Load fewer classes when AndroidKeyStore provider is installed.

This avoids loading all AndroidKeyStore crypto SPI classes when the
AndroidKeyStore provider is instantiated and installed. This provider
is installed early on during the initialization of each app. Most apps
don't need these classes loaded.

Bug: 18088752
Change-Id: Ib43c9dd6a7d434b128916e0f9c8652ba61df0d47

2 files changed, 23 insertions, 17 deletions

diff --git a/keystore/java/android/security/AndroidKeyStoreProvider.java b/keystore/java/android/security/AndroidKeyStoreProvider.java
index a26530c..a59927d 100644
--- a/keystore/java/android/security/AndroidKeyStoreProvider.java
+++ b/keystore/java/android/security/AndroidKeyStoreProvider.java
@@ -29,50 +29,58 @@ import javax.crypto.Mac;
 public class AndroidKeyStoreProvider extends Provider {
     public static final String PROVIDER_NAME = "AndroidKeyStore";
 
+    // IMPLEMENTATION NOTE: Class names are hard-coded in this provider to avoid loading these
+    // classes when this provider is instantiated and installed early on during each app's
+    // initialization process.
+
+    private static final String PACKAGE_NAME = "android.security";
+    private static final String KEYSTORE_SECRET_KEY_CLASS_NAME =
+            PACKAGE_NAME + ".KeyStoreSecretKey";
+
     public AndroidKeyStoreProvider() {
         super(PROVIDER_NAME, 1.0, "Android KeyStore security provider");
 
         // java.security.KeyStore
-        put("KeyStore." + AndroidKeyStore.NAME, AndroidKeyStore.class.getName());
+        put("KeyStore.AndroidKeyStore", PACKAGE_NAME + ".AndroidKeyStore");
 
         // java.security.KeyPairGenerator
-        put("KeyPairGenerator.EC", AndroidKeyPairGenerator.EC.class.getName());
-        put("KeyPairGenerator.RSA", AndroidKeyPairGenerator.RSA.class.getName());
+        put("KeyPairGenerator.EC", PACKAGE_NAME + ".AndroidKeyPairGenerator$EC");
+        put("KeyPairGenerator.RSA", PACKAGE_NAME +  ".AndroidKeyPairGenerator$RSA");
 
         // javax.crypto.KeyGenerator
-        put("KeyGenerator.AES", KeyStoreKeyGeneratorSpi.AES.class.getName());
-        put("KeyGenerator.HmacSHA256", KeyStoreKeyGeneratorSpi.HmacSHA256.class.getName());
+        put("KeyGenerator.AES", PACKAGE_NAME + ".KeyStoreKeyGeneratorSpi$AES");
+        put("KeyGenerator.HmacSHA256", PACKAGE_NAME + ".KeyStoreKeyGeneratorSpi$HmacSHA256");
 
         // java.security.SecretKeyFactory
-        put("SecretKeyFactory.AES", KeyStoreSecretKeyFactorySpi.class.getName());
-        put("SecretKeyFactory.HmacSHA256", KeyStoreSecretKeyFactorySpi.class.getName());
+        put("SecretKeyFactory.AES", PACKAGE_NAME + ".KeyStoreSecretKeyFactorySpi");
+        put("SecretKeyFactory.HmacSHA256", PACKAGE_NAME + ".KeyStoreSecretKeyFactorySpi");
 
         // javax.crypto.Mac
-        putMacImpl("HmacSHA256", KeyStoreHmacSpi.HmacSHA256.class.getName());
+        putMacImpl("HmacSHA256", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA256");
 
         // javax.crypto.Cipher
         putSymmetricCipherImpl("AES/ECB/NoPadding",
-                KeyStoreCipherSpi.AES.ECB.NoPadding.class.getName());
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$ECB$NoPadding");
         putSymmetricCipherImpl("AES/ECB/PKCS7Padding",
-                KeyStoreCipherSpi.AES.ECB.PKCS7Padding.class.getName());
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$ECB$PKCS7Padding");
 
         putSymmetricCipherImpl("AES/CBC/NoPadding",
-                KeyStoreCipherSpi.AES.CBC.NoPadding.class.getName());
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CBC$NoPadding");
         putSymmetricCipherImpl("AES/CBC/PKCS7Padding",
-                KeyStoreCipherSpi.AES.CBC.PKCS7Padding.class.getName());
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CBC$PKCS7Padding");
 
         putSymmetricCipherImpl("AES/CTR/NoPadding",
-                KeyStoreCipherSpi.AES.CTR.NoPadding.class.getName());
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CTR$NoPadding");
     }
 
     private void putMacImpl(String algorithm, String implClass) {
         put("Mac." + algorithm, implClass);
-        put("Mac." + algorithm + " SupportedKeyClasses", KeyStoreSecretKey.class.getName());
+        put("Mac." + algorithm + " SupportedKeyClasses", KEYSTORE_SECRET_KEY_CLASS_NAME);
     }
 
     private void putSymmetricCipherImpl(String transformation, String implClass) {
         put("Cipher." + transformation, implClass);
-        put("Cipher." + transformation + " SupportedKeyClasses", KeyStoreSecretKey.class.getName());
+        put("Cipher." + transformation + " SupportedKeyClasses", KEYSTORE_SECRET_KEY_CLASS_NAME);
     }
 
     /**
diff --git a/preloaded-classes b/preloaded-classes
index c8d8c5d..151766f 100644
--- a/preloaded-classes
+++ b/preloaded-classes
@@ -1146,8 +1146,6 @@ android.provider.Settings$SettingNotFoundException
 android.provider.Settings$System
 android.provider.Telephony$Mms
 android.renderscript.RenderScript
-android.security.AndroidKeyPairGenerator
-android.security.AndroidKeyStore
 android.security.AndroidKeyStoreProvider
 android.speech.tts.TextToSpeechService
 android.speech.tts.TextToSpeechService$SpeechItemV1