<?php
/*
 * Authentication checks : login base64 encoded, password hash with custom function
 * ------------------------------------------------------------------------------------------
 */
 
if( isset($_POST["pwd"]) ) {
  mysql_connect("db_host","db_user","db_password");
 
  if( $_GET["page"] == "inscription" ) {
    $res = mysql_query("INSERT INTO `db_users`.`tbl_auth` (`usr`, `pwd`) VALUES ('".base64_encode($_POST["usr"])."', '"
                       .custom_hash($_POST["pwd"])."');");
 
    if( $res ) {
      echo "Register successful.";
    }
  }
 
  if( $_GET["page"] == "connexion" ) {
    $sql = "SELECT * FROM `db_users`.`tbl_auth` WHERE usr LIKE '".base64_encode($_POST["usr"])."' AND pwd LIKE '"
            .custom_hash($_POST["pwd"])."'";
 
    $res = mysql_query($sql);
    if( $res ) {
      $obj = mysql_fetch_object($res);
 
      if( $obj ) {
        echo "Connected as user: ".base64_decode($obj->usr);
      }
    }
  }
}  ?>
 
 

 
<?php
/*
 * Sha1 hash with salt, base64 encode and compression ...
 * and a custom replacement
 * ------------------------------------------------------------------------------------------
 */
 
function custom_hash($str,$salt1="y.fph_xAuJuvB%S,=UZFeM=8B0xg1QG")
{
  $match = array( 0=> "a", "b", "c", "d", "e", "f" );
  $replace = array( 0=> "4", "8", "2", "9", "5", "0" );
  $res = base64_encode( gzdeflate($salt1.$str) );
  return(  str_replace( $match,$replace,sha1($res) )  );
}
?>