diff options
Diffstat (limited to 'library/openid/provider/provider.php')
| -rw-r--r-- | library/openid/provider/provider.php | 845 |
1 files changed, 845 insertions, 0 deletions
diff --git a/library/openid/provider/provider.php b/library/openid/provider/provider.php new file mode 100644 index 000000000..03fbe1c81 --- /dev/null +++ b/library/openid/provider/provider.php @@ -0,0 +1,845 @@ +<?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(); + } + } +} |