linux-stable/include/crypto/sm3_base.h
Arvind Sankar 458c0480dc crypto: hash - Use memzero_explicit() for clearing state
Without the barrier_data() inside memzero_explicit(), the compiler may
optimize away the state-clearing if it can tell that the state is not
used afterwards.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:35:03 +11:00

112 lines
2.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* sm3_base.h - core logic for SM3 implementations
*
* Copyright (C) 2017 ARM Limited or its affiliates.
* Written by Gilad Ben-Yossef <gilad@benyossef.com>
*/
#ifndef _CRYPTO_SM3_BASE_H
#define _CRYPTO_SM3_BASE_H
#include <crypto/internal/hash.h>
#include <crypto/sm3.h>
#include <linux/crypto.h>
#include <linux/module.h>
#include <linux/string.h>
#include <asm/unaligned.h>
typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
static inline int sm3_base_init(struct shash_desc *desc)
{
struct sm3_state *sctx = shash_desc_ctx(desc);
sctx->state[0] = SM3_IVA;
sctx->state[1] = SM3_IVB;
sctx->state[2] = SM3_IVC;
sctx->state[3] = SM3_IVD;
sctx->state[4] = SM3_IVE;
sctx->state[5] = SM3_IVF;
sctx->state[6] = SM3_IVG;
sctx->state[7] = SM3_IVH;
sctx->count = 0;
return 0;
}
static inline int sm3_base_do_update(struct shash_desc *desc,
const u8 *data,
unsigned int len,
sm3_block_fn *block_fn)
{
struct sm3_state *sctx = shash_desc_ctx(desc);
unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
sctx->count += len;
if (unlikely((partial + len) >= SM3_BLOCK_SIZE)) {
int blocks;
if (partial) {
int p = SM3_BLOCK_SIZE - partial;
memcpy(sctx->buffer + partial, data, p);
data += p;
len -= p;
block_fn(sctx, sctx->buffer, 1);
}
blocks = len / SM3_BLOCK_SIZE;
len %= SM3_BLOCK_SIZE;
if (blocks) {
block_fn(sctx, data, blocks);
data += blocks * SM3_BLOCK_SIZE;
}
partial = 0;
}
if (len)
memcpy(sctx->buffer + partial, data, len);
return 0;
}
static inline int sm3_base_do_finalize(struct shash_desc *desc,
sm3_block_fn *block_fn)
{
const int bit_offset = SM3_BLOCK_SIZE - sizeof(__be64);
struct sm3_state *sctx = shash_desc_ctx(desc);
__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
sctx->buffer[partial++] = 0x80;
if (partial > bit_offset) {
memset(sctx->buffer + partial, 0x0, SM3_BLOCK_SIZE - partial);
partial = 0;
block_fn(sctx, sctx->buffer, 1);
}
memset(sctx->buffer + partial, 0x0, bit_offset - partial);
*bits = cpu_to_be64(sctx->count << 3);
block_fn(sctx, sctx->buffer, 1);
return 0;
}
static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
{
struct sm3_state *sctx = shash_desc_ctx(desc);
__be32 *digest = (__be32 *)out;
int i;
for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
put_unaligned_be32(sctx->state[i], digest++);
memzero_explicit(sctx, sizeof(*sctx));
return 0;
}
#endif /* _CRYPTO_SM3_BASE_H */