*RESOLVED* Login with md5 encryption

[JJohnsenDK]

Hey

Im trying to make a login system. I encrypt the password into MySql database with the md5() function, that works just great. But how do i turn the encryption around and unencrypt the password when the user needs to login?

At the moment i'm using this code. I might be totally off course, but here it is:

[code]if(isset($_POST['submit'])){
if( empty($_POST['uname']) && (empty($_POST['upass']))){
header( "Location:Messages.php?msg=1" );
exit();
}

$_POST['upass'] = md5($_POST['upass']);

//Connecter til MySql Databasen.
include('config.php');
$query="select * from user where uname='".$_POST['uname']."'  and pw='".$_POST['upass']."' ";
$result=mysql_query($query);

$num=mysql_num_rows($result);
if($num>0 ){

//Laver sessions om til variabler
$mytime=time();
$mytime=date("H:i:s A",$mytime);
$_SESSION['time'] = $mytime;
$_SESSION['status'] = 'logged';
$_SESSION['username'] = $n;
//Sender brugeren videre til welcome.php hvis bruger og pass er rigtig
header("location:welcome.php");
exit;
}else{
$_SESSION['status'] = 'not logged';
header( "Location:Messages.php?msg=2" );
exit();
}
}[/code]

Im using this line $_POST['upass'] = md5($_POST['upass']); to unencrypt the password, but it doesnt work so its propperly not right. Anyone who can figure out what i should use insted?

[Orio]

md5 cannot be decrypted. md5 is a [url=http://en.wikipedia.org/wiki/Cryptographic_hash_function]hashing[/url] function.
If you want to check if a login is correct, md5 the given password (the one used to log in) and compare the two hashes.

Orio.

[taith]

[code]
$_POST['upass'] = md5($_POST['upass']);
[/code]
that cant happen... put
[code]
$pass= md5($_POST['upass']);.
[/code]
then
[code]
$query="select * from user where uname='".$_POST['uname']."'  and pw='".$pass."' ";
[/code]

[JJohnsenDK]

Thanks alot... Fast and great help, nice  ;D ... How do i set as RESOLVED? if there are a system like that here, anyways.

[DaveLinger]

just add "SOLVED: " in the topic title

[taith]

no problem... i try ;-) for any specific questions... feel free to pm me :-)

[JJohnsenDK]

Thanks alot.. Im not allowed to write pm tho  :-\

[taith]

oops