1 // SPDX-License-Identifier: BSD-3-Clause 1
2 /* $OpenBSD: siphash.c,v 1.3 2015/02/20 1
3
4 /*-
5 * Copyright (c) 2013 Andre Oppermann <andre@F
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary
9 * modification, are permitted provided that t
10 * are met:
11 * 1. Redistributions of source code must reta
12 * notice, this list of conditions and the
13 * 2. Redistributions in binary form must repr
14 * notice, this list of conditions and the
15 * documentation and/or other materials pro
16 * 3. The name of the author may not be used t
17 * products derived from this software with
18 * permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDIN
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND F
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTH
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECI
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PRO
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILI
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF AD
30 * SUCH DAMAGE.
31 */
32
33 /*
34 * SipHash is a family of PRFs SipHash-c-d whe
35 * are the number of compression rounds and th
36 * A compression round is identical to a final
37 * function is called SipRound. Given a 128-b
38 * byte string m, SipHash-c-d returns a 64-bit
39 *
40 * Implemented from the paper "SipHash: a fast
41 * by Jean-Philippe Aumasson and Daniel J. Ber
42 * Permanent Document ID b9a943a805fbfc6fde808
43 * https://131002.net/siphash/siphash.pdf
44 * https://131002.net/siphash/
45 */
46
47 #include <asm/byteorder.h>
48 #include <linux/unaligned.h>
49 #include <linux/bitops.h>
50 #include <linux/string.h>
51
52 #include "siphash.h"
53
54 static void SipHash_Rounds(SIPHASH_CTX *ctx, i
55 {
56 while (rounds--) {
57 ctx->v[0] += ctx->v[1];
58 ctx->v[2] += ctx->v[3];
59 ctx->v[1] = rol64(ctx->v[1], 1
60 ctx->v[3] = rol64(ctx->v[3], 1
61
62 ctx->v[1] ^= ctx->v[0];
63 ctx->v[3] ^= ctx->v[2];
64 ctx->v[0] = rol64(ctx->v[0], 3
65
66 ctx->v[2] += ctx->v[1];
67 ctx->v[0] += ctx->v[3];
68 ctx->v[1] = rol64(ctx->v[1], 1
69 ctx->v[3] = rol64(ctx->v[3], 2
70
71 ctx->v[1] ^= ctx->v[2];
72 ctx->v[3] ^= ctx->v[0];
73 ctx->v[2] = rol64(ctx->v[2], 3
74 }
75 }
76
77 static void SipHash_CRounds(SIPHASH_CTX *ctx,
78 {
79 u64 m = get_unaligned_le64(ptr);
80
81 ctx->v[3] ^= m;
82 SipHash_Rounds(ctx, rounds);
83 ctx->v[0] ^= m;
84 }
85
86 void SipHash_Init(SIPHASH_CTX *ctx, const SIPH
87 {
88 u64 k0, k1;
89
90 k0 = le64_to_cpu(key->k0);
91 k1 = le64_to_cpu(key->k1);
92
93 ctx->v[0] = 0x736f6d6570736575ULL ^ k0
94 ctx->v[1] = 0x646f72616e646f6dULL ^ k1
95 ctx->v[2] = 0x6c7967656e657261ULL ^ k0
96 ctx->v[3] = 0x7465646279746573ULL ^ k1
97
98 memset(ctx->buf, 0, sizeof(ctx->buf));
99 ctx->bytes = 0;
100 }
101
102 void SipHash_Update(SIPHASH_CTX *ctx, int rc,
103 const void *src, size_t le
104 {
105 const u8 *ptr = src;
106 size_t left, used;
107
108 if (len == 0)
109 return;
110
111 used = ctx->bytes % sizeof(ctx->buf);
112 ctx->bytes += len;
113
114 if (used > 0) {
115 left = sizeof(ctx->buf) - used
116
117 if (len >= left) {
118 memcpy(&ctx->buf[used]
119 SipHash_CRounds(ctx, c
120 len -= left;
121 ptr += left;
122 } else {
123 memcpy(&ctx->buf[used]
124 return;
125 }
126 }
127
128 while (len >= sizeof(ctx->buf)) {
129 SipHash_CRounds(ctx, ptr, rc);
130 len -= sizeof(ctx->buf);
131 ptr += sizeof(ctx->buf);
132 }
133
134 if (len > 0)
135 memcpy(&ctx->buf[used], ptr, l
136 }
137
138 void SipHash_Final(void *dst, SIPHASH_CTX *ctx
139 {
140 u64 r;
141
142 r = SipHash_End(ctx, rc, rf);
143
144 *((__le64 *) dst) = cpu_to_le64(r);
145 }
146
147 u64 SipHash_End(SIPHASH_CTX *ctx, int rc, int
148 {
149 u64 r;
150 size_t left, used;
151
152 used = ctx->bytes % sizeof(ctx->buf);
153 left = sizeof(ctx->buf) - used;
154 memset(&ctx->buf[used], 0, left - 1);
155 ctx->buf[7] = ctx->bytes;
156
157 SipHash_CRounds(ctx, ctx->buf, rc);
158 ctx->v[2] ^= 0xff;
159 SipHash_Rounds(ctx, rf);
160
161 r = (ctx->v[0] ^ ctx->v[1]) ^ (ctx->v[
162 memset(ctx, 0, sizeof(*ctx));
163 return r;
164 }
165
166 u64 SipHash(const SIPHASH_KEY *key, int rc, in
167 {
168 SIPHASH_CTX ctx;
169
170 SipHash_Init(&ctx, key);
171 SipHash_Update(&ctx, rc, rf, src, len)
172 return SipHash_End(&ctx, rc, rf);
173 }
174
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