-
Notifications
You must be signed in to change notification settings - Fork 574
/
Copy pathperl_siphash.h
319 lines (261 loc) · 11.8 KB
/
perl_siphash.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/* This is SipHash by Jean-Philippe Aumasson and Daniel J. Bernstein.
* The authors claim it is relatively secure compared to the alternatives
* and that performance wise it is a suitable hash for languages like Perl.
* See:
*
* https://www.131002.net/siphash/
*
* Naming convention:
*
* S_perl_hash_siphash_N_M: the N refers to how many rounds are performed per
* block. The M refers to how many rounds are performed as part of the
* finalizer. Increased values of either improve security, but decrease
* performance.
*
* _with_state: these functions take a 32 bit state vector prepared by
* S_perl_siphash_seed_state(). Functions without 'with_state' take a 16
* byte seed vector and call S_perl_siphash_seed_state() implicitly. If
* you are hashing many things with the same seed, the _with_state
* variants are faster.
*
* _64: returns a 64 bit hash
*
* no-suffix: returns a 32 bit hash.
*
* This file defines 9 functions related to implementing 2 variants of
* the Siphash family of hash functions, Siphash-2-4, and Siphash-1-3.
=for apidoc_section $numeric
=for apidoc eST|void|S_perl_siphash_seed_state \
|const unsigned char * const seed_buf \
|unsigned char * state_buf
Takes a 16 byte seed and converts it into a 32 byte state buffer. The
contents of state_buf will be overwritten.
If you need to hash a lot of things, then you can use this to process
the seed once, and then reuse the state over and over.
The siphash functions which take a seed argument will call this function
implicitly every time they are used. Those which take a state argument
require the seed to be converted into a state before they are used.
See the various _with_state siphash functions for a usage example.
=for apidoc eSTP|U64|S_perl_hash_siphash_1_3_with_state_64\
|const unsigned char * const state \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.
Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 64 bit hash.
The following code should return 0xB70339FD9E758A5C
U8 state[32];
char seed[] = "Call me Ishmael.";
S_perl_siphash_seed_state((const U8*)seed, state);
char in[] = "It is not down on any map; true places never are.";
U64 hash = S_perl_hash_siphash_1_3_with_state_64(
state, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U32|S_perl_hash_siphash_1_3_with_state\
|const unsigned char * const state \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.
Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 32 bit hash.
The following code should return 0x2976B3A1
U8 state[32];
char seed[] = "Call me Ishmael.";
S_perl_siphash_seed_state((const U8*)seed, state);
char in[] = "It is not down on any map; true places never are.";
U32 hash = S_perl_hash_siphash_1_3_with_state(
state, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U64|S_perl_hash_siphash_1_3_64\
|const unsigned char * const seed \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.
Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 64 bit hash.
The following code should return 0xB70339FD9E758A5C
char seed[] = "Call me Ishmael.";
char in[] = "It is not down on any map; true places never are.";
U64 hash = S_perl_hash_siphash_1_3_64(
(const U8*)seed, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U64|S_perl_hash_siphash_1_3\
|const unsigned char * const seed \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 1 round function
per block, and 3 as part of the finalizer.
Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 32 bit hash.
The following code should return 0x2976B3A1
char seed[] = "Call me Ishmael.";
char in[] = "It is not down on any map; true places never are.";
U32 hash = S_perl_hash_siphash_1_3(
(const U8*)seed, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U64|S_perl_hash_siphash_2_4_with_state_64\
|const unsigned char * const state \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 2 round functions
per block, and 4 as part of the finalizer.
Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 64 bit hash.
The following code should return 0x1E84CF1D7AA516B7
U8 state[32];
char seed[] = "Call me Ishmael.";
S_perl_siphash_seed_state((const U8*)seed, state);
char in[] = "It is not down on any map; true places never are.";
U64 hash = S_perl_hash_siphash_2_4_with_state_64(
state, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U32|S_perl_hash_siphash_2_4_with_state\
|const unsigned char * const state \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 2 round function
per block, and 4 as part of the finalizer.
Takes a 32 byte 'state' vector prepared by S_perl_siphash_seed_state()
and uses it to hash C<inlen> bytes from the buffer pointed to by C<in>,
returns a 32 bit hash.
The following code should return 0x6421D9AA
U8 state[32];
char seed[] = "Call me Ishmael.";
S_perl_siphash_seed_state((const U8*)seed, state);
char in[] = "It is not down on any map; true places never are.";
U32 hash = S_perl_hash_siphash_2_4_with_state(
state, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U64|S_perl_hash_siphash_2_4_64\
|const unsigned char * const seed \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 2 round functions
per block, and 4 as part of the finalizer.
Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 64 bit hash.
The following code should return 0x1E84CF1D7AA516B7
char seed[] = "Call me Ishmael.";
char in[] = "It is not down on any map; true places never are.";
U64 hash = S_perl_hash_siphash_2_4_64(
(const U8*)seed, (const U8*)in, sizeof(in)-1);
=for apidoc eSTP|U32|S_perl_hash_siphash_2_4\
|const unsigned char * const seed \
|const unsigned char *in|const STRLEN inlen
Implements the variant of Siphash which performs 2 round functions
per block, and 4 as part of the finalizer.
