kisielk/persona.go

## persona.go
// An example of implementing Mozilla's Persona authentication system.
// follows the instructions from https://developer.mozilla.org/en-US/docs/Persona/Quick_Setup
// and doesn't do much else.
package main

import (
	"encoding/json"
	"github.com/gorilla/mux"
	"github.com/gorilla/sessions"
	"html/template"
	"log"
	"net/http"
	"net/url"
)

// The main page template.
var tmpl = `
<html>
<head>
<title>Persona Test</title>
<script src="https://login.persona.org/include.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
</head>
<body>
<div>
{{if .Email}}
Signed in as {{.Email}}: <span id="signout"><a href="#">Sign out</a></span>
{{else}}
Not signed in: <span id="signin"><a href="#">Sign in</a></span>
{{end}}
<script>
var signinLink = document.getElementById('signin');
if (signinLink) {
  signinLink.onclick = function() { navigator.id.request(); };
};
var signoutLink = document.getElementById('signout');
if (signoutLink) {
  signoutLink.onclick = function() { navigator.id.logout(); };
};

{{if .Email}}
var currentUser = {{.Email}};
{{else}}
var currentUser = null;
{{end}}

navigator.id.watch({
  loggedInUser: currentUser,
  onlogin: function(assertion) {
    // A user has logged in! Here you need to:
    // 1. Send the assertion to your backend for verification and to create a session.
    // 2. Update your UI.
    $.ajax({ /* <-- This example uses jQuery, but you can use whatever you'd like */
      type: 'POST',
      url: '/auth/login', // This is a URL on your website.
      data: {assertion: assertion},
      success: function(res, status, xhr) { window.location.reload(); },
      error: function(res, status, xhr) { alert("login failure" + res); }
    });
  },
  onlogout: function() {
    // A user has logged out! Here you need to:
    // Tear down the user's session by redirecting the user or making a call to your backend.
    // Also, make that loggedInUser will get set to null on the next page load.
    // (That's a literal JavaScript null. Not false, 0, or undefined. null.)
    $.ajax({
      type: 'POST',
      url: '/auth/logout', // This is a URL on your website.
      success: function(res, status, xhr) { window.location.reload(); },
      error: function(res, status, xhr) { alert("logout failure" + res); }
    });
  }
});
</script>
</body>
</html>
`

// the audience string as required by the Persona API. Should be adjusted as appropriate.
var audience = "http://localhost:8080"

// a session cookie store
var sessionStore = sessions.NewCookieStore([]byte("something-very-secret"))

// the name of the session cookie. Should be adjusted as appropriate
var sessionName = "persona"

// serverError is a helper function for printing server error messages
// note that we're printing error messages directly to the client,
// this is probably not a good idea in production.
func serverError(w http.ResponseWriter, s string) {
	log.Println("server error:", s)
	http.Error(w, "server error: "+s, http.StatusInternalServerError)
}

// badRequest returns a bad request status to the client with a message
func badRequest(w http.ResponseWriter, s string) {
	http.Error(w, s, http.StatusBadRequest)
}

// handleLogin is the handler for /auth/login
func handleLogin(w http.ResponseWriter, req *http.Request) {
	assertion := req.FormValue("assertion")
	if assertion == "" {
		badRequest(w, "missing assertion")
		return
	}
	resp, err := http.PostForm("https://verifier.login.persona.org/verify",
		url.Values{"assertion": {assertion}, "audience": {audience}})
	if err != nil {
		serverError(w, err.Error())
	}
	defer resp.Body.Close()
	dec := json.NewDecoder(resp.Body)
	var response struct {
		Status   string `json:"status"`
		Email    string `json:"email"`
		Audience string `json:"audience"`
		Expires  uint64 `json:"expires"`
		Issuer   string `json:"issuer"`
		Reason   string `json:"reason"` // Will only be set if Status != "okay"
	}
	if err := dec.Decode(&response); err != nil {
		serverError(w, err.Error())
	}
	if response.Status != "okay" {
		serverError(w, "authentication failed: "+response.Reason)
	}
	session, err := sessionStore.Get(req, sessionName)
	if err != nil {
		serverError(w, err.Error())
	}
	session.Values["email"] = response.Email
	if err := session.Save(req, w); err != nil {
		serverError(w, err.Error())
	}
}

// handleLogout is the handler for /auth/logout
func handleLogout(w http.ResponseWriter, req *http.Request) {
	session, err := sessionStore.Get(req, sessionName)
	if err != nil {
		serverError(w, err.Error())
	}
	delete(session.Values, "email")
	if err := session.Save(req, w); err != nil {
		serverError(w, err.Error())
	}
}

// handle is the main page handler
func handle(w http.ResponseWriter, req *http.Request) {
	t, err := template.New("main").Parse(tmpl)
	if err != nil {
		serverError(w, err.Error())
		return
	}
	session, err := sessionStore.Get(req, sessionName)
	if err != nil {
		serverError(w, err.Error())
	}
	err = t.ExecuteTemplate(w, "main", map[string]interface{}{"Email": session.Values["email"]})
	if err != nil {
		serverError(w, err.Error())
		return
	}
}

func main() {
	r := mux.NewRouter()
	r.HandleFunc("/", handle)
	r.HandleFunc("/auth/login", handleLogin).Methods("POST")
	r.HandleFunc("/auth/logout", handleLogout).Methods("POST")
	http.Handle("/", r)
	log.Fatal(http.ListenAndServe(":8080", nil))
}
	// An example of implementing Mozilla's Persona authentication system.
	// follows the instructions from https://developer.mozilla.org/en-US/docs/Persona/Quick_Setup
	// and doesn't do much else.
	package main

	import (
	"encoding/json"
	"github.com/gorilla/mux"
	"github.com/gorilla/sessions"
	"html/template"
	"log"
	"net/http"
	"net/url"
	)

