1 page.title=Licensing Overview 2 parent.title=Application Licensing 3 parent.link=index.html 4 @jd:body 5 6 7 <div id="qv-wrapper"> 8 <div id="qv"> 9 10 <h2>Quickview</h2> 11 <ul> 12 <li>Licensing allows you to verify your app was purchased from Google Play</li> 13 <li>Your app maintains control of how it enforces its licensing status</li> 14 <li>The service is free for all developers who publish on Google Play</li> 15 </ul> 16 17 <h2>In this document</h2> 18 <ol> 19 <li><a href="#Secure">License Responses are Secure</a></li> 20 <li><a href="#LVL">Licensing Verification Library</a></li> 21 <li><a href="#Reqs">Requirements and Limitations</a></li> 22 <li><a href="#CopyProtection">Replacement for Copy Protection</a></li> 23 </ol> 24 25 </div> 26 </div> 27 28 29 <p>Google Play Licensing is a network-based service that lets an application query a trusted 30 Google Play licensing server to determine whether the application is licensed to the current 31 device user. The licensing service is based on the capability of the Google Play licensing server 32 to determine whether a given user is licensed to use a given application. Google Play considers a 33 user to be licensed if the user is a recorded purchaser of the application.</p> 34 35 <p>The request starts when your application makes a request to a service hosted by 36 the Google Play client application. The Google Play application then sends a request to 37 the licensing server and receives the result. The Google Play application sends 38 the result to your application, which can allow or disallow further use of the 39 application as needed.</p> 40 41 <p class="note"><strong>Note:</strong> If a version of an app is in the alpha or 42 beta channel, all users who are authorized to download and install that app are 43 considered to be licensed users of the app. For more information, see <a 44 href="{@docRoot}distribute/googleplay/developer-console.html#alpha-beta">Alpha 45 and Beta Testing</a>.</p> 46 47 <div class="figure" style="width:469px"> 48 <img src="{@docRoot}images/licensing_arch.png" alt=""/> 49 <p class="img-caption"><strong>Figure 1.</strong> Your application initiates a 50 license check through the License Verification Library and the Google Play 51 client, which handles communication with the Google Play server.</p> 52 </div> 53 54 <p class="note"><strong>Note:</strong> Previously you could test an app by 55 uploading an unpublished "draft" version. This functionality is no longer 56 supported; instead, you must publish it to the alpha or beta distribution 57 channel. For more information, see <a 58 href="{@docRoot}google/play/billing/billing_testing.html#draft_apps">Draft Apps 59 are No Longer Supported</a>. 60 61 <p>To properly identify the user and determine the license status, the licensing server requires 62 information about the application and user—your application and the Google Play client work 63 together to assemble the information and the Google Play client passes it to the server. </p> 64 65 <p>To help you add licensing to your application, the Android SDK provides a downloadable set of 66 library sources that you can include in your application project: the Google Market 67 Licensing package. The License Verification Library (LVL) is a library you can add to your 68 application that 69 handles all of the licensing-related communication with the Google Play licensing service. With 70 the LVL added to your application, your application can determine its licensing status for the 71 current user by simply calling a method and implementing a callback that receives the status 72 response.</p> 73 74 <p>Your application does not query the licensing server 75 directly, but instead calls the Google Play client over remote IPC to 76 initiate a license request. In the license request:</p> 77 78 <ul> 79 <li>Your application provides: its package name, a nonce that is later used to 80 validate any response from the server, and a callback over which the 81 response can be returned asynchronously.</li> 82 <li>The Google Play client collects the necessary information about the user and the device, 83 such as the device's primary Google account username, IMSI, and other 84 information. It then sends the license check request to the server on behalf of 85 your application.</li> 86 <li>The Google Play server evaluates the request using all available information, attempting 87 to establish the user's identity to a sufficient level of confidence. The server 88 then checks the user identity against purchase records for your application and 89 returns a license response, which the Google Play client returns to your 90 application over the IPC callback.</li> 91 </ul> 92 93 <p>You can choose when, and how often, you want your application to check its 94 license and you have full control over how it handles the response, verifies the 95 signed response data, and enforces access controls.</p> 96 97 <p>Notice that during a license check, your application does not manage any 98 network connections or use any licensing related APIs in the Android platform.</p> 99 100 101 102 103 <h2 id="Secure">License Responses are Secure</h2> 104 105 <p>To ensure the integrity of each license query, the server signs the license 106 response data using an RSA key pair that is shared exclusively between the Google Play 107 server and you.</p> 108 109 <p>The licensing service generates a single licensing key pair for each 110 application and exposes the public key in your application's 111 <strong>Services & APIs</strong> page in the Developer Console. You must copy 112 the public key from the Developer Console and embed it in your application 113 source code. The server retains the private key internally and uses it to sign 114 license responses for the applications you publish with that account.</p> 115 116 <p>When your application receives a signed response, it uses the embedded public 117 key to verify the data. The use of public key cryptography in the licensing 118 service makes it possible for the application to detect responses that have been 119 tampered with or that are spoofed.