Warning pages not displayed for HTTPS sites


This article applies to:

  • WebMarshal 6.X and 7.X
  • HTTPS Content Inspection NOT enabled

Symptoms:

Some client browser software does not correctly display block or warning pages for HTTPS sites.

This behavior has been observed with a number of major web browsers and could potentially occur in others.

  • Even though WebMarshal is returning page data to the browser, these browsers choose to display their own error message instead. These messages may or may not indicate that a HTTPS connection could not be established.
  • The cause of this problem appears to be in each browser, rather than WebMarshal. Nowhere in the HTTP standards documents is it specified how a proxy server should indicate that it cannot create a HTTPS connection. WebMarshal is returning a standard error response code, but the browsers are handling this response differently than they would for a non-HTTPS request.

Workaround:

One way to work around this problem is to enable HTTPS content inspection in WebMarshal (6.1 and above). When HTTPS inspection is enabled, WebMarshal is able to create secure connections between itself and the browser. When the error page is sent inside the secure connection, the browsers appear to display the page information correctly.

You can use this workaround even if you do not want to inspect HTTPS content. To do this, enable HTTPS inspection but disable all of the HTTPS rules. This configuration will prevent WebMarshal from inspecting the content of HTTPS sites, but will allow the Proxy to create secure connections to the browser for the purpose of returning warning or block pages.

 


Last Modified 9/9/2009.
https://support.trustwave.com/kb/KnowledgebaseArticle12825.aspx