/// <summary>
/// Зашифровать информацию о ключе.
/// </summary>
public byte[] Encode()
{
var asnEncoder = new Asn1BerEncodeBuffer();
var keyTransport = new Gost_R3410_KeyTransport();
try
{
keyTransport.SessionEncryptedKey = new Gost_28147_89_EncryptedKey
{
EncryptedKey = new Gost_28147_89_Key(SessionEncryptedKey.EncryptedKey),
MacKey = new Gost_28147_89_Mac(SessionEncryptedKey.Mac)
};
keyTransport.TransportParams = new Gost_R3410_TransportParams
{
EncryptionParamSet = Gost_28147_89_ParamSet.FromString(SessionEncryptedKey.EncryptionParamSet),
EphemeralPublicKey = EncodePublicKey(TransportParameters),
Ukm = new Asn1OctetString(SessionEncryptedKey.Ukm)
};
keyTransport.Encode(asnEncoder);
}
catch (Exception exception)
{
throw ExceptionUtility.CryptographicException(exception, Resources.Asn1EncodeError, nameof(Gost_R3410_KeyTransport));
}
return(asnEncoder.MsgCopy);
}
private void DecodeSessionKey(Gost_R3410_KeyTransport keyTransport)
{
SessionEncryptedKey = new Gost_28147_89_KeyExchangeInfo
{
EncryptionParamSet = keyTransport.TransportParams.EncryptionParamSet.Oid.Value,
EncryptedKey = keyTransport.SessionEncryptedKey.EncryptedKey.Value,
Mac = keyTransport.SessionEncryptedKey.MacKey.Value,
Ukm = keyTransport.TransportParams.Ukm.Value
};
}
/// <summary>
/// Расшифровать информацию о ключе.
/// </summary>
public void Decode(byte[] data)
{
if (data == null)
{
throw ExceptionUtility.ArgumentNull(nameof(data));
}
try
{
var asnDecoder = new Asn1BerDecodeBuffer(data);
var keyTransport = new Gost_R3410_KeyTransport();
keyTransport.Decode(asnDecoder);
DecodeSessionKey(keyTransport);
DecodePublicKey(keyTransport);
}
catch (Exception exception)
{
throw ExceptionUtility.CryptographicException(exception, Resources.Asn1DecodeError, nameof(Gost_R3410_KeyTransport));
}
}
private void DecodePublicKey(Gost_R3410_KeyTransport keyTransport)
{
var publicKeyInfo = keyTransport.TransportParams.EphemeralPublicKey;
var publicKeyAlgOid = publicKeyInfo.Algorithm.Algorithm.Oid.Value;
if (!publicKeyAlgOid.Equals(KeyAlgorithm.Value))
{
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 Gost_R3410_PublicKeyParams;
if (publicKeyParams == null)
{
throw ExceptionUtility.CryptographicException(Resources.Asn1DecodeAlgorithmParameters);
}
var asnDecoder = new Asn1BerDecodeBuffer(publicKeyInfo.SubjectPublicKey.Value);
var publicKey = new Asn1OctetString();
publicKey.Decode(asnDecoder);
TransportParameters = CreateKeyExchangeParams();
TransportParameters.DigestParamSet = publicKeyParams.DigestParamSet.Oid.Value;
TransportParameters.PublicKeyParamSet = publicKeyParams.PublicKeyParamSet.Oid.Value;
TransportParameters.EncryptionParamSet = publicKeyParams.EncryptionParamSet?.Oid.Value;
TransportParameters.PublicKey = publicKey.Value;
TransportParameters.PrivateKey = null;
}