chore: release v0.4.2-beta.4 on beta

Sha256::digest() is a trait method (from digest::Digest, re-exported as
sha2::Digest), not an inherent one - fully-qualifying the call
(sha2::Sha256::digest(...)) doesn't exempt it from Rust's requirement that
the trait itself be in scope for method resolution. Whatever made this
resolve locally without the explicit import didn't reproduce on the CI
runner's dependency resolution, breaking `cargo check` and killing the
whole v0.4.2-beta.3 matrix before a single platform job even started.
Added the import; harmless even where it isn't strictly needed.

.github/workflows/release.yml

@@ -284,7 +284,15 @@ jobs:
 
       - name: Install cross (if not cached)
         if: ${{ matrix.use_cross && steps.cross-cache.outputs.cache-hit != 'true' }}
-        run: cargo install cross --git https://github.com/cross-rs/cross.git --locked
+        # cross-rs's own source (not ours, not a dependency of ours) uses a
+        # macro-at-end-of-block pattern that trips rustc's
+        # semicolon_in_expressions_from_macros lint on current toolchains -
+        # harmless in cross's actual behavior, but `cargo install` compiles
+        # the installed package as the "local" crate, so dependency lint
+        # capping doesn't shield it. --cap-lints=warn is the standard escape
+        # hatch for building a third-party tool against a newer compiler than
+        # its own lint config assumed; it doesn't touch our own build.
+        run: RUSTFLAGS="--cap-lints=warn" cargo install cross --git https://github.com/cross-rs/cross.git --locked
 
       - name: Build (cross)
         if: ${{ matrix.use_cross }}

.release-state.json

@@ -2,5 +2,5 @@
   "target_version": "0.4.2",
   "branch": "beta",
   "alpha_iteration": 0,
-  "beta_iteration": 2
+  "beta_iteration": 4
 }

Cargo.lock

@@ -1400,6 +1400,7 @@ dependencies = [
  "rlimit",
  "serde",
  "serde_json",
+ "sha2",
  "tokio",
  "tracing",
  "tracing-subscriber",
@@ -1496,6 +1497,7 @@ dependencies = [
  "sha2",
  "simple-dns",
  "socket2",
+ "subtle",
  "tokio",
  "tower-http",
  "tracing",

ostp-client/src/bridge.rs

@@ -231,7 +231,7 @@ impl Bridge {
                     self.handle_inbound_udp(udp_msg, &mut sessions_opt, &mut udp_rx_opt, &mut proxy_guard, &mut stream_map, &tx, &proxy_tx).await;
                 }
                 cmd = bridge_rx.recv() => {
-                    if !self.handle_bridge_cmd(cmd, &mut sessions_opt, &mut udp_rx_opt, &mut proxy_guard, &mut stream_map, &tx, &proxy_tx).await {
+                    if !self.handle_bridge_cmd(cmd, &mut bridge_rx, &mut sessions_opt, &mut udp_rx_opt, &mut proxy_guard, &mut stream_map, &tx, &proxy_tx).await {
                         break;
                     }
                 }
@@ -374,6 +374,7 @@ impl Bridge {
     async fn handle_bridge_cmd(
         &mut self,
         cmd: Option<BridgeCommand>,
+        bridge_rx: &mut mpsc::Receiver<BridgeCommand>,
         sessions_opt: &mut Option<Vec<SessionState>>,
         udp_rx_opt: &mut Option<mpsc::Receiver<(usize, Bytes)>>,
         proxy_guard: &mut Option<crate::sysproxy::SystemProxyGuard>,
@@ -465,6 +466,32 @@ impl Bridge {
                 tx.send(UiEvent::Log(format!("Obfuscation profile switched to {:?}", self.profile))).await.ok();
             }
             Some(BridgeCommand::NetworkChanged) => {
+                // A real network handoff (Wi-Fi <-> cellular) commonly fires
+                // onLost + onAvailable within milliseconds of each other on
+                // Android, queuing several NetworkChanged commands back to
+                // back. Each reconnect below is a full sequential handshake
+                // (up to ~1.2s x 4 attempts x mux_sessions) run synchronously
+                // in this select-loop iteration, so without coalescing, the
+                // first attempt often races the OS's own network switch and
+                // fails on the now-dead interface, then the SECOND queued
+                // NetworkChanged only starts its own full reconnect after
+                // that first one finishes - multiplying a sub-second handoff
+                // into many seconds of extra outage. Drain same-kind repeats
+                // so a burst collapses into one reconnect on the freshest
+                // signal; a different command found while draining is
+                // handled immediately rather than dropped.
+                while let Ok(next) = bridge_rx.try_recv() {
+                    if !matches!(next, BridgeCommand::NetworkChanged) {
+                        let more = Box::pin(self.handle_bridge_cmd(
+                            Some(next), bridge_rx, sessions_opt, udp_rx_opt, proxy_guard, stream_map, tx, proxy_tx,
+                        )).await;
+                        if !more {
+                            return false;
+                        }
+                        break;
+                    }
+                }
+
                 if self.running {
                     let _ = tx.send(UiEvent::Log("Network changed — starting immediate reconnect".to_string())).await;
                     self.metrics.connection_state.store(1, Ordering::Relaxed);

