public MqvPublicParameters(
ECPublicKeyParameters staticPublicKey,
ECPublicKeyParameters ephemeralPublicKey)
{
this.staticPublicKey = staticPublicKey;
this.ephemeralPublicKey = ephemeralPublicKey;
}
// The ECMQV Primitive as described in SEC-1, 3.4
private static ECPoint CalculateMqvAgreement(
ECDomainParameters parameters,
ECPrivateKeyParameters d1U,
ECPrivateKeyParameters d2U,
ECPublicKeyParameters Q2U,
ECPublicKeyParameters Q1V,
ECPublicKeyParameters Q2V)
{
BigInteger n = parameters.N;
int e = (n.BitLength + 1) / 2;
BigInteger powE = BigInteger.One.ShiftLeft(e);
ECCurve curve = parameters.Curve;
ECPoint[] points = new ECPoint[]{
// The Q2U public key is optional
ECAlgorithms.ImportPoint(curve, Q2U == null ? parameters.G.Multiply(d2U.D) : Q2U.Q),
ECAlgorithms.ImportPoint(curve, Q1V.Q),
ECAlgorithms.ImportPoint(curve, Q2V.Q)
};
curve.NormalizeAll(points);
ECPoint q2u = points[0], q1v = points[1], q2v = points[2];
BigInteger x = q2u.AffineXCoord.ToBigInteger();
BigInteger xBar = x.Mod(powE);
BigInteger Q2UBar = xBar.SetBit(e);
BigInteger s = d1U.D.Multiply(Q2UBar).Add(d2U.D).Mod(n);
BigInteger xPrime = q2v.AffineXCoord.ToBigInteger();
BigInteger xPrimeBar = xPrime.Mod(powE);
BigInteger Q2VBar = xPrimeBar.SetBit(e);
BigInteger hs = parameters.H.Multiply(s).Mod(n);
return ECAlgorithms.SumOfTwoMultiplies(
q1v, Q2VBar.Multiply(hs).Mod(n), q2v, hs);
}
internal static PublicKey Derivate(this PublicKey publicKey, byte[] cc, uint nChild, Network network, out byte[] ccChild)
{
byte[] lr = null;
byte[] l = new byte[32];
byte[] r = new byte[32];
if ((nChild >> 31) == 0)
{
var pubKey = publicKey.ToBytes();
lr = Hashes.BIP32Hash(cc, nChild, pubKey[0], pubKey.Skip(1).ToArray());
}
else
{
throw new InvalidOperationException("A public key can't derivate an hardened child");
}
Array.Copy(lr, l, 32);
Array.Copy(lr, 32, r, 0, 32);
ccChild = r;
BigInteger N = ECHelper.CURVE.N;
BigInteger parse256LL = new BigInteger(1, l);
if (parse256LL.CompareTo(N) >= 0)
throw new InvalidOperationException("You won a prize ! this should happen very rarely. Take a screenshot, and roll the dice again.");
var eq = ECHelper.Secp256k1.Curve.DecodePoint(publicKey.ToBytes());
var publicKeyParameters = new ECPublicKeyParameters("EC", eq, ECHelper.DomainParameter);
var q = ECHelper.CURVE.G.Multiply(parse256LL).Add(publicKeyParameters.Q);
if (q.IsInfinity)
throw new InvalidOperationException("You won the big prize ! this would happen only 1 in 2^127. Take a screenshot, and roll the dice again.");
var p = new BitcoinKit.BouncyCastle.Math.EC.FpPoint(ECHelper.CURVE.Curve, q.X, q.Y, true);
return new PublicKey(p.GetEncoded(), network);
}
protected bool Equals(
ECPublicKeyParameters other)
{
return q.Equals(other.q) && base.Equals(other);
}