package org.hyperion.util;

import java.security.Key;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;

/**
 * Encrypts and decrypts using the DESede algorithm.
 *
 * @author Ryan Greene
 *
 */
public class Cryption {

    /**
     * The sentence being crypted and decrypted.
     */
    private static final String sentence = "Ryan is such a fucking pro if this works.";

    /**
     * The algorithm being used to crypt and decrypt.
     */
    private static final String algorithm = "DESede";

    /**
     * The key instance.
     */
    private static Key key = null;

    /**
     * The cipher instance.
     */
    private static Cipher cipher = null;

    /**
     * Decrypts a string using the DESede algorithm.
     *
     * @param bytes
     *            The encrypted string.
     * @return The decrypted string.
     */
    private static String decrypt(byte[] bytes) {
        try {
            cipher.init(Cipher.DECRYPT_MODE, key);
            return new String(cipher.doFinal(bytes));
        } catch (Exception e) {
            System.err.println(e);
            return null;
        }
    }

    /**
     * Encrypts a string using the DESede algorithm.
     *
     * @param string
     *            The string being encrypted.
     * @return The encrypted string.
     */
    private static byte[] encrypt(String string) {
        try {
            cipher.init(Cipher.ENCRYPT_MODE, key);
            return cipher.doFinal(string.getBytes());
        } catch (Exception e) {
            System.err.println(e);
            return null;
        }
    }

    /**
     * Runs the program.
     *
     * @param args
     *            The running arguments.
     */
    public static void main(String[] args) {
        try {
            key = KeyGenerator.getInstance(algorithm).generateKey();
            cipher = Cipher.getInstance(algorithm);
            System.out.println(encrypt(sentence));
            System.out.println(decrypt(encrypt(sentence)));
        } catch (Exception e) {
            System.err.println(e);
        }
    }
}