public RSAConfig(byte[] modulus, byte[] exponent, int modulusSize)
{
_ModulusOctets = modulusSize / 8;
_E = RSAHelper.OS2IP(exponent, false);
_N = RSAHelper.OS2IP(modulus, false);
_Has_PUBLIC_Info = true;
}
public byte[] CrunchRSA(byte[] plainText, bool usePrivate)
{
if (usePrivate && (!_rsaConfig.Has_PRIVATE_Info))
{
throw new CryptographicException("No private key");
}
if ((usePrivate == false) && (!_rsaConfig.Has_PUBLIC_Info))
{
throw new CryptographicException("No public key");
}
BigInteger e;
if (usePrivate)
{
e = _rsaConfig.D;
}
else
{
e = _rsaConfig.E;
}
var PT = RSAHelper.OS2IP(plainText, false);
var M = BigInteger.ModPow(PT, e, _rsaConfig.N);
return(M.Sign == -1 ?
RSAHelper.I2OSP(M + _rsaConfig.N, _rsaConfig.OctetsInModulus, false) :
RSAHelper.I2OSP(M, _rsaConfig.OctetsInModulus, false));
}
public RSAConfig(byte[] modulus, byte[] exponent, byte[] d, int modulusSize)
{
// _rsaConfig;
_ModulusOctets = modulusSize / 8;
_E = RSAHelper.OS2IP(exponent, false);
_N = RSAHelper.OS2IP(modulus, false);
_D = RSAHelper.OS2IP(d, false);
_Has_PUBLIC_Info = true;
_Has_PRIVATE_Info = true;
}
public RSAConfig(byte[] modulus, byte[] exponent, byte[] d, byte[] P, byte[] Q, byte[] DP, byte[] DQ, byte[] inverseQ, int modulusSize)
{
_ModulusOctets = modulusSize / 8;
_E = RSAHelper.OS2IP(exponent, false);
_N = RSAHelper.OS2IP(modulus, false);
_D = RSAHelper.OS2IP(d, false);
_P = RSAHelper.OS2IP(P, false);
_Q = RSAHelper.OS2IP(Q, false);
_DP = RSAHelper.OS2IP(DP, false);
_DQ = RSAHelper.OS2IP(DQ, false);
_InverseQ = RSAHelper.OS2IP(inverseQ, false);
_Has_CRT_Info = true;
_Has_PUBLIC_Info = true;
_Has_PRIVATE_Info = true;
}
public RSAConfig(RSAParameters rsaParams, int ModulusSize)
{
_ModulusOctets = ModulusSize / 8;
_E = RSAHelper.OS2IP(rsaParams.Exponent, false);
_D = RSAHelper.OS2IP(rsaParams.D, false);
_N = RSAHelper.OS2IP(rsaParams.Modulus, false);
_P = RSAHelper.OS2IP(rsaParams.P, false);
_Q = RSAHelper.OS2IP(rsaParams.Q, false);
_DP = RSAHelper.OS2IP(rsaParams.DP, false);
_DQ = RSAHelper.OS2IP(rsaParams.DQ, false);
_InverseQ = RSAHelper.OS2IP(rsaParams.InverseQ, false);
_Has_CRT_Info = true;
_Has_PUBLIC_Info = true;
_Has_PRIVATE_Info = true;
}
public byte[] PrivateDecryptFast(byte[] data)
{
if (!_rsaConfig.Has_PRIVATE_Info || !_rsaConfig.HasCRTInfo)
{
throw new CryptographicException("No private key");
}
else
{
var c = RSAHelper.OS2IP(data, false);
var m1 = BigInteger.ModPow(c, _rsaConfig.DP, _rsaConfig.P);
var m2 = BigInteger.ModPow(c, _rsaConfig.DQ, _rsaConfig.Q);
var h = ((m1 - m2) * _rsaConfig.InverseQ) % _rsaConfig.P;
var m = (m2 + (_rsaConfig.Q * h));
return(m.Sign == -1 ?
RSAHelper.I2OSP(m + _rsaConfig.N, _rsaConfig.OctetsInModulus, false)
: RSAHelper.I2OSP(m, _rsaConfig.OctetsInModulus, false));
}
}
