Java HMAC hmac(byte key[], byte text[])

Description

Internal used.

License

LGPL

Parameter

Parameter	Description
key	a parameter
text	a parameter

Declaration

public static byte[] hmac(byte key[], byte text[]) 

Method Source Code

//package com.java2s;
/*//  w  w w. j a v  a2 s. c o  m
 * Copyrigth (C) 2010 Henrik Baastrup.
 *
 * Licensed under the GNU Lesser General Public License version 3;
 * you may not use this file except in compliance with the License.
 * You should have received a copy of the license together with this
 * file but can obtain a copy of the License at:
 *
 *       http://www.gnu.org/licenses/lgpl-3.0.txt
 *
 * 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.
 *
 */

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Main {
    /**
     * Internal used.
     * @param key
     * @param text
     * @return
     */
    public static byte[] hmac(byte key[], byte text[]) {
        return hmac(key, text, 64);
    }

    /**
     * Internal used.
     * @param key
     * @param text
     * @param blockSize
     * @return
     */
    public static byte[] hmac(byte key[], byte text[], int blockSize) {
        byte key0[];
        if (key.length == blockSize)
            key0 = key;
        else if (key.length < blockSize) {
            key0 = new byte[blockSize];
            for (int i = 0; i < key.length; i++)
                key0[i] = key[i];
            for (int i = key.length; i < blockSize; i++)
                key0[i] = 0;
        } else {
            byte h[] = hash(key);
            key0 = new byte[blockSize];
            int len = blockSize;
            if (h.length < blockSize)
                len = h.length;
            for (int i = 0; i < len; i++)
                key0[i] = h[i];
            for (int i = len; i < blockSize; i++)
                key0[i] = 0;
        }

        byte ipad[] = new byte[key0.length];
        for (int i = 0; i < key0.length; i++)
            ipad[i] = (byte) (key0[i] ^ 0x36);

        byte res[] = new byte[ipad.length + text.length];
        for (int i = 0; i < ipad.length; i++)
            res[i] = ipad[i];
        for (int i = 0; i < text.length; i++)
            res[i + ipad.length] = text[i];
        byte h[] = hash(res);

        byte opad[] = new byte[key0.length];
        for (int i = 0; i < key0.length; i++)
            opad[i] = (byte) (key0[i] ^ 0x5c);

        res = new byte[opad.length + h.length];
        for (int i = 0; i < opad.length; i++)
            res[i] = opad[i];
        for (int i = 0; i < h.length; i++)
            res[i + opad.length] = h[i];

        h = hash(res);

        //        System.out.print("hmac: ");
        //        for (int i=0; i<h.length; i++) System.out.print(Integer.toString( ( h[i] & 0xff ) + 0x100, 16).substring( 1 ));
        //        System.out.println("");
        //        System.out.print("key: ");
        //        for (int i=0; i<key.length; i++) System.out.print(Integer.toString( ( key[i] & 0xff ) + 0x100, 16).substring( 1 ));
        //        System.out.println("");
        //        System.out.print("text: ");
        //        for (int i=0; i<text.length; i++) System.out.print(Integer.toString( ( text[i] & 0xff ) + 0x100, 16).substring( 1 ));
        //        System.out.println("");

        return h;
    }

    private static byte[] hash(byte input[]) {
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("SHA1");
        } catch (NoSuchAlgorithmException ex) {
            ex.printStackTrace();
            return null;
        }

        md.update(input);
        byte digest[] = md.digest();
        return digest;
    }
}

Related

1. hmac(String hash, String data, String key)
2. hmac(String msg, String keyString)
3. HMAC(String username, BigInteger nonce, String hashedPassword)
4. hmac_sha(String crypto, byte[] keyBytes, byte[] text)