How to Secure Android Shared Preferences?

Question

The common location where SharedPreferences are stored in Android apps is:

/data/data//shared_prefs/
         


        

Answer 1

public class NodeCrypto {

        private String iv = "fedcba9876543210";//Dummy iv (CHANGE IT!)
        private IvParameterSpec ivspec;
        private SecretKeySpec keyspec;
        private Cipher cipher;

        private String SecretKey = "0123456789abcdef";//Dummy secretKey (CHANGE IT!)

        public void doKey(String key)
        {
                ivspec = new IvParameterSpec(iv.getBytes());

                key = padRight(key,16);

                Log.d("hi",key);

                keyspec = new SecretKeySpec(key.getBytes(), "AES");

                try {
                        cipher = Cipher.getInstance("AES/CBC/NoPadding");
                } catch (NoSuchAlgorithmException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                } catch (NoSuchPaddingException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }

        public byte[] encrypt(String text,String key) throws Exception
        {
                if(text == null || text.length() == 0)
                        throw new Exception("Empty string");

                doKey(key);

                byte[] encrypted = null;

                try {
                        cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);

                        encrypted = cipher.doFinal(padString(text).getBytes());
                } catch (Exception e)
                {                       
                        throw new Exception("[encrypt] " + e.getMessage());
                }

                return encrypted;
        }

        public byte[] decrypt(String code,String key) throws Exception
        {
                if(code == null || code.length() == 0)
                        throw new Exception("Empty string");

                byte[] decrypted = null;

                doKey(key);

                try {
                        cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

                        decrypted = cipher.doFinal(hexToBytes(code));
                } catch (Exception e)
                {
                        throw new Exception("[decrypt] " + e.getMessage());
                }
                return decrypted;
        }



        public static String bytesToHex(byte[] data)
        {
                if (data==null)
                {
                        return null;
                }

                int len = data.length;
                String str = "";
                for (int i=0; i