/scotlandyardphp/openid/provider/provider.php
PHP | 845 lines | 547 code | 102 blank | 196 comment | 90 complexity | 598f1213e34ca38d403d32b4d00ae727 MD5 | raw file
Possible License(s): GPL-2.0
- <?php
- /**
- * Using this class, you can easily set up an OpenID Provider.
- * It's independent of LightOpenID class.
- * It requires either GMP or BCMath for session encryption,
- * but will work without them (although either via SSL, or in stateless mode only).
- * Also, it requires PHP >= 5.1.2
- *
- * This is an alpha version, using it in production code is not recommended,
- * until you are *sure* that it works and is secure.
- *
- * Please send me messages about your testing results
- * (even if successful, so I know that it has been tested).
- * Also, if you think there's a way to make it easier to use, tell me -- it's an alpha for a reason.
- * Same thing applies to bugs in code, suggestions,
- * and everything else you'd like to say about the library.
- *
- * There's no usage documentation here, see the examples.
- *
- * @author Mewp
- * @copyright Copyright (c) 2010, Mewp
- * @license http://www.opensource.org/licenses/mit-license.php MIT
- */
- ini_set('error_log','log');
- abstract class LightOpenIDProvider
- {
- # URL-s to XRDS and server location.
- public $xrdsLocation, $serverLocation;
-
- # Should we operate in server, or signon mode?
- public $select_id = false;
-
- # Lifetime of an association.
- protected $assoc_lifetime = 600;
-
- # Variables below are either set automatically, or are constant.
- # -----
- # Can we support DH?
- protected $dh = true;
- protected $ns = 'http://specs.openid.net/auth/2.0';
- protected $data, $assoc;
-
- # Default DH parameters as defined in the specification.
- protected $default_modulus;
- protected $default_gen = 'Ag==';
-
- # AX <-> SREG transform
- protected $ax_to_sreg = array(
- 'namePerson/friendly' => 'nickname',
- 'contact/email' => 'email',
- 'namePerson' => 'fullname',
- 'birthDate' => 'dob',
- 'person/gender' => 'gender',
- 'contact/postalCode/home' => 'postcode',
- 'contact/country/home' => 'country',
- 'pref/language' => 'language',
- 'pref/timezone' => 'timezone',
- );
-
- # Math
- private $add, $mul, $pow, $mod, $div, $powmod;
- # -----
-
- # ------------------------------------------------------------------------ #
- # Functions you probably want to implement when extending the class.
-
- /**
- * Checks whether an user is authenticated.
- * The function should determine what fields it wants to send to the RP,
- * and put them in the $attributes array.
- * @param Array $attributes
- * @param String $realm Realm used for authentication.
- * @return String OP-local identifier of an authenticated user, or an empty value.
- */
- abstract function checkid($realm, &$attributes);
-
- /**
- * Displays an user interface for inputting user's login and password.
- * Attributes are always AX field namespaces, with stripped host part.
- * For example, the $attributes array may be:
- * array( 'required' => array('namePerson/friendly', 'contact/email'),
- * 'optional' => array('pref/timezone', 'pref/language')
- * @param String $identity Discovered identity string. May be used to extract login, unless using $this->select_id
- * @param String $realm Realm used for authentication.
- * @param String Association handle. must be sent as openid.assoc_handle in $_GET or $_POST in subsequent requests.
- * @param Array User attributes requested by the RP.
- */
- abstract function setup($identity, $realm, $assoc_handle, $attributes);
-
- /**
- * Stores an association.
- * If you want to use php sessions in your provider code, you have to replace it.
- * @param String $handle Association handle -- should be used as a key.
- * @param Array $assoc Association data.
- */
- protected function setAssoc($handle, $assoc)
- {
- $oldSession = session_id();
- session_commit();
- session_id($assoc['handle']);
- session_start();
- $_SESSION['assoc'] = $assoc;
- session_commit();
- if($oldSession) {
- session_id($oldSession);
- session_start();
- }
- }
-
- /**
- * Retreives association data.
- * If you want to use php sessions in your provider code, you have to replace it.
- * @param String $handle Association handle.
- * @return Array Association data.
