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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/unroll.h>
18#include <linux/types.h>
19
20static const u8 blake2s_sigma[10][16] = {
21 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
22 { 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 },
23 { 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
24 { 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
25 { 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
26 { 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
27 { 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
28 { 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
29 { 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
30 { 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
31};
32
33static inline void blake2s_increment_counter(struct blake2s_ctx *ctx, u32 inc)
34{
35 ctx->t[0] += inc;
36 ctx->t[1] += (ctx->t[0] < inc);
37}
38
39static void __maybe_unused
40blake2s_compress_generic(struct blake2s_ctx *ctx,
41 const u8 *data, size_t nblocks, 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(ctx, inc);
52 memcpy(m, data, BLAKE2S_BLOCK_SIZE);
53 le32_to_cpu_array(m, ARRAY_SIZE(m));
54 memcpy(v, ctx->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 ^ ctx->t[0];
60 v[13] = BLAKE2S_IV5 ^ ctx->t[1];
61 v[14] = BLAKE2S_IV6 ^ ctx->f[0];
62 v[15] = BLAKE2S_IV7 ^ ctx->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 /*
76 * Unroll the rounds loop to enable constant-folding of the
77 * blake2s_sigma values.
78 */
79 unrolled_full
80 for (int r = 0; r < 10; r++) {
81 G(r, 0, v[0], v[4], v[8], v[12]);
82 G(r, 1, v[1], v[5], v[9], v[13]);
83 G(r, 2, v[2], v[6], v[10], v[14]);
84 G(r, 3, v[3], v[7], v[11], v[15]);
85 G(r, 4, v[0], v[5], v[10], v[15]);
86 G(r, 5, v[1], v[6], v[11], v[12]);
87 G(r, 6, v[2], v[7], v[8], v[13]);
88 G(r, 7, v[3], v[4], v[9], v[14]);
89 }
90#undef G
91
92 for (i = 0; i < 8; ++i)
93 ctx->h[i] ^= v[i] ^ v[i + 8];
94
95 data += BLAKE2S_BLOCK_SIZE;
96 --nblocks;
97 }
98}
99
100#ifdef CONFIG_CRYPTO_LIB_BLAKE2S_ARCH
101#include "blake2s.h" /* $(SRCARCH)/blake2s.h */
102#else
103#define blake2s_compress blake2s_compress_generic
104#endif
105
106static inline void blake2s_set_lastblock(struct blake2s_ctx *ctx)
107{
108 ctx->f[0] = -1;
109}
110
111void blake2s_update(struct blake2s_ctx *ctx, const u8 *in, size_t inlen)
112{
113 const size_t fill = BLAKE2S_BLOCK_SIZE - ctx->buflen;
114
115 if (unlikely(!inlen))
116 return;
117 if (inlen > fill) {
118 memcpy(ctx->buf + ctx->buflen, in, fill);
119 blake2s_compress(ctx, ctx->buf, 1, BLAKE2S_BLOCK_SIZE);
120 ctx->buflen = 0;
121 in += fill;
122 inlen -= fill;
123 }
124 if (inlen > BLAKE2S_BLOCK_SIZE) {
125 const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
126
127 blake2s_compress(ctx, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
128 in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
129 inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
130 }
131 memcpy(ctx->buf + ctx->buflen, in, inlen);
132 ctx->buflen += inlen;
133}
134EXPORT_SYMBOL(blake2s_update);
135
136void blake2s_final(struct blake2s_ctx *ctx, u8 *out)
137{
138 WARN_ON(IS_ENABLED(DEBUG) && !out);
139 blake2s_set_lastblock(ctx);
140 memset(ctx->buf + ctx->buflen, 0,
141 BLAKE2S_BLOCK_SIZE - ctx->buflen); /* Padding */
142 blake2s_compress(ctx, ctx->buf, 1, ctx->buflen);
143 cpu_to_le32_array(ctx->h, ARRAY_SIZE(ctx->h));
144 memcpy(out, ctx->h, ctx->outlen);
145 memzero_explicit(ctx, sizeof(*ctx));
146}
147EXPORT_SYMBOL(blake2s_final);
148
149#ifdef blake2s_mod_init_arch
150static int __init blake2s_mod_init(void)
151{
152 blake2s_mod_init_arch();
153 return 0;
154}
155subsys_initcall(blake2s_mod_init);
156#endif
157
158MODULE_DESCRIPTION("BLAKE2s hash function");
159MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");