Bluetooth: Add support for using the crypto subsystem
This will allow using the crypto subsystem for encrypting data. As SMP
(Security Manager Protocol) is implemented almost entirely on the host
side and the crypto module already implements the needed methods
(AES-128), it makes sense to use it.
There's now a new module option to enable/disable SMP support.
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index e14e8a1..f62ca19 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -42,6 +42,7 @@
#include <linux/notifier.h>
#include <linux/rfkill.h>
#include <linux/timer.h>
+#include <linux/crypto.h>
#include <net/sock.h>
#include <asm/system.h>
@@ -59,6 +60,8 @@
static DEFINE_RWLOCK(hci_task_lock);
+static int enable_smp;
+
/* HCI device list */
LIST_HEAD(hci_dev_list);
DEFINE_RWLOCK(hci_dev_list_lock);
@@ -1274,6 +1277,14 @@
return 0;
}
+static struct crypto_blkcipher *alloc_cypher(void)
+{
+ if (enable_smp)
+ return crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
+
+ return ERR_PTR(-ENOTSUPP);
+}
+
/* Register HCI device */
int hci_register_dev(struct hci_dev *hdev)
{
@@ -1358,6 +1369,11 @@
if (!hdev->workqueue)
goto nomem;
+ hdev->tfm = alloc_cypher();
+ if (IS_ERR(hdev->tfm))
+ BT_INFO("Failed to load transform for ecb(aes): %ld",
+ PTR_ERR(hdev->tfm));
+
hci_register_sysfs(hdev);
hdev->rfkill = rfkill_alloc(hdev->name, &hdev->dev,
@@ -1406,6 +1422,9 @@
!test_bit(HCI_SETUP, &hdev->flags))
mgmt_index_removed(hdev->id);
+ if (!IS_ERR(hdev->tfm))
+ crypto_free_blkcipher(hdev->tfm);
+
hci_notify(hdev, HCI_DEV_UNREG);
if (hdev->rfkill) {
@@ -2242,3 +2261,6 @@
}
}
}
+
+module_param(enable_smp, bool, 0644);
+MODULE_PARM_DESC(enable_smp, "Enable SMP support (LE only)");