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 
14 void blake2s_compress_generic(struct blake2s_state *state, const u8 *block,
15 			      size_t nblocks, const u32 inc);
16 
17 void blake2s_compress(struct blake2s_state *state, const u8 *block,
18 		      size_t nblocks, const u32 inc);
19 
20 bool blake2s_selftest(void);
21 
22 static inline void blake2s_set_lastblock(struct blake2s_state *state)
23 {
24 	state->f[0] = -1;
25 }
26 
27 typedef void (*blake2s_compress_t)(struct blake2s_state *state,
28 				   const u8 *block, size_t nblocks, u32 inc);
29 
30 /* Helper functions for BLAKE2s shared by the library and shash APIs */
31 
32 static inline void __blake2s_update(struct blake2s_state *state,
33 				    const u8 *in, size_t inlen,
34 				    blake2s_compress_t compress)
35 {
36 	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
37 
38 	if (unlikely(!inlen))
39 		return;
40 	if (inlen > fill) {
41 		memcpy(state->buf + state->buflen, in, fill);
42 		(*compress)(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
43 		state->buflen = 0;
44 		in += fill;
45 		inlen -= fill;
46 	}
47 	if (inlen > BLAKE2S_BLOCK_SIZE) {
48 		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
49 		/* Hash one less (full) block than strictly possible */
50 		(*compress)(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
51 		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
52 		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
53 	}
54 	memcpy(state->buf + state->buflen, in, inlen);
55 	state->buflen += inlen;
56 }
57 
58 static inline void __blake2s_final(struct blake2s_state *state, u8 *out,
59 				   blake2s_compress_t compress)
60 {
61 	blake2s_set_lastblock(state);
62 	memset(state->buf + state->buflen, 0,
63 	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
64 	(*compress)(state, state->buf, 1, state->buflen);
65 	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
66 	memcpy(out, state->h, state->outlen);
67 }
68 
69 /* Helper functions for shash implementations of BLAKE2s */
70 
71 struct blake2s_tfm_ctx {
72 	u8 key[BLAKE2S_KEY_SIZE];
73 	unsigned int keylen;
74 };
75 
76 static inline int crypto_blake2s_setkey(struct crypto_shash *tfm,
77 					const u8 *key, unsigned int keylen)
78 {
79 	struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(tfm);
80 
81 	if (keylen == 0 || keylen > BLAKE2S_KEY_SIZE)
82 		return -EINVAL;
83 
84 	memcpy(tctx->key, key, keylen);
85 	tctx->keylen = keylen;
86 
87 	return 0;
88 }
89 
90 static inline int crypto_blake2s_init(struct shash_desc *desc)
91 {
92 	const struct blake2s_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
93 	struct blake2s_state *state = shash_desc_ctx(desc);
94 	unsigned int outlen = crypto_shash_digestsize(desc->tfm);
95 
96 	__blake2s_init(state, outlen, tctx->key, tctx->keylen);
97 	return 0;
98 }
99 
100 static inline int crypto_blake2s_update(struct shash_desc *desc,
101 					const u8 *in, unsigned int inlen,
102 					blake2s_compress_t compress)
103 {
104 	struct blake2s_state *state = shash_desc_ctx(desc);
105 
106 	__blake2s_update(state, in, inlen, compress);
107 	return 0;
108 }
109 
110 static inline int crypto_blake2s_final(struct shash_desc *desc, u8 *out,
111 				       blake2s_compress_t compress)
112 {
113 	struct blake2s_state *state = shash_desc_ctx(desc);
114 
115 	__blake2s_final(state, out, compress);
116 	return 0;
117 }
118 
119 #endif /* _CRYPTO_INTERNAL_BLAKE2S_H */
120