device-admin.jd revision bdb05bde0fa5ee9593b068c2b80e3b7d5895fb30
1page.title=Device Administration
2page.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</div>
32</div>
33
34<p>Android 2.2 introduces support for enterprise applications by offering the
35Android Device Administration API. The Device Administration API provides device
36administration features at the system level.  These APIs allow you to create
37security-aware applications that are useful in enterprise settings, in which IT
38professionals require rich control over employee devices. For example, the
39built-in Android Email application has leveraged the new APIs to improve
40Exchange support. Through the Email application, Exchange administrators can
41enforce password policies &mdash;  including alphanumeric passwords or numeric
42PINs &mdash; across devices. Administrators can also remotely wipe (that is,
43restore factory defaults on) lost or stolen handsets. Exchange users can sync
44their email and calendar data.</p>
45
46<p>This document is intended for developers who want to develop enterprise
47solutions for Android-powered devices. It discusses the various features
48provided by the Device Administration API to provide stronger security for
49employee devices that are powered by Android.</p>
50
51
52<h2 id="overview">Device Administration API Overview</h2>
53
54<p>Here are examples of the types of applications that might use the Device Administration API:</p>
55<ul>
56  <li>Email clients.</li>
57  <li>Security applications that do remote wipe.</li>
58  <li>Device management services and applications.</li>
59</ul>
60
61<h3 id="how">How does it work?</h3>
62<p>You use the Device Administration API to write device admin applications that users
63install on their devices. The device admin application enforces the desired
64policies. Here's how it works:</p> <ul>
65  <li>A system administrator writes a device admin application that enforces
66remote/local device security policies. These policies could be hard-coded into
67the app, or the application could dynamically fetch policies from a third-party
68server. </li>
69<li>The  application is installed on users' devices. Android does
70not currently have an automated provisioning solution. Some of the ways a sysadmin might
71distribute the application to users are as follows:
72<ul>
73<li>Google Play.</li>
74<li>Enabling installation from another store.</li>
75<li>Distributing the application through other means, such as email or websites.</li>
76
77</ul>
78
79
80</li>
81  <li>The system prompts the user to enable the device admin application. How
82and when this happens depends on how the application is implemented.</li>
83<li>Once  users enable the device admin application, they are subject to
84its policies. Complying with those policies typically confers benefits, such as
85access to sensitive systems and data.</li>
86</ul>
87<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>
88<p>If a user fails to comply with the policies (for example, if a user sets a
89password that violates the guidelines), it is up to the application to decide
90how to handle this. However, typically this will result in the user not being
91able to sync data.</p>
92<p>If a device attempts to connect to a server that requires policies not
93supported in the Device Administration API, the connection will not
94be allowed. The Device Administration API does not currently allow partial
95provisioning. In other words, if a device (for example, a legacy device) does
96not support all of the stated policies, there is no way to allow the
97device to connect.</p>
98<p>If a device contains multiple enabled admin applications, the strictest policy is
99enforced. There is no way to target a particular admin
100application.</p>
101<p>To uninstall an existing device admin application, users need to
102first unregister the application as an administrator. </p>
103
104
105<h3 id="policies">Policies</h3>
106
107<p>In an enterprise setting, it's often the case that employee devices must
108adhere to a strict set of policies that govern the use of the device. The
109Device Administration API supports the  policies listed in Table 1.
110Note that the Device Administration API currently only supports passwords for screen
111lock:</p>
112<p class="table-caption"><strong>Table 1.</strong> Policies supported by the Device Administration API.</p>
113<table border="1">
114  <tr>
115    <th>Policy</th>
116    <th>Description</th>
117  </tr>
118  <tr>
119    <td>Password enabled</td>
120    <td>Requires that devices ask for PIN or passwords.</td>
121  </tr>
122  <tr>
123    <td>Minimum password length</td>
124    <td>Set the required number of characters for the password. For example, you
125can require PIN or passwords to have at least six characters. </td> </tr>
126  <tr>
127    <td>Alphanumeric password required</td>
128    <td>Requires that passwords have a
129combination of letters and numbers. They may include symbolic characters.
130    </td>
131  </tr>
132  
133  <tr>
134    <td>Complex password required</td>
135    <td>Requires that passwords must contain at least a letter, a numerical digit, and a special symbol. Introduced in Android 3.0.
