xref: /openbmc/linux/include/crypto/sha1_base.h (revision 2cf1c348)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * sha1_base.h - core logic for SHA-1 implementations
4  *
5  * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
6  */
7 
8 #ifndef _CRYPTO_SHA1_BASE_H
9 #define _CRYPTO_SHA1_BASE_H
10 
11 #include <crypto/internal/hash.h>
12 #include <crypto/sha1.h>
13 #include <linux/crypto.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16 
17 #include <asm/unaligned.h>
18 
19 typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
20 
21 static inline int sha1_base_init(struct shash_desc *desc)
22 {
23 	struct sha1_state *sctx = shash_desc_ctx(desc);
24 
25 	sctx->state[0] = SHA1_H0;
26 	sctx->state[1] = SHA1_H1;
27 	sctx->state[2] = SHA1_H2;
28 	sctx->state[3] = SHA1_H3;
29 	sctx->state[4] = SHA1_H4;
30 	sctx->count = 0;
31 
32 	return 0;
33 }
34 
35 static inline int sha1_base_do_update(struct shash_desc *desc,
36 				      const u8 *data,
37 				      unsigned int len,
38 				      sha1_block_fn *block_fn)
39 {
40 	struct sha1_state *sctx = shash_desc_ctx(desc);
41 	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
42 
43 	sctx->count += len;
44 
45 	if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
46 		int blocks;
47 
48 		if (partial) {
49 			int p = SHA1_BLOCK_SIZE - partial;
50 
51 			memcpy(sctx->buffer + partial, data, p);
52 			data += p;
53 			len -= p;
54 
55 			block_fn(sctx, sctx->buffer, 1);
56 		}
57 
58 		blocks = len / SHA1_BLOCK_SIZE;
59 		len %= SHA1_BLOCK_SIZE;
60 
61 		if (blocks) {
62 			block_fn(sctx, data, blocks);
63 			data += blocks * SHA1_BLOCK_SIZE;
64 		}
65 		partial = 0;
66 	}
67 	if (len)
68 		memcpy(sctx->buffer + partial, data, len);
69 
70 	return 0;
71 }
72 
73 static inline int sha1_base_do_finalize(struct shash_desc *desc,
74 					sha1_block_fn *block_fn)
75 {
76 	const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
77 	struct sha1_state *sctx = shash_desc_ctx(desc);
78 	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
79 	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
80 
81 	sctx->buffer[partial++] = 0x80;
82 	if (partial > bit_offset) {
83 		memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
84 		partial = 0;
85 
86 		block_fn(sctx, sctx->buffer, 1);
87 	}
88 
89 	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
90 	*bits = cpu_to_be64(sctx->count << 3);
91 	block_fn(sctx, sctx->buffer, 1);
92 
93 	return 0;
94 }
95 
96 static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
97 {
98 	struct sha1_state *sctx = shash_desc_ctx(desc);
99 	__be32 *digest = (__be32 *)out;
100 	int i;
101 
102 	for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
103 		put_unaligned_be32(sctx->state[i], digest++);
104 
105 	memzero_explicit(sctx, sizeof(*sctx));
106 	return 0;
107 }
108 
109 #endif /* _CRYPTO_SHA1_BASE_H */
110