spacetraffic.kiv.zcu.cz.gameelement.MinigamePasswordHasher.java Source code

Introduction

Here is the source code for spacetraffic.kiv.zcu.cz.gameelement.MinigamePasswordHasher.java

Source

/**
 Copyright 2010 FAV ZCU
    
 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 spacetraffic.kiv.zcu.cz.gameelement;

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

import java.io.UnsupportedEncodingException;
import java.security.Key;
import java.security.spec.KeySpec;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * Minigame password hasher class.
 */
public class MinigamePasswordHasher {

    /**
     * Initialization vector.
     */
    private static String INIT_VECTOR = "05yngXV9RCNhmsmt";

    /**
     * PDKBF2 password.
     */
    private static String PDKBF2_PASSWORD = "RrapN54SFry37HXkQuym0AOa5x4HrAeKBJQGgM6E";

    /**
     * Salt.
     */
    private static String SALT = "3Z1OH3m3CpUzGIA6E3vZkPTNMtatK9C5knnhMfaa";

    /**
     * Charset.
     */
    private static final String CHARSET = "UTF-8";

    /**
     * Tranformation algorithm.
     */
    private static final String TRANSFORMATION = "AES/CBC/PKCS5Padding";

    /**
     * Key algorithm.
     */
    private static final String ALGORITHM = "PBKDF2WithHmacSHA1";

    /**
     * Method for  encryption password.
     * @param password password
     * @return encripted password
     * @throws Exception
     */
    public String getEncryptedPassword(String password) throws Exception {
        Cipher cipher = getCipher(Cipher.ENCRYPT_MODE);
        byte[] encryptedPassword = cipher.doFinal(password.getBytes(CHARSET));

        return new String(Base64.encodeBase64(encryptedPassword), CHARSET);
    }

    /**
     * Method for get original password from hashed.
     * @param encryptedPassword encrypted password
     * @return original password
     * @throws Exception
     */
    public String getOriginalPassword(String encryptedPassword) throws Exception {
        byte[] fromBase = Base64.decodeBase64(encryptedPassword.getBytes(CHARSET));

        Cipher cipher = getCipher(Cipher.DECRYPT_MODE);
        byte[] decryptedPassword = cipher.doFinal(fromBase);

        return new String(decryptedPassword);
    }

    /**
     * Method for getting Cipher.
     * @param mode mode
     * @return cipher
     * @throws Exception
     */
    private Cipher getCipher(int mode) throws Exception {
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);

        byte[] initVector = INIT_VECTOR.getBytes(CHARSET);
        cipher.init(mode, generateKey(), new IvParameterSpec(initVector));

        return cipher;
    }

    /**
     * Method for generating key.
     * @return key
     * @throws Exception
     */
    private Key generateKey() throws Exception {
        SecretKeyFactory factory = SecretKeyFactory.getInstance(ALGORITHM);
        char[] pdkbf2Password = PDKBF2_PASSWORD.toCharArray();
        byte[] salt = SALT.getBytes(CHARSET);

        KeySpec keySpec = new PBEKeySpec(pdkbf2Password, salt, 65536, 128);
        SecretKey secretKey = factory.generateSecret(keySpec);
        byte[] encodedKey = secretKey.getEncoded();

        return new SecretKeySpec(encodedKey, "AES");
    }
}