1/*	$OpenBSD: blake2s.c,v 1.3 2023/02/03 18:31:16 miod Exp $	*/
2/*
3 * Copyright (C) 2012 Samuel Neves <sneves@dei.uc.pt>. All Rights Reserved.
4 * Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 *
18 * This is an implementation of the BLAKE2s hash and PRF functions.
19 * Information: https://blake2.net/
20 */
21
22#include <sys/types.h>
23#include <sys/systm.h>
24
25#include <crypto/blake2s.h>
26
27static inline uint32_t
28ror32(uint32_t word, unsigned int shift)
29{
30	return (word >> shift) | (word << (32 - shift));
31}
32
33static const uint32_t blake2s_iv[8] = {
34	0x6A09E667UL, 0xBB67AE85UL, 0x3C6EF372UL, 0xA54FF53AUL,
35	0x510E527FUL, 0x9B05688CUL, 0x1F83D9ABUL, 0x5BE0CD19UL
36};
37
38static const uint8_t blake2s_sigma[10][16] = {
39	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
40	{ 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 },
41	{ 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
42	{ 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
43	{ 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
44	{ 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
45	{ 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
46	{ 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
47	{ 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
48	{ 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
49};
50
51static inline void blake2s_set_lastblock(struct blake2s_state *state)
52{
53	state->f[0] = -1;
54}
55
56static inline void blake2s_increment_counter(struct blake2s_state *state,
57					     const uint32_t inc)
58{
59	state->t[0] += inc;
60	state->t[1] += (state->t[0] < inc);
61}
62
63static inline void blake2s_init_param(struct blake2s_state *state,
64				      const uint32_t param)
65{
66	int i;
67
68	memset(state, 0, sizeof(*state));
69	for (i = 0; i < 8; ++i)
70		state->h[i] = blake2s_iv[i];
71	state->h[0] ^= param;
72}
73
74void blake2s_init(struct blake2s_state *state, const size_t outlen)
75{
76	KASSERT(!(!outlen || outlen > BLAKE2S_HASH_SIZE));
77	blake2s_init_param(state, 0x01010000 | outlen);
78	state->outlen = outlen;
79}
80
81void blake2s_init_key(struct blake2s_state *state, const size_t outlen,
82		      const void *key, const size_t keylen)
83{
84	uint8_t block[BLAKE2S_BLOCK_SIZE] = { 0 };
85
86	KASSERT(!(!outlen || outlen > BLAKE2S_HASH_SIZE ||
87		  !key || !keylen || keylen > BLAKE2S_KEY_SIZE));
88
89	blake2s_init_param(state, 0x01010000 | keylen << 8 | outlen);
90	state->outlen = outlen;
91	memcpy(block, key, keylen);
92	blake2s_update(state, block, BLAKE2S_BLOCK_SIZE);
93	explicit_bzero(block, BLAKE2S_BLOCK_SIZE);
94}
95
96static inline void blake2s_compress(struct blake2s_state *state,
97				    const uint8_t *block, size_t nblocks,
98				    const uint32_t inc)
99{
100	uint32_t m[16];
101	uint32_t v[16];
102	int i;
103
104	KASSERT(!((nblocks > 1 && inc != BLAKE2S_BLOCK_SIZE)));
105
106	while (nblocks > 0) {
107		blake2s_increment_counter(state, inc);
108		memcpy(m, block, BLAKE2S_BLOCK_SIZE);
109		for (i = 0; i < 16; i++)
110			m[i] = le32toh(m[i]);
111		memcpy(v, state->h, 32);
112		v[ 8] = blake2s_iv[0];
113		v[ 9] = blake2s_iv[1];
114		v[10] = blake2s_iv[2];
115		v[11] = blake2s_iv[3];
116		v[12] = blake2s_iv[4] ^ state->t[0];
117		v[13] = blake2s_iv[5] ^ state->t[1];
118		v[14] = blake2s_iv[6] ^ state->f[0];
119		v[15] = blake2s_iv[7] ^ state->f[1];
120
121#define G(r, i, a, b, c, d) do { \
122	a += b + m[blake2s_sigma[r][2 * i + 0]]; \
