Adiantum & Streebog Sent In For Linux 4.21 Along With Various Crypto Performance Boosts

The crypto subsystem changes for the Linux 4.21 kernel were sent in this morning and they are quite exciting.

Most notably, Adiantum was added as Google's replacement for their original Speck plans for supporting data encryption on low-end Android Go devices that lack native crypto extensions on the CPU/SoC. Adiantum's performance beats out Speck and most importantly there aren't the concerns like there were with Speck with it being developed by the NSA and potentially back-doored.

The Adiantum changes are part of this pull request, which builds atop XChaCha12/XChaCha20. With this Adiantum work also comes various performance improvements around ChaCha20 on ARM64 and x86 (x86_64), NEON / SSE2 / AVX2 acceleration for HPoly, and other crypto performance work.

Staged separately is the Adiantum support for fscrypt so the likes of EXT4 and F2FS can then offer up this encryption support. Those fscrypt changes are expected to be pulled in too for Linux 4.21.

Also part of this pull request is the Streebog hashing function is added. Streebog was developed by the Russian FSB security services and other organizations. At the moment there doesn't appear to be any in-kernel users of Streebog lined up.

More details on all of the crypto improvements for Linux 4.21 via this pull request.