auth

Auth0 Wrapper

A package to make it easier to handle Auth0 authorization and check whether a user is valid or has permissions based on API scopes.

Setup

• Create scopes for your API in Auth0.
• If using ValidUser, add a custom claims rule in Auth0 to include your key in the access token returned to the user:

function (user, context, callback) {
 context.accessToken['http://example.com/username'] = user.username;
 return callback(null, user, context);
}

Install

go get github.com/ashmidgley/auth

Usage

JWT Middleware

Use the middleware to enforce authorization on routes:

package main

import (
  "net/http"
  
  "github.com/ashmidgley/auth"
  "github.com/example/api/users"
  "github.com/example/api/scores"
  "github.com/gorilla/mux"
)

func main() {
  router := mux.NewRouter()
  jwtMiddleware := auth.GetJwtMiddleware("example_audience", "example_issuer")
  
  router.Handle("/api/users", jwtMiddleware.Handler(users.GetUsers)).Methods("GET")
  router.Handle("/api/scores", jwtMiddleware.Handler(scores.CreateScore)).Methods("POST")
  
  http.ListenAndServe(":8080", router)
}

Has Permission?

Ensure a requester has a specified permission before performing an action:

package users

import (
  "fmt"
  "net/http"
  
  "github.com/ashmidgley/auth"
)

var GetUsers = http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
  up := auth.UserPermission{
    Request:    request,
    Permission: "read_users",
  }

  if hasPermission, err := auth.HasPermission(up); err != nil {
    http.Error(writer, fmt.Sprintf("%v\n", err), http.StatusInternalServerError)
    return
  } else if !hasPermission {
    http.Error(writer, "invalid permissions to make request", http.StatusUnauthorized)
    return
  }
  
  // User has permission...
})

Valid User?

Confirm the requester is either making changes to their own data or has the correct permission to complete the action. Note that the UserValidation 'Identifier' value below is the same as we specified in our custom claims rule in Setup.

package scores

import (
  "fmt"
  "net/http"
  
  "github.com/ashmidgley/auth"
)

var CreateScore = http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
  user := getUser(request)
  
  uv := auth.UserValidation{
    Request:    request,
    Permission: "write_scores",
    Identifier: "http://example.com/username",
    Key:        user.username,
  }

  if code, err := auth.ValidUser(uv); err != nil {
    http.Error(writer, fmt.Sprintf("%v\n", err), code)
    return
  }

  // User is valid...
})