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
|
/* See LICENSE file for copyright and license details. */
#include "common.h"
#if defined(__clang__)
# pragma clang diagnostic push
# pragma clang diagnostic ignored "-Wconditional-uninitialized"
#elif defined(__GNUC__)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#endif
#define deft(v, dv) (have_##v ? v : (dv))
/**
* Convert a `struct libkeccak_generalised_spec` to a `struct libkeccak_spec`
*
* If you are interrested in finding errors, you should call
* `libkeccak_spec_check(output)` if this function returns zero
*
* @param spec The generalised input specifications, will be update with resolved automatic values
* @param output_spec The specification datastructure to fill in
* @return Zero if `spec` is valid, a `LIBKECCAK_GENERALISED_SPEC_ERROR_*` if an error was found
*/
int
libkeccak_degeneralise_spec(struct libkeccak_generalised_spec *restrict spec, struct libkeccak_spec *restrict output_spec)
{
long int state_size, word_size, capacity, bitrate, output;
int have_state_size = spec->state_size != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
int have_word_size = spec->word_size != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
int have_capacity = spec->capacity != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
int have_bitrate = spec->bitrate != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
int have_output = spec->output != LIBKECCAK_GENERALISED_SPEC_AUTOMATIC;
if (have_state_size) {
state_size = spec->state_size;
if (state_size <= 0)
return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_NONPOSITIVE;
if (state_size > 1600)
return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_TOO_LARGE;
if (state_size % 25)
return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_MOD_25;
}
if (have_word_size) {
word_size = spec->word_size;
if (word_size <= 0)
return LIBKECCAK_GENERALISED_SPEC_ERROR_WORD_NONPOSITIVE;
if (word_size > 64)
return LIBKECCAK_GENERALISED_SPEC_ERROR_WORD_TOO_LARGE;
if (have_state_size && state_size != word_size * 25)
return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_WORD_INCOHERENCY;
else if (!have_state_size) {
have_state_size = 1;
state_size = word_size * 25;
}
}
if (have_capacity) {
capacity = spec->capacity;
if (capacity <= 0)
return LIBKECCAK_GENERALISED_SPEC_ERROR_CAPACITY_NONPOSITIVE;
if (capacity & 7)
return LIBKECCAK_GENERALISED_SPEC_ERROR_CAPACITY_MOD_8;
}
if (have_bitrate) {
bitrate = spec->bitrate;
if (bitrate <= 0)
return LIBKECCAK_GENERALISED_SPEC_ERROR_BITRATE_NONPOSITIVE;
if (bitrate & 7)
return LIBKECCAK_GENERALISED_SPEC_ERROR_BITRATE_MOD_8;
}
if (have_output) {
output = spec->output;
if (output <= 0)
return LIBKECCAK_GENERALISED_SPEC_ERROR_OUTPUT_NONPOSITIVE;
}
if (have_bitrate + have_capacity == 2) {
if (!have_state_size) {
state_size = bitrate + capacity;
output = deft(output, capacity * 2L <= 8 ? 8 : capacity * 2L);
} else if (state_size != bitrate + capacity) {
return LIBKECCAK_GENERALISED_SPEC_ERROR_STATE_BITRATE_CAPACITY_INCONSISTENCY;
}
} else if (have_bitrate + have_capacity == 1) {
state_size = deft(state_size, 1600L);
bitrate = deft(bitrate, state_size - capacity);
capacity = deft(capacity, state_size - bitrate);
output = deft(output, capacity * 2L <= 8 ? 8 : capacity * 2L);
} else {
state_size = deft(state_size, 1600L);
output = deft(output, (state_size * 32L / 100L + 7L) & ~7L);
bitrate = 2L * output;
capacity = state_size - bitrate;
output = deft(output, bitrate / 2L <= 8 ? 8 : bitrate / 2L);
}
spec->capacity = output_spec->capacity = capacity;
spec->bitrate = output_spec->bitrate = bitrate;
spec->output = output_spec->output = output;
spec->state_size = state_size;
spec->word_size = state_size / 25;
return 0;
}
#undef deft
#if defined(__clang__)
# pragma clang diagnostic pop
#elif defined(__GNUC__)
# pragma GCC diagnostic pop
#endif
|
