How do I find users by password?

Question

I need to add a passkey to each user, so I decided to just giving the user password that value and use WP functionality to store it/retrieve it.

So now I need to find what user that password belongs to, so a single field would be necessary to identify him, rather than asking for email AND passkey.

How do I find a user by password? I know what is stored in the DB are not passwords, but something else, but I don't care. We won't have enough users for getting two with the same MD5 (or whatever is stored)

Thanks.

Answer 1

The user password (stored as an MD5 hash) can be retrieved like so:

$users = get_users();

foreach ( $users as $user ) {
    $password = $user->user_pass;
}

Assuming you have some known value for passkey, you can hash it and compare it to each user's password:

$passkey = 'somestring';

$hashed_passkey = md5( $passkey );

$users = get_users();

foreach ( $users as $user ) {
    if ( $user->user_pass == $hashed_passkey ) {
        // We have a match!
        // Do something
    }
}