Bluetooth: Add key size checks for SMP

This patch implements a check in smp cmd pairing request and pairing
response to verify if encryption key maximum size is compatible in both
slave and master when SMP Pairing is requested. Keys are also masked to
the correct negotiated size.

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>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 157419afe532..bf1c7f681932 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -400,6 +400,7 @@ struct l2cap_conn {
         __u8            prnd[16]; /* SMP Pairing Random */
         __u8            pcnf[16]; /* SMP Pairing Confirm */
         __u8            tk[16]; /* SMP Temporary Key */
+        __u8            smp_key_size;
 
         struct timer_list security_timer;
 
diff --git a/include/net/bluetooth/smp.h b/include/net/bluetooth/smp.h
index 111853ab239a..4fb7d198a876 100644
--- a/include/net/bluetooth/smp.h
+++ b/include/net/bluetooth/smp.h
@@ -112,6 +112,9 @@ struct smp_cmd_security_req {
 #define SMP_UNSPECIFIED         0x08
 #define SMP_REPEATED_ATTEMPTS           0x09
 
+#define SMP_MIN_ENC_KEY_SIZE            7
+#define SMP_MAX_ENC_KEY_SIZE            16
+
 /* SMP Commands */
 int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level);
 int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb);