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<?php
/**
* Functions for dealing with OpenID trust roots
*
* PHP versions 4 and 5
*
* LICENSE: See the COPYING file included in this distribution.
*
* @package OpenID
* @author JanRain, Inc. <openid@janrain.com>
* @copyright 2005 Janrain, Inc.
* @license http://www.gnu.org/copyleft/lesser.html LGPL
*/
/**
* 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|' .
'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 {
/**
* 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']);
if (substr($path, -1) != '/') {
$path .= '/';
}
} else {
$path = '/';
}
$parts['path'] = $path;
if (!isset($parts['port'])) {
$parts['port'] = false;
}
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']);
}
}
?>