ostp-client/src/tunnel/proxy.rs

@@ -361,6 +361,10 @@ async fn handle_udp_associate(
 
     let mut direct_udp_v4: Option<Arc<UdpSocket>> = None;
     let mut direct_udp_v6: Option<Arc<UdpSocket>> = None;
+    // Held only to keep the direct-UDP readers' cancellation senders alive;
+    // dropping this (on every return path from this function) is what tells
+    // spawn_direct_udp_reader's tasks to stop. See its doc comment.
+    let mut direct_udp_cancel_txs: Vec<tokio::sync::oneshot::Sender<()>> = Vec::new();
 
     let mut tcp_buf = [0u8; 1];
     loop {
@@ -432,7 +436,9 @@ async fn handle_udp_associate(
                                     match create_udp_socket_bypassing_tun(true, matcher.physical_if_index, &matcher.physical_if_name).await {
                                         Ok(s) => {
                                             let s_arc = Arc::new(s);
-                                            spawn_direct_udp_reader(s_arc.clone(), sock_tx.clone(), client_udp_addr.clone(), debug);
+                                            let (cancel_tx, cancel_rx) = tokio::sync::oneshot::channel();
+                                            spawn_direct_udp_reader(s_arc.clone(), sock_tx.clone(), client_udp_addr.clone(), debug, cancel_rx);
+                                            direct_udp_cancel_txs.push(cancel_tx);
                                             direct_udp_v6 = Some(s_arc);
                                         }
                                         Err(e) => {
@@ -446,7 +452,9 @@ async fn handle_udp_associate(
                                     match create_udp_socket_bypassing_tun(false, matcher.physical_if_index, &matcher.physical_if_name).await {
                                         Ok(s) => {
                                             let s_arc = Arc::new(s);
-                                            spawn_direct_udp_reader(s_arc.clone(), sock_tx.clone(), client_udp_addr.clone(), debug);
+                                            let (cancel_tx, cancel_rx) = tokio::sync::oneshot::channel();
+                                            spawn_direct_udp_reader(s_arc.clone(), sock_tx.clone(), client_udp_addr.clone(), debug, cancel_rx);
+                                            direct_udp_cancel_txs.push(cancel_tx);
                                             direct_udp_v4 = Some(s_arc);
                                         }
                                         Err(e) => {
@@ -520,11 +528,24 @@ fn spawn_direct_udp_reader(
     sock_tx: Arc<UdpSocket>,
     client_udp_addr: Arc<std::sync::Mutex<Option<std::net::SocketAddr>>>,
     _debug: bool,
+    mut cancel_rx: tokio::sync::oneshot::Receiver<()>,
 ) {
     tokio::spawn(async move {
         let mut buf = vec![0u8; 65536];
         loop {
-            match direct_socket.recv_from(&mut buf).await {
+            let recv_result = tokio::select! {
+                // Fires as soon as the sender half (held by handle_udp_associate
+                // for exactly this reason) is dropped - which happens the
+                // instant that function returns, on every exit path, with no
+                // explicit signaling needed. Without this, a UDP-associate
+                // session that ever bypassed traffic direct (excluded IP/
+                // domain) leaked this socket + task for the rest of the
+                // process's life once the session ended: nothing else ever
+                // stopped this loop.
+                _ = &mut cancel_rx => break,
+                res = direct_socket.recv_from(&mut buf) => res,
+            };
+            match recv_result {
                 Ok((len, target_addr)) => {
                     let client_addr = {
                         let guard = client_udp_addr.lock().unwrap();

ostp-client/src/tunnel/udp_nat.rs

@@ -138,27 +138,34 @@ async fn start_udp_bypass_session(
         let _ = crate::tunnel::proxy::bind_socket_to_interface(&socket, name);
     }
 
