ca.ualberta.physics.cssdp.util.HashUtils.java Source code

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Here is the source code for ca.ualberta.physics.cssdp.util.HashUtils.java

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/* ============================================================
 * HashUtils.java
 * ============================================================
 * Copyright 2013 University of Alberta
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 * ============================================================ 
 */
package ca.ualberta.physics.cssdp.util;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.apache.commons.codec.binary.Base64;

import com.google.common.base.Throwables;

public class HashUtils {

    /**
     * From a password, a number of iterations and a salt, returns the
     * corresponding digest
     * 
     * @param iterationNb
     *            int The number of iterations of the algorithm
     * @param password
     *            String The password to encrypt
     * @param salt
     *            byte[] The salt
     * @return byte[] The digested password
     * @throws NoSuchAlgorithmException
     *             If the algorithm doesn't exist
     */
    public static byte[] getHash(int iterationNb, String password, byte[] salt) {
        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-1");
            digest.reset();
            digest.update(salt);
            byte[] input = digest.digest(password.getBytes("UTF-8"));
            for (int i = 0; i < iterationNb; i++) {
                digest.reset();
                input = digest.digest(input);
            }
            return input;
        } catch (NoSuchAlgorithmException nsa) {
            throw Throwables.propagate(nsa);
        } catch (UnsupportedEncodingException e) {
            throw Throwables.propagate(e);
        }
    }

    /**
     * From a base 64 representation, returns the corresponding byte[]
     * 
     * @param data
     *            String The base64 representation
     * @return byte[]
     * @throws IOException
     */
    public static byte[] base64ToByte(String data) {
        Base64 decoder = new Base64();
        return decoder.decode(data);
    }

    /**
     * From a byte[] returns a base 64 representation
     * 
     * @param data
     *            byte[]
     * @return String
     * @throws IOException
     */
    public static String byteToBase64(byte[] data) {
        Base64 encoder = new Base64();
        return encoder.encodeAsString(data);
    }

}