/*
* 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;
/**
* Allows the developer to limit the number of devices using a single license.
* <p>
* The LICENSED response from the server contains a user identifier unique to
* the <application, user> pair. The developer can send this identifier
* to their own server along with some device identifier (a random number
* generated and stored once per application installation,
* {@link android.telephony.TelephonyManager#getDeviceId getDeviceId},
* {@link android.provider.Settings.Secure#ANDROID_ID ANDROID_ID}, etc).
* The more sources used to identify the device, the harder it will be for an
* attacker to spoof.
* <p>
* The server can look at the <application, user, device id> tuple and
* restrict a user's application license to run on at most 10 different devices
* in a week (for example). We recommend not being too restrictive because a
* user might legitimately have multiple devices or be in the process of
* changing phones. This will catch egregious violations of multiple people
* sharing one license.
*/
public interface DeviceLimiter {
/**
* Checks if this device is allowed to use the given user's license.
*
* @param userId the user whose license the server responded with
* @return LICENSED if the device is allowed, NOT_LICENSED if not, RETRY if an error occurs
*/
int isDeviceAllowed(String userId);
}