-    let socket = Arc::new(socket);
+    // A single select! loop over both directions, rather than spawning a
-    let socket_rx = socket.clone();
+    // separate task for the read side, so the whole session - physical
-
+    // socket included - is torn down the moment this function returns
-    // Spawn a task to read from physical socket and send back to smoltcp
+    // (e.g. when session_rx closes). The previous spawned-task version left
-    let tx_clone = smoltcp_tx.clone();
+    // that task (and its Arc<UdpSocket> clone, keeping the OS socket fd
-    tokio::spawn(async move {
+    // alive) running forever after this function returned: nothing ever
+    // cancelled it, so every bypassed UDP flow (any excluded app/IP in TUN
+    // mode) leaked one socket + one task for the lifetime of the process.
     use futures::SinkExt;
     let mut buf = [0u8; 65536];
     loop {
-            match socket_rx.recv_from(&mut buf).await {
+        tokio::select! {
+            outbound = session_rx.recv() => {
+                match outbound {
+                    Some((payload, dst)) => { socket.send_to(&payload, dst).await?; }
+                    None => break,
+                }
+            }
+            inbound = socket.recv_from(&mut buf) => {
+                match inbound {
                     Ok((n, peer)) => {
-                    let mut lock = tx_clone.lock().await;
+                        let mut lock = smoltcp_tx.lock().await;
                         let _ = lock.send((buf[..n].to_vec(), peer, client_src)).await;
                     }
                     Err(_) => break,
                 }
             }
-    });
+        }
-
-    while let Some((payload, dst)) = session_rx.recv().await {
-        socket.send_to(&payload, dst).await?;
     }
 
     Ok(())

ostp-core/src/congestion.rs

@@ -43,6 +43,11 @@ pub struct CongestionController {
     mtu: u64,
     /// Min RTT expiry: re-probe after 10 seconds
     min_rtt_stamp: Instant,
+    /// Loss events counted toward SLOW_START_LOSS_TOLERANCE within the
+    /// current SLOW_START_LOSS_WINDOW (see on_loss's SlowStart arm).
+    slow_start_losses: u32,
+    /// Start of the current loss-tolerance window.
+    slow_start_loss_window_start: Instant,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -67,6 +72,24 @@ const RTO_MAX: Duration = Duration::from_secs(16);
 /// Will be replaced by first real measurement within milliseconds.
 const INITIAL_RTT: Duration = Duration::from_millis(30);
 
+/// Isolated packet loss during slow start (a single dropped frame from
+/// wireless noise, a brief LTE handover blip, etc.) is normal on real
+/// mobile/Wi-Fi links and does NOT mean the link is congested. The previous
+/// behavior exited slow start and halved cwnd on the very FIRST loss, which
+/// on any link with a non-zero background loss rate permanently downgrades
+/// the session from exponential growth to linear (+1 MTU/RTT) ProbeBandwidth
+/// growth within the first few RTTs - turning what should be a sub-second
+/// ramp-up into tens of seconds to minutes before throughput opens up
+/// (observed as: a trickle of KB/s, then a sudden jump once cwnd finally
+/// claws back up). Only treat loss as a real congestion signal - and pay
+/// the full slow-start-exit + halving cost - once this many losses land
+/// within SLOW_START_LOSS_WINDOW.
+const SLOW_START_LOSS_TOLERANCE: u32 = 3;
+/// Window within which SLOW_START_LOSS_TOLERANCE losses must land to count
+/// as sustained (rather than isolated) loss. Roughly a few RTTs on a
+/// well-connected link, generous on a slow one.
+const SLOW_START_LOSS_WINDOW: Duration = Duration::from_millis(500);
+
 impl CongestionController {
     pub fn new(mtu: u64) -> Self {
         let now = Instant::now();
@@ -88,6 +111,8 @@ impl CongestionController {
             pacing_rate: initial_pacing,
             mtu,
             min_rtt_stamp: now,
+            slow_start_losses: 0,
+            slow_start_loss_window_start: now,
         }
     }
 
@@ -197,11 +222,28 @@ impl CongestionController {
 
         match self.phase {
             Phase::SlowStart => {
-                // Exit slow start, set ssthresh to half of cwnd
+                let now = Instant::now();
+                if now.duration_since(self.slow_start_loss_window_start) > SLOW_START_LOSS_WINDOW {
+                    // Previous window's losses have aged out - this loss starts a fresh count.
+                    self.slow_start_losses = 0;
+                    self.slow_start_loss_window_start = now;
+                }
+                self.slow_start_losses += 1;
+
+                if self.slow_start_losses >= SLOW_START_LOSS_TOLERANCE {
+                    // Sustained loss within the window: treat as real congestion.
+                    // Exit slow start, set ssthresh to half of cwnd.
                     self.ssthresh = self.cwnd / 2;
                     self.cwnd = self.ssthresh.max(MIN_CWND_PACKETS * self.mtu);
                     self.phase = Phase::ProbeBandwidth;
-                tracing::debug!(cwnd = self.cwnd, ssthresh = self.ssthresh, "congestion: loss during slow start");
+                    tracing::debug!(cwnd = self.cwnd, ssthresh = self.ssthresh, "congestion: sustained loss during slow start, exiting");
+                } else {
+                    // Isolated loss: likely non-congestive noise. Take a mild,
+                    // temporary haircut but keep exponential growth going -
+                    // don't throw away slow start over a single dropped frame.
+                    self.cwnd = (self.cwnd * 8 / 10).max(MIN_CWND_PACKETS * self.mtu);
+                    tracing::debug!(cwnd = self.cwnd, count = self.slow_start_losses, "congestion: isolated loss during slow start, staying in slow start");
+                }
             }
             Phase::ProbeBandwidth => {
                 // Multiplicative decrease: cwnd *= 0.7 (BBR-style, less aggressive than Cubic's 0.5)
@@ -290,6 +332,50 @@ mod tests {
         assert!(cc.cwnd() < initial);
     }
 
+    #[test]
+    fn test_isolated_slow_start_loss_does_not_exit_slow_start() {
+        // A single dropped packet (wireless noise, a brief handover blip) is
+        // normal on real links and must not permanently downgrade the
+        // session from exponential to linear growth.
+        let mut cc = CongestionController::new(1200);
+        cc.on_loss(1200);
+        assert_eq!(cc.phase, Phase::SlowStart, "one isolated loss must not exit slow start");
+
+        // It should still shrink the window somewhat (not ignored entirely),
+        // just far less punishing than the sustained-congestion case.
+        let after_one = cc.cwnd();
+        assert!(after_one < INITIAL_CWND_PACKETS * 1200);
+    }
+
+    #[test]
+    fn test_sustained_slow_start_loss_exits_slow_start() {
+        // Losses landing close together (within SLOW_START_LOSS_WINDOW) are
+        // a real congestion signal and must still trigger the harsher
+        // exit-slow-start + halve response.
+        let mut cc = CongestionController::new(1200);
+        for _ in 0..SLOW_START_LOSS_TOLERANCE {
+            cc.on_loss(1200);
+        }
+        assert_eq!(cc.phase, Phase::ProbeBandwidth, "sustained loss must exit slow start");
+    }
+
+    #[test]
+    fn test_slow_start_loss_window_resets_after_expiry() {
+        // Two losses far enough apart (window expired between them) must
+        // each be treated as isolated, not accumulated toward the sustained-
+        // loss threshold.
+        let mut cc = CongestionController::new(1200);
+        cc.on_loss(1200);
+        assert_eq!(cc.phase, Phase::SlowStart);
+
+        // Simulate the window having expired by resetting its start
+        // directly (std::thread::sleep in a unit test would be flaky/slow).
+        cc.slow_start_loss_window_start = Instant::now() - SLOW_START_LOSS_WINDOW - Duration::from_millis(1);
+        cc.on_loss(1200);
+        assert_eq!(cc.phase, Phase::SlowStart, "a loss after the window expired must restart the count, not accumulate");
+        assert_eq!(cc.slow_start_losses, 1);
+    }
+
     #[test]
     fn test_can_send_limits() {
         let mut cc = CongestionController::new(1200);

