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
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
|
/**
* libkeccak – Keccak-family hashing library
*
* Copyright © 2014, 2015 Mattias Andrée (maandree@member.fsf.org)
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LIBKECCAK_MAC_HMAC_H
#define LIBKECCAK_MAC_HMAC_H 1
/* The Keccak hash-function, that was selected by NIST as the SHA-3 competition winner,
* doesn't need this nested approach and can be used to generate a MAC by simply prepending
* the key to the message. [http://keccak.noekeon.org]
*/
#include "../spec.h"
#include "../state.h"
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
/**
* Datastructure that describes the state of an HMAC-hashing process
*/
typedef struct libkeccak_hmac_state
{
/**
* The key right-padded and XOR:ed with the outer pad
*/
char* restrict key_opad;
/**
* The key right-padded and XOR:ed with the inner pad
*/
char* restrict key_ipad;
/* Not marshalled, implicitly unmarshalled using `key_opad`. */
/* Shares allocation with `key_opad`, do not `free`. */
/**
* The length of key, but at least the input block size, in bits
*/
size_t key_length;
/**
* The state of the underlaying hash-algorithm
*/
libkeccak_state_t sponge;
/**
* Buffer used to temporarily store bit shift message if
* `.key_length` is not zero modulus 8
*/
char* restrict buffer;
/**
* The allocation size of `.buffer`
*/
size_t buffer_size;
/**
* Part of feed key, message or digest that have not been passed yet
*/
char leftover;
char __pad[sizeof(void*) / sizeof(char) - 1];
} libkeccak_hmac_state_t;
/**
* Change to HMAC-hashing key on the state
*
* @param state The state that should be reset
* @param key The new key
* @param key_length The length of key, in bits
* @return Zero on success, -1 on error
*/
__attribute__((nonnull(1), unused))
int libkeccak_hmac_set_key(libkeccak_hmac_state_t* restrict state, const char* restrict key, size_t key_length);
/**
* Initialise an HMAC hashing-state according to hashing specifications
*
* @param state The state that should be initialised
* @param spec The specifications for the state
* @param key The key
* @param key_length The length of key, in bits
* @return Zero on success, -1 on error
*/
static inline __attribute__((nonnull))
int libkeccak_hmac_initialise(libkeccak_hmac_state_t* restrict state, const libkeccak_spec_t* restrict spec,
const char* restrict key, size_t key_length)
{
int saved_errno;
if (libkeccak_state_initialise(&(state->sponge), spec) < 0)
return -1;
if (libkeccak_hmac_set_key(state, key, key_length) < 0)
return saved_errno = errno, libkeccak_state_destroy(&(state->sponge)), errno = saved_errno, -1;
state->leftover = 0;
state->buffer = NULL;
state->buffer_size = 0;
return 0;
}
/**
* Wrapper for `libkeccak_hmac_initialise` that also allocates the states
*
* @param spec The specifications for the state
* @param key The key
* @param key_length The length of key, in bits
* @return The state, `NULL` on error
*/
static inline __attribute__((nonnull, unused, warn_unused_result, malloc))
libkeccak_hmac_state_t* libkeccak_hmac_create(const libkeccak_spec_t* restrict spec,
const char* restrict key, size_t key_length)
{
libkeccak_hmac_state_t* restrict state = malloc(sizeof(libkeccak_hmac_state_t));
int saved_errno;
if ((state == NULL) || libkeccak_hmac_initialise(state, spec, key, key_length))
return saved_errno = errno, free(state), errno = saved_errno, NULL;
return state;
}
/**
* Reset an HMAC-hashing state according to hashing specifications,
* you can choose whether to change the key
*
* @param state The state that should be reset
* @param key The new key, `NULL` to keep the old key
* @param key_length The length of key, in bits, ignored if `key == NULL`
* @return Zero on success, -1 on error
*/
static inline __attribute__((nonnull(1), unused))
