1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
* Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* Implementation of the ChaCha20 stream cipher.
*
* Information: https://cr.yp.to/chacha.html
*/
#include <zinc/chacha20.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <crypto/algapi.h>
#if defined(CONFIG_ZINC_ARCH_X86_64)
#include "chacha20-x86_64-glue.h"
#elif defined(CONFIG_ZINC_ARCH_ARM) || defined(CONFIG_ZINC_ARCH_ARM64)
#include "chacha20-arm-glue.h"
#elif defined(CONFIG_ZINC_ARCH_MIPS)
#include "chacha20-mips-glue.h"
#else
void __init chacha20_fpu_init(void)
{
}
static inline bool chacha20_arch(struct chacha20_ctx *state, u8 *dst,
const u8 *src, size_t len,
simd_context_t *simd_context)
{
return false;
}
static inline bool hchacha20_arch(u32 derived_key[CHACHA20_KEY_WORDS],
const u8 nonce[HCHACHA20_NONCE_SIZE],
const u8 key[HCHACHA20_KEY_SIZE],
simd_context_t *simd_context)
{
return false;
}
#endif
#define QUARTER_ROUND(x, a, b, c, d) ( \
x[a] += x[b], \
x[d] = rol32((x[d] ^ x[a]), 16), \
x[c] += x[d], \
x[b] = rol32((x[b] ^ x[c]), 12), \
x[a] += x[b], \
x[d] = rol32((x[d] ^ x[a]), 8), \
x[c] += x[d], \
x[b] = rol32((x[b] ^ x[c]), 7) \
)
#define C(i, j) (i * 4 + j)
#define DOUBLE_ROUND(x) ( \
/* Column Round */ \
QUARTER_ROUND(x, C(0, 0), C(1, 0), C(2, 0), C(3, 0)), \
QUARTER_ROUND(x, C(0, 1), C(1, 1), C(2, 1), C(3, 1)), \
QUARTER_ROUND(x, C(0, 2), C(1, 2), C(2, 2), C(3, 2)), \
QUARTER_ROUND(x, C(0, 3), C(1, 3), C(2, 3), C(3, 3)), \
/* Diagonal Round */ \
QUARTER_ROUND(x, C(0, 0), C(1, 1), C(2, 2), C(3, 3)), \
QUARTER_ROUND(x, C(0, 1), C(1, 2), C(2, 3), C(3, 0)), \
QUARTER_ROUND(x, C(0, 2), C(1, 3), C(2, 0), C(3, 1)), \
QUARTER_ROUND(x, C(0, 3), C(1, 0), C(2, 1), C(3, 2)) \
)
#define TWENTY_ROUNDS(x) ( \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x), \
DOUBLE_ROUND(x) \
)
static void chacha20_block_generic(__le32 *stream, u32 *state)
{
u32 x[CHACHA20_BLOCK_WORDS];
int i;
for (i = 0; i < ARRAY_SIZE(x); ++i)
x[i] = state[i];
TWENTY_ROUNDS(x);
for (i = 0; i < ARRAY_SIZE(x); ++i)
stream[i] = cpu_to_le32(x[i] + state[i]);
++state[12];
}
static void chacha20_generic(struct chacha20_ctx *state, u8 *out, const u8 *in,
u32 len)
{
__le32 buf[CHACHA20_BLOCK_WORDS];
while (len >= CHACHA20_BLOCK_SIZE) {
chacha20_block_generic(buf, (u32 *)state);
crypto_xor_cpy(out, in, (u8 *)buf, CHACHA20_BLOCK_SIZE);
len -= CHACHA20_BLOCK_SIZE;
out += CHACHA20_BLOCK_SIZE;
in += CHACHA20_BLOCK_SIZE;
}
if (len) {
chacha20_block_generic(buf, (u32 *)state);
crypto_xor_cpy(out, in, (u8 *)buf, len);
}
}
void chacha20(struct chacha20_ctx *state, u8 *dst, const u8 *src, u32 len,
simd_context_t *simd_context)
{
if (!chacha20_arch(state, dst, src, len, simd_context))
chacha20_generic(state, dst, src, len);
}
EXPORT_SYMBOL(chacha20);
static void hchacha20_generic(u32 derived_key[CHACHA20_KEY_WORDS],
const u8 nonce[HCHACHA20_NONCE_SIZE],
const u8 key[HCHACHA20_KEY_SIZE])
{
u32 x[] = { CHACHA20_CONSTANT_EXPA,
CHACHA20_CONSTANT_ND_3,
CHACHA20_CONSTANT_2_BY,
CHACHA20_CONSTANT_TE_K,
get_unaligned_le32(key + 0),
get_unaligned_le32(key + 4),
get_unaligned_le32(key + 8),
get_unaligned_le32(key + 12),
get_unaligned_le32(key + 16),
get_unaligned_le32(key + 20),
get_unaligned_le32(key + 24),
get_unaligned_le32(key + 28),
get_unaligned_le32(nonce + 0),
get_unaligned_le32(nonce + 4),
get_unaligned_le32(nonce + 8),
get_unaligned_le32(nonce + 12)
};
TWENTY_ROUNDS(x);
memcpy(derived_key + 0, x + 0, sizeof(u32) * 4);
memcpy(derived_key + 4, x + 12, sizeof(u32) * 4);
}
/* Derived key should be 32-bit aligned */
void hchacha20(u32 derived_key[CHACHA20_KEY_WORDS],
const u8 nonce[HCHACHA20_NONCE_SIZE],
const u8 key[HCHACHA20_KEY_SIZE], simd_context_t *simd_context)
{
if (!hchacha20_arch(derived_key, nonce, key, simd_context))
hchacha20_generic(derived_key, nonce, key);
}
EXPORT_SYMBOL(hchacha20);
#include "../selftest/chacha20.h"
static bool nosimd __initdata = false;
#ifndef COMPAT_ZINC_IS_A_MODULE
int __init chacha20_mod_init(void)
#else
static int __init mod_init(void)
#endif
{
if (!nosimd)
chacha20_fpu_init();
#ifdef CONFIG_ZINC_SELFTEST
if (!chacha20_selftest())
return -ENOTRECOVERABLE;
#endif
return 0;
}
#ifdef COMPAT_ZINC_IS_A_MODULE
static void __exit mod_exit(void)
{
}
module_param(nosimd, bool, 0);
module_init(mod_init);
module_exit(mod_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ChaCha20 stream cipher");
MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
#endif
|
