Merge "AndroidKeyStore keys should not be handled by Bouncy Castle." into mnc-dev

2 files changed, 113 insertions, 31 deletions

diff --git a/keystore/java/android/security/AndroidKeyStoreBCWorkaroundProvider.java b/keystore/java/android/security/AndroidKeyStoreBCWorkaroundProvider.java
new file mode 100644
index 0000000..45329cf
--- /dev/null
+++ b/keystore/java/android/security/AndroidKeyStoreBCWorkaroundProvider.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.security;
+
+import java.security.Provider;
+
+/**
+ * {@link Provider} of JCA crypto operations operating on Android KeyStore keys.
+ *
+ * <p>This provider was separated out of {@link AndroidKeyStoreProvider} to work around the issue
+ * that Bouncy Castle provider incorrectly declares that it accepts arbitrary keys (incl. Android
+ * KeyStore ones). This causes JCA to select the Bouncy Castle's implementation of JCA crypto
+ * operations for Android KeyStore keys unless Android KeyStore's own implementations are installed
+ * as higher-priority than Bouncy Castle ones. The purpose of this provider is to do just that: to
+ * offer crypto operations operating on Android KeyStore keys and to be installed at higher priority
+ * than the Bouncy Castle provider.
+ *
+ * <p>Once Bouncy Castle provider is fixed, this provider can be merged into the
+ * {@code AndroidKeyStoreProvider}.
+ *
+ * @hide
+ */
+class AndroidKeyStoreBCWorkaroundProvider extends Provider {
+
+    // 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";
+
+    AndroidKeyStoreBCWorkaroundProvider() {
+        super("AndroidKeyStoreBCWorkaround",
+                1.0,
+                "Android KeyStore security provider to work around Bouncy Castle");
+
+        // javax.crypto.Mac
+        putMacImpl("HmacSHA1", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA1");
+        putMacImpl("HmacSHA224", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA224");
+        putMacImpl("HmacSHA256", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA256");
+        putMacImpl("HmacSHA384", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA384");
+        putMacImpl("HmacSHA512", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA512");
+
+        // javax.crypto.Cipher
+        putSymmetricCipherImpl("AES/ECB/NoPadding",
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$ECB$NoPadding");
+        putSymmetricCipherImpl("AES/ECB/PKCS7Padding",
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$ECB$PKCS7Padding");
+
+        putSymmetricCipherImpl("AES/CBC/NoPadding",
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CBC$NoPadding");
+        putSymmetricCipherImpl("AES/CBC/PKCS7Padding",
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CBC$PKCS7Padding");
+
+        putSymmetricCipherImpl("AES/CTR/NoPadding",
+                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CTR$NoPadding");
+    }
+
+    private void putMacImpl(String algorithm, String implClass) {
+        put("Mac." + algorithm, implClass);
+        put("Mac." + algorithm + " SupportedKeyClasses", KEYSTORE_SECRET_KEY_CLASS_NAME);
+    }
+
+    private void putSymmetricCipherImpl(String transformation, String implClass) {
+        put("Cipher." + transformation, implClass);
+        put("Cipher." + transformation + " SupportedKeyClasses", KEYSTORE_SECRET_KEY_CLASS_NAME);
+    }
+}
diff --git a/keystore/java/android/security/AndroidKeyStoreProvider.java b/keystore/java/android/security/AndroidKeyStoreProvider.java
index 43f3b30..518067b 100644
--- a/keystore/java/android/security/AndroidKeyStoreProvider.java
+++ b/keystore/java/android/security/AndroidKeyStoreProvider.java
@@ -17,6 +17,7 @@
 package android.security;
 
 import java.security.Provider;
+import java.security.Security;
 
 import javax.crypto.Cipher;
 import javax.crypto.Mac;
@@ -32,10 +33,12 @@ public class AndroidKeyStoreProvider extends Provider {
     // 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.
+    //
+    // Crypto operations operating on the AndroidKeyStore keys must not be offered by this provider.
+    // Instead, they need to be offered by AndroidKeyStoreBCWorkaroundProvider. See its Javadoc
+    // for details.
 
     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");
@@ -62,43 +65,39 @@ public class AndroidKeyStoreProvider extends Provider {
         putSecretKeyFactoryImpl("HmacSHA256");
         putSecretKeyFactoryImpl("HmacSHA384");
         putSecretKeyFactoryImpl("HmacSHA512");
+    }
 
-        // javax.crypto.Mac
-        putMacImpl("HmacSHA1", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA1");
-        putMacImpl("HmacSHA224", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA224");
-        putMacImpl("HmacSHA256", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA256");
-        putMacImpl("HmacSHA384", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA384");
-        putMacImpl("HmacSHA512", PACKAGE_NAME + ".KeyStoreHmacSpi$HmacSHA512");
-
-        // javax.crypto.Cipher
-        putSymmetricCipherImpl("AES/ECB/NoPadding",
-                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$ECB$NoPadding");
-        putSymmetricCipherImpl("AES/ECB/PKCS7Padding",
-                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$ECB$PKCS7Padding");
-
-        putSymmetricCipherImpl("AES/CBC/NoPadding",
-                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CBC$NoPadding");
-        putSymmetricCipherImpl("AES/CBC/PKCS7Padding",
-                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CBC$PKCS7Padding");
+    /**
+     * Installs a new instance of this provider (and the
+     * {@link AndroidKeyStoreBCWorkaroundProvider}).
+     */
+    public static void install() {
+        Provider[] providers = Security.getProviders();
+        int bcProviderPosition = -1;
+        for (int position = 0; position < providers.length; position++) {
+            Provider provider = providers[position];
+            if ("BC".equals(provider.getName())) {
+                bcProviderPosition = position;
+                break;
+            }
+        }
 
-        putSymmetricCipherImpl("AES/CTR/NoPadding",
-                PACKAGE_NAME + ".KeyStoreCipherSpi$AES$CTR$NoPadding");
+        Security.addProvider(new AndroidKeyStoreProvider());
+        Provider workaroundProvider = new AndroidKeyStoreBCWorkaroundProvider();
+        if (bcProviderPosition != -1) {
+            // Bouncy Castle provider found -- install the workaround provider above it.
+            Security.insertProviderAt(workaroundProvider, bcProviderPosition);
+        } else {
+            // Bouncy Castle provider not found -- install the workaround provider at lowest
+            // priority.
+            Security.addProvider(workaroundProvider);
+        }
     }
 
     private void putSecretKeyFactoryImpl(String algorithm) {
         put("SecretKeyFactory." + algorithm, PACKAGE_NAME + ".KeyStoreSecretKeyFactorySpi");
     }
 
-    private void putMacImpl(String algorithm, String implClass) {
-        put("Mac." + algorithm, implClass);
-        put("Mac." + algorithm + " SupportedKeyClasses", KEYSTORE_SECRET_KEY_CLASS_NAME);
-    }
-
-    private void putSymmetricCipherImpl(String transformation, String implClass) {
-        put("Cipher." + transformation, implClass);
-        put("Cipher." + transformation + " SupportedKeyClasses", KEYSTORE_SECRET_KEY_CLASS_NAME);
-    }
-
     /**
      * Gets the {@link KeyStore} operation handle corresponding to the provided JCA crypto
      * primitive.