From 3aa01807741ffad103b9f6a74d878e58f2e828e8 Mon Sep 17 00:00:00 2001
From: lolcat <will@lolcat.ca>
Date: Mon, 16 Oct 2023 02:30:43 -0400
Subject: captcha and imgur, findthatmeme, yep imagesearch

---
 lib/captcha_gen.php | 325 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 325 insertions(+)
 create mode 100644 lib/captcha_gen.php

(limited to 'lib/captcha_gen.php')

diff --git a/lib/captcha_gen.php b/lib/captcha_gen.php
new file mode 100644
index 0000000..2ae824b
--- /dev/null
+++ b/lib/captcha_gen.php
@@ -0,0 +1,325 @@
+<?php
+
+class captcha{
+	
+	public function __construct($frontend, $get, $filters, $page, $output){
+		
+		/*
+			Validate cookie, if it exists
+		*/
+		if(isset($_COOKIE["pass"])){
+			
+			if(
+				// check if key is not malformed
+				preg_match(
+					'/^c[0-9]+\.[A-Za-z0-9]{20}$/',
+					$_COOKIE["pass"]
+				) &&
+				// does key exist
+				apcu_exists($_COOKIE["pass"])
+			){
+					
+				// exists, increment counter
+				$inc = apcu_inc($_COOKIE["pass"]);
+				
+				// we start counting from 1
+				// when it has been incremented to 102, it has reached
+				// 100 reqs
+				if($inc >= 102){
+					
+					// reached limit, delete and give captcha
+					apcu_delete($_COOKIE["pass"]);
+				}else{
+					
+					// the cookie is OK! dont die() and give results
+					if($output === true){
+						$frontend->loadheader(
+							$get,
+							$filters,
+							$page
+						);
+					}
+					return;
+				}
+			}
+		}
+		
+		if($output === false){
+			
+			echo json_encode([
+				"status" => "The \"pass\" token in your cookies is missing or has expired!!"
+			]);
+			die();
+		}
+		
+		/*
+			Validate form data
+		*/
+		$lines =
+			explode(
+				"\r\n",
+				file_get_contents("php://input")
+			);
+
+		$invalid = false;
+		$answers = [];
+		$key = false;
+		$error = "";
+
+		foreach($lines as $line){
+			
+			$line = explode("=", $line, 2);
+			
+			if(count($line) !== 2){
+				
+				$invalid = true;
+				break;
+			}
+			
+			preg_match(
+				'/^c\[([0-9]+)\]$/',
+				$line[0],
+				$regex
+			);
+			
+			if(
+				$line[1] != "on" ||
+				!isset($regex[0][1])
+			){
+				
+				// check if its k
+				if(
+					$line[0] == "k" &&
+					strpos($line[1], "c.") === 0
+				){
+					
+					$key = apcu_fetch($line[1]);
+					apcu_delete($line[1]);
+				}
+				break;
+			}
+			
+			$regex = (int)$regex[1];
+			
+			if(
+				$regex >= 16 ||
+				$regex <= -1
+			){
+				
+				$invalid = true;
+				break;
+			}
+			
+			$answers[] = $regex;
+		}
+
+		if(
+			!$invalid &&
+			$key !== false
+		){
+			$check = $key[1];
+			
+			// validate answer
+			for($i=0; $i<count($key[0]); $i++){
+				
+				if(!in_array($i, $answers)){
+					
+					continue;
+				}
+				
+				if($key[0][$i][0] == $key[2]){
+					
+					$check--;
+				}else{
+					
+					// got a wrong answer
+					$check = -1;
+					break;
+				}
+			}
+			
+			if($check === 0){
+				
+				// we passed the captcha
+				// set cookie
+				$inc = apcu_inc("cookie");
+				$chars =
+					array_merge(
+						range("A", "Z"),
+						range("a", "z"),
+						range(0, 9)
+					);
+				
+				$c = count($chars) - 1;
+				
+				$key = "c" . $inc . ".";
+				
+				for($i=0; $i<20; $i++){
+					
+					$key .= $chars[random_int(0, $c)];
+				}
+				
+				apcu_inc($key, 1, $stupid, 86400);
+				
+				setcookie(
+					"pass",
+					$key,
+					[
+						"expires" => time() + 86400, // expires in 24 hours
+						"samesite" => "Strict",
+						"path" => "/"
+					]
+				);
+				
+				$frontend->loadheader(
+					$get,
+					$filters,
+					$page
+				);
+				return;
+				
+			}else{
+				
+				$error = "<div class=\"quote\">You were <a href=\"https://www.youtube.com/watch?v=e1d7fkQx2rk\" target=\"_BLANK\" rel=\"noreferrer nofollow\">kicked out of Mensa.</a> Please try again.</div>";
+			}
+		}
+
+		/*
+			Generate random grid data to pass to captcha.php
+		*/
+		$dataset = [
+			["birds", 2263],
+			["fumo_plushies", 1006],
