public RSA(BigInt p, BigInt q)
{
if (p.Sign < 0 || q.Sign < 0)
{
throw new Exception("Numbers must be positive");
}
if (!BigInt.IsItSimple(p) || !BigInt.IsItSimple(q))
{
throw new Exception("Numbers must be simple");
}
n = p * q;
var fi = (p - new BigInt("1")) * (q - new BigInt("1"));
e = fi - new BigInt("1");
while (!(BigInt.IsItSimple(e) && BigInt.Gcd(e, fi, out var x, out var y) == new BigInt("1")))
{
e -= new BigInt("2");
}
d = BigInt.GetInverseElementModulo(e, fi);
}