[noise] Wording issue

[Trevor Perrin]

On Thu, Nov 12, 2015 at 5:28 PM, Alex <alex at centromere.net> wrote:
> It just occurred to me that for WriteMessage the spec says:
>
> For "e": Sets e = GENERATE_KEYPAIR(). Appends
> EncryptAndHash(e.public_key) to the buffer.
>
> If the user passes "new_e" to Initialize, it will immediately get
> overwritten when the "e" token is encountered. Is this intended?

Yes - this allows patterns where a server publishes a semi-ephemeral
value that the client uses for its initial message, but then the
server upgrades to a fresher ephemeral on its response.

I made the language more explicit about handling empty / non-empty
variables in WriteMessage / ReadMessage, e.g.:
"""
      * For "e":  Sets `e = GENERATE_KEYPAIR()`, overwriting any previous
        value for `e`.  Appends `EncryptAndHash(e.public_key)` to the buffer.
"""

Trevor