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.

Continue reading „TLS-Datenverkehr mit Wireshark inspizieren (HTTPS entschlüsseln)“

HTTP error code 403 when logging on to Internet Information Services (IIS) using client certificate after renewing web server certificate

Assume the following scenario:

  • A user or application accesses a web page or web application running on an Internet Information Services (IIS) web server.
  • The web server is configured to request a client certificate for the requested resource.
  • Although there is a valid client certificate on the client, the error code 403 Forbidden is returned immediately. The user is not prompted (when calling the page with a browser) to select a certificate.
  • The web server certificate was recently renewed and the IIS SSL binding was configured accordingly via the IIS Manager.
403 - Forbidden: Access is denied.
You do not have permission to view this directory or page using the credentials that you supplied.
Continue reading „HTTP Fehlercode 403 bei Anmeldung mittels Client-Zertifikat an Internet Information Services (IIS) nach Erneuerung des Webserver-Zertifikats“

Use HTTP over Transport Layer Security (HTTPS) for the revocation list distribution points (CDP) and the online responder (OCSP).

With regard to the design of the infrastructure for providing revocation information - i.e. the CRL Distribution Points (CSP) as well as the Online Responders (Online Certificate Status Protocol, OCSP) - the question arises whether these should be "secured" via Secure Sockets Layer (SSL) or Transport Layer Security (TLS).

Continue reading „Verwenden von HTTP über Transport Layer Security (HTTPS) für die Sperrlistenverteilungspunkte (CDP) und den Onlineresponder (OCSP)“

Should HTTPS be used for the Network Device Enrollment Service (NDES)?

The Network Device Enrollment Service (NDES) is Microsoft's implementation of the Simple Certificate Enrollment Protocol (SCEP) developed by Cisco in the early 2000s. The first implementation was released with Windows Server 2003.

It may come as a surprise that NDES does not use Secure Socket Layer (SSL) for the HTTP connections in the default setting to this day. This fact is explained and evaluated in more detail below.

Continue reading „Sollte HTTPS für den Registrierungsdienst für Netzwerkgeräte (NDES) verwendet werden?“

Enabling Secure Sockets Layer (SSL) for Certificate Authority Web Enrollment (CAWE).

In the default configuration, Certificate Authority Web Enrollment (CAWE) accepts only unencrypted connections via HTTP. It is recommended that the CAWE be configured for HTTP over TLS (HTTPS) to make network traffic interception more difficult. Instructions are provided below.

Continue reading „Secure Sockets Layer (SSL) für die Zertifizierungsstellen-Webregistrierung (CAWE) aktivieren“

Generating a RFC 2818 compliant certificate request for SSL certificates

Google is a major player with the Chromium project and products based on it such as Google Chrome and Microsoft Edge have moved to implement the RFC 2818 and to no longer trust certificates that no longer fulfill the RFC.

For us, the following sentence is of great explosiveness:

If a subjectAltName extension of type dNSName is present, that MUST be used as the identity. Otherwise, the (most specific) Common Name field in the Subject field of the certificate MUST be used. Although the use of the Common Name is existing practice, it is deprecated and Certification Authorities are encouraged to use the dNSName instead

https://tools.ietf.org/html/rfc2818
Continue reading „Erzeugen einer RFC 2818 konformen Zertifikatanforderung für SSL Zertifikate“

Enabling Secure Sockets Layer (SSL) for the Network Device Enrollment Service (NDES).

In the default configuration, the Network Device Enrollment Service (NDES) only accepts unencrypted connections via HTTP. It is recommended that at least the NDES administration web page be configured for HTTP over TLS (HTTPS) to make it difficult to capture network traffic. The following is a guide.

For a closer look at the need to use SSL, see the article "Should HTTPS be used for the Network Device Enrollment Service (NDES)?„.

Continue reading „Secure Sockets Layer (SSL) für den Registrierungsdienst für Netzwerkgeräte (NDES) aktivieren“
en_USEnglish