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
|
/*
20140918
Jan Mojzis
Public domain.
*/
#include "fe.h"
/*
o = 0
*/
void fe_0(fe o) {
long long i;
for (i = 0; i < 8; ++i) o[i] = 0;
}
/*
o = 1
*/
void fe_1(fe o) {
fe_0(o);
o[0] = 1;
}
/*
o = x
*/
void fe_copy(fe o, const fe x) {
long long i;
for (i = 0; i < 8; ++i) o[i] = x[i];
}
/*
if (b) swap(f, g)
*/
void fe_cswap(fe f, fe g, crypto_uint32 b) {
long long i;
fe t;
b = -b;
for (i = 0; i < 8; ++i) t[i] = b & (f[i] ^ g[i]);
for (i = 0; i < 8; ++i) f[i] ^= t[i];
for (i = 0; i < 8; ++i) g[i] ^= t[i];
fe_0(t);
}
/*
if (b) f = g
*/
void fe_cmov(fe f, const fe g, crypto_uint32 b) {
long long i;
fe t;
b = -b;
for (i = 0; i < 8; ++i) t[i] = b & (f[i] ^ g[i]);
for (i = 0; i < 8; ++i) f[i] ^= t[i];
fe_0(t);
}
/*
o = a * b
*/
/*
Implementation note: fe_mul_() is unrolled version of:
void fe_mul_(fel o, const fe a, const fe b) {
crypto_uint64 u;
long long i, j;
for (i = 0; i < 16; ++i) o[i] = 0;
for (i = 0; i < 8; ++i) for (j = 0; j < 8; ++j) {
u = (crypto_uint64)a[i] * (crypto_uint64)b[j];
o[i + j ] += u & 0xffffffff;
o[i + j + 1] += u >> 32;
}
}
*/
#define M(i, j) u = (crypto_uint64)a[i] * (crypto_uint64)b[j]; \
o[i + j ] += u & 0xffffffff; \
o[i + j + 1] += u >> 32;
void fe_mul_(fel o, const fe a, const fe b) {
crypto_uint64 u;
long long i;
for (i = 0; i < 16; ++i) o[i] = 0;
M(0, 0); M(0, 1); M(0, 2); M(0, 3); M(0, 4); M(0, 5); M(0, 6); M(0, 7);
M(1, 0); M(1, 1); M(1, 2); M(1, 3); M(1, 4); M(1, 5); M(1, 6); M(1, 7);
M(2, 0); M(2, 1); M(2, 2); M(2, 3); M(2, 4); M(2, 5); M(2, 6); M(2, 7);
M(3, 0); M(3, 1); M(3, 2); M(3, 3); M(3, 4); M(3, 5); M(3, 6); M(3, 7);
M(4, 0); M(4, 1); M(4, 2); M(4, 3); M(4, 4); M(4, 5); M(4, 6); M(4, 7);
M(5, 0); M(5, 1); M(5, 2); M(5, 3); M(5, 4); M(5, 5); M(5, 6); M(5, 7);
M(6, 0); M(6, 1); M(6, 2); M(6, 3); M(6, 4); M(6, 5); M(6, 6); M(6, 7);
M(7, 0); M(7, 1); M(7, 2); M(7, 3); M(7, 4); M(7, 5); M(7, 6); M(7, 7);
}
/*
o = x ^ 2
*/
/*
Implementation note: fe_sq_() is unrolled version of:
void fe_sq_(fel o, const fe a) {
crypto_uint64 u;
long long i, j;
for (i = 0; i < 16; ++i) o[i] = 0;
for (i = 0; i < 8; ++i) for (j = i + 1; j < 8; ++j) {
u = (crypto_uint64)a[i] * (crypto_uint64)a[j];
o[i + j ] += 2 * (u & 0xffffffff);
o[i + j + 1] += 2 * (u >> 32);
}
for (i = 0; i < 8; ++i) {
u = (crypto_uint64)a[i] * (crypto_uint64)a[i];
o[2 * i ] += (u & 0xffffffff);
o[2 * i + 1] += (u >> 32);
}
}
*/
#define M2(i, j) u = (crypto_uint64)a[i] * (crypto_uint64)a[j]; \
o[i + j ] += 2 * (u & 0xffffffff); \
o[i + j + 1] += 2 * (u >> 32);
#define SQ(i) u = (crypto_uint64)a[i] * (crypto_uint64)a[i]; \
o[2 * i ] += (u & 0xffffffff); \
o[2 * i + 1] += (u >> 32)
void fe_sq_(fel o, const fe a) {
crypto_uint64 u;
long long i;
for (i = 0; i < 16; ++i) o[i] = 0;
M2(0, 1); M2(0, 2); M2(0, 3); M2(0, 4); M2(0, 5); M2(0, 6); M2(0, 7);
M2(1, 2); M2(1, 3); M2(1, 4); M2(1, 5); M2(1, 6); M2(1, 7);
M2(2, 3); M2(2, 4); M2(2, 5); M2(2, 6); M2(2, 7);
M2(3, 4); M2(3, 5); M2(3, 6); M2(3, 7);
M2(4, 5); M2(4, 6); M2(4, 7);
M2(5, 6); M2(5, 7);
M2(6, 7);
SQ(0); SQ(1); SQ(2); SQ(3); SQ(4); SQ(5); SQ(6); SQ(7);
}
/*
if (p < r) r -= p
*/
void fe_reducesmall(fe r, const fe p, const crypto_uint64 carry) {
crypto_uint64 pb = 0, b;
long long i;
fe t;
for (i = 0; i < 8; ++i) {
pb += (crypto_uint64)p[i];
b = (crypto_uint64)r[i] - pb; b >>= 63;
t[i] = (crypto_uint64)r[i] - pb + (b << 32);
pb = b;
}
b = carry - pb; b >>= 63;
b -= 1;
for (i = 0; i < 8; ++i) r[i] ^= b & (r[i] ^ t[i]);
fe_0(t);
}
/*
if (f == 0 && g == 0 && h == 0) return 1;
else return 0;
*/
int fe_iszero3(const fe f, const fe g, const fe h) {
long long i;
crypto_uint32 x = 0;
for (i = 0; i < 8; ++i) x |= f[i];
for (i = 0; i < 8; ++i) x |= g[i];
for (i = 0; i < 8; ++i) x |= h[i];
return (4294967296ULL - (crypto_uint64)x) >> 32;
}
/*
if (f == 0 && g == 0) return 1;
else return 0;
*/
int fe_iszero2(const fe f, const fe g) {
long long i;
crypto_uint32 x = 0;
for (i = 0; i < 8; ++i) x |= f[i];
for (i = 0; i < 8; ++i) x |= g[i];
return (4294967296ULL - (crypto_uint64)x) >> 32;
}
|
