Mounting encrypted OBB files has never worked reliably across devices,
partly due to its reliance on Twofish encryption support in the kernel.
This is because Twofish support (CONFIG_CRYPTO_TWOFISH) has never been
required or even recommended for Android. It has never been enabled in
GKI, but even before GKI it wasn't required or recommended. Moreover,
this is now the only Android feature that still uses dm-crypt
(CONFIG_DM_CRYPT), and some devices don't have that enabled either.
Therefore, it appears that this feature is unused. That's perhaps not
surprising, considering that the documentation for OBBs
(https://developer.android.com/google/play/expansion-files) says that
they are deprecated, and also it explains OBBs as being app files that
are opaque to the platform; the ability of the platform to mount OBBs
that happen to be in a particular format is never mentioned. That means
that OBB mounting is probably rarely used even with unencrypted OBBs.
Finally, the usefulness of OBBs having their own encryption layer (in
addition to what the platform already provides via FBE) is not clear
either, especially with such an unusual choice of cipher.
To avoid the confusion that is being caused by having the broken code
for mounting encrypted OBBs still sitting around, let's remove it.
Test: atest StorageManagerTest # on Cuttlefish
Test: atest StorageManagerIntegrationTest # on Cuttlefish
Bug: 216475849
Change-Id: I6e6a6462ab8343299dc5e0145b87dc28b16b0bc1
StorageManagerService uses DefaultContainerService to obtain ObbInfo
for files passed through mountObb() transaction. This change moves this
logic to client side and so ObbInfo will be passed as part of mountObb()
transaction.
Bug: 111838160
Test: atest src/android/os/storage/cts/StorageManagerTest.java
Test: atest core/tests/coretests/src/android/os/storage/StorageManagerIntegrationTest.java
Test: atest services/tests/servicestests/src/com/android/server/MountServiceTests.java
Change-Id: I29aee3aa54a45057df96aae289888161a3e3af71
Since emulated external storage paths differ based on execution
context, carefully fix up paths for various use-cases:
1. When sending paths to DefaultContainerService, always scope
OBB paths as belonging to USER_OWNER.
2. When sending paths to vold, always build emulated storage paths
visible to root.
3. Always use the original untouched path when talking with apps.
Mount OBB containers using shared app GID, so that an app can read
the mount point across users.
Handle legacy paths like "/sdcard" by resolving the canonical path
before sending to MountService. Move tests to servicestests, and
add tests for new path generation logic.
Bug: 7212801
Change-Id: I078c52879cd08d9c8a52cc8c83ac7ced1e8035e7
Rearrange structure of MountService handling of OBBs to be entirely
asynchronous so we don't rely on locking as much. We still need the
locking to support dumpsys which has been improved to output all the
data structures for OBBs.
Added more tests to cover more of the error return codes.
Oh and fix a logic inversion bug.
Change-Id: I34f541192dbbb1903b24825889b8fa8f43e6e2a9
Add a callback for users of the StorageManager API to be able to receive
notifications when the requested operation completes for mountObb and
unmountObb.
Add NDK API to get to ObbInfo like the Java API has.
Also update the docs for the API and remove the "STOPSHIP" comments.
Change-Id: I23a4409c7f8b74d3169614beba920b4d667990a4
