Add `rst_on_close` config option (off/errors/always) to control
SO_LINGER(0) behaviour on accepted TCP connections.
- `off` (default): normal FIN on all closes, no behaviour change.
- `errors`: SO_LINGER(0) set on accept, cleared after successful
handshake auth. Pre-handshake failures (scanners, DPI probes,
timeouts) send RST instead of FIN, eliminating FIN-WAIT-1 and
orphan socket accumulation. Authenticated relay sessions still
close gracefully with FIN.
- `always`: SO_LINGER(0) on accept, never cleared — all closes
send RST regardless of handshake outcome.
This commit introduces a comprehensive set of improvements to enhance
the security, reliability, and configurability of the proxy server,
specifically targeting adversarial resilience and high-load concurrency.
Security & Cryptography:
- Zeroize MTProto cryptographic key material (`dec_key`, `enc_key`)
immediately after use to prevent memory leakage on early returns.
- Move TLS handshake replay tracking after full policy/ALPN validation
to prevent cache poisoning by unauthenticated probes.
- Add `proxy_protocol_trusted_cidrs` configuration to restrict PROXY
protocol headers to trusted networks, rejecting spoofed IPs.
Adversarial Resilience & DoS Mitigation:
- Implement "Tiny Frame Debt" tracking in the middle-relay to prevent
CPU exhaustion from malicious 0-byte or 1-byte frame floods.
- Add `mask_relay_max_bytes` to strictly bound unauthenticated fallback
connections, preventing the proxy from being abused as an open relay.
- Add a 5ms prefetch window (`mask_classifier_prefetch_timeout_ms`) to
correctly assemble and classify fragmented HTTP/1.1 and HTTP/2 probes
(e.g., `PRI * HTTP/2.0`) before routing them to masking heuristics.
- Prevent recursive masking loops (FD exhaustion) by verifying the mask
target is not the proxy's own listener via local interface enumeration.
Concurrency & Reliability:
- Eliminate executor waker storms during quota lock contention by replacing
the spin-waker task with inline `Sleep` and exponential backoff.
- Roll back user quota reservations (`rollback_me2c_quota_reservation`)
if a network write fails, preventing Head-of-Line (HoL) blocking from
permanently burning data quotas.
- Recover gracefully from idle-registry `Mutex` poisoning instead of
panicking, ensuring isolated thread failures do not break the proxy.
- Fix `auth_probe_scan_start_offset` modulo logic to ensure bounds safety.
Testing:
- Add extensive adversarial, timing, fuzzing, and invariant test suites
for both the client and handshake modules.
- Introduced `handshake_real_bug_stress_tests.rs` to validate TLS and MTProto handshake behaviors under various conditions, including ALPN rejection and session ID handling.
- Implemented tests to ensure replay cache integrity and proper handling of malicious input without panicking.
- Added `handshake_timing_manual_bench_tests.rs` for performance benchmarking of user authentication paths, comparing preferred user handling against full user scans in both MTProto and TLS contexts.
- Included timing-sensitive tests to measure the impact of SNI on handshake performance.
- Introduced client TLS record wrapping tests to ensure correct handling of empty and oversized payloads.
- Added integration tests for middle relay to validate quota saturation behavior under concurrent pressure.
- Implemented high-risk security tests covering various payload scenarios, including alignment checks and boundary conditions.
- Developed length cast hardening tests to verify proper handling of wire lengths and overflow conditions.
- Created quota overflow lock tests to ensure stable behavior under saturation and reclaim scenarios.
- Refactored existing middle relay security tests for improved clarity and consistency in lock handling.
- Bump versions of several dependencies in Cargo.toml for improved functionality and security, including:
- socket2 to 0.6
- nix to 0.31
- toml to 1.0
- x509-parser to 0.18
- dashmap to 6.1
- rand to 0.10
- reqwest to 0.13
- notify to 8.2
- ipnetwork to 0.21
- webpki-roots to 1.0
- criterion to 0.8
- Introduce `OnceLock` for secure random number generation in multiple modules to ensure thread safety and reduce overhead.
- Refactor random number generation calls to use the new `RngExt` trait methods for consistency and clarity.
- Add new PNG files for architectural documentation.
- Introduced regression tests for relay quota wake liveness to ensure proper handling of contention and wake events.
- Added adversarial tests to validate the behavior of the quota system under stress and contention scenarios.
- Implemented security tests for the TLS stream to verify the preservation of pending plaintext during state transitions.
- Enhanced the pool writer tests to ensure proper quarantine behavior and validate the removal of writers from the registry.
- Included fuzz testing to assess the robustness of the quota and TLS handling mechanisms against unexpected inputs and states.
