<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_OpenId

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: OpenId.php 22653 2010-07-22 18:41:39Z mabe $

 */

/**

 * @see Zend_Controller_Response_Abstract

 */

require_once "Zend/Controller/Response/Abstract.php";

/**

 * Static class that contains common utility functions for

 * {@link Zend_OpenId_Consumer} and {@link Zend_OpenId_Provider}.

 *

 * This class implements common utility functions that are used by both

 * Consumer and Provider. They include functions for Diffie-Hellman keys

 * generation and exchange, URL normalization, HTTP redirection and some others.

 *

 * @category   Zend

 * @package    Zend_OpenId

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_OpenId

{

    /**

     * Default Diffie-Hellman key generator (1024 bit)

     */

    const DH_P   = 'dcf93a0b883972ec0e19989ac5a2ce310e1d37717e8d9571bb7623731866e61ef75a2e27898b057f9891c2e27a639c3f29b60814581cd3b2ca3986d2683705577d45c2e7e52dc81c7a171876e5cea74b1448bfdfaf18828efd2519f14e45e3826634af1949e5b535cc829a483b8a76223e5d490a257f05bdff16f2fb22c583ab';

    /**

     * Default Diffie-Hellman prime number (should be 2 or 5)

     */

    const DH_G   = '02';

    /**

     * OpenID 2.0 namespace. All OpenID 2.0 messages MUST contain variable

     * openid.ns with its value.

     */

    const NS_2_0 = 'http://specs.openid.net/auth/2.0';

    /**

     * Allows enable/disable stoping execution of PHP script after redirect()

     */

    static public $exitOnRedirect = true;

    /**

     * Alternative request URL that can be used to override the default

     * selfUrl() response

     */

    static public $selfUrl = null;

    /**

     * Sets alternative request URL that can be used to override the default

     * selfUrl() response

     *

     * @param string $selfUrl the URL to be set

     * @return string the old value of overriding URL

     */

    static public function setSelfUrl($selfUrl = null)

    {

        $ret = self::$selfUrl;

        self::$selfUrl = $selfUrl;

        return $ret;

    }

    /**

     * Returns a full URL that was requested on current HTTP request.

     *

     * @return string

     */

    static public function selfUrl()

    {

        if (self::$selfUrl !== null) {

            return self::$selfUrl;

        } if (isset($_SERVER['SCRIPT_URI'])) {

            return $_SERVER['SCRIPT_URI'];

        }

        $url = '';

        $port = '';

        if (isset($_SERVER['HTTP_HOST'])) {

            if (($pos = strpos($_SERVER['HTTP_HOST'], ':')) === false) {

                if (isset($_SERVER['SERVER_PORT'])) {

                    $port = ':' . $_SERVER['SERVER_PORT'];

                }

                $url = $_SERVER['HTTP_HOST'];

            } else {

                $url = substr($_SERVER['HTTP_HOST'], 0, $pos);

                $port = substr($_SERVER['HTTP_HOST'], $pos);

            }

        } else if (isset($_SERVER['SERVER_NAME'])) {

            $url = $_SERVER['SERVER_NAME'];

            if (isset($_SERVER['SERVER_PORT'])) {

                $port = ':' . $_SERVER['SERVER_PORT'];

            }

        }

        if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') {

            $url = 'https://' . $url;

            if ($port == ':443') {

                $port = '';

            }

        } else {

            $url = 'http://' . $url;

            if ($port == ':80') {

                $port = '';

            }

        }

        $url .= $port;

        if (isset($_SERVER['HTTP_X_REWRITE_URL'])) {

            $url .= $_SERVER['HTTP_X_REWRITE_URL'];

        } elseif (isset($_SERVER['REQUEST_URI'])) {

            $query = strpos($_SERVER['REQUEST_URI'], '?');

            if ($query === false) {

                $url .= $_SERVER['REQUEST_URI'];

            } else {

                $url .= substr($_SERVER['REQUEST_URI'], 0, $query);

            }

        } else if (isset($_SERVER['SCRIPT_URL'])) {

            $url .= $_SERVER['SCRIPT_URL'];

        } else if (isset($_SERVER['REDIRECT_URL'])) {

            $url .= $_SERVER['REDIRECT_URL'];

        } else if (isset($_SERVER['PHP_SELF'])) {

            $url .= $_SERVER['PHP_SELF'];

