Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 17 Mar 2010 14:00:43 +0000
From: Brian Stafford <>
To: Ludwig Nussel <>
Cc:,,, Pawel Salek <>,
Subject: Re: CVE Request: libesmtp does not check NULL bytes
 in commonName

Ludwig Nussel wrote:
> Brian Stafford wrote:
>> Since both the original and patched versions of match_component() 
>> implement wildcards rather less liberally than RFC 2818 implies, I 
>> decided to move towards the approach in the I-D.  match_component() now 
>> accepts either a string or a single wildcard '*'.  Matched characters 
>> are validated against the set of valid domain name component characters 
>> , that is, * will not match, nor for that 
>> matter will the pattern  Question: should underline '_' 
>> be in the set of valid characters?
> AFAIK underlines are not allowed in DNS. I'm sure someone knows the
> RFC for that too :-)
They are permitted in some contexts but not in actual domain names, for 
example a SRV record question to a name server contains stuff like  The section is forbidden 
from using _ but obviously the name server itself supports it so it can 
handle the _smtp._tcp components.  I am assuming that since we're 
validating domain names and not name server queries, the _ is forbidden 
but if anyone out there can clarify it might be useful :-)
> cu
> Ludwig

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.