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 #include "../internal.h"
21
22
siphash_round(uint64_t v[4])23 static void siphash_round(uint64_t v[4]) {
24 v[0] += v[1];
25 v[2] += v[3];
26 v[1] = (v[1] << 13) | (v[1] >> (64 - 13));
27 v[3] = (v[3] << 16) | (v[3] >> (64 - 16));
28 v[1] ^= v[0];
29 v[3] ^= v[2];
30 v[0] = (v[0] << 32) | (v[0] >> 32);
31 v[2] += v[1];
32 v[0] += v[3];
33 v[1] = (v[1] << 17) | (v[1] >> (64 - 17));
34 v[3] = (v[3] << 21) | (v[3] >> (64 - 21));
35 v[1] ^= v[2];
36 v[3] ^= v[0];
37 v[2] = (v[2] << 32) | (v[2] >> 32);
38 }
39
SIPHASH_24(const uint64_t key[2],const uint8_t * input,size_t input_len)40 uint64_t SIPHASH_24(const uint64_t key[2], const uint8_t *input,
41 size_t input_len) {
42 const size_t orig_input_len = input_len;
43
44 uint64_t v[4];
45 v[0] = key[0] ^ UINT64_C(0x736f6d6570736575);
46 v[1] = key[1] ^ UINT64_C(0x646f72616e646f6d);
47 v[2] = key[0] ^ UINT64_C(0x6c7967656e657261);
48 v[3] = key[1] ^ UINT64_C(0x7465646279746573);
49
50 while (input_len >= sizeof(uint64_t)) {
51 uint64_t m;
52 memcpy(&m, input, sizeof(m));
53 v[3] ^= m;
54 siphash_round(v);
55 siphash_round(v);
56 v[0] ^= m;
57
58 input += sizeof(uint64_t);
59 input_len -= sizeof(uint64_t);
60 }
61
62 union {
63 uint8_t bytes[8];
64 uint64_t word;
65 } last_block;
66 last_block.word = 0;
67 OPENSSL_memcpy(last_block.bytes, input, input_len);
68 last_block.bytes[7] = orig_input_len & 0xff;
69
70 v[3] ^= last_block.word;
71 siphash_round(v);
72 siphash_round(v);
73 v[0] ^= last_block.word;
74
75 v[2] ^= 0xff;
76 siphash_round(v);
77 siphash_round(v);
78 siphash_round(v);
79 siphash_round(v);
80
81 return v[0] ^ v[1] ^ v[2] ^ v[3];
82 }
83