/*
* sha256_base.h - core logic for SHA-256 implementations
*
* Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <linux/crypto.h>
#include <linux/module.h>
#include <asm/unaligned.h>
typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
int blocks);
static inline int sha224_base_init(struct shash_desc *desc)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
return sha224_init(sctx);
}
static inline int sha256_base_init(struct shash_desc *desc)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
return sha256_init(sctx);
}
static inline int sha256_base_do_update(struct shash_desc *desc,
const u8 *data,
unsigned int len,
sha256_block_fn *block_fn)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
sctx->count += len;
if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
int blocks;
if (partial) {
int p = SHA256_BLOCK_SIZE - partial;
memcpy(sctx->buf + partial, data, p);
data += p;
len -= p;
block_fn(sctx, sctx->buf, 1);
}
blocks = len / SHA256_BLOCK_SIZE;
len %= SHA256_BLOCK_SIZE;
if (blocks) {
block_fn(sctx, data, blocks);
data += blocks * SHA256_BLOCK_SIZE;
}
partial = 0;
}
if (len)
memcpy(sctx->buf + partial, data, len);
return 0;
}
static inline int sha256_base_do_finalize(struct shash_desc *desc,
sha256_block_fn *block_fn)
{
const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
struct sha256_state *sctx = shash_desc_ctx(desc);
__be64 *bits = (__be64 *)(sctx->buf + bit_offset);
unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
sctx->buf[partial++] = 0x80;
if (partial > bit_offset) {
memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
partial = 0;
block_fn(sctx, sctx->buf, 1);
}
memset(sctx->buf + partial, 0x0, bit_offset - partial);
*bits = cpu_to_be64(sctx->count << 3);
block_fn(sctx, sctx->buf, 1);
return 0;
}
static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
{
unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
struct sha256_state *sctx = shash_desc_ctx(desc);
__be32 *digest = (__be32 *)out;
int i;
for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
put_unaligned_be32(sctx->state[i], digest++);
*sctx = (struct sha256_state){};
return 0;
}
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