xref: /openbmc/linux/include/crypto/sm3_base.h (revision b830f94f)
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 #include <crypto/internal/hash.h>
10 #include <crypto/sm3.h>
11 #include <linux/crypto.h>
12 #include <linux/module.h>
13 #include <asm/unaligned.h>
14 
15 typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
16 
17 static inline int sm3_base_init(struct shash_desc *desc)
18 {
19 	struct sm3_state *sctx = shash_desc_ctx(desc);
20 
21 	sctx->state[0] = SM3_IVA;
22 	sctx->state[1] = SM3_IVB;
23 	sctx->state[2] = SM3_IVC;
24 	sctx->state[3] = SM3_IVD;
25 	sctx->state[4] = SM3_IVE;
26 	sctx->state[5] = SM3_IVF;
27 	sctx->state[6] = SM3_IVG;
28 	sctx->state[7] = SM3_IVH;
29 	sctx->count = 0;
30 
31 	return 0;
32 }
33 
34 static inline int sm3_base_do_update(struct shash_desc *desc,
35 				      const u8 *data,
36 				      unsigned int len,
37 				      sm3_block_fn *block_fn)
38 {
39 	struct sm3_state *sctx = shash_desc_ctx(desc);
40 	unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
41 
42 	sctx->count += len;
43 
44 	if (unlikely((partial + len) >= SM3_BLOCK_SIZE)) {
45 		int blocks;
46 
47 		if (partial) {
48 			int p = SM3_BLOCK_SIZE - partial;
49 
50 			memcpy(sctx->buffer + partial, data, p);
51 			data += p;
52 			len -= p;
53 
54 			block_fn(sctx, sctx->buffer, 1);
55 		}
56 
57 		blocks = len / SM3_BLOCK_SIZE;
58 		len %= SM3_BLOCK_SIZE;
59 
60 		if (blocks) {
61 			block_fn(sctx, data, blocks);
62 			data += blocks * SM3_BLOCK_SIZE;
63 		}
64 		partial = 0;
65 	}
66 	if (len)
67 		memcpy(sctx->buffer + partial, data, len);
68 
69 	return 0;
70 }
71 
72 static inline int sm3_base_do_finalize(struct shash_desc *desc,
73 					sm3_block_fn *block_fn)
74 {
75 	const int bit_offset = SM3_BLOCK_SIZE - sizeof(__be64);
76 	struct sm3_state *sctx = shash_desc_ctx(desc);
77 	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
78 	unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
79 
80 	sctx->buffer[partial++] = 0x80;
81 	if (partial > bit_offset) {
82 		memset(sctx->buffer + partial, 0x0, SM3_BLOCK_SIZE - partial);
83 		partial = 0;
84 
85 		block_fn(sctx, sctx->buffer, 1);
86 	}
87 
88 	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
89 	*bits = cpu_to_be64(sctx->count << 3);
90 	block_fn(sctx, sctx->buffer, 1);
91 
92 	return 0;
93 }
94 
95 static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
96 {
97 	struct sm3_state *sctx = shash_desc_ctx(desc);
98 	__be32 *digest = (__be32 *)out;
99 	int i;
100 
101 	for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
102 		put_unaligned_be32(sctx->state[i], digest++);
103 
104 	*sctx = (struct sm3_state){};
105 	return 0;
106 }
107