summaryrefslogtreecommitdiff
path: root/include/crypto/polyval.h
AgeCommit message (Collapse)Author
2025-11-11lib/crypto: x86/polyval: Migrate optimized code into libraryEric Biggers
Migrate the x86_64 implementation of POLYVAL into lib/crypto/, wiring it up to the POLYVAL library interface. This makes the POLYVAL library be properly optimized on x86_64. This drops the x86_64 optimizations of polyval in the crypto_shash API. That's fine, since polyval will be removed from crypto_shash entirely since it is unneeded there. But even if it comes back, the crypto_shash API could just be implemented on top of the library API, as usual. Adjust the names and prototypes of the assembly functions to align more closely with the rest of the library code. Also replace a movaps instruction with movups to remove the assumption that the key struct is 16-byte aligned. Users can still align the key if they want (and at least in this case, movups is just as fast as movaps), but it's inconvenient to require it. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20251109234726.638437-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-11-11lib/crypto: arm64/polyval: Migrate optimized code into libraryEric Biggers
Migrate the arm64 implementation of POLYVAL into lib/crypto/, wiring it up to the POLYVAL library interface. This makes the POLYVAL library be properly optimized on arm64. This drops the arm64 optimizations of polyval in the crypto_shash API. That's fine, since polyval will be removed from crypto_shash entirely since it is unneeded there. But even if it comes back, the crypto_shash API could just be implemented on top of the library API, as usual. Adjust the names and prototypes of the assembly functions to align more closely with the rest of the library code. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20251109234726.638437-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2025-11-11lib/crypto: polyval: Add POLYVAL libraryEric Biggers
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>
2025-04-28crypto: polyval-generic - Use API partial block handlingHerbert Xu
Use the Crypto API partial block handling. The accelerated export format on x86/arm64 is easier to use so switch the generic polyval algorithm to use that format instead. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-06-10crypto: x86/polyval - Add PCLMULQDQ accelerated implementation of POLYVALNathan Huckleberry
Add hardware accelerated version of POLYVAL for x86-64 CPUs with PCLMULQDQ support. This implementation is accelerated using PCLMULQDQ instructions to perform the finite field computations. For added efficiency, 8 blocks of the message are processed simultaneously by precomputing the first 8 powers of the key. Schoolbook multiplication is used instead of Karatsuba multiplication because it was found to be slightly faster on x86-64 machines. Montgomery reduction must be used instead of Barrett reduction due to the difference in modulus between POLYVAL's field and other finite fields. More information on POLYVAL can be found in the HCTR2 paper: "Length-preserving encryption with HCTR2": https://eprint.iacr.org/2021/1441.pdf Signed-off-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-06-10crypto: polyval - Add POLYVAL supportNathan Huckleberry
Add support for POLYVAL, an ε-Δ-universal hash function similar to GHASH. This patch only uses POLYVAL as a component to implement HCTR2 mode. It should be noted that POLYVAL was originally specified for use in AES-GCM-SIV (RFC 8452), but the kernel does not currently support this mode. POLYVAL is implemented as an shash algorithm. The implementation is modified from ghash-generic.c. For more information on POLYVAL see: Length-preserving encryption with HCTR2: https://eprint.iacr.org/2021/1441.pdf AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption: https://datatracker.ietf.org/doc/html/rfc8452 Signed-off-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>