DH");
        keyTypeNames.put(KeyType.ECDSA, "ECDSA");
        keyTypeNames.put(KeyType.EC, "EC");
        keyTypeNames.put(KeyType.X9_42_DH, "X9_42_DH");
        keyTypeNames.put(KeyType.KEA, "KEA");
        keyTypeNames.put(KeyType.GENERIC_SECRET, "GENERIC_SECRET");
        keyTypeNames.put(KeyType.RC2, "RC2");
        keyTypeNames.put(KeyType.RC4, "RC4");
        keyTypeNames.put(KeyType.DES, "DES");
        keyTypeNames.put(KeyType.DES2, "DES2");
        keyTypeNames.put(KeyType.DES3, "DES3");
        keyTypeNames.put(KeyType.CAST, "CAST");
        keyTypeNames.put(KeyType.CAST3, "CAST3");
        keyTypeNames.put(KeyType.CAST5, "CAST5");
        keyTypeNames.put(KeyType.CAST128, "CAST128");
        keyTypeNames.put(KeyType.RC5, "RC5");
        keyTypeNames.put(KeyType.IDEA, "IDEA");
        keyTypeNames.put(KeyType.SKIPJACK, "SKIPJACK");
        keyTypeNames.put(KeyType.BATON, "BATON");
        keyTypeNames.put(KeyType.JUNIPER, "JUNIPER");
        keyTypeNames.put(KeyType.CDMF, "CDMF");
        keyTypeNames.put(KeyType.AES, "AES");
        keyTypeNames.put(KeyType.BLOWFISH, "BLOWFISH");
        keyTypeNames.put(KeyType.TWOFISH, "TWOFISH");
        keyTypeNames_ = keyTypeNames;
      }
      
      keyTypeName = (String) keyTypeNames_.get(keyType);
      if (keyTypeName == null) {
        keyTypeName = "<unknown>";
      }
    }

    return keyTypeName ;
  }

  /**
   * Put all attributes of the given object into the attributes table of this
   * object. This method is only static to be able to access invoke the
   * implementation of this method for each class separately (see use in
   * clone()).
   *
   * @param object The object to handle.
   * @preconditions (object <> null)
   * @postconditions
   */
  protected static void putAttributesInTable(Key object) {
    if (object == null) {
      throw new NullPointerException("Argument \"object\" must not be null.");
    }

    object.attributeTable_.put(Attribute.KEY_TYPE, object.keyType_);
    object.attributeTable_.put(Attribute.ID, object.id_);
    object.attributeTable_.put(Attribute.START_DATE, object.startDate_);
    object.attributeTable_.put(Attribute.END_DATE, object.endDate_);
    object.attributeTable_.put(Attribute.DERIVE, object.derive_);
    object.attributeTable_.put(Attribute.LOCAL, object.local_);
    object.attributeTable_.put(Attribute.KEY_GEN_MECHANISM, object.keyGenMechanism_);
  }

  /**
   * Allocates the attribute objects for this class and adds them to the
   * attribute table.
   *
   * @preconditions
   * @postconditions
   */
  protected void allocateAttributes() {
    super.allocateAttributes();

    keyType_ = new KeyTypeAttribute();
    id_ = new ByteArrayAttribute(Attribute.ID);
    startDate_ = new DateAttribute(Attribute.START_DATE);
    endDate_ = new DateAttribute(Attribute.END_DATE);
    derive_ = new BooleanAttribute(Attribute.DERIVE);
    local_ = new BooleanAttribute(Attribute.LOCAL);
    keyGenMechanism_ = new MechanismAttribute(Attribute.KEY_GEN_MECHANISM);

    putAttributesInTable(this);
  }

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

    clone.keyType_ = (KeyTypeAttribute) this.keyType_.clone();
    clone.id_ = (ByteArrayAttribute) this.id_.clone();
    clone.startDate_ = (DateAttribute) this.startDate_.clone();
    clone.endDate_ = (DateAttribute) this.endDate_.clone();
    clone.derive_ = (BooleanAttribute) this.derive_.clone();
    clone.local_ = (BooleanAttribute) this.local_.clone();
    clone.keyGenMechanism_ = (MechanismAttribute) this.keyGenMechanism_.clone();

