Re: [PATCH] crypto: ccree: fix iv copying for small buffers

[Herbert Xu]

On Sun, Jun 17, 2018 at 01:06:42PM +0300, Gilad Ben-Yossef wrote:
>
> It was ctr(aes). I wrongly assumed that we are supposed to unconditionally
> copy
> the cipher-text block post operation and let the caller do with it what it
> wants and so the
> code now does that for all cipher operations unconditionally.

For CTR it doesn't matter whether the last block is less than a
block, you should still increment the counter.

> So what is a good description of what we are supposed to provide in that
> field post operation?
> The next IV? but as you stated, that is not necessarily useful for all
> ciphers.

When in doubt, please refer to the generic implementation.  If
that is still unclear or if it seems wrong, please post to the
list.

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt