package client;

import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import java.io.UnsupportedEncodingException;
import java.security.Key;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
import java.text.SimpleDateFormat;

/**
 * User: germano.giudici
 * Date: 3-apr-2009
 */
public class KeyGen {
		static final String TRIPLE_DES_CHIPER = "DESede/ECB/PKCS5Padding";
		static final String TRIPLE_DES_KEY = "DESede";
		static String passphrase = "generate a key of course";
		static Key chiave3DES;
    public static void main(String[] args) throws Exception {
    	
    	

        try {
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy.MM.dd");
            simpleDateFormat.parse(args[0]);
            createKey();
        } catch (Exception e) {
            System.out.println("Uso: Inserire una data nella forma yyyy.MM.dd");
            System.exit(0);
        }

        // Encrypt
        String encrypted = cripta3DES(args[0]);
        System.out.println("activationkey = " + encrypted);

        // Decrypt
        String decrypted = decripta3DES(encrypted);
        System.out.println("data di scadenza = " + decrypted);
        System.out.println("\n\ncopiare la activationkey nella sezione ATTIVAZIONE del file simulatore.properties");
    }


        
        public static String cripta3DES(String value) throws Exception{
            byte[] res = null;
            Cipher cipher = Cipher.getInstance(TRIPLE_DES_CHIPER);
            cipher.init(Cipher.ENCRYPT_MODE, chiave3DES);
            byte[] val = value.getBytes();
            res = new byte[cipher.getOutputSize(val.length)];
            int size = cipher.update(val, 0, val.length, res, 0);
            size += cipher.doFinal(res,size);
            return toString(res,res.length);
        }
        
        public static String decripta3DES(String value) throws Exception{
            Cipher cipher = Cipher.getInstance(TRIPLE_DES_CHIPER);
            cipher.init(Cipher.DECRYPT_MODE, chiave3DES);
            return new String(cipher.doFinal(toByteArray(value)));
          }
        
        private static void createKey() throws Exception{
    			DESedeKeySpec spec = null;
    			spec = new DESedeKeySpec(passphrase.getBytes());
    			chiave3DES = SecretKeyFactory.getInstance(TRIPLE_DES_KEY).generateSecret(spec);
  		}
        
        private static final byte[] toByteArray(String string) throws Exception{
            BASE64Decoder decoder = new BASE64Decoder();
            byte[] raw = decoder.decodeBuffer(string);
            return raw;
        }
        
        private static final String toString(byte[] bytes,int length) {
            BASE64Encoder encoder = new BASE64Encoder();
            String base64 = encoder.encode(bytes);
            return base64;
          }
}