rename to diagnostic and add docs

2026-04-27 16:09:58 -07:00 · 2026-02-05 14:29:46 -08:00
parent f7759721e3
commit 184f4bd7a2
6 changed files with 19 additions and 16 deletions
--- a/lib/src/analysis/diagnostic.rs
+++ b/lib/src/analysis/diagnostic.rs
@@ -0,0 +1,152 @@
+use crate::analysis::analyzer::{Analyzer, Event, EventType};
+use crate::analysis::information_element::{InformationElement, LteInformationElement};
+use pycrate_rs::nas::NASMessage;
+use pycrate_rs::nas::emm::EMMMessage;
+use pycrate_rs::nas::generated::emm::emm_attach_reject::EMMCauseEMMCause as AttachRejectEMMCause;
+use pycrate_rs::nas::generated::emm::emm_attach_request::EPSAttachTypeV;
+use pycrate_rs::nas::generated::emm::emm_detach_request_mt::EPSDetachTypeMTType;
+use pycrate_rs::nas::generated::emm::emm_identity_request::IDTypeV;
+use pycrate_rs::nas::generated::emm::emm_service_reject::EMMCauseEMMCause as ServiceRejectEMMCause;
+use pycrate_rs::nas::generated::emm::emm_tracking_area_update_reject::EMMCauseEMMCause as TAURejectEMMCause;
+use std::borrow::Cow;
+
+pub struct DiagnosticAnalyzer;
+
+impl DiagnosticAnalyzer {
+    pub fn new() -> Self {
+        DiagnosticAnalyzer
+    }
+
+    fn is_imsi_exposing_nas(&self, nas_msg: &NASMessage) -> bool {
+        match nas_msg {
+            NASMessage::EMMMessage(emm_msg) => match emm_msg {
+                EMMMessage::EMMIdentityRequest(req) => req.id_type.inner == IDTypeV::IMSI,
+
+                EMMMessage::EMMTrackingAreaUpdateReject(reject) => {
+                    matches!(
+                        reject.emm_cause.inner,
+                        TAURejectEMMCause::IllegalUE
+                            | TAURejectEMMCause::IllegalME
+                            | TAURejectEMMCause::EPSServicesNotAllowed
+                            | TAURejectEMMCause::EPSServicesAndNonEPSServicesNotAllowed
+                            | TAURejectEMMCause::TrackingAreaNotAllowed
+                            | TAURejectEMMCause::EPSServicesNotAllowedInThisPLMN
+                            | TAURejectEMMCause::RequestedServiceOptionNotAuthorizedInThisPLMN
+                    )
+                }
+
+                EMMMessage::EMMAttachReject(reject) => {
+                    matches!(
+                        reject.emm_cause.inner,
+                        AttachRejectEMMCause::IllegalUE
+                            | AttachRejectEMMCause::IllegalME
+                            | AttachRejectEMMCause::EPSServicesNotAllowed
+                            | AttachRejectEMMCause::EPSServicesAndNonEPSServicesNotAllowed
+                            | AttachRejectEMMCause::PLMNNotAllowed
+                            | AttachRejectEMMCause::TrackingAreaNotAllowed
+                            | AttachRejectEMMCause::RoamingNotAllowedInThisTrackingArea
+                            | AttachRejectEMMCause::EPSServicesNotAllowedInThisPLMN
+                            | AttachRejectEMMCause::NoSuitableCellsInTrackingArea
+                            | AttachRejectEMMCause::RequestedServiceOptionNotAuthorizedInThisPLMN
+                    )
+                }
+
+                EMMMessage::EMMDetachRequestMT(req) => {
+                    // Original implementation: !(nas_eps.emm.detach_type_dl == 3)
+                    req.eps_detach_type.inner.typ != EPSDetachTypeMTType::IMSIDetach
+                }
+
+                EMMMessage::EMMAttachRequest(req) => {
+                    req.eps_attach_type.inner == EPSAttachTypeV::CombinedEPSIMSIAttach
+                }
+
+                EMMMessage::EMMServiceReject(reject) => {
+                    matches!(
+                        reject.emm_cause.inner,
+                        ServiceRejectEMMCause::IllegalUE
+                            | ServiceRejectEMMCause::IllegalME
+                            | ServiceRejectEMMCause::EPSServicesNotAllowed
+                            | ServiceRejectEMMCause::UEIdentityCannotBeDerivedByTheNetwork
+                            | ServiceRejectEMMCause::TrackingAreaNotAllowed
+                            | ServiceRejectEMMCause::EPSServicesNotAllowedInThisPLMN
+                            | ServiceRejectEMMCause::RequestedServiceOptionNotAuthorizedInThisPLMN
+                    )
+                }
+
+                _ => false,
+            },
+            _ => false,
+        }
+    }
+}
+
+impl Analyzer for DiagnosticAnalyzer {
+    fn get_name(&self) -> Cow<'_, str> {
+        "Diagnostic detector for messages which might lead to IMSI exposure".into()
+    }
+
+    fn get_description(&self) -> Cow<'_, str> {
+        "Catches any messages that may lead to IMSI Exposure. Can be quite noisy. \
+        Useful as a diagnostic for finding out why an IMSI was sent or what \
+        the reason for a reject message was. Not a useful indicator on its own \
+        but a helpful diagnostic for understanding why another indicator was \
+        triggered. Based on the list of IMSI exposing messages identified in \
+        the 'Marlin' paper.".into()
+    }
+
+    fn get_version(&self) -> u32 {
+        1
+    }
+
+    fn analyze_information_element(
+        &mut self,
+        ie: &InformationElement,
+        _packet_num: usize,
+    ) -> Option<Event> {
+        let lte_ie = match ie {
+            InformationElement::LTE(inner) => inner,
+            _ => return None,
+        };
+
+        match lte_ie.as_ref() {
+            LteInformationElement::NAS(nas_msg) => {
+                if self.is_imsi_exposing_nas(nas_msg) {
+                    let message_type = match nas_msg {
+                        NASMessage::EMMMessage(emm_msg) => {
+                            match emm_msg {
+                                EMMMessage::EMMIdentityRequest(request) => {
+                                    format!("EMM Identity Request ({:?})", request.id_type.inner)
+                                }
+                                EMMMessage::EMMTrackingAreaUpdateReject(reject) => {
+                                    format!("EMM Tracking Area Update Reject ({:?})", reject.emm_cause.inner )
+                                }
+                                EMMMessage::EMMAttachReject(reject) => {
+                                    format!("EMM Attach Reject ({:?})", reject.emm_cause.inner)
+                                }
+                                EMMMessage::EMMDetachRequestMT(request) => {
+                                    format!("EMM Detach Request ({:?}:{:?})", request.eps_detach_type.inner, request.emm_cause.inner)
+                                }
+                                EMMMessage::EMMServiceReject(reject) => {
+                                    format!("EMM Service Reject ({:?})", reject.emm_cause.inner )
+                                }
+                                EMMMessage::EMMAttachRequest(request) => {
+                                    format!("EPS Attach Request ({:?})", request.eps_attach_type.inner )
+                                }
+                                _ => "Unknown EMM Message".to_string(),
+                            }
+                        }
+                        _ => "Unknown NAS Message".to_string(),
+                    };
+
+                    Some(Event {
+                        event_type: EventType::Informational,
+                        message: format!("Diagnostic: {message_type}."),
+                    })
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        }
+    }
+}