Re: [openpgp] Deprecating compression support

"Neal H. Walfield" <neal@walfield.org> Mon, 18 March 2019 13:22 UTC

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Date: Mon, 18 Mar 2019 14:22:25 +0100
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From: "Neal H. Walfield" <neal@walfield.org>
To: Justus Winter <justuswinter@gmail.com>
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Subject: Re: [openpgp] Deprecating compression support
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Hi Justus,

Thanks for bringing this up.

On Mon, 18 Mar 2019 13:07:21 +0100,
Justus Winter wrote:
> I propose to deprecate compression support in OpenPGP.
> ...
> I realize that we cannot suddenly drop decompression support, but I
> would suggest to stop emitting compressed data packets.  If this
> proposal gathers traction, I would be happy to suggest a change to the
> standard.

I propose that we change the standard to say:

  - Compliant implementations MUST NOT emit compressed data packets.

  - For backwards compatibility, compliant implementations MAY
    decompress compressed data packets.

Obviously, we should deprecate the "Preferred Compression Algorithms"
subpacket as well.

Note: removing compression support was one of the original goals:

  Subject: [openpgp] details of 4880bis work
  From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
  Message-ID: <5527B621.3040104@cs.tcd.ie>
  Date: Fri, 10 Apr 2015 12:38:09 +0100
  Archived-At: <http://mailarchive.ietf.org/arch/msg/openpgp/ll36RGS81vXSXkVey0cR0zZ7WkI>

  ...

  g) remove compression entirely

  ...

:) Neal