Testing of network services represents one of the biggest challenges in cyber security. Because new vulnerabilities are detected on a regular basis, more research is needed. These faults have their roots in the software development cycle or because of intrinsic leaks in the system specification. Conformance testing checks whether a system behaves according to its specification. Here model-based testing provides several methods for automated detection of shortcomings. The formal specification of a system behavior represents the starting point of the testing process. In this paper, a widely used cryptographic protocol is specified and tested for conformance with a test execution framework. The first empirical results are presented and discussed.