auth wrapper for httprouter

README.md

Demostrates how to create a Basic Auth wrapper for httprouter Handles.

This example was taken from the httprouter package's README.

auth.go

// Basic Auth wrapper for httprouter Handles.
// See https://github.com/julienschmidt/httprouter#basic-authentication.
package main

import (
    "bytes"
    "encoding/base64"
    "fmt"
    "github.com/julienschmidt/httprouter"
    "net/http"
    "log"
    "strings"
)

func BasicAuth(h httprouter.Handle, user, pass []byte) httprouter.Handle {
    return func(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
        const basicAuthPrefix string = "Basic "

        // Get the Basic Authentication credentials
        auth := r.Header.Get("Authorization")
        if strings.HasPrefix(auth, basicAuthPrefix) {
            // Check credentials
            payload, err := base64.StdEncoding.DecodeString(auth[len(basicAuthPrefix):])
            if err == nil {
                pair := bytes.SplitN(payload, []byte(":"), 2)
                if len(pair) == 2 && bytes.Equal(pair[0], user) && bytes.Equal(pair[1], pass) {
                    // Delegate request to the given handle
                    h(w, r, ps)
                    return
                }
            }
        }

        // Request Basic Authentication otherwise
        w.Header().Set("WWW-Authenticate", "Basic realm=Restricted")
        http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
    }
}

func Index(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
    fmt.Fprint(w, "Not protected!\n")
}

func Protected(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
    fmt.Fprint(w, "Protected!\n")
}

func main() {
    user := []byte("gordon")
    pass := []byte("secret!")

    router := httprouter.New()
    router.GET("/", Index)
    router.GET("/protected/", BasicAuth(Protected, user, pass))

    log.Fatal(http.ListenAndServe(":8080", router))
}