public virtual BigInteger CalculateAgreement(
ICipherParameters pubKey)
{
ECPublicKeyParameters pub = (ECPublicKeyParameters)pubKey;
ECDomainParameters dp = privKey.Parameters;
if (!dp.Equals(pub.Parameters))
{
throw new InvalidOperationException("ECDHC public key has wrong domain parameters");
}
BigInteger hd = dp.H.Multiply(privKey.D).Mod(dp.N);
// Always perform calculations on the exact curve specified by our private key's parameters
ECPoint pubPoint = ECAlgorithms.CleanPoint(dp.Curve, pub.Q);
if (pubPoint.IsInfinity)
{
throw new InvalidOperationException("Infinity is not a valid public key for ECDHC");
}
ECPoint P = pubPoint.Multiply(hd).Normalize();
if (P.IsInfinity)
{
throw new InvalidOperationException("Infinity is not a valid agreement value for ECDHC");
}
return(P.AffineXCoord.ToBigInteger());
}
protected bool Equals(ECKeyParameters other)
{
if (parameters.Equals(other.parameters))
{
return(Equals((AsymmetricKeyParameter)other));
}
return(false);
}
private ECPoint CalculatePoint(ECPublicKeyParameters pubKeyParams)
{
ECDomainParameters dp = keyParam.Parameters;
if (!dp.Equals(pubKeyParams.Parameters))
{
throw new InvalidOperationException(
"ECDH public key has wrong domain parameters"
);
}
BigInteger d = keyParam.D;
ECPoint q = dp.Curve.DecodePoint(pubKeyParams.Q.GetEncoded(true));
if (q.IsInfinity)
{
throw new InvalidOperationException(
"Infinity is not a valid public key for ECDH"
);
}
BigInteger h = dp.H;
if (!h.Equals(BigInteger.One))
{
d = dp.H.ModInverse(dp.N).Multiply(d).Mod(dp.N);
q = ECAlgorithms.ReferenceMultiply(q, h);
}
ECPoint p = q.Multiply(d).Normalize();
if (p.IsInfinity)
{
throw new InvalidOperationException(
"Infinity is not a valid agreement value for ECDH"
);
}
return(p);
}
public virtual BigInteger CalculateAgreement(
ICipherParameters pubKey)
{
ECPublicKeyParameters pub = (ECPublicKeyParameters)pubKey;
ECDomainParameters parameters = pub.Parameters;
if (!parameters.Equals(privKey.Parameters))
{
throw new InvalidOperationException("ECDHC public key has wrong domain parameters");
}
BigInteger hd = parameters.H.Multiply(privKey.D).Mod(parameters.N);
ECPoint P = pub.Q.Multiply(hd).Normalize();
if (P.IsInfinity)
{
throw new InvalidOperationException("Infinity is not a valid agreement value for ECDHC");
}
return(P.AffineXCoord.ToBigInteger());
}
public virtual BigInteger CalculateAgreement(
ICipherParameters pubKey)
{
MqvPublicParameters pubParams = (MqvPublicParameters)pubKey;
ECPrivateKeyParameters staticPrivateKey = privParams.StaticPrivateKey;
ECDomainParameters parameters = staticPrivateKey.Parameters;
if (!parameters.Equals(pubParams.StaticPublicKey.Parameters))
{
throw new InvalidOperationException("ECMQV public key components have wrong domain parameters");
}
ECPoint agreement = CalculateMqvAgreement(parameters, staticPrivateKey,
privParams.EphemeralPrivateKey, privParams.EphemeralPublicKey,
pubParams.StaticPublicKey, pubParams.EphemeralPublicKey).Normalize();
if (agreement.IsInfinity)
{
throw new InvalidOperationException("Infinity is not a valid agreement value for MQV");
}
return(agreement.AffineXCoord.ToBigInteger());
}
public static bool AreOnSameCurve(ECDomainParameters a, ECDomainParameters b)
{
return(a != null && a.Equals(b));
}
public static bool AreOnSameCurve(ECDomainParameters a, ECDomainParameters b) => ((a != null) && a.Equals(b));