ostp-flutter/pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 0.4.2+21
+version: 0.4.2+23
 
 environment:
   sdk: ^3.11.4

ostp-server/Cargo.toml

@@ -31,3 +31,4 @@ hex = "0.4.3"
 chacha20poly1305.workspace = true
 x25519-dalek = { version = "2.0.1", features = ["static_secrets"] }
 chrono = "0.4.44"
+subtle = "2.6"

ostp-server/src/api.rs

@@ -318,6 +318,18 @@ pub async fn start_api_server(
 
 // ── Middleware: token check ──────────────────────────────────────────────────
 
+/// Constant-time string equality for secrets (tokens, password hashes).
+/// Plain `==` short-circuits on the first differing byte, which leaks how
+/// many leading bytes an attacker's guess got right through response
+/// timing - a classic remote timing side-channel against exactly the kind
+/// of long-lived bearer/session secrets compared here. `subtle` is already
+/// pulled in transitively (chacha20poly1305 etc.); pinning it as a direct
+/// dependency here makes that guarantee explicit for this call site.
+fn secure_eq(a: &str, b: &str) -> bool {
+    use subtle::ConstantTimeEq;
+    a.as_bytes().ct_eq(b.as_bytes()).into()
+}
+
 fn check_token(state: &ApiState, headers: &axum::http::HeaderMap) -> bool {
     // Both session token (for web UI) and static API token (for relays) are checked
     let mut allowed = false;
@@ -332,19 +344,19 @@ fn check_token(state: &ApiState, headers: &axum::http::HeaderMap) -> bool {
             if let Some(token) = val.strip_prefix("Bearer ") {
                 let current_session = state.session_token.read().unwrap_or_else(|e| e.into_inner()).clone();
                 if let Some(session) = current_session {
-                    if token == session {
+                    if secure_eq(token, &session) {
                         allowed = true;
                     }
                 }
 
                 if let Some(ref api_tok) = state.api_token {
-                    if token == api_tok {
+                    if secure_eq(token, api_tok) {
                         allowed = true;
                     }
                 }
             } else {
                 if let Some(ref api_tok) = state.api_token {
-                    if val == api_tok {
+                    if secure_eq(val, api_tok) {
                         allowed = true;
                     }
                 }
@@ -371,7 +383,7 @@ async fn handle_login(
     let hash = sha2::Sha256::digest(password.as_bytes());
     let hash_hex = format!("{:x}", hash);
 
-    if hash_hex == state.password_hash {
+    if secure_eq(&hash_hex, &state.password_hash) {
         let token = uuid::Uuid::new_v4().to_string();
         *state.session_token.write().unwrap_or_else(|e| e.into_inner()) = Some(token.clone());
         (StatusCode::OK, ApiResponse::success(LoginResponse { token }))
@@ -881,15 +893,91 @@ mod tests {
         let state = make_test_state("");
         let _router = create_api_router(state);
     }
+
+    #[test]
+    fn test_secure_eq_matches_and_rejects() {
+        assert!(secure_eq("same-secret", "same-secret"));
+        assert!(!secure_eq("same-secret", "different"));
+        assert!(!secure_eq("short", "much-longer-value"));
+        assert!(secure_eq("", ""));
     }
 
-async fn handle_get_audit(State(state): State<ApiState>) -> impl IntoResponse {
+    fn headers_with_bearer(token: &str) -> axum::http::HeaderMap {
-    let logs = state.audit_logs.read().unwrap();
+        let mut h = axum::http::HeaderMap::new();
-    ApiResponse::success(logs.clone())
+        h.insert("authorization", format!("Bearer {token}").parse().unwrap());
+        h
     }
 
