PHP Classes

File: example/GoogleClient/auth/Google_OAuth2.php

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File: example/GoogleClient/auth/Google_OAuth2.php
Role: Example script
Content type: text/plain
Description: Example script
Class: Viv OAuth IMAP
Access messages in IMAP server using OAuth token
Author: By
Last change: Update of example/GoogleClient/auth/Google_OAuth2.php
Date: 2 months ago
Size: 14,862 bytes
 

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<?php /* * Copyright 2008 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. */ require_once "Google_Verifier.php"; require_once "Google_LoginTicket.php"; require_once "service/Google_Utils.php"; /** * Authentication class that deals with the OAuth 2 web-server authentication flow * * @author Chris Chabot <chabotc@google.com> * @author Chirag Shah <chirags@google.com> * */ class Google_OAuth2 extends Google_Auth { public $clientId; public $clientSecret; public $developerKey; public $token; public $redirectUri; public $state; public $accessType = 'offline'; public $approvalPrompt = 'force'; public $requestVisibleActions; /** @var Google_AssertionCredentials $assertionCredentials */ public $assertionCredentials; const OAUTH2_REVOKE_URI = 'https://accounts.google.com/o/oauth2/revoke'; const OAUTH2_TOKEN_URI = 'https://accounts.google.com/o/oauth2/token'; const OAUTH2_AUTH_URL = 'https://accounts.google.com/o/oauth2/auth'; const OAUTH2_FEDERATED_SIGNON_CERTS_URL = 'https://www.googleapis.com/oauth2/v1/certs'; const CLOCK_SKEW_SECS = 300; // five minutes in seconds const AUTH_TOKEN_LIFETIME_SECS = 300; // five minutes in seconds const MAX_TOKEN_LIFETIME_SECS = 86400; // one day in seconds /** * Instantiates the class, but does not initiate the login flow, leaving it * to the discretion of the caller (which is done by calling authenticate()). */ public function __construct() { global $apiConfig; if (! empty($apiConfig['developer_key'])) { $this->developerKey = $apiConfig['developer_key']; } if (! empty($apiConfig['oauth2_client_id'])) { $this->clientId = $apiConfig['oauth2_client_id']; } if (! empty($apiConfig['oauth2_client_secret'])) { $this->clientSecret = $apiConfig['oauth2_client_secret']; } if (! empty($apiConfig['oauth2_redirect_uri'])) { $this->redirectUri = $apiConfig['oauth2_redirect_uri']; } if (! empty($apiConfig['oauth2_access_type'])) { $this->accessType = $apiConfig['oauth2_access_type']; } if (! empty($apiConfig['oauth2_approval_prompt'])) { $this->approvalPrompt = $apiConfig['oauth2_approval_prompt']; } } /** * @param $service * @param string|null $code * @throws Google_AuthException * @return string */ public function authenticate($service, $code = null) { if (!$code && isset($_GET['code'])) { $code = $_GET['code']; } if ($code) { // We got here from the redirect from a successful authorization grant, fetch the access token $request = Google_Client::$io->makeRequest(new Google_HttpRequest(self::OAUTH2_TOKEN_URI, 'POST', array(), array( 'code' => $code, 'grant_type' => 'authorization_code', 'redirect_uri' => $this->redirectUri, 'client_id' => $this->clientId, 'client_secret' => $this->clientSecret ))); if ($request->getResponseHttpCode() == 200) { $this->setAccessToken($request->getResponseBody()); $this->token['created'] = time(); return $this->getAccessToken(); } else { $response = $request->getResponseBody(); $decodedResponse = json_decode($response, true); if ($decodedResponse != null && $decodedResponse['error']) { $response = $decodedResponse['error']; } throw new Google_AuthException("Error fetching OAuth2 access token, message: '$response'", $request->getResponseHttpCode()); } } $authUrl = $this->createAuthUrl($service['scope']); header('Location: ' . $authUrl); return true; } /** * Create a URL to obtain user authorization. * The authorization endpoint allows the user to first * authenticate, and then grant/deny the access request. * @param string $scope The scope is expressed as a list of space-delimited strings. * @return string */ public function createAuthUrl($scope) { $params = array( 'response_type=code', 'redirect_uri=' . urlencode($this->redirectUri), 'client_id=' . urlencode($this->clientId), 'scope=' . urlencode($scope), 'access_type=' . urlencode($this->accessType), 'approval_prompt=' . urlencode($this->approvalPrompt), ); // if the list of scopes contains plus.login, add request_visible_actions // to auth URL if(strpos($scope, 'plus.login') && count($this->requestVisibleActions) > 0) { $params[] = 'request_visible_actions=' . urlencode($this->requestVisibleActions); } if (isset($this->state)) { $params[] = 'state=' . urlencode($this->state); } $params = implode('&', $params); return self::OAUTH2_AUTH_URL . "?