int libkeccak_hmac_reset(libkeccak_hmac_state_t* restrict state, const char* restrict key, size_t key_length)
{
libkeccak_state_reset(&(state->sponge));
return key != NULL ? libkeccak_hmac_set_key(state, key, key_length) : 0;
}
/**
* Wipe sensitive data wihout freeing any data
*
* @param state The state that should be wipe
*/
__attribute__((nonnull, nothrow, optimize("-O0")))
void libkeccak_hmac_wipe(volatile libkeccak_hmac_state_t* restrict state);
/**
* Release resources allocation for an HMAC hashing-state without wiping sensitive data
*
* @param state The state that should be destroyed
*/
static inline
void libkeccak_hmac_fast_destroy(libkeccak_hmac_state_t* restrict state)
{
if (state == NULL)
return;
free(state->key_opad);
state->key_opad = NULL;
state->key_ipad = NULL;
state->key_length = 0;
free(state->buffer);
state->buffer = NULL;
state->buffer_size = 0;
}
/**
* Release resources allocation for an HMAC hasing-state and wipe sensitive data
*
* @param state The state that should be destroyed
*/
static inline __attribute__((unused, optimize("-O0")))
void libkeccak_hmac_destroy(volatile libkeccak_hmac_state_t* restrict state)
{
if (state == NULL)
return;
libkeccak_hmac_wipe(state);
free(state->key_opad);
state->key_opad = NULL;
state->key_ipad = NULL;
state->key_length = 0;
state->leftover = 0;
free(state->buffer);
state->buffer = NULL;
state->buffer_size = 0;
}
/**
* Wrapper for `libkeccak_fast_destroy` that also frees the allocation of the state
*
* @param state The state that should be freed
*/
static inline __attribute__((unused))
void libkeccak_hmac_fast_free(libkeccak_hmac_state_t* restrict state)
{
libkeccak_hmac_fast_destroy(state);
free(state);
}
/**
* Wrapper for `libkeccak_hmac_destroy` that also frees the allocation of the state
*
* @param state The state that should be freed
*/
static inline __attribute__((unused, optimize("-O0")))
void libkeccak_hmac_free(volatile libkeccak_hmac_state_t* restrict state)
{
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-qual"
libkeccak_hmac_destroy(state);
free((libkeccak_hmac_state_t*)state);
# pragma GCC diagnostic pop
}
/**
* Make a copy of an HMAC hashing-state
*
* @param dest The slot for the duplicate, must not be initialised (memory leak otherwise)
* @param src The state to duplicate
* @return Zero on success, -1 on error
*/
__attribute__((nonnull))
int libkeccak_hmac_copy(libkeccak_hmac_state_t* restrict dest, const libkeccak_hmac_state_t* restrict src);
/**
* A wrapper for `libkeccak_hmac_copy` that also allocates the duplicate
*
* @param src The state to duplicate
* @return The duplicate, `NULL` on error
*/
static inline __attribute__((nonnull, unused, warn_unused_result, malloc))
libkeccak_hmac_state_t* libkeccak_hmac_duplicate(const libkeccak_hmac_state_t* restrict src)
{
libkeccak_hmac_state_t* restrict dest = malloc(sizeof(libkeccak_hmac_state_t));
int saved_errno;
if ((dest == NULL) || libkeccak_hmac_copy(dest, src))
return saved_errno = errno, libkeccak_hmac_free(dest), errno = saved_errno, NULL;
return dest;
}
/**
* Calculates the allocation size required for the second argument
* of `libkeccak_hmac_marshal` (`char* restrict data)`)
*
* @param state The state as it will be marshalled by a subsequent call to `libkeccak_hamc_marshal`
* @return The allocation size needed for the buffer to which the state will be marshalled
*/
static inline __attribute__((nonnull, nothrow, unused, warn_unused_result, pure))
size_t libkeccak_hmac_marshal_size(const libkeccak_hmac_state_t* restrict state)
{
return libkeccak_state_marshal_size(&(state->sponge)) + sizeof(size_t) +
((state->key_length + 7) >> 3) + 2 * sizeof(char);
}
/**
* Marshal a `libkeccak_hmac_state_t` into a buffer
*
* @param state The state to marshal
* @param data The output buffer
* @return The number of bytes stored to `data`