	// The main page template.
	var tmpl = `
	<html>
	<head>
	<title>Persona Test</title>
	<script src="https://login.persona.org/include.js"></script>
	<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
	</head>
	<body>
	<div>
	{{if .Email}}
	Signed in as {{.Email}}: <span id="signout"><a href="#">Sign out</a></span>
	{{else}}
	Not signed in: <span id="signin"><a href="#">Sign in</a></span>
	{{end}}
	<script>
	var signinLink = document.getElementById('signin');
	if (signinLink) {
	signinLink.onclick = function() { navigator.id.request(); };
	};
	var signoutLink = document.getElementById('signout');
	if (signoutLink) {
	signoutLink.onclick = function() { navigator.id.logout(); };
	};

	{{if .Email}}
	var currentUser = {{.Email}};
	{{else}}
	var currentUser = null;
	{{end}}

	navigator.id.watch({
	loggedInUser: currentUser,
	onlogin: function(assertion) {
	// A user has logged in! Here you need to:
	// 1. Send the assertion to your backend for verification and to create a session.
	// 2. Update your UI.
	$.ajax({ /* <-- This example uses jQuery, but you can use whatever you'd like */
	type: 'POST',
	url: '/auth/login', // This is a URL on your website.
	data: {assertion: assertion},
	success: function(res, status, xhr) { window.location.reload(); },
	error: function(res, status, xhr) { alert("login failure" + res); }
	});
	},
	onlogout: function() {
	// A user has logged out! Here you need to:
	// Tear down the user's session by redirecting the user or making a call to your backend.
	// Also, make that loggedInUser will get set to null on the next page load.
	// (That's a literal JavaScript null. Not false, 0, or undefined. null.)
	$.ajax({
	type: 'POST',
	url: '/auth/logout', // This is a URL on your website.
	success: function(res, status, xhr) { window.location.reload(); },
	error: function(res, status, xhr) { alert("logout failure" + res); }
	});
	}
	});
	</script>
	</body>
	</html>
	`

	// the audience string as required by the Persona API. Should be adjusted as appropriate.
	var audience = "http://localhost:8080"

	// a session cookie store
	var sessionStore = sessions.NewCookieStore([]byte("something-very-secret"))

	// the name of the session cookie. Should be adjusted as appropriate
	var sessionName = "persona"

	// serverError is a helper function for printing server error messages
	// note that we're printing error messages directly to the client,
	// this is probably not a good idea in production.
	func serverError(w http.ResponseWriter, s string) {
	log.Println("server error:", s)
	http.Error(w, "server error: "+s, http.StatusInternalServerError)
	}

	// badRequest returns a bad request status to the client with a message
	func badRequest(w http.ResponseWriter, s string) {
	http.Error(w, s, http.StatusBadRequest)
	}

	// handleLogin is the handler for /auth/login
	func handleLogin(w http.ResponseWriter, req *http.Request) {
	assertion := req.FormValue("assertion")
	if assertion == "" {
	badRequest(w, "missing assertion")
	return
	}
	resp, err := http.PostForm("https://verifier.login.persona.org/verify",
	url.Values{"assertion": {assertion}, "audience": {audience}})
	if err != nil {
	serverError(w, err.Error())
	}
	defer resp.Body.Close()
	dec := json.NewDecoder(resp.Body)
	var response struct {
	Status string `json:"status"`
	Email string `json:"email"`
	Audience string `json:"audience"`
	Expires uint64 `json:"expires"`
	Issuer string `json:"issuer"`
	Reason string `json:"reason"` // Will only be set if Status != "okay"
	}
	if err := dec.Decode(&response); err != nil {
	serverError(w, err.Error())
	}
	if response.Status != "okay" {
	serverError(w, "authentication failed: "+response.Reason)
	}
	session, err := sessionStore.Get(req, sessionName)
	if err != nil {
	serverError(w, err.Error())
	}
	session.Values["email"] = response.Email
	if err := session.Save(req, w); err != nil {
	serverError(w, err.Error())
	}
	}

	// handleLogout is the handler for /auth/logout
	func handleLogout(w http.ResponseWriter, req *http.Request) {
	session, err := sessionStore.Get(req, sessionName)
	if err != nil {
	serverError(w, err.Error())
	}
	delete(session.Values, "email")
	if err := session.Save(req, w); err != nil {
	serverError(w, err.Error())
	}
	}

	// handle is the main page handler
	func handle(w http.ResponseWriter, req *http.Request) {
	t, err := template.New("main").Parse(tmpl)
	if err != nil {
	serverError(w, err.Error())
	return
	}
	session, err := sessionStore.Get(req, sessionName)
	if err != nil {
	serverError(w, err.Error())
	}
	err = t.ExecuteTemplate(w, "main", map[string]interface{}{"Email": session.Values["email"]})
	if err != nil {
	serverError(w, err.Error())
	return
	}
	}

	func main() {
	r := mux.NewRouter()
	r.HandleFunc("/", handle)
	r.HandleFunc("/auth/login", handleLogin).Methods("POST")
	r.HandleFunc("/auth/logout", handleLogout).Methods("POST")
	http.Handle("/", r)
	log.Fatal(http.ListenAndServe(":8080", nil))
	}