re-enable null cipher and update docs

doc/heuristics.md

@@ -10,6 +10,4 @@ Rayhunter includes several analyzers to detect potential IMSI catcher activity.
   makes sense in the US, European users may want to disable it.
 - **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** (disabled by default): Tests whether the cell suggests using a null cipher (EEA0).
-  This is currently disabled by default due to a parsing bug triggering false
-  positives.
+- **Null Cipher**: Tests whether the cell suggests using a null cipher (EEA0).

lib/src/analysis/analyzer.rs

@@ -26,10 +26,7 @@ impl Default for AnalyzerConfig {
             imsi_requested: true,
             connection_redirect_2g_downgrade: true,
             lte_sib6_and_7_downgrade: true,
-            // FIXME: our RRC parser is reporting false positives for this due to an
-            // upstream hampi bug (https://github.com/ystero-dev/hampi/issues/133).
-            // once that's fixed, we should regenerate our parser and re-enable this
-            null_cipher: false,
+            null_cipher: true,
         }
     }
 }

telcom-parser/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+# FIXME: When this branch is merged into main point this at the release version of hampi again
 asn1-compiler = { git = "https://github.com/ystero-dev/hampi", rev = "67f3283764eda20022d190c3d3d6edd1a88047e0" }
 asn1-codecs = { git = "https://github.com/ystero-dev/hampi", rev = "67f3283764eda20022d190c3d3d6edd1a88047e0" }
 asn1_codecs_derive = { git = "https://github.com/ystero-dev/hampi", rev = "67f3283764eda20022d190c3d3d6edd1a88047e0" }