fix wikipedia crashgrafted

1 files changed, 100 insertions, 0 deletions

diff --git a/lib/anubis.php b/lib/anubis.php
new file mode 100644
index 0000000..2bd6d90
--- /dev/null
+++ b/lib/anubis.php
@@ -0,0 +1,100 @@
+<?php
+
+//
+// Reference
+// https://github.com/TecharoHQ/anubis/blob/ecc716940e34ebe7249974f2789a99a2c7115e4e/web/js/proof-of-work.mjs
+//
+
+class anubis{
+	
+	public function __construct(){
+		
+		include_once "fuckhtml.php";
+		$this->fuckhtml = new fuckhtml();
+	}
+	
+	public function scrape($html){
+		
+		$this->fuckhtml->load($html);
+		
+		$script =
+			$this->fuckhtml
+			->getElementById(
+				"anubis_challenge",
+				"script"
+			);
+		
+		if($script === false){
+			
+			throw new Exception("Failed to scrape anubis challenge data");
+		}
+		
+		$script =
+			json_decode(
+				$this->fuckhtml
+				->getTextContent(
+					$script
+				),
+				true
+			);
+		
+		if($script === null){
+			
+			throw new Exception("Failed to decode anubis challenge data");
+		}
+		
+		if(
+			!isset($script["challenge"]) ||
+			!isset($script["rules"]["difficulty"]) ||
+			!is_int($script["rules"]["difficulty"]) ||
+			!is_string($script["challenge"])
+		){
+			
+			throw new Exception("Found invalid challenge data");
+		}
+		
+		return $this->rape($script["challenge"], $script["rules"]["difficulty"]);
+	}
+	
+	private function is_valid_hash($hash, $difficulty){
+		
+		for ($i=0; $i<$difficulty; $i++) {
+			
+			$index = (int)floor($i / 2);
+			$nibble = $i % 2;
+			
+			$byte = ord($hash[$index]);
+			$nibble = ($byte >> ($nibble === 0 ? 4 : 0)) & 0x0f;
+			
+			if($nibble !== 0){
+				return false;
+			}
+		}
+		
+		return true;
+	}
+	
+	public function rape($data, $difficulty = 5){
+		
+		$nonce = 0;
+		
+		while(true){
+			
+			$hash_binary = hash("sha256", $data . $nonce, true);
+			
+			if($this->is_valid_hash($hash_binary, $difficulty)){
+				
+				$hash_hex = bin2hex($hash_binary);
+				
+				return [
+					"response" => $hash_hex,
+					//"data" => $data,
+					//"difficulty" => $difficulty,
+					"nonce" => $nonce
+				];
+			}
+			
+			$nonce++;
+		}
+	}
+}