Re: [openpgp] Need to publish bis-05

[Benjamin Kaduk <[e-mail]>]

On Fri, Jul 27, 2018 at 08:37:02PM +0000, brian m. carlson wrote:
> On Fri, Jul 27, 2018 at 03:20:32PM -0500, Benjamin Kaduk wrote:
> > On Fri, Jul 27, 2018 at 08:00:33PM +0000, brian m. carlson wrote:
> > > 
> > > I agree that we should lower this.  I happen to think the overhead
> > > involved in 64 KiB chunks isn't that significant, but if that's a
> > > concern, we could raise it to 1 MiB.  I'd like to point out, though,
> > > that I suggested a smaller chunk size because that's what TLS has
> > > traditionally done: most TLS implementations don't allow the full 16 MiB
> > > chunk size for DoS reasons.
> > 
> > Can you expound on this more?  It does not match my understanding of the
> > TLS ecosystem.  (Also, isn't it 16K?)
> 
> Ah, I believe I was misremembering.  The chunk size for encryption is
> indeed 2^14 bytes; I think I was remembering the handshake messages,
> which are 2^24 bytes.  OpenSSL at least does limit the size of the
> handshake messages, although, as you pointed out, not encrypted
> messages.

Thanks for clarifying (and looking it up!).

> Regardless, my (mistaken) impression was the reason for the original
> decision.  I think we should pick values that are safe for all
> reasonable implementations, including smaller ones, and where possible,
> be willing to see what other protocol specifiers have done and learn
> from their wisdom and mistakes.

FWIW, I agree that we should have values safe for all reasonable
implementations.

-Ben