1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * sha512_base.h - core logic for SHA-512 implementations
4 *
5 * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */
7
8#ifndef _CRYPTO_SHA512_BASE_H
9#define _CRYPTO_SHA512_BASE_H
10
11#include <crypto/internal/hash.h>
12#include <crypto/sha2.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 (sha512_block_fn)(struct sha512_state *sst, u8 const *src,
20			       int blocks);
21
22static inline int sha384_base_init(struct shash_desc *desc)
23{
24	struct sha512_state *sctx = shash_desc_ctx(desc);
25
26	sctx->state[0] = SHA384_H0;
27	sctx->state[1] = SHA384_H1;
28	sctx->state[2] = SHA384_H2;
29	sctx->state[3] = SHA384_H3;
30	sctx->state[4] = SHA384_H4;
31	sctx->state[5] = SHA384_H5;
32	sctx->state[6] = SHA384_H6;
33	sctx->state[7] = SHA384_H7;
34	sctx->count[0] = sctx->count[1] = 0;
35
36	return 0;
37}
38
39static inline int sha512_base_init(struct shash_desc *desc)
40{
41	struct sha512_state *sctx = shash_desc_ctx(desc);
42
43	sctx->state[0] = SHA512_H0;
44	sctx->state[1] = SHA512_H1;
45	sctx->state[2] = SHA512_H2;
46	sctx->state[3] = SHA512_H3;
47	sctx->state[4] = SHA512_H4;
48	sctx->state[5] = SHA512_H5;
49	sctx->state[6] = SHA512_H6;
50	sctx->state[7] = SHA512_H7;
51	sctx->count[0] = sctx->count[1] = 0;
52
53	return 0;
54}
55
56static inline int sha512_base_do_update(struct shash_desc *desc,
57					const u8 *data,
58					unsigned int len,
59					sha512_block_fn *block_fn)
60{
61	struct sha512_state *sctx = shash_desc_ctx(desc);
62	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
63
64	sctx->count[0] += len;
65	if (sctx->count[0] < len)
66		sctx->count[1]++;
67
68	if (unlikely((partial + len) >= SHA512_BLOCK_SIZE)) {
69		int blocks;
70
71		if (partial) {
72			int p = SHA512_BLOCK_SIZE - partial;
73
74			memcpy(sctx->buf + partial, data, p);
75			data += p;
76			len -= p;
77
78			block_fn(sctx, sctx->buf, 1);
79		}
80
81		blocks = len / SHA512_BLOCK_SIZE;
82		len %= SHA512_BLOCK_SIZE;
83
84		if (blocks) {
85			block_fn(sctx, data, blocks);
86			data += blocks * SHA512_BLOCK_SIZE;
87		}
88		partial = 0;
89	}
90	if (len)
91		memcpy(sctx->buf + partial, data, len);
92
93	return 0;
94}
95
96static inline int sha512_base_do_finalize(struct shash_desc *desc,
97					  sha512_block_fn *block_fn)
98{
99	const int bit_offset = SHA512_BLOCK_SIZE - sizeof(__be64[2]);
100	struct sha512_state *sctx = shash_desc_ctx(desc);
101	__be64 *bits = (__be64 *)(sctx->buf + bit_offset);
102	unsigned int partial = sctx->count[0] % SHA512_BLOCK_SIZE;
103
104	sctx->buf[partial++] = 0x80;
105	if (partial > bit_offset) {
106		memset(sctx->buf + partial, 0x0, SHA512_BLOCK_SIZE - partial);
107		partial = 0;
108
109		block_fn(sctx, sctx->buf, 1);
110	}
111
112	memset(sctx->buf + partial, 0x0, bit_offset - partial);
113	bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);
114	bits[1] = cpu_to_be64(sctx->count[0] << 3);
115	block_fn(sctx, sctx->buf, 1);
116
117	return 0;
118}
119
120static inline int sha512_base_finish(struct shash_desc *desc, u8 *out)
121{
122	unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
123	struct sha512_state *sctx = shash_desc_ctx(desc);
124	__be64 *digest = (__be64 *)out;
125	int i;
126
127	for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be64))
128		put_unaligned_be64(sctx->state[i], digest++);
129
130	memzero_explicit(sctx, sizeof(*sctx));
131	return 0;
132}
133
134#endif /* _CRYPTO_SHA512_BASE_H */
135