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1// SPDX-License-Identifier: GPL-2.0 OR MIT
2/*
3 * Copyright (C) 2015-2019 Jason A. Donenfeld <[email protected]>. 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#include "blake2s.h"
11#include <linux/kernel.h>
12
13static inline u32 ror32(u32 v, int n)
14{
15 return (v >> n) | (v << (32 - n));
16}
17
18static inline void le32_to_cpu_array(u32 a[], size_t n)
19{
20 for (size_t i = 0; i < n; i++)
21 a[i] = le32_to_cpu((__force __le32)a[i]);
22}
23
24static inline void cpu_to_le32_array(u32 a[], size_t n)
25{
26 for (size_t i = 0; i < n; i++)
27 a[i] = (__force u32)cpu_to_le32(a[i]);
28}
29
30static const u8 blake2s_sigma[10][16] = {
31 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
32 { 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 },
33 { 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
34 { 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
35 { 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
36 { 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
37 { 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
38 { 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
39 { 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
40 { 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
41};
42
43static inline void blake2s_increment_counter(struct blake2s_ctx *ctx, u32 inc)
44{
45 ctx->t[0] += inc;
46 ctx->t[1] += (ctx->t[0] < inc);
47}
48
49static void blake2s_compress(struct blake2s_ctx *ctx,
50 const u8 *data, size_t nblocks, u32 inc)
51{
52 u32 m[16];
53 u32 v[16];
54 int i;
55
56 while (nblocks > 0) {
57 blake2s_increment_counter(ctx, inc);
58 memcpy(m, data, BLAKE2S_BLOCK_SIZE);
59 le32_to_cpu_array(m, ARRAY_SIZE(m));
60 memcpy(v, ctx->h, 32);
61 v[ 8] = BLAKE2S_IV0;
62 v[ 9] = BLAKE2S_IV1;
63 v[10] = BLAKE2S_IV2;
64 v[11] = BLAKE2S_IV3;
65 v[12] = BLAKE2S_IV4 ^ ctx->t[0];
66 v[13] = BLAKE2S_IV5 ^ ctx->t[1];
67 v[14] = BLAKE2S_IV6 ^ ctx->f[0];
68 v[15] = BLAKE2S_IV7 ^ ctx->f[1];
69
70#define G(r, i, a, b, c, d) do { \
71 a += b + m[blake2s_sigma[r][2 * i + 0]]; \
72 d = ror32(d ^ a, 16); \
73 c += d; \
74 b = ror32(b ^ c, 12); \
75 a += b + m[blake2s_sigma[r][2 * i + 1]]; \
76 d = ror32(d ^ a, 8); \
77 c += d; \
78 b = ror32(b ^ c, 7); \
79} while (0)
80
81#define ROUND(r) do { \
82 G(r, 0, v[0], v[ 4], v[ 8], v[12]); \
83 G(r, 1, v[1], v[ 5], v[ 9], v[13]); \
84 G(r, 2, v[2], v[ 6], v[10], v[14]); \
85 G(r, 3, v[3], v[ 7], v[11], v[15]); \
86 G(r, 4, v[0], v[ 5], v[10], v[15]); \
87 G(r, 5, v[1], v[ 6], v[11], v[12]); \
88 G(r, 6, v[2], v[ 7], v[ 8], v[13]); \
89 G(r, 7, v[3], v[ 4], v[ 9], v[14]); \
90} while (0)
91 ROUND(0);
92 ROUND(1);
93 ROUND(2);
94 ROUND(3);
95 ROUND(4);
96 ROUND(5);
97 ROUND(6);
98 ROUND(7);
99 ROUND(8);
100 ROUND(9);
101
102#undef G
103#undef ROUND
104
105 for (i = 0; i < 8; ++i)
106 ctx->h[i] ^= v[i] ^ v[i + 8];
107
108 data += BLAKE2S_BLOCK_SIZE;
109 --nblocks;
110 }
111}
112
113static inline void blake2s_set_lastblock(struct blake2s_ctx *ctx)
114{
115 ctx->f[0] = -1;
116}
117
118void blake2s_update(struct blake2s_ctx *ctx, const u8 *in, size_t inlen)
119{
120 const size_t fill = BLAKE2S_BLOCK_SIZE - ctx->buflen;
121
122 if (unlikely(!inlen))
123 return;
124 if (inlen > fill) {
125 memcpy(ctx->buf + ctx->buflen, in, fill);
126 blake2s_compress(ctx, ctx->buf, 1, BLAKE2S_BLOCK_SIZE);
127 ctx->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
134 blake2s_compress(ctx, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
135 in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
136 inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
137 }
138 memcpy(ctx->buf + ctx->buflen, in, inlen);
139 ctx->buflen += inlen;
140}
141
142void blake2s_final(struct blake2s_ctx *ctx, u8 *out)
143{
144 blake2s_set_lastblock(ctx);
145 memset(ctx->buf + ctx->buflen, 0,
146 BLAKE2S_BLOCK_SIZE - ctx->buflen); /* Padding */
147 blake2s_compress(ctx, ctx->buf, 1, ctx->buflen);
148 cpu_to_le32_array(ctx->h, ARRAY_SIZE(ctx->h));
149 memcpy(out, ctx->h, ctx->outlen);
150 memset(ctx, 0, sizeof(*ctx));
151}