<?php
/**
* copyright            : (C) 2001-2018 Advanced Internet Designs Inc.
* email                : forum@prohost.org
* $Id$
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; version 2 of the License.
**/

/* Generate a CAPTCHA question to display. */
function generate_turing_val()
{
	if (defined('plugins')) {
		$text = plugin_call_hook('CAPTCHA');
                if (!empty($text)) {
                        return $text;
                }
	}

	$t = array(
		array('..#####..','..#####..','.#.......','.#######.','..#####..','.#######.','..#####..','..#####..','....###....','.########..','..######..','.########.','.########.','..######...','.##.....##.','.####.','.......##.','.##....##.','.##.......','.##.....##.','.##....##.','.########..','..#######..','.########..','..######..','.########.','.##.....##.','.##.....##.','.##......##.','.##.....##.','.##....##.','.########.'),
		array('.#.....#.','.#.....#.','.#....#..','.#.......','.#.....#.','.#....#..','.#.....#.','.#.....#.','...##.##...','.##.....##.','.##....##.','.##.......','.##.......','.##....##..','.##.....##.','..##..','.......##.','.##...##..','.##.......','.###...###.','.###...##.','.##.....##.','.##.....##.','.##.....##.','.##....##.','....##....','.##.....##.','.##.....##.','.##..##..##.','..##...##..','..##..##..','......##..'),
		array('.......#.','.......#.','.#....#..','.#.......','.#.......','.....#...','.#.....#.','.#.....#.','..##...##..','.##.....##.','.##.......','.##.......','.##.......','.##........','.##.....##.','..##..','.......##.','.##..##...','.##.......','.####.####.','.####..##.','.##.....##.','.##.....##.','.##.....##.','.##.......','....##....','.##.....##.','.##.....##.','.##..##..##.','...##.##...','...####...','.....##...'),
		array('..#####..','....###..','.#....#..','.######..','.######..','....#....','..#####..','..######.','.##.....##.','.########..','.##.......','.######...','.######...','.##...####.','.#########.','..##..','.......##.','.#####....','.##.......','.##.###.##.','.##.##.##.','.########..','.##.....##.','.########..','..######..','....##....','.##.....##.','.##.....##.','.##..##..##.','....###....','....##....','....##....'),
		array('.#.......','.......#.','.#######.','.......#.','.#.....#.','...#.....','.#.....#.','.......#.','.#########.','.##.....##.','.##.......','.##.......','.##.......','.##....##..','.##.....##.','..##..','.##....##.','.##..##...','.##.......','.##.....##.','.##..####.','.##........','.##..##.##.','.##...##...','.......##.','....##....','.##.....##.','..##...##..','.##..##..##.','...##.##...','....##....','...##.....'),
		array('.#.......','.#.....#.','......#..','.#.....#.','.#.....#.','...#.....','.#.....#.','.#.....#.','.##.....##.','.##.....##.','.##....##.','.##.......','.##.......','.##....##..','.##.....##.','..##..','.##....##.','.##...##..','.##.......','.##.....##.','.##...###.','.##........','.##....##..','.##....##..','.##....##.','....##....','.##.....##.','...##.##...','.##..##..##.','..##...##..','....##....','..##......'),
		array('.#######.','..#####..','......#..','..#####..','..#####..','...#.....','..#####..','..#####..','.##.....##.','.########..','..######..','.########.','.##.......','..######...','.##.....##.','.####.','..######..','.##....##.','.########.','.##.....##.','.##....##.','.##........','..#####.##.','.##.....##.','..######..','....##....','..#######..','....###....','..###..###..','.##.....##.','....##....','.########.'),
		array('2','3','4','5','6','7','8','9','A','B','C','E','F','G','H','I','J','K','L','M','N','P','Q','R','S','T','U','V','W','X','Y','Z')
	);

	$rv      = array_rand($t[0], 4);
	$captcha = $t[7][$rv[0]] . $t[7][$rv[1]] . $t[7][$rv[2]] . $t[7][$rv[3]];
	$rt      = md5($captcha);

	$text = '<input type="text" name="turing_test" id="turing_test" size="25" required="required" placeholder="There is no zero or one in the image." />';
	$text .= '<input type="hidden" name="turing_res" value="'. $rt .'" />';

	if (($GLOBALS['FUD_OPT_3'] & 33554432) && extension_loaded('gd') && function_exists('imagecreate') ) {
		// Graphical captcha.
		ses_putvar((int)$GLOBALS['usr']->sid, $captcha);
		return $text .'<br />
<img src="[[relativeurl]]/index.php/index.php?t=captchaimg" alt="Captcha Verification: you will need to recognize the text in this image." />';
	} else {
		// Text based captcha.
		$bg_fill_chars = array(' ', '.', ',', '`', '_', '\'');
		$bg_fill       = $bg_fill_chars[array_rand($bg_fill_chars)];
		$fg_fill_chars = array('&#35;', '&#64;', '&#36;', '&#42;', '&#88;');
		$fg_fill       = $fg_fill_chars[array_rand($fg_fill_chars)];

		$text .= '<pre>';
		// Generate turing text.
		for ($i = 0; $i < 7; $i++) {
			foreach ($rv as $v) {
				$text .= str_replace('#', $fg_fill, str_replace('.', $bg_fill, $t[$i][$v]));
			}
			$text .= '<br />';
		}
	 	return $text .'</pre>';
	}
}

/* Test if user entered a valid response to the CAPTCHA test. */
// function test_turing_answer($test, $res)
function test_turing_answer()
{
	if (defined('plugins')) {
		$ok = plugin_call_hook('CAPTCHA_VALIDATE');
	 	if ($ok == 0) {
			return false;
		} elseif ($ok == 1) {
			return true;
		}
	}

	$test = $_POST['turing_test'];
	$res  = $_POST['turing_res'];
	if (empty($test) || empty($res)) {
		return false;
	}

	if (md5(strtoupper(trim($test))) != $res) {
		return false;
	} else {
		return true;
	}
}

?>