I recently found myself in the awkward situation of having only a Super Admin user in the Joomla installation, and neither I nor my client knew the password. I had to the fix the problem, and I decided to do so by generating a Joomla user password (which required a lot of searching through code, mind you). Here's the PHP code I used:
<?php // JUserHelper class from libraries/joomla/user/helper.php $pwd = 'my_new_password'; $instance = new JUserHelper(); $salt = $instance->genRandomPassword(32); $final_pwd = $instance->getCryptedPassword($pwd, $salt) . ':' . $salt; ?>
(Note that I have to use the <?php tags to get syntax highlighting to work properly.)
This is the technique Joomla uses to generate a password when a password reset is requested. The JUserHelper class provides the hashing functions we need. A Joomla password is made up of two sections separated by a colon; the first is the hashed password, and the second is the salt used to hash it.
However, for a simple technique, that will work just fine, you can use the md5 function:
<?php $pwd = md5('my_new_password'); ?>
Or even an SQL query:
UPDATE jos_users SET password = MD5('password') WHERE id = <user_id_here>;
But that's not the standard Joomla way of doing it. If you used the PHP code, you can update the user with this query:
UPDATE jos_users SET password = <password_here> WHERE id = <user_id_here>;
Hope that helps.