Re: [courier-users] ldapaliasd + FDS + asterisks in mail address = 400 service temporarily unavailable.

[Yevheniy D. <zh...@uv...>]

On 12/16/2009 09:54 PM, Yevheniy Demchenko wrote:
> Recently i've noticed that one of our heavily used mail servers started
> to throw "400 service temporarily unavailable" messages to logs. Problem
> occurs when courier tries to check an email with asterisks in address
> (i.e. rcpt to:<a*****@some.domain.com>) against ldap alias database.
> Esmtpd accepts those messages (RFC allows asterisks in mail addresses)
> and passes this address to ldapaliasd, which subsequently passes it
> unmodified to LDAP server in search filter
> (mail=a*****@some.domain.com). LDAP interprets asterisks as special
> wildcard symbol. At this point there is a problem. Instead of finding an
> exact a***** record in database, ldap server would return something
> matching the wildcard.
> Some LDAP servers (i.e., redhat directory server) don't allow consequent
> asterisks in search filter, throw a "Bad search filter" error and set
> non-zero errorcode. ldapaliasd than stops working for a while and
> rejects even regular-addressed messages with a "400 service temporarily
> unavailable" error.
> It seems, that asterisks (and possibly other special symbols) in mail
> addresses should be escaped before passing them to ldap.
>    
Proposed patch attached. Tested briefly.
May need somewhat better memory handling.

-- 
Ing. Yevheniy Demchenko
Senior Linux Administrator
UVT s.r.o.