linux

lib/crypto: polyval: Add POLYVAL library Add support for POLYVAL to lib/crypto/. This will replace the polyval crypto_shash algorithm and its use in the hctr2 template, simplifying the code and reducing overhead. Specifically, this commit introduces the POLYVAL library API and a generic implementation of it. Later commits will migrate the existing architecture-optimized implementations of POLYVAL into lib/crypto/ and add a KUnit test suite. I've also rewritten the generic implementation completely, using a more modern approach instead of the traditional table-based approach. It's now constant-time, requires no precomputation or dynamic memory allocations, decreases the per-key memory usage from 4096 bytes to 16 bytes, and is faster than the old polyval-generic even on bulk data reusing the same key (at least on x86_64, where I measured 15% faster). We should do this for GHASH too, but for now just do it for POLYVAL. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20251109234726.638437-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> 2025-11-09 15:47:17 -08:00