kernel/linux.git/include/crypto/chacha.h, branch v6.18.21

lib/crypto: chacha: Consolidate into single module

2025-08-29T16:50:19+00:00

Consolidate the ChaCha code into a single module (excluding chacha-block-generic.c which remains always built-in for random.c), similar to various other algorithms: - Each arch now provides a header file lib/crypto/$(SRCARCH)/chacha.h, replacing lib/crypto/$(SRCARCH)/chacha*.c. The header defines chacha_crypt_arch() and hchacha_block_arch(). It is included by lib/crypto/chacha.c, and thus the code gets built into the single libchacha module, with improved inlining in some cases. - Whether arch-optimized ChaCha is buildable is now controlled centrally by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig. The conditions for enabling it remain the same as before, and it remains enabled by default. - Any additional arch-specific translation units for the optimized ChaCha code, such as assembly files, are now compiled by lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile. This removes the last use for the Makefile and Kconfig files in the arm64, mips, powerpc, riscv, and s390 subdirectories of lib/crypto/. So also remove those files and the references to them. Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250827151131.27733-7-ebiggers@kernel.org Signed-off-by: Eric Biggers

lib/crypto: chacha: Remove unused function chacha_is_arch_optimized()

2025-08-29T16:50:19+00:00

chacha_is_arch_optimized() is no longer used, so remove it. Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250827151131.27733-4-ebiggers@kernel.org Signed-off-by: Eric Biggers

crypto: lib/chacha - add array bounds to function prototypes

2025-05-12T05:32:53+00:00

Add explicit array bounds to the function prototypes for the parameters that didn't already get handled by the conversion to use chacha_state: - chacha_block_*(): Change 'u8 *out' or 'u8 *stream' to u8 out[CHACHA_BLOCK_SIZE]. - hchacha_block_*(): Change 'u32 *out' or 'u32 *stream' to u32 out[HCHACHA_OUT_WORDS]. - chacha_init(): Change 'const u32 *key' to 'const u32 key[CHACHA_KEY_WORDS]'. Change 'const u8 *iv' to 'const u8 iv[CHACHA_IV_SIZE]'. No functional changes. This just makes it clear when fixed-size arrays are expected. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: lib/chacha - add strongly-typed state zeroization

2025-05-12T05:32:53+00:00

Now that the ChaCha state matrix is strongly-typed, add a helper function chacha_zeroize_state() which zeroizes it. Then convert all applicable callers to use it instead of direct memzero_explicit. No functional changes. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: lib/chacha - strongly type the ChaCha state

2025-05-12T05:32:53+00:00

The ChaCha state matrix is 16 32-bit words. Currently it is represented in the code as a raw u32 array, or even just a pointer to u32. This weak typing is error-prone. Instead, introduce struct chacha_state: struct chacha_state { u32 x[16]; }; Convert all ChaCha and HChaCha functions to use struct chacha_state. No functional changes. Signed-off-by: Eric Biggers Acked-by: Kent Overstreet Signed-off-by: Herbert Xu

crypto: chacha - centralize the skcipher wrappers for arch code

2025-04-07T05:22:28+00:00

Following the example of the crc32 and crc32c code, make the crypto subsystem register both generic and architecture-optimized chacha20, xchacha20, and xchacha12 skcipher algorithms, all implemented on top of the appropriate library functions. This eliminates the need for every architecture to implement the same skcipher glue code. To register the architecture-optimized skciphers only when architecture-optimized code is actually being used, add a function chacha_is_arch_optimized() and make each arch implement it. Change each architecture's ChaCha module_init function to arch_initcall so that the CPU feature detection is guaranteed to run before chacha_is_arch_optimized() gets called by crypto/chacha.c. In the case of s390, remove the CPU feature based module autoloading, which is no longer needed since the module just gets pulled in via function linkage. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: lib/chacha - remove unused arch-specific init support

2025-03-21T09:39:06+00:00

All implementations of chacha_init_arch() just call chacha_init_generic(), so it is pointless. Just delete it, and replace chacha_init() with what was previously chacha_init_generic(). Signed-off-by: Eric Biggers Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

random: early initialization of ChaCha constants

2022-01-06T23:25:25+00:00

Previously, the ChaCha constants for the primary pool were only initialized in crng_initialize_primary(), called by rand_initialize(). However, some randomness is actually extracted from the primary pool beforehand, e.g. by kmem_cache_create(). Therefore, statically initialize the ChaCha constants for the primary pool. Cc: Herbert Xu Cc: "David S. Miller" Cc: Signed-off-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld

random: initialize ChaCha20 constants with correct endianness

2021-04-02T07:28:12+00:00

On big endian CPUs, the ChaCha20-based CRNG is using the wrong endianness for the ChaCha20 constants. This doesn't matter cryptographically, but technically it means it's not ChaCha20 anymore. Fix it to always use the standard constants. Cc: linux-crypto@vger.kernel.org Cc: Andy Lutomirski Cc: Jann Horn Cc: Theodore Ts'o Acked-by: Ard Biesheuvel Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu