Bluetooth: Don't enforce authentication for L2CAP PSM 1 and 3

The recommendation for the L2CAP PSM 1 (SDP) is to not use any kind
of authentication or encryption. So don't trigger authentication
for incoming and outgoing SDP connections.

For L2CAP PSM 3 (RFCOMM) there is no clear requirement, but with
Bluetooth 2.1 the initiator is required to enable authentication
and encryption first and this gets enforced. So there is no need
to trigger an additional authentication step. The RFCOMM service
security will make sure that a secure enough link key is present.

When the encryption gets enabled after the SDP connection setup,
then switch the security level from SDP to low security.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

2 files changed, 7 insertions, 1 deletions

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index f75028b33883..9473fce499e7 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -597,6 +597,9 @@ static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status, __u8 encr
 {
         struct list_head *p;
 
+        if (conn->sec_level == BT_SECURITY_SDP)
+                conn->sec_level = BT_SECURITY_LOW;
+
         hci_proto_encrypt_cfm(conn, status, encrypt);
 
         read_lock_bh(&hci_cb_list_lock);
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 01f750142d55..88340d24d11d 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -805,7 +805,7 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_
                 l2cap_pi(sk)->sport = la->l2_psm;
                 sk->sk_state = BT_BOUND;
 
-                if (btohs(la->l2_psm) == 0x0001)
+                if (btohs(la->l2_psm) == 0x0001 || btohs(la->l2_psm) == 0x0003)
                         l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
         }
 
@@ -852,6 +852,9 @@ static int l2cap_do_connect(struct sock *sk)
                         auth_type = HCI_AT_NO_BONDING_MITM;
                 else
                         auth_type = HCI_AT_NO_BONDING;
+
+                if (l2cap_pi(sk)->sec_level == BT_SECURITY_LOW)
+                        l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
         } else {
                 switch (l2cap_pi(sk)->sec_level) {
                 case BT_SECURITY_HIGH: