Android Permissions - Protection Levels

Android Permissions - Protection Levels

Android applications declare the permissions they are likely to require in their manifest (a short file that describes the contents of the 'package'). This allows the system to sandbox them from critical resources and gives the user some indication of what havoc they might reap. That's the theory at least, but the first time I installed an application and read the permissions page I had no idea what they were on about! Clearly this system needs to be changed, but that is not what I want to talk about today.

As an application writer I need to know the protection level of these permissions, i.e. which of these permissions are normal(can cause the user no real harm), dangerous (might require a greater level of trust, such as the ability to read SMS messages), signature (only granted to applications that are signed by the people who built the OS), signatureOrSystem (like signature, but also allowed if they have been pre-installed in a system folder). I was surprised to find no easy reference for thisin the documentation, but I did find the relevant information in the source.

You can of course probe the android package itself for this information, which is useful if you don't have access to the particular version of Android you are running. Here is some code that does just that:

// Get the permissions for the core android package PackageInfo packageInfo = getPackageManager().getPackageInfo("android", PackageManager.GET_PERMISSIONS); if (packageInfo.permissions != null) {   // For each defined permission   for (PermissionInfo permission : packageInfo.permissions) {     // Dump permission info     String protectionLevel;     switch(permission.protectionLevel) {     case PermissionInfo.PROTECTION_NORMAL : protectionLevel = "normal"; break;     case PermissionInfo.PROTECTION_DANGEROUS : protectionLevel = "dangerous"; break;     case PermissionInfo.PROTECTION_SIGNATURE : protectionLevel = "signature"; break;     case PermissionInfo.PROTECTION_SIGNATURE_OR_SYSTEM : protectionLevel = "signatureOrSystem"; break;     default : protectionLevel = "<unknown>"; break;     }     Log.i("PermissionCheck", permission.name + " " + protectionLevel);   } }

...and here are the results in case you need to know them at a glance...

