You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
64 lines
1.3 KiB
64 lines
1.3 KiB
#include "fe.h"
|
|
|
|
/*
|
|
Replace (f,g) with (g,g) if b == 1;
|
|
replace (f,g) with (f,g) if b == 0.
|
|
|
|
Preconditions: b in {0,1}.
|
|
*/
|
|
|
|
void fe_cmov(fe f,const fe g,unsigned int b)
|
|
{
|
|
crypto_int32 f0 = f[0];
|
|
crypto_int32 f1 = f[1];
|
|
crypto_int32 f2 = f[2];
|
|
crypto_int32 f3 = f[3];
|
|
crypto_int32 f4 = f[4];
|
|
crypto_int32 f5 = f[5];
|
|
crypto_int32 f6 = f[6];
|
|
crypto_int32 f7 = f[7];
|
|
crypto_int32 f8 = f[8];
|
|
crypto_int32 f9 = f[9];
|
|
crypto_int32 g0 = g[0];
|
|
crypto_int32 g1 = g[1];
|
|
crypto_int32 g2 = g[2];
|
|
crypto_int32 g3 = g[3];
|
|
crypto_int32 g4 = g[4];
|
|
crypto_int32 g5 = g[5];
|
|
crypto_int32 g6 = g[6];
|
|
crypto_int32 g7 = g[7];
|
|
crypto_int32 g8 = g[8];
|
|
crypto_int32 g9 = g[9];
|
|
crypto_int32 x0 = f0 ^ g0;
|
|
crypto_int32 x1 = f1 ^ g1;
|
|
crypto_int32 x2 = f2 ^ g2;
|
|
crypto_int32 x3 = f3 ^ g3;
|
|
crypto_int32 x4 = f4 ^ g4;
|
|
crypto_int32 x5 = f5 ^ g5;
|
|
crypto_int32 x6 = f6 ^ g6;
|
|
crypto_int32 x7 = f7 ^ g7;
|
|
crypto_int32 x8 = f8 ^ g8;
|
|
crypto_int32 x9 = f9 ^ g9;
|
|
b = -b;
|
|
x0 &= b;
|
|
x1 &= b;
|
|
x2 &= b;
|
|
x3 &= b;
|
|
x4 &= b;
|
|
x5 &= b;
|
|
x6 &= b;
|
|
x7 &= b;
|
|
x8 &= b;
|
|
x9 &= b;
|
|
f[0] = f0 ^ x0;
|
|
f[1] = f1 ^ x1;
|
|
f[2] = f2 ^ x2;
|
|
f[3] = f3 ^ x3;
|
|
f[4] = f4 ^ x4;
|
|
f[5] = f5 ^ x5;
|
|
f[6] = f6 ^ x6;
|
|
f[7] = f7 ^ x7;
|
|
f[8] = f8 ^ x8;
|
|
f[9] = f9 ^ x9;
|
|
}
|