public byte[] Encode()
{
var asnEncoder = new Asn1BerEncodeBuffer();
var keyTransport = new GostR3410KeyTransport();
try
{
keyTransport.SessionEncryptedKey = new Gost2814789EncryptedKey
{
EncryptedKey = new Gost2814789Key(SessionEncryptedKey.EncryptedKey),
MacKey = new Gost2814789Mac(SessionEncryptedKey.Mac)
};
keyTransport.TransportParameters = new GostR3410TransportParameters
{
Ukm = new Asn1OctetString(SessionEncryptedKey.Ukm),
EncryptionParamSet = CreateEncryptionParamSet(SessionEncryptedKey.EncryptionParamSet),
EphemeralPublicKey = EncodePublicKey(TransportParameters)
};
keyTransport.Encode(asnEncoder);
}
catch (Exception exception)
{
throw ExceptionUtility.CryptographicException(exception, Resources.Asn1EncodeError, typeof(GostR3410KeyTransport).FullName);
}
return asnEncoder.MsgCopy;
}
public void Decode(byte[] data)
{
if (data == null)
{
throw ExceptionUtility.ArgumentNull("data");
}
try
{
var asnDecoder = new Asn1BerDecodeBuffer(data);
var keyTransport = new GostR3410KeyTransport();
keyTransport.Decode(asnDecoder);
SessionEncryptedKey = DecodeSessionKey(keyTransport);
TransportParameters = DecodePublicKey(keyTransport);
}
catch (Exception exception)
{
throw ExceptionUtility.CryptographicException(exception, Resources.Asn1DecodeError, typeof(GostR3410KeyTransport).FullName);
}
}
private static GostKeyExchangeParameters DecodePublicKey(GostR3410KeyTransport keyTransport)
{
var publicKeyInfo = keyTransport.TransportParameters.EphemeralPublicKey;
var publicKeyAlgOid = Asn1ObjectIdentifier.ToOidString(publicKeyInfo.Algorithm.Algorithm);
if (!publicKeyAlgOid.Equals(GostR34102001Constants.IdGostR34102001String))
{
throw ExceptionUtility.CryptographicException(Resources.Asn1DecodeAlg, publicKeyAlgOid);
}
var choice = publicKeyInfo.Algorithm.Parameters as Asn1Choice;
if (choice == null)
{
throw ExceptionUtility.CryptographicException(Resources.Asn1DecodeAlgorithmParameters);
}
var publicKeyParams = choice.GetElement() as GostR34102001PublicKeyParameters;
if (publicKeyParams == null)
{
throw ExceptionUtility.CryptographicException(Resources.Asn1DecodeAlgorithmParameters);
}
var asnDecoder = new Asn1BerDecodeBuffer(publicKeyInfo.SubjectPublicKey.Value);
var publicKey = new Asn1OctetString();
publicKey.Decode(asnDecoder);
return new GostKeyExchangeParameters
{
DigestParamSet = Asn1ObjectIdentifier.ToOidString(publicKeyParams.DigestParamSet),
PublicKeyParamSet = Asn1ObjectIdentifier.ToOidString(publicKeyParams.PublicKeyParamSet),
EncryptionParamSet = Asn1ObjectIdentifier.ToOidString(publicKeyParams.EncryptionParamSet),
PublicKey = publicKey.Value,
PrivateKey = null
};
}
private static GostKeyExchangeInfo DecodeSessionKey(GostR3410KeyTransport keyTransport)
{
return new GostKeyExchangeInfo
{
EncryptionParamSet = Asn1ObjectIdentifier.ToOidString(keyTransport.TransportParameters.EncryptionParamSet),
EncryptedKey = keyTransport.SessionEncryptedKey.EncryptedKey.Value,
Mac = keyTransport.SessionEncryptedKey.MacKey.Value,
Ukm = keyTransport.TransportParameters.Ukm.Value,
};
}