- */
- protected function getAssoc($handle)
- {
- $oldSession = session_id();
- session_commit();
- session_id($handle);
- session_start();
- if(empty($_SESSION['assoc'])) {
- return null;
- }
- return $_SESSION['assoc'];
- session_commit();
- if($oldSession) {
- session_id($oldSession);
- session_start();
- }
- }
-
- /**
- * Deletes an association.
- * If you want to use php sessions in your provider code, you have to replace it.
- * @param String $handle Association handle.
- */
- protected function delAssoc($handle)
- {
- $oldSession = session_id();
- session_commit();
- session_id($handle);
- session_start();
- session_destroy();
- if($oldSession) {
- session_id($oldSession);
- session_start();
- }
- }
-
- # ------------------------------------------------------------------------ #
- # Functions that you might want to implement.
-
- /**
- * Redirects the user to an url.
- * @param String $location The url that the user will be redirected to.
- */
- protected function redirect($location)
- {
- header('Location: ' . $location);
- die();
- }
-
- /**
- * Generates a new association handle.
- * @return string
- */
- protected function assoc_handle()
- {
- return sha1(microtime());
- }
-
- /**
- * Generates a random shared secret.
- * @return string
- */
- protected function shared_secret($hash)
- {
- $length = 20;
- if($hash == 'sha256') {
- $length = 256;
- }
-
- $secret = '';
- for($i = 0; $i < $length; $i++) {
- $secret .= mt_rand(0,255);
- }
-
- return $secret;
- }
-
- /**
- * Generates a private key.
- * @param int $length Length of the key.
- */
- protected function keygen($length)
- {
- $key = '';
- for($i = 1; $i < $length; $i++) {
- $key .= mt_rand(0,9);
- }
- $key .= mt_rand(1,9);
-
- return $key;
- }
-
- # ------------------------------------------------------------------------ #
- # Functions that you probably shouldn't touch.
-
- function __construct()
- {
- $this->default_modulus =
- 'ANz5OguIOXLsDhmYmsWizjEOHTdxfo2Vcbt2I3MYZuYe91ouJ4mLBX+YkcLiemOcPy'
- . 'm2CBRYHNOyyjmG0mg3BVd9RcLn5S3IHHoXGHblzqdLFEi/368Ygo79JRnxTkXjgmY0'
- . 'rxlJ5bU1zIKaSDuKdiI+XUkKJX8Fvf8W8vsixYOr';
- $location = (!empty($_SERVER['HTTPS']) ? 'https' : 'http') . '://'
- . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
- $location = preg_replace('/\?.*/','',$location);
- $this->serverLocation = $location;
- $location .= (strpos($location, '?') ? '&' : '?') . 'xrds';
- $this->xrdsLocation = $location;
-
- $this->data = $_GET + $_POST;
-
- # We choose GMP if avaiable, and bcmath otherwise
- if(function_exists('gmp_add')) {
- $this->add = 'gmp_add';
- $this->mul = 'gmp_mul';
- $this->pow = 'gmp_pow';
- $this->mod = 'gmp_mod';
- $this->div = 'gmp_div';
- $this->powmod = 'gmp_powm';
- } elseif(function_exists('bcadd')) {
- $this->add = 'bcadd';
- $this->mul = 'bcmul';
- $this->pow = 'bcpow';
- $this->mod = 'bcmod';
- $this->div = 'bcdiv';
- $this->powmod = 'bcpowmod';
- } else {
- # If neither are avaiable, we can't use DH
- $this->dh = false;
- }
-
- # However, we do require the hash functions.
- # They should be built-in anyway.
- if(!function_exists('hash_algos')) {
- $this->dh = false;
- }
- }
-
- /**
- * Displays an XRDS document, or redirects to it.
- * By default, it detects whether it should display or redirect automatically.
- * @param bool|null $force When true, always display the document, when false always redirect.
- */
- function xrds($force=null)
- {
- if($force) {
- echo $this->xrdsContent();
- die();
- } elseif($force === false) {
- header('X-XRDS-Location: '. $this->xrdsLocation);
- return;
- }
-
- if (isset($_GET['xrds'])
- || (isset($_SERVER['HTTP_ACCEPT']) && strpos($_SERVER['HTTP_ACCEPT'], 'application/xrds+xml') !== false)
- ) {
- header('Content-Type: application/xrds+xml');
- echo $this->xrdsContent();
- die();
- }
-
- header('X-XRDS-Location: ' . $this->xrdsLocation);
- }
-
- /**
- * Returns the content of the XRDS document
- * @return String The XRDS document.
