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      1 page.title=Device Administration
      2 page.tags="devicepolicymanager","policy","security"
      3 @jd:body
      4 
      5 <div id="qv-wrapper">
      6 <div id="qv">
      7     <h2>In this document</h2>
      8     <ol>
      9 <li><a href="#overview">Device Administration API Overview</a>
     10     <ol>
     11       <li><a href="#how">How does it work?</a></li>
     12       <li><a href="#policies">Policies</a></li>
     13     </ol>
     14   </li>
     15   <li><a href="#sample">Sample Application</a></li>
     16   <li><a href="#developing">Developing a Device Administration Application</a>
     17     <ol>
     18       <li><a href="#manifest">Creating the manifest</a></li>
     19       <li><a href="#code">Implementing the code</a></li>
     20     </ol>
     21   </li>
     22 
     23  </ol>
     24 
     25     <h2>Key classes</h2>
     26     <ol>
     27       <li>{@link android.app.admin.DeviceAdminReceiver}</li>
     28       <li>{@link android.app.admin.DevicePolicyManager}</li>
     29       <li>{@link android.app.admin.DeviceAdminInfo}</li>
     30     </ol>
     31     <h2>Related samples</h2>
     32     <ol>
     33       <li><a
     34 href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">
     35 DeviceAdminSample</a></li>
     36 </ol>
     37 </div>
     38 </div>
     39 
     40 <p>Android 2.2 introduces support for enterprise applications by offering the
     41 Android Device Administration API. The Device Administration API provides device
     42 administration features at the system level.  These APIs allow you to create
     43 security-aware applications that are useful in enterprise settings, in which IT
     44 professionals require rich control over employee devices. For example, the
     45 built-in Android Email application has leveraged the new APIs to improve
     46 Exchange support. Through the Email application, Exchange administrators can
     47 enforce password policies &mdash;  including alphanumeric passwords or numeric
     48 PINs &mdash; across devices. Administrators can also remotely wipe (that is,
     49 restore factory defaults on) lost or stolen handsets. Exchange users can sync
     50 their email and calendar data.</p>
     51 
     52 <p>This document is intended for developers who want to develop enterprise
     53 solutions for Android-powered devices. It discusses the various features
     54 provided by the Device Administration API to provide stronger security for
     55 employee devices that are powered by Android.</p>
     56 
     57 
     58 <h2 id="overview">Device Administration API Overview</h2>
     59 
     60 <p>Here are examples of the types of applications that might use the Device Administration API:</p>
     61 <ul>
     62   <li>Email clients.</li>
     63   <li>Security applications that do remote wipe.</li>
     64   <li>Device management services and applications.</li>
     65 </ul>
     66 
     67 <h3 id="how">How does it work?</h3>
     68 <p>You use the Device Administration API to write device admin applications that users
     69 install on their devices. The device admin application enforces the desired
     70 policies. Here's how it works:</p> <ul>
     71   <li>A system administrator writes a device admin application that enforces
     72 remote/local device security policies. These policies could be hard-coded into
     73 the app, or the application could dynamically fetch policies from a third-party
     74 server. </li>
     75 <li>The  application is installed on users' devices. Android does
     76 not currently have an automated provisioning solution. Some of the ways a sysadmin might
     77 distribute the application to users are as follows:
     78 <ul>
     79 <li>Google Play.</li>
     80 <li>Enabling installation from another store.</li>
     81 <li>Distributing the application through other means, such as email or websites.</li>
     82 
     83 </ul>
     84 
     85 
     86 </li>
     87   <li>The system prompts the user to enable the device admin application. How
     88 and when this happens depends on how the application is implemented.</li>
     89 <li>Once  users enable the device admin application, they are subject to
     90 its policies. Complying with those policies typically confers benefits, such as
     91 access to sensitive systems and data.</li>
     92 </ul>
     93 <p>If users do not enable the device admin app, it remains on the device, but in an inactive state. Users will not be subject to its policies, and they will conversely not get any of the application's benefits&mdash;for example, they may not be able to sync data.</p>
     94 <p>If a user fails to comply with the policies (for example, if a user sets a
     95 password that violates the guidelines), it is up to the application to decide
     96 how to handle this. However, typically this will result in the user not being
     97 able to sync data.</p>
     98 <p>If a device attempts to connect to a server that requires policies not
     99 supported in the Device Administration API, the connection will not
    100 be allowed. The Device Administration API does not currently allow partial
    101 provisioning. In other words, if a device (for example, a legacy device) does
    102 not support all of the stated policies, there is no way to allow the
    103 device to connect.</p>
    104 <p>If a device contains multiple enabled admin applications, the strictest policy is
