chanserv: FLAGS maps sop/halfop presets to flag letters (oa=+ao), fixing privilege escalation when editing a HOP/SOP entry

api/src/lib.rs

@@ -676,8 +676,10 @@ pub fn level_caps(level: &str) -> Caps {
         "voice" => Caps { auto: Some("+v"), rank: Rank::Voice, ..Caps::default() },
         flags => {
             let has = |c: char| flags.contains(c);
+            // Auto-op plus access-list management is the SOP tier — it auto-gets
+            // protect + op (+ao), so a flag entry "oa" matches the "sop" preset.
             let auto = if has('o') {
-                Some("+o")
+                if has('a') { Some("+ao") } else { Some("+o") }
             } else if has('h') {
                 Some("+h")
             } else if has('v') {
@@ -1725,6 +1727,15 @@ mod tests {
         // and founder (+qo) over everything.
         assert_eq!(level_caps("sop").union(level_caps("voice")).auto, Some("+ao"));
         assert_eq!(level_caps("founder").union(level_caps("sop")).auto, Some("+qo"));
+
+        // The FLAGS display maps presets to flag letters that round-trip: the flag
+        // string resolves to the very same caps (op+access "oa" = the SOP tier,
+        // auto +ao), so FLAGS-editing a preset entry can't corrupt it.
+        for (preset, flags) in [("sop", "otia"), ("op", "oti"), ("halfop", "h"), ("voice", "v")] {
+            assert_eq!(level_caps(flags).auto, level_caps(preset).auto, "{preset} auto");
+            assert_eq!(level_caps(flags).rank, level_caps(preset).rank, "{preset} rank");
+        }
+        assert_eq!(level_caps("oa").auto, Some("+ao"), "op + access = protected admin");
     }
 
     #[test]

modules/chanserv/src/flags.rs

@@ -69,12 +69,17 @@ pub fn handle(me: &str, from: &Sender, chan: &str, args: &[&str], ctx: &mut Serv
     }
 }
 
-// Show a stored level as flag letters (mapping the legacy presets).
+// Show a stored level as flag letters, mapping the tier presets to their
+// equivalent flags so FLAGS can round-trip and edit them. Each mapping resolves
+// to the same capabilities as the preset (see `level_caps`): sop = op + topic +
+// invite + access (auto +ao), op = op + topic + invite, halfop = auto +h.
 fn display_flags(level: &str) -> String {
     match level {
-        "op" => "oti".to_string(),
-        "voice" => "v".to_string(),
         "founder" => "f".to_string(),
+        "sop" => "otia".to_string(),
+        "op" => "oti".to_string(),
+        "halfop" => "h".to_string(),
+        "voice" => "v".to_string(),
         flags => flags.to_string(),
     }
 }

src/engine/tests.rs

@@ -1459,6 +1459,38 @@
         assert!(kicked(&out) && !blocked(&out), "SOP can kick an AOP: {out:?}");
     }
 
+    // Regression: FLAGS-editing a HOP/SOP entry must not corrupt it. Adding +v to a
+    // halfop once escalated them to founder — the preset name "halfop" got reparsed
+    // as flags (f,o,h,a — 'f' = founder). It must stay in the halfop tier.
+    #[test]
+    fn flags_edit_of_a_preset_entry_does_not_escalate() {
+        use echo_chanserv::ChanServ;
+        use echo_nickserv::NickServ;
+        let path = std::env::temp_dir().join("echo-flagsesc.jsonl");
+        let _ = std::fs::remove_file(&path);
+        let mut db = Db::open(&path, "42S");
+        db.scram_iterations = 4096;
+        db.register("alice", "sesame", None).unwrap();
+        db.register("bob", "sesame", None).unwrap();
+        db.register_channel("#c", "alice").unwrap();
+        db.access_add("#c", "bob", "halfop").unwrap();
+        let mut e = Engine::new(
+            vec![
+                Box::new(NickServ { uid: "42SAAAAAA".into(), guest_nick: "Guest".into(), guest_seq: 0 }),
+                Box::new(ChanServ { uid: "42SAAAAAB".into() }),
+            ],
+            db,
+        );
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAB".into(), nick: "alice".into(), host: "h".into(), ip: "0.0.0.0".into() });
+        e.handle(NetEvent::Privmsg { from: "000AAAAAB".into(), to: "42SAAAAAA".into(), text: "IDENTIFY sesame".into() });
+        e.handle(NetEvent::Privmsg { from: "000AAAAAB".into(), to: "42SAAAAAB".into(), text: "FLAGS #c bob +v".into() });
+
+        let ci = e.db.channel("#c").unwrap();
+        assert!(!ci.is_op("bob"), "halfop + voice must not gain op or founder");
+        let lvl = ci.access.iter().find(|a| a.account == "bob").unwrap().level.clone();
+        assert!(!lvl.contains('f'), "must not acquire the founder flag: got {lvl:?}");
+    }
+
     // NickServ LIST is auspex-gated and glob-matches; UPDATE refreshes a session.
     #[test]
     fn nickserv_list_and_update() {