1 /*
2  * sm3_base.h - core logic for SM3 implementations
3  *
4  * Copyright (C) 2017 ARM Limited or its affiliates.
5  * Written by Gilad Ben-Yossef <gilad@benyossef.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <crypto/internal/hash.h>
21 #include <crypto/sm3.h>
22 #include <linux/crypto.h>
23 #include <linux/module.h>
24 #include <asm/unaligned.h>
25 
26 typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
27 
sm3_base_init(struct shash_desc * desc)28 static inline int sm3_base_init(struct shash_desc *desc)
29 {
30 	struct sm3_state *sctx = shash_desc_ctx(desc);
31 
32 	sctx->state[0] = SM3_IVA;
33 	sctx->state[1] = SM3_IVB;
34 	sctx->state[2] = SM3_IVC;
35 	sctx->state[3] = SM3_IVD;
36 	sctx->state[4] = SM3_IVE;
37 	sctx->state[5] = SM3_IVF;
38 	sctx->state[6] = SM3_IVG;
39 	sctx->state[7] = SM3_IVH;
40 	sctx->count = 0;
41 
42 	return 0;
43 }
44 
sm3_base_do_update(struct shash_desc * desc,const u8 * data,unsigned int len,sm3_block_fn * block_fn)45 static inline int sm3_base_do_update(struct shash_desc *desc,
46 				      const u8 *data,
47 				      unsigned int len,
48 				      sm3_block_fn *block_fn)
49 {
50 	struct sm3_state *sctx = shash_desc_ctx(desc);
51 	unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
52 
53 	sctx->count += len;
54 
55 	if (unlikely((partial + len) >= SM3_BLOCK_SIZE)) {
56 		int blocks;
57 
58 		if (partial) {
59 			int p = SM3_BLOCK_SIZE - partial;
60 
61 			memcpy(sctx->buffer + partial, data, p);
62 			data += p;
63 			len -= p;
64 
65 			block_fn(sctx, sctx->buffer, 1);
66 		}
67 
68 		blocks = len / SM3_BLOCK_SIZE;
69 		len %= SM3_BLOCK_SIZE;
70 
71 		if (blocks) {
72 			block_fn(sctx, data, blocks);
73 			data += blocks * SM3_BLOCK_SIZE;
74 		}
75 		partial = 0;
76 	}
77 	if (len)
78 		memcpy(sctx->buffer + partial, data, len);
79 
80 	return 0;
81 }
82 
sm3_base_do_finalize(struct shash_desc * desc,sm3_block_fn * block_fn)83 static inline int sm3_base_do_finalize(struct shash_desc *desc,
84 					sm3_block_fn *block_fn)
85 {
86 	const int bit_offset = SM3_BLOCK_SIZE - sizeof(__be64);
87 	struct sm3_state *sctx = shash_desc_ctx(desc);
88 	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
89 	unsigned int partial = sctx->count % SM3_BLOCK_SIZE;
90 
91 	sctx->buffer[partial++] = 0x80;
92 	if (partial > bit_offset) {
93 		memset(sctx->buffer + partial, 0x0, SM3_BLOCK_SIZE - partial);
94 		partial = 0;
95 
96 		block_fn(sctx, sctx->buffer, 1);
97 	}
98 
99 	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
100 	*bits = cpu_to_be64(sctx->count << 3);
101 	block_fn(sctx, sctx->buffer, 1);
102 
103 	return 0;
104 }
105 
sm3_base_finish(struct shash_desc * desc,u8 * out)106 static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
107 {
108 	struct sm3_state *sctx = shash_desc_ctx(desc);
109 	__be32 *digest = (__be32 *)out;
110 	int i;
111 
112 	for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
113 		put_unaligned_be32(sctx->state[i], digest++);
114 
115 	*sctx = (struct sm3_state){};
116 	return 0;
117 }
118