KB No. 13: TLS decryption: Handshake failure

 

Meaning

This page means that Olfeo SaaS and the machine serving the requested domain were unable to establish a TLS connection before processing the request. This can happen for a number of reasons, including issues related to how the server is configured or the certificate of the remote site itself.

But why does a workstation not protected by Olfeo SaaS allow this page to be displayed?

The difference between Olfeo SaaS and a "standard" browser lies in a fundamental difference in approach. The goal of a browser is to display as many pages as possible, even if it means compromising on connection security. The goal of Olfeo SaaS is to provide secure browsing, which necessarily means being a little stricter.

What should I do?

You can contact the site administrator to report a possible configuration issue with their server and/or the TLS certificate associated with the domain.

You can exclude this domain from decryption; the content of responses will not be analyzed, but your users' requests will be logged.

Learn more about TLS and decryption...

Understanding How HTTPS Works?

The TLS protocol (Wikipedia)

ANSSI security recommendations for companies regarding the use of TLS.