Re: [PATCH v2 3/5] crypto: AF_ALG -- add setpubkey setsockopt call

For supporting asymmetric ciphers, user space must be able to set the
public key. The patch adds a new setsockopt call for setting the public
key.

Signed-off-by: Stephan Mueller <redacted>
---
crypto/af_alg.c         | 14 +++++++++++---
include/crypto/if_alg.h |  1 +
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index a8e7aa3..bf6528e 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c

@@ -173,13 +173,16 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)

}

static int alg_setkey(struct sock *sk, char __user *ukey,
-		      unsigned int keylen)
+		      unsigned int keylen, bool pubkey)
{
	struct alg_sock *ask = alg_sk(sk);
	const struct af_alg_type *type = ask->type;
	u8 *key;
	int err;

+	if (pubkey && !type->setpubkey)
+		return -EOPNOTSUPP;
+
	key = sock_kmalloc(sk, keylen, GFP_KERNEL);
	if (!key)
		return -ENOMEM;

@@ -188,7 +191,10 @@ static int alg_setkey(struct sock *sk, char __user *ukey,

	if (copy_from_user(key, ukey, keylen))
		goto out;

-	err = type->setkey(ask->private, key, keylen);
+	if (pubkey)
+		err = type->setpubkey(ask->private, key, keylen);
+	else
+		err = type->setkey(ask->private, key, keyless);

out:
	sock_kzfree_s(sk, key, keylen);

@@ -212,12 +218,14 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,

	switch (optname) {
	case ALG_SET_KEY:
+	case ALG_SET_PUBKEY:
		if (sock->state == SS_CONNECTED)
			goto unlock;
		if (!type->setkey)
			goto unlock;

-		err = alg_setkey(sk, optval, optlen);
+		err = alg_setkey(sk, optval, optlen,
+				 (optname == ALG_SET_PUBKEY) ? true : false);
		break;

	case ALG_SET_AEAD_AUTHSIZE:
		if (sock->state == SS_CONNECTED)

diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index 018afb2..ca4dc72 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h

@@ -49,6 +49,7 @@ struct af_alg_type {

	void *(*bind)(const char *name, u32 type, u32 mask);
	void (*release)(void *private);
	int (*setkey)(void *private, const u8 *key, unsigned int keylen);
+	int (*setpubkey)(void *private, const u8 *key, unsigned int keylen);
	int (*accept)(void *private, struct sock *sk);
	int (*setauthsize)(void *private, unsigned int authorize);