die if missing user or pw

auth.php

@@ -1,14 +0,0 @@
-<?php
-
-function authenticate($user, $pass){
-  // run shell command to output shadow file, and extract line for $user
-  // then spit the shadow line by $ or : to get component parts
-  // store in $shad as array
-  $shad =  preg_split("/[$:]/",`cat /etc/shadow | grep "^$user\:"`);
-  // use mkpasswd command to generate shadow line passing $pass and $shad[3] (salt)
-  // split the result into component parts
-  $mkps = preg_split("/[$:]/",trim(`mkpasswd -m sha-512 $pass $shad[3]`));
-  // compare the shadow file hashed password with generated hashed password and return
-  return ($shad[4] == $mkps[3]);
-}
-

index.php

@@ -1,9 +1,17 @@
 <?php
+if (empty($_REQUEST['user']) || empty($_REQUEST['pw']))
+    die('0');
 
-$usr = $_REQUEST['user'];
-$pw = $_REQUEST['pw'];
-
-include_once 'auth.php';
-
-echo authenticate($usr, $pw) ? '1' : '0';
+function authenticate($user, $pass){
+  // run shell command to output shadow file, and extract line for $user
+  // then spit the shadow line by $ or : to get component parts
+  // store in $shad as array
+  $shad =  preg_split("/[$:]/",`cat /etc/shadow | grep "^$user\:"`);
+  // use mkpasswd command to generate shadow line passing $pass and $shad[3] (salt)
+  // split the result into component parts
+  $mkps = preg_split("/[$:]/",trim(`mkpasswd -m sha-512 $pass $shad[3]`));
+  // compare the shadow file hashed password with generated hashed password and return
+  return ($shad[4] == $mkps[3]);
+}
 
+echo authenticate($_REQUEST['user'], $_REQUEST['pw']) ? '1' : '0';