    105 enforced. There is no way to target a particular admin
    106 application.</p>
    107 <p>To uninstall an existing device admin application, users need to
    108 first unregister the application as an administrator. </p>
    109 
    110 
    111 <h3 id="policies">Policies</h3>
    112 
    113 <p>In an enterprise setting, it's often the case that employee devices must
    114 adhere to a strict set of policies that govern the use of the device. The
    115 Device Administration API supports the  policies listed in Table 1.
    116 Note that the Device Administration API currently only supports passwords for screen
    117 lock:</p>
    118 <p class="table-caption"><strong>Table 1.</strong> Policies supported by the Device Administration API.</p>
    119 <table border="1">
    120   <tr>
    121     <th>Policy</th>
    122     <th>Description</th>
    123   </tr>
    124   <tr>
    125     <td>Password enabled</td>
    126     <td>Requires that devices ask for PIN or passwords.</td>
    127   </tr>
    128   <tr>
    129     <td>Minimum password length</td>
    130     <td>Set the required number of characters for the password. For example, you
    131 can require PIN or passwords to have at least six characters. </td> </tr>
    132   <tr>
    133     <td>Alphanumeric password required</td>
    134     <td>Requires that passwords have a
    135 combination of letters and numbers. They may include symbolic characters.
    136     </td>
    137   </tr>
    138   
    139   <tr>
    140     <td>Complex password required</td>
    141     <td>Requires that passwords must contain at least a letter, a numerical digit, and a special symbol. Introduced in Android 3.0.
    142     </td>
    143   </tr>
    144   
    145 <tr> 
    146   <td>Minimum letters required in password</td> <td>The minimum number of
    147 letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
    148 </tr>
    149   
    150   
    151   <tr> 
    152   <td>Minimum lowercase letters required in password</td> 
    153   <td>The minimum number of lowercase 
    154 letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
    155 </tr>
    156   
    157   <tr> 
    158   <td>Minimum non-letter characters required in password</td> 
    159   <td>The minimum number of
    160 non-letter characters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
    161 </tr>
    162   
    163 <tr> 
    164   <td>Minimum numerical digits required in password</td> 
    165   <td>The minimum number of numerical digits required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
    166 </tr>
    167 
    168 <tr> 
    169   <td>Minimum symbols required in password</td> 
    170   <td>The minimum number of symbols required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
    171 </tr>
    172 
    173 <tr> 
    174   <td>Minimum uppercase letters required in password</td> 
    175   <td>The minimum number of uppercase letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
    176 </tr>
    177 
    178 <tr> 
    179   <td>Password expiration timeout</td> 
    180   <td>When the password will expire, expressed as a delta in milliseconds from when a device admin sets the expiration timeout. Introduced in Android 3.0.</td> 
    181 </tr>
    182 
    183 <tr> 
    184   <td>Password history restriction</td> 
    185   <td>This policy prevents users from reusing the last <em>n</em> unique passwords.
    186  This policy is typically used in conjunction with
    187 {@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()}, which forces
    188 users to update their passwords after a specified amount of time has elapsed.
    189 Introduced in Android 3.0.</td> 
    190 </tr>
    191   
    192   <tr>
    193     <td>Maximum failed password attempts </td>
    194     <td>Specifies how many times a user can enter the wrong password before the
    195 device wipes its data.  The Device Administration API also allows administrators to
    196 remotely reset the device to  factory defaults. This secures data in case the
    197 device is lost or stolen.</td>
    198   </tr>
    199   <tr>
    200     <td>Maximum inactivity time lock</td>
    201     <td>Sets the length of time since the user last touched the screen or
    202 pressed a button before the device locks the screen. When this happens, users
    203 need to enter their PIN or passwords again before they can use their devices and
    204 access data.  The value can be between 1 and 60 minutes.</td> </tr>
    205 
    206 <tr> 
    207 <td>Require storage encryption</td> 
    208 <td>Specifies that the storage area should be encrypted, if the device supports it. 
