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
|
/* Licensed under GPL v2+ - see LICENSE file for details */
#include <ccan/endian/endian.h>
#include <string.h>
#include "siphash.h"
enum sip_index { A=0, B=2, C=1, D=3, E=4 };
#define rol(x,l) (((x) << (l)) | ((x) >> (64-(l))))
#define SIP_HALF_ROUND(a,b,c,d,L1,L2) \
(a) += (b); \
(c) += (d); \
(b) = (a) ^ rol((b),L1); \
(d) = (c) ^ rol((d),L2); \
(a) = rol((a),32);
#define SIP_ROUND(W) \
do { \
SIP_HALF_ROUND((W)[A], (W)[B], (W)[C], (W)[D], 13, 16); \
SIP_HALF_ROUND((W)[C], (W)[B], (W)[A], (W)[D], 17, 21); \
} while(0)
static inline uint64_t W64(const unsigned char *p, size_t j)
{
uint64_t x;
memcpy(&x, p + j*sizeof(x), sizeof(x));
return le64_to_cpu(x);
}
static void siphash_init(uint64_t v[5], const unsigned char key[16])
{
v[A] = W64(key, 0) ^ UINT64_C(0x736f6d6570736575);
v[B] = W64(key, 1) ^ UINT64_C(0x646f72616e646f6d);
v[C] = W64(key, 0) ^ UINT64_C(0x6c7967656e657261);
v[D] = W64(key, 1) ^ UINT64_C(0x7465646279746573);
v[E] = 0; /* message continuation */
}
/* Load the last 0-7 bytes of `in` and put in len & 255 */
static void siphash_epilogue(uint64_t *m, const unsigned char *in, size_t len)
{
in += len & ~(size_t)7;
*m = (uint64_t)(len & 255) << 56;
switch (len & 7) {
case 7: *m |= (uint64_t) in[6] << 48;
case 6: *m |= (uint64_t) in[5] << 40;
case 5: *m |= (uint64_t) in[4] << 32;
case 4: *m |= (uint64_t) in[3] << 24;
case 3: *m |= (uint64_t) in[2] << 16;
case 2: *m |= (uint64_t) in[1] << 8;
case 1: *m |= (uint64_t) in[0];
case 0: ;
}
}
uint64_t siphash_2_4(const void *in, size_t len, const unsigned char key[16])
{
uint64_t v[5];
size_t j;
siphash_init(v, key);
for (j = 0; j < len/8; j++) {
v[E] = W64(in, j);
v[D] ^= v[E];
SIP_ROUND(v);
SIP_ROUND(v);
v[A] ^= v[E];
}
siphash_epilogue(&v[E], in, len);
v[D] ^= v[E];
SIP_ROUND(v);
SIP_ROUND(v);
v[A] ^= v[E];
/* Finalize */
v[C] ^= 0xff;
SIP_ROUND(v);
SIP_ROUND(v);
SIP_ROUND(v);
SIP_ROUND(v);
return v[A]^v[B]^v[C]^v[D];
}
|
