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
193
194
195
196
197
198
199
200
201
202
|
/* SPDX-License-Identifier: CC0-1.0 */
/*
SipHash reference C implementation
Written in 2012 by
Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Daniel J. Bernstein <djb@cr.yp.to>
To the extent possible under law, the author(s) have dedicated all copyright
and related and neighboring rights to this software to the public domain
worldwide. This software is distributed without any warranty.
You should have received a copy of the CC0 Public Domain Dedication along with
this software. If not, see <https://creativecommons.org/publicdomain/zero/1.0/>.
(Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd)
(Refactored by Tom Gundersen to split up in several functions and follow systemd
coding style)
*/
#include <stdio.h>
#include "macro.h"
#include "siphash24.h"
#include "unaligned.h"
static uint64_t rotate_left(uint64_t x, uint8_t b) {
assert(b < 64);
return (x << b) | (x >> (64 - b));
}
static void sipround(struct siphash *state) {
assert(state);
state->v0 += state->v1;
state->v1 = rotate_left(state->v1, 13);
state->v1 ^= state->v0;
state->v0 = rotate_left(state->v0, 32);
state->v2 += state->v3;
state->v3 = rotate_left(state->v3, 16);
state->v3 ^= state->v2;
state->v0 += state->v3;
state->v3 = rotate_left(state->v3, 21);
state->v3 ^= state->v0;
state->v2 += state->v1;
state->v1 = rotate_left(state->v1, 17);
state->v1 ^= state->v2;
state->v2 = rotate_left(state->v2, 32);
}
void siphash24_init(struct siphash *state, const uint8_t k[static 16]) {
uint64_t k0, k1;
assert(state);
assert(k);
k0 = unaligned_read_le64(k);
k1 = unaligned_read_le64(k + 8);
*state = (struct siphash) {
/* "somepseudorandomlygeneratedbytes" */
.v0 = 0x736f6d6570736575ULL ^ k0,
.v1 = 0x646f72616e646f6dULL ^ k1,
.v2 = 0x6c7967656e657261ULL ^ k0,
.v3 = 0x7465646279746573ULL ^ k1,
.padding = 0,
.inlen = 0,
};
}
void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
const uint8_t *in = _in;
const uint8_t *end = in + inlen;
size_t left = state->inlen & 7;
uint64_t m;
assert(in);
assert(state);
/* Update total length */
state->inlen += inlen;
/* If padding exists, fill it out */
if (left > 0) {
for ( ; in < end && left < 8; in ++, left ++)
state->padding |= ((uint64_t) *in) << (left * 8);
if (in == end && left < 8)
/* We did not have enough input to fill out the padding completely */
return;
#if ENABLE_DEBUG_SIPHASH
printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding);
#endif
state->v3 ^= state->padding;
sipround(state);
sipround(state);
state->v0 ^= state->padding;
state->padding = 0;
}
end -= (state->inlen % sizeof(uint64_t));
for ( ; in < end; in += 8) {
m = unaligned_read_le64(in);
#if ENABLE_DEBUG_SIPHASH
printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m);
#endif
state->v3 ^= m;
sipround(state);
sipround(state);
state->v0 ^= m;
}
left = state->inlen & 7;
switch (left) {
case 7:
state->padding |= ((uint64_t) in[6]) << 48;
_fallthrough_;
case 6:
state->padding |= ((uint64_t) in[5]) << 40;
_fallthrough_;
case 5:
state->padding |= ((uint64_t) in[4]) << 32;
_fallthrough_;
case 4:
state->padding |= ((uint64_t) in[3]) << 24;
_fallthrough_;
case 3:
state->padding |= ((uint64_t) in[2]) << 16;
_fallthrough_;
case 2:
state->padding |= ((uint64_t) in[1]) << 8;
_fallthrough_;
case 1:
state->padding |= ((uint64_t) in[0]);
_fallthrough_;
case 0:
break;
}
}
uint64_t siphash24_finalize(struct siphash *state) {
uint64_t b;
assert(state);
b = state->padding | (((uint64_t) state->inlen) << 56);
#if ENABLE_DEBUG_SIPHASH
printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
printf("(%3zu) padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding);
#endif
state->v3 ^= b;
sipround(state);
sipround(state);
state->v0 ^= b;
#if ENABLE_DEBUG_SIPHASH
printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
#endif
state->v2 ^= 0xff;
sipround(state);
sipround(state);
sipround(state);
sipround(state);
return state->v0 ^ state->v1 ^ state->v2 ^ state->v3;
}
uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]) {
struct siphash state;
assert(in);
assert(k);
siphash24_init(&state, k);
siphash24_compress(in, inlen, &state);
return siphash24_finalize(&state);
}
|
