Merge pull request #7688 from paul-szczepanek-arm/nrf-ltk-fix

BLE: call secure connections versions of ltk functions

Author: Cruz Monrreal

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF52/source/nRF5xPalSecurityManager.cpp

@@ -760,6 +760,24 @@ nRF5xSecurityManager& nRF5xSecurityManager::get_security_manager()
     return _security_manager;
 }
 
+/**
+ * EDIV and Rand are invalid if both are zero
+ */
+bool is_ediv_rand_valid(const uint16_t ediv, const uint8_t* rand)
+{
+    for (int i = 0; i < BLE_GAP_SEC_RAND_LEN; ++i) {
+        if (rand[i]) {
+            return true;
+        }
+    }
+
+    if (ediv != 0) {
+        return true;
+    }
+
+    return false;
+}
+
 bool nRF5xSecurityManager::sm_handler(const ble_evt_t *evt)
 {
     nRF5xSecurityManager& self = nRF5xSecurityManager::get_security_manager();
@@ -846,11 +864,17 @@ bool nRF5xSecurityManager::sm_handler(const ble_evt_t *evt)
             const ble_gap_evt_sec_info_request_t& req =
                 gap_evt.params.sec_info_request;
 
-            handler->on_ltk_request(
-                connection,
-                ediv_t((uint8_t*)(&req.master_id.ediv)),
-                rand_t(req.master_id.rand)
-            );
+            if (is_ediv_rand_valid(req.master_id.ediv, req.master_id.rand)) {
+                handler->on_ltk_request(
+                    connection,
+                    ediv_t((uint8_t*)(&req.master_id.ediv)),
+                    rand_t(req.master_id.rand)
+                );
+            } else {
+                /* no valid EDIV and Rand
+                 * request ltk generated with secure connection */
+                handler->on_ltk_request(connection);
+            }
 
             return true;
         }
@@ -948,33 +972,46 @@ bool nRF5xSecurityManager::sm_handler(const ble_evt_t *evt)
                         peer_dist = pairing_cb->initiator_dist;
                     }
 
-                    if (own_dist.get_encryption()) {
-                        handler->on_keys_distributed_local_ltk(
-                            connection,
-                            ltk_t(pairing_cb->own_enc_key.enc_info.ltk)
-                        );
-
-                        handler->on_keys_distributed_local_ediv_rand(
-                            connection,
-                            ediv_t(reinterpret_cast<uint8_t*>(
-                                &pairing_cb->own_enc_key.master_id.ediv
-                            )),
+                    if (is_ediv_rand_valid(
+                            pairing_cb->own_enc_key.master_id.ediv,
                             pairing_cb->own_enc_key.master_id.rand
-                        );
-                    }
-
-                    if (peer_dist.get_encryption()) {
-                        handler->on_keys_distributed_ltk(
-                            connection,
-                            ltk_t(pairing_cb->peer_enc_key.enc_info.ltk)
-                        );
+                        )
+                    ) {
+                        if (own_dist.get_encryption()) {
+                            handler->on_keys_distributed_local_ltk(
+                                connection,
+                                ltk_t(pairing_cb->own_enc_key.enc_info.ltk)
+                            );
+
+                            handler->on_keys_distributed_local_ediv_rand(
+                                connection,
+                                ediv_t(reinterpret_cast<uint8_t*>(
+                                    &pairing_cb->own_enc_key.master_id.ediv
+                                )),
+                                pairing_cb->own_enc_key.master_id.rand
+                            );
+                        }
 
-                        handler->on_keys_distributed_ediv_rand(
+                        if (peer_dist.get_encryption()) {
+                            handler->on_keys_distributed_ltk(
+                                connection,
+                                ltk_t(pairing_cb->peer_enc_key.enc_info.ltk)
+                            );
+
+                            handler->on_keys_distributed_ediv_rand(
+                                connection,
+                                ediv_t(reinterpret_cast<uint8_t*>(
+                                    &pairing_cb->peer_enc_key.master_id.ediv
+                                )),
+                                pairing_cb->peer_enc_key.master_id.rand
+                            );
+                        }
+                    } else {
+                        /* no valid EDIV and Rand meaning this is a
+                         * Secure Connections key */
+                        handler->on_secure_connections_ltk_generated(
                             connection,
-                            ediv_t(reinterpret_cast<uint8_t*>(
-                                &pairing_cb->peer_enc_key.master_id.ediv
-                            )),
-                            pairing_cb->peer_enc_key.master_id.rand
+                            ltk_t(pairing_cb->own_enc_key.enc_info.ltk)
                         );
                     }