1 /*-
2 * Copyright (c) 2013 Andre Oppermann <andre@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote
14 * products derived from this software without specific prior written
15 * permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * SipHash is a family of PRFs SipHash-c-d where the integer parameters c and d
32 * are the number of compression rounds and the number of finalization rounds.
33 * A compression round is identical to a finalization round and this round
34 * function is called SipRound. Given a 128-bit key k and a (possibly empty)
35 * byte string m, SipHash-c-d returns a 64-bit value SipHash-c-d(k; m).
36 *
37 * Implemented from the paper "SipHash: a fast short-input PRF", 2012.09.18,
38 * by Jean-Philippe Aumasson and Daniel J. Bernstein,
39 * Permanent Document ID b9a943a805fbfc6fde808af9fc0ecdfa
40 * https://131002.net/siphash/siphash.pdf
41 * https://131002.net/siphash/
42 */
43
44 #include <sys/param.h>
45 #include <sys/types.h>
46 #include <sys/systm.h>
47 #include <sys/libkern.h>
48 #include <sys/endian.h>
49
50 #include <crypto/siphash/siphash.h>
51
52 static void SipRounds(SIPHASH_CTX *ctx, int final);
53
54 void
SipHash_InitX(SIPHASH_CTX * ctx,int rc,int rf)55 SipHash_InitX(SIPHASH_CTX *ctx, int rc, int rf)
56 {
57
58 ctx->v[0] = 0x736f6d6570736575ull;
59 ctx->v[1] = 0x646f72616e646f6dull;
60 ctx->v[2] = 0x6c7967656e657261ull;
61 ctx->v[3] = 0x7465646279746573ull;
62 ctx->buf.b64 = 0;
63 ctx->bytes = 0;
64 ctx->buflen = 0;
65 ctx->rounds_compr = rc;
66 ctx->rounds_final = rf;
67 ctx->initialized = 1;
68 }
69
70 void
SipHash_SetKey(SIPHASH_CTX * ctx,const uint8_t key[static SIPHASH_KEY_LENGTH])71 SipHash_SetKey(SIPHASH_CTX *ctx, const uint8_t key[static SIPHASH_KEY_LENGTH])
72 {
73 uint64_t k[2];
74
75 KASSERT(ctx->v[0] == 0x736f6d6570736575ull &&
76 ctx->initialized == 1,
77 ("%s: context %p not properly initialized", __func__, ctx));
78
79 k[0] = le64dec(&key[0]);
80 k[1] = le64dec(&key[8]);
81
82 ctx->v[0] ^= k[0];
83 ctx->v[1] ^= k[1];
84 ctx->v[2] ^= k[0];
85 ctx->v[3] ^= k[1];
86
87 ctx->initialized = 2;
88 }
89
90 static size_t
SipBuf(SIPHASH_CTX * ctx,const uint8_t ** src,size_t len,int final)91 SipBuf(SIPHASH_CTX *ctx, const uint8_t **src, size_t len, int final)
92 {
93 size_t x = 0;
94
95 KASSERT((!final && len > 0) || (final && len == 0),
96 ("%s: invalid parameters", __func__));
97
98 if (!final) {
99 x = MIN(len, sizeof(ctx->buf.b64) - ctx->buflen);
100 bcopy(*src, &ctx->buf.b8[ctx->buflen], x);
101 ctx->buflen += x;
102 *src += x;
103 } else
104 ctx->buf.b8[7] = (uint8_t)ctx->bytes;
105
106 if (ctx->buflen == 8 || final) {
107 ctx->v[3] ^= le64toh(ctx->buf.b64);
108 SipRounds(ctx, 0);
109 ctx->v[0] ^= le64toh(ctx->buf.b64);
110 ctx->buf.b64 = 0;
111 ctx->buflen = 0;
112 }
113 return (x);
114 }
115
116 void
SipHash_Update(SIPHASH_CTX * ctx,const void * src,size_t len)117 SipHash_Update(SIPHASH_CTX *ctx, const void *src, size_t len)
118 {
119 uint64_t m;
120 const uint64_t *p;
121 const uint8_t *s;
122 size_t rem;
123
124 KASSERT(ctx->initialized == 2,
125 ("%s: context %p not properly initialized", __func__, ctx));
126
127 s = src;
128 ctx->bytes += len;
129
130 /*
131 * Push length smaller than block size into buffer or
132 * fill up the buffer if there is already something
133 * in it.
