/src/auth/Google_OAuth2.php
PHP | 453 lines | 294 code | 56 blank | 103 comment | 64 complexity | acb231b360ef09762189f89776789982 MD5 | raw file
- <?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);
- }
- }