Fix boot regression from KeyStore being slow

Getting the secret hashfunction from KeyStore had increased wifi service
start time by ~20ms.

Moving this to loadFromStore, which happens right after boot complete, should
fix the problem.

Bug: 144579147
Test: atest FrameworksWifiTests
Change-Id: I478f1d558121e56e3d8bdeed4220eb8ba4ef097a
Merged-In: I478f1d558121e56e3d8bdeed4220eb8ba4ef097a
(cherry picked from: 0c6db026e4463abb4030cdf4f7813152f2dd1996)

2 files changed, 17 insertions, 6 deletions

diff --git a/service/java/com/android/server/wifi/WifiConfigManager.java b/service/java/com/android/server/wifi/WifiConfigManager.java
index b5d06ff05..1f53527e2 100644
--- a/service/java/com/android/server/wifi/WifiConfigManager.java
+++ b/service/java/com/android/server/wifi/WifiConfigManager.java
@@ -278,7 +278,7 @@ public class WifiConfigManager {
     private final WifiInjector mWifiInjector;
     private final MacAddressUtil mMacAddressUtil;
     private boolean mConnectedMacRandomzationSupported;
-    private final Mac mMac;
+    private Mac mMac;
 
     /**
      * Local log used for debugging any WifiConfigManager issues.
@@ -454,11 +454,6 @@ public class WifiConfigManager {
             Log.e(TAG, "Unable to resolve SystemUI's UID.");
         }
         mMacAddressUtil = mWifiInjector.getMacAddressUtil();
-        mMac = mMacAddressUtil.obtainMacRandHashFunction(Process.WIFI_UID);
-        if (mMac == null) {
-            Log.wtf(TAG, "Failed to obtain secret for MAC randomization."
-                    + " All randomized MAC addresses are lost!");
-        }
     }
 
     /**
@@ -3202,6 +3197,12 @@ public class WifiConfigManager {
      * @return true on success or not needed (fresh install), false otherwise.
      */
     public boolean loadFromStore() {
+        // Get the hashfunction that is used to generate randomized MACs from the KeyStore
+        mMac = mMacAddressUtil.obtainMacRandHashFunction(Process.WIFI_UID);
+        if (mMac == null) {
+            Log.wtf(TAG, "Failed to obtain secret for MAC randomization."
+                    + " All randomized MAC addresses are lost!");
+        }
         // If the user unlock comes in before we load from store, which means the user store have
         // not been setup yet for the current user. Setup the user store before the read so that
         // configurations for the current user will also being loaded.
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java b/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java
index 95a1e84e0..a1b1a298c 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java
@@ -296,6 +296,16 @@ public class WifiConfigManagerTest {
     }
 
     /**
+     * Verifies that the Mac randomization secret hashfunction is obtained after |loadFromStore|.
+     */
+    @Test
+    public void testMacHashIsObtainedAfterLoadFromStore() {
+        verify(mMacAddressUtil, never()).obtainMacRandHashFunction(anyInt());
+        assertTrue(mWifiConfigManager.loadFromStore());
+        verify(mMacAddressUtil).obtainMacRandHashFunction(anyInt());
+    }
+
+    /**
      * Verifies the addition of a single network using
      * {@link WifiConfigManager#addOrUpdateNetwork(WifiConfiguration, int)}
      */