iDifferent types of permissions in android

1. Normal Permissions

• Granted at Installation: Users grant these permissions during app installation.
• Relatively Low Risk: These permissions generally don’t pose a significant risk to the user’s privacy or the device’s operation.
• Examples:
• ACCESS_NETWORK_STATE (view network connections)
• INTERNET (access the internet)
• READ_EXTERNAL_STORAGE (read from external storage)

2. Dangerous Permissions

• User Authorization at Runtime: Users must explicitly grant these permissions when the app requests them at runtime (Android 6.0 and above).
• Potential Privacy/Security Impacts: Dangerous permissions could allow access to sensitive data or system functionalities.
• Examples:
• ACCESS_FINE_LOCATION (get precise location)
• READ_CONTACTS (read user's contacts)
• RECORD_AUDIO (record audio)
• CAMERA (access the camera)

3. Special Permissions

• Higher Restriction Level: These permissions have stricter requirements and may not be granted to all apps.
• Examples:
• SYSTEM_ALERT_WINDOW (Draw over other apps)
• BIND_NOTIFICATION_LISTENER_SERVICE (Access to notifications)

4. Signature Permissions

• Granted to Apps Signed with the Same Key: Apps signed with the same digital certificate can share signature-level permissions.
• Custom Permissions Defined by the Developer: You can create your own signature permissions to enforce access control between your apps.

5. SignatureOrSystem Permissions

• Similar to Signature Permissions: Apps signed with the same key grant the permission.
• Exception for System Apps: Additionally, apps signed with the platform key (system apps) are also granted the permission.

Important Things to Note

• Manifest Declaration: Apps must declare the permissions they need in their AndroidManifest.xml file.
• Runtime Requests: For dangerous permissions (Android 6.0 or higher), apps must request them from the user at runtime, even if declared in the manifest.
• Permission Groups: Some dangerous permissions are grouped together. Requesting one permission in a group may implicitly grant the others in that group.
• Checking Permissions: Use ContextCompat.checkSelfPermission() to check if your app has already been granted a specific permission.

Best Practices

• Request the Minimum: Only request the permissions essential for your app’s core functionality.
• Provide Transparency: Explain to users why your app requires specific permissions.
• Handle Permission Denial Gracefully: Your app should function (with perhaps limited features) even if a user denies certain permissions.

Resources

• Official Android Documentation: https://developer.android.com/guide/topics/permissions/overview