poster IDs

inc/config.php

@@ -62,7 +62,7 @@
 	$config['cookies']['salt']	= 'wefaw98YHEWUFuo';
 	// How long should moderators should remain logged in (0=browser session) (in seconds)
 	$config['mod']['expire']	= 15778463; //6 months
-	// Used to salt secure tripcodes (##trip)
+	// Used to salt secure tripcodes (##trip) and poster IDs (if enabled)
 	$config['secure_trip_salt']	= '@#$&^@#)$(*&@!_$(&329-8347';
 	
 	// How many seconds before you can post, after the first visit
@@ -533,6 +533,12 @@
 	// Always act as if they had typed "noko" in the email field no mattter what
 	$config['always_noko']	= false;
 	
+	// Assign each poster in a thread a unique ID, shown by "ID: {id}" before the post number.
+	$config['poster_ids'] = false;
+	
+	// Number of characters in the poster ID (maximum is 40)
+	$config['poster_id_length'] = 5;
+	
 	// Characters used to generate a random password (with Javascript)
 	$config['genpassword_chars'] = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()_+';
 	

inc/display.php

@@ -240,9 +240,14 @@
 			$built .= ' ' . date($config['post_date'], $this->time);
 			
 			// End delete
-			$built .= '</label>';
+			$built .= '</label>'
 			
-			$built .= ' <a class="post_no"' . 
+			// Poster ID
+			. ($config['poster_ids'] ?
+				' ID: ' . poster_id($this->ip, $this->thread)
+			: '')
+			
+			. ' <a class="post_no"' . 
 			// JavaScript highlight
 				($index?'':' onclick="highlightReply(' . $this->id . ');"') .
 				' href="' . $this->root . $board['dir'] . $config['dir']['res'] . $this->thread . '.html' . '#' . $this->id . '">No.</a>' . 
@@ -416,9 +421,14 @@
 			$built .= ' ' . date($config['post_date'], $this->time);
 			
 			// End delete
-			$built .= '</label>';
+			$built .= '</label>'
+			
+			// Poster ID
+			. ($config['poster_ids'] ?
+				' ID: ' . poster_id($this->ip, $this->id)
+			: '')
 			
-			$built .= ' <a class="post_no"' . 
+			. ' <a class="post_no"' . 
 			// JavaScript highlight
 			($index?'':' onclick="highlightReply(' . $this->id . ');"') .
 			' href="' . $this->root . $board['dir'] . $config['dir']['res'] . $this->id . '.html' . '#' . $this->id . '">No.</a>' . 

inc/functions.php

@@ -1159,9 +1159,16 @@
 			reset($objects);
 			rmdir($dir);
 		}
-	} 
+	}
+	
+	function poster_id($ip, $thread) {
+		global $config;
+		
+		// Confusing, hard to brute-force, but simple algorithm
+		return substr(sha1(sha1($ip . $config['secure_trip_salt'] . $thread) . $config['secure_trip_salt']), 0, $config['poster_id_length']);
+	}
  
-	function generate_tripcode ( $name, $length = 10 ) {
+	function generate_tripcode($name, $length = 10){
 		global $config;
 		$name = stripslashes ( $name );
 		$t = explode('#', $name);