Ensure adb key store is instantiated before revoking grants

If adb is not enabled on a device then the adb key store is not
instantiated when the AdbDebuggingManager's handler is started as
in most cases it will not be needed. However if the user attempts
to revoke any previous adb grants when a device is booted with adb
disabled it will result in a NPE. This commit ensures the key store
is instantiated before attempting to revoke authorizations.

Test: atest AdbDebuggingManagerTest
Test: Manually invoked 'Revoke USB debugging authorizations' after
      a boot with adb disabled.
Fixes: 145790817

Change-Id: Id00e531c18412be009a211eec80a72867659608f
Merged-In: Id00e531c18412be009a211eec80a72867659608f
diff --git a/services/core/java/com/android/server/adb/AdbDebuggingManager.java b/services/core/java/com/android/server/adb/AdbDebuggingManager.java
index 4b48ef9..143474b 100644
--- a/services/core/java/com/android/server/adb/AdbDebuggingManager.java
+++ b/services/core/java/com/android/server/adb/AdbDebuggingManager.java
@@ -413,6 +413,11 @@
                 case MESSAGE_ADB_CLEAR: {
                     Slog.d(TAG, "Received a request to clear the adb authorizations");
                     mConnectedKeys.clear();
+                    // If the key store has not yet been instantiated then do so now; this avoids
+                    // the unnecessary creation of the key store when adb is not enabled.
+                    if (mAdbKeyStore == null) {
+                        mAdbKeyStore = new AdbKeyStore();
+                    }
                     mAdbKeyStore.deleteKeyStore();
                     cancelJobToUpdateAdbKeyStore();
                     break;
diff --git a/services/tests/servicestests/src/com/android/server/adb/AdbDebuggingManagerTest.java b/services/tests/servicestests/src/com/android/server/adb/AdbDebuggingManagerTest.java
index d4182f3d..5a1ad86 100644
--- a/services/tests/servicestests/src/com/android/server/adb/AdbDebuggingManagerTest.java
+++ b/services/tests/servicestests/src/com/android/server/adb/AdbDebuggingManagerTest.java
@@ -672,6 +672,30 @@
                 connectionTime2, mKeyStore.getLastConnectionTime(TEST_KEY_2));
     }
 
+    @Test
+    public void testClearAuthorizationsBeforeAdbEnabled() throws Exception {
+        // The adb key store is not instantiated until adb is enabled; however if the user attempts
+        // to clear the adb authorizations when adb is disabled after a boot a NullPointerException
+        // was thrown as deleteKeyStore is invoked against the key store. This test ensures the
+        // key store can be successfully cleared when adb is disabled.
+        mHandler = mManager.new AdbDebuggingHandler(FgThread.get().getLooper());
+
+        clearKeyStore();
+    }
+
+    @Test
+    public void testClearAuthorizationsDeletesKeyFiles() throws Exception {
+        mAdbKeyFile.createNewFile();
+        mAdbKeyXmlFile.createNewFile();
+
+        clearKeyStore();
+
+        assertFalse("The adb key file should have been deleted after revocation of the grants",
+                mAdbKeyFile.exists());
+        assertFalse("The adb xml key file should have been deleted after revocation of the grants",
+                mAdbKeyXmlFile.exists());
+    }
+
     /**
      * Runs an adb test with the provided configuration.
      *