ninja-core/src/main/java/ninja/utils/CookieEncryption.java
public String encrypt(String data) {

        Objects.requireNonNull(data, "Data to be encrypted");
        
        if (!secretKeySpec.isPresent()) {
            return data;
        }

        try {
            // encrypt data
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec.get());
            byte[] encrypted = cipher.doFinal(data.getBytes(StandardCharsets.UTF_8));

            // convert encrypted bytes to string in base64
            return Base64.encodeBase64URLSafeString(encrypted);

        } catch (InvalidKeyException ex) {
            logger.error(getHelperLogMessage(), ex);
            throw new RuntimeException(ex);
        } catch (GeneralSecurityException ex) {
            logger.error("Failed to encrypt data.", ex);
            return "";
        }
    }
public String encrypt(String data) {

        Objects.requireNonNull(data, "Data to be encrypted");
        
        if (!secretKeySpec.isPresent()) {
            return data;
        }

        try {
            // encrypt data
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec.get());
            byte[] encrypted = cipher.doFinal(data.getBytes(StandardCharsets.UTF_8));

            // convert encrypted bytes to string in base64
            return Base64.encodeBase64URLSafeString(encrypted);

        } catch (InvalidKeyException ex) {
            logger.error(getHelperLogMessage(), ex);
            throw new RuntimeException(ex);
        } catch (GeneralSecurityException ex) {
            logger.error("Failed to encrypt data.", ex);
            return "";
        }
    }
Encrypts data with secret key.

@param data text to encrypt
@return encrypted text in base64 format