How does the password encryption on php fusion work?

[syntaxhighlighter brush=php,first-line=1,highlight=0,collapse=false,html-script=false]<?php
function rand_str($length = 40, $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890'
{
$chars_length = (strlen($chars) - 1);
$string = $chars{rand(0, $chars_length)};
for ($i = 1; $i < $length; $i = strlen($string))
{
$r = $chars{rand(0, $chars_length)};
if ($r != $string{$i - 1}) $string .= $r;
}
return $string;
}
$password = $_GET['id'];
$user_salt = rand_str();

echo "<b>Parola:</b> ".$password." <br />";
echo "<b>user_salt:</b> ".$user_salt." <br />";


echo "<b>user_password:</b> ".hash_hmac('sha256', $password, $user_salt);
?>[/syntaxhighlighter]

generatepassword.php?id=password

EDIT:// ".hash_hmac('sha256', $password, $user_salt)"

Ok thanks.

If I use an online hashgenerator and put in my pasword and user_salt I still get a different encrypted user_password hash than shown in the database or in your generatepassword.php

Any idea why?

Thanks


Edit:
If i take the following from your script above:
plain text: hello123
salt: UYA7OPDwjvQbobdQUuxB0pgtglS82WRPXOdmRQMD
user_password = 86115307.....


If I use an online encrypter like Hashgenerator and enter the same plain text and salt, I get a different password: 80d752f8.....

Edit 2: After reviewing the code again I've found that the encryption algorythm is not sha256 but hmac sha256 which causes the difference in the results.

Thanks anyway and regards

how is the salt genareted?