<?php
/**
 *  Base include file for SimpleTest
 *  @package    SimpleTest
 *  @subpackage WebTester
 *  @version    $Id: authentication.php,v 1.3 2013/02/02 11:38:59 andig2 Exp $
 */
/**
 *  include http class
 */
require_once(dirname(__FILE__) . '/http.php');

/**
 *    Represents a single security realm's identity.
 *    @package SimpleTest
 *    @subpackage WebTester
 */
class SimpleRealm {
    private $type;
    private $root;
    private $username;
    private $password;

    /**
     *    Starts with the initial entry directory.
     *    @param string $type      Authentication type for this
     *                             realm. Only Basic authentication
     *                             is currently supported.
     *    @param SimpleUrl $url    Somewhere in realm.
     *    @access public
     */
    function SimpleRealm($type, $url) {
        $this->type = $type;
        $this->root = $url->getBasePath();
        $this->username = false;
        $this->password = false;
    }

    /**
     *    Adds another location to the realm.
     *    @param SimpleUrl $url    Somewhere in realm.
     *    @access public
     */
    function stretch($url) {
        $this->root = $this->getCommonPath($this->root, $url->getPath());
    }

    /**
     *    Finds the common starting path.
     *    @param string $first        Path to compare.
     *    @param string $second       Path to compare.
     *    @return string              Common directories.
     *    @access private
     */
    protected function getCommonPath($first, $second) {
        $first = explode('/', $first);
        $second = explode('/', $second);
        for ($i = 0; $i < min(count($first), count($second)); $i++) {
            if ($first[$i] != $second[$i]) {
                return implode('/', array_slice($first, 0, $i)) . '/';
            }
        }
        return implode('/', $first) . '/';
    }

    /**
     *    Sets the identity to try within this realm.
     *    @param string $username    Username in authentication dialog.
     *    @param string $username    Password in authentication dialog.
     *    @access public
     */
    function setIdentity($username, $password) {
        $this->username = $username;
        $this->password = $password;
    }

    /**
     *    Accessor for current identity.
     *    @return string        Last succesful username.
     *    @access public
     */
    function getUsername() {
        return $this->username;
    }

    /**
     *    Accessor for current identity.
     *    @return string        Last succesful password.
     *    @access public
     */
    function getPassword() {
        return $this->password;
    }

    /**
     *    Test to see if the URL is within the directory
     *    tree of the realm.
     *    @param SimpleUrl $url    URL to test.
     *    @return boolean          True if subpath.
     *    @access public
     */
    function isWithin($url) {
        if ($this->isIn($this->root, $url->getBasePath())) {
            return true;
        }
        if ($this->isIn($this->root, $url->getBasePath() . $url->getPage() . '/')) {
            return true;
        }
        return false;
    }

    /**
     *    Tests to see if one string is a substring of
     *    another.
     *    @param string $part        Small bit.
     *    @param string $whole       Big bit.
     *    @return boolean            True if the small bit is
     *                               in the big bit.
     *    @access private
     */
    protected function isIn($part, $whole) {
        return strpos($whole, $part) === 0;
    }
}

/**
 *    Manages security realms.
 *    @package SimpleTest
 *    @subpackage WebTester
 */
class SimpleAuthenticator {
    private $realms;

    /**
     *    Clears the realms.
     *    @access public
     */
    function SimpleAuthenticator() {
        $this->restartSession();
    }

    /**
     *    Starts with no realms set up.
     *    @access public
     */
    function restartSession() {
        $this->realms = array();
    }

    /**
     *    Adds a new realm centered the current URL.
     *    Browsers privatey wildly on their behaviour in this
     *    regard. Mozilla ignores the realm and presents
     *    only when challenged, wasting bandwidth. IE
     *    just carries on presenting until a new challenge
     *    occours. SimpleTest tries to follow the spirit of
     *    the original standards committee and treats the
     *    base URL as the root of a file tree shaped realm.
     *    @param SimpleUrl $url    Base of realm.
     *    @param string $type      Authentication type for this
     *                             realm. Only Basic authentication
     *                             is currently supported.
     *    @param string $realm     Name of realm.
     *    @access public
     */
    function addRealm($url, $type, $realm) {
        $this->realms[$url->getHost()][$realm] = new SimpleRealm($type, $url);
    }

    /**
     *    Sets the current identity to be presented
     *    against that realm.
     *    @param string $host        Server hosting realm.
     *    @param string $realm       Name of realm.
     *    @param string $username    Username for realm.
     *    @param string $password    Password for realm.
     *    @access public
     */
    function setIdentityForRealm($host, $realm, $username, $password) {
        if (isset($this->realms[$host][$realm])) {
            $this->realms[$host][$realm]->setIdentity($username, $password);
        }
    }

    /**
     *    Finds the name of the realm by comparing URLs.
     *    @param SimpleUrl $url        URL to test.
     *    @return SimpleRealm          Name of realm.
     *    @access private
     */
    protected function findRealmFromUrl($url) {
        if (! isset($this->realms[$url->getHost()])) {
            return false;
        }
        foreach ($this->realms[$url->getHost()] as $name => $realm) {
            if ($realm->isWithin($url)) {
                return $realm;
            }
        }
        return false;
    }

    /**
     *    Presents the appropriate headers for this location.
     *    @param SimpleHttpRequest $request  Request to modify.
     *    @param SimpleUrl $url              Base of realm.
     *    @access public
     */
    function addHeaders(&$request, $url) {
        if ($url->getUsername() && $url->getPassword()) {
            $username = $url->getUsername();
            $password = $url->getPassword();
        } elseif ($realm = $this->findRealmFromUrl($url)) {
            $username = $realm->getUsername();
            $password = $realm->getPassword();
        } else {
            return;
        }
        $this->addBasicHeaders($request, $username, $password);
    }

    /**
     *    Presents the appropriate headers for this
     *    location for basic authentication.
     *    @param SimpleHttpRequest $request  Request to modify.
     *    @param string $username            Username for realm.
     *    @param string $password            Password for realm.
     *    @access public
     */
    static function addBasicHeaders(&$request, $username, $password) {
        if ($username && $password) {
            $request->addHeaderLine(
                'Authorization: Basic ' . base64_encode("$username:$password"));
        }
    }
}
?>