136    </td>
137  </tr>
138  
139<tr> 
140  <td>Minimum letters required in password</td> <td>The minimum number of
141letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
142</tr>
143  
144  
145  <tr> 
146  <td>Minimum lowercase letters required in password</td> 
147  <td>The minimum number of lowercase 
148letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
149</tr>
150  
151  <tr> 
152  <td>Minimum non-letter characters required in password</td> 
153  <td>The minimum number of
154non-letter characters 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 numerical digits required in password</td> 
159  <td>The minimum number of numerical digits required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
160</tr>
161
162<tr> 
163  <td>Minimum symbols required in password</td> 
164  <td>The minimum number of symbols required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
165</tr>
166
167<tr> 
168  <td>Minimum uppercase letters required in password</td> 
169  <td>The minimum number of uppercase letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
170</tr>
171
172<tr> 
173  <td>Password expiration timeout</td> 
174  <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> 
175</tr>
176
177<tr> 
178  <td>Password history restriction</td> 
179  <td>This policy prevents users from reusing the last <em>n</em> unique passwords.
180 This policy is typically used in conjunction with
181{@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()}, which forces
182users to update their passwords after a specified amount of time has elapsed.
183Introduced in Android 3.0.</td> 
184</tr>
185  
186  <tr>
187    <td>Maximum failed password attempts </td>
188    <td>Specifies how many times a user can enter the wrong password before the
189device wipes its data.  The Device Administration API also allows administrators to
190remotely reset the device to  factory defaults. This secures data in case the
191device is lost or stolen.</td>
192  </tr>
193  <tr>
194    <td>Maximum inactivity time lock</td>
195    <td>Sets the length of time since the user last touched the screen or
196pressed a button before the device locks the screen. When this happens, users
197need to enter their PIN or passwords again before they can use their devices and
198access data.  The value can be between 1 and 60 minutes.</td> </tr>
199
200<tr> 
201<td>Require storage encryption</td> 
202<td>Specifies that the storage area should be encrypted, if the device supports it. 
203Introduced in Android 3.0.</td> </tr>
204
205<tr>
206  <td>Disable camera</td>
207  
208  <td>Specifies that the camera should be disabled. Note that this doesn't have
209to be a permanent disabling. The camera can be enabled/disabled dynamically
210based on context, time, and so on. Introduced in Android 4.0.</td>
211  
212</tr>
213
214
215</table>
216
217<h4>Other features</h4>
218
219<p>In addition to supporting the policies listed in the above table, the Device
220Administration API lets you do the following:</p> <ul>
221  <li>Prompt user to set a new password.</li>
222  <li>Lock device immediately.</li>
223  <li>Wipe the device's data (that is, restore the device to its factory defaults).</li>
224</ul>
225
226
227<h2 id="sample">Sample Application</h2>
228
229<p>The examples used in this document are based on the Device Administration API
230sample, which is included in the SDK samples (available through the
231Android SDK Manager) and located on your system as 
232<code>&lt;sdk_root&gt;/ApiDemos/app/src/main/java/com/example/android/apis/app/DeviceAdminSample.java</code>.</p>
233
234<p>The sample application offers a demo of device admin features. It presents users
235with a user interface that lets them enable the device admin application. Once
236they've enabled the application, they can use the buttons in the user interface
237to do the following:</p>
238<ul>
239  <li>Set password quality.</li>
240  <li>Specify requirements for the user's password, such as minimum length, the minimum number of
241  numeric characters it must contain, and so on.</li>
242  <li>Set the password. If the password does not conform to the specified
243policies, the system  returns an error.</li>
244  <li>Set how many failed password attempts can occur before the device is wiped
245(that is, restored to factory settings).</li>
246<li>Set how long from now the password will expire.</li>
247<li>Set the password history length (<em>length</em> refers to number of old passwords stored in the history). 