    209 Introduced in Android 3.0.</td> </tr>
    210 
    211 <tr>
    212   <td>Disable camera</td>
    213   
    214   <td>Specifies that the camera should be disabled. Note that this doesn't have
    215 to be a permanent disabling. The camera can be enabled/disabled dynamically
    216 based on context, time, and so on. Introduced in Android 4.0.</td>
    217   
    218 </tr>
    219 
    220 
    221 </table>
    222 
    223 <h4>Other features</h4>
    224 
    225 <p>In addition to supporting the policies listed in the above table, the Device
    226 Administration API lets you do the following:</p> <ul>
    227   <li>Prompt user to set a new password.</li>
    228   <li>Lock device immediately.</li>
    229   <li>Wipe the device's data (that is, restore the device to its factory defaults).</li>
    230 </ul>
    231 
    232 
    233 <h2 id="sample">Sample Application</h2>
    234 
    235 <p>The examples used in this document are based on the <a
    236 href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">
    237 Device Administration API
    238 sample</a>, which is included in the SDK samples. For information on downloading and
    239 installing the SDK samples, see <a
    240 href="{@docRoot}resources/samples/get.html">
    241 Getting the Samples</a>. Here is the  <a
    242 href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">
    243 complete code</a> for
    244 the sample. </p>
    245 <p>The
    246 sample application offers a demo of device admin features. It presents users
    247 with a user interface that lets them enable the device admin application. Once
    248 they've enabled the application, they can use the buttons in the user interface
    249 to do the following:</p>
    250 <ul>
    251   <li>Set password quality.</li>
    252   <li>Specify requirements for the user's password, such as minimum length, the minimum number of
    253   numeric characters it must contain, and so on.</li>
    254   <li>Set the password. If the password does not conform to the specified
    255 policies, the system  returns an error.</li>
    256   <li>Set how many failed password attempts can occur before the device is wiped
    257 (that is, restored to factory settings).</li>
    258 <li>Set how long from now the password will expire.</li>
    259 <li>Set the password history length (<em>length</em> refers to number of old passwords stored in the history). 
    260 This prevents users from reusing 
    261 one of the last <em>n</em> passwords they previously used.</li>
    262 <li>Specify that the storage area should be encrypted, if the device supports it.</li>
    263   <li>Set the maximum amount of inactive time that can elapse before the device
    264 locks.</li>
    265   <li>Make the device lock immediately.</li>
    266   <li>Wipe the device's data (that is, restore factory settings).</li>
    267   <li>Disable the camera.</li>
    268   
    269 </ul>
    270 
    271 
    272 
    273 <img src="{@docRoot}images/admin/device-admin-app.png"/>
    274 
    275 <p class="img-caption"><strong>Figure 1.</strong> Screenshot of the Sample Application</p>
    276 
    277 
    278 
    279 <h2 id="developing">Developing a Device Administration Application</h2>
    280 
    281 <p>System administrators can use the Device Administration API to write an application
    282 that enforces remote/local device security policy enforcement. This section
    283 summarizes the steps involved in creating a device administration
    284 application.</p>
    285 
    286 <h3 id="manifest">Creating the manifest</h3>
    287 
    288 <p>To use the Device Administration API, the application's
    289 manifest must include the following:</p>
    290 <ul>
    291   <li>A subclass of {@link android.app.admin.DeviceAdminReceiver} that includes the following:
    292     <ul>
    293       <li>The {@link android.Manifest.permission#BIND_DEVICE_ADMIN} permission.</li>
    294       <li>The ability to  respond to the {@link android.app.admin.DeviceAdminReceiver#ACTION_DEVICE_ADMIN_ENABLED}
    295 intent, expressed in the manifest as an intent filter.</li>
    296     </ul>
    297   </li>
    298   <li>A declaration of security policies used in metadata.</li>
    299 </ul>
    300 <p>Here is an excerpt from the Device Administration sample manifest:</p>
    301 <pre>&lt;activity android:name=&quot;.app.DeviceAdminSample&quot;
    302             android:label=&quot;&#64;string/activity_sample_device_admin&quot;&gt;
    303     &lt;intent-filter&gt;
    304         &lt;action android:name=&quot;android.intent.action.MAIN&quot; /&gt;
    305         &lt;category android:name=&quot;android.intent.category.SAMPLE_CODE&quot; /&gt;
    306     &lt;/intent-filter&gt;
    307 &lt;/activity&gt;
    308 &lt;receiver android:name=&quot;.app.DeviceAdminSample$DeviceAdminSampleReceiver&quot;
    309         android:label=&quot;&#64;string/sample_device_admin&quot;
    310         android:description=&quot;&#64;string/sample_device_admin_description&quot;
    311         android:permission=&quot;android.permission.BIND_DEVICE_ADMIN&quot;&gt;
    312     &lt;meta-data android:name=&quot;android.app.device_admin&quot;
    313             android:resource=&quot;&#64;xml/device_admin_sample&quot; /&gt;
    314     &lt;intent-filter&gt;
    315         &lt;action android:name=&quot;android.app.action.DEVICE_ADMIN_ENABLED&quot; /&gt;
    316     &lt;/intent-filter&gt;
    317 &lt;/receiver&gt;</pre>
    318 
    319  <p>Note that:</p>
    320 <ul>
    321 <li>The following attributes refer to string resources that for the sample application reside in
    322 <code>ApiDemos/res/values/strings.xml</code>. For more information about resources, see
    323 <a
    324 href="{@docRoot}guide/topics/resources/index.html">Application Resources</a>.