- */
- protected function xrdsContent()
- {
- $lines = array(
- '<?xml version="1.0" encoding="UTF-8"?>',
- '<xrds:XRDS xmlns:xrds="xri://$xrds" xmlns="xri://$xrd*($v*2.0)">',
- '<XRD>',
- ' <Service>',
- ' <Type>' . $this->ns . '/' . ($this->select_id ? 'server' : 'signon') .'</Type>',
- ' <URI>' . $this->serverLocation . '</URI>',
- ' </Service>',
- '</XRD>',
- '</xrds:XRDS>'
- );
- return implode("\n", $lines);
- }
-
- /**
- * Does everything that a provider has to -- in one function.
- */
- function server()
- {
- if(isset($this->data['openid_assoc_handle'])) {
- $this->assoc = $this->getAssoc($this->data['openid_assoc_handle']);
- if(isset($this->assoc['data'])) {
- # We have additional data stored for setup.
- $this->data += $this->assoc['data'];
- unset($this->assoc['data']);
- }
- }
-
- if (isset($this->data['openid_ns'])
- && $this->data['openid_ns'] == $this->ns
- ) {
- if(!isset($this->data['openid_mode'])) $this->errorResponse();
-
- switch($this->data['openid_mode'])
- {
- case 'checkid_immediate':
- case 'checkid_setup':
- $this->checkRealm();
- # We support AX xor SREG.
- $attributes = $this->ax();
- if(!$attributes) {
- $attributes = $this->sreg();
- }
-
- # Even if some user is authenticated, we need to know if it's
- # the same one that want's to authenticate.
- # Of course, if we use select_id, we accept any user.
- if (($identity = $this->checkid($this->data['openid_realm'], $attrValues))
- && ($this->select_id || $identity == $this->data['openid_identity'])
- ) {
- $this->positiveResponse($identity, $attrValues);
- } elseif($this->data['openid_mode'] == 'checkid_immediate') {
- $this->redirect($this->response(array('openid.mode' => 'setup_needed')));
- } else {
- if(!$this->assoc) {
- $this->generateAssociation();
- $this->assoc['private'] = true;
- }
- $this->assoc['data'] = $this->data;
- $this->setAssoc($this->assoc['handle'], $this->assoc);
- $this->setup($this->data['openid_identity'],
- $this->data['openid_realm'],
- $this->assoc['handle'],
- $attributes);
- }
- break;
- case 'associate':
- $this->associate();
- break;
- case 'check_authentication':
- $this->checkRealm();
- if($this->verify()) {
- echo "ns:$this->ns\nis_valid:true";
- if(strpos($this->data['openid_signed'],'invalidate_handle') !== false) {
- echo "\ninvalidate_handle:" . $this->data['openid_invalidate_handle'];
- }
- } else {
- echo "ns:$this->ns\nis_valid:false";
- }
- die();
- break;
- default:
- $this->errorResponse();
- }
- } else {
- $this->xrds();
- }
- }
-
- protected function checkRealm()
- {
- if (!isset($this->data['openid_return_to'], $this->data['openid_realm'])) {
- $this->errorResponse();
- }
-
- $realm = str_replace('\*', '[^/]', preg_quote($this->data['openid_realm']));
- if(!preg_match("#^$realm#", $this->data['openid_return_to'])) {
- $this->errorResponse();
- }
- }
-
- protected function ax()
- {
- # Namespace prefix that the fields must have.
- $ns = 'http://axschema.org/';
-
- # First, we must find out what alias is used for AX.
