Re: [openpgp] Padding packets

[Stephen Farrell <[e-mail]>]

Hi Folks,

I created a gitlab issue for this one. [1] Let's see if
we've actually got rough consensus on it though...

If I were to suggest that we've converged onto merge
request 204 ([2], use zeros for padding, recommend not
compressing them) would I be wrong? Please correct me
if so before Tuesday 19th if you can.

If nobody has a problem with that we can ask the
editors to try merge [2].

Thanks,
Stephen.

[1] https://gitlab.com/openpgp-wg/rfc4880bis/-/issues/132
[2] https://gitlab.com/openpgp-wg/rfc4880bis/-/merge_requests/204



On 15/06/2022 12:29, Werner Koch wrote:
> Hi!
> 
> The idea of a padding packet is in general a good idea and has been
> discussed many times:
> 
>     5.14.  Padding Packet (Tag 21)
> 
>     The Padding packet contains random data, and can be used to defend
>     against traffic analysis (see Section 14.10) on version 2 SEIPD
>     [...]
>     Its contents SHOULD be random octets to make the length obfuscation
>     it provides more robust even when compressed.
> 
> The problem with random padding packets is that this opens a high
> capacity channel with all its problems.  Having this in the protocol is
> a problem because applications taking care not to leak too much
> information will need to reject such messages and inform the user about
> a possible problem.
> 
> Please drop this.  A better mechanism to add padding is by handling this
> at the MIME layer.  In any case, a well defined pseudo-random generator
> is required.
> 
> At this opportunity I checked the Literal Data packet and unfortunately
> noticed that not only the 'u' has gone but also the 'm' which we
> introduced to declare MIME content to avoid relying on heuristics.  That
> these flags are not included in the signed material is not a problem,
> because they are only hints to the implementation.
> 
> 
> Salam-Shalom,
> 
>     Werner
> 
> 
> 
> _______________________________________________
> openpgp mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/openpgp