    325 <ul>
    326 <li><code>android:label=&quot;&#64;string/activity_sample_device_admin&quot;</code> refers to the
    327 user-readable label for the activity.</li>
    328 
    329 <li><code>android:label=&quot;&#64;string/sample_device_admin&quot;</code> refers to the
    330 user-readable label for the permission.</li>
    331 
    332 <li><code>android:description=&quot;&#64;string/sample_device_admin_description&quot;</code> refers to
    333 the user-readable description of the permission. A descripton is typically longer and more
    334 informative than
    335 a label.</li>
    336 </ul>
    337 
    338 
    339 <li><code>android:permission=&quot;android.permission.BIND_DEVICE_ADMIN&quot;
    340 </code> is a permission that a {@link android.app.admin.DeviceAdminReceiver} subclass must
    341 have, to ensure that only the system can interact with the receiver (no application can be granted this permission). This
    342 prevents other applications from abusing your device admin app.</li>
    343 <li><code>android.app.action.DEVICE_ADMIN_ENABLED</code> is the primary
    344 action that a {@link android.app.admin.DeviceAdminReceiver} subclass must handle to be
    345 allowed to manage a device. This is set to the receiver when the user enables
    346 the device admin app. Your code typically handles this in
    347 {@link android.app.admin.DeviceAdminReceiver#onEnabled onEnabled()}. To be supported, the receiver must also
    348 require the {@link android.Manifest.permission#BIND_DEVICE_ADMIN} permission so that other applications
    349 cannot abuse it.  </li>
    350 <li>When a user enables the device admin application, that gives the receiver
    351 permission to perform actions in response to the broadcast of particular system
    352 events. When suitable event arises, the application can impose a policy. For
    353 example, if the user attempts to set a new password that doesn't meet the policy
    354 requirements, the application can prompt the user to pick a different password
    355 that does meet the requirements.</li>
    356 
    357   <li><code>android:resource=&quot;&#64;xml/device_admin_sample&quot;</code>
    358 declares the security policies used in metadata. The metadata provides additional
    359 information specific to the device administrator, as parsed by the {@link
    360 android.app.admin.DeviceAdminInfo} class. Here are the contents of
    361 <code>device_admin_sample.xml</code>:</li>
    362 </ul>
    363 <pre>&lt;device-admin xmlns:android=&quot;http://schemas.android.com/apk/res/android">;
    364   &lt;uses-policies&gt;
    365     &lt;limit-password /&gt;
    366     &lt;watch-login /&gt;
    367     &lt;reset-password /&gt;
    368     &lt;force-lock /&gt;
    369     &lt;wipe-data /&gt;
    370     &lt;expire-password /&gt;
    371     &lt;encrypted-storage /&gt;
    372     &lt;disable-camera /&gt;
    373   &lt;/uses-policies&gt;
    374 &lt;/device-admin&gt;
    375 </pre>
    376 <p> In designing your device administration application, you don't need to
    377 include all of the policies, just the ones that are relevant for your app.
    378 </p>
    379 For more discussion of the manifest file, see the <a
    380 href="{@docRoot}guide/topics/manifest/manifest-intro.html">Android Developers Guide</a>.
