/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 *
 *  (C) Copyright IBM Corp. 1999 All Rights Reserved.
 *  Copyright 1997 The Open Group Research Institute.  All rights reserved.
 */

package sun.security.krb5.internal.crypto;

import sun.security.krb5.Checksum;
import sun.security.krb5.EncryptedData;
import sun.security.krb5.KrbCryptoException;
import sun.security.krb5.internal.*;

public class DesCbcCrcEType extends DesCbcEType {

    public DesCbcCrcEType() {
    }

    public int eType() {
        return EncryptedData.ETYPE_DES_CBC_CRC;
    }

    public int minimumPadSize() {
        return 4;
    }

    public int confounderSize() {
        return 8;
    }

    public int checksumType() {
        return Checksum.CKSUMTYPE_CRC32;
    }

    public int checksumSize() {
        return 4;
    }

    /**
     * Encrypts data using DES in CBC mode with CRC32.
     * @param data the data to be encrypted.
     * @param key  the secret key to encrypt the data. It is also used as initialization vector during cipher block chaining.
     * @return the buffer for cipher text.
     *
     * @written by Yanni Zhang, Dec 10, 1999
     */
    public byte[] encrypt(byte[] data, byte[] key, int usage)
         throws KrbCryptoException {
        return encrypt(data, key, key, usage);
    }

    /**
     * Decrypts data with provided key using DES in CBC mode with CRC32.
     * @param cipher the cipher text to be decrypted.
     * @param key  the secret key to decrypt the data.
     *
     * @written by Yanni Zhang, Dec 10, 1999
     */
    public byte[] decrypt(byte[] cipher, byte[] key, int usage)
         throws KrbApErrException, KrbCryptoException{
        return decrypt(cipher, key, key, usage);
    }

    protected byte[] calculateChecksum(byte[] data, int size) {
        return crc32.byte2crc32sum_bytes(data, size);
    }

}