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

From: Stephan Mueller
Date: Sun Oct 18 2015 - 18:06:28 EST


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@xxxxxxxxxx>
---
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


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