        } else if (isset($_SERVER['SCRIPT_NAME'])) {

            $url .= $_SERVER['SCRIPT_NAME'];

            if (isset($_SERVER['PATH_INFO'])) {

                $url .= $_SERVER['PATH_INFO'];

            }

        }

        return $url;

    }

    /**

     * Returns an absolute URL for the given one

     *

     * @param string $url absilute or relative URL

     * @return string

     */

    static public function absoluteUrl($url)

    {

        if (empty($url)) {

            return Zend_OpenId::selfUrl();

        } else if (!preg_match('|^([^:]+)://|', $url)) {

            if (preg_match('|^([^:]+)://([^:@]*(?:[:][^@]*)?@)?([^/:@?#]*)(?:[:]([^/?#]*))?(/[^?]*)?((?:[?](?:[^#]*))?(?:#.*)?)$|', Zend_OpenId::selfUrl(), $reg)) {

                $scheme = $reg[1];

                $auth = $reg[2];

                $host = $reg[3];

                $port = $reg[4];

                $path = $reg[5];

                $query = $reg[6];

                if ($url[0] == '/') {

                    return $scheme

                        . '://'

                        . $auth

                        . $host

                        . (empty($port) ? '' : (':' . $port))

                        . $url;

                } else {

                    $dir = dirname($path);

                    return $scheme

                        . '://'

                        . $auth

                        . $host

                        . (empty($port) ? '' : (':' . $port))

                        . (strlen($dir) > 1 ? $dir : '')

                        . '/'

                        . $url;

                }

            }

        }

        return $url;

    }

    /**

     * Converts variable/value pairs into URL encoded query string

     *

     * @param array $params variable/value pairs

     * @return string URL encoded query string

     */

    static public function paramsToQuery($params)

    {

        foreach($params as $key => $value) {

            if (isset($query)) {

                $query .= '&' . $key . '=' . urlencode($value);

            } else {

                $query = $key . '=' . urlencode($value);

            }

        }

        return isset($query) ? $query : '';

    }

    /**

     * Normalizes URL according to RFC 3986 to use it in comparison operations.

     * The function gets URL argument by reference and modifies it.

     * It returns true on success and false of failure.

     *

     * @param string &$id url to be normalized

     * @return bool

     */

    static public function normalizeUrl(&$id)

    {

        // RFC 3986, 6.2.2.  Syntax-Based Normalization

        // RFC 3986, 6.2.2.2 Percent-Encoding Normalization

        $i = 0;

        $n = strlen($id);

        $res = '';

        while ($i < $n) {

            if ($id[$i] == '%') {

                if ($i + 2 >= $n) {

                    return false;

                }

                ++$i;

                if ($id[$i] >= '0' && $id[$i] <= '9') {

                    $c = ord($id[$i]) - ord('0');

                } else if ($id[$i] >= 'A' && $id[$i] <= 'F') {

                    $c = ord($id[$i]) - ord('A') + 10;

                } else if ($id[$i] >= 'a' && $id[$i] <= 'f') {

                    $c = ord($id[$i]) - ord('a') + 10;

                } else {

                    return false;

                }

                ++$i;

                if ($id[$i] >= '0' && $id[$i] <= '9') {

                    $c = ($c << 4) | (ord($id[$i]) - ord('0'));

                } else if ($id[$i] >= 'A' && $id[$i] <= 'F') {

                    $c = ($c << 4) | (ord($id[$i]) - ord('A') + 10);

                } else if ($id[$i] >= 'a' && $id[$i] <= 'f') {

                    $c = ($c << 4) | (ord($id[$i]) - ord('a') + 10);

                } else {

                    return false;

                }

                ++$i;

                $ch = chr($c);

                if (($ch >= 'A' && $ch <= 'Z') ||

                    ($ch >= 'a' && $ch <= 'z') ||

                    $ch == '-' ||

                    $ch == '.' ||

                    $ch == '_' ||

                    $ch == '~') {

                    $res .= $ch;

                } else {

                    $res .= '%';

                    if (($c >> 4) < 10) {

                        $res .= chr(($c >> 4) + ord('0'));

                    } else {

                        $res .= chr(($c >> 4) - 10 + ord('A'));

                    }

                    $c = $c & 0xf;

                    if ($c < 10) {

                        $res .= chr($c + ord('0'));

