1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 /*
3  * Helper functions for BLAKE2b implementations.
4  * Keep this in sync with the corresponding BLAKE2s header.
5  */
6 
7 #ifndef _CRYPTO_INTERNAL_BLAKE2B_H
8 #define _CRYPTO_INTERNAL_BLAKE2B_H
9 
10 #include <crypto/blake2b.h>
11 #include <crypto/internal/hash.h>
12 #include <linux/string.h>
13 
14 void blake2b_compress_generic(struct blake2b_state *state,
15 			      const u8 *block, size_t nblocks, u32 inc);
16 
17 static inline void blake2b_set_lastblock(struct blake2b_state *state)
18 {
19 	state->f[0] = -1;
20 }
21 
22 typedef void (*blake2b_compress_t)(struct blake2b_state *state,
23 				   const u8 *block, size_t nblocks, u32 inc);
24 
25 static inline void __blake2b_update(struct blake2b_state *state,
26 				    const u8 *in, size_t inlen,
27 				    blake2b_compress_t compress)
28 {
29 	const size_t fill = BLAKE2B_BLOCK_SIZE - state->buflen;
30 
31 	if (unlikely(!inlen))
32 		return;
33 	if (inlen > fill) {
34 		memcpy(state->buf + state->buflen, in, fill);
35 		(*compress)(state, state->buf, 1, BLAKE2B_BLOCK_SIZE);
36 		state->buflen = 0;
37 		in += fill;
38 		inlen -= fill;
39 	}
40 	if (inlen > BLAKE2B_BLOCK_SIZE) {
41 		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2B_BLOCK_SIZE);
42 		/* Hash one less (full) block than strictly possible */
43 		(*compress)(state, in, nblocks - 1, BLAKE2B_BLOCK_SIZE);
44 		in += BLAKE2B_BLOCK_SIZE * (nblocks - 1);
45 		inlen -= BLAKE2B_BLOCK_SIZE * (nblocks - 1);
46 	}
47 	memcpy(state->buf + state->buflen, in, inlen);
48 	state->buflen += inlen;
49 }
50 
51 static inline void __blake2b_final(struct blake2b_state *state, u8 *out,
52 				   blake2b_compress_t compress)
53 {
54 	int i;
55 
56 	blake2b_set_lastblock(state);
57 	memset(state->buf + state->buflen, 0,
58 	       BLAKE2B_BLOCK_SIZE - state->buflen); /* Padding */
59 	(*compress)(state, state->buf, 1, state->buflen);
60 	for (i = 0; i < ARRAY_SIZE(state->h); i++)
61 		__cpu_to_le64s(&state->h[i]);
62 	memcpy(out, state->h, state->outlen);
63 }
64 
65 /* Helper functions for shash implementations of BLAKE2b */
66 
67 struct blake2b_tfm_ctx {
68 	u8 key[BLAKE2B_KEY_SIZE];
69 	unsigned int keylen;
70 };
71 
72 static inline int crypto_blake2b_setkey(struct crypto_shash *tfm,
73 					const u8 *key, unsigned int keylen)
74 {
75 	struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(tfm);
76 
77 	if (keylen == 0 || keylen > BLAKE2B_KEY_SIZE)
78 		return -EINVAL;
79 
80 	memcpy(tctx->key, key, keylen);
81 	tctx->keylen = keylen;
82 
83 	return 0;
84 }
85 
86 static inline int crypto_blake2b_init(struct shash_desc *desc)
87 {
88 	const struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
89 	struct blake2b_state *state = shash_desc_ctx(desc);
90 	unsigned int outlen = crypto_shash_digestsize(desc->tfm);
91 
92 	__blake2b_init(state, outlen, tctx->key, tctx->keylen);
93 	return 0;
94 }
95 
96 static inline int crypto_blake2b_update(struct shash_desc *desc,
97 					const u8 *in, unsigned int inlen,
98 					blake2b_compress_t compress)
99 {
100 	struct blake2b_state *state = shash_desc_ctx(desc);
101 
102 	__blake2b_update(state, in, inlen, compress);
103 	return 0;
104 }
105 
106 static inline int crypto_blake2b_final(struct shash_desc *desc, u8 *out,
107 				       blake2b_compress_t compress)
108 {
109 	struct blake2b_state *state = shash_desc_ctx(desc);
110 
111 	__blake2b_final(state, out, compress);
112 	return 0;
113 }
114 
115 #endif /* _CRYPTO_INTERNAL_BLAKE2B_H */
116