* @copyright 2005 Janrain, Inc. * @license http://www.gnu.org/copyleft/lesser.html LGPL */ require_once 'Auth/OpenID/Discover.php'; /** * A regular expression that matches a domain ending in a top-level domains. * Used in checking trust roots for sanity. * * @access private */ define('Auth_OpenID___TLDs', '/\.(com|edu|gov|int|mil|net|org|biz|info|name|museum|coop|aero|ac|' . 'ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|az|ba|bb|bd|be|bf|bg|' . 'bh|bi|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|' . 'cm|cn|co|cr|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|ee|eg|eh|er|es|et|eu|' . 'fi|fj|fk|fm|fo|fr|ga|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|' . 'gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|iq|ir|is|it|je|jm|jo|jp|' . 'ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|' . 'ma|mc|md|mg|mh|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|my|mz|na|' . 'nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|' . 'ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|' . 'so|sr|st|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|' . 'ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)$/'); /** * A wrapper for trust-root related functions */ class Auth_OpenID_TrustRoot { /* * Return a discovery URL for this realm. * * Return null if the realm could not be parsed or was not valid. * * @param return_to The relying party return URL of the OpenID * authentication request * * @return The URL upon which relying party discovery should be * run in order to verify the return_to URL */ function buildDiscoveryURL($realm) { $parsed = Auth_OpenID_TrustRoot::_parse($realm); if ($parsed === false) { return false; } if ($parsed['wildcard']) { // Use "www." in place of the star if ($parsed['host'][0] != '.') { return false; } $www_domain = 'www' . $parsed['host']; return sprintf('%s://%s%s', $parsed['scheme'], $www_domain, $parsed['path']); } else { return $parsed['unparsed']; } } /** * Parse a URL into its trust_root parts. * * @static * * @access private * * @param string $trust_root The url to parse * * @return mixed $parsed Either an associative array of trust root * parts or false if parsing failed. */ function _parse($trust_root) { $parts = @parse_url($trust_root); if ($parts === false) { return false; } $required_parts = array('scheme', 'host'); $forbidden_parts = array('user', 'pass', 'fragment'); $keys = array_keys($parts); if (array_intersect($keys, $required_parts) != $required_parts) { return false; } if (array_intersect($keys, $forbidden_parts) != array()) { return false; } // Return false if the original trust root value has more than // one port specification. if (preg_match("/:\/\/[^:]+(:\d+){2,}(\/|$)/", $trust_root)) { return false; } $scheme = strtolower($parts['scheme']); $allowed_schemes = array('http', 'https'); if (!in_array($scheme, $allowed_schemes)) { return false; } $parts['scheme'] = $scheme; $host = strtolower($parts['host']); $hostparts = explode('*', $host); switch (count($hostparts)) { case 1: $parts['wildcard'] = false; break; case 2: if ($hostparts[0] || ($hostparts[1] && substr($hostparts[1], 0, 1) != '.')) { return false; } $host = $hostparts[1]; $parts['wildcard'] = true; break; default: return false; } if (strpos($host, ':') !== false) { return false; } $parts['host'] = $host; if (isset($parts['path'])) { $path = strtolower($parts['path']); } else { $path = '/'; } $parts['path'] = $path; if (!isset($parts['port'])) { $parts['port'] = false; } $parts['unparsed'] = $trust_root; return $parts; } /** * Is this trust root sane? * * A trust root is sane if it is syntactically valid and it has a * reasonable domain name. Specifically, the domain name must be * more than one level below a standard TLD or more than two * levels below a two-letter tld. * * For example, '*.com' is not a sane trust root, but '*.foo.com' * is. '*.co.uk' is not sane, but '*.bbc.co.uk' is. * * This check is not always correct, but it attempts to err on the * side of marking sane trust roots insane instead of marking * insane trust roots sane. For example, 'kink.fm' is marked as * insane even though it "should" (for some meaning of should) be * marked sane. * * This function should be used when creating OpenID servers to * alert the users of the server when a consumer attempts to get * the user to accept a suspicious trust root. * * @static * @param string $trust_root The trust root to check * @return bool $sanity Whether the trust root looks OK */ function isSane($trust_root) { $parts = Auth_OpenID_TrustRoot::_parse($trust_root); if ($parts === false) { return false; } // Localhost is a special case if ($parts['host'] == 'localhost') { return true; } // Get the top-level domain of the host. If it is not a valid TLD, // it's not sane. preg_match(Auth_OpenID___TLDs, $parts['host'], $matches); if (!