Java SecretKeySpec create for DES

import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class Main {
   public static void main(String[] args) throws Exception {
      byte[] input = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d,
            0x0e, 0x0f, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
      byte[] keyBytes = new byte[] { 0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab, (byte) 0xcd, (byte) 0xef };
      byte[] msgNumber = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

      IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);

      SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");

      Cipher cipher = Cipher.getInstance("DES/CBC/PKCS7Padding","BC");

      System.out.println("input : " + Base64.getEncoder().encodeToString(input));

      // encryption pass

      // generate IV

      cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);

      IvParameterSpec encryptionIv = new IvParameterSpec(cipher.doFinal(msgNumber), 0, 8);

      // encrypt message

      cipher.init(Cipher.ENCRYPT_MODE, key, encryptionIv);

      byte[] cipherText = new byte[cipher.getOutputSize(input.length)];

      int ctLength = cipher.update(input, 0, input.length, cipherText, 0);

      ctLength += cipher.doFinal(cipherText, ctLength);

      System.out.println("cipher: " + Base64.getEncoder().encodeToString(cipherText) + " bytes: " + ctLength);

      // decryption pass

      // generate IV

      cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);

      IvParameterSpec decryptionIv = new IvParameterSpec(cipher.doFinal(msgNumber), 0, 8);

      // decrypt message

      cipher.init(Cipher.DECRYPT_MODE, key, decryptionIv);

      byte[] plainText = new byte[cipher.getOutputSize(ctLength)];

      int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);

      ptLength += cipher.doFinal(plainText, ptLength);

      System.out.println("plain : " + Base64.getEncoder().encodeToString(plainText) + " bytes: " + ptLength);
   }/*from   ww  w.  j  a  v a 2s.  c o  m*/
}