The Microsoft-PEF-WebProxy provider focuses on capturing traffic at the Application layer of the network stack. It is based on Fiddler and enables you to capture HTTP traffic and unencrypted HTTPS traffic to and from a client web browser. However, the PEF-WebProxy provider will not capture HTTPS browser traffic unless you configure Internet options to use a proxy server for the LAN.
Important To use the PEF-WebProxy provider, you must have the Fiddler library from Telerik installed. If you have not already installed this library, you can download it here. Note that if you select the WebProxy provider without having the library installed when you are configuring a Live Trace Session, or when specifying it in a PowerShell script, you will receive an error message that asks you to download the Fiddler library.
The Microsoft-PEF-WebProxy provider is used by the Message Analyzer Unencrypted HTTPS Trace Scenario to capture client browser traffic. When you use this provider, it also installs and registers the HTTP proxy on the machine that is running Message Analyzer, where it is configured as a system proxy for Microsoft Windows Internet (WinInet) Services. The HTTP proxy is then substituted for the proxy server when a trace is started so that it can intercept and capture unencrypted HTTPS traffic. The proxy server target is restored when the trace is complete.
As the system proxy, all HTTPS requests from WinInet flow through the HTTP proxy before reaching target web servers. Similarly, all HTTPS responses flow through the HTTP proxy before being returned to the client application.
The settings that you can configure for the WebProxy provider are described in WebProxy Filters. This includes settings for the Hostname Filter and Port Filter, in addition to HTTPS Client Certificate specifications.