                    } else {

                        $res .= chr($c - 10 + ord('A'));

                    }

                }

            } else {

                $res .= $id[$i++];

            }

        }

        if (!preg_match('|^([^:]+)://([^:@]*(?:[:][^@]*)?@)?([^/:@?#]*)(?:[:]([^/?#]*))?(/[^?#]*)?((?:[?](?:[^#]*))?)((?:#.*)?)$|', $res, $reg)) {

            return false;

        }

        $scheme = $reg[1];

        $auth = $reg[2];

        $host = $reg[3];

        $port = $reg[4];

        $path = $reg[5];

        $query = $reg[6];

        $fragment = $reg[7]; /* strip it */

        if (empty($scheme) || empty($host)) {

            return false;

        }

        // RFC 3986, 6.2.2.1.  Case Normalization

        $scheme = strtolower($scheme);

        $host = strtolower($host);

        // RFC 3986, 6.2.2.3.  Path Segment Normalization

        if (!empty($path)) {

            $i = 0;

            $n = strlen($path);

            $res = "";

            while ($i < $n) {

                if ($path[$i] == '/') {

                    ++$i;

                    while ($i < $n && $path[$i] == '/') {

                        ++$i;

                    }

                    if ($i < $n && $path[$i] == '.') {

                        ++$i;

                        if ($i < $n && $path[$i] == '.') {

                            ++$i;

                            if ($i == $n || $path[$i] == '/') {

                                if (($pos = strrpos($res, '/')) !== false) {

                                    $res = substr($res, 0, $pos);

                                }

                            } else {

                                    $res .= '/..';

                            }

                        } else if ($i != $n && $path[$i] != '/') {

                            $res .= '/.';

                        }

                    } else {

                        $res .= '/';

                    }

                } else {

                    $res .= $path[$i++];

                }

            }

            $path = $res;

        }

        // RFC 3986,6.2.3.  Scheme-Based Normalization

        if ($scheme == 'http') {

            if ($port == 80) {

                $port = '';

            }

        } else if ($scheme == 'https') {

            if ($port == 443) {

                $port = '';

            }

        }

        if (empty($path)) {

            $path = '/';

        }

        $id = $scheme

            . '://'

            . $auth

            . $host

            . (empty($port) ? '' : (':' . $port))

            . $path

            . $query;

        return true;

    }

    /**

     * Normalizes OpenID identifier that can be URL or XRI name.

     * Returns true on success and false of failure.

     *

     * Normalization is performed according to the following rules:

     * 1. If the user's input starts with one of the "xri://", "xri://$ip*",

     *    or "xri://$dns*" prefixes, they MUST be stripped off, so that XRIs

     *    are used in the canonical form, and URI-authority XRIs are further

     *    considered URL identifiers.

     * 2. If the first character of the resulting string is an XRI Global

     *    Context Symbol ("=", "@", "+", "$", "!"), then the input SHOULD be

     *    treated as an XRI.

     * 3. Otherwise, the input SHOULD be treated as an http URL; if it does

     *    not include a "http" or "https" scheme, the Identifier MUST be

     *    prefixed with the string "http://".

     * 4. URL identifiers MUST then be further normalized by both following

     *    redirects when retrieving their content and finally applying the

     *    rules in Section 6 of [RFC3986] to the final destination URL.

     * @param string &$id identifier to be normalized

     * @return bool

     */

    static public function normalize(&$id)

    {

        $id = trim($id);

        if (strlen($id) === 0) {

            return true;

        }

        // 7.2.1

        if (strpos($id, 'xri://$ip*') === 0) {

            $id = substr($id, strlen('xri://$ip*'));

        } else if (strpos($id, 'xri://$dns*') === 0) {

            $id = substr($id, strlen('xri://$dns*'));

        } else if (strpos($id, 'xri://') === 0) {

            $id = substr($id, strlen('xri://'));

        }

        // 7.2.2

        if ($id[0] == '=' ||

            $id[0] == '@' ||

            $id[0] == '+' ||

            $id[0] == '$' ||

            $id[0] == '!') {

            return true;

        }

        // 7.2.3

        if (strpos($id, "://") === false) {

            $id = 'http://' . $id;

        }

        // 7.2.4

        return self::normalizeURL($id);

    }