Cipher.java

/*
 * This file is part of "The Java Telnet Application".
 *
 * (c) Matthias L. Jugel, Marcus Mei�ner 1996-2002. All Rights Reserved.
 * The file was changed by Radek Polak to work as midlet in MIDP 1.0
 *
 * Please visit http://javatelnet.org/ for updates and contact.
 *
 * --LICENSE NOTICE--
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 * --LICENSE NOTICE--
 */
package ssh.v1;

/**
 * Cipher class is the type for all other ciphers.
 * 
 * @author Marcus Meissner
 * @version $Id: Cipher.java,v 1.1 2006/01/14 01:56:00 karl Exp $
 */

public abstract class Cipher {

	public static Cipher getInstance( String algorithm ) {
		Class c;
		try {
			//      System.out.println( "--- Cipher needs " + algorithm );
			c = Class.forName( "ssh.v1." + algorithm );
			return (Cipher) c.newInstance();
		}
		catch ( Exception e ) {
		    //System.err.println( "Cipher: " + algorithm + " " + e );
		    return null;
		}
	}

	/**
	 * Encrypt source byte array using the instantiated algorithm.
	 */
	public byte[] encrypt( byte[] src ) {
		byte[] dest = new byte[src.length];
		encrypt( src, 0, dest, 0, src.length );
		return dest;
	}

	/**
	 * The actual encryption takes place here.
	 */
	public abstract void encrypt( byte[] src, int srcOff, byte[] dest, int destOff, int len );

	/**
	 * Decrypt source byte array using the instantiated algorithm.
	 */
	public byte[] decrypt( byte[] src ) {
		byte[] dest = new byte[src.length];
		decrypt( src, 0, dest, 0, src.length );
		return dest;
	}

	/**
	 * The actual decryption takes place here.
	 */
	public abstract void decrypt( byte[] src, int srcOff, byte[] dest, int destOff, int len );

	public abstract void setKey( byte[] key );

	public void setKey( String key ) {
		setKey( key.getBytes() );
	}
}