Fido: Re-request permission when result isn't received

It may happen that the OS doesn't ask for the permission:
We re-request the permission every seconds until it is correctly received, with a maximum
of 5 attempts, or when the user navigate back to the USB selection

Author: p1gp1g

play-services-fido/core/src/main/kotlin/org/microg/gms/fido/core/transport/usb/UsbDevicePermissionManager.kt

@@ -9,12 +9,16 @@ import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
+import android.util.Log
 import android.hardware.usb.UsbDevice
 import android.hardware.usb.UsbManager
+import android.os.Build
 import androidx.core.app.PendingIntentCompat
 import androidx.core.content.ContextCompat
 import androidx.core.content.ContextCompat.RECEIVER_NOT_EXPORTED
 import kotlinx.coroutines.CompletableDeferred
+import java.util.Timer
+import java.util.TimerTask
 
 private val Context.usbPermissionCallbackAction
     get() = "$packageName.USB_PERMISSION_CALLBACK"
@@ -40,6 +44,10 @@ private object UsbDevicePermissionReceiver : BroadcastReceiver() {
         }
     }
 
+    fun isDeferred(device: UsbDevice): Boolean = synchronized(this) {
+        return pendingRequests.containsKey(device)
+    }
+
     fun unregister(context: Context) = synchronized(this) {
         if (registered) {
             context.unregisterReceiver(this)
@@ -75,10 +83,39 @@ class UsbDevicePermissionManager(private val context: Context) {
         if (context.usbManager?.hasPermission(device) == true) return true
         val res = CompletableDeferred<Boolean>()
         if (UsbDevicePermissionReceiver.addDeferred(device, res)) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                Log.d(TAG, "PermissionReceiver added for ${device.productName} (${context.packageName})")
+            }
             UsbDevicePermissionReceiver.register(context)
-            val intent = PendingIntentCompat.getBroadcast(context, 0, Intent(context.usbPermissionCallbackAction).apply { `package` = context.packageName }, 0, true)
-            context.usbManager?.requestPermission(device, intent)
+            schedulePermissionRequest(device, 5)
+        } else {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                Log.d(TAG, "PermissionReceiver already added for ${device.productName}")
+            }
         }
+        requestPermission(device)
         return res.await()
     }
+
+    // In case we couldn't ask for permission, retry every secondes, with a maximum of `maxRetries`
+    private fun schedulePermissionRequest(device: UsbDevice, maxRetries: Int) {
+        if (maxRetries < 1) return
+        Timer().schedule(object : TimerTask() {
+            override fun run() {
+                if (UsbDevicePermissionReceiver.isDeferred(device)) {
+                    requestPermission(device)
+                    schedulePermissionRequest(device, maxRetries - 1)
+                }
+            }
+        }, 1000)
+    }
+
+    private fun requestPermission(device: UsbDevice) {
+        val intent = PendingIntentCompat.getBroadcast(context, 0, Intent(context.usbPermissionCallbackAction).apply { `package` = context.packageName }, 0, true)
+        context.usbManager?.requestPermission(device, intent)
+    }
+
+    companion object {
+        private const val TAG = "UsbDevicePermissionMan"
+    }
 }