No, Windows does not support PAM, so there will not be a Windows version.
Yes, you need to add the mysql user to the shadow group. Because PAM libraries, such as ‘pam_unix.so’, need to access /etc/shadow.
For example this is how you can do it in Ubuntu:
root@lucid64:/var/lib/mysql# getent group shadow shadow:x:42:mysql root@lucid64:/var/lib/mysql# ls -alhs /etc/shadow 4.0K -rw-r----- 1 root shadow 912 Dec 21 10:39 /etc/shadow
After you restart mysqld for changes to take effect, pam_unix authentication will work.
The other option is to run mysqld as root. This should be used for testing only or as a last resort method.
This means that the default client plugin-dir setting doesn’t work or it isn’t set up properly. You’ll need to add the location of the plugin folder to your client configuration: