package des;

import javax.crypto.*;
import javax.crypto.spec.*;
import org.apache.commons.codec.binary.*;

public class DesTest {
	private static final String key = "ae3712e83f0831ee8277f795bfed995e";
	private static final String iv = "1234567812345678";
	
	private static byte[] build3DesKey(String keyStr) throws Exception {
		byte[] key = new byte[24];
		byte[] keyBytes = Hex.decodeHex(keyStr.toCharArray());
		if(keyBytes.length < key.length) {
			System.arraycopy(keyBytes, 0, key, 0, keyBytes.length);
			System.arraycopy(keyBytes, 0, key, 16, 8);
		} else
			System.arraycopy(keyBytes, 0, key, 0, key.length);
		return key;
	}
	
	private static Cipher getCipher(int mode) throws Exception {
		SecretKey deskey = new SecretKeySpec(build3DesKey(key), "DESede");
		IvParameterSpec ivObj = new IvParameterSpec(Hex.decodeHex(iv.toCharArray()));
		Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
		cipher.init(mode, deskey, ivObj);
		return cipher;
	}
	
	public static void main(String[] args) throws Exception {
		Cipher encrypt = getCipher(Cipher.ENCRYPT_MODE);
		Cipher decrypt = getCipher(Cipher.DECRYPT_MODE);
		String content = "secret";
		String ciphertext = String.valueOf(Hex.encodeHex(encrypt.doFinal(content.getBytes()))); 
		System.out.println(ciphertext);
		String plaintext = new String(decrypt.doFinal(Hex.decodeHex(ciphertext.toCharArray())));
		System.out.println(plaintext);
	}
}