248This prevents users from reusing 
249one of the last <em>n</em> passwords they previously used.</li>
250<li>Specify that the storage area should be encrypted, if the device supports it.</li>
251  <li>Set the maximum amount of inactive time that can elapse before the device
252locks.</li>
253  <li>Make the device lock immediately.</li>
254  <li>Wipe the device's data (that is, restore factory settings).</li>
255  <li>Disable the camera.</li>
256  
257</ul>
258
259
260
261<img src="{@docRoot}images/admin/device-admin-app.png"/>
262
263<p class="img-caption"><strong>Figure 1.</strong> Screenshot of the Sample Application</p>
264
265
266
267<h2 id="developing">Developing a Device Administration Application</h2>
268
269<p>System administrators can use the Device Administration API to write an application
270that enforces remote/local device security policy enforcement. This section
271summarizes the steps involved in creating a device administration
272application.</p>
273
274<h3 id="manifest">Creating the manifest</h3>
275
276<p>To use the Device Administration API, the application's
277manifest must include the following:</p>
278<ul>
279  <li>A subclass of {@link android.app.admin.DeviceAdminReceiver} that includes the following:
280    <ul>
281      <li>The {@link android.Manifest.permission#BIND_DEVICE_ADMIN} permission.</li>
282      <li>The ability to  respond to the {@link android.app.admin.DeviceAdminReceiver#ACTION_DEVICE_ADMIN_ENABLED}
283intent, expressed in the manifest as an intent filter.</li>
284    </ul>
285  </li>
286  <li>A declaration of security policies used in metadata.</li>
287</ul>
288<p>Here is an excerpt from the Device Administration sample manifest:</p>
289<pre>&lt;activity android:name=&quot;.app.DeviceAdminSample&quot;
290            android:label=&quot;&#64;string/activity_sample_device_admin&quot;&gt;
291    &lt;intent-filter&gt;
292        &lt;action android:name=&quot;android.intent.action.MAIN&quot; /&gt;
293        &lt;category android:name=&quot;android.intent.category.SAMPLE_CODE&quot; /&gt;
294    &lt;/intent-filter&gt;
295&lt;/activity&gt;
296&lt;receiver android:name=&quot;.app.DeviceAdminSample$DeviceAdminSampleReceiver&quot;
297        android:label=&quot;&#64;string/sample_device_admin&quot;
298        android:description=&quot;&#64;string/sample_device_admin_description&quot;
299        android:permission=&quot;android.permission.BIND_DEVICE_ADMIN&quot;&gt;
300    &lt;meta-data android:name=&quot;android.app.device_admin&quot;
301            android:resource=&quot;&#64;xml/device_admin_sample&quot; /&gt;
302    &lt;intent-filter&gt;
303        &lt;action android:name=&quot;android.app.action.DEVICE_ADMIN_ENABLED&quot; /&gt;
304    &lt;/intent-filter&gt;
305&lt;/receiver&gt;</pre>
306
307 <p>Note that:</p>
308<ul>
309<li>The following attributes refer to string resources that for the sample application reside in
310<code>ApiDemos/res/values/strings.xml</code>. For more information about resources, see
311<a
312href="{@docRoot}guide/topics/resources/index.html">Application Resources</a>.
313<ul>
314<li><code>android:label=&quot;&#64;string/activity_sample_device_admin&quot;</code> refers to the
315user-readable label for the activity.</li>
316
317<li><code>android:label=&quot;&#64;string/sample_device_admin&quot;</code> refers to the
318user-readable label for the permission.</li>
319
320<li><code>android:description=&quot;&#64;string/sample_device_admin_description&quot;</code> refers to
321the user-readable description of the permission. A descripton is typically longer and more
322informative than
323a label.</li>
324</ul>
325
326
327<li><code>android:permission=&quot;android.permission.BIND_DEVICE_ADMIN&quot;
328</code> is a permission that a {@link android.app.admin.DeviceAdminReceiver} subclass must
329have, to ensure that only the system can interact with the receiver (no application can be granted this permission). This
330prevents other applications from abusing your device admin app.</li>
331<li><code>android.app.action.DEVICE_ADMIN_ENABLED</code> is the primary
332action that a {@link android.app.admin.DeviceAdminReceiver} subclass must handle to be
333allowed to manage a device. This is set to the receiver when the user enables
334the device admin app. Your code typically handles this in
335{@link android.app.admin.DeviceAdminReceiver#onEnabled onEnabled()}. To be supported, the receiver must also
336require the {@link android.Manifest.permission#BIND_DEVICE_ADMIN} permission so that other applications
