public static AsymmetricAlgorithm GetPublicKeyAlgorithm(this X509Certificate2 certificate) { if (certificate == null) { throw ExceptionUtility.ArgumentNull("certificate"); } var cspObject = new GostKeyExchangeParameters(); cspObject.DecodeParameters(certificate.PublicKey.EncodedParameters.RawData); cspObject.DecodePublicKey(certificate.PublicKey.EncodedKeyValue.RawData); var cspBlobData = CryptoApiHelper.EncodePublicBlob(cspObject); var publicKey = new Gost3410AsymmetricAlgorithm(); publicKey.ImportCspBlob(cspBlobData); return publicKey; }