GO Paseto Middleware

A middleware that will check that a Paseto token is sent in a request. It will then set the contents of the token into the context of the request.

This module allows you authenticate HTTP requests using Paseto.

Installing

go get github.com/aaomidi/go-paseto-middleware

Using it

This library is written for use with o1egl's paseto library.

You can use the pasetomiddleware with default net/http as follows:

package auth

type Backend struct {
	secretKey string
}

func Auth() *Backend {
	if authBackendInstance == nil {
		authBackendInstance = &Backend{
			secretKey: "YELLOW SUBMARINE, BLACK WIZARDRY", // Obviously don't use this exact string.
		}
	}

	return authBackendInstance
}

func (backend *Backend) Middleware(optional bool) *pasetomiddleware.PasetoMiddleware {
	middleware, _ := pasetomiddleware.New(
		pasetomiddleware.Extractor(func(r *http.Request) (string, error) {
			cookie, err := r.Cookie("paseto")
			if err != nil {
				return "", err
			}
			return cookie.Value, nil
		}),

		pasetomiddleware.Decryptor(func(pas string, token *paseto.JSONToken, footer *string) error {
			v2 := paseto.NewV2()
			err := v2.Decrypt(pas, []byte(backend.secretKey), token, footer)
			return err
		}),
		pasetomiddleware.CredentialsOptional(optional),

		pasetomiddleware.Debug(optional),
	)

	return middleware
}

    package api

    router := mux.newRouter()

    router.Handle("/profile", auth.Auth().Middleware(false).NextFunc(profile)).Methods("GET")
    // You can also use .Next(http.Handler) to add another middleware.

To get the token from the request, you will do the following:

// This is initiated before.
var authedMiddleware *pasetomiddleware.PasetoMiddleware

func getUUIDFromRequest(r *http.Request) (uuid.UUID, error) {
	t, ok := r.Context().Value(authedMiddleware.TokenProperty).(*paseto.JSONToken)
	if !ok {
		return uuid.New(), errors.New("token not valid")
	}

    // I put the UUID string with the user key into the token Map
	id := t.Get("user")
	if id == "" {
		return uuid.New(), errors.New("token not valid")
	}

    // Parses the UUID
	uid, err := uuid.Parse(fmt.Sprint(id))
	return uid, err
}

Inspiration

This project was heavily inspired by GO-JWT-Middleware.