Takes a 16 byte C<seed> vector, and uses it to hash C<inlen> bytes
from the buffer pointed to by C<in>, returns a 32 bit hash.
The following code should return 0x6421D9AA
char seed[] = "Call me Ishmael.";
char in[] = "It is not down on any map; true places never are.";
U32 hash = S_perl_hash_siphash_2_4(
(const U8*)seed, (const U8*)in, sizeof(in)-1);
=cut
*/
#ifdef CAN64BITHASH
#define SIPROUND \
STMT_START { \
v0 += v1; v1=ROTL64(v1,13); v1 ^= v0; v0=ROTL64(v0,32); \
v2 += v3; v3=ROTL64(v3,16); v3 ^= v2; \
v0 += v3; v3=ROTL64(v3,21); v3 ^= v0; \
v2 += v1; v1=ROTL64(v1,17); v1 ^= v2; v2=ROTL64(v2,32); \
} STMT_END
#define SIPHASH_SEED_STATE(key,v0,v1,v2,v3) \
do { \
v0 = v2 = U8TO64_LE(key + 0); \
v1 = v3 = U8TO64_LE(key + 8); \
/* "somepseudorandomlygeneratedbytes" */ \
v0 ^= UINT64_C(0x736f6d6570736575); \
v1 ^= UINT64_C(0x646f72616e646f6d); \
v2 ^= UINT64_C(0x6c7967656e657261); \
v3 ^= UINT64_C(0x7465646279746573); \
} while (0)
PERL_STATIC_INLINE
void S_perl_siphash_seed_state(const unsigned char * const seed_buf, unsigned char * state_buf) {
U64 *v= (U64*) state_buf;
SIPHASH_SEED_STATE(seed_buf, v[0],v[1],v[2],v[3]);
}
#define PERL_SIPHASH_FNC(FNC,SIP_ROUNDS,SIP_FINAL_ROUNDS) \
PERL_STATIC_INLINE U64 \
FNC ## _with_state_64 \
(const unsigned char * const state, const unsigned char *in, const STRLEN inlen) \
{ \
const int left = inlen & 7; \
const U8 *end = in + inlen - left;\
\
U64 b = ( ( U64 )(inlen) ) << 56; \
U64 m; \
U64 v0 = U8TO64_LE(state); \
U64 v1 = U8TO64_LE(state+8); \
U64 v2 = U8TO64_LE(state+16); \
U64 v3 = U8TO64_LE(state+24); \
\
for ( ; in != end; in += 8 ) \
{ \
m = U8TO64_LE( in ); \
v3 ^= m; \
\
SIP_ROUNDS; \
\
v0 ^= m; \
} \
\
switch( left ) \
{ \
case 7: b |= ( ( U64 )in[ 6] ) << 48; /*FALLTHROUGH*/ \
case 6: b |= ( ( U64 )in[ 5] ) << 40; /*FALLTHROUGH*/ \
case 5: b |= ( ( U64 )in[ 4] ) << 32; /*FALLTHROUGH*/ \
case 4: b |= ( ( U64 )in[ 3] ) << 24; /*FALLTHROUGH*/ \
case 3: b |= ( ( U64 )in[ 2] ) << 16; /*FALLTHROUGH*/ \
case 2: b |= ( ( U64 )in[ 1] ) << 8; /*FALLTHROUGH*/ \
case 1: b |= ( ( U64 )in[ 0] ); break; \
case 0: break; \
} \
\
v3 ^= b; \
\
SIP_ROUNDS; \
\
v0 ^= b; \
\
v2 ^= 0xff; \
\
SIP_FINAL_ROUNDS \
\
b = v0 ^ v1 ^ v2 ^ v3; \
return b; \
} \
\
PERL_STATIC_INLINE U32 \
FNC ## _with_state \
(const unsigned char * const state, const unsigned char *in, const STRLEN inlen) \
{ \
union { \
U64 h64; \
U32 h32[2]; \
} h; \
h.h64= FNC ## _with_state_64(state,in,inlen); \
return h.h32[0] ^ h.h32[1]; \
} \
\
\
PERL_STATIC_INLINE U32 \
FNC (const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) \
{ \
U64 state[4]; \
SIPHASH_SEED_STATE(seed,state[0],state[1],state[2],state[3]); \
return FNC ## _with_state((U8*)state,in,inlen); \
} \
\
PERL_STATIC_INLINE U64 \
FNC ## _64 (const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) \
{ \
U64 state[4]; \
SIPHASH_SEED_STATE(seed,state[0],state[1],state[2],state[3]); \
return FNC ## _with_state_64((U8*)state,in,inlen); \
}
PERL_SIPHASH_FNC(
S_perl_hash_siphash_1_3
,SIPROUND;
,SIPROUND;SIPROUND;SIPROUND;
)
PERL_SIPHASH_FNC(
S_perl_hash_siphash_2_4
,SIPROUND;SIPROUND;
,SIPROUND;SIPROUND;SIPROUND;SIPROUND;
)
#endif /* defined(CAN64BITHASH) */