Re: [pkix] PKCS #8? Re: Updated EdDSA/Ed25519 PKIX document

[Anders Rundgren <[e-mail]>]

On 2015-11-12 09:37, Simon Josefsson wrote:
> Anders Rundgren <[e-mail]> writes:
>
>> Pardon me for being somewhat unclear, I meant the distinction of EC versus ED.
> ...
>> Essentially the question is weather you extend EC or create a new type.
>
> Ah, now I understand.
>
> Well, the situation is that GnuTLS implements a new key type (see [1]
> but it should have more text) and there is ALSO the possibility of using
> the RFC 5915 ECPrivateKey together with the NamedCurve defined in [2]
> but it is a bit underspecified (see below).  I'm not negative about
> doing a PKCS#15 format in addition to this.
>
> The problem with re-using RFC 5915 is that has a number of references in
> it that doesn't make a lot of sense for EdDSA (e.g., it uses I2OSP from
> RSA for encoding!).  So it is not really clear how you would actually
> re-use the existing EC type for EdDSA since it is so tailored around how
> ECDSA works.  I assume this was the reason Nikos didn't re-use it but
> created a new simpler private key format for EdDSA.

This was (IMO) the right approach.

>
> To have more alignment, we could describe an ECPrivateKey structure for
> EdDSA keys that would be ASN.1-compatible but have different semantics
> that would work for EdDSA.  I'm not convinced that is worth the effort,
> as it will create implementation complexity and confusion.

Indeed.

Anders
>
> /Simon
>
> [1] https://tools.ietf.org/html/draft-josefsson-pkix-eddsa-04#section-8.3
> [2] https://tools.ietf.org/html/draft-josefsson-pkix-newcurves-01
>