/src/systemd/src/basic/siphash24.c

Source
/* 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 "siphash24.h"
#include "string-util.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 = ASSERT_PTR(_in);
        const uint8_t *end = in + inlen;
        size_t left = state->inlen & 7;
        uint64_t m;

        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;
        }
}

void siphash24_compress_string(const char *in, struct siphash *state) {
        siphash24_compress_safe(in, strlen_ptr(in), state);
}

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);
}

uint64_t siphash24_string(const char *s, const uint8_t k[static 16]) {
        return siphash24(s, strlen(s) + 1, k);
}

Coverage Report

Created: 2026-04-29 07:06

Line	Count	Source
1		/* SPDX-License-Identifier: CC0-1.0 */
2
3		/*
4		SipHash reference C implementation
5
6		Written in 2012 by
7		Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
8		Daniel J. Bernstein <djb@cr.yp.to>
9
10		To the extent possible under law, the author(s) have dedicated all copyright
11		and related and neighboring rights to this software to the public domain
12		worldwide. This software is distributed without any warranty.
13
14		You should have received a copy of the CC0 Public Domain Dedication along with
15		this software. If not, see <https://creativecommons.org/publicdomain/zero/1.0/>.
16
17		(Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd)
18		(Refactored by Tom Gundersen to split up in several functions and follow systemd
19		coding style)
20		*/
21
22		#include <stdio.h>
23
24		#include "siphash24.h"
25		#include "string-util.h"
26		#include "unaligned.h"
27
28	5.30G	static uint64_t rotate_left(uint64_t x, uint8_t b) {
29	5.30G	assert(b < 64);
30
31	5.30G	return (x << b) \| (x >> (64 - b));
32	5.30G	}
33
34	884M	static void sipround(struct siphash *state) {
35	884M	assert(state);
36
37	884M	state->v0 += state->v1;
38	884M	state->v1 = rotate_left(state->v1, 13);
39	884M	state->v1 ^= state->v0;
40	884M	state->v0 = rotate_left(state->v0, 32);
41	884M	state->v2 += state->v3;
42	884M	state->v3 = rotate_left(state->v3, 16);
43	884M	state->v3 ^= state->v2;
44	884M	state->v0 += state->v3;
45	884M	state->v3 = rotate_left(state->v3, 21);
46	884M	state->v3 ^= state->v0;
47	884M	state->v2 += state->v1;
48	884M	state->v1 = rotate_left(state->v1, 17);
49	884M	state->v1 ^= state->v2;
50	884M	state->v2 = rotate_left(state->v2, 32);
51	884M	}
52
53	101M	void siphash24_init(struct siphash *state, const uint8_t k[static 16]) {
54	101M	uint64_t k0, k1;
55
56	101M	assert(state);
57	101M	assert(k);
58
59	101M	k0 = unaligned_read_le64(k);
60	101M	k1 = unaligned_read_le64(k + 8);
61
62	101M	*state = (struct siphash) {
63		/* "somepseudorandomlygeneratedbytes" */
64	101M	.v0 = 0x736f6d6570736575ULL ^ k0,
65	101M	.v1 = 0x646f72616e646f6dULL ^ k1,
66	101M	.v2 = 0x6c7967656e657261ULL ^ k0,
67	101M	.v3 = 0x7465646279746573ULL ^ k1,
68	101M	.padding = 0,
69	101M	.inlen = 0,
70	101M	};
71	101M	}
72
73	156M	void siphash24_compress(const void _in, size_t inlen, struct siphash state) {
74
75	156M	const uint8_t *in = ASSERT_PTR(_in);
76	156M	const uint8_t *end = in + inlen;
77	156M	size_t left = state->inlen & 7;
78	156M	uint64_t m;
79
80	156M	assert(state);
81
82		/* Update total length */
83	156M	state->inlen += inlen;
84
85		/* If padding exists, fill it out */
86	156M	if (left > 0) {
87	147M	for ( ; in < end && left < 8; in ++, left ++)
88	96.4M	state->padding \|= ((uint64_t) in) << (left 8);
89
90	50.6M	if (in == end && left < 8)
91		/* We did not have enough input to fill out the padding completely */
92	36.5M	return;
93
94		#if ENABLE_DEBUG_SIPHASH