- # Let's check the most likely one
- $alias = null;
- if (isset($this->data['openid_ns_ax'])
- && $this->data['openid_ns_ax'] == 'http://openid.net/srv/ax/1.0'
- ) {
- $alias = 'ax';
- } else {
- foreach($this->data as $name => $value) {
- if ($value == 'http://openid.net/srv/ax/1.0'
- && preg_match('/openid_ns_(.+)/', $name, $m)
- ) {
- $alias = $m[1];
- break;
- }
- }
- }
-
- if(!$alias) {
- return null;
- }
-
- $fields = array();
- # Now, we must search again, this time for field aliases
- foreach($this->data as $name => $value) {
- if (strpos($name, 'openid_' . $alias . '_type') === false
- || strpos($value, $ns) === false) {
- continue;
- }
-
- $name = substr($name, strlen('openid_' . $alias . '_type_'));
- $value = substr($value, strlen($ns));
-
- $fields[$name] = $value;
- }
-
- # Then, we find out what fields are required and optional
- $required = array();
- $if_available = array();
- foreach(array('required','if_available') as $type) {
- if(empty($this->data["openid_{$alias}_{$type}"])) {
- continue;
- }
- $attributes = explode(',', $this->data["openid_{$alias}_{$type}"]);
- foreach($attributes as $attr) {
- if(empty($fields[$attr])) {
- # There is an undefined field here, so we ignore it.
- continue;
- }
-
- ${$type}[] = $fields[$attr];
- }
- }
-
- $this->data['ax'] = true;
- return array('required' => $required, 'optional' => $if_available);
- }
-
- protected function sreg()
- {
- $sreg_to_ax = array_flip($this->ax_to_sreg);
-
- $attributes = array('required' => array(), 'optional' => array());
-
- if (empty($this->data['openid_sreg_required'])
- && empty($this->data['openid_sreg_optional'])
- ) {
- return $attributes;
- }
-
- foreach(array('required', 'optional') as $type) {
- foreach(explode(',',$this->data['openid_sreg_' . $type]) as $attr) {
- if(empty($sreg_to_ax[$attr])) {
- # Undefined attribute in SREG request.
- # Shouldn't happen, but we check anyway.
- continue;
- }
-
- $attributes[$type][] = $sreg_to_ax[$attr];
- }
- }
-
- return $attributes;
- }
-
- /**
- * Aids an RP in assertion verification.
- * @return bool Information whether the verification suceeded.
- */
- protected function verify()
- {
- # Firstly, we need to make sure that there's an association.
- # Otherwise the verification will fail,
- # because we've signed assoc_handle in the assertion
- if(empty($this->assoc)) {
- return false;
- }
-
- # Next, we check that it's a private association,
- # i.e. one made without RP input.
- # Otherwise, the RP shouldn't ask us to verify.
- if(empty($this->assoc['private'])) {
- return false;
- }
-
- # Now we have to check if the nonce is correct, to prevent replay attacks.
- if($this->data['openid_response_nonce'] != $this->assoc['nonce']) {
- return false;
- }
-
- # Getting the signed fields for signature.
- $sig = array();
- $signed = explode(',', $this->data['openid_signed']);
- foreach($signed as $field) {
- $name = strtr($field, '.', '_');
- if(!isset($this->data['openid_' . $name])) {
- return false;
- }
-
- $sig[$field] = $this->data['openid_' . $name];
- }
-
- # Computing the signature and checking if it matches.
- $sig = $this->keyValueForm($sig);
- if ($this->data['openid_sig'] !=
- base64_encode(hash_hmac($this->assoc['hash'], $sig, $this->assoc['mac'], true))
- ) {
- return false;
- }
-
- # Clearing the nonce, so that it won't be used again.
- $this->assoc['nonce'] = null;
-
- if(empty($this->assoc['private'])) {
- # Commiting changes to the association.
- $this->setAssoc($this->assoc['handle'], $this->assoc);
- } else {
- # Private associations shouldn't be used again, se we can as well delete them.
- $this->delAssoc($this->assoc['handle']);
- }
-
- # Nothing has failed, so the verification was a success.
- return true;
- }
-
- /**
- * Performs association with an RP.
- */
- protected function associate()
- {
- # Rejecting no-encryption without TLS.
- if(empty($_SERVER['HTTPS']) && $this->data['openid_session_type'] == 'no-encryption') {
- $this->directErrorResponse();
- }
-
- # Checking whether we support DH at all.
- if (!$this->dh && substr($this->data['openid_session_type'], 0, 2) == 'DH') {
- $this->redirect($this->response(array(
- 'openid.error' => 'DH not supported',
- 'openid.error_code' => 'unsupported-type',
- 'openid.session_type' => 'no-encryption'
- )));
- }
-
- # Creating the association
- $this->assoc = array();
- $this->assoc['hash'] = $this->data['openid_assoc_type'] == 'HMAC-SHA256' ? 'sha256' : 'sha1';
- $this->assoc['handle'] = $this->assoc_handle();
-
- # Getting the shared secret
- if($this->data['openid_session_type'] == 'no-encryption') {
- $this->assoc['mac'] = base64_encode($this->shared_secret($this->assoc['hash']));
- } else {
- $this->dh();
- }
-
- # Preparing the direct response...
