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 <asm/byteorder.h>
11 #include <crypto/blake2b.h>
12 #include <crypto/internal/hash.h>
13 #include <linux/array_size.h>
14 #include <linux/compiler.h>
15 #include <linux/build_bug.h>
16 #include <linux/errno.h>
17 #include <linux/math.h>
18 #include <linux/string.h>
19 #include <linux/types.h>
20 
21 static inline void blake2b_set_lastblock(struct blake2b_state *state)
22 {
23 	state->f[0] = -1;
24 	state->f[1] = 0;
25 }
26 
27 static inline void blake2b_set_nonlast(struct blake2b_state *state)
28 {
29 	state->f[0] = 0;
30 	state->f[1] = 0;
31 }
32 
33 typedef void (*blake2b_compress_t)(struct blake2b_state *state,
34 				   const u8 *block, size_t nblocks, u32 inc);
35 
36 /* Helper functions for shash implementations of BLAKE2b */
37 
38 struct blake2b_tfm_ctx {
39 	u8 key[BLAKE2B_BLOCK_SIZE];
40 	unsigned int keylen;
41 };
42 
43 static inline int crypto_blake2b_setkey(struct crypto_shash *tfm,
44 					const u8 *key, unsigned int keylen)
45 {
46 	struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(tfm);
47 
48 	if (keylen > BLAKE2B_KEY_SIZE)
49 		return -EINVAL;
50 
51 	BUILD_BUG_ON(BLAKE2B_KEY_SIZE > BLAKE2B_BLOCK_SIZE);
52 
53 	memcpy(tctx->key, key, keylen);
54 	memset(tctx->key + keylen, 0, BLAKE2B_BLOCK_SIZE - keylen);
55 	tctx->keylen = keylen;
56 
57 	return 0;
58 }
59 
60 static inline int crypto_blake2b_init(struct shash_desc *desc)
61 {
62 	const struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
63 	struct blake2b_state *state = shash_desc_ctx(desc);
64 	unsigned int outlen = crypto_shash_digestsize(desc->tfm);
65 
66 	__blake2b_init(state, outlen, tctx->keylen);
67 	return tctx->keylen ?
68 	       crypto_shash_update(desc, tctx->key, BLAKE2B_BLOCK_SIZE) : 0;
69 }
70 
71 static inline int crypto_blake2b_update_bo(struct shash_desc *desc,
72 					   const u8 *in, unsigned int inlen,
73 					   blake2b_compress_t compress)
74 {
75 	struct blake2b_state *state = shash_desc_ctx(desc);
76 
77 	blake2b_set_nonlast(state);
78 	compress(state, in, inlen / BLAKE2B_BLOCK_SIZE, BLAKE2B_BLOCK_SIZE);
79 	return inlen - round_down(inlen, BLAKE2B_BLOCK_SIZE);
80 }
81 
82 static inline int crypto_blake2b_finup(struct shash_desc *desc, const u8 *in,
83 				       unsigned int inlen, u8 *out,
84 				       blake2b_compress_t compress)
85 {
86 	struct blake2b_state *state = shash_desc_ctx(desc);
87 	u8 buf[BLAKE2B_BLOCK_SIZE];
88 	int i;
89 
90 	memcpy(buf, in, inlen);
91 	memset(buf + inlen, 0, BLAKE2B_BLOCK_SIZE - inlen);
92 	blake2b_set_lastblock(state);
93 	compress(state, buf, 1, inlen);
94 	for (i = 0; i < ARRAY_SIZE(state->h); i++)
95 		__cpu_to_le64s(&state->h[i]);
96 	memcpy(out, state->h, crypto_shash_digestsize(desc->tfm));
97 	memzero_explicit(buf, sizeof(buf));
98 	return 0;
99 }
100 
101 #endif /* _CRYPTO_INTERNAL_BLAKE2B_H */
102