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
20 #include "sparse-endian.h"
22 #include "siphash24.h"
23 #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 = le64toh(*(le64_t*) k);
58 k1 = le64toh(*(le64_t*) (k + 8));
60 /* "somepseudorandomlygeneratedbytes" */
61 state->v0 = 0x736f6d6570736575ULL ^ k0;
62 state->v1 = 0x646f72616e646f6dULL ^ k1;
63 state->v2 = 0x6c7967656e657261ULL ^ k0;
64 state->v3 = 0x7465646279746573ULL ^ k1;
69 void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
71 const uint8_t *in = _in;
72 const uint8_t *end = in + inlen;
73 unsigned left = state->inlen & 7;
78 /* update total length */
79 state->inlen += inlen;
81 /* if padding exists, fill it out */
83 for ( ; in < end && left < 8; in ++, left ++ )
84 state->padding |= ( ( uint64_t )*in ) << (left * 8);
86 if (in == end && left < 8)
87 /* we did not have enough input to fill out the padding completely */
91 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
92 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
93 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
94 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
95 printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding);
97 state->v3 ^= state->padding;
100 state->v0 ^= state->padding;
105 end -= ( state->inlen % sizeof (uint64_t) );
107 for ( ; in < end; in += 8 ) {
108 m = unaligned_read_le64(in);
110 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
111 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
112 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
113 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
114 printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m);
122 left = state->inlen & 7;
126 case 7: state->padding |= ((uint64_t) in[6]) << 48;
128 case 6: state->padding |= ((uint64_t) in[5]) << 40;
130 case 5: state->padding |= ((uint64_t) in[4]) << 32;
132 case 4: state->padding |= ((uint64_t) in[3]) << 24;
134 case 3: state->padding |= ((uint64_t) in[2]) << 16;
136 case 2: state->padding |= ((uint64_t) in[1]) << 8;
138 case 1: state->padding |= ((uint64_t) in[0]); break;
144 void siphash24_finalize(uint8_t out[8], struct siphash *state) {
147 b = state->padding | (( ( uint64_t )state->inlen ) << 56);
149 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t)state->v0);
150 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t)state->v1);
151 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t)state->v2);
152 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t)state->v3);
153 printf("(%3zu) padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding);
161 printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
162 printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
163 printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
164 printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
173 *(le64_t*)out = htole64(state->v0 ^ state->v1 ^ state->v2 ^ state->v3);
177 void siphash24(uint8_t out[8], const void *_in, size_t inlen, const uint8_t k[16]) {
178 struct siphash state;
180 siphash24_init(&state, k);
181 siphash24_compress(_in, inlen, &state);
182 siphash24_finalize(out, &state);