I'm using Fiddler to setup a proxy server, but when enabling "Require Proxy Authorization" under the rules menu the username/password is always 1. How do I change the username/password?
I tried changing oSession["X-AutoAuth"] = "username:password"; but it doesn't change the proxy credentials required.
Can't find anything in the documentation regarding this...
The X-AutoAuth flag concerns what credentials Fiddler sends to an upstream server when automatically replying to an authentication challenge; it has no impact on what credentials are demanded of the user.
This question was original asked and answered here: https://groups.google.com/forum/#!topic/httpfiddler/pErxaOtMlyc
You can change the credentials expected by Fiddler by setting the preference fiddler.proxy.creds to the base64 encoded username:password string. The default value is MToX which is the base64 encoded version of the string 1:1. You can compute the base64 value you need using the Tools > TextWizard feature in Fiddler.
To update the preference, click into the QuickExec box below Fiddler's Web Sessions list and type prefs set fiddler.proxy.creds YOURBASE64StringHere and hit Enter.
来源：https://stackoverflow.com/questions/18259969/changing-username-and-password-of-fiddler-proxy-server