1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * sha1_base.h - core logic for SHA-1 implementations
4 *
5 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */
7
8#ifndef _CRYPTO_SHA1_BASE_H
9#define _CRYPTO_SHA1_BASE_H
10
11#include <crypto/internal/hash.h>
12#include <crypto/sha1.h>
13#include <linux/crypto.h>
14#include <linux/module.h>
15#include <linux/string.h>
16
17#include <asm/unaligned.h>
18
19typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
20
21static inline int sha1_base_init(struct shash_desc *desc)
22{
23	struct sha1_state *sctx = shash_desc_ctx(desc);
24
25	sctx->state[0] = SHA1_H0;
26	sctx->state[1] = SHA1_H1;
27	sctx->state[2] = SHA1_H2;
28	sctx->state[3] = SHA1_H3;
29	sctx->state[4] = SHA1_H4;
30	sctx->count = 0;
31
32	return 0;
33}
34
35static inline int sha1_base_do_update(struct shash_desc *desc,
36				      const u8 *data,
37				      unsigned int len,
38				      sha1_block_fn *block_fn)
39{
40	struct sha1_state *sctx = shash_desc_ctx(desc);
41	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
42
43	sctx->count += len;
44
45	if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
46		int blocks;
47
48		if (partial) {
49			int p = SHA1_BLOCK_SIZE - partial;
50
51			memcpy(sctx->buffer + partial, data, p);
52			data += p;
53			len -= p;
54
55			block_fn(sctx, sctx->buffer, 1);
56		}
57
58		blocks = len / SHA1_BLOCK_SIZE;
59		len %= SHA1_BLOCK_SIZE;
60
61		if (blocks) {
62			block_fn(sctx, data, blocks);
63			data += blocks * SHA1_BLOCK_SIZE;
64		}
65		partial = 0;
66	}
67	if (len)
68		memcpy(sctx->buffer + partial, data, len);
69
70	return 0;
71}
72
73static inline int sha1_base_do_finalize(struct shash_desc *desc,
74					sha1_block_fn *block_fn)
75{
76	const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
77	struct sha1_state *sctx = shash_desc_ctx(desc);
78	__be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
79	unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
80
81	sctx->buffer[partial++] = 0x80;
82	if (partial > bit_offset) {
83		memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
84		partial = 0;
85
86		block_fn(sctx, sctx->buffer, 1);
87	}
88
89	memset(sctx->buffer + partial, 0x0, bit_offset - partial);
90	*bits = cpu_to_be64(sctx->count << 3);
91	block_fn(sctx, sctx->buffer, 1);
92
93	return 0;
94}
95
96static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
97{
98	struct sha1_state *sctx = shash_desc_ctx(desc);
99	__be32 *digest = (__be32 *)out;
100	int i;
101
102	for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
103		put_unaligned_be32(sctx->state[i], digest++);
104
105	memzero_explicit(sctx, sizeof(*sctx));
106	return 0;
107}
108
109#endif /* _CRYPTO_SHA1_BASE_H */
110