-async fn handle_create_audit(State(state): State<ApiState>, Json(req): Json<CreateAuditLogRequest>) -> impl IntoResponse {
+    // These pin down check_token's behavior directly: it's the single gate
-    let mut logs = state.audit_logs.write().unwrap();
+    // every mutating/sensitive handler (including the audit-log ones - see
+    // the missing-auth fix) relies on, so its logic must be independently
+    // verified rather than only exercised incidentally through handlers.
+    #[test]
+    fn test_check_token_rejects_missing_header_when_configured() {
+        let state = make_test_state("panel");
+        assert!(!check_token(&state, &axum::http::HeaderMap::new()));
+    }
+
+    #[test]
+    fn test_check_token_accepts_matching_api_token_as_bearer() {
+        let state = make_test_state("panel");
+        assert!(check_token(&state, &headers_with_bearer("test-token")));
+    }
+
+    #[test]
+    fn test_check_token_accepts_matching_api_token_raw() {
+        let state = make_test_state("panel");
+        let mut h = axum::http::HeaderMap::new();
+        h.insert("authorization", "test-token".parse().unwrap());
+        assert!(check_token(&state, &h));
+    }
+
+    #[test]
+    fn test_check_token_rejects_wrong_token() {
+        let state = make_test_state("panel");
+        assert!(!check_token(&state, &headers_with_bearer("wrong-token")));
+    }
+
+    #[test]
+    fn test_check_token_accepts_matching_session_token() {
+        let state = make_test_state("panel");
+        *state.session_token.write().unwrap() = Some("live-session".to_string());
+        assert!(check_token(&state, &headers_with_bearer("live-session")));
+    }
+
+    #[test]
+    fn test_check_token_open_when_no_credentials_configured() {
+        let mut state = make_test_state("panel");
+        state.api_token = None;
+        state.username.clear();
+        state.password_hash.clear();
+        // Documented "unsafe but possible" open-panel mode: no credentials
+        // configured at all means every request passes, including with no
+        // Authorization header.
+        assert!(check_token(&state, &axum::http::HeaderMap::new()));
+    }
+}
+
+async fn handle_get_audit(
+    State(state): State<ApiState>,
+    headers: axum::http::HeaderMap,
+) -> impl IntoResponse {
+    if !check_token(&state, &headers) {
+        return api_unauthorized::<Vec<AuditLogEntry>>();
+    }
+    let logs = state.audit_logs.read().unwrap_or_else(|e| e.into_inner());
+    (StatusCode::OK, ApiResponse::success(logs.clone()))
+}
+
+async fn handle_create_audit(
+    State(state): State<ApiState>,
+    headers: axum::http::HeaderMap,
+    Json(req): Json<CreateAuditLogRequest>,
+) -> impl IntoResponse {
+    if !check_token(&state, &headers) {
+        return api_unauthorized::<bool>();
+    }
+    let mut logs = state.audit_logs.write().unwrap_or_else(|e| e.into_inner());
     let id = format!("{:x}", rand::random::<u64>());
     let now = chrono::Local::now();
     let entry = AuditLogEntry {
@@ -904,7 +992,7 @@ async fn handle_create_audit(State(state): State<ApiState>, Json(req): Json<Crea
         logs.truncate(100);
     }
 
-    ApiResponse::success(true)
+    (StatusCode::OK, ApiResponse::success(true))
 }
 
 // ── Bulk keys & Router Rules ─────────────────────────────────────────────────
@@ -1006,10 +1094,16 @@ async fn handle_put_rules(
     (StatusCode::OK, ApiResponse::success(true))
 }
 
-async fn handle_clear_audit(State(state): State<ApiState>) -> impl IntoResponse {
+async fn handle_clear_audit(
-    let mut logs = state.audit_logs.write().unwrap();
+    State(state): State<ApiState>,
+    headers: axum::http::HeaderMap,
+) -> impl IntoResponse {
+    if !check_token(&state, &headers) {
+        return api_unauthorized::<()>();
+    }
+    let mut logs = state.audit_logs.write().unwrap_or_else(|e| e.into_inner());
     logs.clear();
-    ApiResponse::success(())
+    (StatusCode::OK, ApiResponse::success(()))
 }
 
