sm3_base.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * sm3_base.h - core logic for SM3 implementations
 4 *
 5 * Copyright (C) 2017 ARM Limited or its affiliates.
 6 * Written by Gilad Ben-Yossef <gilad@benyossef.com>
 7 */
 8
 9#ifndef _CRYPTO_SM3_BASE_H
10#define _CRYPTO_SM3_BASE_H
11
12#include <crypto/internal/hash.h>
13#include <crypto/sm3.h>
14#include <linux/math.h>
15#include <linux/module.h>
16#include <linux/string.h>
17#include <linux/types.h>
18#include <linux/unaligned.h>
19
20typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
21
22static inline int sm3_base_init(struct shash_desc *desc)
23{
24	sm3_init(shash_desc_ctx(desc));
25	return 0;
26}
27
28static inline int sm3_base_do_update_blocks(struct shash_desc *desc,
29					    const u8 *data, unsigned int len,
30					    sm3_block_fn *block_fn)
31{
32	unsigned int remain = len - round_down(len, SM3_BLOCK_SIZE);
33	struct sm3_state *sctx = shash_desc_ctx(desc);
34
35	sctx->count += len - remain;
36	block_fn(sctx, data, len / SM3_BLOCK_SIZE);
37	return remain;
38}
39
40static inline int sm3_base_do_finup(struct shash_desc *desc,
41				    const u8 *src, unsigned int len,
42				    sm3_block_fn *block_fn)
43{
44	unsigned int bit_offset = SM3_BLOCK_SIZE / 8 - 1;
45	struct sm3_state *sctx = shash_desc_ctx(desc);
46	union {
47		__be64 b64[SM3_BLOCK_SIZE / 4];
48		u8 u8[SM3_BLOCK_SIZE * 2];
49	} block = {};
50
51	if (len >= SM3_BLOCK_SIZE) {
52		int remain;
53
54		remain = sm3_base_do_update_blocks(desc, src, len, block_fn);
55		src += len - remain;
56		len = remain;
57	}
58
59	if (len >= bit_offset * 8)
60		bit_offset += SM3_BLOCK_SIZE / 8;
61	memcpy(&block, src, len);
62	block.u8[len] = 0x80;
63	sctx->count += len;
64	block.b64[bit_offset] = cpu_to_be64(sctx->count << 3);
65	block_fn(sctx, block.u8, (bit_offset + 1) * 8 / SM3_BLOCK_SIZE);
66	memzero_explicit(&block, sizeof(block));
67
68	return 0;
69}
70
71static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
72{
73	struct sm3_state *sctx = shash_desc_ctx(desc);
74	__be32 *digest = (__be32 *)out;
75	int i;
76
77	for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
78		put_unaligned_be32(sctx->state[i], digest++);
79	return 0;
80}
81
82#endif /* _CRYPTO_SM3_BASE_H */