Checking the certificate creation

SenderTest/SenderEncryptionWithCertificateTest.cs

@@ -61,6 +61,12 @@ public class SenderEncryptionWithCertificateTest {
         var req = new CertificateRequest("cn=foobar", ECDsa.Create(), HashAlgorithmName.SHA256);
         var cert = req.CreateSelfSigned(DateTimeOffset.Now, DateTimeOffset.Now.AddYears(5));
 
+        if (cert.GetRSAPublicKey() == null)
+            throw new Exception("Certificate does not contain a public key");
+
+        if (cert.GetRSAPrivateKey() == null)
+            throw new Exception("Certificate does not contain a private key");
+
         // Export the certificate to a PEM file, just for
         // additional extern testing
         if (exportPath != null) {