Java SHA256 SHA256(ByteBuffer buf, int off, int length)

Description

SHA

License

Open Source License

Declaration

public static byte[] SHA256(ByteBuffer buf, int off, int length) 

Method Source Code

//package com.java2s;
/*/*from   ww  w.j a  va 2 s  . c o m*/
 * This file is part of BCNode.
 *
 * Copyright (c) Raphfrk 2013 <www.raphfrk.com/bcnode>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;

public class Main {
    private static final ThreadLocal<MessageDigest> localSHA256 = new ThreadLocal<MessageDigest>() {
        @Override
        protected MessageDigest initialValue() {
            try {
                return MessageDigest.getInstance("SHA-256", "BC");
            } catch (NoSuchAlgorithmException e) {
                throw new IllegalStateException("Bouncy castle should support SHA-256", e);
            } catch (NoSuchProviderException e) {
                throw new IllegalStateException("Bouncy castle should be registered as a provider", e);
            }
        }
    };

    public static byte[] SHA256(ByteBuffer buf, int off, int length) {
        int limit = buf.limit();
        int position = buf.position();
        if (off + length > limit) {
            return null;
        }
        buf.position(off);
        buf.limit(off + length);
        try {
            return SHA256(buf, 1);
        } finally {
            buf.limit(limit);
            buf.position(position);
        }
    }

    public static byte[] SHA256(ByteBuffer buf, int n) {
        MessageDigest d = localSHA256.get();
        d.reset();
        d.update(buf);
        byte[] message = d.digest();
        for (int i = 1; i < n; i++) {
            d.reset();
            message = d.digest(message);
        }
        return message;
    }
}

Related

1. sha256(byte[] data)
2. sha256(byte[] data)
3. SHA256(byte[] input)
4. SHA256(byte[] P)
5. SHA256(byte[] src)
6. sha256(final InputStream inputStream)
7. sha256(final String string)
8. sha256(InputStream data)
9. sha256(String base)