*/
static inline __attribute__((nonnull, nothrow))
size_t libkeccak_hmac_marshal(const libkeccak_hmac_state_t* restrict state, char* restrict data)
{
size_t written = libkeccak_state_marshal(&(state->sponge), data);
data += written / sizeof(char);
*(size_t*)data = state->key_length;
data += sizeof(size_t) / sizeof(char);
memcpy(data, state->key_opad, (state->key_length + 7) >> 3);
data += ((state->key_length + 7) >> 3) / sizeof(char);
data[0] = (char)(state->key_ipad != NULL);
data[1] = state->leftover;
return written + sizeof(size_t) + ((state->key_length + 7) >> 3) + 2 * sizeof(char);
}
/**
* Unmarshal a `libkeccak_hmac_state_t` from a buffer
*
* @param state The slot for the unmarshalled state, must not be initialised (memory leak otherwise)
* @param data The input buffer
* @return The number of bytes read from `data`, 0 on error
*/
__attribute__((nonnull))
size_t libkeccak_hmac_unmarshal(libkeccak_hmac_state_t* restrict state, const char* restrict data);
/**
* Gets the number of bytes the `libkeccak_hmac_state_t` stored
* at the beginning of `data` occupies
*
* @param data The data buffer
* @return The byte size of the stored state
*/
static inline __attribute__((nonnull, nothrow, warn_unused_result, pure))
size_t libkeccak_hmac_unmarshal_skip(const char* restrict data)
{
size_t skip = libkeccak_state_unmarshal_skip(data);
data += skip / sizeof(char);
return skip + sizeof(size_t) + *(const size_t*)data + 2 * sizeof(char);
}
/**
* Absorb more, or the first part, of the message
* without wiping sensitive data when possible
*
* @param state The hashing state
* @param msg The partial message
* @param msglen The length of the partial message, in bytes
* @return Zero on success, -1 on error
*/
__attribute__((nonnull(1)))
int libkeccak_hmac_fast_update(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen);
/**
* Absorb more, or the first part, of the message
* and wipe sensitive data when possible
*
* @param state The hashing state
* @param msg The partial message
* @param msglen The length of the partial message, in bytes
* @return Zero on success, -1 on error
*/
__attribute__((nonnull(1)))
int libkeccak_hmac_update(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen);
/**
* Absorb the last part of the message and fetch the hash
* without wiping sensitive data when possible
*
* You may use `&(state->sponge)` for continued squeezing
*
* @param state The hashing state
* @param msg The rest of the message, may be `NULL`, may be modified
* @param msglen The length of the partial message
* @param bits The number of bits at the end of the message not covered by `msglen`
* @param suffix The suffix concatenate to the message, only '1':s and '0':s, and NUL-termination
* @param hashsum Output parameter for the hashsum, may be `NULL`
* @return Zero on success, -1 on error
*/
__attribute__((nonnull(1)))
int libkeccak_hmac_fast_digest(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen,
size_t bits, const char* restrict suffix, char* restrict hashsum);
/**
* Absorb the last part of the message and fetch the hash
* and wipe sensitive data when possible
*
* You may use `&(state->sponge)` for continued squeezing
*
* @param state The hashing state
* @param msg The rest of the message, may be `NULL`, may be modified
* @param msglen The length of the partial message
* @param bits The number of bits at the end of the message not covered by `msglen`
* @param suffix The suffix concatenate to the message, only '1':s and '0':s, and NUL-termination
* @param hashsum Output parameter for the hashsum, may be `NULL`
* @return Zero on success, -1 on error
*/
__attribute__((nonnull(1)))
int libkeccak_hmac_digest(libkeccak_hmac_state_t* restrict state, const char* restrict msg, size_t msglen,
size_t bits, const char* restrict suffix, char* restrict hashsum);
#endif
|