- http-authenticators #!optional AUTHENTICATORSparameter
This parameter allows for pluggable authentication schemes. AUTHENTICATORS is an alist mapping authentication scheme name to a procedure of 7 arguments:
(lambda (response response-header new-request request-header uri realm writer) ...)
Here, response is the response object, response-header is the name of the response header which required authentication - a symbol which is either www-authenticate or proxy-authenticate.
new-request is the request that will be sent next, to be populated with additional headers by the authenticator procedure, and request-header is the name of the request header which is expected to be provided and supplied with extra details by the authenticator - also a symbol, which is either authorization or proxy-authorization.
uri is the URI which was requested when the authorization was demanded (in case of www-authenticate, the protected resource) and realm is the authentication realm (a string).
Finally writer is the writer procedure passed by the user or fabricated by call-with-input-request based on the user's form arguments. It's always a procedure accepting a request object. This is only needed when full-request authentication is desired, to obtain a request body.