    381 
    382 
    383 
    384 <h3 id="code">Implementing the code</h3>
    385 
    386 <p>The Device Administration API includes the following classes:</p>
    387 <dl>
    388   <dt>{@link android.app.admin.DeviceAdminReceiver}</dt>
    389      <dd>Base class for implementing a device administration component. This class provides
    390 a convenience for interpreting the raw intent actions   that are sent by the
    391 system. Your Device Administration application must include a
    392 {@link android.app.admin.DeviceAdminReceiver} subclass.</dd>
    393   <dt>{@link android.app.admin.DevicePolicyManager}</dt>
    394 <dd>A class for managing policies enforced on a device. Most clients of
    395 this class must have published a {@link android.app.admin.DeviceAdminReceiver} that the user
    396 has currently enabled. The {@link android.app.admin.DevicePolicyManager} manages policies for
    397 one or more {@link android.app.admin.DeviceAdminReceiver} instances</dd>
    398   <dt>{@link android.app.admin.DeviceAdminInfo}</dt>
    399 <dd>This class is used to specify metadata
    400 for a device administrator component.</dd>
    401 </dl>
    402 <p>These classes provide the foundation for a fully functional device administration application.
    403 The rest of this section describes how you use the {@link
    404 android.app.admin.DeviceAdminReceiver} and
    405 {@link android.app.admin.DevicePolicyManager} APIs to write a device admin application.</p>
    406 
    407 <h4 id="receiver">Subclassing DeviceAdminReceiver</h4>
    408 <p>To create a device admin application, you must subclass
    409 {@link android.app.admin.DeviceAdminReceiver}. The {@link android.app.admin.DeviceAdminReceiver} class
    410 consists of a series of callbacks that are triggered when particular events
    411 occur.</p>
    412 <p>In its {@link android.app.admin.DeviceAdminReceiver} subclass, the sample application
    413 simply displays a {@link android.widget.Toast} notification in response to particular
    414 events. For example:</p>
    415 <pre>public class DeviceAdminSample extends DeviceAdminReceiver {
    416 
    417     void showToast(Context context, String msg) {
    418         String status = context.getString(R.string.admin_receiver_status, msg);
    419         Toast.makeText(context, status, Toast.LENGTH_SHORT).show();
    420     }
    421 
    422     &#64;Override
    423     public void onEnabled(Context context, Intent intent) {
    424         showToast(context, context.getString(R.string.admin_receiver_status_enabled));
    425     }
    426 
    427     &#64;Override
    428     public CharSequence onDisableRequested(Context context, Intent intent) {
    429         return context.getString(R.string.admin_receiver_status_disable_warning);
    430     }
    431 
    432     &#64;Override
    433     public void onDisabled(Context context, Intent intent) {
    434         showToast(context, context.getString(R.string.admin_receiver_status_disabled));
    435     }
    436 
    437     &#64;Override
    438     public void onPasswordChanged(Context context, Intent intent) {
    439         showToast(context, context.getString(R.string.admin_receiver_status_pw_changed));
    440     }
    441 ...
    442 }</pre>
    443 
    444 
    445 <h4 id="enabling">Enabling the application</h4>
    446 <p>One of the major events a device admin application has to handle is the user
    447 enabling the application. The user must explicitly enable the application for
    448 the policies to be enforced. If the user chooses not to enable the application
    449 it will still be present on the device, but its policies will not be enforced, and the user will not
    450 get any of the application's benefits.</p>
    451 <p>The process of enabling the application begins when the user performs an
    452 action that triggers the {@link android.app.admin.DevicePolicyManager#ACTION_ADD_DEVICE_ADMIN}
    453 intent. In the
    454 sample application, this happens when the user clicks the <strong>Enable
    455 Admin</strong> checkbox. </p>
    456 <p>When the user clicks the <strong>Enable Admin</strong> checkbox, the display
    457 changes to prompt the user to activate the device admin application, as shown in figure
    458 2.</p>
    459 
    460 <img src="{@docRoot}images/admin/device-admin-activate-prompt.png"/>
    461 <p class="img-caption"><strong>Figure 2.</strong> Sample Application: Activating the Application</p>
    462 
    463 <p>Below  is the code that gets executed when the user clicks the <strong>Enable Admin</strong> checkbox. This has the effect of triggering the 
    464 {@link android.preference.Preference.OnPreferenceChangeListener#onPreferenceChange(android.preference.Preference, java.lang.Object) onPreferenceChange()} 
    465 callback. This callback is invoked when the value of this  {@link android.preference.Preference} has been changed by the user and is about to be set and/or persisted. If the user is enabling the application, the display
    466 changes to prompt the user to activate the device admin application, as shown in figure
    467 2. Otherwise, the device admin application is disabled. </p>
    468 
    469 <pre>&#64;Override
    470         public boolean onPreferenceChange(Preference preference, Object newValue) {
    471             if (super.onPreferenceChange(preference, newValue)) {
    472                 return true;
    473             }
    474             boolean value = (Boolean) newValue;
    475             if (preference == mEnableCheckbox) {
    476                 if (value != mAdminActive) {
    477                     if (value) {
    478                         // Launch the activity to have the user enable our admin.
