1/* SPDX-License-Identifier: GPL-2.0 OR MIT */
2/*
3 * Helper functions for BLAKE2s implementations.
4 * Keep this in sync with the corresponding BLAKE2b header.
5 */
6
7#ifndef _CRYPTO_INTERNAL_BLAKE2S_H
8#define _CRYPTO_INTERNAL_BLAKE2S_H
9
10#include <crypto/blake2s.h>
11#include <crypto/internal/hash.h>
12#include <linux/string.h>
13
14void blake2s_compress_generic(struct blake2s_state *state, const u8 *block,
15			      size_t nblocks, const u32 inc);
16
17void blake2s_compress(struct blake2s_state *state, const u8 *block,
18		      size_t nblocks, const u32 inc);
19
20bool blake2s_selftest(void);
21
22static inline void blake2s_set_lastblock(struct blake2s_state *state)
23{
24	state->f[0] = -1;
25}
26
27/* Helper functions for BLAKE2s shared by the library and shash APIs */
28
29static __always_inline void
30__blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen,
31		 bool force_generic)
32{
33	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
34
35	if (unlikely(!inlen))
36		return;
37	if (inlen > fill) {
38		memcpy(state->buf + state->buflen, in, fill);
39		if (force_generic)
40			blake2s_compress_generic(state, state->buf, 1,
41						 BLAKE2S_BLOCK_SIZE);
42		else
43			blake2s_compress(state, state->buf, 1,
44					 BLAKE2S_BLOCK_SIZE);
45		state->buflen = 0;
46		in += fill;
47		inlen -= fill;
48	}
49	if (inlen > BLAKE2S_BLOCK_SIZE) {
50		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
51		/* Hash one less (full) block than strictly possible */
52		if (force_generic)
53			blake2s_compress_generic(state, in, nblocks - 1,
54						 BLAKE2S_BLOCK_SIZE);
55		else
56			blake2s_compress(state, in, nblocks - 1,
57					 BLAKE2S_BLOCK_SIZE);
58		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
59		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
60	}
61	memcpy(state->buf + state->buflen, in, inlen);
62	state->buflen += inlen;
63}
64
65static __always_inline void
66__blake2s_final(struct blake2s_state *state, u8 *out, bool force_generic)
67{
68	blake2s_set_lastblock(state);
69	memset(state->buf + state->buflen, 0,
70	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
71	if (force_generic)
72		blake2s_compress_generic(state, state->buf, 1, state->buflen);
73	else
74		blake2s_compress(state, state->buf, 1, state->buflen);
75	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
76	memcpy(out, state->h, state->outlen);
77}
78
79/* Helper functions for shash implementations of BLAKE2s */
80
81struct blake2s_tfm_ctx {
82	u8 key[BLAKE2S_KEY_SIZE];
83	unsigned int keylen;
84};
85
86static inline int crypto_blake2s_setkey(struct crypto_shash *tfm,
87					const u8 *key, unsigned int keylen)
88{
89	struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(tfm);
90
91	if (keylen == 0 || keylen > BLAKE2S_KEY_SIZE)
92		return -EINVAL;
93
94	memcpy(tctx->key, key, keylen);
95	tctx->keylen = keylen;
96
97	return 0;
98}
99
100static inline int crypto_blake2s_init(struct shash_desc *desc)
101{
102	const struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
103	struct blake2s_state *state = shash_desc_ctx(desc);
104	unsigned int outlen = crypto_shash_digestsize(desc->tfm);
105
106	__blake2s_init(state, outlen, tctx->key, tctx->keylen);
107	return 0;
108}
109
110static inline int crypto_blake2s_update(struct shash_desc *desc,
111					const u8 *in, unsigned int inlen,
112					bool force_generic)
113{
114	struct blake2s_state *state = shash_desc_ctx(desc);
115
116	__blake2s_update(state, in, inlen, force_generic);
117	return 0;
118}
119
120static inline int crypto_blake2s_final(struct shash_desc *desc, u8 *out,
121				       bool force_generic)
122{
123	struct blake2s_state *state = shash_desc_ctx(desc);
124
125	__blake2s_final(state, out, force_generic);
126	return 0;
127}
128
129#endif /* _CRYPTO_INTERNAL_BLAKE2S_H */
130