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

[Stephan Mueller <smueller@chronox.de>]

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 <smueller@chronox.de>
---
 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, keylen);
 
 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 authsize);
 
-- 
2.5.0