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