public void KeyStoreRecognisesIdForPublicKey()
        {
            RSAParameters publicKey;
            RSAParameters privateKey;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportParameters(PrivateTestKey);
                publicKey  = rsa.ExportParameters(false);
                privateKey = rsa.ExportParameters(true);
            }

            KeyStore.GetPublicKey(Arg.Any <string>()).Returns(publicKey);
            KeyStore.GetPrivateKey(Arg.Any <string>()).Returns(privateKey);
        }