1/* Copyright (c) 2019, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15#include <stdint.h>
16#include <string.h>
17
18#include <openssl/siphash.h>
19
20
21static void siphash_round(uint64_t v[4]) {
22 v[0] += v[1];
23 v[2] += v[3];
24 v[1] = (v[1] << 13) | (v[1] >> (64 - 13));
25 v[3] = (v[3] << 16) | (v[3] >> (64 - 16));
26 v[1] ^= v[0];
27 v[3] ^= v[2];
28 v[0] = (v[0] << 32) | (v[0] >> 32);
29 v[2] += v[1];
30 v[0] += v[3];
31 v[1] = (v[1] << 17) | (v[1] >> (64 - 17));
32 v[3] = (v[3] << 21) | (v[3] >> (64 - 21));
33 v[1] ^= v[2];
34 v[3] ^= v[0];
35 v[2] = (v[2] << 32) | (v[2] >> 32);
36}
37
38uint64_t SIPHASH_24(const uint64_t key[2], const uint8_t *input,
39 size_t input_len) {
40 const size_t orig_input_len = input_len;
41
42 uint64_t v[4];
43 v[0] = key[0] ^ UINT64_C(0x736f6d6570736575);
44 v[1] = key[1] ^ UINT64_C(0x646f72616e646f6d);
45 v[2] = key[0] ^ UINT64_C(0x6c7967656e657261);
46 v[3] = key[1] ^ UINT64_C(0x7465646279746573);
47
48 while (input_len >= sizeof(uint64_t)) {
49 uint64_t m;
50 memcpy(&m, input, sizeof(m));
51 v[3] ^= m;
52 siphash_round(v);
53 siphash_round(v);
54 v[0] ^= m;
55
56 input += sizeof(uint64_t);
57 input_len -= sizeof(uint64_t);
58 }
59
60 union {
61 uint8_t bytes[8];
62 uint64_t word;
63 } last_block;
64 last_block.word = 0;
65 memcpy(last_block.bytes, input, input_len);
66 last_block.bytes[7] = orig_input_len & 0xff;
67
68 v[3] ^= last_block.word;
69 siphash_round(v);
70 siphash_round(v);
71 v[0] ^= last_block.word;
72
73 v[2] ^= 0xff;
74 siphash_round(v);
75 siphash_round(v);
76 siphash_round(v);
77 siphash_round(v);
78
79 return v[0] ^ v[1] ^ v[2] ^ v[3];
80}
81