Go "adiantum" SQLite VFS
This package wraps an SQLite VFS to offer encryption at rest.
Warning
This work was not certified by a cryptographer. If you need vetted encryption, you should purchase the SQLite Encryption Extension, and either wrap it, or seek assistance wrapping it.
The "adiantum" VFS wraps the default SQLite VFS using the
Adiantum
tweakable and length-preserving encryption.
In general, any HBSH construction can be used to wrap any VFS.
The default Adiantum construction uses XChaCha12 for its stream cipher,
AES for its block cipher, and NH and Poly1305 for hashing.
Additionally, we use Argon2id
to derive 256-bit keys from plain text.
The VFS encrypts all files except super journals: they never contain database data, only filenames, and padding them to the block size is problematic. Temporary files are encrypted with random keys, as they may contain database data. To avoid the overhead of encrypting temporary files, keep them in memory:
PRAGMA temp_store = memory;
Important
Adiantum is typically used for disk encryption. The standard threat model for disk encryption considers an adversary that can read multiple snapshots of a disk. The only security property that disk encryption (and this package) provides is that all information such an adversary can obtain is whether the data in a sector has (or has not) changed over time.
Caution
This package does not claim protect databases against forgery. Any encryption scheme that allows constant-time block updates can't prevent individual blocks from being reverted to former versions of themselves, so block-level authentication is of limited value.