[Exim] Basic Auth question

I have a question about the smtp authentication. I added the
following to my 3.x /usr/exim/configure file:


plain:
driver=plaintext
public_name=PLAIN
server_condition="${if pam{$2:$3}{1}{0}}"
server_set_id=$2

login:
driver=plaintext
public_name=LOGIN
server_condition="${if pam{$1:$2}{1}{0}}"
server_prompts="Username:: : Password::"
server_set_id=$1



This makes authentication work nicely, although figuring out how
to do this was difficult. Is this configured the same in 4.x,
or is it easier? I'm trying to prepare for a version upgrade.

Thanks,
Mark Lehrer