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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/sha.h>
13#include <linux/crypto.h>
14#include <linux/module.h>
15
16#include <asm/unaligned.h>
17
18typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
19 int blocks);
20
21static inline int sha224_base_init(struct shash_desc *desc)
22{
23 struct sha256_state *sctx = shash_desc_ctx(desc);
24
25 return sha224_init(sctx);
26}
27
28static inline int sha256_base_init(struct shash_desc *desc)
29{
30 struct sha256_state *sctx = shash_desc_ctx(desc);
31
32 return sha256_init(sctx);
33}
34
35static inline int sha256_base_do_update(struct shash_desc *desc,
36 const u8 *data,
37 unsigned int len,
38 sha256_block_fn *block_fn)
39{
40 struct sha256_state *sctx = shash_desc_ctx(desc);
41 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
42
43 sctx->count += len;
44
45 if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
46 int blocks;
47
48 if (partial) {
49 int p = SHA256_BLOCK_SIZE - partial;
50
51 memcpy(sctx->buf + partial, data, p);
52 data += p;
53 len -= p;
54
55 block_fn(sctx, sctx->buf, 1);
56 }
57
58 blocks = len / SHA256_BLOCK_SIZE;
59 len %= SHA256_BLOCK_SIZE;
60
61 if (blocks) {
62 block_fn(sctx, data, blocks);
63 data += blocks * SHA256_BLOCK_SIZE;
64 }
65 partial = 0;
66 }
67 if (len)
68 memcpy(sctx->buf + partial, data, len);
69
70 return 0;
71}
72
73static inline int sha256_base_do_finalize(struct shash_desc *desc,
74 sha256_block_fn *block_fn)
75{
76 const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
77 struct sha256_state *sctx = shash_desc_ctx(desc);
78 __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
79 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
80
81 sctx->buf[partial++] = 0x80;
82 if (partial > bit_offset) {
83 memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
84 partial = 0;
85
86 block_fn(sctx, sctx->buf, 1);
87 }
88
89 memset(sctx->buf + partial, 0x0, bit_offset - partial);
90 *bits = cpu_to_be64(sctx->count << 3);
91 block_fn(sctx, sctx->buf, 1);
92
93 return 0;
94}
95
96static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
97{
98 unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
99 struct sha256_state *sctx = shash_desc_ctx(desc);
100 __be32 *digest = (__be32 *)out;
101 int i;
102
103 for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
104 put_unaligned_be32(sctx->state[i], digest++);
105
106 *sctx = (struct sha256_state){};
107 return 0;
108}
109
110#endif /* _CRYPTO_SHA256_BASE_H */