racket/collects/web-server/http/basic-auth.rkt

32 lines
1.1 KiB
Racket

#lang racket/base
(require racket/contract
racket/match
net/base64
web-server/http/request-structs)
(define (request->basic-credentials req)
(define headers (request-headers/raw req))
(match (headers-assq* #"Authorization" headers)
[#f #f]
[(struct header (_ basic-credentials))
(cond
[(and (basic? basic-credentials)
(regexp-match #rx"([^:]*):(.*)"
(base64-decode (subbytes basic-credentials 6 (bytes-length basic-credentials)))))
=> (lambda (user-pass)
(cons (cadr user-pass) (caddr user-pass)))]
[else #f])]))
;; basic?: bytes -> (or/c (listof bytes) #f)
;; does the second part of the authorization header start with #"Basic "
(define basic?
(let ([rx (byte-regexp #"^Basic .*")])
(lambda (a) (regexp-match rx a))))
(define (make-basic-auth-header realm)
(make-header #"WWW-Authenticate" (string->bytes/utf-8 (format "Basic realm=\"~a\"" realm))))
(provide/contract
[make-basic-auth-header (string? . -> . header?)]
[request->basic-credentials (request? . -> . (or/c false/c (cons/c bytes? bytes?)))])