Si tratta di un sistema piuttosto semplice. Prima si copia il codice Javascript con i codici di accesso e li si inserisce nella pagina HTML di login
Per prima cosa ho modificato la pagina di tutorial eliminando la possibilita' di registrarsi con la mail. L'idea e' che l'amministratore inserisce a mano gli utenti che possono loggarsi eliminando gli accessi anonimi
Questa e' la pagina di login ed il relativo codice (in giallo nel codice i comandi per l'autenticazione con Firebase)
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<!DOCTYPE html>
<!--
Copyright (c) 2016 Google Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<html>
<head>
<meta charset=utf-8 />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Email/Password Authentication Example</title>
<!-- Material Design Theming -->
<link rel="stylesheet" href="https://code.getmdl.io/1.1.3/material.orange-indigo.min.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
<script defer src="https://code.getmdl.io/1.1.3/material.min.js"></script>
<link rel="stylesheet" href="main.css">
<!-- Firebase -->
<script src="https://www.gstatic.com/firebasejs/3.6.4/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: "AIzaSyAchx8oVeLUgYnGujAXXXXXXXXXXXXXXX",
authDomain: "notifXXXXXXXXX.firebaseapp.com",
databaseURL: "https://notiXXXXXXXX.firebaseio.com",
storageBucket: "notifXXXXXXX.appspot.com",
messagingSenderId: "392XXXXXXXX"
};
firebase.initializeApp(config);
</script>
<script type="text/javascript">
/**
* Handles the sign in button press.
*/
function toggleSignIn() {
if (firebase.auth().currentUser) {
// [START signout]
firebase.auth().signOut();
// [END signout]
} else {
var email = document.getElementById('email').value;
var password = document.getElementById('password').value;
// Sign in with email and pass.
// [START authwithemail]
firebase.auth().signInWithEmailAndPassword(email, password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// [START_EXCLUDE]
if (errorCode === 'auth/wrong-password') {
alert('Wrong password.');
} else {
alert(errorMessage);
}
console.log(error);
});
}
}
function initApp() {
firebase.auth().onAuthStateChanged(function(user) {
if (user) {
window.location.href = "email3.html";
}
});
document.getElementById('quickstart-sign-in').addEventListener('click', toggleSignIn, false);
}
window.onload = function() {
initApp();
};
</script>
</head>
<body>
<div class="demo-layout mdl-layout mdl-js-layout mdl-layout--fixed-header">
<!-- Header section containing title -->
<header class="mdl-layout__header mdl-color-text--white mdl-color--light-blue-700">
</header>
<main class="mdl-layout__content mdl-color--grey-100">
<div class="mdl-cell mdl-cell--12-col mdl-cell--12-col-tablet mdl-grid">
<!-- Container for the demo -->
<div class="mdl-card mdl-shadow--2dp mdl-cell mdl-cell--12-col mdl-cell--12-col-tablet mdl-cell--12-col-desktop">
<div class="mdl-card__title mdl-color--light-blue-600 mdl-color-text--white">
<h2 class="mdl-card__title-text">Firebase Email & Password Authentication</h2>
</div>
<div class="mdl-card__supporting-text mdl-color-text--grey-600">
<p>Enter an email and password below and either sign in to an existing account or sign up</p>
<input class="mdl-textfield__input" style="display:inline;width:auto;" type="text" id="email" name="email" placeholder="Email"/>
<input class="mdl-textfield__input" style="display:inline;width:auto;" type="password" id="password" name="password" placeholder="Password"/>
<br/><br/>
<button class="mdl-button mdl-js-button mdl-button--raised" id="quickstart-sign-in" name="signin">Sign In</button>
</div>
</div>
</div>
</main>
</div>
</body>
</html>
-------------------
Se l'autenticazione e' corretta allora passa automaticamente alla pagina 2. Se si accede direttamente alla pagina 2 senza autenticazione questa rimanda indietro alla pagina di login.
email3.html
------------------
<!DOCTYPE html>
<!--
Copyright (c) 2016 Google Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<html>
<head>
<meta charset=utf-8 />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Email/Password Authentication Example</title>
<!-- Material Design Theming -->
<link rel="stylesheet" href="https://code.getmdl.io/1.1.3/material.orange-indigo.min.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
<script defer src="https://code.getmdl.io/1.1.3/material.min.js"></script>
<link rel="stylesheet" href="main.css">
<!-- Firebase -->
<script src="https://www.gstatic.com/firebasejs/3.6.4/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: "AIzaSyAchx8oVeLUgYnGujAEfXXXXXXXXXXXXX",
authDomain: "XXXXXXXXX.firebaseapp.com",
databaseURL: "https://XXXXXXXX5.firebaseio.com",
storageBucket: "XXXXXXXXX.appspot.com",
messagingSenderId: "39272XXXXXXXX"
};
firebase.initializeApp(config);
</script>
<script type="text/javascript">
/**
* Handles the sign in button press.
