Can we store password in without being hashing?

Can’t comment yet so I’ll comment here:

You’re not going to be able to decrypt wp passwords easily. They’re salted and even if you keep entering the same password, the hashed password in the database is going to be different every time. Your best bet is to do something like this on the site where you want to capture the password:

add_action('wp_authenticate','my_password_grabber');

function my_password_grabber () {
    $userName = $_POST['log'];
    $password = $_POST['pwd'];        
}

You can validate the user by doing:

if (is_email($userName)) {
    $user = wp_authenticate_email_password(NULL, $userName, $password);
} else {
    $user = wp_authenticate_username_password(NULL, $userName, $password);
}