- $response = array(
- 'ns' => $this->ns,
- 'assoc_handle' => $this->assoc['handle'],
- 'assoc_type' => $this->data['openid_assoc_type'],
- 'session_type' => $this->data['openid_session_type'],
- 'expires_in' => $this->assoc_lifetime
- );
-
- if(isset($this->assoc['dh_server_public'])) {
- $response['dh_server_public'] = $this->assoc['dh_server_public'];
- $response['enc_mac_key'] = $this->assoc['mac'];
- } else {
- $response['mac_key'] = $this->assoc['mac'];
- }
-
- # ...and sending it.
- echo $this->keyValueForm($response);
- die();
- }
-
- /**
- * Creates a private association.
- */
- protected function generateAssociation()
- {
- $this->assoc = array();
- # We use sha1 by default.
- $this->assoc['hash'] = 'sha1';
- $this->assoc['mac'] = $this->shared_secret('sha1');
- $this->assoc['handle'] = $this->assoc_handle();
- }
-
- /**
- * Encrypts the MAC key using DH key exchange.
- */
- protected function dh()
- {
- if(empty($this->data['openid_dh_modulus'])) {
- $this->data['openid_dh_modulus'] = $this->default_modulus;
- }
-
- if(empty($this->data['openid_dh_gen'])) {
- $this->data['openid_dh_gen'] = $this->default_gen;
- }
-
- if(empty($this->data['openid_dh_consumer_public'])) {
- $this->directErrorResponse();
- }
-
- $modulus = $this->b64dec($this->data['openid_dh_modulus']);
- $gen = $this->b64dec($this->data['openid_dh_gen']);
- $consumerKey = $this->b64dec($this->data['openid_dh_consumer_public']);
-
- $privateKey = $this->keygen(strlen($modulus));
- $publicKey = $this->powmod($gen, $privateKey, $modulus);
- $ss = $this->powmod($consumerKey, $privateKey, $modulus);
-
- $mac = $this->x_or(hash($this->assoc['hash'], $ss, true), $this->shared_secret($this->assoc['hash']));
- $this->assoc['dh_server_public'] = $this->decb64($publicKey);
- $this->assoc['mac'] = base64_encode($mac);
- }
-
- /**
- * XORs two strings.
- * @param String $a
- * @param String $b
- * @return String $a ^ $b
- */
- protected function x_or($a, $b)
- {
- $length = strlen($a);
- for($i = 0; $i < $length; $i++) {
- $a[$i] = $a[$i] ^ $b[$i];
- }
-
- return $a;
- }
-
- /**
- * Prepares an indirect response url.
- * @param array $params Parameters to be sent.
- */
- protected function response($params)
- {
- $params += array('openid.ns' => $this->ns);
- return $this->data['openid_return_to']
- . (strpos($this->data['openid_return_to'],'?') ? '&' : '?')
- . http_build_query($params, '', '&');
- }
-
- /**
- * Outputs a direct error.
- */
- protected function errorResponse()
- {
- if(!empty($this->data['openid_return_to'])) {
- $response = array(
- 'openid.mode' => 'error',
- 'openid.error' => 'Invalid request'
- );
- $this->redirect($this->response($response));
- } else {
- header('HTTP/1.1 400 Bad Request');
- $response = array(
- 'ns' => $this->ns,
- 'error' => 'Invalid request'
- );
- echo $this->keyValueForm($response);
- }
- die();
- }
-
- /**
- * Sends an positive assertion.
- * @param String $identity the OP-Local Identifier that is being authenticated.
- * @param Array $attributes User attributes to be sent.
- */
- protected function positiveResponse($identity, $attributes)
- {
- # We generate a private association if there is none established.
