[PATCH 4.4 084/117] crypto: algif_skcipher - Add nokey compatibility path

Greg Kroah-Hartman
2016-02-15T00:27:40Z

From: Herbert Xu <herbert@gondor.apana.org.au>

commit a0fa2d037129a9849918a92d91b79ed6c7bd2818 upstream.

This patch adds a compatibility path to support old applications
that do acept(2) before setkey.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/algif_skcipher.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 144 insertions(+), 5 deletions(-)

--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -753,6 +753,99 @@ static struct proto_ops algif_skcipher_o
.poll = skcipher_poll,
};

+static int skcipher_check_key(struct socket *sock)
+{
+ int err;
+ struct sock *psk;
+ struct alg_sock *pask;
+ struct skcipher_tfm *tfm;
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+
+ if (ask->refcnt)
+ return 0;
+
+ psk = ask->parent;
+ pask = alg_sk(ask->parent);
+ tfm = pask->private;
+
+ err = -ENOKEY;
+ lock_sock(psk);
+ if (!tfm->has_key)
+ goto unlock;
+
+ if (!pask->refcnt++)
+ sock_hold(psk);
+
+ ask->refcnt = 1;
+ sock_put(psk);
+
+ err = 0;
+
+unlock:
+ release_sock(psk);
+
+ return err;
+}
+
+static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
+ size_t size)
+{
+ int err;
+
+ err = skcipher_check_key(sock);
+ if (err)
+ return err;
+
+ return skcipher_sendmsg(sock, msg, size);
+}
+
+static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
+ int offset, size_t size, int flags)
+{
+ int err;
+
+ err = skcipher_check_key(sock);
+ if (err)
+ return err;
+
+ return skcipher_sendpage(sock, page, offset, size, flags);
+}
+
+static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
+ size_t ignored, int flags)
+{
+ int err;
+
+ err = skcipher_check_key(sock);
+ if (err)
+ return err;
+
+ return skcipher_recvmsg(sock, msg, ignored, flags);
+}
+
+static struct proto_ops algif_skcipher_ops_nokey = {
+ .family = PF_ALG,
+
+ .connect = sock_no_connect,
+ .socketpair = sock_no_socketpair,
+ .getname = sock_no_getname,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .getsockopt = sock_no_getsockopt,
+ .mmap = sock_no_mmap,
+ .bind = sock_no_bind,
+ .accept = sock_no_accept,
+ .setsockopt = sock_no_setsockopt,
+
+ .release = af_alg_release,
+ .sendmsg = skcipher_sendmsg_nokey,
+ .sendpage = skcipher_sendpage_nokey,
+ .recvmsg = skcipher_recvmsg_nokey,
+ .poll = skcipher_poll,
+};
+
static void *skcipher_bind(const char *name, u32 type, u32 mask)
{
struct skcipher_tfm *tfm;
@@ -802,7 +895,7 @@ static void skcipher_wait(struct sock *s
msleep(100);
}

-static void skcipher_sock_destruct(struct sock *sk)
+static void skcipher_sock_destruct_common(struct sock *sk)
{
struct alg_sock *ask = alg_sk(sk);
struct skcipher_ctx *ctx = ask->private;
@@ -814,10 +907,33 @@ static void skcipher_sock_destruct(struc
skcipher_free_sgl(sk);
sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
sock_kfree_s(sk, ctx, ctx->len);
+}
+
+static void skcipher_sock_destruct(struct sock *sk)
+{
+ skcipher_sock_destruct_common(sk);
af_alg_release_parent(sk);
}

-static int skcipher_accept_parent(void *private, struct sock *sk)
+static void skcipher_release_parent_nokey(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+
+ if (!ask->refcnt) {
+ sock_put(ask->parent);
+ return;
+ }
+
+ af_alg_release_parent(sk);
+}
+
+static void skcipher_sock_destruct_nokey(struct sock *sk)
+{
+ skcipher_sock_destruct_common(sk);
+ skcipher_release_parent_nokey(sk);
+}
+
+static int skcipher_accept_parent_common(void *private, struct sock *sk)
{
struct skcipher_ctx *ctx;
struct alg_sock *ask = alg_sk(sk);
@@ -825,9 +941,6 @@ static int skcipher_accept_parent(void *
struct crypto_skcipher *skcipher = tfm->skcipher;
unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);

- if (!tfm->has_key)
- return -ENOKEY;
-
ctx = sock_kmalloc(sk, len, GFP_KERNEL);
if (!ctx)
return -ENOMEM;
@@ -861,12 +974,38 @@ static int skcipher_accept_parent(void *
return 0;
}

+static int skcipher_accept_parent(void *private, struct sock *sk)
+{
+ struct skcipher_tfm *tfm = private;
+
+ if (!tfm->has_key)
+ return -ENOKEY;
+
+ return skcipher_accept_parent_common(private, sk);
+}
+
+static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
+{
+ int err;
+
+ err = skcipher_accept_parent_common(private, sk);
+ if (err)
+ goto out;
+
+ sk->sk_destruct = skcipher_sock_destruct_nokey;
+
+out:
+ return err;
+}
+
static const struct af_alg_type algif_type_skcipher = {
.bind = skcipher_bind,
.release = skcipher_release,
.setkey = skcipher_setkey,
.accept = skcipher_accept_parent,
+ .accept_nokey = skcipher_accept_parent_nokey,
.ops = &algif_skcipher_ops,
+ .ops_nokey = &algif_skcipher_ops_nokey,
.name = "skcipher",
.owner = THIS_MODULE
};