/*

 * Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.

 * 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

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 */

package sun.security.krb5.internal.crypto;

import sun.security.krb5.KrbCryptoException;

import sun.security.krb5.internal.*;

import java.security.GeneralSecurityException;

import sun.security.krb5.EncryptedData;

import sun.security.krb5.Checksum;

/*

 * This class encapsulates the encryption type for AES256

 *

 * @author Seema Malkani

 */

public final class Aes256CtsHmacSha1EType extends EType {

    public int eType() {

        return EncryptedData.ETYPE_AES256_CTS_HMAC_SHA1_96;

    }

    public int minimumPadSize() {

        return 0;

    }

    public int confounderSize() {

        return blockSize();

    }

    public int checksumType() {

        return Checksum.CKSUMTYPE_HMAC_SHA1_96_AES256;

    }

    public int checksumSize() {

        return Aes256.getChecksumLength();

    }

    public int blockSize() {

        return 16;

    }

    public int keyType() {

        return Krb5.KEYTYPE_AES;

    }

    public int keySize() {

        return 32; // bytes

    }

    public byte[] encrypt(byte[] data, byte[] key, int usage)

        throws KrbCryptoException {

        byte[] ivec = new byte[blockSize()];

        return encrypt(data, key, ivec, usage);

    }

    public byte[] encrypt(byte[] data, byte[] key, byte[] ivec, int usage)

        throws KrbCryptoException {

        try {

            return Aes256.encrypt(key, usage, ivec, data, 0, data.length);

        } catch (GeneralSecurityException e) {

            KrbCryptoException ke = new KrbCryptoException(e.getMessage());

            ke.initCause(e);

            throw ke;

        }

    }

    public byte[] decrypt(byte[] cipher, byte[] key, int usage)

        throws KrbApErrException, KrbCryptoException {

        byte[] ivec = new byte[blockSize()];

        return decrypt(cipher, key, ivec, usage);

    }

    public byte[] decrypt(byte[] cipher, byte[] key, byte[] ivec, int usage)

        throws KrbApErrException, KrbCryptoException {

        try {

            return Aes256.decrypt(key, usage, ivec, cipher, 0, cipher.length);

        } catch (GeneralSecurityException e) {

            KrbCryptoException ke = new KrbCryptoException(e.getMessage());

            ke.initCause(e);

            throw ke;

        }

    }

    // Override default, because our decrypted data does not return confounder

    // Should eventually get rid of EType.decryptedData and

    // EncryptedData.decryptedData altogether

    public byte[] decryptedData(byte[] data) {

        return data;

    }

}