TEST(Integer, OpenModInverse)
{
for(int i=0; i<10; i++) {
Integer p = Integer::GetRandomInteger(1024, true);
Integer a = Integer::GetRandomInteger(0, p);
Integer na = a * Integer(-1);
ASSERT_EQ(na, a - (2*a));
ASSERT_EQ((a-p)%p, a);
ASSERT_EQ((a-(40*p))%p, a);
Integer inv = a.ModInverse(p);
Integer out = (a*inv)%p;
ASSERT_TRUE(a > 0);
ASSERT_TRUE(p > a);
qDebug() << "a" << a.GetByteArray().toHex();
qDebug() << "p" << p.GetByteArray().toHex();
qDebug() << "out" << out.GetByteArray().toHex();
ASSERT_EQ(Integer(1), out);
}
}
TEST(Integer, ModInverse)
{
Integer mod = Integer::GetRandomInteger(1024);
// mod should be prime to ensure (higher likelihood of) multiplicative inverse
mod = Integer::GetRandomInteger(1024, mod, true);
Integer val = Integer::GetRandomInteger(1024, mod);
Integer mi = val.ModInverse(mod);
Integer result = (val * mi) % mod;
qDebug() << result.ToString() << (val < mod) << (mi < mod);
EXPECT_EQ(result, 1);
}
TEST(Integer, CppModInverse)
{
for(int i=0; i<10; i++) {
Integer p = Integer::GetRandomInteger(1024, true);
Integer a = Integer::GetRandomInteger(0, p);
Integer inv = a.ModInverse(p);
Integer out = (a*inv)%p;
ASSERT_TRUE(a > 0);
ASSERT_TRUE(p > a);
qDebug() << "a" << a.GetByteArray().toHex();
qDebug() << "p" << p.GetByteArray().toHex();
qDebug() << "out" << out.GetByteArray().toHex();
ASSERT_EQ(Integer(1), out);
}
}
