Added helper function for replayed security capabilities

srsue/hdr/stack/upper/nas_5g.h

@@ -134,10 +134,11 @@ private:
   int send_deregistration_request_ue_originating(bool switch_off);
   int send_identity_response(srsran::nas_5g::identity_type_5gs_t::identity_types_::options requested_identity_type);
 
+  // Helper functions
   void fill_security_caps(srsran::nas_5g::ue_security_capability_t& sec_caps);
   int  apply_security_config(srsran::unique_byte_buffer_t& pdu, uint8_t sec_hdr_type);
-  int  handle_deregistration_accept_ue_originating(
-       srsran::nas_5g::deregistration_accept_ue_originating_t& deregistration_accept_ue_originating);
+  bool check_replayed_ue_security_capabilities(srsran::nas_5g::ue_security_capability_t& caps);
+
   // message handler
   int handle_registration_accept(srsran::nas_5g::registration_accept_t& registration_accept);
   int handle_registration_reject(srsran::nas_5g::registration_reject_t& registration_reject);
@@ -150,6 +151,8 @@ private:
                                    srsran::unique_byte_buffer_t             pdu);
   int handle_deregistration_accept_ue_terminated(
       srsran::nas_5g::deregistration_accept_ue_terminated_t& deregistration_accept_ue_terminated);
+  int handle_deregistration_accept_ue_originating(
+      srsran::nas_5g::deregistration_accept_ue_originating_t& deregistration_accept_ue_originating);
   int handle_deregistration_request_ue_terminated(
       srsran::nas_5g::deregistration_request_ue_terminated_t& deregistration_request_ue_terminated);
   int handle_configuration_update_command(srsran::nas_5g::configuration_update_command_t& configuration_update_command);

srsue/src/stack/upper/nas_5g.cc

@@ -836,11 +836,10 @@ int nas_5g::handle_security_mode_command(security_mode_command_t&     security_m
   ctxt.integ_algo = (INTEGRITY_ALGORITHM_ID_ENUM)
                         security_mode_command.selected_nas_security_algorithms.integrity_protection_algorithm.value;
 
-  // Check capabilities
-  // TODO: Check replayed sec capabilities
-  if (!ea5g_caps[ctxt.cipher_algo] || !ia5g_caps[ctxt.integ_algo]) {
+  // Check replayed ue security capabilities
+  if (!check_replayed_ue_security_capabilities(security_mode_command.replayed_ue_security_capabilities)) {
     logger.warning("Sending Security Mode Reject due to security capabilities mismatch");
-    send_security_mode_reject(cause_5gmm_t::cause_5gmm_type_::options::ue_security_capabilities_mismatch);
+    send_security_mode_reject(cause_5gmm_t::cause_5gmm_type_::ue_security_capabilities_mismatch);
     return SRSRAN_ERROR;
   }
 
@@ -1056,6 +1055,36 @@ void nas_5g::fill_security_caps(srsran::nas_5g::ue_security_capability_t& sec_ca
   }
 }
 
+bool nas_5g::check_replayed_ue_security_capabilities(srsran::nas_5g::ue_security_capability_t& caps)
+{
+  if (caps.ia0_5g_supported != ia5g_caps[0] || caps.ea0_5g_supported != ea5g_caps[0]) {
+    return false;
+  }
+  if (caps.ia1_128_5g_supported != ia5g_caps[1] || caps.ea1_128_5g_supported != ea5g_caps[1]) {
+    return false;
+  }
+  if (caps.ia2_128_5g_supported != ia5g_caps[2] || caps.ea2_128_5g_supported != ea5g_caps[2]) {
+    return false;
+  }
+  if (caps.ia3_128_5g_supported != ia5g_caps[3] || caps.ea3_128_5g_supported != ea5g_caps[3]) {
+    return false;
+  }
+  if (caps.ia4_5g_supported != ia5g_caps[4] || caps.ea4_5g_supported != ea5g_caps[4]) {
+    return false;
+  }
+  if (caps.ia5_5g_supported != ia5g_caps[5] || caps.ea5_5g_supported != ea5g_caps[5]) {
+    return false;
+  }
+  if (caps.ia6_5g_supported != ia5g_caps[6] || caps.ea6_5g_supported != ea5g_caps[6]) {
+    return false;
+  }
+  if (caps.ia7_5g_supported != ia5g_caps[7] || caps.ea7_5g_supported != ea5g_caps[7]) {
+    return false;
+  }
+
+  return true;
+}
+
 /*******************************************************************************
  * Helpers for Session Management
  ******************************************************************************/