[PATCH v4 2/7] crypto: AF_ALG -- add setpubkey setsockopt call

From: Tadeusz Struk
Date: Thu Mar 31 2016 - 21:42:58 EST


From: Stephan Mueller <smueller@xxxxxxxxxx>

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>
Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
---
crypto/af_alg.c | 18 +++++++++++++-----
include/crypto/if_alg.h | 1 +
2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index f5e18c2..24dc082 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -202,13 +202,17 @@ unlock:
}

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

+ if (!setkey)
+ return -ENOPROTOOPT;
+
key = sock_kmalloc(sk, keylen, GFP_KERNEL);
if (!key)
return -ENOMEM;
@@ -217,7 +221,7 @@ 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);
+ err = setkey(ask->private, key, keylen);

out:
sock_kzfree_s(sk, key, keylen);
@@ -247,10 +251,14 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
case ALG_SET_KEY:
if (sock->state == SS_CONNECTED)
goto unlock;
- if (!type->setkey)
+
+ err = alg_setkey(sk, optval, optlen, type->setkey);
+ break;
+ case ALG_SET_PUBKEY:
+ if (sock->state == SS_CONNECTED)
goto unlock;

- err = alg_setkey(sk, optval, optlen);
+ err = alg_setkey(sk, optval, optlen, type->setpubkey);
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 a2bfd78..6c3e6e7 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -52,6 +52,7 @@ 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 (*accept_nokey)(void *private, struct sock *sk);
int (*setauthsize)(void *private, unsigned int authsize);