Wireshark - Uwe Gradenegger

Google Chrome reports error code "ERR_SSL_PROTOCOL_ERROR" when calling a web page

Assume the following scenario:

A web page is accessed using Google Chrome.
The connection setup fails with the following error message:

This website cannot provide a secure connection
test.intra.adcslabor.com has sent an invalid response.
Try to run the Windows network diagnostics.
ERR_SSL_PROTOCOL_ERROR

Basics of online responders (Online Certificate Status Protocol, OCSP)

Certificates usually have a "CRL Distribution Points" extension that tells an application where the certificate's associated Certificate Revocation List (CRL) can be found.

This is like a telephone directory: It contains all the serial numbers of certificates that have been recalled by the certification authority (and are still valid). Every application that checks the revocation status must download and evaluate the entire revocation list.

As the size increases, this procedure becomes increasingly inefficient. As a rule of thumb, 100,000 recalled certificates already correspond to approx. 5 MB file size for the revocation list.

The Online Certificate Status Protocol (OCSP) was developed for this purpose (under the leadership of ValiCert): It is similar to a directory assistance service where applications can request the revocation status for individual certificates, thus eliminating the need to download the entire CRL. OCSP is available in the RFC 6960 specified.

Inspect TLS traffic with Wireshark (decrypt HTTPS)

When troubleshooting, it can be very helpful to view encrypted SSL connections in order to inspect the messages within. There is a relatively simple way to do this with Wireshark.

Analyze network problems with Wireshark without installing software on production systems

Often, problems with the public key infrastructure can be found in the underlying network - for example, if a firewall rule is missing from the network.

Thus, it is helpful if one is able to record network traffic in order to analyze it. Excellent tools exist for this purpose, such as Wiresharkbut these require that an installation be made on the system in question, which cannot and should not be done easily on a production system.

Fortunately, the Windows Server operating system has a built-in mechanism to capture network packets. However, the resulting files are not compatible with Wireshark. The Microsoft proprietary tool, Message Analyzer, was discontinued on Nov 25, 2019 and the download links removed.

The following therefore describes how such a recording can be generated and subsequently converted into a Wireshark-compatible format in order to be able to analyze the recording away from the server in question.