Re: [TLS] Curve25519 in TLS and Additional Curves in TLS

[Manuel Pégourié-Gonnard <[e-mail]>]

On 03/04/2014 08:03, Andrey Jivsov wrote:
> The ECPoint is defined as follows,
> 
>             struct {
>                 opaque point <1..2^8-1>;
>             } ECPoint;
> 
> Is the format on the wire per section 2.3
>     33 32 xx xx xx ... xx
> or, suggested,
>     65 64 xx xx xx ... xx yy yy yy ... yy ?
> 
> Or I am reading it incorrectly and the extra byte mentioned in the draft 
> is actully a part of standard TLS encoding of the length byte?
> 
The intention of the current draft is that the wire format be

32 xx xx ... xx

So the "additional length byte" is indeed just the one from the TLS encoding.

In the next iteration of the draft, it might change to

33 tt xx xx .. xx

Where tt would be an "encoding type" which would allow for future extensions
like transmitting y too, or a bit of y, or (parts of) other representation (eg
Edwards coordinates).

Manuel.