What ProxySG configurations and policy are required for proxy authentication to work with Microsoft Edge in a transparent deployment?

Products

• ProxySG Software - SGOS

Issue/Introduction

To prevent IWA authentication failure with Microsoft Edge in a transparent deployment, do the following:

1. Use an HTTPS virtual URL. Microsoft Edge is more security-conscious than Internet Explorer and does not follow HTTPS-to-HTTP redirects in some cases.
2. Use a hostname for the virtual URL that does not contain any dots. The browser resolves the name using an imputing DNS suffix.
3. Use the following policy to allow credentialed CORS requests. For now, HTTP methods such as POST and OPTIONS also must be exempted from authentication because Edge does not let the ProxySG appliance redirect them to virtual URLs.

 

Resolution

<Proxy>
    ; Allow OPTIONS and POST without authentication, since Edge won’t let ProxySG to redirect them.
    ; OPTIONS is a CORS “preflight” request which can’t be redirected.
    allow http.method=OPTIONS||POST
    authenticate(iwa_realm) authenticate.mode(origin-cookie-redirect)
 
    
<Proxy>
    ; Add CORS headers to allow inline requests to be redirected to the virtual URL and back again.
   request.x_header.Origin.exists=yes action.cors(yes)
define action cors
    set(exception.response.x_header.Access-Control-Allow-Origin,"$(request.x_header.Origin)")
    set(exception.response.x_header.Access-Control-Allow-Credentials, "true")
    set(response.x_header.Access-Control-Allow-Origin, "$(request.x_header.Origin)")
    set(response.x_header.Access-Control-Allow-Credentials, "true")
end