![20
Runtime Permission - Caller
• Always Check for Permissions
• Handle Lack of Permissions Gracefully
if (checkSelfPermission(Manifest.permission.READ_CONTACTS)
!= PackageManager.PERMISSION_GRANTED) {
if (shouldShowRequestPermissionRationale(
Manifest.permission.READ_CONTACTS)) {
}
requestPermissions(new
String[]{Manifest.permission.READ_CONTACTS},
MY_PERMISSIONS_REQUEST_READ_CONTACTS);
return;
}](https://image.slidesharecdn.com/androidsecuirty-permission-upload-160705140348/85/Android-secuirty-permission-upload-20-320.jpg)
Android secuirty permission - upload
- 1. 1 Android Security - Permission
- 2. 2 Agenda • What is permission • System prebuilt vs APK Custom • Request a permission • Grant permission • Enforce Permission • Runtime permission
- 3. 3 What is Permission • Applications (UIDs) are assigned permissions • Permissions are needed to control access to System resources (logs, battery, etc.) Sensitive data (SMS, contacts, e-mails, etc.) System interfaces (Internet, send SMS, etc.) • Application (developers) can also define own permissions to protect application interfaces • A string
- 4. 4 Permission Group Divide permissions into some groups based on functionality. In M, Permission is granted by group.
- 5. 5 Permission Level • Normal Lower-risk permission, auto grant in installation • Dangerous Higher-risk permission, Need user grant.(Runtime grant/revoke in M) • Signature Auto grant in installation if caller/callee are signed by same certification • SignatureOrSystem Auto grant in installation if caller/callee are signed by same certification or caller is in system image.
- 6. 6 System Prebuilt In frameworks/base/core/res/AndroidManifest.xml <permission android:name="android.permission.READ_CONTACTS" android:permissionGroup="android.permission-group.CONTACTS" android:label="@string/permlab_readContacts" android:description="@string/permdesc_readContacts" android:protectionLevel="dangerous" />
- 7. 7 APK Custom In AndroidManifest.xml of APK <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.myapp" > <permission android:name="com.example.app.DO_X" android:label="@string/do_x_label" android:description="@string/do_x_desc" android:permissionGroup="android.permission-group.PERSONAL_INFO" android:protectionLevel="dangerous" /> … </manifest>
- 8. 8 Permission Conflict Multiple applications may attempt to define the same permission name • "first definition wins" principle. • Android 4.4.3+ gives precedence to system applications • Android 5.0+ blocks installation completely for applications attempting to define an existing permission if they are signed with a different key than the first definer
- 9. 9 Request Permission Declare in AndroidMainifest.xml <manifest package="com.XXX"> <uses-permission android:name="android.permission.XXX" /> … </manifest>
- 10. 10 Grant Permission Grant the permission when installation before M.
- 11. 11 Grant Permission • Android cannot grant permissions that don’t exist yet If an application requires a permission which is not existing in system, the system will not grant the permission to the requesting application. • An application who defines <permission> is uninstalled, the permission records are removed from the system’s known permissions list. Any applications currently holding that permission will still have the permission granted to them until they are updated/reinstalled.
- 12. 12 Grant Permission (2) Assign permission in prebuilt etc/permission/platform.xml <assign-permission name="android.permission.MODIFY_AUDIO_SETTINGS" uid="media" /> Assign higher-level permissions to system processes running under a specific UID that do not have a corresponding package. Allows specific core system users to perform the given operations with the higher-level framework
- 13. 13 Enforce Permission • Kernel • Java components • Native daemons
- 14. 14 Enforce Permission - Kernel Access to files/device nodes/and local sockets is regulated by Kernel. Permission <map> Supplementary GIDs <permission name="android.permission.ACCESS_FM_RADIO" > <group gid="media" /> </permission> JNI APK Device Node Security check APK has a special permission which is mapped to GroupB in platform.xml Group B UserID :arbitrary
- 15. 15 Java Components - Static Managed by ActivityManagerService Components who uses permission Components who declares permission Check by AMS
- 16. 16 Java Components - Dynamic Programmatically check if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.XX) != PackageManager.PERMISSION_GRANTED) { throw new SecurityException("Requires XXX permission"); }
- 18. 18 Runtime Permission • Support in M • Dangerous permissions can be granted/revoked in runtime. • Other permission will be granted in installation automatically. • Only has to grant permission once per app for each permission group. • No difference for permission enforce
- 19. 19 Runtime Permission - Revoke Before M: Not allowed From M: Revocable from Settings.
- 20. 20 Runtime Permission - Caller • Always Check for Permissions • Handle Lack of Permissions Gracefully if (checkSelfPermission(Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) { if (shouldShowRequestPermissionRationale( Manifest.permission.READ_CONTACTS)) { } requestPermissions(new String[]{Manifest.permission.READ_CONTACTS}, MY_PERMISSIONS_REQUEST_READ_CONTACTS); return; }
Editor's Notes
- #12: When the application given a pending intent triggers the actual intent, it does so with the same permissions and the identity as the application that created the pending intent