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 <crypto/internal/hash.h>
12 #include <crypto/sha2.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 (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
20 int blocks);
21
sha224_base_init(struct shash_desc * desc)22 static inline int sha224_base_init(struct shash_desc *desc)
23 {
24 struct sha256_state *sctx = shash_desc_ctx(desc);
25
26 sha224_init(sctx);
27 return 0;
28 }
29
sha256_base_init(struct shash_desc * desc)30 static inline int sha256_base_init(struct shash_desc *desc)
31 {
32 struct sha256_state *sctx = shash_desc_ctx(desc);
33
34 sha256_init(sctx);
35 return 0;
36 }
37
sha256_base_do_update(struct shash_desc * desc,const u8 * data,unsigned int len,sha256_block_fn * block_fn)38 static inline int sha256_base_do_update(struct shash_desc *desc,
39 const u8 *data,
40 unsigned int len,
41 sha256_block_fn *block_fn)
42 {
43 struct sha256_state *sctx = shash_desc_ctx(desc);
44 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
45
46 sctx->count += len;
47
48 if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
49 int blocks;
50
51 if (partial) {
52 int p = SHA256_BLOCK_SIZE - partial;
53
54 memcpy(sctx->buf + partial, data, p);
55 data += p;
56 len -= p;
57
58 block_fn(sctx, sctx->buf, 1);
59 }
60
61 blocks = len / SHA256_BLOCK_SIZE;
62 len %= SHA256_BLOCK_SIZE;
63
64 if (blocks) {
65 block_fn(sctx, data, blocks);
66 data += blocks * SHA256_BLOCK_SIZE;
67 }
68 partial = 0;
69 }
70 if (len)
71 memcpy(sctx->buf + partial, data, len);
72
73 return 0;
74 }
75
sha256_base_do_finalize(struct shash_desc * desc,sha256_block_fn * block_fn)76 static inline int sha256_base_do_finalize(struct shash_desc *desc,
77 sha256_block_fn *block_fn)
78 {
79 const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
80 struct sha256_state *sctx = shash_desc_ctx(desc);
81 __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
82 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
83
84 sctx->buf[partial++] = 0x80;
85 if (partial > bit_offset) {
86 memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
87 partial = 0;
88
89 block_fn(sctx, sctx->buf, 1);
90 }
91
92 memset(sctx->buf + partial, 0x0, bit_offset - partial);
93 *bits = cpu_to_be64(sctx->count << 3);
94 block_fn(sctx, sctx->buf, 1);
95
96 return 0;
97 }
98
sha256_base_finish(struct shash_desc * desc,u8 * out)99 static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
100 {
101 unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
102 struct sha256_state *sctx = shash_desc_ctx(desc);
103 __be32 *digest = (__be32 *)out;
104 int i;
105
106 for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
107 put_unaligned_be32(sctx->state[i], digest++);
108
109 memzero_explicit(sctx, sizeof(*sctx));
110 return 0;
111 }
112
113 #endif /* _CRYPTO_SHA256_BASE_H */
114