Review

Uses DES which is considered unsafe.

• missing/condition/value_or_state

server/generateChecksumPostsAndReplies.java

main(String[])

class generateChecksumPostsAndReplies {
	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception{

		/*make decoder*/
		DESKeySpec keySpec = new DESKeySpec(CryptoUtil.decode("92LlYoVU1hU="));
		SecretKeyFactory factory = SecretKeyFactory.getInstance("DES");
		SecretKey key = factory.generateSecret(keySpec);
		
		byte[] iv = CryptoUtil.decode(decAndCheck.substring(0, 12));
		Cipher c = Cipher.getInstance("DES/CBC/PKCS5Padding");
		IvParameterSpec ivSpec = new IvParameterSpec(iv);
		c.init(Cipher.DECRYPT_MODE, key, ivSpec);
		
		byte[] content = c.doFinal(CryptoUtil.decode(decAndCheck.substring(12)));
		System.out.println(new String(content, "UTF8"));
		byte[] checksum = Hash.generateChecksum(content);
		System.out.println("\"" + CryptoUtil.encode(checksum) + "\"");
		
	}

}

public class AES {
	public void encrypt(String strDataToEncrypt) {
		try {
			KeyGenerator keyGen = KeyGenerator.getInstance("AES");
			keyGen.init(128);
			SecretKey secretKey = keyGen.generateKey();
			final int AES_KEYLENGTH = 128;
			byte[] iv = new byte[AES_KEYLENGTH / 8];
			SecureRandom prng = new SecureRandom();
			prng.nextBytes(iv);
			
			Cipher aesCipherForEncryption = Cipher.getInstance("AES/CBC/PKCS7Padding");
			aesCipherForEncryption.init(Cipher.ENCRYPT_MODE, secretKey, 
					new IvParameterSpec(iv));
			byte[] byteDataToEncrypt = strDataToEncrypt.getBytes();
			byte[] byteCipherText = aesCipherForEncryption.doFinal(byteDataToEncrypt);
		}
		catch (NoSuchAlgorithmException noSuchAlgo) {
		}
		catch (NoSuchPaddingException noSuchPad) {
		}
		catch (InvalidKeyException invalidKey) {
		}
		catch (BadPaddingException badPadding) {
		}
		catch (IllegalBlockSizeException illegalBlockSize) {
		}
		catch (InvalidAlgorithmParameterException invalidParam) {
		}
	}
	public void decrypt(byte[] cipherText, SecretKey secretKey, byte[] iv){
		try {
			Cipher aesCipherForDecryption = Cipher.getInstance("AES/CBC/PKCS7Padding");
			aesCipherForDecryption.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(iv));
			byte[] byteDecryptedText = aesCipherForDecryption.doFinal(cipherText);
			String decryptedText = new String(byteDecryptedText);
		}
		catch (NoSuchAlgorithmException noSuchAlgo) {
		}
		catch (NoSuchPaddingException noSuchPad) {
		}
		catch (InvalidKeyException invalidKey) {
		}
		catch (BadPaddingException badPadding) {
		}
		catch (IllegalBlockSizeException illegalBlockSize) {
		}
		catch (InvalidAlgorithmParameterException invalidParam) {
		}
	}
}