package iaik.pkcs.pkcs11.objects;

import iaik.pkcs.pkcs11.Session;
import iaik.pkcs.pkcs11.TokenException;
import iaik.pkcs.pkcs11.wrapper.Constants;

/**
 * Objects of this class represent DSA domain parameters as specified by PKCS#11
 * v2.11.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (prime_ <> null)
 *             and (subprime_ <> null)
 *             and (base_ <> null)
 *             and (primeBits_ <> null)
 */
public class DSAParams extends DomainParameters {

	/**
	 * The prime (p) of this DSA key.
	 */
	protected ByteArrayAttribute prime_;

	/**
	 * The subprime (q) of this DSA key.
	 */
	protected ByteArrayAttribute subprime_;

	/**
	 * The base (g) of this DSA key.
	 */
	protected ByteArrayAttribute base_;

	/**
	 * The bit length of the prim value.
	 */
	protected LongAttribute primeBits_;

	/**
	 * Deafult Constructor.
	 *
	 * @preconditions
	 * @postconditions
	 */
	public DSAParams() {
		super();
		keyType_.setLongValue(Key.KeyType.DSA);
	}

	/**
	 * Called by getInstance to create an instance of a PKCS#11 DSA private 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 DSAParams(Session session, long objectHandle)
	    throws TokenException
	{
		super(session, objectHandle);
		keyType_.setLongValue(Key.KeyType.DSA);
	}

	/**
	 * The getInstance method of the PrivateKey class uses this method to create
	 * an instance of PKCS#11 DSA domain parameters.
	 *
	 * @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 TokenException If getting the attributes failed.
	 * @preconditions (session <> null)
	 * @postconditions (result <> null) 
	 */
	public static Object getInstance(Session session, long objectHandle)
	    throws TokenException
	{
		return new DSAParams(session, objectHandle);
	}

	/**
	 * 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(DSAParams object) {
		if (object == null) {
			throw new NullPointerException("Argument \"object\" must not be null.");
		}

		object.attributeTable_.put(Attribute.PRIME, object.prime_);
		object.attributeTable_.put(Attribute.SUBPRIME, object.subprime_);
		object.attributeTable_.put(Attribute.BASE, object.base_);
		object.attributeTable_.put(Attribute.PRIME_BITS, object.primeBits_);
	}

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

		prime_ = new ByteArrayAttribute(Attribute.PRIME);
		subprime_ = new ByteArrayAttribute(Attribute.SUBPRIME);
		base_ = new ByteArrayAttribute(Attribute.BASE);
		primeBits_ = new LongAttribute(Attribute.PRIME_BITS);

		putAttributesInTable(this);
	}

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

		clone.prime_ = (ByteArrayAttribute) this.prime_.clone();
		clone.subprime_ = (ByteArrayAttribute) this.subprime_.clone();
		clone.base_ = (ByteArrayAttribute) this.base_.clone();
		clone.primeBits_ = (LongAttribute) this.primeBits_.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 DSAParams) {
			DSAParams other = (DSAParams) otherObject;
			equal = (this == other)
			    || (super.equals(other) && this.prime_.equals(other.prime_)
			        && this.subprime_.equals(other.subprime_) && this.base_.equals(other.base_) && this.primeBits_
			          .equals(other.primeBits_));
		}

		return equal;
	}

	/**
	 * Gets the prime attribute of this DSA key.
	 *
	 * @return The prime attribute.
	 * @preconditions
	 * @postconditions (result <> null)
	 */
	public ByteArrayAttribute getPrime() {
		return prime_;
	}

	/**
	 * Gets the subprime attribute of this DSA key.
	 *
	 * @return The subprime attribute.
	 * @preconditions
	 * @postconditions (result <> null)
	 */
	public ByteArrayAttribute getSubprime() {
		return subprime_;
	}

	/**
	 * Gets the base attribute of this DSA key.
	 *
	 * @return The base attribute.
	 * @preconditions
	 * @postconditions (result <> null)
	 */
	public ByteArrayAttribute getBase() {
		return base_;
	}

	/**
	 * Gets the bit length of the prime value.
	 *
	 * @return The bit length of the prime value.
	 * @preconditions
	 * @postconditions (result <> null)
	 */
	public LongAttribute getPrimeBits() {
		return primeBits_;
	}

	/**
	 * 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_, prime_);
		//    Object.getAttributeValue(session, objectHandle_, subprime_);
		//    Object.getAttributeValue(session, objectHandle_, base_);
		//    Object.getAttributeValue(session, objectHandle_, primeBits_);
		Object.getAttributeValues(session, objectHandle_, new Attribute[] { prime_,
		    subprime_, base_, primeBits_ });
	}

	/**
	 * 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(1024);

		buffer.append(super.toString());

		buffer.append(Constants.NEWLINE);
		buffer.append(Constants.INDENT);
		buffer.append("Prime (hex): ");
		buffer.append(prime_.toString());

		buffer.append(Constants.NEWLINE);
		buffer.append(Constants.INDENT);
		buffer.append("Subprime (hex): ");
		buffer.append(subprime_.toString());

		buffer.append(Constants.NEWLINE);
		buffer.append(Constants.INDENT);
		buffer.append("Base (hex): ");
		buffer.append(base_.toString());

		buffer.append(Constants.NEWLINE);
		buffer.append(Constants.INDENT);
		buffer.append("Prime Bits (dec): ");
		buffer.append(primeBits_.toString(10));

		return buffer.toString();
	}

}
