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

Mat Martineau
2016-06-14T17:22:27Z

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?

<snip>

> +unlock:
> + akcipher_data_wakeup(sk);
> + release_sock(sk);
> +
> + return err ?: copied;
> +}

Regards,

--
Mat Martineau
Intel OTC