$matches) { return false; } $tld = $matches[1]; // Require at least two levels of specificity for non-country // tlds and three levels for country tlds. $elements = explode('.', $parts['host']); $n = count($elements); if ($parts['wildcard']) { $n -= 1; } if (strlen($tld) == 2) { $n -= 1; } if ($n <= 1) { return false; } return true; } /** * Does this URL match the given trust root? * * Return whether the URL falls under the given trust root. This * does not check whether the trust root is sane. If the URL or * trust root do not parse, this function will return false. * * @param string $trust_root The trust root to match against * * @param string $url The URL to check * * @return bool $matches Whether the URL matches against the * trust root */ function match($trust_root, $url) { $trust_root_parsed = Auth_OpenID_TrustRoot::_parse($trust_root); $url_parsed = Auth_OpenID_TrustRoot::_parse($url); if (!$trust_root_parsed || !$url_parsed) { return false; } // Check hosts matching if ($url_parsed['wildcard']) { return false; } if ($trust_root_parsed['wildcard']) { $host_tail = $trust_root_parsed['host']; $host = $url_parsed['host']; if ($host_tail && substr($host, -(strlen($host_tail))) != $host_tail && substr($host_tail, 1) != $host) { return false; } } else { if ($trust_root_parsed['host'] != $url_parsed['host']) { return false; } } // Check path and query matching $base_path = $trust_root_parsed['path']; $path = $url_parsed['path']; if (!isset($trust_root_parsed['query'])) { if (substr($path, 0, strlen($base_path)) != $base_path) { return false; } } else { $base_query = $trust_root_parsed['query']; $query = @$url_parsed['query']; $qplus = substr($query, 0, strlen($base_query) + 1); $bqplus = $base_query . '&'; if ($base_path != $path || ($base_query != $query && $qplus != $bqplus)) { return false; } } // The port and scheme need to match exactly return ($trust_root_parsed['scheme'] == $url_parsed['scheme'] && $url_parsed['port'] === $trust_root_parsed['port']); } } /* * If the endpoint is a relying party OpenID return_to endpoint, * return the endpoint URL. Otherwise, return None. * * This function is intended to be used as a filter for the Yadis * filtering interface. * * @see: C{L{openid.yadis.services}} * @see: C{L{openid.yadis.filters}} * * @param endpoint: An XRDS BasicServiceEndpoint, as returned by * performing Yadis dicovery. * * @returns: The endpoint URL or None if the endpoint is not a * relying party endpoint. */ function filter_extractReturnURL(&$endpoint) { if ($endpoint->matchTypes(array(Auth_OpenID_RP_RETURN_TO_URL_TYPE))) { return $endpoint; } else { return null; } } function &Auth_OpenID_extractReturnURL(&$endpoint_list) { $result = array(); foreach ($endpoint_list as $endpoint) { if (filter_extractReturnURL($endpoint)) { $result[] = $endpoint; } } return $result; } /* * Is the return_to URL under one of the supplied allowed return_to * URLs? */ function Auth_OpenID_returnToMatches($allowed_return_to_urls, $return_to) { foreach ($allowed_return_to_urls as $allowed_return_to) { // A return_to pattern works the same as a realm, except that // it's not allowed to use a wildcard. We'll model this by // parsing it as a realm, and not trying to match it if it has // a wildcard. $return_realm = Auth_OpenID_TrustRoot::_parse($allowed_return_to); if (// Parses as a trust root ($return_realm !== false) && // Does not have a wildcard (!$return_realm['wildcard']) && // Matches the return_to that we passed in with it (Auth_OpenID_TrustRoot::match($allowed_return_to, $return_to))) { return true; } } // No URL in the list matched return false; } /* * Given a relying party discovery URL return a list of return_to * URLs. */ function Auth_OpenID_getAllowedReturnURLs($relying_party_url, &$fetcher, $discover_function=null) { if ($discover_function === null) { $discover_function = array('Auth_Yadis_Yadis', 'discover'); } list($rp_url_after_redirects, $endpoints) = Auth_OpenID_discoverWithYadis($relying_party_url, $fetcher, 'Auth_OpenID_extractReturnURL', $discover_function); if ($rp_url_after_redirects != $relying_party_url) { // Verification caused a redirect return false; } $return_to_urls = array(); foreach ($endpoints as $e) { $return_to_urls[] = $e->server_url; } return $return_to_urls; } /* * Verify that a return_to URL is valid for the given realm. * * This function builds a discovery URL, performs Yadis discovery on * it, makes sure that the URL does not redirect, parses out the * return_to URLs, and finally checks to see if the current return_to * URL matches the return_to. * * @return true if the return_to URL is valid for the realm */ function Auth_OpenID_verifyReturnTo($realm_str, $return_to, &$fetcher, $_vrfy='Auth_OpenID_getAllowedReturnURLs') { $disco_url = Auth_OpenID_TrustRoot::buildDiscoveryURL($realm_str); if ($disco_url === false) { return false; } $allowable_urls = call_user_func_array($_vrfy, array($disco_url, &$fetcher)); // The realm_str could not be parsed. if ($allowable_urls === false) { return false; } if (Auth_OpenID_returnToMatches($allowable_urls, $return_to)) { return true; } else { return false; } } ?>