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