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/crypto.h>
15#include <linux/module.h>
16#include <linux/string.h>
17#include <asm/unaligned.h>
18
19typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
20
21static inline int sm3_base_init(struct shash_desc *desc)
22{
23	struct sm3_state *sctx = shash_desc_ctx(desc);
24
25	sctx->state[0] = SM3_IVA;
26	sctx->state[1] = SM3_IVB;
27	sctx->state[2] = SM3_IVC;
28	sctx->state[3] = SM3_IVD;
29	sctx->state[4] = SM3_IVE;
30	sctx->state[5] = SM3_IVF;
31	sctx->state[6] = SM3_IVG;
32	sctx->state[7] = SM3_IVH;
33	sctx->count = 0;
34
35	return 0;
36}
37
38static inline int sm3_base_do_update(struct shash_desc *desc,
39				      const u8 *data,
40				      unsigned int len,
41				      sm3_block_fn *block_fn)
42{
43	struct sm3_state *sctx = shash_desc_ctx(desc);
44	unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
45
46	sctx->count += len;
47
48	if (unlikely((partial + len) >= SM3_BLOCK_SIZE)) {
49		int blocks;
50
51		if (partial) {
52			int p = SM3_BLOCK_SIZE - partial;
53
54			memcpy(sctx->buffer + partial, data, p);
55			data += p;
56			len -= p;
57
58			block_fn(sctx, sctx->buffer, 1);
59		}
60
61		blocks = len / SM3_BLOCK_SIZE;
62		len %= SM3_BLOCK_SIZE;
63
64		if (blocks) {
65			block_fn(sctx, data, blocks);
66			data += blocks * SM3_BLOCK_SIZE;
67		}
68		partial = 0;
69	}
70	if (len)
71		memcpy(sctx->buffer + partial, data, len);
72
73	return 0;
74}
75
76static inline int sm3_base_do_finalize(struct shash_desc *desc,
77					sm3_block_fn *block_fn)
78{
79	const int bit_offset = SM3_BLOCK_SIZE - sizeof(__be64);
80	struct sm3_state *sctx = shash_desc_ctx(desc);
81	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
82	unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
83
84	sctx->buffer[partial++] = 0x80;
85	if (partial > bit_offset) {
86		memset(sctx->buffer + partial, 0x0, SM3_BLOCK_SIZE - partial);
87		partial = 0;
88
89		block_fn(sctx, sctx->buffer, 1);
90	}
91
92	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
93	*bits = cpu_to_be64(sctx->count << 3);
94	block_fn(sctx, sctx->buffer, 1);
95
96	return 0;
97}
98
99static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
100{
101	struct sm3_state *sctx = shash_desc_ctx(desc);
102	__be32 *digest = (__be32 *)out;
103	int i;
104
105	for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
106		put_unaligned_be32(sctx->state[i], digest++);
107
108	memzero_explicit(sctx, sizeof(*sctx));
109	return 0;
110}
111
112#endif /* _CRYPTO_SM3_BASE_H */
113