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98066f2f89
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 <ebiggers@google.com>
Acked-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
120 lines
3.2 KiB
C
120 lines
3.2 KiB
C
/*
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* ChaCha and HChaCha functions (ARM64 optimized)
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*
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* Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Based on:
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* ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code
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*
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* Copyright (C) 2015 Martin Willi
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <crypto/chacha.h>
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#include <crypto/internal/simd.h>
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#include <linux/jump_label.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/hwcap.h>
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#include <asm/neon.h>
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#include <asm/simd.h>
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asmlinkage void chacha_block_xor_neon(const struct chacha_state *state,
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u8 *dst, const u8 *src, int nrounds);
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asmlinkage void chacha_4block_xor_neon(const struct chacha_state *state,
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u8 *dst, const u8 *src,
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int nrounds, int bytes);
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asmlinkage void hchacha_block_neon(const struct chacha_state *state,
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u32 *out, int nrounds);
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
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static void chacha_doneon(struct chacha_state *state, u8 *dst, const u8 *src,
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int bytes, int nrounds)
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{
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while (bytes > 0) {
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int l = min(bytes, CHACHA_BLOCK_SIZE * 5);
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if (l <= CHACHA_BLOCK_SIZE) {
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u8 buf[CHACHA_BLOCK_SIZE];
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memcpy(buf, src, l);
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chacha_block_xor_neon(state, buf, buf, nrounds);
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memcpy(dst, buf, l);
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state->x[12] += 1;
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break;
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}
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chacha_4block_xor_neon(state, dst, src, nrounds, l);
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bytes -= l;
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src += l;
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dst += l;
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state->x[12] += DIV_ROUND_UP(l, CHACHA_BLOCK_SIZE);
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}
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}
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void hchacha_block_arch(const struct chacha_state *state, u32 *stream,
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int nrounds)
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{
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if (!static_branch_likely(&have_neon) || !crypto_simd_usable()) {
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hchacha_block_generic(state, stream, nrounds);
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} else {
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kernel_neon_begin();
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hchacha_block_neon(state, stream, nrounds);
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kernel_neon_end();
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}
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}
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EXPORT_SYMBOL(hchacha_block_arch);
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void chacha_crypt_arch(struct chacha_state *state, u8 *dst, const u8 *src,
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unsigned int bytes, int nrounds)
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{
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if (!static_branch_likely(&have_neon) || bytes <= CHACHA_BLOCK_SIZE ||
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!crypto_simd_usable())
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return chacha_crypt_generic(state, dst, src, bytes, nrounds);
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do {
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unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
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kernel_neon_begin();
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chacha_doneon(state, dst, src, todo, nrounds);
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kernel_neon_end();
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bytes -= todo;
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src += todo;
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dst += todo;
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} while (bytes);
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}
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EXPORT_SYMBOL(chacha_crypt_arch);
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bool chacha_is_arch_optimized(void)
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{
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return static_key_enabled(&have_neon);
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}
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EXPORT_SYMBOL(chacha_is_arch_optimized);
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static int __init chacha_simd_mod_init(void)
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{
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if (cpu_have_named_feature(ASIMD))
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static_branch_enable(&have_neon);
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return 0;
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}
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subsys_initcall(chacha_simd_mod_init);
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static void __exit chacha_simd_mod_exit(void)
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{
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}
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module_exit(chacha_simd_mod_exit);
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MODULE_DESCRIPTION("ChaCha and HChaCha functions (ARM64 optimized)");
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MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
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MODULE_LICENSE("GPL v2");
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