xref: /openbmc/linux/include/crypto/sm3_base.h (revision 842ed298)
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 
19 typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
20 
21 static 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 
38 static 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 
76 static 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 
99 static 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