gistfile1.java

package com.plannow.highedu.services.impl;

import static org.junit.Assert.*;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

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

public class TestEncryption
{
	private static final int ITERATION_NUMBER = 1000;

	public static String getPasswordHash(String salt, String password)
	{
		try
		{
			byte[] hashedPassword = getHash(ITERATION_NUMBER, password, base64ToByte(salt));

			return byteToBase64(hashedPassword);

		}
		catch (NoSuchAlgorithmException e)
		{
			e.printStackTrace();
		}
		catch (UnsupportedEncodingException e)
		{
			e.printStackTrace();
		}

		return null;
	}

	/**
	 * From a password, a number of iterations and a salt, returns the corresponding digest
	 * 
	 * @param iterationNb
	 *            The number of iterations of the algorithm
	 * @param password
	 *            The password to encrypt
	 * @param salt
	 *            The salt
	 * @return The digested password
	 * @throws NoSuchAlgorithmException
	 *             If the algorithm doesn't exist
	 * @throws UnsupportedEncodingException
	 */
	public static byte[] getHash(int iterationNb, String password, byte[] salt) throws NoSuchAlgorithmException,
			UnsupportedEncodingException
	{
		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;
	}

	public static String byteToBase64(byte[] data)
	{
		return new String(new Base64().encode(data));
	}

	public static byte[] base64ToByte(String data)
	{
		return new Base64().decode(data.getBytes());
	}

	@Test
	public void test1() throws NoSuchAlgorithmException, UnsupportedEncodingException
	{
		// Encrypt part
		byte[] hash = getHash(ITERATION_NUMBER, "mypassword", base64ToByte("mysalt"));
		// this string should be stored in the database
		String hashString = byteToBase64(hash);

		// Check Part
		String salt = "mysalt"; // read the salt from the database
		String hashFromDB = hashString; // read the hash string from the database
		byte[] hashDigest = base64ToByte(hashFromDB);
		byte[] saltDigest = base64ToByte(salt);

		byte[] proposedDigest = getHash(ITERATION_NUMBER, "mypassword", saltDigest);

		assertTrue(Arrays.equals(proposedDigest, hashDigest));
	}
}