xref: /linux/lib/crypto/blake2s.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
4  *
5  * This is an implementation of the BLAKE2s hash and PRF functions.
6  *
7  * Information: https://blake2.net/
8  *
9  */
10 
11 #include <crypto/blake2s.h>
12 #include <linux/bug.h>
13 #include <linux/export.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 
19 static const u8 blake2s_sigma[10][16] = {
20 	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
21 	{ 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 },
22 	{ 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
23 	{ 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
24 	{ 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
25 	{ 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
26 	{ 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
27 	{ 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
28 	{ 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
29 	{ 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
30 };
31 
32 static inline void blake2s_increment_counter(struct blake2s_state *state,
33 					     const u32 inc)
34 {
35 	state->t[0] += inc;
36 	state->t[1] += (state->t[0] < inc);
37 }
38 
39 static void __maybe_unused
40 blake2s_compress_generic(struct blake2s_state *state, const u8 *block,
41 			 size_t nblocks, const u32 inc)
42 {
43 	u32 m[16];
44 	u32 v[16];
45 	int i;
46 
47 	WARN_ON(IS_ENABLED(DEBUG) &&
48 		(nblocks > 1 && inc != BLAKE2S_BLOCK_SIZE));
49 
50 	while (nblocks > 0) {
51 		blake2s_increment_counter(state, inc);
52 		memcpy(m, block, BLAKE2S_BLOCK_SIZE);
53 		le32_to_cpu_array(m, ARRAY_SIZE(m));
54 		memcpy(v, state->h, 32);
55 		v[ 8] = BLAKE2S_IV0;
56 		v[ 9] = BLAKE2S_IV1;
57 		v[10] = BLAKE2S_IV2;
58 		v[11] = BLAKE2S_IV3;
59 		v[12] = BLAKE2S_IV4 ^ state->t[0];
60 		v[13] = BLAKE2S_IV5 ^ state->t[1];
61 		v[14] = BLAKE2S_IV6 ^ state->f[0];
62 		v[15] = BLAKE2S_IV7 ^ state->f[1];
63 
64 #define G(r, i, a, b, c, d) do { \
65 	a += b + m[blake2s_sigma[r][2 * i + 0]]; \
66 	d = ror32(d ^ a, 16); \
67 	c += d; \
68 	b = ror32(b ^ c, 12); \
69 	a += b + m[blake2s_sigma[r][2 * i + 1]]; \
70 	d = ror32(d ^ a, 8); \
71 	c += d; \
72 	b = ror32(b ^ c, 7); \
73 } while (0)
74 
75 #define ROUND(r) do { \
76 	G(r, 0, v[0], v[ 4], v[ 8], v[12]); \
77 	G(r, 1, v[1], v[ 5], v[ 9], v[13]); \
78 	G(r, 2, v[2], v[ 6], v[10], v[14]); \
79 	G(r, 3, v[3], v[ 7], v[11], v[15]); \
80 	G(r, 4, v[0], v[ 5], v[10], v[15]); \
81 	G(r, 5, v[1], v[ 6], v[11], v[12]); \
82 	G(r, 6, v[2], v[ 7], v[ 8], v[13]); \
83 	G(r, 7, v[3], v[ 4], v[ 9], v[14]); \
84 } while (0)
85 		ROUND(0);
86 		ROUND(1);
87 		ROUND(2);
88 		ROUND(3);
89 		ROUND(4);
90 		ROUND(5);
91 		ROUND(6);
92 		ROUND(7);
93 		ROUND(8);
94 		ROUND(9);
95 
96 #undef G
97 #undef ROUND
98 
99 		for (i = 0; i < 8; ++i)
100 			state->h[i] ^= v[i] ^ v[i + 8];
101 
102 		block += BLAKE2S_BLOCK_SIZE;
103 		--nblocks;
104 	}
105 }
106 
107 #ifdef CONFIG_CRYPTO_LIB_BLAKE2S_ARCH
108 #include "blake2s.h" /* $(SRCARCH)/blake2s.h */
109 #else
110 #define blake2s_compress blake2s_compress_generic
111 #endif
112 
113 static inline void blake2s_set_lastblock(struct blake2s_state *state)
114 {
115 	state->f[0] = -1;
116 }
117 
118 void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen)
119 {
120 	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
121 
122 	if (unlikely(!inlen))
123 		return;
124 	if (inlen > fill) {
125 		memcpy(state->buf + state->buflen, in, fill);
126 		blake2s_compress(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
127 		state->buflen = 0;
128 		in += fill;
129 		inlen -= fill;
130 	}
131 	if (inlen > BLAKE2S_BLOCK_SIZE) {
132 		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
133 		blake2s_compress(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
134 		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
135 		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
136 	}
137 	memcpy(state->buf + state->buflen, in, inlen);
138 	state->buflen += inlen;
139 }
140 EXPORT_SYMBOL(blake2s_update);
141 
142 void blake2s_final(struct blake2s_state *state, u8 *out)
143 {
144 	WARN_ON(IS_ENABLED(DEBUG) && !out);
145 	blake2s_set_lastblock(state);
146 	memset(state->buf + state->buflen, 0,
147 	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
148 	blake2s_compress(state, state->buf, 1, state->buflen);
149 	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
150 	memcpy(out, state->h, state->outlen);
151 	memzero_explicit(state, sizeof(*state));
152 }
153 EXPORT_SYMBOL(blake2s_final);
154 
155 #ifdef blake2s_mod_init_arch
156 static int __init blake2s_mod_init(void)
157 {
158 	blake2s_mod_init_arch();
159 	return 0;
160 }
161 subsys_initcall(blake2s_mod_init);
162 #endif
163 
164 MODULE_DESCRIPTION("BLAKE2s hash function");
165 MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
166