Re: [openpgp] AEAD Chunk Size

"Neal H. Walfield" <neal@walfield.org> Fri, 01 March 2019 09:02 UTC

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Date: Fri, 01 Mar 2019 10:01:47 +0100
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From: "Neal H. Walfield" <neal@walfield.org>
To: Bart Butler <bartbutler@protonmail.com>
Cc: "openpgp@ietf.org" <openpgp@ietf.org>, Vincent Breitmoser <look@my.amazin.horse>
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Subject: Re: [openpgp] AEAD Chunk Size
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At Thu, 28 Feb 2019 19:44:41 +0000,
Bart Butler wrote:
> I can't because I do not know--it's an experimental feature in OpenPGP.js. I do know that some users of the library are using it internally in closed systems, and we'd prefer not to break decryption for their existing messages but also prefer not to keep supporting an obsolete draft. You could argue that they shouldn't have used an experimental feature for production but given how overdue AEAD is for PGP I find it difficult to blame them myself.
> 
> ProtonMail doesn't use V5 keys yet at all, as we exist within the federated email ecosystem and it would break compatibility. So this is not coming from us personally, just on behalf of the OpenPGP.js community in general.

For continuity, in:

  Message-ID: <87o96vezt7.wl-neal@walfield.org>
  https://mailarchive.ietf.org/arch/msg/openpgp/JukTMAMY-RUoHsHxVxyZNht96R4

I proposed changing the chunk size to a magic value whose value is the
current C value for 256 kiB chunks, and to fix the chunk size to 256
kiB.