add config option and documentation

daemon/web/src/lib/components/ConfigForm.svelte

@@ -183,6 +183,18 @@
                                 Null Cipher Heuristic
                             </label>
                         </div>
+
+                        <div class="flex items-center">
+                            <input
+                                id="nas_null_cipher"
+                                type="checkbox"
+                                bind:checked={config.analyzers.nas_null_cipher}
+                                class="h-4 w-4 text-rayhunter-blue focus:ring-rayhunter-blue border-gray-300 rounded"
+                            />
+                            <label for="nas_null_cipher" class="ml-2 block text-sm text-gray-700">
+                                NAS Null Cipher Heuristic
+                            </label>
+                        </div>
                     </div>
                 </div>
 

daemon/web/src/lib/utils.svelte.ts

@@ -6,6 +6,7 @@ export interface AnalyzerConfig {
     connection_redirect_2g_downgrade: boolean;
     lte_sib6_and_7_downgrade: boolean;
     null_cipher: boolean;
+    nas_null_cipher: boolean;
 }
 
 export interface Config {

dist/config.toml.example

@@ -27,4 +27,5 @@ key_input_mode = 0
 imsi_requested = true
 connection_redirect_2g_downgrade = true
 lte_sib6_and_7_downgrade = true
-null_cipher = true
+null_cipher = true 
+nas_null_cipher = true

doc/heuristics.md

@@ -20,3 +20,4 @@ Rayhunter includes several analyzers to detect potential IMSI catcher activity.
 - **LTE SIB6/7 Downgrade**: Tests for LTE cells broadcasting a SIB type 6 and 7
   which include 2G/3G frequencies with higher priorities
 - **Null Cipher**: Tests whether the cell suggests using a null cipher (EEA0).
+- **NAS Null Cipher**: Tests whether the security mode command at the NAS layer suggests using a null cipher (EEA0). This would usually only happen after a UE has successfully authenticated with the MME but still it shouldn't happen at all, this could be indicative of an attack though using SS7 to get key material from the HLR of the UE for a succesful authentication. It could also indicate an IMSI catcher which is connected to the mobile network MME and HLR through cooperation between government and telco. Or it could be a false positive if the telco is intending to use null ciphers (if encryption is illegal or something.)