From 2c4d44c5b9b351bb3db0cf0f4122fc771f270541 Mon Sep 17 00:00:00 2001
From: Torsten Grote <t@grobox.de>
Date: Thu, 19 Sep 2019 15:21:48 -0300
Subject: [PATCH] Grant MANAGE_USB permission, so we can get USB serial numbers

This is needed to reliably identify USB mass storage devices.
If someone has several identical thumb drives,
this prevents a backup from being performed when non-backup drives get attached.
---
 app/src/main/AndroidManifest.xml                             | 5 +++++
 .../main/java/com/stevesoltys/backup/UsbIntentReceiver.kt    | 2 +-
 .../java/com/stevesoltys/backup/settings/SettingsManager.kt  | 2 +-
 permissions_com.stevesoltys.backup.xml                       | 1 +
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 5bb46f4e..fdded5ea 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -14,6 +14,11 @@
         android:name="android.permission.MANAGE_DOCUMENTS"
         tools:ignore="ProtectedPermissions" />
 
+    <!-- This is needed to access the serial number of USB mass storage devices -->
+    <uses-permission
+        android:name="android.permission.MANAGE_USB"
+        tools:ignore="ProtectedPermissions" />
+
     <application
         android:name=".Backup"
         android:allowBackup="false"
diff --git a/app/src/main/java/com/stevesoltys/backup/UsbIntentReceiver.kt b/app/src/main/java/com/stevesoltys/backup/UsbIntentReceiver.kt
index 395ade25..a9b94ebc 100644
--- a/app/src/main/java/com/stevesoltys/backup/UsbIntentReceiver.kt
+++ b/app/src/main/java/com/stevesoltys/backup/UsbIntentReceiver.kt
@@ -77,7 +77,7 @@ private fun UsbInterface.isMassStorage(): Boolean {
 
 private fun UsbDevice.log() {
     Log.d(TAG, "  name: $manufacturerName $productName")
-//    Log.d(TAG, "  serialNumber: $serialNumber")  // requires a permission since API 29
+    Log.d(TAG, "  serialNumber: $serialNumber")
     Log.d(TAG, "  productId: $productId")
     Log.d(TAG, "  vendorId: $vendorId")
     Log.d(TAG, "  isMassStorage: ${isMassStorage()}")
diff --git a/app/src/main/java/com/stevesoltys/backup/settings/SettingsManager.kt b/app/src/main/java/com/stevesoltys/backup/settings/SettingsManager.kt
index d71fc463..fd170df1 100644
--- a/app/src/main/java/com/stevesoltys/backup/settings/SettingsManager.kt
+++ b/app/src/main/java/com/stevesoltys/backup/settings/SettingsManager.kt
@@ -131,7 +131,7 @@ data class FlashDrive(
     companion object {
         fun from(device: UsbDevice) = FlashDrive(
                 name = "${device.manufacturerName} ${device.productName}",
-                serialNumber = "", // device.serialNumber requires a permission since API 29
+                serialNumber = device.serialNumber,
                 vendorId = device.vendorId,
                 productId = device.productId
         )
diff --git a/permissions_com.stevesoltys.backup.xml b/permissions_com.stevesoltys.backup.xml
index a5ee7318..34ed8dc9 100644
--- a/permissions_com.stevesoltys.backup.xml
+++ b/permissions_com.stevesoltys.backup.xml
@@ -2,5 +2,6 @@
 <permissions>
     <privapp-permissions package="com.stevesoltys.backup">
         <permission name="android.permission.BACKUP"/>
+        <permission name="android.permission.MANAGE_USB"/>
     </privapp-permissions>
 </permissions>
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