Partial length headers

[David Shaw]

On Fri, Nov 21, 2003 at 08:16:20PM -0500, Hasnain Mujtaba wrote:
> 
> Thanks. A couple more questions:
> 
> Looking at the pgpdump of an encrypted file, I see that GPG uses the
> Symmetrically Encrypted and MDC Packet (tag 18). 
> 
> I cannot find this tag in RFC 2440. Where can I get more information on
> this tag type and its internal structure? I am trying to understand how
> partial length chunks are built. Are these partial chunks nested within
> the outer Symm Encrypted and MDC Packet? What is the name of the
> outer-most packet? Is it the Symmetrically Encrypted packet? 

The MDC packet is defined in 2440bis - the draft that will eventually
replace RFC-2440.  You can get the latest draft at
http://www.ietf.org/internet-drafts/draft-ietf-openpgp-rfc2440bis-09.txt

David