- strpos: documentation ( source)
- md5: documentation ( source)
<?php
$username = "test";
$password = "";
$authString = $username . " " . md5($password);
$file = "test d41d8cd98f00b204e9800998ecf8427e";
echo $authString;
if (strpos($file, $authString) !== FALSE ){
echo "LOGIN SUCCESS";
} else {
echo 'INCORRECT CREDENTIALS. TRY AGAIN';
}