ArcFour128.java

/**
 * Copyright 2003-2016 SSHTOOLS Limited. All Rights Reserved.
 *
 * For product documentation visit https://www.sshtools.com/
 *
 * This file is part of J2SSH Maverick.
 *
 * J2SSH Maverick is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * J2SSH Maverick 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 J2SSH Maverick.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.sshtools.ssh.components.jce;

import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

public class ArcFour128 extends AbstractJCECipher {

	public ArcFour128() throws IOException {
		super("ARCFOUR", "ARCFOUR", 16, "arcfour128");
	}

	public void init(int mode, byte[] iv, byte[] keydata) throws IOException {
		try {

			cipher = JCEProvider.getProviderForAlgorithm(spec) == null ? Cipher
					.getInstance(spec) : Cipher.getInstance(spec,
					JCEProvider.getProviderForAlgorithm(spec));

			if (cipher == null) {
				throw new IOException("Failed to create cipher engine for "
						+ spec);
			}

			// Create a byte key
			byte[] actualKey = new byte[keylength];
			System.arraycopy(keydata, 0, actualKey, 0, actualKey.length);

			SecretKeySpec kspec = new SecretKeySpec(actualKey, keyspec);

			// Create the cipher according to its algorithm
			cipher.init(((mode == ENCRYPT_MODE) ? Cipher.ENCRYPT_MODE
					: Cipher.DECRYPT_MODE), kspec);

			byte[] tmp = new byte[1536];
			cipher.update(tmp);

		} catch (NoSuchPaddingException nspe) {
			throw new IOException("Padding type not supported");
		} catch (NoSuchAlgorithmException nsae) {
			throw new IOException("Algorithm not supported:" + spec);
		} catch (InvalidKeyException ike) {
			throw new IOException("Invalid encryption key");
		}
	}

	public int getBlockSize() {
		return 8;
	}
}