 

ostp-server/src/dns.rs

@@ -276,6 +276,18 @@ impl DnsServer {
     ///
     /// Клиент может явно указать `<server_ip>:<local_port>` как DNS-сервер
     /// в настройках — тогда все DNS-запросы туннелируются и резолвятся здесь.
+    ///
+    /// SECURITY: this socket is bound on 0.0.0.0, reachable directly from the
+    /// public internet with no authentication (unlike the main OSTP port,
+    /// there is no Noise handshake gating it). Answering every UDP datagram
+    /// by resolving and replying to its (unverified, spoofable) source
+    /// address is a textbook DNS reflection/amplification primitive: an
+    /// attacker spoofing a victim's IP as the query source turns this server
+    /// into a free amplifier against that victim. There is currently no
+    /// caller for this function anywhere in the codebase, but the rate
+    /// limiter below exists so that connecting it later doesn't silently
+    /// reintroduce that risk - it bounds how much amplification bandwidth
+    /// this listener can ever contribute, regardless of query volume.
     pub async fn run_local_udp_listener(self: Arc<Self>) {
         let port = self.config.read().await.local_port;
         let bind_addr = format!("0.0.0.0:{port}");
@@ -289,10 +301,30 @@ impl DnsServer {
         };
         tracing::info!("Built-in DNS server listening on UDP {bind_addr}");
 
+        // Global token bucket capping total replies/sec this listener will
+        // ever send. Deliberately global (not per-source-IP): per-IP limiting
+        // does nothing against a reflection attack, since the attacker never
+        // sees the responses and can spread queries across arbitrarily many
+        // spoofed sources anyway. A global cap bounds this server's total
+        // contribution to any attack regardless of how the queries are
+        // distributed.
+        const MAX_REPLIES_PER_SEC: f64 = 100.0;
+        let mut tokens: f64 = MAX_REPLIES_PER_SEC;
+        let mut last_refill = tokio::time::Instant::now();
+
         let mut buf = vec![0u8; 4096];
         loop {
             match socket.recv_from(&mut buf).await {
                 Ok((n, peer)) => {
+                    let now = tokio::time::Instant::now();
+                    tokens = (tokens + now.duration_since(last_refill).as_secs_f64() * MAX_REPLIES_PER_SEC)
+                        .min(MAX_REPLIES_PER_SEC);
+                    last_refill = now;
+                    if tokens < 1.0 {
+                        continue; // over budget: drop silently, no reply sent
+                    }
+                    tokens -= 1.0;
+
                     let query = buf[..n].to_vec();
                     let srv = self.clone();
                     let sock = socket.clone();

ostp/Cargo.toml

@@ -21,3 +21,4 @@ tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 ostp-core = { path = "../ostp-core" }
 colored = "2.1"
 rlimit = "0.11.0"
+sha2.workspace = true

ostp/src/main.rs

@@ -3,6 +3,7 @@ use clap::Parser;
 use std::fs;
 use std::path::PathBuf;
 use colored::Colorize;
+use sha2::Digest;
 
 #[derive(Parser, Debug)]
 #[command(author, version, about = "OSTP Core - Ospab Stealth Transport Protocol", long_about = None)]
@@ -720,24 +721,11 @@ fn run_setup_wizard(config_path: &std::path::Path) -> Result<()> {
                 }) as char
             }).collect();
             let password  = wizard_prompt("Admin password (blank for random)", &rand_pass);
-            let pass_hash = {
+            // Must match api.rs's handle_login exactly (format!("{:x}", Sha256::digest(..))) -
-                use std::fmt::Write as _;
+            // this used to be a DefaultHasher (SipHash) placeholder that produced a
-                let mut hash = String::new();
+            // differently-shaped digest, so a password set up through this wizard could
-                let digest: [u8; 32] = {
+            // never actually log into the panel it just configured.
-                    use std::collections::hash_map::DefaultHasher;
+            let pass_hash = format!("{:x}", sha2::Sha256::digest(password.as_bytes()));
-                    use std::hash::{Hash, Hasher};
-                    // Panel password hashing. sha2 is not a direct dep of ostp/Cargo.toml,
-                    // so we use std's hasher as a placeholder digest here.
-                    let mut h = DefaultHasher::new();
-                    password.hash(&mut h);
-                    let v = h.finish();
-                    let mut out = [0u8; 32];
-                    out[..8].copy_from_slice(&v.to_be_bytes());
-                    out
-                };
-                for b in digest { let _ = write!(hash, "{:02x}", b); }
-                hash
-            };
 
             wizard_step(4, TOTAL, "Saving configuration");
             let panel_bind = format!("0.0.0.0:{}", panel_port);