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
|
/*
* Based on public domain code available at: http://cr.yp.to/snuffle.html
*
* This therefore is public domain.
*/
#ifndef ZT_SALSA20_HPP
#define ZT_SALSA20_HPP
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "Constants.hpp"
#include "Utils.hpp"
#if (!defined(ZT_SALSA20_SSE)) && (defined(__SSE2__) || defined(__WINDOWS__))
#define ZT_SALSA20_SSE 1
#endif
#ifdef ZT_SALSA20_SSE
#include <emmintrin.h>
#endif // ZT_SALSA20_SSE
namespace ZeroTier {
/**
* Salsa20 stream cipher
*/
class Salsa20
{
public:
Salsa20() {}
~Salsa20() { Utils::burn(&_state,sizeof(_state)); }
/**
* XOR d with s
*
* This is done efficiently using e.g. SSE if available. It's used when
* alternative Salsa20 implementations are used in Packet and is here
* since this is where all the SSE stuff is already included.
*
* @param d Destination to XOR
* @param s Source bytes to XOR with destination
* @param len Length of s and d
*/
static inline void memxor(uint8_t *d,const uint8_t *s,unsigned int len)
{
#ifdef ZT_SALSA20_SSE
while (len >= 16) {
_mm_storeu_si128(reinterpret_cast<__m128i *>(d),_mm_xor_si128(_mm_loadu_si128(reinterpret_cast<__m128i *>(d)),_mm_loadu_si128(reinterpret_cast<const __m128i *>(s))));
s += 16;
d += 16;
len -= 16;
}
#else
#ifndef ZT_NO_TYPE_PUNNING
while (len >= 16) {
(*reinterpret_cast<uint64_t *>(d)) ^= (*reinterpret_cast<const uint64_t *>(s));
s += 8;
d += 8;
(*reinterpret_cast<uint64_t *>(d)) ^= (*reinterpret_cast<const uint64_t *>(s));
s += 8;
d += 8;
len -= 16;
}
#endif
#endif
while (len--)
*(d++) ^= *(s++);
}
/**
* @param key 256-bit (32 byte) key
* @param iv 64-bit initialization vector
*/
Salsa20(const void *key,const void *iv)
{
init(key,iv);
}
/**
* Initialize cipher
*
* @param key Key bits
* @param iv 64-bit initialization vector
*/
void init(const void *key,const void *iv);
/**
* Encrypt/decrypt data using Salsa20/12
*
* @param in Input data
* @param out Output buffer
* @param bytes Length of data
*/
void crypt12(const void *in,void *out,unsigned int bytes);
/**
* Encrypt/decrypt data using Salsa20/20
*
* @param in Input data
* @param out Output buffer
* @param bytes Length of data
*/
void crypt20(const void *in,void *out,unsigned int bytes);
private:
union {
#ifdef ZT_SALSA20_SSE
__m128i v[4];
#endif // ZT_SALSA20_SSE
uint32_t i[16];
} _state;
};
} // namespace ZeroTier
#endif
|