- Introduced `relay_quota_boundary_blackhat_tests.rs` to validate behavior under quota limits, including edge cases and adversarial conditions.
- Added `relay_quota_model_adversarial_tests.rs` to ensure quota management maintains integrity during bidirectional communication and various load scenarios.
- Created `relay_quota_overflow_regression_tests.rs` to address overflow issues and ensure that quota limits are respected during aggressive data transmission.
- Implemented `route_mode_coherence_adversarial_tests.rs` to verify the consistency of route mode transitions and timestamp management across different relay modes.
- Introduced red-team expected-fail tests for client masking shape hardening.
- Added integration tests for masking AB envelope blur to improve obfuscation.
- Implemented masking security tests to validate the behavior of masking under various conditions.
- Created tests for masking shape above-cap blur to ensure proper functionality.
- Developed adversarial tests for masking shape hardening to evaluate robustness against attacks.
- Added timing normalization security tests to assess the effectiveness of timing obfuscation.
- Implemented red-team expected-fail tests for timing side-channel vulnerabilities.
- Removed assertions for expected client hello messages in multiple TLS fallback tests to streamline the test logic.
- Updated the tests to focus on verifying the trailing TLS records received after the fallback.
- Enhanced the masking functionality by adding shape hardening features, including dynamic padding based on sent data size.
- Modified the relay_to_mask function to accommodate new parameters for shape hardening.
- Updated masking security tests to reflect changes in the relay_to_mask function signature.
- Rename MAX_TLS_RECORD_SIZE to MAX_TLS_PLAINTEXT_SIZE for clarity.
- Rename MAX_TLS_CHUNK_SIZE to MAX_TLS_CIPHERTEXT_SIZE to reflect its purpose.
- Deprecate old constants in favor of new ones.
- Update various parts of the codebase to use the new constants, including validation checks and tests.
- Add new tests to ensure compliance with RFC 8446 regarding TLS record sizes.
- Refactor existing tests to improve clarity and specificity in naming.
- Introduce new tests for minimum and maximum TLS ClientHello sizes, ensuring proper masking behavior for malformed probes.
- Implement differential timing tests to compare latency between malformed TLS and plain web requests, ensuring similar performance characteristics.
- Add adversarial tests for truncated TLS ClientHello probes, verifying that even malformed traffic is masked as legitimate responses.
- Enhance the overall test suite for robustness against probing attacks, focusing on edge cases and potential vulnerabilities in TLS handling.
This commit introduces the `into_inner_with_pending_plaintext` method to the `FakeTlsReader` struct. This method allows users to extract the underlying reader along with any pending plaintext data that may have been buffered during the TLS reading process. The method handles the state transition and ensures that any buffered data is returned as a vector, facilitating easier management of plaintext data in TLS streams.
Исправлена критическая логическая ошибка в цепочке Fake TLS -> MTProto.
Ранее при валидном TLS-хендшейке, но неверном MTProto-пакете, прокси
ошибочно передавал в маскирующий релей обернутый (FakeTls) поток.
Теперь транспорт корректно разворачивается (unwrap) до сырого сокета
через .into_inner(), обеспечивая полную прозрачность (wire-transparency)
для DPI и маскирующего бэкенда.
Security & Hardening:
- Логика приведена в соответствие с требованиями OWASP ASVS L2 (V5: Validation, Sanitization and Encoding).
- Реализовано поведение "fail-closed": при любой ошибке верификации прокси мимикрирует под обычный веб-сервер, не раскрывая своей роли.
- Улучшена диагностика и логирование состояний аутентификации для защиты от активного пробинга.
Adversarial Testing (Black-hat mindset):
- Добавлен отдельный пакет `client_tls_mtproto_fallback_security_tests.rs` (18+ тестов).
- Покрыты сценарии: хаос-фрагментация (побайтовая нарезка TLS-записей), record-splitting,
half-close состояния, сбросы бэкенда и replay-pressure.
- В `client_adversarial_tests.rs` добавлено 10+ тестов на "злые" гонки (race conditions),
утечки лимитов по IP и проверку изоляции состояний параллельных сессий.
- Все 832 теста проходят (passed) в locked-режиме.
- Introduced `client_adversarial_tests.rs` to stress test connection limits and IP tracker race conditions.
- Added `handshake_adversarial_tests.rs` for mutational bit-flipping tests and timing neutrality checks.
- Created `masking_adversarial_tests.rs` to validate probing indistinguishability and SSRF prevention.
- Implemented `relay_adversarial_tests.rs` to ensure HOL blocking prevention and data quota enforcement.
