linux-stable/lib/crypto/chacha.c
Randy Dunlap b2a4411aca crypto: doc - fix kernel-doc notation in chacha.c and af_alg.c
Fix function name in chacha.c kernel-doc comment to remove a warning.

Convert af_alg.c to kernel-doc notation to eliminate many kernel-doc
warnings.

../lib/crypto/chacha.c:77: warning: expecting prototype for chacha_block(). Prototype was for chacha_block_generic() instead
chacha.c:104: warning: Excess function parameter 'out' description in 'hchacha_block_generic'

af_alg.c:498: warning: Function parameter or member 'sk' not described in 'af_alg_alloc_tsgl'
../crypto/af_alg.c:539: warning: expecting prototype for aead_count_tsgl(). Prototype was for af_alg_count_tsgl() instead
../crypto/af_alg.c:596: warning: expecting prototype for aead_pull_tsgl(). Prototype was for af_alg_pull_tsgl() instead
af_alg.c:663: warning: Function parameter or member 'areq' not described in 'af_alg_free_areq_sgls'
af_alg.c:700: warning: Function parameter or member 'sk' not described in 'af_alg_wait_for_wmem'
af_alg.c:700: warning: Function parameter or member 'flags' not described in 'af_alg_wait_for_wmem'
af_alg.c:731: warning: Function parameter or member 'sk' not described in 'af_alg_wmem_wakeup'
af_alg.c:757: warning: Function parameter or member 'sk' not described in 'af_alg_wait_for_data'
af_alg.c:757: warning: Function parameter or member 'flags' not described in 'af_alg_wait_for_data'
af_alg.c:757: warning: Function parameter or member 'min' not described in 'af_alg_wait_for_data'
af_alg.c:796: warning: Function parameter or member 'sk' not described in 'af_alg_data_wakeup'
af_alg.c:832: warning: Function parameter or member 'sock' not described in 'af_alg_sendmsg'
af_alg.c:832: warning: Function parameter or member 'msg' not described in 'af_alg_sendmsg'
af_alg.c:832: warning: Function parameter or member 'size' not described in 'af_alg_sendmsg'
af_alg.c:832: warning: Function parameter or member 'ivsize' not described in 'af_alg_sendmsg'
af_alg.c:985: warning: Function parameter or member 'sock' not described in 'af_alg_sendpage'
af_alg.c:985: warning: Function parameter or member 'page' not described in 'af_alg_sendpage'
af_alg.c:985: warning: Function parameter or member 'offset' not described in 'af_alg_sendpage'
af_alg.c:985: warning: Function parameter or member 'size' not described in 'af_alg_sendpage'
af_alg.c:985: warning: Function parameter or member 'flags' not described in 'af_alg_sendpage'
af_alg.c:1040: warning: Function parameter or member 'areq' not described in 'af_alg_free_resources'
af_alg.c:1059: warning: Function parameter or member '_req' not described in 'af_alg_async_cb'
af_alg.c:1059: warning: Function parameter or member 'err' not described in 'af_alg_async_cb'
af_alg.c:1083: warning: Function parameter or member 'file' not described in 'af_alg_poll'
af_alg.c:1083: warning: Function parameter or member 'sock' not described in 'af_alg_poll'
af_alg.c:1083: warning: Function parameter or member 'wait' not described in 'af_alg_poll'
af_alg.c:1114: warning: Function parameter or member 'sk' not described in 'af_alg_alloc_areq'
af_alg.c:1114: warning: Function parameter or member 'areqlen' not described in 'af_alg_alloc_areq'
af_alg.c:1146: warning: Function parameter or member 'sk' not described in 'af_alg_get_rsgl'
af_alg.c:1146: warning: Function parameter or member 'msg' not described in 'af_alg_get_rsgl'
af_alg.c:1146: warning: Function parameter or member 'flags' not described in 'af_alg_get_rsgl'
af_alg.c:1146: warning: Function parameter or member 'areq' not described in 'af_alg_get_rsgl'
af_alg.c:1146: warning: Function parameter or member 'maxsize' not described in 'af_alg_get_rsgl'
af_alg.c:1146: warning: Function parameter or member 'outlen' not described in 'af_alg_get_rsgl'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-04-22 17:31:29 +10:00

114 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* The "hash function" used as the core of the ChaCha stream cipher (RFC7539)
*
* Copyright (C) 2015 Martin Willi
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/bitops.h>
#include <linux/string.h>
#include <asm/unaligned.h>
#include <crypto/chacha.h>
static void chacha_permute(u32 *x, int nrounds)
{
int i;
/* whitelist the allowed round counts */
WARN_ON_ONCE(nrounds != 20 && nrounds != 12);
for (i = 0; i < nrounds; i += 2) {
x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 16);
x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 16);
x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 16);
x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 16);
x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 12);
x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 12);
x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 12);
x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 12);
x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 8);
x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 8);
x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 8);
x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 8);
x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 7);
x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 7);
x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 7);
x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 7);
x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 16);
x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 16);
x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 16);
x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 16);
x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 12);
x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 12);
x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 12);
x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 12);
x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 8);
x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 8);
x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 8);
x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 8);
x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 7);
x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 7);
x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 7);
x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 7);
}
}
/**
* chacha_block_generic - generate one keystream block and increment block counter
* @state: input state matrix (16 32-bit words)
* @stream: output keystream block (64 bytes)
* @nrounds: number of rounds (20 or 12; 20 is recommended)
*
* This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
* The caller has already converted the endianness of the input. This function
* also handles incrementing the block counter in the input matrix.
*/
void chacha_block_generic(u32 *state, u8 *stream, int nrounds)
{
u32 x[16];
int i;
memcpy(x, state, 64);
chacha_permute(x, nrounds);
for (i = 0; i < ARRAY_SIZE(x); i++)
put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
state[12]++;
}
EXPORT_SYMBOL(chacha_block_generic);
/**
* hchacha_block_generic - abbreviated ChaCha core, for XChaCha
* @state: input state matrix (16 32-bit words)
* @stream: output (8 32-bit words)
* @nrounds: number of rounds (20 or 12; 20 is recommended)
*
* HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
* towards XChaCha (see https://cr.yp.to/snuffle/xsalsa-20081128.pdf). HChaCha
* skips the final addition of the initial state, and outputs only certain words
* of the state. It should not be used for streaming directly.
*/
void hchacha_block_generic(const u32 *state, u32 *stream, int nrounds)
{
u32 x[16];
memcpy(x, state, 64);
chacha_permute(x, nrounds);
memcpy(&stream[0], &x[0], 16);
memcpy(&stream[4], &x[12], 16);
}
EXPORT_SYMBOL(hchacha_block_generic);