$params"; } /** * @param string $token * @throws Google_AuthException */ public function setAccessToken($token) { $token = json_decode($token, true); if ($token == null) { throw new Google_AuthException('Could not json decode the token'); } if (! isset($token['access_token'])) { throw new Google_AuthException("Invalid token format"); } $this->token = $token; } public function getAccessToken() { return json_encode($this->token); } public function setDeveloperKey($developerKey) { $this->developerKey = $developerKey; } public function setState($state) { $this->state = $state; } public function setAccessType($accessType) { $this->accessType = $accessType; } public function setApprovalPrompt($approvalPrompt) { $this->approvalPrompt = $approvalPrompt; } public function setAssertionCredentials(Google_AssertionCredentials $creds) { $this->assertionCredentials = $creds; } /** * Include an accessToken in a given apiHttpRequest. * @param Google_HttpRequest $request * @return Google_HttpRequest * @throws Google_AuthException */ public function sign(Google_HttpRequest $request) { // add the developer key to the request before signing it if ($this->developerKey) { $requestUrl = $request->getUrl(); $requestUrl .= (strpos($request->getUrl(), '?') === false) ? '?' : '&'; $requestUrl .= 'key=' . urlencode($this->developerKey); $request->setUrl($requestUrl); } // Cannot sign the request without an OAuth access token. if (null == $this->token && null == $this->assertionCredentials) { return $request; } // Check if the token is set to expire in the next 30 seconds // (or has already expired). if ($this->isAccessTokenExpired()) { if ($this->assertionCredentials) { $this->refreshTokenWithAssertion(); } else { if (! array_key_exists('refresh_token', $this->token)) { throw new Google_AuthException("The OAuth 2.0 access token has expired, " . "and a refresh token is not available. Refresh tokens are not " . "returned for responses that were auto-approved."); } $this->refreshToken($this->token['refresh_token']); } } // Add the OAuth2 header to the request $request->setRequestHeaders( array('Authorization' => 'Bearer ' . $this->token['access_token']) ); return $request; } /** * Fetches a fresh access token with the given refresh token. * @param string $refreshToken * @return void */ public function refreshToken($refreshToken) { $this->refreshTokenRequest(array( 'client_id' => $this->clientId, 'client_secret' => $this->clientSecret, 'refresh_token' => $refreshToken, 'grant_type' => 'refresh_token' )); } /** * Fetches a fresh access token with a given assertion token. * @param Google_AssertionCredentials $assertionCredentials optional. * @return void */ public function refreshTokenWithAssertion($assertionCredentials = null) { if (!$assertionCredentials) { $assertionCredentials = $this->assertionCredentials; } $this->refreshTokenRequest(array( 'grant_type' => 'assertion', 'assertion_type' => $assertionCredentials->assertionType, 'assertion' => $assertionCredentials->generateAssertion(), )); } private function refreshTokenRequest($params) { $http = new Google_HttpRequest(self::OAUTH2_TOKEN_URI, 'POST', array(), $params); $request = Google_Client::$io->makeRequest($http); $code = $request->getResponseHttpCode(); $body = $request->getResponseBody(); if (200 == $code) { $token = json_decode($body, true); if ($token == null) { throw new Google_AuthException("Could not json decode the access token"); } if (! isset($token['access_token']) || ! isset($token['expires_in'])) { throw new Google_AuthException("Invalid token format"); } $this->token['access_token'] = $token['access_token']; $this->token['expires_in'] = $token['expires_in']; $this->token['created'] = time(); } else { throw new Google_AuthException("Error refreshing the OAuth2 token, message: '$body'", $code); } } /** * Revoke an OAuth2 access token or refresh token. This method will revoke the current access * token, if a token isn't provided. * @throws Google_AuthException * @param string|null $token The token (access token or a refresh token) that should be revoked. * @return boolean Returns True if the revocation was successful, otherwise False. */ public function revokeToken($token = null) { if (!