device-admin.jd revision 6c5951bf9798369d335096f1f73ee1299cf903ff
1page.title=Device Administration
2@jd:body
3
4<div id="qv-wrapper">
5<div id="qv">
6    <h2>In this document</h2>
7    <ol>
8<li><a href="#overview">Device Administration API Overview</a>
9    <ol>
10      <li><a href="#how">How does it work?</a></li>
11      <li><a href="#policies">Policies</a></li>
12    </ol>
13  </li>
14  <li><a href="#sample">Sample Application</a></li>
15  <li><a href="#developing">Developing a Device Administration Application</a>
16    <ol>
17      <li><a href="#manifest">Creating the manifest</a></li>
18      <li><a href="#code">Implementing the code</a></li>
19    </ol>
20  </li>
21
22 </ol>
23
24    <h2>Key classes</h2>
25    <ol>
26      <li>{@link android.app.admin.DeviceAdminReceiver}</li>
27      <li>{@link android.app.admin.DevicePolicyManager}</li>
28      <li>{@link android.app.admin.DeviceAdminInfo}</li>
29    </ol>
30    <h2>Related samples</h2>
31    <ol>
32      <li><a
33href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">
34DeviceAdminSample</a></li>
35</ol>
36</div>
37</div>
38
39<p>Android 2.2 introduces support for enterprise applications by offering the
40Android Device Administration API. The Device Administration API provides device
41administration features at the system level.  These APIs allow you to create
42security-aware applications that are useful in enterprise settings, in which IT
43professionals require rich control over employee devices. For example, the
44built-in Android Email application has leveraged the new APIs to improve
45Exchange support. Through the Email application, Exchange administrators can
46enforce password policies &mdash;  including alphanumeric passwords or numeric
47PINs &mdash; across devices. Administrators can also remotely wipe (that is,
48restore factory defaults on) lost or stolen handsets. Exchange users can sync
49their email and calendar data.</p>
50
51<p>This document is intended for developers who want to develop enterprise
52solutions for Android-powered devices. It discusses the various features
53provided by the Device Administration API to provide stronger security for
54employee devices that are powered by Android.</p>
55
56
57<h2 id="overview">Device Administration API Overview</h2>
58
59<p>Here are examples of the types of applications that might use the Device Administration API:</p>
60<ul>
61  <li>Email clients.</li>
62  <li>Security applications that do remote wipe.</li>
63  <li>Device management services and applications.</li>
64</ul>
65
66<h3 id="how">How does it work?</h3>
67<p>You use the Device Administration API to write device admin applications that users
68install on their devices. The device admin application enforces the desired
69policies. Here's how it works:</p> <ul>
70  <li>A system administrator writes a device admin application that enforces
71remote/local device security policies. These policies could be hard-coded into
72the app, or the application could dynamically fetch policies from a third-party
73server. </li>
74<li>The  application is installed on users' devices. Android does
75not currently have an automated provisioning solution. Some of the ways a sysadmin might
76distribute the application to users are as follows:
77<ul>
78<li>Android Market.</li>
79<li>Enabling non-market installation.</li>
80<li>Distributing the application through other means, such as email or websites.</li>
81
82</ul>
83
84
85</li>
86  <li>The system prompts the user to enable the device admin application. How
87and when this happens depends on how the application is implemented.</li>
88<li>Once  users enable the device admin application, they are subject to
89its policies. Complying with those policies typically confers benefits, such as
90access to sensitive systems and data.</li>
91</ul>
92<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>
93<p>If a user fails to comply with the policies (for example, if a user sets a
94password that violates the guidelines), it is up to the application to decide
95how to handle this. However, typically this will result in the user not being
96able to sync data.</p>
97<p>If a device attempts to connect to a server that requires policies not
98supported in the Device Administration API, the connection will not
99be allowed. The Device Administration API does not currently allow partial
100provisioning. In other words, if a device (for example, a legacy device) does
101not support all of the stated policies, there is no way to allow the
102device to connect.</p>
103<p>If a device contains multiple enabled admin applications, the strictest policy is
104enforced. There is no way to target a particular admin
105application.</p>
106<p>To uninstall an existing device admin application, users need to
107first unregister the application as an administrator. </p>
108
109
110<h3 id="policies">Policies</h3>
111
112<p>In an enterprise setting, it's often the case that employee devices must
113adhere to a strict set of policies that govern the use of the device. The
114Device Administration API supports the  policies listed in Table 1.