Permission	Protection Level
android.intent.category.MASTER_CLEAR.permission.C2D_MESSAGE	signature
android.permission.ACCESS_CACHE_FILESYSTEM	signatureOrSystem
android.permission.ACCESS_CHECKIN_PROPERTIES	signatureOrSystem
android.permission.ACCESS_COARSE_LOCATION	dangerous
android.permission.ACCESS_FINE_LOCATION	dangerous
android.permission.ACCESS_LOCATION_EXTRA_COMMANDS	normal
android.permission.ACCESS_MOCK_LOCATION	dangerous
android.permission.ACCESS_NETWORK_STATE	normal
android.permission.ACCESS_SURFACE_FLINGER	signature
android.permission.ACCESS_WIFI_STATE	normal
android.permission.ACCOUNT_MANAGER	signature
android.permission.ASEC_ACCESS	signature
android.permission.ASEC_CREATE	signature
android.permission.ASEC_DESTROY	signature
android.permission.ASEC_MOUNT_UNMOUNT	signature
android.permission.ASEC_RENAME	signature
android.permission.AUTHENTICATE_ACCOUNTS	dangerous
android.permission.BACKUP	signatureOrSystem
android.permission.BATTERY_STATS	normal
android.permission.BIND_APPWIDGET	signatureOrSystem
android.permission.BIND_DEVICE_ADMIN	signature
android.permission.BIND_INPUT_METHOD	signature
android.permission.BIND_WALLPAPER	signatureOrSystem
android.permission.BLUETOOTH	dangerous
android.permission.BLUETOOTH_ADMIN	dangerous
android.permission.BRICK	signature
android.permission.BROADCAST_PACKAGE_REMOVED	signature
android.permission.BROADCAST_SMS	signature
android.permission.BROADCAST_STICKY	normal
android.permission.BROADCAST_WAP_PUSH	signature
android.permission.CALL_PHONE	dangerous
android.permission.CALL_PRIVILEGED	signatureOrSystem
android.permission.CAMERA	dangerous
android.permission.CHANGE_BACKGROUND_DATA_SETTING	signature
android.permission.CHANGE_COMPONENT_ENABLED_STATE	signature
android.permission.CHANGE_CONFIGURATION	dangerous
android.permission.CHANGE_NETWORK_STATE	dangerous
android.permission.CHANGE_WIFI_MULTICAST_STATE	dangerous
android.permission.CHANGE_WIFI_STATE	dangerous
android.permission.CLEAR_APP_CACHE	dangerous
android.permission.CLEAR_APP_USER_DATA	signature
android.permission.CONTROL_LOCATION_UPDATES	signatureOrSystem
android.permission.COPY_PROTECTED_DATA	signature
android.permission.DELETE_CACHE_FILES	signatureOrSystem
android.permission.DELETE_PACKAGES	signatureOrSystem
android.permission.DEVICE_POWER	signature
android.permission.DIAGNOSTIC	signature
android.permission.DISABLE_KEYGUARD	normal
android.permission.DUMP	dangerous
android.permission.EXPAND_STATUS_BAR	normal
android.permission.FACTORY_TEST	signature
android.permission.FLASHLIGHT	normal
android.permission.FORCE_BACK	signature
android.permission.FORCE_STOP_PACKAGES	signature
android.permission.GET_ACCOUNTS	normal
android.permission.GET_PACKAGE_SIZE	normal
android.permission.GET_TASKS	dangerous
android.permission.GLOBAL_SEARCH	signatureOrSystem
android.permission.GLOBAL_SEARCH_CONTROL	signature
android.permission.HARDWARE_TEST	signature
android.permission.INJECT_EVENTS	signature
android.permission.INSTALL_LOCATION_PROVIDER	signatureOrSystem
android.permission.INSTALL_PACKAGES	signatureOrSystem
android.permission.INTERNAL_SYSTEM_WINDOW	signature
android.permission.INTERNET	dangerous
android.permission.KILL_BACKGROUND_PROCESSES	normal
android.permission.MANAGE_ACCOUNTS	dangerous
android.permission.MANAGE_APP_TOKENS	signature
android.permission.MASTER_CLEAR	signatureOrSystem
android.permission.MODIFY_AUDIO_SETTINGS	dangerous
android.permission.MODIFY_PHONE_STATE	dangerous
android.permission.MOUNT_FORMAT_FILESYSTEMS	dangerous
android.permission.MOUNT_UNMOUNT_FILESYSTEMS	dangerous
android.permission.MOVE_PACKAGE	signatureOrSystem
android.permission.PACKAGE_USAGE_STATS	signature
android.permission.PERFORM_CDMA_PROVISIONING	signatureOrSystem
android.permission.PERSISTENT_ACTIVITY	dangerous
android.permission.PROCESS_OUTGOING_CALLS	dangerous
android.permission.READ_CALENDAR	dangerous
android.permission.READ_CONTACTS	dangerous
android.permission.READ_FRAME_BUFFER	signature
android.permission.READ_INPUT_STATE	signature
android.permission.READ_LOGS	dangerous
android.permission.READ_OWNER_DATA	dangerous
android.permission.READ_PHONE_STATE	dangerous
android.permission.READ_SMS	dangerous
android.permission.READ_SYNC_SETTINGS	normal
android.permission.READ_SYNC_STATS	normal
android.permission.READ_USER_DICTIONARY	dangerous
android.permission.REBOOT	signatureOrSystem
android.permission.RECEIVE_BOOT_COMPLETED	normal
android.permission.RECEIVE_MMS	dangerous
android.permission.RECEIVE_SMS	dangerous
android.permission.RECEIVE_WAP_PUSH	dangerous
android.permission.RECORD_AUDIO	dangerous
android.permission.REORDER_TASKS	dangerous
android.permission.RESTART_PACKAGES	normal
android.permission.SEND_SMS	dangerous
android.permission.SET_ACTIVITY_WATCHER	signature
android.permission.SET_ALWAYS_FINISH	dangerous
android.permission.SET_ANIMATION_SCALE	dangerous
android.permission.SET_DEBUG_APP	dangerous
android.permission.SET_ORIENTATION	signature
android.permission.SET_PREFERRED_APPLICATIONS	signature
android.permission.SET_PROCESS_LIMIT	dangerous
android.permission.SET_TIME	signatureOrSystem
android.permission.SET_TIME_ZONE	dangerous
android.permission.SET_WALLPAPER	normal
android.permission.SET_WALLPAPER_COMPONENT	signatureOrSystem
android.permission.SET_WALLPAPER_HINTS	normal
android.permission.SHUTDOWN	signature
android.permission.SIGNAL_PERSISTENT_PROCESSES	dangerous
android.permission.STATUS_BAR	signatureOrSystem
android.permission.STOP_APP_SWITCHES	signature
android.permission.SUBSCRIBED_FEEDS_READ	normal
android.permission.SUBSCRIBED_FEEDS_WRITE	dangerous
android.permission.SYSTEM_ALERT_WINDOW	dangerous
android.permission.UPDATE_DEVICE_STATS	signature
android.permission.USE_CREDENTIALS	dangerous
android.permission.VIBRATE	normal
android.permission.WAKE_LOCK	dangerous
android.permission.WRITE_APN_SETTINGS	dangerous
android.permission.WRITE_CALENDAR	dangerous
android.permission.WRITE_CONTACTS	dangerous
android.permission.WRITE_EXTERNAL_STORAGE	dangerous
android.permission.WRITE_GSERVICES	signatureOrSystem
android.permission.WRITE_OWNER_DATA	dangerous
android.permission.WRITE_SECURE_SETTINGS	signatureOrSystem
android.permission.WRITE_SETTINGS	dangerous
android.permission.WRITE_SMS	dangerous
android.permission.WRITE_SYNC_SETTINGS	dangerous
android.permission.WRITE_USER_DICTIONARY	normal
com.android.browser.permission.READ_HISTORY_BOOKMARKS	dangerous
com.android.browser.permission.WRITE_HISTORY_BOOKMARKS	dangerous