$token) { $token = $this->token['access_token']; } $request = new Google_HttpRequest(self::OAUTH2_REVOKE_URI, 'POST', array(), "token=$token"); $response = Google_Client::$io->makeRequest($request); $code = $response->getResponseHttpCode(); if ($code == 200) { $this->token = null; return true; } return false; } /** * Returns if the access_token is expired. * @return bool Returns True if the access_token is expired. */ public function isAccessTokenExpired() { if (null == $this->token) { return true; } // If the token is set to expire in the next 30 seconds. $expired = ($this->token['created'] + ($this->token['expires_in'] - 30)) < time(); return $expired; } // Gets federated sign-on certificates to use for verifying identity tokens. // Returns certs as array structure, where keys are key ids, and values // are PEM encoded certificates. private function getFederatedSignOnCerts() { // This relies on makeRequest caching certificate responses. $request = Google_Client::$io->makeRequest(new Google_HttpRequest( self::OAUTH2_FEDERATED_SIGNON_CERTS_URL)); if ($request->getResponseHttpCode() == 200) { $certs = json_decode($request->getResponseBody(), true); if ($certs) { return $certs; } } throw new Google_AuthException( "Failed to retrieve verification certificates: '" . $request->getResponseBody() . "'.", $request->getResponseHttpCode()); } /** * Verifies an id token and returns the authenticated apiLoginTicket. * Throws an exception if the id token is not valid. * The audience parameter can be used to control which id tokens are * accepted. By default, the id token must have been issued to this OAuth2 client. * * @param $id_token * @param $audience * @return Google_LoginTicket */ public function verifyIdToken($id_token = null, $audience = null) { if (!$id_token) { $id_token = $this->token['id_token']; } $certs = $this->getFederatedSignonCerts(); if (!$audience) { $audience = $this->clientId; } return $this->verifySignedJwtWithCerts($id_token, $certs, $audience); } // Verifies the id token, returns the verified token contents. // Visible for testing. function verifySignedJwtWithCerts($jwt, $certs, $required_audience) { $segments = explode(".", $jwt); if (count($segments) != 3) { throw new Google_AuthException("Wrong number of segments in token: $jwt"); } $signed = $segments[0] . "." . $segments[1]; $signature = Google_Utils::urlSafeB64Decode($segments[2]); // Parse envelope. $envelope = json_decode(Google_Utils::urlSafeB64Decode($segments[0]), true); if (!$envelope) { throw new Google_AuthException("Can't parse token envelope: " . $segments[0]); } // Parse token $json_body = Google_Utils::urlSafeB64Decode($segments[1]); $payload = json_decode($json_body, true); if (!$payload) { throw new Google_AuthException("Can't parse token payload: " . $segments[1]); } // Check signature $verified = false; foreach ($certs as $keyName => $pem) { $public_key = new Google_PemVerifier($pem); if ($public_key->verify($signed, $signature)) { $verified = true; break; } } if (!$verified) { throw new Google_AuthException("Invalid token signature: $jwt"); } // Check issued-at timestamp $iat = 0; if (array_key_exists("iat", $payload)) { $iat = $payload["iat"]; } if (!$iat) { throw new Google_AuthException("No issue time in token: $json_body"); } $earliest = $iat - self::CLOCK_SKEW_SECS; // Check expiration timestamp $now = time(); $exp = 0; if (array_key_exists("exp", $payload)) { $exp = $payload["exp"]; } if (!$exp) { throw new Google_AuthException("No expiration time in token: $json_body"); } if ($exp >= $now + self::MAX_TOKEN_LIFETIME_SECS) { throw new Google_AuthException( "Expiration time too far in future: $json_body"); } $latest = $exp + self::CLOCK_SKEW_SECS; if ($now < $earliest) { throw new Google_AuthException( "Token used too early, $now < $earliest: $json_body"); } if ($now > $latest) { throw new Google_AuthException( "Token used too late, $now > $latest: $json_body"); } // TODO(beaton): check issuer field? // Check audience $aud = $payload["aud"]; if ($aud != $required_audience) { throw new Google_AuthException("Wrong recipient, $aud != $required_audience: $json_body"); } // All good. return new Google_LoginTicket($envelope, $payload); } }