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/math.h>
15 #include <linux/module.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/unaligned.h>
19 
20 typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
21 
22 static inline int sm3_base_init(struct shash_desc *desc)
23 {
24 	sm3_init(shash_desc_ctx(desc));
25 	return 0;
26 }
27 
28 static inline int sm3_base_do_update_blocks(struct shash_desc *desc,
29 					    const u8 *data, unsigned int len,
30 					    sm3_block_fn *block_fn)
31 {
32 	unsigned int remain = len - round_down(len, SM3_BLOCK_SIZE);
33 	struct sm3_state *sctx = shash_desc_ctx(desc);
34 
35 	sctx->count += len - remain;
36 	block_fn(sctx, data, len / SM3_BLOCK_SIZE);
37 	return remain;
38 }
39 
40 static inline int sm3_base_do_finup(struct shash_desc *desc,
41 				    const u8 *src, unsigned int len,
42 				    sm3_block_fn *block_fn)
43 {
44 	unsigned int bit_offset = SM3_BLOCK_SIZE / 8 - 1;
45 	struct sm3_state *sctx = shash_desc_ctx(desc);
46 	union {
47 		__be64 b64[SM3_BLOCK_SIZE / 4];
48 		u8 u8[SM3_BLOCK_SIZE * 2];
49 	} block = {};
50 
51 	if (len >= SM3_BLOCK_SIZE) {
52 		int remain;
53 
54 		remain = sm3_base_do_update_blocks(desc, src, len, block_fn);
55 		src += len - remain;
56 		len = remain;
57 	}
58 
59 	if (len >= bit_offset * 8)
60 		bit_offset += SM3_BLOCK_SIZE / 8;
61 	memcpy(&block, src, len);
62 	block.u8[len] = 0x80;
63 	sctx->count += len;
64 	block.b64[bit_offset] = cpu_to_be64(sctx->count << 3);
65 	block_fn(sctx, block.u8, (bit_offset + 1) * 8 / SM3_BLOCK_SIZE);
66 	memzero_explicit(&block, sizeof(block));
67 
68 	return 0;
69 }
70 
71 static inline int sm3_base_finish(struct shash_desc *desc, u8 *out)
72 {
73 	struct sm3_state *sctx = shash_desc_ctx(desc);
74 	__be32 *digest = (__be32 *)out;
75 	int i;
76 
77 	for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
78 		put_unaligned_be32(sctx->state[i], digest++);
79 	return 0;
80 }
81 
82 #endif /* _CRYPTO_SM3_BASE_H */
83