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

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

Hi Mat,

Stephan,

On Sat, 14 May 2016, Tadeusz Struk wrote:

quoted

From: Stephan Mueller <redacted>

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 <redacted>
Signed-off-by: Tadeusz Struk <redacted>
---
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>

quoted

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

Regards,

--
Mat Martineau
Intel OTC

Ciao
Stephan