337cannot abuse it.  </li>
338<li>When a user enables the device admin application, that gives the receiver
339permission to perform actions in response to the broadcast of particular system
340events. When suitable event arises, the application can impose a policy. For
341example, if the user attempts to set a new password that doesn't meet the policy
342requirements, the application can prompt the user to pick a different password
343that does meet the requirements.</li>
344
345  <li><code>android:resource=&quot;&#64;xml/device_admin_sample&quot;</code>
346declares the security policies used in metadata. The metadata provides additional
347information specific to the device administrator, as parsed by the {@link
348android.app.admin.DeviceAdminInfo} class. Here are the contents of
349<code>device_admin_sample.xml</code>:</li>
350</ul>
351<pre>&lt;device-admin xmlns:android=&quot;http://schemas.android.com/apk/res/android">;
352  &lt;uses-policies&gt;
353    &lt;limit-password /&gt;
354    &lt;watch-login /&gt;
355    &lt;reset-password /&gt;
356    &lt;force-lock /&gt;
357    &lt;wipe-data /&gt;
358    &lt;expire-password /&gt;
359    &lt;encrypted-storage /&gt;
360    &lt;disable-camera /&gt;
361  &lt;/uses-policies&gt;
362&lt;/device-admin&gt;
363</pre>
364<p> In designing your device administration application, you don't need to
365include all of the policies, just the ones that are relevant for your app.
366</p>
367For more discussion of the manifest file, see the <a
368href="{@docRoot}guide/topics/manifest/manifest-intro.html">Android Developers Guide</a>.
369
370
371
372<h3 id="code">Implementing the code</h3>
373
374<p>The Device Administration API includes the following classes:</p>
375<dl>
376  <dt>{@link android.app.admin.DeviceAdminReceiver}</dt>
377     <dd>Base class for implementing a device administration component. This class provides
378a convenience for interpreting the raw intent actions   that are sent by the
379system. Your Device Administration application must include a
380{@link android.app.admin.DeviceAdminReceiver} subclass.</dd>
381  <dt>{@link android.app.admin.DevicePolicyManager}</dt>
382<dd>A class for managing policies enforced on a device. Most clients of
383this class must have published a {@link android.app.admin.DeviceAdminReceiver} that the user
384has currently enabled. The {@link android.app.admin.DevicePolicyManager} manages policies for
385one or more {@link android.app.admin.DeviceAdminReceiver} instances</dd>
386  <dt>{@link android.app.admin.DeviceAdminInfo}</dt>
387<dd>This class is used to specify metadata
388for a device administrator component.</dd>
389</dl>
390<p>These classes provide the foundation for a fully functional device administration application.
391The rest of this section describes how you use the {@link
392android.app.admin.DeviceAdminReceiver} and
393{@link android.app.admin.DevicePolicyManager} APIs to write a device admin application.</p>
394
395<h4 id="receiver">Subclassing DeviceAdminReceiver</h4>
396<p>To create a device admin application, you must subclass
397{@link android.app.admin.DeviceAdminReceiver}. The {@link android.app.admin.DeviceAdminReceiver} class
398consists of a series of callbacks that are triggered when particular events
399occur.</p>
400<p>In its {@link android.app.admin.DeviceAdminReceiver} subclass, the sample application
401simply displays a {@link android.widget.Toast} notification in response to particular
402events. For example:</p>
403<pre>public class DeviceAdminSample extends DeviceAdminReceiver {
404
405    void showToast(Context context, String msg) {
406        String status = context.getString(R.string.admin_receiver_status, msg);
407        Toast.makeText(context, status, Toast.LENGTH_SHORT).show();
408    }
409
410    &#64;Override
411    public void onEnabled(Context context, Intent intent) {
412        showToast(context, context.getString(R.string.admin_receiver_status_enabled));
413    }
414
415    &#64;Override
416    public CharSequence onDisableRequested(Context context, Intent intent) {
417        return context.getString(R.string.admin_receiver_status_disable_warning);
418    }
419
420    &#64;Override
421    public void onDisabled(Context context, Intent intent) {
422        showToast(context, context.getString(R.string.admin_receiver_status_disabled));
423    }
424
425    &#64;Override
426    public void onPasswordChanged(Context context, Intent intent) {
427        showToast(context, context.getString(R.string.admin_receiver_status_pw_changed));
428    }
429...
