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gerrit-public.fairphone.software / kernel / msm-4.9 / 610081281561d92e4d8bd9c3673d49670396e7ff / . / include / crypto / sha256_base.h
blob: d1f2195bb7def176c33edf99bf11b7698793fa7c [file] [log] [blame]
Ard Biesheuvel11b8d5e2015-04-09 12:55:34 +0200[diff] [blame]1/*
2 * sha256_base.h - core logic for SHA-256 implementations
3 *
4 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
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 sctx->state[0] = SHA224_H0;
26 sctx->state[1] = SHA224_H1;
27 sctx->state[2] = SHA224_H2;
28 sctx->state[3] = SHA224_H3;
29 sctx->state[4] = SHA224_H4;
30 sctx->state[5] = SHA224_H5;
31 sctx->state[6] = SHA224_H6;
32 sctx->state[7] = SHA224_H7;
33 sctx->count = 0;
34
35 return 0;
36}
37
38static inline int sha256_base_init(struct shash_desc *desc)
39{
40 struct sha256_state *sctx = shash_desc_ctx(desc);
41
42 sctx->state[0] = SHA256_H0;
43 sctx->state[1] = SHA256_H1;
44 sctx->state[2] = SHA256_H2;
45 sctx->state[3] = SHA256_H3;
46 sctx->state[4] = SHA256_H4;
47 sctx->state[5] = SHA256_H5;
48 sctx->state[6] = SHA256_H6;
49 sctx->state[7] = SHA256_H7;
50 sctx->count = 0;
51
52 return 0;
53}
54
55static inline int sha256_base_do_update(struct shash_desc *desc,
56 const u8 *data,
57 unsigned int len,
58 sha256_block_fn *block_fn)
59{
60 struct sha256_state *sctx = shash_desc_ctx(desc);
61 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
62
63 sctx->count += len;
64
65 if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
66 int blocks;
67
68 if (partial) {
69 int p = SHA256_BLOCK_SIZE - partial;
70
71 memcpy(sctx->buf + partial, data, p);
72 data += p;
73 len -= p;
74
75 block_fn(sctx, sctx->buf, 1);
76 }
77
78 blocks = len / SHA256_BLOCK_SIZE;
79 len %= SHA256_BLOCK_SIZE;
80
81 if (blocks) {
82 block_fn(sctx, data, blocks);
83 data += blocks * SHA256_BLOCK_SIZE;
84 }
85 partial = 0;
86 }
87 if (len)
88 memcpy(sctx->buf + partial, data, len);
89
90 return 0;
91}
92
93static inline int sha256_base_do_finalize(struct shash_desc *desc,
94 sha256_block_fn *block_fn)
95{
96 const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
97 struct sha256_state *sctx = shash_desc_ctx(desc);
98 __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
99 unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
100
101 sctx->buf[partial++] = 0x80;
102 if (partial > bit_offset) {
103 memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
104 partial = 0;
105
106 block_fn(sctx, sctx->buf, 1);
107 }
108
109 memset(sctx->buf + partial, 0x0, bit_offset - partial);
110 *bits = cpu_to_be64(sctx->count << 3);
111 block_fn(sctx, sctx->buf, 1);
112
113 return 0;
114}
115
116static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
117{
118 unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
119 struct sha256_state *sctx = shash_desc_ctx(desc);
120 __be32 *digest = (__be32 *)out;
121 int i;
122
123 for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
124 put_unaligned_be32(sctx->state[i], digest++);
125
126 *sctx = (struct sha256_state){};
127 return 0;
128}