Android Security Mechanism-four major component security

Android Security Mechanism-four major component security

The component has the concept of Public and Private, and whether the component can be called by other parties. The android: exported field is used to determine. android: exported = true indicates yes, but not vice versa.

By default, if the AndroidMainfest statement does not contain interfliter, the value of exported is false, and the value of interfliter is true. Of course, you can directly enter android: exported for your control. Set the value to false as follows:

[Html]

1. Android: name =. LoginActivity
2. Android: label = @ string/app_name
3. Android: screenOrientation = portrait
4. Android: exported = false>

   We can use custom permission to limit the security of the four major components.

   Activity

   In service

   Contentprovider has two permissions: write and read.

   When sending in broastreceiver

   Receiving

   How to customize it? In androidmainfest

    

   [Html]
   1. Android: label = test
   2. Android: name = com. test. custempermission
   3. Android: protectionLevel = normal>
   4. 
      

       

      Next, we will experiment by specifying a BroadcastReceiver permission.
      First, two apps, app A and app B, are created;
      App A registers A BroadcastReceiver and app B sends messages.
      Menifest file of app:

      Xml Code
      1. Package = com. example. testbutton
      2. Android: versionCode = 1
      3. Android: versionName = 1.0>
      4.  
      5. Android: minSdkVersion = 7
      6. Android: targetSdkVersion = 15/>
      9.  
      10. Android: icon = @ drawable/ic_launcher
      11. Android: label = @ string/app_name
      12. Android: theme = @ style/AppTheme>
      13. Android: name =. MainActivity
      14. LauncheMode = singleTask
      15. Android: configChanges = locale | orientation | keyboardHidden
      16. Android: screenOrientation = portrait
      17. Android: theme = @ style/android: style/Theme. NoTitleBar. Fullscreen>
      20.  
      22.  
      23.  
      25. Android: name = com. example. testbutton. TestButtonReceiver
      26. Android: permission = com. example. testbutton. RECEIVE>
      29.  
      30.  
      31.  
      32.  
      33. Menifest file content of app B
          Xml Code
          1. Package = com. example. testsender
          2. Android: versionCode = 1
          3. Android: versionName = 1.0>
          4.  
          5. Android: minSdkVersion = 7
          6. Android: targetSdkVersion = 15/>
          9.  
          10. Android: icon = @ drawable/ic_launcher
          11. Android: label = @ string/app_name
          12. Android: theme = @ style/AppTheme>
          13. Android: name =. MainActivity
          14. Android: label = @ string/title_activity_main>
          17.  
          19.  
          20.  
          21.  
          22.  
          23. In this way, app B sends A message to app A, and then A receives the message. If app B does not declare the corresponding permissions in the menifest file of app B, app B sends the message, A cannot.