From 3e7cf168a547982676f18d3308b83381abc95f06 Mon Sep 17 00:00:00 2001
From: Robin Lee <rgl@google.com>
Date: Sat, 25 Feb 2017 01:28:25 +0000
Subject: [PATCH] Make IKeyChainAliasCallback oneway

So it can be sent from devicepolicymanager (system_server) to keychain
(a system_app) without waiting on the response and having to do
everything in a background thread.

Side-effect: the regular keychain => app callback is slightly more
efficient now too. in case anyone particularly needs blazing fast
private key user selections.

Fix: 35675253
Test: cts-tradefed run cts --abi=arm64-v8a --skip-device-info --module CtsDevicePolicyManagerTestCases --test 'com.android.cts.devicepolicy.DeviceOwnerTest#testKeyManagement' </dev/null 2>&1
Change-Id: I6e9d96ca3c42e6489d879d8cfb0507eb94838bf1
---
 .../security/IKeyChainAliasCallback.aidl      |  2 +-
 .../DevicePolicyManagerService.java           | 22 ++++++++-----------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/keystore/java/android/security/IKeyChainAliasCallback.aidl b/keystore/java/android/security/IKeyChainAliasCallback.aidl
index 1ea952166009e..b9d37533de80d 100644
--- a/keystore/java/android/security/IKeyChainAliasCallback.aidl
+++ b/keystore/java/android/security/IKeyChainAliasCallback.aidl
@@ -20,7 +20,7 @@ package android.security;
  *
  * @hide
  */
-interface IKeyChainAliasCallback {
+oneway interface IKeyChainAliasCallback {
 
     void alias(String alias);
 }
diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
index 14b1741346b9b..5cd1427e07018 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
@@ -4828,19 +4828,15 @@ public class DevicePolicyManagerService extends IDevicePolicyManager.Stub {
     private void sendPrivateKeyAliasResponse(final String alias, final IBinder responseBinder) {
         final IKeyChainAliasCallback keyChainAliasResponse =
                 IKeyChainAliasCallback.Stub.asInterface(responseBinder);
-        new AsyncTask<Void, Void, Void>() {
-            @Override
-            protected Void doInBackground(Void... unused) {
-                try {
-                    keyChainAliasResponse.alias(alias);
-                } catch (Exception e) {
-                    // Catch everything (not just RemoteException): caller could throw a
-                    // RuntimeException back across processes.
-                    Log.e(LOG_TAG, "error while responding to callback", e);
-                }
-                return null;
-            }
-        }.execute();
+        // Send the response. It's OK to do this from the main thread because IKeyChainAliasCallback
+        // is oneway, which means it won't block if the recipient lives in another process.
+        try {
+            keyChainAliasResponse.alias(alias);
+        } catch (Exception e) {
+            // Caller could throw RuntimeException or RemoteException back across processes. Catch
+            // everything just to be sure.
+            Log.e(LOG_TAG, "error while responding to callback", e);
+        }
     }
 
     /**