115Note that the Device Administration API currently only supports passwords for screen
116lock:</p>
117<p class="table-caption"><strong>Table 1.</strong> Policies supported by the Device Administration API.</p>
118<table border="1">
119  <tr>
120    <th>Policy</th>
121    <th>Description</th>
122  </tr>
123  <tr>
124    <td>Password enabled</td>
125    <td>Requires that devices ask for PIN or passwords.</td>
126  </tr>
127  <tr>
128    <td>Minimum password length</td>
129    <td>Set the required number of characters for the password. For example, you
130can require PIN or passwords to have at least six characters. </td> </tr>
131  <tr>
132    <td>Alphanumeric password required</td>
133    <td>Requires that passwords have a
134combination of letters and numbers. They may include symbolic characters.
135    </td>
136  </tr>
137  
138  <tr>
139    <td>Complex password required</td>
140    <td>Requires that passwords must contain at least a letter, a numerical digit, and a special symbol. Introduced in Android 3.0.
141    </td>
142  </tr>
143  
144<tr> 
145  <td>Minimum letters required in password</td> <td>The minimum number of
146letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
147</tr>
148  
149  
150  <tr> 
151  <td>Minimum lowercase letters required in password</td> 
152  <td>The minimum number of lowercase 
153letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
154</tr>
155  
156  <tr> 
157  <td>Minimum non-letter characters required in password</td> 
158  <td>The minimum number of
159non-letter characters 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 numerical digits required in password</td> 
164  <td>The minimum number of numerical digits 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 symbols required in password</td> 
169  <td>The minimum number of symbols required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
170</tr>
171
172<tr> 
173  <td>Minimum uppercase letters required in password</td> 
174  <td>The minimum number of uppercase letters required in the password for all admins or a particular one. Introduced in Android 3.0.</td> 
175</tr>
176
177<tr> 
178  <td>Password expiration timeout</td> 
179  <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> 
180</tr>
181
182<tr> 
183  <td>Password history restriction</td> 
184  <td>This policy prevents users from reusing the last <em>n</em> unique passwords.
185 This policy is typically used in conjunction with
186{@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()}, which forces
187users to update their passwords after a specified amount of time has elapsed.
188Introduced in Android 3.0.</td> 
189</tr>
190  
191  <tr>
192    <td>Maximum failed password attempts </td>
193    <td>Specifies how many times a user can enter the wrong password before the
194device wipes its data.  The Device Administration API also allows administrators to
195remotely reset the device to  factory defaults. This secures data in case the
196device is lost or stolen.</td>
197  </tr>
198  <tr>
199    <td>Maximum inactivity time lock</td>
200    <td>Sets the length of time since the user last touched the screen or
201pressed a button before the device locks the screen. When this happens, users
202need to enter their PIN or passwords again before they can use their devices and
203access data.  The value can be between 1 and 60 minutes.</td> </tr>
204
205<tr> 
206<td>Require storage encryption</td> 
207<td>Specifies that the storage area should be encrypted, if the device supports it. 
