golang-utils/utils/http/servauth/servauth.go

package servauth

import (
	"log"
	"net/http"
)

func BasicAuth(handler http.Handler, username, password, realm string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if realm == "" {
			realm = "Please enter username and password"
		}

		u, p, ok := r.BasicAuth()
		if !ok {
			w.Header().Set("WWW-Authenticate", `Basic realm="`+realm+`"`)
			w.WriteHeader(401)
			if _, err := w.Write([]byte("Unauthorised\n")); err != nil {
				log.Printf("%s\n", err.Error())
			}
			return
		}

		if u != username {
			w.Header().Set("WWW-Authenticate", `Basic realm="`+realm+`"`)
			w.WriteHeader(401)
			if _, err := w.Write([]byte("Unauthorised\n")); err != nil {
				log.Printf("%s\n", err.Error())
			}
			return
		}

		if p != password {
			w.Header().Set("WWW-Authenticate", `Basic realm="`+realm+`"`)
			w.WriteHeader(401)
			if _, err := w.Write([]byte("Unauthorised\n")); err != nil {
				log.Printf("%s\n", err.Error())
			}
			return
		}

		handler.ServeHTTP(w, r)
	})
}