134 */
135 if (ctx->buflen > 0 || len < 8)
136 len -= SipBuf(ctx, &s, len, 0);
137 if (len == 0)
138 return;
139
140 rem = len & 0x7;
141 len >>= 3;
142
143 /* Optimze for 64bit aligned/unaligned access. */
144 if (((uintptr_t)s & 0x7) == 0) {
145 for (p = (const uint64_t *)s; len > 0; len--, p++) {
146 m = le64toh(*p);
147 ctx->v[3] ^= m;
148 SipRounds(ctx, 0);
149 ctx->v[0] ^= m;
150 }
151 s = (const uint8_t *)p;
152 } else {
153 for (; len > 0; len--, s += 8) {
154 m = le64dec(s);
155 ctx->v[3] ^= m;
156 SipRounds(ctx, 0);
157 ctx->v[0] ^= m;
158 }
159 }
160
161 /* Push remainder into buffer. */
162 if (rem > 0)
163 (void)SipBuf(ctx, &s, rem, 0);
164 }
165
166 void
SipHash_Final(uint8_t dst[static SIPHASH_DIGEST_LENGTH],SIPHASH_CTX * ctx)167 SipHash_Final(uint8_t dst[static SIPHASH_DIGEST_LENGTH], SIPHASH_CTX *ctx)
168 {
169 uint64_t r;
170
171 KASSERT(ctx->initialized == 2,
172 ("%s: context %p not properly initialized", __func__, ctx));
173
174 r = SipHash_End(ctx);
175 le64enc(dst, r);
176 }
177
178 uint64_t
SipHash_End(SIPHASH_CTX * ctx)179 SipHash_End(SIPHASH_CTX *ctx)
180 {
181 uint64_t r;
182
183 KASSERT(ctx->initialized == 2,
184 ("%s: context %p not properly initialized", __func__, ctx));
185
186 SipBuf(ctx, NULL, 0, 1);
187 ctx->v[2] ^= 0xff;
188 SipRounds(ctx, 1);
189 r = (ctx->v[0] ^ ctx->v[1]) ^ (ctx->v[2] ^ ctx->v[3]);
190
191 bzero(ctx, sizeof(*ctx));
192 return (r);
193 }
194
195 uint64_t
SipHashX(SIPHASH_CTX * ctx,int rc,int rf,const uint8_t key[static SIPHASH_KEY_LENGTH],const void * src,size_t len)196 SipHashX(SIPHASH_CTX *ctx, int rc, int rf,
197 const uint8_t key[static SIPHASH_KEY_LENGTH], const void *src, size_t len)
198 {
199
200 SipHash_InitX(ctx, rc, rf);
201 SipHash_SetKey(ctx, key);
202 SipHash_Update(ctx, src, len);
203
204 return (SipHash_End(ctx));
205 }
206
207 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
208
209 static void
SipRounds(SIPHASH_CTX * ctx,int final)210 SipRounds(SIPHASH_CTX *ctx, int final)
211 {
212 int rounds;
213
214 if (!final)
215 rounds = ctx->rounds_compr;
216 else
217 rounds = ctx->rounds_final;
218
219 while (rounds--) {
220 ctx->v[0] += ctx->v[1];
221 ctx->v[2] += ctx->v[3];
222 ctx->v[1] = SIP_ROTL(ctx->v[1], 13);
223 ctx->v[3] = SIP_ROTL(ctx->v[3], 16);
224
225 ctx->v[1] ^= ctx->v[0];
226 ctx->v[3] ^= ctx->v[2];
227 ctx->v[0] = SIP_ROTL(ctx->v[0], 32);
228
229 ctx->v[2] += ctx->v[1];
230 ctx->v[0] += ctx->v[3];
231 ctx->v[1] = SIP_ROTL(ctx->v[1], 17);
232 ctx->v[3] = SIP_ROTL(ctx->v[3], 21);
233
234 ctx->v[1] ^= ctx->v[2];
235 ctx->v[3] ^= ctx->v[0];
236 ctx->v[2] = SIP_ROTL(ctx->v[2], 32);
237 }
238 }
239
240