/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package javades;

/**
 *
 * @author Joao Bosco M. Sobral
 */
// Full Example to show how to use Java’s JCE to encrypt and decrypt text 
// in DES mechanism.

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
 
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
     
public class JavaDES {
    /**
     * @param args the command line arguments
     */
    
        public static void main(String[] argv) {
 
		try{
 
		    KeyGenerator keygenerator = KeyGenerator.getInstance("DES");
		    SecretKey myDesKey = keygenerator.generateKey();
 
		    Cipher desCipher;
 
		    // Create the cipher 
		    desCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
 
		    // Initialize the cipher for encryption
		    desCipher.init(Cipher.ENCRYPT_MODE, myDesKey);
 
		    //sensitive information
		    byte[] text = "Este eh o algoritmo pioneiro".getBytes();
 
		    System.out.println("Text [Byte Format] : " + text);
		    System.out.println("Text : " + new String(text));
 
		    // Encrypt the text
		    byte[] textEncrypted = desCipher.doFinal(text);
 
		    System.out.println("Text Encryted : " + textEncrypted);
 
		    // Initialize the same cipher for decryption
		    desCipher.init(Cipher.DECRYPT_MODE, myDesKey);
 
		    // Decrypt the text
		    byte[] textDecrypted = desCipher.doFinal(textEncrypted);
 
		    System.out.println("Text Decryted : " + new String(textDecrypted));
 
		}catch(NoSuchAlgorithmException e){
			e.printStackTrace();
		}catch(NoSuchPaddingException e){
			e.printStackTrace();
		}catch(InvalidKeyException e){
			e.printStackTrace();
		}catch(IllegalBlockSizeException e){
			e.printStackTrace();
		}catch(BadPaddingException e){
			e.printStackTrace();
		} 
 
	}
    }