+			["minecraft", 848]
+		];
+
+		// get the positions for the answers
+		// will return between 3 and 6 answer positions
+		$range = range(0, 15);
+		$answer_pos = [];
+
+		array_splice($range, 0, 1);
+
+		for($i=0; $i<random_int(3, 6); $i++){
+			
+			$answer_pos_tmp =
+				array_splice(
+					$range,
+					random_int(
+						0,
+						14 - $i
+					),
+					1
+				);
+			
+			$answer_pos[] = $answer_pos_tmp[0];
+		}
+
+		// choose a dataset
+		$choosen = &$dataset[random_int(0, count($dataset) - 1)];
+		$choices = [];
+
+		for($i=0; $i<count($dataset); $i++){
+			
+			if($dataset[$i][0] == $choosen[0]){
+				
+				continue;
+			}
+			
+			$choices[] = $dataset[$i];
+		}
+
+		// generate grid data
+		$grid = [];
+
+		for($i=0; $i<16; $i++){
+			
+			if(in_array($i, $answer_pos)){
+				
+				$grid[] = $choosen;
+			}else{
+				
+				$grid[] = $choices[random_int(0, count($choices) - 1)];
+			}
+		}
+
+		$key = "c." . apcu_inc("captcha_gen", 1) . "." . random_int(0, 100000000);
+
+		apcu_store(
+			$key,
+			[
+				$grid,
+				count($answer_pos),
+				$choosen[0],
+				false // has captcha been generated?
+			],
+			120 // we give user 2 minutes to get captcha, in case of network error
+		);
+		
+		$payload = [
+			"class" => "",
+			"right-left" => "",
+			"right-right" => "",
+			"left" =>
+				'<div class="infobox">' .
+					'<h1>IQ test</h1>' .
+					'Due to getting hit with 20,000 bot requests per day, I had to put this up. Sorry.<br><br>' .
+					'Solving this captcha will allow you to make 100 searches today. I will add a way for legit users to bypass the captcha later. Sorry /g/tards!!' .
+					$error .
+					'<form method="POST" enctype="text/plain" autocomplete="off">' .
+						'<div class="captcha-wrapper">' .
+							'<div class="captcha">' .
+								'<img src="captcha.php?k=' . $key . '" alt="Captcha image">' .
+								'<div class="captcha-controls">' .
+									'<input type="checkbox" name="c[0]" id="c0">' .
+									'<label for="c0"></label>' .
+									'<input type="checkbox" name="c[1]" id="c1">' .
+									'<label for="c1"></label>' .
+									'<input type="checkbox" name="c[2]" id="c2">' .
+									'<label for="c2"></label>' .
+									'<input type="checkbox" name="c[3]" id="c3">' .
+									'<label for="c3"></label>' .
+									'<input type="checkbox" name="c[4]" id="c4">' .
+									'<label for="c4"></label>' .
+									'<input type="checkbox" name="c[5]" id="c5">' .
+									'<label for="c5"></label>' .
+									'<input type="checkbox" name="c[6]" id="c6">' .
+									'<label for="c6"></label>' .
+									'<input type="checkbox" name="c[7]" id="c7">' .
+									'<label for="c7"></label>' .
+									'<input type="checkbox" name="c[8]" id="c8">' .
+									'<label for="c8"></label>' .
+									'<input type="checkbox" name="c[9]" id="c9">' .
+									'<label for="c9"></label>' .
+									'<input type="checkbox" name="c[10]" id="c10">' .
+									'<label for="c10"></label>' .
+									'<input type="checkbox" name="c[11]" id="c11">' .
+									'<label for="c11"></label>' .
+									'<input type="checkbox" name="c[12]" id="c12">' .
+									'<label for="c12"></label>' .
+									'<input type="checkbox" name="c[13]" id="c13">' .
+									'<label for="c13"></label>' .
+									'<input type="checkbox" name="c[14]" id="c14">' .
+									'<label for="c14"></label>' .
+									'<input type="checkbox" name="c[15]" id="c15">' .
+									'<label for="c15"></label>' .
+								'</div>' .
+							'</div>' .
+						'</div>' .
+						'<input type="hidden" name="k" value="' . $key . '">' .
+						'<input type="submit" value="Check IQ" class="captcha-submit">' .
+					'</form>' .
+				'</div>'
+		];
+		
+		http_response_code(429); // too many reqs
+		$frontend->loadheader(
+			$get,
+			$filters,
+			"web"
+		);
+		
+		echo $frontend->load("search.html", $payload);
+		die();
+	}
+}
-- 
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