GAP: gap_set_security_level sets required security level for incoming and outgoing connections

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 - example/le_mitm: MITM implementation that forwards ATT PDUs and allows for pairing
+- GAP: gap_set_security_level sets required security level for incoming and outgoing connections
 
 ### Changed
 - L2CAP ERTM: send extended features request only once per HCI connection

src/classic/avdtp_sink.c

@@ -120,7 +120,7 @@ void avdtp_sink_init(avdtp_context_t * avdtp_context){
     avdtp_sink_context->stream_endpoints_id_counter = 0;
     avdtp_sink_context->packet_handler = packet_handler;
 
-    l2cap_register_service(&packet_handler, BLUETOOTH_PSM_AVDTP, 0xffff, LEVEL_2);
+    l2cap_register_service(&packet_handler, BLUETOOTH_PSM_AVDTP, 0xffff, gap_get_security_level());
 }
 
 avdtp_stream_endpoint_t * avdtp_sink_create_stream_endpoint(avdtp_sep_type_t sep_type, avdtp_media_type_t media_type){

src/classic/avdtp_source.c

@@ -176,7 +176,7 @@ void avdtp_source_init(avdtp_context_t * avdtp_context){
     avdtp_source_context->stream_endpoints_id_counter = 0;
     avdtp_source_context->packet_handler = packet_handler;
 
-    l2cap_register_service(&packet_handler, BLUETOOTH_PSM_AVDTP, 0xffff, LEVEL_2);
+    l2cap_register_service(&packet_handler, BLUETOOTH_PSM_AVDTP, 0xffff, gap_get_security_level());
 }
 
 

src/classic/avrcp.c

@@ -823,7 +823,7 @@ void avrcp_init(void){
     connections = NULL;
     if (l2cap_service_registered) return;
 
-    int status = l2cap_register_service(&avrcp_packet_handler, BLUETOOTH_PSM_AVCTP, 0xffff, LEVEL_2);
+    int status = l2cap_register_service(&avrcp_packet_handler, BLUETOOTH_PSM_AVCTP, 0xffff, gap_get_security_level());
     if (status != ERROR_CODE_SUCCESS) return;
     l2cap_service_registered = 1;
 }

src/classic/avrcp_browsing_controller.c

@@ -695,7 +695,7 @@ static void avrcp_browsing_controller_packet_handler(uint8_t packet_type, uint16
 
 void avrcp_browsing_controller_init(void){
     avrcp_controller_context.browsing_packet_handler = avrcp_browsing_controller_packet_handler;
-    l2cap_register_service(&avrcp_browsing_controller_packet_handler, PSM_AVCTP_BROWSING, 0xffff, LEVEL_2);
+    l2cap_register_service(&avrcp_browsing_controller_packet_handler, PSM_AVCTP_BROWSING, 0xffff, gap_get_security_level());
 }
 
 void avrcp_browsing_controller_register_packet_handler(btstack_packet_handler_t callback){

src/classic/avrcp_browsing_target.c

@@ -393,7 +393,7 @@ static void avrcp_browsing_target_packet_handler(uint8_t packet_type, uint16_t c
 
 void avrcp_browsing_target_init(void){
     avrcp_target_context.browsing_packet_handler = avrcp_browsing_target_packet_handler;
-    l2cap_register_service(&avrcp_browsing_target_packet_handler, PSM_AVCTP_BROWSING, 0xffff, LEVEL_2);
+    l2cap_register_service(&avrcp_browsing_target_packet_handler, PSM_AVCTP_BROWSING, 0xffff, gap_get_security_level());
 }
 
 void avrcp_browsing_target_register_packet_handler(btstack_packet_handler_t callback){

src/classic/bnep.c

@@ -1567,7 +1567,7 @@ static void bnep_handle_can_send_now(uint16_t l2cap_cid){
 /* BNEP BTStack API */
 void bnep_init(void)
 {
-    bnep_security_level = LEVEL_2;
+    bnep_security_level = gap_get_security_level();
 }
 
 void bnep_set_required_security_level(gap_security_level_t security_level)

src/classic/bnep.h

@@ -194,6 +194,7 @@ int bnep_set_multicast_filter(uint16_t bnep_cid, bnep_multi_filter_t *filter, ui
 
