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 * Copyright 2025 Google LLC
5 *
6 * This is an implementation of the BLAKE2b hash and PRF functions.
7 *
8 * Information: https://blake2.net/
9 */
10
11 #include <crypto/blake2b.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 blake2b_sigma[12][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 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
31 { 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 }
32 };
33
blake2b_increment_counter(struct blake2b_ctx * ctx,u32 inc)34 static inline void blake2b_increment_counter(struct blake2b_ctx *ctx, u32 inc)
35 {
36 ctx->t[0] += inc;
37 ctx->t[1] += (ctx->t[0] < inc);
38 }
39
40 static void __maybe_unused
blake2b_compress_generic(struct blake2b_ctx * ctx,const u8 * data,size_t nblocks,u32 inc)41 blake2b_compress_generic(struct blake2b_ctx *ctx,
42 const u8 *data, size_t nblocks, u32 inc)
43 {
44 u64 m[16];
45 u64 v[16];
46 int i;
47
48 WARN_ON(IS_ENABLED(DEBUG) &&
49 (nblocks > 1 && inc != BLAKE2B_BLOCK_SIZE));
50
51 while (nblocks > 0) {
52 blake2b_increment_counter(ctx, inc);
53 memcpy(m, data, BLAKE2B_BLOCK_SIZE);
54 le64_to_cpu_array(m, ARRAY_SIZE(m));
55 memcpy(v, ctx->h, 64);
56 v[ 8] = BLAKE2B_IV0;
57 v[ 9] = BLAKE2B_IV1;
58 v[10] = BLAKE2B_IV2;
59 v[11] = BLAKE2B_IV3;
60 v[12] = BLAKE2B_IV4 ^ ctx->t[0];
61 v[13] = BLAKE2B_IV5 ^ ctx->t[1];
62 v[14] = BLAKE2B_IV6 ^ ctx->f[0];
63 v[15] = BLAKE2B_IV7 ^ ctx->f[1];
64
65 #define G(r, i, a, b, c, d) do { \
66 a += b + m[blake2b_sigma[r][2 * i + 0]]; \
67 d = ror64(d ^ a, 32); \
68 c += d; \
69 b = ror64(b ^ c, 24); \
70 a += b + m[blake2b_sigma[r][2 * i + 1]]; \
71 d = ror64(d ^ a, 16); \
72 c += d; \
73 b = ror64(b ^ c, 63); \
74 } while (0)
75
76 #define ROUND(r) do { \
77 G(r, 0, v[0], v[ 4], v[ 8], v[12]); \
78 G(r, 1, v[1], v[ 5], v[ 9], v[13]); \
79 G(r, 2, v[2], v[ 6], v[10], v[14]); \
80 G(r, 3, v[3], v[ 7], v[11], v[15]); \
81 G(r, 4, v[0], v[ 5], v[10], v[15]); \
82 G(r, 5, v[1], v[ 6], v[11], v[12]); \
83 G(r, 6, v[2], v[ 7], v[ 8], v[13]); \
84 G(r, 7, v[3], v[ 4], v[ 9], v[14]); \
85 } while (0)
86 ROUND(0);
87 ROUND(1);
88 ROUND(2);
89 ROUND(3);
90 ROUND(4);
91 ROUND(5);
92 ROUND(6);
93 ROUND(7);
94 ROUND(8);
95 ROUND(9);
96 ROUND(10);
97 ROUND(11);
98
99 #undef G
100 #undef ROUND
101
102 for (i = 0; i < 8; ++i)
103 ctx->h[i] ^= v[i] ^ v[i + 8];
104
105 data += BLAKE2B_BLOCK_SIZE;
106 --nblocks;
107 }
108 }
109
110 #ifdef CONFIG_CRYPTO_LIB_BLAKE2B_ARCH
111 #include "blake2b.h" /* $(SRCARCH)/blake2b.h */
112 #else
113 #define blake2b_compress blake2b_compress_generic
114 #endif
115
blake2b_set_lastblock(struct blake2b_ctx * ctx)116 static inline void blake2b_set_lastblock(struct blake2b_ctx *ctx)
117 {
118 ctx->f[0] = -1;
119 }
120
blake2b_update(struct blake2b_ctx * ctx,const u8 * in,size_t inlen)121 void blake2b_update(struct blake2b_ctx *ctx, const u8 *in, size_t inlen)
122 {
123 const size_t fill = BLAKE2B_BLOCK_SIZE - ctx->buflen;
124
125 if (unlikely(!inlen))
126 return;
127 if (inlen > fill) {
128 memcpy(ctx->buf + ctx->buflen, in, fill);
129 blake2b_compress(ctx, ctx->buf, 1, BLAKE2B_BLOCK_SIZE);
130 ctx->buflen = 0;
131 in += fill;
132 inlen -= fill;
133 }
134 if (inlen > BLAKE2B_BLOCK_SIZE) {
135 const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2B_BLOCK_SIZE);
136
137 blake2b_compress(ctx, in, nblocks - 1, BLAKE2B_BLOCK_SIZE);
138 in += BLAKE2B_BLOCK_SIZE * (nblocks - 1);
139 inlen -= BLAKE2B_BLOCK_SIZE * (nblocks - 1);
140 }
141 memcpy(ctx->buf + ctx->buflen, in, inlen);
142 ctx->buflen += inlen;
143 }
144 EXPORT_SYMBOL(blake2b_update);
145
blake2b_final(struct blake2b_ctx * ctx,u8 * out)146 void blake2b_final(struct blake2b_ctx *ctx, u8 *out)
147 {
148 WARN_ON(IS_ENABLED(DEBUG) && !out);
149 blake2b_set_lastblock(ctx);
150 memset(ctx->buf + ctx->buflen, 0,
151 BLAKE2B_BLOCK_SIZE - ctx->buflen); /* Padding */
152 blake2b_compress(ctx, ctx->buf, 1, ctx->buflen);
153 cpu_to_le64_array(ctx->h, ARRAY_SIZE(ctx->h));
154 memcpy(out, ctx->h, ctx->outlen);
155 memzero_explicit(ctx, sizeof(*ctx));
156 }
157 EXPORT_SYMBOL(blake2b_final);
158
159 #ifdef blake2b_mod_init_arch
blake2b_mod_init(void)160 static int __init blake2b_mod_init(void)
161 {
162 blake2b_mod_init_arch();
163 return 0;
164 }
165 subsys_initcall(blake2b_mod_init);
166
blake2b_mod_exit(void)167 static void __exit blake2b_mod_exit(void)
168 {
169 }
170 module_exit(blake2b_mod_exit);
171 #endif
172
173 MODULE_DESCRIPTION("BLAKE2b hash function");
174 MODULE_LICENSE("GPL");
175