Returns a salted PBKDF2 hash of the password. - Java Security

Java examples for Security:Password

  1. HOME
  2. Java
  3. Security
  4. Password

Description

Returns a salted PBKDF2 hash of the password.

Demo Code

/* //from w  ww  .jav a2s.  c  o  m
 * Password Hashing With PBKDF2 (http://crackstation.net/hashing-security.htm).
 * Copyright (c) 2013, Taylor Hornby
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, 
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation 
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */
//package com.java2s;
import java.security.SecureRandom;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.SecretKeyFactory;
import java.math.BigInteger;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;

public class Main {
    public static final String PBKDF2_ALGORITHM = "PBKDF2WithHmacSHA1";
    public static final int SALT_BYTE_SIZE = 40;
    public static final int HASH_BYTE_SIZE = 40;
    public static final int PBKDF2_ITERATIONS = 1000;

    /**
     * Returns a salted PBKDF2 hash of the password.
     *
     * @param   password    the password to hash
     * @return              a salted PBKDF2 hash of the password
     */
    public static String createHash(String password)
            throws NoSuchAlgorithmException, InvalidKeySpecException {
        return createHash(password.toCharArray());
    }

    /**
     * Returns a salted PBKDF2 hash of the password.
     *
     * @param   password    the password to hash
     * @return              a salted PBKDF2 hash of the password
     */
    public static String createHash(char[] password)
            throws NoSuchAlgorithmException, InvalidKeySpecException {
        // Generate a random salt
        SecureRandom random = new SecureRandom();
        byte[] salt = new byte[SALT_BYTE_SIZE];
        random.nextBytes(salt);

        // Hash the password
        byte[] hash = pbkdf2(password, salt, PBKDF2_ITERATIONS,
                HASH_BYTE_SIZE);
        // format iterations:salt:hash
        return PBKDF2_ITERATIONS + ":" + toHex(salt) + ":" + toHex(hash);
    }

    /**
     *  Computes the PBKDF2 hash of a password.
     *
     * @param   password    the password to hash.
     * @param   salt        the salt
     * @param   iterations  the iteration count (slowness factor)
     * @param   bytes       the length of the hash to compute in bytes
     * @return              the PBDKF2 hash of the password
     */
    private static byte[] pbkdf2(char[] password, byte[] salt,
            int iterations, int bytes) throws NoSuchAlgorithmException,
            InvalidKeySpecException {
        PBEKeySpec spec = new PBEKeySpec(password, salt, iterations,
                bytes * 8);
        SecretKeyFactory skf = SecretKeyFactory
                .getInstance(PBKDF2_ALGORITHM);
        return skf.generateSecret(spec).getEncoded();
    }

    /**
     * Converts a byte array into a hexadecimal string.
     *
     * @param   array       the byte array to convert
     * @return              a length*2 character string encoding the byte array
     */
    private static String toHex(byte[] array) {
        BigInteger bi = new BigInteger(1, array);
        String hex = bi.toString(16);
        int paddingLength = (array.length * 2) - hex.length();
        if (paddingLength > 0)
            return String.format("%0" + paddingLength + "d", 0) + hex;
        else
            return hex;
    }
}

Related Tutorials