On newer devices, use dm-default-key to encrypt SD cards
The dm-crypt solution requires a kernel patch that won't be present in
the GKI kernel, while the new metadata encryption system in the GKI
kernel solves this problem in a much cleaner way.
Test: create private volume on Cuttlefish, setting property both ways.
Bug: 147814592
Change-Id: Ie02bd647c38d8101af2bbc47637f65845d312cea
diff --git a/model/VolumeEncryption.h b/model/VolumeEncryption.h
new file mode 100644
index 0000000..d06c12b
--- /dev/null
+++ b/model/VolumeEncryption.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#pragma once
+
+#include <string>
+
+#include "KeyBuffer.h"
+
+namespace android {
+namespace vold {
+
+bool generate_volume_key(android::vold::KeyBuffer* key);
+
+bool setup_ext_volume(const std::string& label, const std::string& blk_device,
+ const android::vold::KeyBuffer& key, std::string* out_crypto_blkdev);
+
+} // namespace vold
+} // namespace android