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
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	sha224_init(sctx);
26	return 0;
27}
28
29static 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
37static 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
74static 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
84static 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
106static 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
114static 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
127static 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