208Introduced in Android 3.0.</td> </tr>
209
210<tr>
211  <td>Disable camera</td>
212  
213  <td>Specifies that the camera should be disabled. Note that this doesn't have
214to be a permanent disabling. The camera can be enabled/disabled dynamically
215based on context, time, and so on. Introduced in Android 4.0.</td>
216  
217</tr>
218
219
220</table>
221
222<h4>Other features</h4>
223
224<p>In addition to supporting the policies listed in the above table, the Device
225Administration API lets you do the following:</p> <ul>
226  <li>Prompt user to set a new password.</li>
227  <li>Lock device immediately.</li>
228  <li>Wipe the device's data (that is, restore the device to its factory defaults).</li>
229</ul>
230
231
232<h2 id="sample">Sample Application</h2>
233
234<p>The examples used in this document are based on the <a
235href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">
236Device Administration API
237sample</a>, which is included in the SDK samples. For information on downloading and
238installing the SDK samples, see <a
239href="{@docRoot}resources/samples/get.html">
240Getting the Samples</a>. Here is the  <a
241href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html">
242complete code</a> for
243the sample. </p>
244<p>The
245sample application offers a demo of device admin features. It presents users
246with a user interface that lets them enable the device admin application. Once
247they've enabled the application, they can use the buttons in the user interface
248to do the following:</p>
249<ul>
250  <li>Set password quality.</li>
251  <li>Specify requirements for the user's password, such as minimum length, the minimum number of
252  numeric characters it must contain, and so on.</li>
253  <li>Set the password. If the password does not conform to the specified
254policies, the system  returns an error.</li>
255  <li>Set how many failed password attempts can occur before the device is wiped
256(that is, restored to factory settings).</li>
257<li>Set how long from now the password will expire.</li>
258<li>Set the password history length (<em>length</em> refers to number of old passwords stored in the history). 
259This prevents users from reusing 
260one of the last <em>n</em> passwords they previously used.</li>
261<li>Specify that the storage area should be encrypted, if the device supports it.</li>
262  <li>Set the maximum amount of inactive time that can elapse before the device
263locks.</li>
264  <li>Make the device lock immediately.</li>
265  <li>Wipe the device's data (that is, restore factory settings).</li>
266  <li>Disable the camera.</li>
267  
268</ul>
269
270
271
272<img src="{@docRoot}images/admin/device-admin-app.png"/>
273
274<p class="img-caption"><strong>Figure 1.</strong> Screenshot of the Sample Application</p>
275
276
277
278<h2 id="developing">Developing a Device Administration Application</h2>
279
280<p>System administrators can use the Device Administration API to write an application
281that enforces remote/local device security policy enforcement. This section
282summarizes the steps involved in creating a device administration
283application.</p>
284
285<h3 id="manifest">Creating the manifest</h3>
286
287<p>To use the Device Administration API, the application's
288manifest must include the following:</p>
289<ul>
290  <li>A subclass of {@link android.app.admin.DeviceAdminReceiver} that includes the following:
291    <ul>
292      <li>The {@link android.Manifest.permission#BIND_DEVICE_ADMIN} permission.</li>
293      <li>The ability to  respond to the {@link android.app.admin.DeviceAdminReceiver#ACTION_DEVICE_ADMIN_ENABLED}
294intent, expressed in the manifest as an intent filter.</li>
295    </ul>
296  </li>
297  <li>A declaration of security policies used in metadata.</li>
298</ul>
299<p>Here is an excerpt from the Device Administration sample manifest:</p>
300<pre>&lt;activity android:name=&quot;.app.DeviceAdminSample&quot;
301            android:label=&quot;&#64;string/activity_sample_device_admin&quot;&gt;
302    &lt;intent-filter&gt;
303        &lt;action android:name=&quot;android.intent.action.MAIN&quot; /&gt;
304        &lt;category android:name=&quot;android.intent.category.SAMPLE_CODE&quot; /&gt;
305    &lt;/intent-filter&gt;
306&lt;/activity&gt;
307&lt;receiver android:name=&quot;.app.DeviceAdminSample$DeviceAdminSampleReceiver&quot;
308        android:label=&quot;&#64;string/sample_device_admin&quot;
309        android:description=&quot;&#64;string/sample_device_admin_description&quot;
310        android:permission=&quot;android.permission.BIND_DEVICE_ADMIN&quot;&gt;
311    &lt;meta-data android:name=&quot;android.app.device_admin&quot;
312            android:resource=&quot;&#64;xml/device_admin_sample&quot; /&gt;
313    &lt;intent-filter&gt;
314        &lt;action android:name=&quot;android.app.action.DEVICE_ADMIN_ENABLED&quot; /&gt;
315    &lt;/intent-filter&gt;
316&lt;/receiver&gt;</pre>
317
318 <p>Note that:</p>
319<ul>
320<li>The following attributes refer to string resources that for the sample application reside in
321<code>ApiDemos/res/values/strings.xml</code>. For more information about resources, see
322<a
323href="{@docRoot}guide/topics/resources/index.html">Application Resources</a>.