    putAttributesInTable(clone); // put all cloned attributes into the new table

    return clone ;
  }

  /**
   * 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 Key) {
      Key other = (Key) otherObject;
      equal = (this == other)
              || (super.equals(other)
                  && this.keyType_.equals(other.keyType_)
                  && this.id_.equals(other.id_)
                  && this.startDate_.equals(other.startDate_)
                  && this.endDate_.equals(other.endDate_)
                  && this.derive_.equals(other.derive_)
                  && this.local_.equals(other.local_)
                  && this.keyGenMechanism_.equals(other.keyGenMechanism_));
    }

    return equal ;
  }

  /**
   * Gets the key type attribute of the PKCS#11 key. Its value must
   * be one of those defined in the KeyType interface or one with an
   * value bigger than KeyType.VENDOR_DEFINED.
   *
   * @return The key type identifier.
   * @preconditions
   * @postconditions (result <> null)
   */
  public LongAttribute getKeyType() {
    return keyType_;
  }

  /**
   * Gets the ID attribute of this key.
   *
   * @return The key identifier attribute.
   * @preconditions
   * @postconditions (result <> null)
   */
  public ByteArrayAttribute getId() {
    return id_;
  }

  /**
   * Gets the start date attribute of the validity of this key.
   *
   * @return The start date of validity.
   * @preconditions
   * @postconditions (result <> null)
   */
  public DateAttribute getStartDate() {
    return startDate_ ;
  }

  /**
   * Gets the end date attribute of the validity of this key.
   *
   * @return The end date of validity.
   * @preconditions
   * @postconditions (result <> null)
   */
  public DateAttribute getEndDate() {
    return endDate_ ;
  }

  /**
   * Check, if other keys can be derived from this key.
   *
   * @return Its value is true, if other keys can be derived from this key.
   * @preconditions
   * @postconditions (result <> null)
   */
  public BooleanAttribute getDerive() {
    return derive_ ;
  }

  /**
   * Check, if this key is a local key; i.e. was generated on the token or
   * created via copy from a different key on the token.
   *
   * @return Its value is true, if the key was created on the token.
   * @preconditions
   * @postconditions (result <> null)
   */
  public BooleanAttribute getLocal() {
    return local_;
  }

  /**
   * Get the mechanism used to generate the key material for this key.
   *
   * @return The mechanism attribute used to generate the key material for this
   *         key.
   * @preconditions
   * @postconditions (result <> null)
   */
  public MechanismAttribute getKeyGenMechanism() {
    return keyGenMechanism_ ;
  }

  /**
   * 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 keyType_.hashCode()
           ^ id_.hashCode() ;
  }

  /**
   * Read the values of the attributes of this object from the token.
   *
   * @param session The session handle to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions
   */
  public void readAttributes(Session session)
      throws TokenException
  {
    super.readAttributes(session);

    Object.getAttributeValue(session, objectHandle_, id_);
    Object.getAttributeValue(session, objectHandle_, startDate_);
    Object.getAttributeValue(session, objectHandle_, endDate_);
    Object.getAttributeValue(session, objectHandle_, derive_);
    Object.getAttributeValue(session, objectHandle_, local_);
    Object.getAttributeValue(session, objectHandle_, keyGenMechanism_);
  }
  
  /**
   * 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(256);

    buffer.append(super.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Key Type: ");
    if (keyType_ != null) {
      buffer.append(keyType_.toString());
    } else {
      buffer.append("<unavailable>");
    }

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("ID: ");
    buffer.append(id_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Start Date: ");
    buffer.append(startDate_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("End Date: ");
    buffer.append(endDate_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Derive: ");
    buffer.append(derive_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Local: ");
    buffer.append(local_.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Key Generation Mechanism: ");
    buffer.append(keyGenMechanism_.toString());

    return buffer.toString() ;
  }

}