95		printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
96		printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
97		printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
98		printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
99		printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding);
100		#endif
101
102	14.1M	state->v3 ^= state->padding;
103	14.1M	sipround(state);
104	14.1M	sipround(state);
105	14.1M	state->v0 ^= state->padding;
106
107	14.1M	state->padding = 0;
108	14.1M	}
109
110	120M	end -= (state->inlen % sizeof(uint64_t));
111
112	245M	for ( ; in < end; in += 8) {
113	125M	m = unaligned_read_le64(in);
114		#if ENABLE_DEBUG_SIPHASH
115		printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
116		printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
117		printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
118		printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
119		printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m);
120		#endif
121	125M	state->v3 ^= m;
122	125M	sipround(state);
123	125M	sipround(state);
124	125M	state->v0 ^= m;
125	125M	}
126
127	120M	left = state->inlen & 7;
128	120M	switch (left) {
129	1.00M	case 7:
130	1.00M	state->padding \|= ((uint64_t) in[6]) << 48;
131	1.00M	_fallthrough_;
132	7.53M	case 6:
133	7.53M	state->padding \|= ((uint64_t) in[5]) << 40;
134	7.53M	_fallthrough_;
135	14.2M	case 5:
136	14.2M	state->padding \|= ((uint64_t) in[4]) << 32;
137	14.2M	_fallthrough_;
138	22.6M	case 4:
139	22.6M	state->padding \|= ((uint64_t) in[3]) << 24;
140	22.6M	_fallthrough_;
141	27.4M	case 3:
142	27.4M	state->padding \|= ((uint64_t) in[2]) << 16;
143	27.4M	_fallthrough_;
144	36.1M	case 2:
145	36.1M	state->padding \|= ((uint64_t) in[1]) << 8;
146	36.1M	_fallthrough_;
147	60.9M	case 1:
148	60.9M	state->padding \|= ((uint64_t) in[0]);
149	60.9M	_fallthrough_;
150	120M	case 0:
151	120M	break;
152	120M	}
153	120M	}
154
155	2.86M	void siphash24_compress_string(const char in, struct siphash state) {
156	2.86M	siphash24_compress_safe(in, strlen_ptr(in), state);
157	2.86M	}
158
159	101M	uint64_t siphash24_finalize(struct siphash *state) {
160	101M	uint64_t b;
161
162	101M	assert(state);
163
164	101M	b = state->padding \| (((uint64_t) state->inlen) << 56);
165
166		#if ENABLE_DEBUG_SIPHASH
167		printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
168		printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
169		printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
170		printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
171		printf("(%3zu) padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding);
172		#endif
173
174	101M	state->v3 ^= b;
175	101M	sipround(state);
176	101M	sipround(state);
177	101M	state->v0 ^= b;
178
179		#if ENABLE_DEBUG_SIPHASH
180		printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
181		printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
182		printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
183		printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
184		#endif
185	101M	state->v2 ^= 0xff;
186
187	101M	sipround(state);
188	101M	sipround(state);
189	101M	sipround(state);
190	101M	sipround(state);
191
192	101M	return state->v0 ^ state->v1 ^ state->v2 ^ state->v3;
193	101M	}
194
195	614k	uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]) {
196	614k	struct siphash state;
197
198	614k	assert(in);
199	614k	assert(k);
200
201	614k	siphash24_init(&state, k);
202	614k	siphash24_compress(in, inlen, &state);
203
204	614k	return siphash24_finalize(&state);
205	614k	}
206
207	0	uint64_t siphash24_string(const char *s, const uint8_t k[static 16]) {
208	0	return siphash24(s, strlen(s) + 1, k);
209	0	}