[Mimedefang] Not piggybacking HELO checks

[Jan Pieter Cornet]

On Tue, Jan 10, 2006 at 07:11:35PM -0700, Philip Prindeville wrote:
> >This seems like pretty weak security to me.  Is there a valid reason for
> >having sites answer to an EXPN or VRFY?
> 
> Agreed that it's weak security: some legacy management software requires it.
> 
> But... that doesn't change the fact that having individual knobs and 
> controls
> provides finer tuning...  And it might be nice to block the connection 
> before
> we've exposed too much information.

Can't you use an IP-based access control? That can be done in stock
sendmail via the access.db

If that's not possible, due to roaming or dynamic users, I'd switch
to SSL, and SMTP AUTH.

> Well, from a purely architectural point of view... a symmetrical
> design would provide a control hook at each transition point in the
> state machine...

Last I heard, there was a bug in sendmail that makes it ignore the
error code from a milter after the xxfi_helo call... but that might
be fixed nowadays.

-- 
#!perl -wpl # mmfppfmpmmpp mmpffm <pmmppfmfpppppfmmmf at fpffmm4mmmpmfpmf.ppppmf>
$p=3-2*/[^\W\dmpf_]/i;s.[a-z]{$p}.vec($f=join('',$p-1?chr(sub{$_[0]*9+$_[1]*3+
$_[2]}->(map{/p|f/i+/f/i}split//,$&)+97):qw(m p f)[map{((ord$&)%32-1)/$_%3}(9,
3,1)]),5,1)='`'lt$&;$f.eig;                                # Jan-Pieter Cornet