Subject: [Curdle] Comments regarding draft-ietf-curdle-pkix-07

From: Steffen Jaeckel <[email-masked]>
Date: Fri, 16 Feb 2018 16:22:45 +0100

Hi,

I'm currently adding curve25519 support to libtomcrypt.

That's why I've just read through
https://tools.ietf.org/html/draft-ietf-curdle-pkix-07 and I've got some
questions/comments:

# why don't you use the same public/private key throughout the examples?

that would make life easier to recognize what is where in which format

# why is there no ASN.1 dump of example 10.1?

# why are the examples in 10.3 not formatted the same way?

first example is like:

>    12 04   34:   OCTET STRING
>              :     04 20 D4 ...

second example is like:

>     12  34:   OCTET STRING, encapsulates {
>     14  32:     OCTET STRING D4 ...

# why is the private key an OCTET STRING in an OCTET STRING?

I already got pointed to
https://www.ietf.org/mail-archive/web/curdle/current/msg00572.html ff.
which also discusses this and I follow the opinion of Nikos to not carry
technical debt in the standard if it's already found before final
standardization. It shouldn't be the problem of later implementors that
there were some early adopters who implemented a non-standard version.

# a correction proposal to Ch. 8:

> When the curve is known, use the more specific string of X25519 or
> X448.

should be

> When the curve is known, use the more specific string of "X25519" or
> "X448".

Cheers,
Steffen
-- 
Steffen Jaeckel - [email-masked]
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