Activation Token Demo

package com.tracker.service.impl;

import lombok.extern.slf4j.Slf4j;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.Key;
import java.time.Instant;
import java.util.Base64;
import java.util.UUID;

@Slf4j
public class CryptoExample {

    private static Base64.Encoder encoder = Base64.getUrlEncoder();
    private static Base64.Decoder decoder = Base64.getUrlDecoder();

    private static final String SIGNING_KEY = "CD1DB294C533DCE6"; // 128 bit key
    private static final Key AES_KEY = new SecretKeySpec(SIGNING_KEY.getBytes(), "AES");
    private static final String SECRET_VALUE = String.format("%s:%s", UUID.randomUUID().toString(), Instant.now().getEpochSecond());

    public static void main(String[] args) throws Exception {
        // Create key and cipher
        Cipher cipher = Cipher.getInstance("AES");

        // encrypt the text
        String encoded = encrypt(SECRET_VALUE, cipher);
        log.info("Encrypted: {}", encoded);

        // decrypt the text
        String decryptedText = decrypt(encoded, cipher);
        log.info("Decrypted: {}",decryptedText);
        log.info("Does decrypted text matches: {}", decryptedText.equals(SECRET_VALUE));
    }

    private static String encrypt(String text, Cipher cipher) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        cipher.init(Cipher.ENCRYPT_MODE, AES_KEY);
        byte[] encrypted = cipher.doFinal(text.getBytes());
        return encoder.encodeToString(encrypted);
    }

    private static String decrypt(String encrypted64, Cipher cipher) throws Exception {
        byte[] encrypted = decoder.decode(encrypted64);
        cipher.init(Cipher.DECRYPT_MODE, AES_KEY);
        return new String(cipher.doFinal(encrypted));
    }


    //=================BouncyCastle=================
/*    public static void main(String[] args) throws Exception {
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

        Key key = new SecretKeySpec(SIGNING_KEY.getBytes(), "AES");
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");

        log.info(new String(SECRET_VALUE.getBytes()));

        // encryption pass
        cipher.init(Cipher.ENCRYPT_MODE, key);

        byte[] cipherText = new byte[cipher.getOutputSize(SECRET_VALUE.length())];
        int ctLength = cipher.update(SECRET_VALUE.getBytes(), 0, SECRET_VALUE.length(), cipherText, 0);
        ctLength += cipher.doFinal(cipherText, ctLength);

        log.info("Encrypted: {}", encoder.encodeToString(cipherText));
        log.info("ct: {}", ctLength);

        // decryption pass
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
        int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
        ptLength += cipher.doFinal(plainText, ptLength);

        log.info("Decrypted: {}", new String(plainText));
        log.info("pt: {}", ptLength);
    }*/
}