forked from Minki/linux
2aaba014b5
<linux/cryptohash.h> sounds very generic and important, like it's the header to include if you're doing cryptographic hashing in the kernel. But actually it only includes the library implementation of the SHA-1 compression function (not even the full SHA-1). This should basically never be used anymore; SHA-1 is no longer considered secure, and there are much better ways to do cryptographic hashing in the kernel. Most files that include this header don't actually need it. So in preparation for removing it, remove all these unneeded includes of it. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
115 lines
3.7 KiB
C
115 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* The "hash function" used as the core of 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/bug.h>
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/bitops.h>
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#include <linux/string.h>
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#include <asm/unaligned.h>
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#include <crypto/chacha.h>
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static void chacha_permute(u32 *x, int nrounds)
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{
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int i;
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/* whitelist the allowed round counts */
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WARN_ON_ONCE(nrounds != 20 && nrounds != 12);
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for (i = 0; i < nrounds; i += 2) {
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x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 16);
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x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 16);
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x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 16);
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x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 16);
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x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 12);
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x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 12);
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x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 12);
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x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 12);
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x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 8);
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x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 8);
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x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 8);
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x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 8);
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x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 7);
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x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 7);
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x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 7);
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x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 7);
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x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 16);
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x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 16);
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x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 16);
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x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 16);
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x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 12);
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x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 12);
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x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 12);
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x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 12);
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x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 8);
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x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 8);
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x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 8);
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x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 8);
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x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 7);
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x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 7);
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x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 7);
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x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 7);
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}
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}
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/**
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* chacha_block - generate one keystream block and increment block counter
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* @state: input state matrix (16 32-bit words)
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* @stream: output keystream block (64 bytes)
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* @nrounds: number of rounds (20 or 12; 20 is recommended)
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*
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* This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
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* The caller has already converted the endianness of the input. This function
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* also handles incrementing the block counter in the input matrix.
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*/
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void chacha_block_generic(u32 *state, u8 *stream, int nrounds)
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{
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u32 x[16];
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int i;
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memcpy(x, state, 64);
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chacha_permute(x, nrounds);
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for (i = 0; i < ARRAY_SIZE(x); i++)
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put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
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state[12]++;
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}
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EXPORT_SYMBOL(chacha_block_generic);
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/**
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* hchacha_block_generic - abbreviated ChaCha core, for XChaCha
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* @state: input state matrix (16 32-bit words)
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* @out: output (8 32-bit words)
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* @nrounds: number of rounds (20 or 12; 20 is recommended)
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*
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* HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
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* towards XChaCha (see https://cr.yp.to/snuffle/xsalsa-20081128.pdf). HChaCha
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* skips the final addition of the initial state, and outputs only certain words
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* of the state. It should not be used for streaming directly.
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*/
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void hchacha_block_generic(const u32 *state, u32 *stream, int nrounds)
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{
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u32 x[16];
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memcpy(x, state, 64);
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chacha_permute(x, nrounds);
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memcpy(&stream[0], &x[0], 16);
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memcpy(&stream[4], &x[12], 16);
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}
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EXPORT_SYMBOL(hchacha_block_generic);
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