php/oauth2.php

<!--
 * Copyright 2012 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.
 *
 * Sample code for authenticating to Gmail with OAuth2. See
 * https://github.com/google/gmail-oauth2-tools/wiki
 * for documentation.
 * -->
<html>
<head>
  <title>OAuth2 IMAP example with Gmail</title>
</head>
<body>

<?php
require_once 'Zend/Mail/Protocol/Imap.php';
require_once 'Zend/Mail/Storage/Imap.php';

/**
 * Builds an OAuth2 authentication string for the given email address and access
 * token.
 */
function constructAuthString($email, $accessToken) {
  return base64_encode("user=$email\1auth=Bearer $accessToken\1\1");
}

/**
 * Given an open IMAP connection, attempts to authenticate with OAuth2.
 *
 * $imap is an open IMAP connection.
 * $email is a Gmail address.
 * $accessToken is a valid OAuth 2.0 access token for the given email address.
 *
 * Returns true on successful authentication, false otherwise.
 */
function oauth2Authenticate($imap, $email, $accessToken) {
  $authenticateParams = array('XOAUTH2',
      constructAuthString($email, $accessToken));
  $imap->sendRequest('AUTHENTICATE', $authenticateParams);
  while (true) {
    $response = "";
    $is_plus = $imap->readLine($response, '+', true);
    if ($is_plus) {
      error_log("got an extra server challenge: $response");
      // Send empty client response.
      $imap->sendRequest('');
    } else {
      if (preg_match('/^NO /i', $response) ||
          preg_match('/^BAD /i', $response)) {
        error_log("got failure response: $response");
        return false;
      } else if (preg_match("/^OK /i", $response)) {
        return true;
      } else {
        // Some untagged response, such as CAPABILITY
      }
    }
  }
}

/**
 * Given an open and authenticated IMAP connection, displays some basic info
 * about the INBOX folder.
 */
function showInbox($imap) {
  /**
   * Print the INBOX message count and the subject of all messages
   * in the INBOX
   */
  $storage = new Zend_Mail_Storage_Imap($imap);

  include 'header.php';
  echo '<h1>Total messages: ' . $storage->countMessages() . "</h1>\n";

  /**
   * Retrieve first 5 messages.  If retrieving more, you'll want
   * to directly use Zend_Mail_Protocol_Imap and do a batch retrieval,
   * plus retrieve only the headers
   */
  echo 'First five messages: <ul>';
  for ($i = 1; $i <= $storage->countMessages() && $i <= 5; $i++ ){
    echo '<li>' . htmlentities($storage->getMessage($i)->subject) . "</li>\n";
  }
  echo '</ul>';
}

/**
 * Tries to login to IMAP and show inbox stats.
 */
function tryImapLogin($email, $accessToken) {
  /**
   * Make the IMAP connection and send the auth request
   */
  $imap = new Zend_Mail_Protocol_Imap('imap.gmail.com', '993', true);
  if (oauth2Authenticate($imap, $email, $accessToken)) {
    echo '<h1>Successfully authenticated!</h1>';
    showInbox($imap);
  } else {
    echo '<h1>Failed to login</h1>';
  }
}

/**
 * Displays a form to collect the email address and access token.
 */
function displayForm($email, $accessToken) {
  echo <<<END
<form method="POST" action="oauth2.php">
  <h1>Please enter your e-mail address: </h1>
  <input type="text" name="email" value="$email"/>
  <p>
  <h1>Please enter your access token: </h1>
  <input type="text" name="access_token" value="$accessToken"/>
  <input type="submit"/>
</form>
<hr>
END;
}

$email = $_POST['email'];
$accessToken = $_POST['access_token'];

displayForm($email, $accessToken);

if ($email && $accessToken) {
  tryImapLogin($email, $accessToken);
}


?>
</body>
</html>