init commit

data/idObfuscation.php

@@ -0,0 +1,43 @@
+<?php
+function getObfuscationSalt(){
+	$saltFile=dirname(__FILE__)."/idObfuscation_salt.php";
+	if(file_exists($saltFile)){
+		require $saltFile;
+	}else{
+		$bytes=openssl_random_pseudo_bytes(4);
+		$sf=fopen($saltFile,"w");
+		fwrite($sf,chr(60)."?php\n");
+		fwrite($sf,'$OBFUSCATION_SALT=0x'.bin2hex($bytes).";\n");
+		fwrite($sf,"?".chr(62));
+		fclose($sf);
+		require $saltFile;
+	}
+	return isset($OBFUSCATION_SALT)?$OBFUSCATION_SALT:0;
+}
+/*
+This is a simple reversible hash function I made for encoding and decoding test IDs.
+It is not cryptographically secure, don't use it to hash passwords or something!
+*/
+function obfdeobf($id,$dec){
+	$salt=getObfuscationSalt()&0xFFFFFFFF;
+	$id=$id&0xFFFFFFFF;
+	if($dec){
+		$id=$id^$salt;
+		$id=(($id&0xAAAAAAAA)>>1)|($id&0x55555555)<<1;
+		$id=(($id&0x0000FFFF)<<16)|(($id&0xFFFF0000)>>16);
+		return $id;
+	}else{
+		$id=(($id&0x0000FFFF)<<16)|(($id&0xFFFF0000)>>16);
+		$id=(($id&0xAAAAAAAA)>>1)|($id&0x55555555)<<1;
+		return $id^$salt;
+	}
+}
+function obfuscateId($id){
+	return str_pad(base_convert(obfdeobf($id+1,false),10,36),7,0,STR_PAD_LEFT);
+}
+function deobfuscateId($id){
+	return obfdeobf(base_convert($id,36,10),true)-1;
+}
+
+//IMPORTANT: DO NOT ADD ANYTHING BELOW THE PHP CLOSING TAG, NOT EVEN EMPTY LINES!
+?>