- determine-proxy-username/password #!optional HANDLERparameter
The procedure in this parameter is called whenever the proxy requests authentication via a 407 Proxy Authentication Required response. This basically works the same as authentication against an origin server.
The HANDLER is a procedure of two arguments; the URI for the proxy currently being used and the realm (a string) which wants credentials. The procedure should return two string values: the username and the password to use for authentication.
The default value is a procedure which extracts the username and password components from the proxy's URI.