    479                         Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
    480                         intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, mDeviceAdminSample);
    481                         intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,
    482                                 mActivity.getString(R.string.add_admin_extra_app_text));
    483                         startActivityForResult(intent, REQUEST_CODE_ENABLE_ADMIN);
    484                         // return false - don't update checkbox until we're really active
    485                         return false;
    486                     } else {
    487                         mDPM.removeActiveAdmin(mDeviceAdminSample);
    488                         enableDeviceCapabilitiesArea(false);
    489                         mAdminActive = false;
    490                     }
    491                 }
    492             } else if (preference == mDisableCameraCheckbox) {
    493                 mDPM.setCameraDisabled(mDeviceAdminSample, value);
    494                 ...
    495             }
    496             return true;
    497         }</pre>
    498 
    499 
    500 <p>The line
    501 <code>intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,
    502 mDeviceAdminSample)</code> states that <code>mDeviceAdminSample</code> (which is
    503 a {@link android.app.admin.DeviceAdminReceiver} component) is the target policy.
    504 This line invokes the user interface shown in figure 2, which guides users through
    505 adding the device administrator to the system (or allows them to reject it).</p>
    506 
    507 <p>When the application needs to perform an operation that is contingent on the
    508 device admin application being enabled, it confirms that the application is
    509 active. To do this it uses the {@link android.app.admin.DevicePolicyManager} method
    510 {@link android.app.admin.DevicePolicyManager#isAdminActive(android.content.ComponentName) isAdminActive()}. Notice that the {@link android.app.admin.DevicePolicyManager}
    511 method {@link android.app.admin.DevicePolicyManager#isAdminActive(android.content.ComponentName) isAdminActive()} takes a {@link android.app.admin.DeviceAdminReceiver}
    512 component as its argument:</p>
    513 
    514 <pre>
    515 DevicePolicyManager mDPM;
    516 ...
    517 private boolean isActiveAdmin() {
    518     return mDPM.isAdminActive(mDeviceAdminSample);
    519 }
    520 </pre>
    521 
    522 
    523 
    524 <h3 id="admin_ops">Managing policies</h3>
    525 <p>{@link android.app.admin.DevicePolicyManager} is a public class for managing policies
    526 enforced on a device. {@link android.app.admin.DevicePolicyManager} manages policies for one
    527 or more {@link android.app.admin.DeviceAdminReceiver} instances. </p>
    528 <p>You get a handle to the {@link android.app.admin.DevicePolicyManager} as follows: </p>
    529 <pre>
    530 DevicePolicyManager mDPM =
    531     (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
    532 </pre>
    533 <p>This section describes how to use {@link android.app.admin.DevicePolicyManager} to perform
    534  administrative tasks:</p>
    535 <ul>
    536   <li><a href="#pwd">Set password policies</a></li>
    537   <li><a href="#lock">Set  device lock</a></li>
    538   <li><a href="#wipe">Perform data wipe</a></li>
    539 </ul>
    540 
    541 <h4 id="pwd">Set password policies</h4>
    542 <p>{@link android.app.admin.DevicePolicyManager} includes APIs for setting and enforcing the
    543 device password policy. In the Device Administration API, the password only applies to
    544 screen lock. This section describes common password-related tasks.</p>
    545 
    546 <h5>Set a password for the device</h5>
    547 <p>This code displays a user interface prompting the user to set a password:</p>
    548 <pre>Intent intent = new Intent(DevicePolicyManager.ACTION_SET_NEW_PASSWORD);
    549 startActivity(intent);
    550 </pre>
    551 
    552 <h5>Set the password quality</h5>
    553 <p>The password quality can be one of the following {@link android.app.admin.DevicePolicyManager} constants: </p>
    554 <dl>
    555   <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_ALPHABETIC}</dt><dd>The user must enter a
    556 password containing at least alphabetic (or other symbol) characters.</dd>
    557   <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_ALPHANUMERIC}</dt><dd>The user must enter a
    558 password containing at least <em>both</em> numeric <em>and</em> alphabetic (or
    559 other symbol) characters.</dd>
    560   <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_NUMERIC}</dt><dd>The user must enter a   password
    561 containing at least numeric characters.</dd>
    562 <dt>{@link
    563 android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_COMPLEX}</dt><dd>The user
    564 must have entered a password containing at least a letter, a numerical digit and
    565 a special symbol.</dd> 
    566 <dt>{@link
    567 android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_SOMETHING}</dt><dd>The
    568 policy requires some kind
    569 of password, but doesn't care what it is.</dd>
    570   <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_UNSPECIFIED}</dt><dd>
    571   The policy has no requirements   for the password. </dd>
    572 </dl>
    573 <p>For example, this is how you would set the password policy to require an alphanumeric password:</p>
    574 <pre>
    575 DevicePolicyManager mDPM;
    576 ComponentName mDeviceAdminSample;
    577 ...
