public virtual BigInteger CalculateAgreement(ICipherParameters pubKey)
{
MqvPublicParameters mqvPublicParameters = (MqvPublicParameters)pubKey;
ECPrivateKeyParameters staticPrivateKey = this.privParams.StaticPrivateKey;
ECPoint eCPoint = ECMqvBasicAgreement.CalculateMqvAgreement(staticPrivateKey.Parameters, staticPrivateKey, this.privParams.EphemeralPrivateKey, this.privParams.EphemeralPublicKey, mqvPublicParameters.StaticPublicKey, mqvPublicParameters.EphemeralPublicKey).Normalize();
if (eCPoint.IsInfinity)
{
throw new InvalidOperationException("Infinity is not a valid agreement value for MQV");
}
return(eCPoint.AffineXCoord.ToBigInteger());
}
private static BigInteger calculateAgreement(
AsymmetricCipherKeyPair U1,
AsymmetricCipherKeyPair U2,
AsymmetricCipherKeyPair V1,
AsymmetricCipherKeyPair V2)
{
ECMqvBasicAgreement u = new ECMqvBasicAgreement();
u.Init(new MqvPrivateParameters(
(ECPrivateKeyParameters)U1.Private,
(ECPrivateKeyParameters)U2.Private,
(ECPublicKeyParameters)U2.Public));
BigInteger ux = u.CalculateAgreement(new MqvPublicParameters(
(ECPublicKeyParameters)V1.Public,
(ECPublicKeyParameters)V2.Public));
ECMqvBasicAgreement v = new ECMqvBasicAgreement();
v.Init(new MqvPrivateParameters(
(ECPrivateKeyParameters)V1.Private,
(ECPrivateKeyParameters)V2.Private,
(ECPublicKeyParameters)V2.Public));
BigInteger vx = v.CalculateAgreement(new MqvPublicParameters(
(ECPublicKeyParameters)U1.Public,
(ECPublicKeyParameters)U2.Public));
if (ux.Equals(vx))
return ux;
return null;
}
/**
* X9.62 - 1998,<br/>
* J.3.1, Page 152, ECDSA over the field Fp<br/>
* an example with 192 bit prime
*/
private static IBigInteger CalculateAgreement(
IAsymmetricCipherKeyPair u1,
IAsymmetricCipherKeyPair u2,
IAsymmetricCipherKeyPair v1,
IAsymmetricCipherKeyPair v2)
{
var u = new ECMqvBasicAgreement();
u.Init(new MqvPrivateParameters(
(ECPrivateKeyParameters) u1.Private,
(ECPrivateKeyParameters) u2.Private,
(ECPublicKeyParameters) u2.Public));
IBigInteger ux = u.CalculateAgreement(new MqvPublicParameters(
(ECPublicKeyParameters) v1.Public,
(ECPublicKeyParameters) v2.Public));
var v = new ECMqvBasicAgreement();
v.Init(new MqvPrivateParameters(
(ECPrivateKeyParameters) v1.Private,
(ECPrivateKeyParameters) v2.Private,
(ECPublicKeyParameters) v2.Public));
IBigInteger vx = v.CalculateAgreement(new MqvPublicParameters(
(ECPublicKeyParameters) u1.Public,
(ECPublicKeyParameters) u2.Public));
if (ux.Equals(vx))
return ux;
return null;
}
