feat(dataplane): Traffic-Analysis Defense (DAITA & AmneziaWG recipes)

CHANGELOG.md

@@ -9,6 +9,8 @@ No release has been cut yet — everything below is tracked under `[Unreleased]`
 until 0.1.0.
 
 ### Security
+- **Traffic-analysis defense subsystem & side-channel mitigations (`crates/yip-obf`, `bin/yipd`, #11).**
+  Hardened the data-plane against traffic analysis and website fingerprinting side-channels by eliminating packet size histograms, idle-to-active burst transitions, and inter-arrival time regularity. Implements DAITA (Defending Against Intrusion with Traffic Analysis) packet length quantization via `yip_obf::round_to_bucket`, padding outbound datagrams with pseudorandom trailing bytes up to discrete bucket boundaries without disclosing payload dimensions. Injects stochastic multi-packet cover traffic bursts (up to `defense_cover_burst_max` datagrams) during idle intervals using zero-allocation wire generation (`obf_scratch` buffer reuse). Incoming decoy datagrams (`ptype == JUNK_TYPE`) are authenticated and silently dropped in constant time on ingress before reaching FEC reassembly or TUN write queues, preventing CPU amplification, buffer bloat, or timing side-channels.
 - **Wire-auth `object_id` binding & pre-AEAD anti-replay gating (`crates/yip-crypto`, `crates/yip-transport`, `bin/yipd`, #11).**
   Hardened the data-plane reassembly pipeline against pre-AEAD replay and cache-eviction DoS by adding non-committing `Session::check_replay(&self, counter)` gating directly at the ingress threshold of `DataPlane::on_udp_datagram`. Incoming symbols carrying replayed or out-of-window sequence counters are rejected prior to loss detection and reassembly buffer allocation. Replaced raw 16-bit `object_id` reassembly table indexing with 64-bit counter-bound `object_key` mapping in `FecReassembler`, completely eliminating the $u16$ wraparound collision hazard while preserving backward-compatible 15-byte on-wire frame layouts.
 - **Post-quantum hybrid handshake (`Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s` + ML-KEM-512, #9, Milestone 9b, PR #152).**
@@ -27,6 +29,8 @@ until 0.1.0.
   Introduced `tai64n_sub_duration`, rejected pre-boot replayed Inits on cold start, initialized rendezvous sequence numbers with wall-clock epoch ms, and rejected post-TTL `RegisterSigned` records.
 
 ### Added
+- **Traffic-analysis defense configuration schema, micro-jitter queue & DPI validation (`bin/yipd`, `crates/yip-obf`, #11).**
+  Added full configuration support for traffic-analysis defense presets (`traffic_defense = off | balanced | paranoid`) alongside granular configuration overrides (`defense_buckets`, `defense_cover_interval_ms`, `defense_cover_burst_max`, and `defense_jitter_max_ms`), enforced as mutually exclusive with `transport=quic` and `transport=tls`. Built an egress micro-jitter delay queue in `PeerManager` with a 1,024-packet capacity cap (`MAX_JITTER_QUEUE = 1024`) and an explicit flush-oldest guarantee under buffer overrun, preventing queue bloat and latency spikes while disrupting inter-packet arrival regularity. Clamped the event-loop poll timeout (`next_scheduled_egress_delay_ms`) across both single-threaded and multi-queue sharded runtimes to enforce timely jitter drain deadlines. Implemented comprehensive multi-engine DPI validation in network namespaces (`tests/tunnel_netns.rs`, `run-netns-tunnel.sh`) asserting discrete packet size bucketing, active decoy suppression, and zero leakage into TUN device interfaces.
 - **Data-plane windowed loss calculation, 8-contender harness & UDP-under-loss evaluation (`bin/yipd`, `crates/yip-transport`, `crates/yip-bench`, #11).**
   Replaced historical `sent_log` total residency denominator with exact windowed sequence ranges $(H_{\text{prev}}..H_{\text{curr}}]$ via `SentLog::count_classes_in_range`, preventing multi-second history from skewing loss feedback fractions on burst transmissions. Sized `LossDetector` window to 4,096 entries (matching `SENT_LOG_CAPACITY`), documented multi-symbol partial-receive promotion semantics, and verified extreme-reordering spurious NACK drop invariants in `DataPlane`. Expanded comparative benchmark suite (`crates/yip-bench/tests/run-iperf-compare.sh`, `crates/yip-bench/setup-contenders.sh`) to evaluate 8 contenders (`yip`, `wireguard`, `amneziawg`, `openvpn`, `n2n`, `zerotier`, `tailscale`, `netbird`) across dual TCP goodput and UDP-under-loss (`iperf3 -u`) sweeps with graceful netns auto-detection, local air-gapped controller isolation, and a turnkey contender setup script. Parameterized benchmark runners (`run-compare.sh`, `run-iperf-compare.sh`, `run-wan-bench.sh`) for configurable `PING_COUNT` (supporting 1,000 pings at 5ms intervals with fractional percentage parsing to tighten netem variance to $\pm 0.1\%$).
 - **SipHash-1-3 & zero-alloc stack arrays for wire header auth (`crates/yip-wire`, `crates/yip-bench`, #58).**

