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

Stephan Mueller
2016-06-15T07:04:37Z

Am Dienstag, 14. Juni 2016, 10:22:15 schrieb Mat Martineau:

Hi Mat,

> Stephan,
>
> On Sat, 14 May 2016, Tadeusz Struk wrote:
> > From: Stephan Mueller <smueller@chronox.de>
> >
> > This patch adds the user space interface for asymmetric ciphers. The
> > interface allows the use of sendmsg as well as vmsplice to provide data.
> >
> > This version has been rebased on top of 4.6 and a few chackpatch issues
> > have been fixed.
> >
> > Signed-off-by: Stephan Mueller <smueller@chronox.de>
> > Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
> > ---
> > crypto/algif_akcipher.c | 542
> > +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 542
> > insertions(+)
> > create mode 100644 crypto/algif_akcipher.c
> >
> > diff --git a/crypto/algif_akcipher.c b/crypto/algif_akcipher.c
> > new file mode 100644
> > index 0000000..6342b6e
> > --- /dev/null
> > +++ b/crypto/algif_akcipher.c
> > +
> > +static int akcipher_sendmsg(struct socket *sock, struct msghdr *msg,
> > + size_t size)
> > +{
> > + struct sock *sk = sock->sk;
> > + struct alg_sock *ask = alg_sk(sk);
> > + struct akcipher_ctx *ctx = ask->private;
> > + struct akcipher_sg_list *sgl = &ctx->tsgl;
> > + struct af_alg_control con = {};
> > + long copied = 0;
> > + int op = 0;
> > + bool init = 0;
> > + int err;
> > +
> > + if (msg->msg_controllen) {
> > + err = af_alg_cmsg_send(msg, &con);
> > + if (err)
> > + return err;
> > +
> > + init = 1;
> > + switch (con.op) {
> > + case ALG_OP_VERIFY:
> > + case ALG_OP_SIGN:
> > + case ALG_OP_ENCRYPT:
> > + case ALG_OP_DECRYPT:
> > + op = con.op;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > + }
> > +
> > + lock_sock(sk);
> > + if (!ctx->more && ctx->used)
> > + goto unlock;
>
> err might be uninitialised at this goto. Should it be set to something
> like -EALREADY to indicate that data is already queued for a different
> crypto op?

Thanks for the hint. Tadeusz, I will provide you with an updated
algif_akcipher.c for your patchset.

I will also have a look at the comment from Andrew.

>
> <snip>
>
> > +unlock:
> > + akcipher_data_wakeup(sk);
> > + release_sock(sk);
> > +
> > + return err ?: copied;
> > +}
>
> Regards,
>
> --
> Mat Martineau
> Intel OTC

Ciao
Stephan