Exclude webcam and MIDI USB preferences from requiring auth challenge

Webcam / MIDI don't transfer any persistent data to the host device,
so it is okay to not guard it by an auth challenge. Auth challenge for
webcam use increases friction and reduces usability.

Bug: 349370229

Flag: com.android.settings.flags.exclude_webcam_auth_challenge

Test: Check when the flag is enabled, webcam / MIDI doesn't require auth
Test: Settings robolectric tests

Change-Id: Id4c97a635a4c0a9ed14f88fbdda2743e2371dd10
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>

aconfig/settings_connecteddevice_flag_declarations.aconfig

@@ -38,3 +38,13 @@ flag {
         purpose: PURPOSE_BUGFIX
     }
 }
+
+flag {
+    name: "exclude_webcam_auth_challenge"
+    namespace: "safety_center"
+    description: "Gates whether to exclude webcam from USB preferences auth challenge."
+    bug: "349370229"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}

src/com/android/settings/connecteddevice/usb/UsbDetailsFunctionsController.java

@@ -31,6 +31,7 @@ import androidx.preference.PreferenceScreen;
 
 import com.android.settings.R;
 import com.android.settings.Utils;
+import com.android.settings.flags.Flags;
 import com.android.settingslib.widget.SelectorWithWidgetPreference;
 
 import java.util.LinkedHashMap;
@@ -130,8 +131,15 @@ public class UsbDetailsFunctionsController extends UsbDetailsController
 
     @Override
     public void onRadioButtonClicked(SelectorWithWidgetPreference preference) {
-        requireAuthAndExecute(() -> {
         final long function = UsbBackend.usbFunctionsFromString(preference.getKey());
+        if (isAuthRequired(function)) {
+            requireAuthAndExecute(()->handleRadioButtonClicked(preference, function));
+        } else {
+            handleRadioButtonClicked(preference, function);
+        }
+    }
+
+    private void handleRadioButtonClicked(SelectorWithWidgetPreference preference, long function) {
         final long previousFunction = mUsbBackend.getCurrentFunctions();
         if (DEBUG) {
             Log.d(TAG, "onRadioButtonClicked() function : " + function + ", toString() : "
@@ -162,7 +170,15 @@ public class UsbDetailsFunctionsController extends UsbDetailsController
                 mUsbBackend.setCurrentFunctions(function);
             }
         }
-        });
+    }
+
+    private boolean isAuthRequired(long function) {
+        if (!Flags.excludeWebcamAuthChallenge()) {
+            return true;
+        }
+        // Since webcam and MIDI don't transfer any persistent data over USB
+        // don't require authentication.
+        return !(function == UsbManager.FUNCTION_UVC || function == UsbManager.FUNCTION_MIDI);
     }
 
     private boolean isClickEventIgnored(long function, long previousFunction) {

tests/robotests/src/com/android/settings/connecteddevice/usb/UsbDetailsFunctionsControllerTest.java

@@ -35,6 +35,8 @@ import android.content.Context;
 import android.hardware.usb.UsbManager;
 import android.net.TetheringManager;
 import android.platform.test.annotations.RequiresFlagsEnabled;
+import android.platform.test.flag.junit.CheckFlagsRule;
+import android.platform.test.flag.junit.DeviceFlagsValueProvider;
 
 import androidx.fragment.app.FragmentActivity;
 import androidx.preference.PreferenceCategory;
@@ -48,6 +50,7 @@ import com.android.settingslib.widget.SelectorWithWidgetPreference;
 
 import org.junit.Before;
 import org.junit.Ignore;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
@@ -82,6 +85,8 @@ public class UsbDetailsFunctionsControllerTest {
     private FragmentActivity mActivity;
     @Mock
     private TetheringManager mTetheringManager;
+    @Rule
+    public final CheckFlagsRule mCheckFlagsRule = DeviceFlagsValueProvider.createCheckFlagsRule();
 
     @Before
     public void setUp() {
@@ -349,6 +354,30 @@ public class UsbDetailsFunctionsControllerTest {
         assertThat(mFragment.isUserAuthenticated()).isTrue();
     }
 
+    @Test
+    @RequiresFlagsEnabled(Flags.FLAG_EXCLUDE_WEBCAM_AUTH_CHALLENGE)
+    public void onRadioButtonClicked_webcamNoAuthNeeded() {
+        mRadioButtonPreference.setKey(UsbBackend.usbFunctionsToString(UsbManager.FUNCTION_UVC));
+        doReturn(UsbManager.FUNCTION_MTP).when(mUsbBackend).getCurrentFunctions();
+        setAuthPassesAutomatically();
+
+        mDetailsFunctionsController.onRadioButtonClicked(mRadioButtonPreference);
+
+        assertThat(mFragment.isUserAuthenticated()).isFalse();
+    }
+
+    @Test
+    @RequiresFlagsEnabled(Flags.FLAG_EXCLUDE_WEBCAM_AUTH_CHALLENGE)
+    public void onRadioButtonClicked_MidiNoAuthNeeded() {
+        mRadioButtonPreference.setKey(UsbBackend.usbFunctionsToString(UsbManager.FUNCTION_MIDI));
+        doReturn(UsbManager.FUNCTION_MTP).when(mUsbBackend).getCurrentFunctions();
+        setAuthPassesAutomatically();
+
+        mDetailsFunctionsController.onRadioButtonClicked(mRadioButtonPreference);
+
+        assertThat(mFragment.isUserAuthenticated()).isFalse();
+    }
+
     private void setAuthPassesAutomatically() {
         Shadows.shadowOf(mContext.getSystemService(KeyguardManager.class))
                 .setIsKeyguardSecure(false);