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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>
37 lines
966 B
C
37 lines
966 B
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* The ChaCha stream cipher (RFC7539)
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*
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* Copyright (C) 2015 Martin Willi
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*/
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/module.h>
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#include <crypto/algapi.h> // for crypto_xor_cpy
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#include <crypto/chacha.h>
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void chacha_crypt_generic(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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/* aligned to potentially speed up crypto_xor() */
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u8 stream[CHACHA_BLOCK_SIZE] __aligned(sizeof(long));
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while (bytes >= CHACHA_BLOCK_SIZE) {
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chacha_block_generic(state, stream, nrounds);
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crypto_xor_cpy(dst, src, stream, CHACHA_BLOCK_SIZE);
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bytes -= CHACHA_BLOCK_SIZE;
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dst += CHACHA_BLOCK_SIZE;
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src += CHACHA_BLOCK_SIZE;
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}
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if (bytes) {
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chacha_block_generic(state, stream, nrounds);
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crypto_xor_cpy(dst, src, stream, bytes);
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}
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}
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EXPORT_SYMBOL(chacha_crypt_generic);
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MODULE_DESCRIPTION("ChaCha stream cipher (RFC7539)");
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MODULE_LICENSE("GPL");
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