Re: [PATCH 1/2] crypto: sm3 - add a new alias name sm3-256

Eric Biggers
2020-02-10T18:36:25Z

[Please fix your email client; you dropped all non-list recipients from Cc,
and I had to manually add them back...]

On Mon, Feb 10, 2020 at 01:02:42PM -0500, Ken Goldman wrote:
> On 2/10/2020 12:01 PM, Van Leeuwen, Pascal wrote:
> > Well, the current specification surely doesn't define anything else and is
> > already over a decade old. So what would be the odds that they add a
> > different blocksize variant_now_ AND still call that SM3-something?
>
> I just got a note from a cryptographer who said there were discussions last
> year about a future SM3 with 512 bit output.
>
> Given that, why not plan ahead and use sm3-256? Is there any downside?
> Is the cost any more than 4 bytes in some source code?

If renaming sm3 to sm3-256 in the crypto API, no. If adding sm3-256 alongside
sm3, then yes there is a cost to that because from the crypto API's perspective
they will be separate algorithms that each need to be registered, tested, etc.

- Eric