/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.android.vending.licensing;
/**
* Interface used as part of a {@link Policy} to allow application authors to obfuscate
* licensing data that will be stored into a SharedPreferences file.
* <p>
* Any transformation scheme must be reversible. Implementing classes may optionally implement an
* integrity check to further prevent modification to preference data. Implementing classes
* should use device-specific information as a key in the obfuscation algorithm to prevent
* obfuscated preferences from being shared among devices.
*/
public interface Obfuscator {
/**
* Obfuscate a string that is being stored into shared preferences.
*
* @param original The data that is to be obfuscated.
* @param key The key for the data that is to be obfuscated.
* @return A transformed version of the original data.
*/
String obfuscate(String original, String key);
/**
* Undo the transformation applied to data by the obfuscate() method.
*
* @param obfuscated The data that is to be un-obfuscated.
* @param key The key for the data that is to be un-obfuscated.
* @return The original data transformed by the obfuscate() method.
* @throws ValidationException Optionally thrown if a data integrity check fails.
*/
String unobfuscate(String obfuscated, String key) throws ValidationException;
}