*/
function toggleSignIn() {
if (firebase.auth().currentUser) {
// [START signout]
firebase.auth().signOut();
window.location.href = "email2.html";
// [END signout]
} else {
var email = document.getElementById('email').value;
// Sign in with email and pass.
// [START authwithemail]
firebase.auth().signInWithEmailAndPassword(email, password).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// [START_EXCLUDE]
if (errorCode === 'auth/wrong-password') {
alert('Wrong password.');
} else {
alert(errorMessage);
}
console.log(error);
document.getElementById('quickstart-sign-in').disabled = false;
// [END_EXCLUDE]
});
// [END authwithemail]
}
document.getElementById('quickstart-sign-in').disabled = true;
}
/**
* initApp handles setting up UI event listeners and registering Firebase auth listeners:
* - firebase.auth().onAuthStateChanged: This listener is called when the user is signed in or
* out, and that is where we update the UI.
*/
function initApp() {
// Listening for auth state changes.
// [START authstatelistener]
firebase.auth().onAuthStateChanged(function(user) {
if (user) {
// User is signed in.
var displayName = user.displayName;
var email = user.email;
var emailVerified = user.emailVerified;
var photoURL = user.photoURL;
var isAnonymous = user.isAnonymous;
var uid = user.uid;
var providerData = user.providerData;
// [START_EXCLUDE silent]
document.getElementById('quickstart-sign-in-status').textContent = 'Signed in';
document.getElementById('quickstart-sign-in').textContent = 'Sign out';
document.getElementById('quickstart-account-details').textContent = JSON.stringify(user, null, ' ');
// [END_EXCLUDE]
} else {
window.location.href = "email2.html";
}
});
// [END authstatelistener]
document.getElementById('quickstart-sign-in').addEventListener('click', toggleSignIn, false);
}
window.onload = function() {
initApp();
};
</script>
</head>
<body>
<div class="demo-layout mdl-layout mdl-js-layout mdl-layout--fixed-header">
<!-- Header section containing title -->
<header class="mdl-layout__header mdl-color-text--white mdl-color--light-blue-700">
<div class="mdl-cell mdl-cell--12-col mdl-cell--12-col-tablet mdl-grid">
<div class="mdl-layout__header-row mdl-cell mdl-cell--12-col mdl-cell--12-col-tablet mdl-cell--8-col-desktop">
<a href="/"><h3>Firebase Authentication</h3></a>
</div>
</div>
</header>
<main class="mdl-layout__content mdl-color--grey-100">
<div class="mdl-cell mdl-cell--12-col mdl-cell--12-col-tablet mdl-grid">
<!-- Container for the demo -->
<div class="mdl-card mdl-shadow--2dp mdl-cell mdl-cell--12-col mdl-cell--12-col-tablet mdl-cell--12-col-desktop">
<div class="mdl-card__title mdl-color--light-blue-600 mdl-color-text--white">
<h2 class="mdl-card__title-text">Firebase Email & Password Authentication</h2>
</div>
<div class="mdl-card__supporting-text mdl-color-text--grey-600">
<button class="mdl-button mdl-js-button mdl-button--raised" id="quickstart-sign-in" name="signin">Sign In</button>
<!-- Container where we'll display the user details -->
<div class="quickstart-user-details-container">
Firebase sign-in status: <span id="quickstart-sign-in-status">Unknown</span>
<div>Firebase auth <code>currentUser</code> object value:</div>
<pre><code id="quickstart-account-details">null</code></pre>
</div>
</div>
</div>
</div>
</main>
</div>
</body>
</html>
------------------
Stamani riprendendo in mano la cosa mi sono accorto di un nuovo utente che si era registrato (vedi l'ultima riga della tabella sottostante) senza nessun intervento. Visto che i codici di autenticazione sono inclusi in Javascript e non sono mascherabili e' abbastanza semplice fare un codice HTML che crei un login anonimo via email
a quanto pare non e' possibile limitare questo comportamento. L'unica possibilita' di filtro e' a livello di permessi di accesso alla base dati
