DigestBase.java

/*
 * Copyright (c) 2018, 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.
 *
 * 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.
 */

import java.security.*;

class DigestBase extends MessageDigestSpi {

    private MessageDigest digest = null;

    public DigestBase(String alg, String provider) throws Exception {
        digest = MessageDigest.getInstance(alg, provider);
    }

    @Override
    protected void engineUpdate(byte input) {
        digest.update(input);
    }

    @Override
    protected void engineUpdate(byte[] input, int offset, int len) {
        digest.update(input, offset, len);
    }

    @Override
    protected byte[] engineDigest() {
        return digest.digest();
    }

    @Override
    protected void engineReset() {
        digest.reset();
    }

    @Override
    protected int engineGetDigestLength() {
        return digest.getDigestLength();
    }

    public static final class MD5 extends DigestBase {
        public MD5() throws Exception {
            super("MD5", "SUN");
        }
    }

    public static final class SHA extends DigestBase {
        public SHA() throws Exception {
            super("SHA", "SUN");
        }
    }

    public static final class SHA256 extends DigestBase {
        public SHA256() throws Exception {
            super("SHA-256", "SUN");
        }
    }
}