324<ul>
325<li><code>android:label=&quot;&#64;string/activity_sample_device_admin&quot;</code> refers to the
326user-readable label for the activity.</li>
327
328<li><code>android:label=&quot;&#64;string/sample_device_admin&quot;</code> refers to the
329user-readable label for the permission.</li>
330
331<li><code>android:description=&quot;&#64;string/sample_device_admin_description&quot;</code> refers to
332the user-readable description of the permission. A descripton is typically longer and more
333informative than
334a label.</li>
335</ul>
336
337
338<li><code>android:permission=&quot;android.permission.BIND_DEVICE_ADMIN&quot;
339</code> is a permission that a {@link android.app.admin.DeviceAdminReceiver} subclass must
340have, to ensure that only the system can interact with the receiver (no application can be granted this permission). This
341prevents other applications from abusing your device admin app.</li>
342<li><code>android.app.action.DEVICE_ADMIN_ENABLED</code> is the  the primary
343action that a {@link android.app.admin.DeviceAdminReceiver} subclass must handle to be
344allowed to manage a device. This is set to the receiver when the user enables
345the device admin app. Your code typically handles this in
346{@link android.app.admin.DeviceAdminReceiver#onEnabled onEnabled()}. To be supported, the receiver must also
347require the {@link android.Manifest.permission#BIND_DEVICE_ADMIN} permission so that other applications
348cannot abuse it.  </li>
349<li>When a user enables the device admin application, that gives the receiver
350permission to perform actions in response to the broadcast of particular system
351events. When suitable event arises, the application can impose a policy. For
352example, if the user attempts to set a new password that doesn't meet the policy
353requirements, the application can prompt the user to pick a different password
354that does meet the requirements.</li>
355
356  <li><code>android:resource=&quot;&#64;xml/device_admin_sample&quot;</code>
357declares the security policies used in metadata. The metadata provides additional
358information specific to the device administrator, as parsed by the {@link
359android.app.admin.DeviceAdminInfo} class. Here are the contents of
360<code>device_admin_sample.xml</code>:</li>
361</ul>
362<pre>&lt;device-admin xmlns:android=&quot;http://schemas.android.com/apk/res/android">;
363  &lt;uses-policies&gt;
364    &lt;limit-password /&gt;
365    &lt;watch-login /&gt;
366    &lt;reset-password /&gt;
367    &lt;force-lock /&gt;
368    &lt;wipe-data /&gt;
369    &lt;expire-password /&gt;
370    &lt;encrypted-storage /&gt;
371    &lt;disable-camera /&gt;
372  &lt;/uses-policies&gt;
373&lt;/device-admin&gt;
374</pre>
375<p> In designing your device administration application, you don't need to
376include all of the policies, just the ones that are relevant for your app.
377</p>
378For more discussion of the manifest file, see the <a
379href="{@docRoot}guide/topics/manifest/manifest-intro.html">Android Developers Guide</a>.
