Encrypt passwords in a WebApp

Question

I'm developing a WebApp using JavaEE (Servlets + JSP).

I have found a problem when I want to write some passwords in my app, like a SMTP password. While I'm debugging I have write it in plain, inside the code or in properties file, but I would like to encrypt them somehow.

What I do in developing stage:

private static final String SMTP_PASS = "my_pass";

How could I do that? Any ideas/examples?

Answer 1

private static final String SMTP_PASS = "my_pass_identifier"; //here my_pass_identifier is not the actual password its just an identifier to identify the SMTP password

Create a properties file for storing passwords in encrypted form in key/val pairs. Note you can encrypt the password using EncryptDecrypt class mentioned below and pass the encrypted password in the properties file

SMTP_PASS = nPDHgg/DYzcL2+HsvYZruw==javaxMQyYxBZUsf7c0gh+vkisQA==javax0w+9tvuLzY04TA5FyTVSPw==

Create a class CredentialUtilities which will decrypt the password by reading the password.properties file

public class CredentialUtilities {
    static PasswordEncrypt pe = new PasswordEncrypt();
    public static String  getCredentials(String identifier) throws Exception{

        String credential = "";
        Properties prop = new Properties();
        InputStream input = null;

        try {
           String filename = "password.properties";
            input = CredentialUtilities.class.getClassLoader().getResourceAsStream(filename);
            prop.load(input);
            String property = prop.getProperty(identifier);
            credential = pe.decrypt(property); 
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally{
            if(input!=null){
                try {
                input.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            }
        }
        return credential;

    }
}

Create a class that will Encrypt/Decrypt you password for you

import java.security.NoSuchAlgorithmException;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class EncryptDecrypt {
    public static String ALGORITHM = "AES";
    private static String AES_CBS_PADDING = "AES/CBC/PKCS5Padding";
    private static int AES_128 = 128;


    private static byte[] encryptDecrypt(final int mode, final byte[] key, final byte[] IV, final byte[] message)
            throws Exception {
        final Cipher cipher = Cipher.getInstance(AES_CBS_PADDING);
        final SecretKeySpec keySpec = new SecretKeySpec(key, ALGORITHM);
        final IvParameterSpec ivSpec = new IvParameterSpec(IV);
        cipher.init(mode, keySpec, ivSpec);
        return cipher.doFinal(message);
    }

    public static Map<String, SecretKey> keyGenerator() throws NoSuchAlgorithmException{
        Map<String, SecretKey> map = new HashMap<String, SecretKey>();
         KeyGenerator keyGenerator = KeyGenerator.getInstance(EncryptDecrypt.ALGORITHM);
         keyGenerator.init(AES_128);
         SecretKey key = keyGenerator.generateKey();
         map.put("key", key);
         SecretKey IV = keyGenerator.generateKey();
         map.put("iv", IV);
         return map;

    }


    public static String encrypt(String message) throws Exception{
        Map<String , SecretKey> map = keyGenerator();
        SecretKey key = map.get("key");
        SecretKey IV = map.get("iv");
        byte[] cipherText = encryptDecrypt(Cipher.ENCRYPT_MODE, key.getEncoded(), IV.getEncoded(), message.getBytes());
        String encrypted_message =  Base64.getEncoder().encodeToString(cipherText);
        String encodedKey = Base64.getEncoder().encodeToString(map.get("key").getEncoded());
        String encodedIV = Base64.getEncoder().encodeToString(map.get("iv").getEncoded());

        return encrypted_message+"javax"+encodedIV+"javax"+encodedKey;



    }

    public static String decrypt(String encryptedMessage) throws Exception{
        String[] result = encryptedMessage.split("javax");
        byte[] decodedIV = Base64.getDecoder().decode(result[1]);
        byte[] decodedKey = Base64.getDecoder().decode(result[2]);
        byte[] cipher_text = Base64.getDecoder().decode(result[0]);
        SecretKey IV = new SecretKeySpec(decodedIV, 0, decodedIV.length, "AES");
        SecretKey key = new SecretKeySpec(decodedKey, 0, decodedKey.length, "AES");    
        byte[] decryptedString = encryptDecrypt(Cipher.DECRYPT_MODE, key.getEncoded(), IV.getEncoded(), cipher_text);
        String decryptedMessage = new String(decryptedString);
        return decryptedMessage;

    }


    public static void main(String[] args) throws Exception {
        EncryptDecrypt cu = new EncryptDecrypt();
        String encryptedmessage =  cu.encrypt("usrpswd");
        System.out.println(encryptedmessage);
        String decryptedMessage = cu.decrypt(encryptedmessage);
        System.out.println(decryptedMessage);
    }

}

You can now get the decrypted password whereever you want using.

String SMTP_PASSWORD = new CredentialUtilities().getCredentials(SMTP_PASS);