123	d = ror32(d ^ a, 16); \
124	c += d; \
125	b = ror32(b ^ c, 12); \
126	a += b + m[blake2s_sigma[r][2 * i + 1]]; \
127	d = ror32(d ^ a, 8); \
128	c += d; \
129	b = ror32(b ^ c, 7); \
130} while (0)
131
132#define ROUND(r) do { \
133	G(r, 0, v[0], v[ 4], v[ 8], v[12]); \
134	G(r, 1, v[1], v[ 5], v[ 9], v[13]); \
135	G(r, 2, v[2], v[ 6], v[10], v[14]); \
136	G(r, 3, v[3], v[ 7], v[11], v[15]); \
137	G(r, 4, v[0], v[ 5], v[10], v[15]); \
138	G(r, 5, v[1], v[ 6], v[11], v[12]); \
139	G(r, 6, v[2], v[ 7], v[ 8], v[13]); \
140	G(r, 7, v[3], v[ 4], v[ 9], v[14]); \
141} while (0)
142		ROUND(0);
143		ROUND(1);
144		ROUND(2);
145		ROUND(3);
146		ROUND(4);
147		ROUND(5);
148		ROUND(6);
149		ROUND(7);
150		ROUND(8);
151		ROUND(9);
152
153#undef G
154#undef ROUND
155
156		for (i = 0; i < 8; ++i)
157			state->h[i] ^= v[i] ^ v[i + 8];
158
159		block += BLAKE2S_BLOCK_SIZE;
160		--nblocks;
161	}
162}
163
164void blake2s_update(struct blake2s_state *state, const uint8_t *in, size_t inlen)
165{
166	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
167
168	if (!inlen)
169		return;
170	if (inlen > fill) {
171		memcpy(state->buf + state->buflen, in, fill);
172		blake2s_compress(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
173		state->buflen = 0;
174		in += fill;
175		inlen -= fill;
176	}
177	if (inlen > BLAKE2S_BLOCK_SIZE) {
178		const size_t nblocks =
179			(inlen + BLAKE2S_BLOCK_SIZE - 1) / BLAKE2S_BLOCK_SIZE;
180		/* Hash one less (full) block than strictly possible */
181		blake2s_compress(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
182		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
183		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
184	}
185	memcpy(state->buf + state->buflen, in, inlen);
186	state->buflen += inlen;
187}
188
189void blake2s_final(struct blake2s_state *state, uint8_t *out)
190{
191	int i;
192	blake2s_set_lastblock(state);
193	memset(state->buf + state->buflen, 0,
194	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
195	blake2s_compress(state, state->buf, 1, state->buflen);
196	for (i = 0; i < 8; i++)
197		state->h[i] = htole32(state->h[i]);
198	memcpy(out, state->h, state->outlen);
199	explicit_bzero(state, sizeof(*state));
200}
201
202void blake2s_hmac(uint8_t *out, const uint8_t *in, const uint8_t *key, const size_t outlen,
203		  const size_t inlen, const size_t keylen)
204{
205	struct blake2s_state state;
206	uint8_t x_key[BLAKE2S_BLOCK_SIZE] __aligned(__alignof__(uint32_t)) = { 0 };
207	uint8_t i_hash[BLAKE2S_HASH_SIZE] __aligned(__alignof__(uint32_t));
208	int i;
209
210	if (keylen > BLAKE2S_BLOCK_SIZE) {
211		blake2s_init(&state, BLAKE2S_HASH_SIZE);
212		blake2s_update(&state, key, keylen);
213		blake2s_final(&state, x_key);
214	} else
215		memcpy(x_key, key, keylen);
216
217	for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
218		x_key[i] ^= 0x36;
219
220	blake2s_init(&state, BLAKE2S_HASH_SIZE);
221	blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
222	blake2s_update(&state, in, inlen);
223	blake2s_final(&state, i_hash);
224
225	for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
226		x_key[i] ^= 0x5c ^ 0x36;
227
228	blake2s_init(&state, BLAKE2S_HASH_SIZE);
229	blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
230	blake2s_update(&state, i_hash, BLAKE2S_HASH_SIZE);
231	blake2s_final(&state, i_hash);
232
233	memcpy(out, i_hash, outlen);
234	explicit_bzero(x_key, BLAKE2S_BLOCK_SIZE);
235	explicit_bzero(i_hash, BLAKE2S_HASH_SIZE);
236}
237