    578 mDPM.setPasswordQuality(mDeviceAdminSample, DevicePolicyManager.PASSWORD_QUALITY_ALPHANUMERIC);
    579 </pre>
    580 
    581 <h5>Set password content requirements</h5>
    582 
    583 <p>Beginning with Android 3.0, the {@link android.app.admin.DevicePolicyManager} class
    584 includes methods that let you fine-tune the contents of the password. For
    585 example, you could set a policy that states that passwords must contain at least
    586 <em>n</em> uppercase letters. Here are the methods for fine-tuning a password's
    587 contents:</p>
    588 <ul>
    589 
    590 <li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumLetters(android.content.ComponentName,int) setPasswordMinimumLetters()}</li> 
    591 
    592 <li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumLowerCase(android.content.ComponentName,int) setPasswordMinimumLowerCase()}</li>
    593 
    594 <li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumUpperCase(android.content.ComponentName,int) setPasswordMinimumUpperCase()}</li>
    595 
    596 <li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumNonLetter(android.content.ComponentName,int) setPasswordMinimumNonLetter()}</li>
    597 
    598 <li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumNumeric(android.content.ComponentName,int) setPasswordMinimumNumeric()}</li>
    599 
    600 <li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumSymbols(android.content.ComponentName,int) setPasswordMinimumSymbols()}</li>
    601 </ul>
    602 <p>For example, this snippet states that the password must have at least 2 uppercase letters:</p>
    603 <pre>
    604 DevicePolicyManager mDPM;
    605 ComponentName mDeviceAdminSample;
    606 int pwMinUppercase = 2;
    607 ...
    608 mDPM.setPasswordMinimumUpperCase(mDeviceAdminSample, pwMinUppercase);</pre>
    609 
    610 
    611 <h5>Set the minimum password length</h5>
    612 <p>You can specify that a password must be at least the specified minimum
    613 length. For example:</p>
    614 <pre>DevicePolicyManager mDPM;
    615 ComponentName mDeviceAdminSample;
    616 int pwLength;
    617 ...
    618 mDPM.setPasswordMinimumLength(mDeviceAdminSample, pwLength);
    619 </pre>
    620 
    621 <h5>Set maximum failed password attempts</h5>
    622 <p>You can set the maximum number of allowed failed password attempts before the
    623 device is wiped (that is, reset to factory settings). For example:</p>
    624 <pre>DevicePolicyManager mDPM;
    625 ComponentName mDeviceAdminSample;
    626 int maxFailedPw;
    627  ...
    628 mDPM.setMaximumFailedPasswordsForWipe(mDeviceAdminSample, maxFailedPw);</pre>
    629 
    630 <h5 id="expiration">Set password expiration timeout</h5>
    631 <p>Beginning with Android 3.0, you can use the 
    632 {@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()} 
    633 method to set when a password will expire, expressed as a delta in milliseconds from when a device admin sets the expiration timeout. For example:</p>
    634 
    635 <pre>DevicePolicyManager mDPM;
    636 ComponentName mDeviceAdminSample;
    637 long pwExpiration;
    638 ...