380
381
382
383<h3 id="code">Implementing the code</h3>
384
385<p>The Device Administration API includes the following classes:</p>
386<dl>
387  <dt>{@link android.app.admin.DeviceAdminReceiver}</dt>
388     <dd>Base class for implementing a device administration component. This class provides
389a convenience for interpreting the raw intent actions   that are sent by the
390system. Your Device Administration application must include a
391{@link android.app.admin.DeviceAdminReceiver} subclass.</dd>
392  <dt>{@link android.app.admin.DevicePolicyManager}</dt>
393<dd>A class for managing policies enforced on a device. Most clients of
394this class must have published a {@link android.app.admin.DeviceAdminReceiver} that the user
395has currently enabled. The {@link android.app.admin.DevicePolicyManager} manages policies for
396one or more {@link android.app.admin.DeviceAdminReceiver} instances</dd>
397  <dt>{@link android.app.admin.DeviceAdminInfo}</dt>
398<dd>This class is used to specify metadata
399for a device administrator component.</dd>
400</dl>
401<p>These classes provide the foundation for a fully functional device administration application.
402The rest of this section describes how you use the {@link
403android.app.admin.DeviceAdminReceiver} and
404{@link android.app.admin.DevicePolicyManager} APIs to write a device admin application.</p>
405
406<h4 id="receiver">Subclassing DeviceAdminReceiver</h4>
407<p>To create a device admin application, you must subclass
408{@link android.app.admin.DeviceAdminReceiver}. The {@link android.app.admin.DeviceAdminReceiver} class
409consists of a series of callbacks that are triggered when particular events
410occur.</p>
411<p>In its {@link android.app.admin.DeviceAdminReceiver} subclass, the sample application
412simply displays a {@link android.widget.Toast} notification in response to particular
413events. For example:</p>
414<pre>public class DeviceAdminSample extends DeviceAdminReceiver {
415
416    void showToast(Context context, String msg) {
417        String status = context.getString(R.string.admin_receiver_status, msg);
418        Toast.makeText(context, status, Toast.LENGTH_SHORT).show();
419    }
420
421    &#64;Override
422    public void onEnabled(Context context, Intent intent) {
423        showToast(context, context.getString(R.string.admin_receiver_status_enabled));
424    }
425
426    &#64;Override
427    public CharSequence onDisableRequested(Context context, Intent intent) {
428        return context.getString(R.string.admin_receiver_status_disable_warning);
429    }
430
431    &#64;Override
432    public void onDisabled(Context context, Intent intent) {
433        showToast(context, context.getString(R.string.admin_receiver_status_disabled));
434    }
435
436    &#64;Override
437    public void onPasswordChanged(Context context, Intent intent) {
438        showToast(context, context.getString(R.string.admin_receiver_status_pw_changed));
439    }
440...
441}</pre>
442
443
444<h4 id="enabling">Enabling the application</h4>
445<p>One of the major events a device admin application has to handle is the user
446enabling the application. The user must explicitly enable the application for
447the policies to be enforced. If the user chooses not to enable the application
448it will still be present on the device, but its policies will not be enforced, and the user will not
449get any of the application's benefits.</p>
450<p>The process of enabling the application begins when the user performs an
451action that triggers the {@link android.app.admin.DevicePolicyManager#ACTION_ADD_DEVICE_ADMIN}
452intent. In the
453sample application, this happens when the user clicks the <strong>Enable
454Admin</strong> checkbox. </p>
455<p>When the user clicks the <strong>Enable Admin</strong> checkbox, the display
456changes to prompt the user to activate the device admin application, as shown in figure
4572.</p>
458
459<img src="{@docRoot}images/admin/device-admin-activate-prompt.png"/>
460<p class="img-caption"><strong>Figure 2.</strong> Sample Application: Activating the Application</p>
461
462<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 
463{@link android.preference.Preference.OnPreferenceChangeListener#onPreferenceChange(android.preference.Preference, java.lang.Object) onPreferenceChange()} 
464callback. 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
465changes to prompt the user to activate the device admin application, as shown in figure
4662. Otherwise, the device admin application is disabled. </p>
467
468<pre>&#64;Override
469        public boolean onPreferenceChange(Preference preference, Object newValue) {
470            if (super.onPreferenceChange(preference, newValue)) {
471                return true;
472            }
473            boolean value = (Boolean) newValue;
474            if (preference == mEnableCheckbox) {
475                if (value != mAdminActive) {
476                    if (value) {
477                        // Launch the activity to have the user enable our admin.
