Re: [TLS] Strawman on EdDSA/Ed25519 in TLS

Ilari Liusvaara <ilari.liusvaara@elisanet.fi> Wed, 20 May 2015 20:30 UTC

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Date: Wed, 20 May 2015 23:30:11 +0300
From: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
To: Simon Josefsson <simon@josefsson.org>
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Subject: Re: [TLS] Strawman on EdDSA/Ed25519 in TLS
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On Wed, May 20, 2015 at 07:14:47PM +0200, Simon Josefsson wrote:
>
> Support for EdDSA/Ed25519 in TLS has been suggested a couple of times.
> I have started to work on an I-D to describe more precisely what that
> would actually mean, and here is an initial strawman document:
> 
> https://tools.ietf.org/html/draft-josefsson-tls-eddsa-00
> 
> I'm confident I missed some major pieces of the puzzle, but feedback and
> review is welcome so the document can be improved into something that
> can be implemented and interoperate.

More ciphersuites? The signature algorithm negotiation (extension 13)
doesn't work in practice?

> One aspect I'm aware of is that there is no OID allocated nor
> specification of PKIX certificates with EdDSA/Ed25519 public keys.  I'm
> not sure the above document is the right place for doing that though,
> and more thinking around this topic is especially appreciated.

AFAIK, a way to put the key into PKIX SPKI is required for the
new signature algorithm to be useful.

And that means OIDs. The curve itself is 1.3.6.1.4.1.11591.15.1,
but AFAIK, there is no OID for the signature primitive.

I think one can find more expertise about how to put various
keys into SPKI in the PKIX mailinglist.


Reading the PKIX specs, it seems like there are two ways:

1) Use algorithm "Unresricted" and use a new point format to
denote LE edwards points.

2) Define new algorithm (OID) for EdDSA, put the curve OID
as parameter and the LE edwards point as the key.



-Ilari