430}</pre>
431
432
433<h4 id="enabling">Enabling the application</h4>
434<p>One of the major events a device admin application has to handle is the user
435enabling the application. The user must explicitly enable the application for
436the policies to be enforced. If the user chooses not to enable the application
437it will still be present on the device, but its policies will not be enforced, and the user will not
438get any of the application's benefits.</p>
439<p>The process of enabling the application begins when the user performs an
440action that triggers the {@link android.app.admin.DevicePolicyManager#ACTION_ADD_DEVICE_ADMIN}
441intent. In the
442sample application, this happens when the user clicks the <strong>Enable
443Admin</strong> checkbox. </p>
444<p>When the user clicks the <strong>Enable Admin</strong> checkbox, the display
445changes to prompt the user to activate the device admin application, as shown in figure
4462.</p>
447
448<img src="{@docRoot}images/admin/device-admin-activate-prompt.png"/>
449<p class="img-caption"><strong>Figure 2.</strong> Sample Application: Activating the Application</p>
450
451<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 
452{@link android.preference.Preference.OnPreferenceChangeListener#onPreferenceChange(android.preference.Preference, java.lang.Object) onPreferenceChange()} 
453callback. 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
454changes to prompt the user to activate the device admin application, as shown in figure
4552. Otherwise, the device admin application is disabled. </p>
456
457<pre>&#64;Override
458        public boolean onPreferenceChange(Preference preference, Object newValue) {
459            if (super.onPreferenceChange(preference, newValue)) {
460                return true;
461            }
462            boolean value = (Boolean) newValue;
463            if (preference == mEnableCheckbox) {
464                if (value != mAdminActive) {
465                    if (value) {
466                        // Launch the activity to have the user enable our admin.
467                        Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
468                        intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, mDeviceAdminSample);
469                        intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,
470                                mActivity.getString(R.string.add_admin_extra_app_text));
471                        startActivityForResult(intent, REQUEST_CODE_ENABLE_ADMIN);
472                        // return false - don't update checkbox until we're really active
473                        return false;
474                    } else {
475                        mDPM.removeActiveAdmin(mDeviceAdminSample);
476                        enableDeviceCapabilitiesArea(false);
477                        mAdminActive = false;
478                    }
479                }
480            } else if (preference == mDisableCameraCheckbox) {
481                mDPM.setCameraDisabled(mDeviceAdminSample, value);
482                ...
483            }
484            return true;
485        }</pre>
486
487
488<p>The line
489<code>intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,
490mDeviceAdminSample)</code> states that <code>mDeviceAdminSample</code> (which is
491a {@link android.app.admin.DeviceAdminReceiver} component) is the target policy.
492This line invokes the user interface shown in figure 2, which guides users through
493adding the device administrator to the system (or allows them to reject it).</p>
494
495<p>When the application needs to perform an operation that is contingent on the
496device admin application being enabled, it confirms that the application is
497active. To do this it uses the {@link android.app.admin.DevicePolicyManager} method
498{@link android.app.admin.DevicePolicyManager#isAdminActive(android.content.ComponentName) isAdminActive()}. Notice that the {@link android.app.admin.DevicePolicyManager}
499method {@link android.app.admin.DevicePolicyManager#isAdminActive(android.content.ComponentName) isAdminActive()} takes a {@link android.app.admin.DeviceAdminReceiver}
500component as its argument:</p>
501
502<pre>
503DevicePolicyManager mDPM;
504...