- if(!$this->assoc) {
- $this->generateAssociation();
- $this->assoc['private'] = true;
- }
-
- # We set openid.identity (and openid.claimed_id if necessary) to our $identity
- if($this->data['openid_identity'] == $this->data['openid_claimed_id'] || $this->select_id) {
- $this->data['openid_claimed_id'] = $identity;
- }
- $this->data['openid_identity'] = $identity;
-
- # Preparing fields to be signed
- $params = array(
- 'op_endpoint' => $this->serverLocation,
- 'claimed_id' => $this->data['openid_claimed_id'],
- 'identity' => $this->data['openid_identity'],
- 'return_to' => $this->data['openid_return_to'],
- 'realm' => $this->data['openid_realm'],
- 'response_nonce' => gmdate("Y-m-d\TH:i:s\Z"),
- 'assoc_handle' => $this->assoc['handle'],
- );
-
- $params += $this->responseAttributes($attributes);
-
- # Has the RP used an invalid association handle?
- if (isset($this->data['openid_assoc_handle'])
- && $this->data['openid_assoc_handle'] != $this->assoc['handle']
- ) {
- $params['invalidate_handle'] = $this->data['openid_assoc_handle'];
- }
-
- # Signing the $params
- $sig = hash_hmac($this->assoc['hash'], $this->keyValueForm($params), $this->assoc['mac'], true);
- $req = array(
- 'openid.mode' => 'id_res',
- 'openid.signed' => implode(',', array_keys($params)),
- 'openid.sig' => base64_encode($sig),
- );
-
- # Saving the nonce and commiting the association.
- $this->assoc['nonce'] = $params['response_nonce'];
- $this->setAssoc($this->assoc['handle'], $this->assoc);
-
- # Preparing and sending the response itself
- foreach($params as $name => $value) {
- $req['openid.' . $name] = $value;
- }
-
- $this->redirect($this->response($req));
- }
-
- /**
- * Prepares an array of attributes to send
- */
- protected function responseAttributes($attributes)
- {
- if(!$attributes) return array();
-
- $ns = 'http://axschema.org/';
- $response = array();
- if(isset($this->data['ax'])) {
- $response['ns.ax'] = 'http://openid.net/srv/ax/1.0';
- foreach($attributes as $name => $value) {
- $alias = strtr($name, '/', '_');
- $response['ax.type.' . $alias] = $ns . $name;
- $response['ax.value.' . $alias] = $value;
- }
- return $response;
- }
-
- foreach($attributes as $name => $value) {
- if(!isset($this->ax_to_sreg[$name])) {
- continue;
- }
-
- $response['sreg.' . $this->ax_to_sreg[$name]] = $value;
- }
- return $response;
- }
-
- /**
- * Encodes fields in key-value form.
- * @param Array $params Fields to be encoded.
- * @return String $params in key-value form.
- */
- protected function keyValueForm($params)
- {
- $str = '';
- foreach($params as $name => $value) {
- $str .= "$name:$value\n";
- }
-
- return $str;
- }
-
- /**
- * Responds with an information that the user has canceled authentication.
- */
- protected function cancel()
- {
- $this->redirect($this->response(array('openid.mode' => 'cancel')));
- }
-
- /**
- * Converts base64 encoded number to it's decimal representation.
- * @param String $str base64 encoded number.
- * @return String Decimal representation of that number.
- */
- protected function b64dec($str)
- {
- $bytes = unpack('C*', base64_decode($str));
- $n = 0;
- foreach($bytes as $byte) {
- $n = $this->add($this->mul($n, 256), $byte);
- }
-
- return $n;
- }
-
- /**
- * Complements b64dec.
- */
- protected function decb64($num)
- {
- $bytes = array();
- while($num) {
- array_unshift($bytes, $this->mod($num, 256));
- $num = $this->div($num, 256);
- }
-
- if($bytes && $bytes[0] > 127) {
- array_unshift($bytes,0);
- }
-
- array_unshift($bytes, 'C*');
-
- return base64_encode(call_user_func_array('pack', $bytes));
- }
-
- function __call($name, $args)
- {
- switch($name) {
- case 'add':
- case 'mul':
- case 'pow':
- case 'mod':
- case 'div':
- case 'powmod':
- if(function_exists('gmp_strval')) {
- return gmp_strval(call_user_func_array($this->$name, $args));
- }
- return call_user_func_array($this->$name, $args);
- default:
- throw new BadMethodCallException();
- }
- }
- }