2 SipHash reference C implementation
5 Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
6 Daniel J. Bernstein <djb@cr.yp.to>
8 To the extent possible under law, the author(s) have dedicated all copyright
9 and related and neighboring rights to this software to the public domain
10 worldwide. This software is distributed without any warranty.
12 You should have received a copy of the CC0 Public Domain Dedication along with
13 this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
15 (Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd)
16 (Refactored by Tom Gundersen to split up in several functions and follow systemd
23 #include "siphash24.h"
24 #include "unaligned.h"
26 static inline uint64_t rotate_left(uint64_t x, uint8_t b) {
29 return (x << b) | (x >> (64 - b));
32 static inline void sipround(struct siphash *state) {
35 state->v0 += state->v1;
36 state->v1 = rotate_left(state->v1, 13);
37 state->v1 ^= state->v0;
38 state->v0 = rotate_left(state->v0, 32);
39 state->v2 += state->v3;
40 state->v3 = rotate_left(state->v3, 16);
41 state->v3 ^= state->v2;
42 state->v0 += state->v3;
43 state->v3 = rotate_left(state->v3, 21);
44 state->v3 ^= state->v0;
45 state->v2 += state->v1;
46 state->v1 = rotate_left(state->v1, 17);
47 state->v1 ^= state->v2;
48 state->v2 = rotate_left(state->v2, 32);
51 void siphash24_init(struct siphash *state, const uint8_t k[16]) {
57 k0 = unaligned_read_le64(k);
58 k1 = unaligned_read_le64(k + 8);
60 *state = (struct siphash) {
61 /* "somepseudorandomlygeneratedbytes" */
62 .v0 = 0x736f6d6570736575ULL ^ k0,
63 .v1 = 0x646f72616e646f6dULL ^ k1,
64 .v2 = 0x6c7967656e657261ULL ^ k0,
65 .v3 = 0x7465646279746573ULL ^ k1,
71 void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
73 const uint8_t *in = _in;
74 const uint8_t *end = in + inlen;
75 size_t left = state->inlen & 7;
81 /* Update total length */
82 state->inlen += inlen;
84 /* If padding exists, fill it out */
86 for ( ; in < end && left < 8; in ++, left ++)
87 state->padding |= ((uint64_t) *in) << (left * 8);
89 if (in == end && left < 8)
90 /* We did not have enough input to fill out the padding completely */
94 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
95 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
96 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
97 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
98 printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding);
101 state->v3 ^= state->padding;
104 state->v0 ^= state->padding;
109 end -= (state->inlen % sizeof(uint64_t));
111 for ( ; in < end; in += 8) {
112 m = unaligned_read_le64(in);
114 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
115 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
116 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
117 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
118 printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m);
126 left = state->inlen & 7;
129 state->padding |= ((uint64_t) in[6]) << 48;
131 state->padding |= ((uint64_t) in[5]) << 40;
133 state->padding |= ((uint64_t) in[4]) << 32;
135 state->padding |= ((uint64_t) in[3]) << 24;
137 state->padding |= ((uint64_t) in[2]) << 16;
139 state->padding |= ((uint64_t) in[1]) << 8;
141 state->padding |= ((uint64_t) in[0]);
147 uint64_t siphash24_finalize(struct siphash *state) {
152 b = state->padding | (((uint64_t) state->inlen) << 56);
155 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
156 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
157 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
158 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
159 printf("(%3zu) padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding);
168 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
169 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
170 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
171 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
180 return state->v0 ^ state->v1 ^ state->v2 ^ state->v3;
183 uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[16]) {
184 struct siphash state;
189 siphash24_init(&state, k);
190 siphash24_compress(in, inlen, &state);
192 return siphash24_finalize(&state);