505private boolean isActiveAdmin() {
506    return mDPM.isAdminActive(mDeviceAdminSample);
507}
508</pre>
509
510
511
512<h3 id="admin_ops">Managing policies</h3>
513<p>{@link android.app.admin.DevicePolicyManager} is a public class for managing policies
514enforced on a device. {@link android.app.admin.DevicePolicyManager} manages policies for one
515or more {@link android.app.admin.DeviceAdminReceiver} instances. </p>
516<p>You get a handle to the {@link android.app.admin.DevicePolicyManager} as follows: </p>
517<pre>
518DevicePolicyManager mDPM =
519    (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
520</pre>
521<p>This section describes how to use {@link android.app.admin.DevicePolicyManager} to perform
522 administrative tasks:</p>
523<ul>
524  <li><a href="#pwd">Set password policies</a></li>
525  <li><a href="#lock">Set  device lock</a></li>
526  <li><a href="#wipe">Perform data wipe</a></li>
527</ul>
528
529<h4 id="pwd">Set password policies</h4>
530<p>{@link android.app.admin.DevicePolicyManager} includes APIs for setting and enforcing the
531device password policy. In the Device Administration API, the password only applies to
532screen lock. This section describes common password-related tasks.</p>
533
534<h5>Set a password for the device</h5>
535<p>This code displays a user interface prompting the user to set a password:</p>
536<pre>Intent intent = new Intent(DevicePolicyManager.ACTION_SET_NEW_PASSWORD);
537startActivity(intent);
538</pre>
539
540<h5>Set the password quality</h5>
541<p>The password quality can be one of the following {@link android.app.admin.DevicePolicyManager} constants: </p>
542<dl>
543  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_ALPHABETIC}</dt><dd>The user must enter a
544password containing at least alphabetic (or other symbol) characters.</dd>
545  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_ALPHANUMERIC}</dt><dd>The user must enter a
546password containing at least <em>both</em> numeric <em>and</em> alphabetic (or
547other symbol) characters.</dd>
548  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_NUMERIC}</dt><dd>The user must enter a   password
549containing at least numeric characters.</dd>
550<dt>{@link
551android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_COMPLEX}</dt><dd>The user
552must have entered a password containing at least a letter, a numerical digit and
553a special symbol.</dd> 
554<dt>{@link
555android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_SOMETHING}</dt><dd>The
556policy requires some kind
557of password, but doesn't care what it is.</dd>
558  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_UNSPECIFIED}</dt><dd>
559  The policy has no requirements   for the password. </dd>
560</dl>
561<p>For example, this is how you would set the password policy to require an alphanumeric password:</p>
562<pre>
563DevicePolicyManager mDPM;
564ComponentName mDeviceAdminSample;
565...
566mDPM.setPasswordQuality(mDeviceAdminSample, DevicePolicyManager.PASSWORD_QUALITY_ALPHANUMERIC);
567</pre>
568
569<h5>Set password content requirements</h5>
570
571<p>Beginning with Android 3.0, the {@link android.app.admin.DevicePolicyManager} class
572includes methods that let you fine-tune the contents of the password. For
573example, you could set a policy that states that passwords must contain at least
574<em>n</em> uppercase letters. Here are the methods for fine-tuning a password's
575contents:</p>
576<ul>
577
578<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumLetters(android.content.ComponentName,int) setPasswordMinimumLetters()}</li> 
579
580<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumLowerCase(android.content.ComponentName,int) setPasswordMinimumLowerCase()}</li>
581
582<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumUpperCase(android.content.ComponentName,int) setPasswordMinimumUpperCase()}</li>
583
584<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumNonLetter(android.content.ComponentName,int) setPasswordMinimumNonLetter()}</li>
585
586<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumNumeric(android.content.ComponentName,int) setPasswordMinimumNumeric()}</li>
587
588<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumSymbols(android.content.ComponentName,int) setPasswordMinimumSymbols()}</li>
589</ul>
590<p>For example, this snippet states that the password must have at least 2 uppercase letters:</p>
591<pre>
592DevicePolicyManager mDPM;
593ComponentName mDeviceAdminSample;
594int pwMinUppercase = 2;
595...
596mDPM.setPasswordMinimumUpperCase(mDeviceAdminSample, pwMinUppercase);</pre>
597
598
599<h5>Set the minimum password length</h5>
600<p>You can specify that a password must be at least the specified minimum
601length. For example:</p>
602<pre>DevicePolicyManager mDPM;
603ComponentName mDeviceAdminSample;
604int pwLength;
605...
606mDPM.setPasswordMinimumLength(mDeviceAdminSample, pwLength);
607</pre>
608
609<h5>Set maximum failed password attempts</h5>
610<p>You can set the maximum number of allowed failed password attempts before the
611device is wiped (that is, reset to factory settings). For example:</p>
612<pre>DevicePolicyManager mDPM;
613ComponentName mDeviceAdminSample;
614int maxFailedPw;
615 ...
