1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * sha256_base.h - core logic for SHA-256 implementations
4 *
5 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */
7
8 #ifndef _CRYPTO_SHA256_BASE_H
9 #define _CRYPTO_SHA256_BASE_H
10
11 #include <asm/byteorder.h>
12 #include <asm/unaligned.h>
13 #include <crypto/internal/hash.h>
14 #include <crypto/sha2.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17
18 typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
19 int blocks);
20
21 static inline int sha224_base_init(struct shash_desc *desc)
22 {
23 struct sha256_state *sctx = shash_desc_ctx(desc);
24
25 sha224_init(sctx);
26 return 0;
27 }
28
29 static inline int sha256_base_init(struct shash_desc *desc)
30 {
31 struct sha256_state *sctx = shash_desc_ctx(desc);
32
33 sha256_init(sctx);
34 return 0;
35 }
36
37 static inline int lib_sha256_base_do_update(struct sha256_state *sctx,
38 const u8 *data,
39 unsigned int len,
40 sha256_block_fn *block_fn)
41 {
42 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
43
44 sctx->count += len;
45
46 if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
47 int blocks;
48
49 if (partial) {
50 int p = SHA256_BLOCK_SIZE - partial;
51
52 memcpy(sctx->buf + partial, data, p);
53 data += p;
54 len -= p;
55
56 block_fn(sctx, sctx->buf, 1);
57 }
58
59 blocks = len / SHA256_BLOCK_SIZE;
60 len %= SHA256_BLOCK_SIZE;
61
62 if (blocks) {
63 block_fn(sctx, data, blocks);
64 data += blocks * SHA256_BLOCK_SIZE;
65 }
66 partial = 0;
67 }
68 if (len)
69 memcpy(sctx->buf + partial, data, len);
70
71 return 0;
72 }
73
74 static inline int sha256_base_do_update(struct shash_desc *desc,
75 const u8 *data,
76 unsigned int len,
77 sha256_block_fn *block_fn)
78 {
79 struct sha256_state *sctx = shash_desc_ctx(desc);
80
81 return lib_sha256_base_do_update(sctx, data, len, block_fn);
82 }
83
84 static inline int lib_sha256_base_do_finalize(struct sha256_state *sctx,
85 sha256_block_fn *block_fn)
86 {
87 const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
88 __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
89 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
90
91 sctx->buf[partial++] = 0x80;
92 if (partial > bit_offset) {
93 memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
94 partial = 0;
95
96 block_fn(sctx, sctx->buf, 1);
97 }
98
99 memset(sctx->buf + partial, 0x0, bit_offset - partial);
100 *bits = cpu_to_be64(sctx->count << 3);
101 block_fn(sctx, sctx->buf, 1);
102
103 return 0;
104 }
105
106 static inline int sha256_base_do_finalize(struct shash_desc *desc,
107 sha256_block_fn *block_fn)
108 {
109 struct sha256_state *sctx = shash_desc_ctx(desc);
110
111 return lib_sha256_base_do_finalize(sctx, block_fn);
112 }
113
114 static inline int lib_sha256_base_finish(struct sha256_state *sctx, u8 *out,
115 unsigned int digest_size)
116 {
117 __be32 *digest = (__be32 *)out;
118 int i;
119
120 for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
121 put_unaligned_be32(sctx->state[i], digest++);
122
123 memzero_explicit(sctx, sizeof(*sctx));
124 return 0;
125 }
126
127 static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
128 {
129 unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
130 struct sha256_state *sctx = shash_desc_ctx(desc);
131
132 return lib_sha256_base_finish(sctx, out, digest_size);
133 }
134
135 #endif /* _CRYPTO_SHA256_BASE_H */
136
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.