[FIXED] Encrypt a field to send to another API

Issue

I have a request where there is a field "number_token" that I need to encrypt to send to another API to validate. What is the best method to do this?

Example:

 "number_token":"123456789"

encrypt:

"number_token":"iIsInN1YieyJpc3MiOiJHZXR3YXk.gcGFnQmFuayBQQI6ImIyYzMxMTlmLWU3ZjktNDZjZS05NTMxLTkyMTNlNWRjNWNiMSIsImlhdCI6MTY1OTgyNjUyOCwiZXhwIjoxNjU5ODI2NzA4fQ.mL-jivitV30N1PLq10CmI4ZWxCcBivGf5QGVus7Vsyw"

Solution

There are many factors to be considered but to get started you can use below logic to encrypt. Credits https://www.javaguides.net/2020/02/java-string-encryption-decryption-example.html?m=1

Here is the complete Java program to encrypt and decrypt string or text in Java:

    import java.nio.charset.StandardCharsets;
    import java.security.MessageDigest;
    import java.security.NoSuchAlgorithmException;
    import java.util.Arrays;
    import java.util.Base64;
    import javax.crypto.Cipher;
    import javax.crypto.spec.SecretKeySpec;
    
    public class AESEncryptionDecryption {
        private static SecretKeySpec secretKey;
        private static byte[] key;
        private static final String ALGORITHM = "AES";
    
        public void prepareSecreteKey(String myKey) {
            MessageDigest sha = null;
            try {
                key = myKey.getBytes(StandardCharsets.UTF_8);
                sha = MessageDigest.getInstance("SHA-1");
                key = sha.digest(key);
                key = Arrays.copyOf(key, 16);
                secretKey = new SecretKeySpec(key, ALGORITHM);
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
        }
    public String encrypt(String strToEncrypt, String secret) {
        try {
            prepareSecreteKey(secret);
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
        } catch (Exception e) {
            System.out.println("Error while encrypting: " + e.toString());
        }
        return null;
    }

    public String decrypt(String strToDecrypt, String secret) {
        try {
            prepareSecreteKey(secret);
            Cipher cipher = Cipher.getInstance(ALGORITHM);
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)));
        } catch (Exception e) {
            System.out.println("Error while decrypting: " + e.toString());
        }
        return null;
    }

    public static void main(String[] args) {
        final String secretKey = "secrete";

        String originalString = "javaguides";

        AESEncryptionDecryption aesEncryptionDecryption = new AESEncryptionDecryption();
        String encryptedString = aesEncryptionDecryption.encrypt(originalString, secretKey);
        String decryptedString = aesEncryptionDecryption.decrypt(encryptedString, secretKey);

        System.out.println(originalString);
        System.out.println(encryptedString);
        System.out.println(decryptedString);
    }
}

Answered By - Alien
Answer Checked By - David Goodson (JavaFixing Volunteer)