Support for private (adopted) volumes.
This adds support for private volumes which is just a filesystem
wrapped in a dm-crypt layer. For now we're using the exact same
configuration as internal encryption (aes-cbc-essiv:sha256), but we
don't store any key material on the removable media. Instead, we
store the key on internal storage, and use the GPT partition GUID
to identify which key should be used.
This means that private external storage is effectively as secure as
the internal storage of the device. That is, if the internal storage
is encrypted, then our external storage key is also encrypted.
When partitioning disks, we now support a "private" mode which has
a PrivateVolume partition, and a currently unused 16MB metadata
partition reserved for future use. It also supports a "mixed" mode
which creates both a PublicVolume and PrivateVolume on the same
disk. Mixed mode is currently experimental.
For now, just add ext4 support to PrivateVolume; we'll look at f2fs
in a future change. Add VolumeBase lifecycle for setting up crypto
mappings, and extract blkid logic into shared method. Sprinkle some
more "static" around the cryptfs code to improve invariants.
Bug: 19993667
Change-Id: Ibd1df6250735b706959a1eb9d9f7219ea85912a0
diff --git a/VolumeBase.h b/VolumeBase.h
index e7be8fb..e3d91ff 100644
--- a/VolumeBase.h
+++ b/VolumeBase.h
@@ -87,7 +87,6 @@
status_t create();
status_t destroy();
-
status_t mount();
status_t unmount();
status_t format();
@@ -95,6 +94,8 @@
protected:
explicit VolumeBase(Type type);
+ virtual status_t doCreate();
+ virtual status_t doDestroy();
virtual status_t doMount() = 0;
virtual status_t doUnmount() = 0;
virtual status_t doFormat();