org.apache.sshd.common.cipher.BaseRC4Cipher Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sshd.common.cipher;
import javax.crypto.spec.SecretKeySpec;
import org.apache.sshd.common.util.security.SecurityUtils;
/**
* @author Apache MINA SSHD Project
*/
public class BaseRC4Cipher extends BaseCipher {
public static final int SKIP_SIZE = 1536;
public BaseRC4Cipher(int ivsize, int kdfSize, int keySize, int blkSize) {
super(ivsize, 0, kdfSize, "ARCFOUR", keySize, "RC4", blkSize);
}
@Override
protected byte[] initializeIVData(Mode mode, byte[] iv, int reqLen) {
return iv; // not used in any way
}
@Override
protected javax.crypto.Cipher createCipherInstance(Mode mode, byte[] key, byte[] iv) throws Exception {
javax.crypto.Cipher instance = SecurityUtils.getCipher(getTransformation());
instance.init(
Mode.Encrypt.equals(mode)
? javax.crypto.Cipher.ENCRYPT_MODE
: javax.crypto.Cipher.DECRYPT_MODE,
new SecretKeySpec(key, getAlgorithm()));
byte[] foo = new byte[1];
for (int i = 0; i < SKIP_SIZE; i++) {
instance.update(foo, 0, 1, foo, 0);
}
return instance;
}
}