xref: /openbmc/linux/include/crypto/sha1_base.h (revision 7d545e77)
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 #include <crypto/internal/hash.h>
9 #include <crypto/sha.h>
10 #include <linux/crypto.h>
11 #include <linux/module.h>
12 
13 #include <asm/unaligned.h>
14 
15 typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
16 
17 static inline int sha1_base_init(struct shash_desc *desc)
18 {
19 	struct sha1_state *sctx = shash_desc_ctx(desc);
20 
21 	sctx->state[0] = SHA1_H0;
22 	sctx->state[1] = SHA1_H1;
23 	sctx->state[2] = SHA1_H2;
24 	sctx->state[3] = SHA1_H3;
25 	sctx->state[4] = SHA1_H4;
26 	sctx->count = 0;
27 
28 	return 0;
29 }
30 
31 static inline int sha1_base_do_update(struct shash_desc *desc,
32 				      const u8 *data,
33 				      unsigned int len,
34 				      sha1_block_fn *block_fn)
35 {
36 	struct sha1_state *sctx = shash_desc_ctx(desc);
37 	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
38 
39 	sctx->count += len;
40 
41 	if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
42 		int blocks;
43 
44 		if (partial) {
45 			int p = SHA1_BLOCK_SIZE - partial;
46 
47 			memcpy(sctx->buffer + partial, data, p);
48 			data += p;
49 			len -= p;
50 
51 			block_fn(sctx, sctx->buffer, 1);
52 		}
53 
54 		blocks = len / SHA1_BLOCK_SIZE;
55 		len %= SHA1_BLOCK_SIZE;
56 
57 		if (blocks) {
58 			block_fn(sctx, data, blocks);
59 			data += blocks * SHA1_BLOCK_SIZE;
60 		}
61 		partial = 0;
62 	}
63 	if (len)
64 		memcpy(sctx->buffer + partial, data, len);
65 
66 	return 0;
67 }
68 
69 static inline int sha1_base_do_finalize(struct shash_desc *desc,
70 					sha1_block_fn *block_fn)
71 {
72 	const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
73 	struct sha1_state *sctx = shash_desc_ctx(desc);
74 	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
75 	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
76 
77 	sctx->buffer[partial++] = 0x80;
78 	if (partial > bit_offset) {
79 		memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
80 		partial = 0;
81 
82 		block_fn(sctx, sctx->buffer, 1);
83 	}
84 
85 	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
86 	*bits = cpu_to_be64(sctx->count << 3);
87 	block_fn(sctx, sctx->buffer, 1);
88 
89 	return 0;
90 }
91 
92 static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
93 {
94 	struct sha1_state *sctx = shash_desc_ctx(desc);
95 	__be32 *digest = (__be32 *)out;
96 	int i;
97 
98 	for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
99 		put_unaligned_be32(sctx->state[i], digest++);
100 
101 	*sctx = (struct sha1_state){};
102 	return 0;
103 }
104