616mDPM.setMaximumFailedPasswordsForWipe(mDeviceAdminSample, maxFailedPw);</pre>
617
618<h5 id="expiration">Set password expiration timeout</h5>
619<p>Beginning with Android 3.0, you can use the 
620{@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()} 
621method 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>
622
623<pre>DevicePolicyManager mDPM;
624ComponentName mDeviceAdminSample;
625long pwExpiration;
626...
627mDPM.setPasswordExpirationTimeout(mDeviceAdminSample, pwExpiration);
628</pre>
629    
630<h5 id="history">Restrict password based on history</h5>
631
632<p>Beginning with Android 3.0, you can use the 
633{@link android.app.admin.DevicePolicyManager#setPasswordHistoryLength(android.content.ComponentName,int) setPasswordHistoryLength()} 
634method to limit users'
635ability to reuse old passwords. This method takes a <em>length</em>
636parameter, which specifies how many old
637passwords are stored. When this policy is active, users cannot enter a new
638password that matches the last <em>n</em> passwords. This prevents
639users from using the same password over and over. This policy is typically used
640in conjunction with 
641{@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()},
642which forces users
643to update their passwords after a specified amount of time has elapsed. </p>
644
645<p>For example, this snippet prohibits users from reusing any of their last 5 passwords:</p>
646
647<pre>DevicePolicyManager mDPM;
648ComponentName mDeviceAdminSample;
649int pwHistoryLength = 5;
650...
651mDPM.setPasswordHistoryLength(mDeviceAdminSample, pwHistoryLength);
652</pre>
653
654<h4 id="lock">Set device lock</h4>
655<p>You can set the maximum period of user inactivity that can occur before the
656device locks. For example:</p>
657<pre>
658DevicePolicyManager mDPM;
659ComponentName mDeviceAdminSample;
660...
661long timeMs = 1000L*Long.parseLong(mTimeout.getText().toString());
662mDPM.setMaximumTimeToLock(mDeviceAdminSample, timeMs);
663</pre>
664<p>You can also programmatically tell the device to lock immediately:</p>
665<pre>
666DevicePolicyManager mDPM;
667mDPM.lockNow();
668</pre>
669
670
671
672<h4 id="wipe">Perform data wipe</h4>
673
674<p>You can use the {@link android.app.admin.DevicePolicyManager} method
675{@link android.app.admin.DevicePolicyManager#wipeData wipeData()} to reset the device to factory settings. This is useful
676if the device is lost or stolen. Often the decision to wipe the device is the
677result of certain conditions being met. For example, you can use
678{@link android.app.admin.DevicePolicyManager#setMaximumFailedPasswordsForWipe setMaximumFailedPasswordsForWipe()} to state that a device should be
679wiped after a specific number of failed password attempts.</p>
680<p>You wipe data as follows:</p>
681<pre>
682DevicePolicyManager mDPM;
683mDPM.wipeData(0);</pre>
684<p>The {@link android.app.admin.DevicePolicyManager#wipeData wipeData()} method takes as its
685  parameter a bit mask of additional options. Currently the value must be 0. </p>
686
687<h4>Disable camera</h4>
688<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>
689<p>You control whether the camera is disabled by using the
690{@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>
691
692<pre>private CheckBoxPreference mDisableCameraCheckbox;
693DevicePolicyManager mDPM;
694ComponentName mDeviceAdminSample;
695...
696mDPM.setCameraDisabled(mDeviceAdminSample, mDisableCameraCheckbox.isChecked());<br />
697</pre>
698
699
700<h4 id="storage">Storage encryption</h4>
701<p>Beginning with Android 3.0, you can use the
702{@link android.app.admin.DevicePolicyManager#setStorageEncryption(android.content.ComponentName,boolean) setStorageEncryption()} 
703method to set a policy requiring encryption of the storage area, where supported.</p>
704
705<p>For example:</p>
706
707<pre>
708DevicePolicyManager mDPM;
709ComponentName mDeviceAdminSample;
710...
711mDPM.setStorageEncryption(mDeviceAdminSample, true);
712</pre>
713<p>
714See the Device Administration API sample for a complete example of how to enable storage encryption.
715</p>