kernel/git/stable/linux.git/include/crypto/internal/sha2.h, branch master

lib/crypto: sha256: Consolidate into single module

2025-07-04T17:23:11+00:00

Consolidate the CPU-based SHA-256 code into a single module, following what I did with SHA-512: - Each arch now provides a header file lib/crypto/$(SRCARCH)/sha256.h, replacing lib/crypto/$(SRCARCH)/sha256.c. The header defines sha256_blocks() and optionally sha256_mod_init_arch(). It is included by lib/crypto/sha256.c, and thus the code gets built into the single libsha256 module, with proper inlining and dead code elimination. - sha256_blocks_generic() is moved from lib/crypto/sha256-generic.c into lib/crypto/sha256.c. It's now a static function marked with __maybe_unused, so the compiler automatically eliminates it in any cases where it's not used. - Whether arch-optimized SHA-256 is buildable is now controlled centrally by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig. The conditions for enabling it remain the same as before, and it remains enabled by default. - Any additional arch-specific translation units for the optimized SHA-256 code (such as assembly files) are now compiled by lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250630160645.3198-13-ebiggers@kernel.org Signed-off-by: Eric Biggers

lib/crypto: sha256: Remove sha256_is_arch_optimized()

2025-07-04T17:23:11+00:00

Remove sha256_is_arch_optimized(), since it is no longer used. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250630160645.3198-12-ebiggers@kernel.org Signed-off-by: Eric Biggers

lib/crypto: sha256: Propagate sha256_block_state type to implementations

2025-07-04T17:22:57+00:00

The previous commit made the SHA-256 compression function state be strongly typed, but it wasn't propagated all the way down to the implementations of it. Do that now. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250630160645.3198-8-ebiggers@kernel.org Signed-off-by: Eric Biggers

lib/crypto: sha256: Remove sha256_blocks_simd()

2025-07-04T17:18:53+00:00

Instead of having both sha256_blocks_arch() and sha256_blocks_simd(), instead have just sha256_blocks_arch() which uses the most efficient implementation that is available in the calling context. This is simpler, as it reduces the API surface. It's also safer, since sha256_blocks_arch() just works in all contexts, including contexts where the FPU/SIMD/vector registers cannot be used. This doesn't mean that SHA-256 computations *should* be done in such contexts, but rather we should just do the right thing instead of corrupting a random task's registers. Eliminating this footgun and simplifying the code is well worth the very small performance cost of doing the check. Note: in the case of arm and arm64, what used to be sha256_blocks_arch() is renamed back to its original name of sha256_block_data_order(). sha256_blocks_arch() is now used for the higher-level dispatch function. This renaming also required an update to lib/crypto/arm64/sha512.h, since sha2-armv8.pl is shared by both SHA-256 and SHA-512. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250630160645.3198-5-ebiggers@kernel.org Signed-off-by: Eric Biggers

lib/crypto: sha256: Mark sha256_choose_blocks as __always_inline

2025-06-20T20:22:03+00:00

When the compiler chooses to not inline sha256_choose_blocks() in the purgatory code, it fails to link against the missing CPU specific version: x86_64-linux-ld: arch/x86/purgatory/purgatory.ro: in function `sha256_choose_blocks.part.0': sha256.c:(.text+0x6a6): undefined reference to `irq_fpu_usable' sha256.c:(.text+0x6c7): undefined reference to `sha256_blocks_arch' sha256.c:(.text+0x6cc): undefined reference to `sha256_blocks_simd' Mark this function as __always_inline to prevent this, same as sha256_finup(). Fixes: 5b90a779bc54 ("crypto: lib/sha256 - Add helpers for block-based shash") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20250620191952.1867578-1-arnd@kernel.org Signed-off-by: Eric Biggers

crypto: lib/sha256 - Use generic block helper

2025-05-05T10:20:45+00:00

Use the BLOCK_HASH_UPDATE_BLOCKS helper instead of duplicating partial block handling. Also remove the unused lib/sha256 force-generic interface. Signed-off-by: Herbert Xu

crypto: lib/sha256 - Add helpers for block-based shash

2025-05-05T10:20:45+00:00

Add an internal sha256_finup helper and move the finalisation code from __sha256_final into it. Also add sha256_choose_blocks and CRYPTO_ARCH_HAVE_LIB_SHA256_SIMD so that the Crypto API can use the SIMD block function unconditionally. The Crypto API must not be used in hard IRQs and there is no reason to have a fallback path for hardirqs. Signed-off-by: Herbert Xu

crypto: sha256 - support arch-optimized lib and expose through shash

2025-05-05T05:38:12+00:00

As has been done for various other algorithms, rework the design of the SHA-256 library to support arch-optimized implementations, and make crypto/sha256.c expose both generic and arch-optimized shash algorithms that wrap the library functions. This allows users of the SHA-256 library functions to take advantage of the arch-optimized code, and this makes it much simpler to integrate SHA-256 for each architecture. Note that sha256_base.h is not used in the new design. It will be removed once all the architecture-specific code has been updated. Move the generic block function into its own module to avoid a circular dependency from libsha256.ko => sha256-$ARCH.ko => libsha256.ko. Signed-off-by: Eric Biggers Add export and import functions to maintain existing export format. Signed-off-by: Herbert Xu