Month: January 2018

Base Class : 

import android.util.Base64;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;


import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;

import javax.crypto.NoSuchPaddingException;

import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * Created by ADN Digital on 1/17/2018.
 */

public class EncryptionDecryption {


    public static String encrypt(String value, String key)
            throws UnsupportedEncodingException, InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
    {
        byte[] value_bytes = value.getBytes("UTF-8");
        byte[] key_bytes = getKeyBytes(key);
        return Base64.encodeToString(encrypt(value_bytes, key_bytes, key_bytes), 0);
    }

    public static byte[] encrypt(byte[] paramArrayOfByte1, byte[] paramArrayOfByte2, byte[] paramArrayOfByte3)
            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
    {

        Cipher localCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        localCipher.init(1, new SecretKeySpec(paramArrayOfByte2, "AES"), new IvParameterSpec(paramArrayOfByte3));
        return localCipher.doFinal(paramArrayOfByte1);
    }





    public static String decrypt(String value, String key)
            throws GeneralSecurityException, IOException
    {
        byte[] value_bytes = Base64.decode(value, 0);
        byte[] key_bytes = getKeyBytes(key);
        return new String(decrypt(value_bytes, key_bytes, key_bytes), "UTF-8");
    }

    public static byte[] decrypt(byte[] ArrayOfByte1, byte[] ArrayOfByte2, byte[] ArrayOfByte3)
            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
    {

        Cipher localCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        localCipher.init(2, new SecretKeySpec(ArrayOfByte2, "AES"), new IvParameterSpec(ArrayOfByte3));
        return localCipher.doFinal(ArrayOfByte1);
    }

    public static byte[] getKeyBytes(String paramString)
            throws UnsupportedEncodingException
    {
        byte[] arrayOfByte1 = new byte[16];
        byte[] arrayOfByte2 = paramString.getBytes("UTF-8");
        System.arraycopy(arrayOfByte2, 0, arrayOfByte1, 0, Math.min(arrayOfByte2.length, arrayOfByte1.length));
        return arrayOfByte1;
    }



}



How to use : 

try {
    titleText = EncryptionDecryption.encrypt(title.getText().toString().trim(),"1234");
} catch (Exception e) {
    e.printStackTrace();
}

try {
    titleTextView.setText(EncryptionDecryption.decrypt(SavedData.notes.title,"1234"));
} catch (Exception e) {
    e.printStackTrace();
}