Re: [PATCH v5 06/11] crypto: qce: skcipher: Return error for non-blocksize data(ECB/CBC algorithms)

[Thara Gopinath]

On 2/4/21 5:50 PM, Eric Biggers wrote:
> On Thu, Feb 04, 2021 at 04:43:54PM -0500, Thara Gopinath wrote:
> > +	/*
> > +	 * ECB and CBC algorithms require message lengths to be
> > +	 * multiples of block size.
> > +	 * TODO: The spec says AES CBC mode for certain versions
> > +	 * of crypto engine can handle partial blocks as well.
> > +	 * Test and enable such messages.
> > +	 */
> > +	if (IS_ECB(rctx->flags) || IS_CBC(rctx->flags))
> > +		if (!IS_ALIGNED(req->cryptlen, blocksize))
> > +			return -EINVAL;
>
> CBC by definition only operates on full blocks, so the TODO doesn't make sense.
> Is the partial block support really CTS-CBC?

Ya you are right. It should be CTS-CBC and not AES CBC. Though the spec 
is quite fuzzy about this part.

I can remove the comment and spin the next version or just leave it 
there for now and remove it later.

> - Eric

--
Warm Regards
Thara