478                        Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
479                        intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, mDeviceAdminSample);
480                        intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,
481                                mActivity.getString(R.string.add_admin_extra_app_text));
482                        startActivityForResult(intent, REQUEST_CODE_ENABLE_ADMIN);
483                        // return false - don't update checkbox until we're really active
484                        return false;
485                    } else {
486                        mDPM.removeActiveAdmin(mDeviceAdminSample);
487                        enableDeviceCapabilitiesArea(false);
488                        mAdminActive = false;
489                    }
490                }
491            } else if (preference == mDisableCameraCheckbox) {
492                mDPM.setCameraDisabled(mDeviceAdminSample, value);
493                ...
494            }
495            return true;
496        }</pre>
497
498
499<p>The line
500<code>intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,
501mDeviceAdminSample)</code> states that <code>mDeviceAdminSample</code> (which is
502a {@link android.app.admin.DeviceAdminReceiver} component) is the target policy.
503This line invokes the user interface shown in figure 2, which guides users through
504adding the device administrator to the system (or allows them to reject it).</p>
505
506<p>When the application needs to perform an operation that is contingent on the
507device admin application being enabled, it confirms that the application is
508active. To do this it uses the {@link android.app.admin.DevicePolicyManager} method
509{@link android.app.admin.DevicePolicyManager#isAdminActive(android.content.ComponentName) isAdminActive()}. Notice that the {@link android.app.admin.DevicePolicyManager}
510method {@link android.app.admin.DevicePolicyManager#isAdminActive(android.content.ComponentName) isAdminActive()} takes a {@link android.app.admin.DeviceAdminReceiver}
511component as its argument:</p>
512
513<pre>
514DevicePolicyManager mDPM;
515...
516private boolean isActiveAdmin() {
517    return mDPM.isAdminActive(mDeviceAdminSample);
518}
519</pre>
520
521
522
523<h3 id="admin_ops">Managing policies</h3>
524<p>{@link android.app.admin.DevicePolicyManager} is a public class for managing policies
525enforced on a device. {@link android.app.admin.DevicePolicyManager} manages policies for one
526or more {@link android.app.admin.DeviceAdminReceiver} instances. </p>
527<p>You get a handle to the {@link android.app.admin.DevicePolicyManager} as follows: </p>
528<pre>
529DevicePolicyManager mDPM =
530    (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);
531</pre>
532<p>This section describes how to use {@link android.app.admin.DevicePolicyManager} to perform
533 administrative tasks:</p>
534<ul>
535  <li><a href="#pwd">Set password policies</a></li>
536  <li><a href="#lock">Set  device lock</a></li>
537  <li><a href="#wipe">Perform data wipe</a></li>
538</ul>
539
540<h4 id="pwd">Set password policies</h4>
541<p>{@link android.app.admin.DevicePolicyManager} includes APIs for setting and enforcing the
542device password policy. In the Device Administration API, the password only applies to
543screen lock. This section describes common password-related tasks.</p>
544
545<h5>Set a password for the device</h5>
546<p>This code displays a user interface prompting the user to set a password:</p>
547<pre>Intent intent = new Intent(DevicePolicyManager.ACTION_SET_NEW_PASSWORD);
548startActivity(intent);
549</pre>
550
551<h5>Set the password quality</h5>
552<p>The password quality can be one of the following {@link android.app.admin.DevicePolicyManager} constants: </p>
553<dl>
554  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_ALPHABETIC}</dt><dd>The user must enter a
555password containing at least alphabetic (or other symbol) characters.</dd>
556  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_ALPHANUMERIC}</dt><dd>The user must enter a
557password containing at least <em>both</em> numeric <em>and</em> alphabetic (or
558other symbol) characters.</dd>
559  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_NUMERIC}</dt><dd>The user must enter a   password
560containing at least numeric characters.</dd>
561<dt>{@link
562android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_COMPLEX}</dt><dd>The user
563must have entered a password containing at least a letter, a numerical digit and
564a special symbol.</dd> 
565<dt>{@link
566android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_SOMETHING}</dt><dd>The
567policy requires some kind
568of password, but doesn't care what it is.</dd>
569  <dt>{@link android.app.admin.DevicePolicyManager#PASSWORD_QUALITY_UNSPECIFIED}</dt><dd>
570  The policy has no requirements   for the password. </dd>
571</dl>
572<p>For example, this is how you would set the password policy to require an alphanumeric password:</p>
573<pre>
574DevicePolicyManager mDPM;
575ComponentName mDeviceAdminSample;
576...
577mDPM.setPasswordQuality(mDeviceAdminSample, DevicePolicyManager.PASSWORD_QUALITY_ALPHANUMERIC);
578</pre>
579
580<h5>Set password content requirements</h5>
581
582<p>Beginning with Android 3.0, the {@link android.app.admin.DevicePolicyManager} class
583includes methods that let you fine-tune the contents of the password. For
584example, you could set a policy that states that passwords must contain at least
585<em>n</em> uppercase letters. Here are the methods for fine-tuning a password's
586contents:</p>
587<ul>
588
589<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumLetters(android.content.ComponentName,int) setPasswordMinimumLetters()}</li> 
590
591<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumLowerCase(android.content.ComponentName,int) setPasswordMinimumLowerCase()}</li>
592
593<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumUpperCase(android.content.ComponentName,int) setPasswordMinimumUpperCase()}</li>
594
595<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumNonLetter(android.content.ComponentName,int) setPasswordMinimumNonLetter()}</li>
596
597<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumNumeric(android.content.ComponentName,int) setPasswordMinimumNumeric()}</li>
598
599<li>{@link android.app.admin.DevicePolicyManager#setPasswordMinimumSymbols(android.content.ComponentName,int) setPasswordMinimumSymbols()}</li>
600</ul>
601<p>For example, this snippet states that the password must have at least 2 uppercase letters:</p>
602<pre>
603DevicePolicyManager mDPM;
604ComponentName mDeviceAdminSample;
605int pwMinUppercase = 2;
606...
607mDPM.setPasswordMinimumUpperCase(mDeviceAdminSample, pwMinUppercase);</pre>
608
609
610<h5>Set the minimum password length</h5>
611<p>You can specify that a password must be at least the specified minimum
612length. For example:</p>
613<pre>DevicePolicyManager mDPM;
614ComponentName mDeviceAdminSample;
615int pwLength;
616...
617mDPM.setPasswordMinimumLength(mDeviceAdminSample, pwLength);
618</pre>
619
620<h5>Set maximum failed password attempts</h5>
621<p>You can set the maximum number of allowed failed password attempts before the
622device is wiped (that is, reset to factory settings). For example:</p>
623<pre>DevicePolicyManager mDPM;
624ComponentName mDeviceAdminSample;
625int maxFailedPw;
626 ...
627mDPM.setMaximumFailedPasswordsForWipe(mDeviceAdminSample, maxFailedPw);</pre>
628
629<h5 id="expiration">Set password expiration timeout</h5>
630<p>Beginning with Android 3.0, you can use the 
631{@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()} 
632method 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>
633
634<pre>DevicePolicyManager mDPM;
635ComponentName mDeviceAdminSample;
636long pwExpiration;
637...