    639 mDPM.setPasswordExpirationTimeout(mDeviceAdminSample, pwExpiration);
    640 </pre>
    641     
    642 <h5 id="history">Restrict password based on history</h5>
    643 
    644 <p>Beginning with Android 3.0, you can use the 
    645 {@link android.app.admin.DevicePolicyManager#setPasswordHistoryLength(android.content.ComponentName,int) setPasswordHistoryLength()} 
    646 method to limit users'
    647 ability to reuse old passwords. This method takes a <em>length</em>
    648 parameter, which specifies how many old
    649 passwords are stored. When this policy is active, users cannot enter a new
    650 password that matches the last <em>n</em> passwords. This prevents
    651 users from using the same password over and over. This policy is typically used
    652 in conjunction with 
    653 {@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()},
    654 which forces users
    655 to update their passwords after a specified amount of time has elapsed. </p>
    656 
    657 <p>For example, this snippet prohibits users from reusing any of their last 5 passwords:</p>
    658 
    659 <pre>DevicePolicyManager mDPM;
    660 ComponentName mDeviceAdminSample;
    661 int pwHistoryLength = 5;
    662 ...
    663 mDPM.setPasswordHistoryLength(mDeviceAdminSample, pwHistoryLength);
    664 </pre>
    665 
    666 <h4 id="lock">Set device lock</h4>
    667 <p>You can set the maximum period of user inactivity that can occur before the
    668 device locks. For example:</p>
    669 <pre>
    670 DevicePolicyManager mDPM;
    671 ComponentName mDeviceAdminSample;
    672 ...
    673 long timeMs = 1000L*Long.parseLong(mTimeout.getText().toString());
    674 mDPM.setMaximumTimeToLock(mDeviceAdminSample, timeMs);
    675 </pre>
    676 <p>You can also programmatically tell the device to lock immediately:</p>
    677 <pre>
    678 DevicePolicyManager mDPM;
    679 mDPM.lockNow();</pre>
    680 
    681 
    682 
    683 <h4 id="wipe">Perform data wipe</h4>
    684 
    685 <p>You can use the {@link android.app.admin.DevicePolicyManager} method
    686 {@link android.app.admin.DevicePolicyManager#wipeData wipeData()} to reset the device to factory settings. This is useful
    687 if the device is lost or stolen. Often the decision to wipe the device is the
    688 result of certain conditions being met. For example, you can use
    689 {@link android.app.admin.DevicePolicyManager#setMaximumFailedPasswordsForWipe setMaximumFailedPasswordsForWipe()} to state that a device should be
    690 wiped after a specific number of failed password attempts.</p>
    691 <p>You wipe data as follows:</p>
    692 <pre>
    693 DevicePolicyManager mDPM;
    694 mDPM.wipeData(0);</pre>
    695 <p>The {@link android.app.admin.DevicePolicyManager#wipeData wipeData()} method takes as its parameter a bit mask of
    696 additional options. Currently the value must be 0. </p>
    697 
    698 <h4>Disable camera</h4>
    699 <p>Beginning with Android 4.0, you can disable the camera. Note that this doesn't have to be a permanent disabling. The camera can be enabled/disabled dynamically based on context, time, and so on. </p>
    700 <p>You control whether the camera is disabled by using the 
    701 {@link android.app.admin.DevicePolicyManager#setCameraDisabled(android.content.ComponentName, boolean) setCameraDisabled()} method. For example, this snippet sets the camera to be enabled or disabled based on a checkbox setting:</p>
    702 
    703 <pre>private CheckBoxPreference mDisableCameraCheckbox;
    704 DevicePolicyManager mDPM;
    705 ComponentName mDeviceAdminSample;
    706 ...
    707 mDPM.setCameraDisabled(mDeviceAdminSample, mDisableCameraCheckbox.isChecked());<br />
    708 </pre>
    709 
    710 
    711 <h4 id=storage">Storage encryption</h4>
    712 <p>Beginning with Android 3.0, you can use the 
    713 {@link android.app.admin.DevicePolicyManager#setStorageEncryption(android.content.ComponentName,boolean) setStorageEncryption()} 
    714 method to set a policy requiring encryption of the storage area, where supported.</p>
    715 
    716 <p>For example:</p>
    717 
    718 <pre>
    719 DevicePolicyManager mDPM;
    720 ComponentName mDeviceAdminSample;
    721 ...
    722 mDPM.setStorageEncryption(mDeviceAdminSample, true);
    723 </pre>
    724 <p>
    725 See the <a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html"> Device Administration API sample</a> for a complete
    726 example of how to enable storage encryption.</p>
    727