</p> 120 121 122 123 124 <h2 id="LVL">Licensing Verification Library</h2> 125 126 <p>The Android SDK provides a downloadable package called the Google Market Licensing package, 127 which includes the License Verification Library (LVL). The LVL greatly simplifies the process of 128 adding licensing to your application and helps ensure a more secure, robust implementation for your 129 application. The LVL provides internal classes that handle most of the standard operations of a 130 license query, such as contacting the Google Play client to initiate a license request and 131 verifying and validating the responses. It also exposes interfaces that let you easily plug in your 132 custom code for defining licensing policy and managing access as needed by your application. The key 133 LVL interfaces are: </p> 134 135 <dl> 136 <dt>{@code Policy}</dt> 137 <dd>Your implementation determines whether to allow access to the 138 application, based on the license response received from the server and any 139 other data available (such as from a backend server associated with your 140 application). The implementation can evaluate the various fields of the license 141 response and apply other constraints, if needed. The implementation also lets 142 you manage the handling of license checks that result in errors, such as network 143 errors.</dd> 144 145 <dt>{@code LicenseCheckerCallback}</dt> 146 <dd>Your implementation manages access to the 147 application, based on the result of the {@code Policy} object's handling of the license 148 response. Your implementation can manage access in any way needed, including 149 displaying the license result in the UI or directing the user to purchase the 150 application (if not currently licensed).</dd> 151 </dl> 152 153 154 <p>To help you get started with a {@code Policy}, the LVL provides two fully complete 155 {@code Policy} implementations that you can use without modification or adapt to your 156 needs:</p> 157 158 <dl> 159 <dt><a href="adding-licensing.html#ServerManagedPolicy">{@code ServerManagedPolicy}</a></dt> 160 <dd>A flexible {@code Policy} 161 that uses settings provided by the licensing server to manage response caching 162 and access to the application while the device is offline (such as when the 163 user is on an airplane). For most applications, the use of 164 {@code ServerManagedPolicy} is highly recommended.</dd> 165 166 <dt><a href="adding-licensing.html#StrictPolicy">{@code StrictPolicy}</a></dt> 167 <dd>A restrictive {@code Policy} that 168 does not cache any response data and allows the application access <em>only</em> 169 when the server returns a licensed response.</dd> 170 </dl> 171 172 <p>The LVL is available as a downloadable package of the Android SDK. The 173 package includes both the LVL itself and an example application that shows how 174 the library should be integrated with your application and how your application 175 should manage response data, UI interaction, and error conditions. </p> 176 177 <p>The LVL sources are provided as an Android <em>library project</em>, which 178 means that you can maintain a single set of library sources and share them 179 across multiple applications. A full test environment is also available through 180 the SDK, so you can develop and test the licensing implementation in your 181 applications before publishing them, even if you don't have access to a 182 physical device.</p> 183 184 185 186 187 <h2 id="Reqs">Requirements and Limitations</h2> 188 189 <p>Google Play Licensing is designed to let you apply license controls to 190 applications that you publish through Google Play. The service is not 191 designed to let you control access to applications that are not published 192 through Google Play or that are run on devices that do not offer the Google 193 Play client. </p> 194 195 <p>Here are some points to keep in mind as you implement licensing in your 196 application: </p> 197 198 <ul> 199 <li>An application can use the service only if the Google Play client is 200 installed on its host device and the device is running Android 1.5 (API level 3) 201 or higher.</li> 202 <li>To complete a license check, the licensing server must be accessible over 203 the network. You can implement license caching behaviors to manage access to your application when 204 there is no network connectivity. </li> 205 <li>The security of your application's licensing controls ultimately relies on 206 the design of your implementation itself. The service provides the building 207 blocks that let you securely check licensing, but the actual enforcement and 208 handling of the license are factors are up to you. By following the best 209 practices in the following documents, you can help ensure that your implementation will be 210 secure.</li> 211 <li>Adding licensing to an application does not affect the way the application 212 functions when run on a device that does not offer Google Play.</li> 213 <li>You can implement licensing controls for a free app, but only if you're using the service to 214 provide <a 215 href="{@docRoot}google/play/expansion-files.html">APK expansion files</a>.</li> 216 </ul> 217 218 219 220 <h2 id="CopyProtection">Replacement for Copy Protection</h2> 221 222 <p>Google Play Licensing is a flexible, secure mechanism for controlling 223 access to your applications. It effectively replaces the Copy Protection 224 mechanism (no longer supported) that was previously offered on Google Play and 225 gives you wider distribution potential for your applications. </p> 226 227 <p>Licensing lets you move to a license-based model that is enforceable on 228 all devices that have access to Google Play. Access is not bound to the 229 characteristics of the host device, but to your 230 application on Google Play (through the app's public key) and the 231 licensing policy that you define. Your application can be installed and 232 managed on any device on any storage, including SD card.</p> 233 234 <p>Although no license mechanism can completely prevent all unauthorized use, 235 the licensing service lets you control access for most types of normal usage, 236 across all compatible devices, locked or unlocked, that run Android 1.5 or 237 higher version of the platform.</p> 238 239 <p>To begin adding application licensing to your application, continue to <a 240 href="{@docRoot}google/play/licensing/setting-up.html">Setting Up for Licensing</a>.</p> 241 242 243 244 245 246 247
