[Android N] Content provider cannot be used in SQLCipher 3.5.1?



Thank you for your work to integrate SQLCipher to Android N OS.
Through your notification and the source code, the content provider scheme in Android seems to be not supported from SQLCipher 3.5.1.
Is this right ?
If so, I’d like to know that if you have any plan for supporting the content provider.



Can you point to the specific change(s) that break the content provider compatibility?

Also can you give any pointers how to test the content provider compatibility in the future?


Content provider is a way of accessing common database from several processes.
As I know, CursorWindow must be created in ashmem to share the query result between the provider and the clients, and
binder protocol is also necessary.

The notification says that libbinder is removed.
-> 1.All internal and third-party library dependencies except for OpenSSL (the crypto provider) have been removed. Thisincludes libbinder, libandroid_runtime, libnativehelper, libcutils, libutils, and libicuc.
Besides there are no codes for ashmem in CursorWindow.cpp.
I think that inter-process share of database is not possible in SQLCipher.


In case you haven’t seen it there is an excellent tutorial of how to create an Android SQLite Content Provider at: http://www.vogella.com/tutorials/AndroidSQLite/article.html

According to [2] you would have to implement functions such as query(), insert(), update(), delete(), etc. to create a custom content provider.

In [3] there is a sample content provider where the results of query() are simply returned as a subclass of android.database.Cursor. I think you know certain SQLCipher database functions such as multiple versions of net.sqlcipher.database.SQLiteDatabase.rawQuery() would return the SELECT query results as a subclass of android.database.Cursor.

In case a content provider returns a Cursor object that does not use shared memory, I suspect the Android system would handle the data sharing. Or do you think I am mistaken here?

In case you think this is an issue you may want to raise it on GitHub.

[1] http://www.vogella.com/tutorials/AndroidSQLite/article.html
[2] http://www.vogella.com/tutorials/AndroidSQLite/article.html#custom-content-provider
[3] http://www.vogella.com/tutorials/AndroidSQLite/article.html#custom-content-provider


Hi @Kyle, @brodybits,

@Kyle is correct in that we removed the ashmem component of the old library as mentioned in our prerelease and release annoucements for our Android N support; this was at the request of the Google Android team and is a requirement for running on Android N. We do not have plans to support that going forward.


Thanks @developernotes. I think the original question whether or not SQLCipher 3.5.1 can be used to support an Android Content Provider is still not answered 10)%. I think it should be possible to use SQLCIpher for a content provider but would have to test it to confirm. I have no idea when I would get a chance to test this.