 /**
  * @brief Set security level required for incoming connections, need to be called before registering services.
+ * @deprecated use gap_set_security_level instead
  */
 void bnep_set_required_security_level(gap_security_level_t security_level);
 

src/classic/hid_device.c

@@ -851,8 +851,8 @@ void hid_device_init(uint8_t boot_protocol_mode_supported, uint16_t descriptor_l
     hci_device_set_report = dummy_set_report;
     hci_device_report_data = dummy_report_data;
 
-    l2cap_register_service(packet_handler, PSM_HID_INTERRUPT, 100, LEVEL_2);
-    l2cap_register_service(packet_handler, PSM_HID_CONTROL,   100, LEVEL_2);                                      
+    l2cap_register_service(packet_handler, PSM_HID_INTERRUPT, 100, gap_get_security_level());
+    l2cap_register_service(packet_handler, PSM_HID_CONTROL,   100, gap_get_security_level());
 }
 
 /**

src/classic/rfcomm.c

@@ -2186,7 +2186,7 @@ void rfcomm_init(void){
     rfcomm_multiplexers = NULL;
     rfcomm_services     = NULL;
     rfcomm_channels     = NULL;
-    rfcomm_security_level = LEVEL_2;
+    rfcomm_security_level = gap_get_security_level();
 }
 
 void rfcomm_set_required_security_level(gap_security_level_t security_level){

src/classic/rfcomm.h

@@ -274,6 +274,7 @@ void rfcomm_init(void);
 
 /** 
  * @brief Set security level required for incoming connections, need to be called before registering services.
+ * @deprecated use gap_set_security_level instead
  */
 void rfcomm_set_required_security_level(gap_security_level_t security_level);
 

src/gap.h

@@ -188,13 +188,24 @@ void gap_set_bondable_mode(int enabled);
  */
 int gap_get_bondable_mode(void);
 
+/**
+ * @brief Set security level for all outgoing and incoming connections. Default: LEVEL_2
+ * @param security_level
+ * @note has to be called before services or profiles are initialized
+ */
+void gap_set_security_level(gap_security_level_t security_level);
+
+/**
+ * @brief Get security level
+ * @return security_level
+ */
+gap_security_level_t gap_get_security_level(void);
+
 /**
  * @brief Register filter for rejecting classic connections. Callback will return 1 accept connection, 0 on reject.
  */
-
 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr));
 
-
 /* Configure Secure Simple Pairing */
 
 /**

src/hci.c

@@ -2886,6 +2886,9 @@ void hci_init(const hci_transport_t *transport, const void *config){
     // Allow Role Switch
     hci_stack->allow_role_switch = 1;
 
+    // Default / minimum security level = 2
+    hci_stack->gap_security_level = LEVEL_2;
+
     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3, we use 16 as default
     hci_stack->gap_required_encyrption_key_size = 16;
 #endif
@@ -2982,6 +2985,14 @@ void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
     if (encryption_key_size > 16) return;
     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
 }
+
+void gap_set_security_level(gap_security_level_t security_level){
+    hci_stack->gap_security_level = security_level;
+}
+
+gap_security_level_t gap_get_security_level(void){
+    return hci_stack->gap_security_level;
+}
 #endif
 
 #ifdef ENABLE_CLASSIC

src/hci.h

@@ -771,6 +771,7 @@ typedef struct {
     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3, we use 16 as default
     uint8_t            gap_required_encyrption_key_size;
     uint16_t           link_supervision_timeout;
+    gap_security_level_t gap_security_level;
 #endif
 
     // single buffer for HCI packet assembly + additional prebuffer for H4 drivers

src/l2cap.c

@@ -1925,8 +1925,8 @@ static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * ch
     if (l2cap_security_level_0_allowed_for_PSM(channel->psm) == 0){
         // request security level 2
         channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE;
-        channel->required_security_level = LEVEL_2;
-        gap_request_security_level(channel->con_handle, LEVEL_2);
+        channel->required_security_level = gap_get_security_level();
+        gap_request_security_level(channel->con_handle, gap_get_security_level());
         return;
     }