Keystore 2.0 SPI: Fix NPE in getUniqueAliases.

getUniqueAliases may return a null if an error occurred. This would lead
to a NPE in engineAliases.

This patch makes getUniqueAliases return an empty HashSet instead.

Test: atest KeystoreTests

Change-Id: I387d90ea851a8b9c18bb2b20d1a0bfc1ab76c99f

1 files changed, 14 insertions, 2 deletions

diff --git a/keystore/java/android/security/keystore2/AndroidKeyStoreSpi.java b/keystore/java/android/security/keystore2/AndroidKeyStoreSpi.java
index 3e2fb94f0387..f3cfcf18dec1 100644
--- a/keystore/java/android/security/keystore2/AndroidKeyStoreSpi.java
+++ b/keystore/java/android/security/keystore2/AndroidKeyStoreSpi.java
@@ -41,6 +41,8 @@ import android.system.keystore2.KeyMetadata;
 import android.system.keystore2.ResponseCode;
 import android.util.Log;
 
+import com.android.internal.annotations.VisibleForTesting;
+
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -974,7 +976,6 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
     }
 
     private Set<String> getUniqueAliases() {
-
         try {
             final KeyDescriptor[] keys = mKeyStore.list(
                     getTargetDomain(),
@@ -987,7 +988,7 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
             return aliases;
         } catch (android.security.KeyStoreException e) {
             Log.e(TAG, "Failed to list keystore entries.", e);
-            return null;
+            return new HashSet<>();
         }
     }
 
@@ -1099,6 +1100,17 @@ public class AndroidKeyStoreSpi extends KeyStoreSpi {
         return caAlias;
     }
 
+    /**
+     * Used by Tests to initialize with a fake KeyStore2.
+     * @hide
+     * @param keystore
+     */
+    @VisibleForTesting
+    public void initForTesting(KeyStore2 keystore) {
+        mKeyStore = keystore;
+        mNamespace = KeyProperties.NAMESPACE_APPLICATION;
+    }
+
     @Override
     public void engineStore(OutputStream stream, char[] password) throws IOException,
             NoSuchAlgorithmException, CertificateException {