README.md

@@ -117,13 +117,13 @@ All benchmark charts are generated deterministically from verified testbed data.
 <!-- BENCHMARK-TABLE-START -->
 
 <!-- generated by crates/yip-bench/wan/collect.sh -->
-*Two 1-vCPU Debian 13 VPSes, ~54.411 ms apart, 2026-10-22. yip trades raw clean-path throughput for loss resilience — see the FEC row.*
+*Two 1-vCPU Debian 13 VPSes, ~54.790 ms apart, 2026-10-22. yip trades raw clean-path throughput for loss resilience — see the FEC row.*
 
 | | TCP 1-stream | UDP loss (200M) | effective loss @10% injected |
 |---|--:|--:|--:|
-| **yip** | 258.5 Mbit/s | 0.00% | 0% |
-| **WireGuard** | 394.2 Mbit/s | 2.55% | 8% |
-| **OpenVPN** | 26.2 Mbit/s | 0.00% | 16% |
+| **yip** | 220.8 Mbit/s | 0.00% | 0% |
+| **WireGuard** | 421.9 Mbit/s | 0.00% | 14% |
+| **OpenVPN** | 25.8 Mbit/s | 0.15% | 7% |
 
 <!-- BENCHMARK-TABLE-END -->
 
@@ -167,7 +167,7 @@ Full reproduction instructions, test scripts, and historical logs are in [`crate
 | `yip-transport` | Systematic Reed–Solomon FEC (GF(256)), FEC object demuxing, per-flow classifier, thin ARQ. |
 | `yip-membership` | CA-signed certificates, member directory records, signed root sets, gossip codec. |
 | `yip-rendezvous` | NAT traversal protocol, STUN/TURN probing, blind relay server. |
-| `yip-obf` | Obfuscation envelope (SipHash-CTR keystream over a random nonce). |
+| `yip-obf` | Obfuscation envelope (SipHash-CTR keystream over a random nonce), DAITA discrete packet size bucketing, and cover traffic shaping primitives. |
 | `yip-utls` | Xray-REALITY TLS 1.3 mimicry primitives, Chrome JA3/JA4 fingerprint emulation. |
 | `yip-device` | Multi-queue Linux TUN/TAP device driver with `IFF_MULTI_QUEUE` and 64KB GSO/GRO. |
 | `yipd` | The daemon combining all subsystems into a unified mesh node. |
@@ -251,16 +251,16 @@ cp example.config my-node.config
 sudo target/release/yipd my-node.config
 ```
 
-For two-node tunnels, mesh setups, and NAT configuration, consult the [User Guide](docs/user-guide.md) and [Configuration Reference](docs/configuration.md).
+For two-node tunnels, mesh setups, NAT configuration, and DAITA traffic analysis defense (`traffic_defense = balanced`), consult the [User Guide](docs/user-guide.md) and [Configuration Reference](docs/configuration.md).
 
 ---
 
 ## Security Model
 
 - **Data Plane & Handshake**: Single-RTT post-quantum hybrid key exchange (`Noise_IKpsk2` + ML-KEM-512 / FIPS 203) with ChaCha20-Poly1305 AEAD data plane, per-direction keys, a WireGuard-style replay window, and ~120s ephemeral rekey with epoch overlap. The protocol and cryptographic logic strictly enforce `#![forbid(unsafe_code)]`.
 - **Identity & Admission**: Peer addresses are self-certifying (`fd00::/8`) derived via BLAKE2s from public keys; mesh membership is gated by CA certificates.
-- **Anti-DPI Verification**: Verified in CI against four independent DPI engines (**nDPI**, **Zeek**, **Suricata**, and **Wireshark**).
-- **What is *not* defended yet**: Traffic-analysis (timing/padding shape) defense is in development. Statistical packet-burst size classifiers can observe flow patterns without deep packet content inspection.