638mDPM.setPasswordExpirationTimeout(mDeviceAdminSample, pwExpiration);
639</pre>
640    
641<h5 id="history">Restrict password based on history</h5>
642
643<p>Beginning with Android 3.0, you can use the 
644{@link android.app.admin.DevicePolicyManager#setPasswordHistoryLength(android.content.ComponentName,int) setPasswordHistoryLength()} 
645method to limit users'
646ability to reuse old passwords. This method takes a <em>length</em>
647parameter, which specifies how many old
648passwords are stored. When this policy is active, users cannot enter a new
649password that matches the last <em>n</em> passwords. This prevents
650users from using the same password over and over. This policy is typically used
651in conjunction with 
652{@link android.app.admin.DevicePolicyManager#setPasswordExpirationTimeout(android.content.ComponentName,long) setPasswordExpirationTimeout()},
653which forces users
654to update their passwords after a specified amount of time has elapsed. </p>
655
656<p>For example, this snippet prohibits users from reusing any of their last 5 passwords:</p>
657
658<pre>DevicePolicyManager mDPM;
659ComponentName mDeviceAdminSample;
660int pwHistoryLength = 5;
661...
662mDPM.setPasswordHistoryLength(mDeviceAdminSample, pwHistoryLength);
663</pre>
664
665<h4 id="lock">Set device lock</h4>
666<p>You can set the maximum period of user inactivity that can occur before the
667device locks. For example:</p>
668<pre>
669DevicePolicyManager mDPM;
670ComponentName mDeviceAdminSample;
671...
672long timeMs = 1000L*Long.parseLong(mTimeout.getText().toString());
673mDPM.setMaximumTimeToLock(mDeviceAdminSample, timeMs);
674</pre>
675<p>You can also programmatically tell the device to lock immediately:</p>
676<pre>
677DevicePolicyManager mDPM;
678mDPM.lockNow();</pre>
679
680
681
682<h4 id="wipe">Perform data wipe</h4>
683
684<p>You can use the {@link android.app.admin.DevicePolicyManager} method
685{@link android.app.admin.DevicePolicyManager#wipeData wipeData()} to reset the device to factory settings. This is useful
686if the device is lost or stolen. Often the decision to wipe the device is the
687result of certain conditions being met. For example, you can use
688{@link android.app.admin.DevicePolicyManager#setMaximumFailedPasswordsForWipe setMaximumFailedPasswordsForWipe()} to state that a device should be
689wiped after a specific number of failed password attempts.</p>
690<p>You wipe data as follows:</p>
691<pre>
692DevicePolicyManager mDPM;
693mDPM.wipeData(0);</pre>
694<p>The {@link android.app.admin.DevicePolicyManager#wipeData wipeData()} method takes as its parameter a bit mask of
695additional options. Currently the value must be 0. </p>
696
697<h4>Disable camera</h4>
698<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>
699<p>You control whether the camera is disabled by using the 
700{@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>
701
702<pre>private CheckBoxPreference mDisableCameraCheckbox;
703DevicePolicyManager mDPM;
704ComponentName mDeviceAdminSample;
705...
706mDPM.setCameraDisabled(mDeviceAdminSample, mDisableCameraCheckbox.isChecked());<br />
707</pre>
708
709
710<h4 id=storage">Storage encryption</h4>
711<p>Beginning with Android 3.0, you can use the 
712{@link android.app.admin.DevicePolicyManager#setStorageEncryption(android.content.ComponentName,boolean) setStorageEncryption()} 
713method to set a policy requiring encryption of the storage area, where supported.</p>
714
715<p>For example:</p>
716
717<pre>
718DevicePolicyManager mDPM;
719ComponentName mDeviceAdminSample;
720...
721mDPM.setStorageEncryption(mDeviceAdminSample, true);
722</pre>
723<p>
724See the <a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/DeviceAdminSample.html"> Device Administration API sample</a> for a complete
725example of how to enable storage encryption.</p>
726