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
|
/*
* ecgen, tool for generating Elliptic curve domain parameters
* Copyright (C) 2017-2018 J08nY
*/
#include "order.h"
#include "exhaustive/arg.h"
#include "field.h"
#include "io/input.h"
#include "math/koblitz.h"
GENERATOR(order_gen_input) {
pari_sp ltop = avma;
GEN ord = input_int("order", cfg->bits);
if (gequalm1(ord)) {
avma = ltop;
return -4;
} else {
curve->order = ord;
obj_insert_shallow(curve->curve, 1, ord);
return 1;
}
}
GENERATOR(order_gen_any) {
pari_sp ltop = avma;
GEN ord = ellff_get_card(curve->curve);
if (isclone(ord)) {
curve->order = gerepilecopy(ltop, ord);
} else {
avma = ltop;
curve->order = ord;
}
return 1;
}
GENERATOR(order_gen_sea) {
pari_sp ltop = avma;
GEN order = ellsea(curve->curve, 0);
if (gequal0(order)) {
avma = ltop;
return -4;
} else {
curve->order = gerepilecopy(ltop, order);
obj_insert_shallow(curve->curve, 1, order);
return 1;
}
}
GENERATOR(order_gen_cofactor) {
HAS_ARG(args);
pari_ulong cofactor = *(pari_ulong *)args->args;
pari_sp ltop = avma;
GEN order = ellff_get_card(curve->curve);
if (!dvdii(order, utoi(cofactor))) {
avma = ltop;
return -4;
}
GEN res = diviuexact(order, cofactor);
if (!isprime(res)) {
avma = ltop;
return -4;
}
curve->order = gerepilecopy(ltop, order);
obj_insert_shallow(curve->curve, 1, curve->order);
return 1;
}
GENERATOR(order_gen_smooth) {
HAS_ARG(args);
pari_ulong smooth_bound = *(pari_ulong *)args->args;
pari_sp ltop = avma;
GEN order = ellff_get_card(curve->curve);
GEN factors = factor(order);
GEN primes = gel(factors, 1);
long uniqs = glength(primes);
for (long i = 1; i <= uniqs; ++i) {
long blen = glength(binary_zv(gel(primes, i)));
if (blen > smooth_bound) {
avma = ltop;
return -4;
}
}
curve->order = gerepilecopy(ltop, order);
obj_insert_shallow(curve->curve, 1, order);
return 1;
}
GENERATOR(order_gen_prime) {
pari_sp ltop = avma;
GEN order = ellsea(curve->curve, 1);
if (gequal0(order) || !(isprime(order))) {
avma = ltop;
return -4;
} else {
curve->order = gerepilecopy(ltop, order);
obj_insert_shallow(curve->curve, 1, curve->order);
return 1;
}
}
GENERATOR(order_gen_koblitz) {
pari_sp ltop = avma;
GEN order = koblitz_get_order(cfg->bits, itou(curve->a));
if (order) {
curve->order = gerepilecopy(ltop, order);
obj_insert_shallow(curve->curve, 1, curve->order);
} else {
GEN ord = ellff_get_card(curve->curve);
if (isclone(ord)) {
curve->order = gerepilecopy(ltop, ord);
} else {
avma = ltop;
curve->order = ord;
}
}
return 1;
}
CHECK(order_check_pohlig_hellman) {
HAS_ARG(args);
pari_sp ltop = avma;
const char *min_fact = args->args;
GEN minf = strtoi(min_fact);
GEN factors = factor(curve->order);
GEN primes = gel(factors, 1);
long len = glength(primes);
if (mpcmp(gel(primes, len), minf) <= 0) {
avma = ltop;
return -4;
} else {
avma = ltop;
return 1;
}
}
CHECK(order_check_discriminant) {
HAS_ARG(args);
if (cfg->field == FIELD_BINARY) return 1;
pari_sp ltop = avma;
const char *min_disc = args->args;
GEN mind = strtoi(min_disc);
GEN t = negi(subii(curve->order, addii(curve->field, gen_1)));
GEN tp = subii(sqri(t), mulis(curve->field, 4));
GEN D = field_elementi(core(tp));
if (abscmpii(D, mind) <= 0) {
avma = ltop;
return -4;
}
avma = ltop;
return 1;
}
|