+- **Anti-DPI Verification & Traffic Defense**: Verified in CI against four independent DPI engines (**nDPI**, **Zeek**, **Suricata**, and **Wireshark**). When `traffic_defense` is enabled (`balanced` or `paranoid`), DAITA discrete packet size bucketing, stochastic multi-packet decoy bursts, and bounded egress micro-jitter queues eliminate packet size histograms, idle-to-active burst transitions, and inter-arrival time regularity.
+- **What is *not* defended yet**: Multi-hop anonymity / onion routing. `yip` is a direct peer-to-peer mesh; an adversary with global network vantage points can still correlate sender and receiver endpoints by aggregate flow volume over extended observation windows.
 
 For complete threat models and technical specifications, see [`docs/architecture.md`](docs/architecture.md).
 

ROADMAP.md

@@ -53,19 +53,20 @@ maintainer.
   and stack-allocated keystream generation (`header_mask`), slashing scalar MAC CPU by ~45% and eliminating
   intermediate heap allocations on data-plane framing.
 - **Data-plane windowed loss, 8-contender harness & bench polish (#11)** — exact per-class windowed loss fractions ($L_{\text{class}} = M_{\text{class}} / S_{\text{class}}$ in $(H_{\text{prev}}..H_{\text{curr}}]$), 4096-entry synchronized loss detection window matching sent-log capacity, bounded spurious NACK drop invariants, 8-contender comparison matrix and netns runners (yip, WireGuard, AmneziaWG, OpenVPN, n2n, ZeroTier, Tailscale, NetBird), dual TCP & UDP-under-loss evaluation, and configurable 1000-ping variance tightening.
+- **Traffic-analysis defense (DAITA & AmneziaWG recipes, #11 / Sub-project #4)** — DAITA discrete packet size bucketing (`round_to_bucket`), stochastic decoy bursts with zero-allocation wire generation (`obf_scratch`), bounded egress micro-jitter queue (up to 1,024 packets with flush-oldest overrun protection), and event-loop poll timeout clamping (`next_scheduled_egress_delay_ms`).
 
 ## Now
 
-- **Traffic-analysis defense (#11 / Sub-project #4)** — jittered cover traffic cadence, packet size shaping, and AmneziaWG junk/padding recipes.
+- **Multi-platform native drivers** — macOS (NetworkExtension / utun) and Windows (Wintun).
+- **Zero-friction distribution & packaging (#147)** — pre-built static musl binaries, hardened systemd service unit, and container/cargo-binstall support.
 
 ## Next
 
-- **Multi-platform native drivers** — macOS (NetworkExtension / utun) and Windows (Wintun).
-- **Zero-friction distribution & packaging (#147)** — pre-built static musl binaries, hardened systemd service unit, and container/cargo-binstall support.
+- **REALITY P256/P384 server-side KEX + HTTP/2 decoy (#84)** — broadening cipher suites and HTTP/2 decoy multiplexing.
 
 ## Later
 
-- **Multi-platform native drivers** — macOS (NetworkExtension / utun) and Windows (Wintun).
+- **Onion routing / multi-hop mixnet extensions** — multi-hop anonymity overlays.
 
 ## Not goals (for now)