private void BuildKeys()
{
//Make a call to Generate_Primes.
BigInteger P = new BigInteger(m_RSAParams.P);
BigInteger Q = new BigInteger(m_RSAParams.Q);
//Exponent. This needs to be a number such that the
//GCD of the Exponent and Phi is 1. The larger the exp.
//the more secure, but it increases encryption time.
BigInteger E = new BigInteger(m_RSAParams.E);
BigInteger N = new BigInteger(0);
//Public and Private Key Part (Modulus)
BigInteger D = new BigInteger(0);
//Private Key Part
BigInteger DP = new BigInteger(0);
BigInteger DQ = new BigInteger(0);
BigInteger IQ = new BigInteger(0);
BigInteger Phi = new BigInteger(0);
//Phi
//Make sure P is greater than Q, swap if less.
if (P < Q)
{
BigInteger biTmp = P;
P = Q;
Q = biTmp;
biTmp = null;
m_RSAParams.P = P.getBytesRaw();
m_RSAParams.Q = Q.getBytesRaw();
}
//Calculate the modulus
N = P * Q;
m_RSAParams.N = N.getBytesRaw();
//Calculate Phi
Phi = (P - 1) * (Q - 1);
m_RSAParams.Phi = Phi.getBytesRaw();
//Make sure our Exponent will work, or choose a larger one.
while (Phi.gcd(E) > 1)
{
//If the GCD is greater than 1 iterate the Exponent
E = E + 2;
//Also make sure the Exponent is prime.
while (!E.isProbablePrime())
{
E = E + 2;
}
}
//Make sure the params contain the updated E value
m_RSAParams.E = E.getBytesRaw();
//Calculate the private exponent D.
D = E.modInverse(Phi);
m_RSAParams.D = D.getBytesRaw();
//Calculate DP
DP = E.modInverse(P - 1);
m_RSAParams.DP = DP.getBytesRaw();
//Calculate DQ
DQ = E.modInverse(Q - 1);
m_RSAParams.DQ = DQ.getBytesRaw();
//Calculate InverseQ
IQ = Q.modInverse(P);
m_RSAParams.IQ = IQ.getBytesRaw();
m_KeyLoaded = true;
m_isBusy = false;
OnKeysGenerated(this);
}
//***********************************************************************
// Generates a positive BigInteger that is probably prime.
// Overloaded to use the isProbablePrime method with no confidence value
//***********************************************************************
internal static BigInteger genPseudoPrime(int bits, Random rand)
{
BigInteger result = new BigInteger();
bool done = false;
while (!done)
{
result.genRandomBits(bits, rand);
result.data[0] |= 0x01; // make it odd
// prime test
done = result.isProbablePrime();
}
return result;
}