Re: [PATCH v6 3/6] crypto: AF_ALG -- add asymmetric cipher interface

[Mat Martineau]

On Thu, 9 Jun 2016, Stephan Mueller wrote:

> Am Donnerstag, 9. Juni 2016, 11:18:04 schrieb Mat Martineau:
>
> Hi Mat,
>
> > > Or is your concern that the user space interface restricts things too much
> > > and thus prevents a valid use case?
> >
> > The latter - my primary concern is the constraint this places on userspace
> > by forcing larger buffer sizes than might be necessary for the operation.
> > struct akcipher_request has separate members for src_len and dst_len, and
> > dst_len is documented as needing "to be at least as big as the expected
> > result depending on the operation". Not the maximum result, the expected
> > result. It's also documented that the cipher will generate an error if
> > dst_len is insufficient and update the value with the required size.
> >
> > I'm updating some userspace TLS code that worked with an earlier, unmerged
> > patch set for AF_ALG akcipher (from last year). The read calls with
> > shorter buffers were the main porting problem.
>
> I see -- are you proposing to drop that check entirely?

Yes.


Best regards,

--
Mat Martineau
Intel OTC