- Updated respective modules to include new test paths.
- Adjusted QUOTA_USER_LOCKS_MAX based on test and non-test configurations to improve flexibility.
- Implemented logic to retain existing locks when the maximum quota is reached, ensuring efficient memory usage.
- Added comprehensive tests for quota user lock functionality, including cache reuse, saturation behavior, and race conditions.
- Enhanced StatsIo struct to manage wake scheduling for read and write operations, preventing unnecessary self-wakes.
- Introduced separate replay checker domains for handshake and TLS to ensure isolation and prevent cross-pollution of keys.
- Added security tests for replay checker to validate domain separation and window clamping behavior.
- Modified `build_emulated_server_hello` to accept ALPN (Application-Layer Protocol Negotiation) as an optional parameter, allowing for the embedding of ALPN markers in the application data payload.
- Implemented logic to handle oversized ALPN values and ensure they do not interfere with the application data payload.
- Added new security tests in `emulator_security_tests.rs` to validate the behavior of the ALPN embedding, including scenarios for oversized ALPN and preference for certificate payloads over ALPN markers.
- Introduced `send_adversarial_tests.rs` to cover edge cases and potential issues in the middle proxy's send functionality, ensuring robustness against various failure modes.
- Updated `middle_proxy` module to include new test modules and ensure proper handling of writer commands during data transmission.
- Simplified eviction candidate selection in `auth_probe_record_failure_with_state` by tracking the oldest candidate directly.
- Enhanced the handling of stale entries to ensure newcomers are tracked even under capacity constraints.
- Added tests to verify behavior under stress conditions and ensure newcomers are correctly managed.
- Updated `decode_user_secrets` to prioritize preferred users based on SNI hints.
- Introduced new tests for TLS SNI handling and replay protection mechanisms.
- Improved deduplication hash stability and collision resistance in middle relay logic.
- Refined cutover handling in route mode to ensure consistent error messaging and session management.
- Implemented a mechanism to log unknown datacenter indices with a distinct limit to avoid excessive logging.
- Introduced tests to ensure that logging is deduplicated per datacenter index and respects the distinct limit.
- Updated the fallback logic for datacenter resolution to prevent panics when only a single datacenter is available.
feat(proxy): add authentication probe throttling
- Added a pre-authentication probe throttling mechanism to limit the rate of invalid TLS and MTProto handshake attempts.
- Introduced a backoff strategy for repeated failures and ensured that successful handshakes reset the failure count.
- Implemented tests to validate the behavior of the authentication probe under various conditions.
fix(proxy): ensure proper flushing of masked writes
- Added a flush operation after writing initial data to the mask writer to ensure data integrity.
refactor(proxy): optimize desynchronization deduplication
- Replaced the Mutex-based deduplication structure with a DashMap for improved concurrency and performance.
- Implemented a bounded cache for deduplication to limit memory usage and prevent stale entries from persisting.
test(proxy): enhance security tests for middle relay and handshake
- Added comprehensive tests for the middle relay and handshake processes, including scenarios for deduplication and authentication probe behavior.
- Ensured that the tests cover edge cases and validate the expected behavior of the system under load.
- Enforce TLS record length constraints in client handling to comply with RFC 8446, rejecting records outside the range of 512 to 16,384 bytes.
- Update security tests to validate behavior for oversized and undersized TLS records, ensuring they are correctly masked or rejected.
- Introduce new tests to verify the handling of TLS records in both generic and client handler pipelines.
- Refactor handshake logic to enforce mode restrictions based on transport type, preventing misuse of secure tags.
- Add tests for nonce generation and encryption consistency, ensuring correct behavior for different configurations.
- Improve masking tests to ensure proper logging and detection of client types, including SSH and unknown probes.
- forward valid-TLS/invalid-MTProto clients to mask backend in both client paths\n- harden TLS validation against timing and clock edge cases\n- move replay tracking behind successful authentication to avoid cache pollution\n- tighten secret decoding and key-material handling paths\n- add dedicated security test modules for tls/client/handshake/masking\n- include production-path regression for ClientHandler fallback behavior
Previously handle_bad_client used stream.local_addr() (the ephemeral
socket to the mask backend) as the dst in the outgoing PROXY protocol
header. This is wrong: the dst should be the address telemt is listening
on, or the dst from the incoming PROXY protocol header if one was present.
- handle_bad_client now receives local_addr from the caller
- handle_client_stream resolves local_addr from PROXY protocol info.dst_addr
or falls back to a synthetic address based on config.server.port
- RunningClientHandler.do_handshake resolves local_addr from stream.local_addr()
overridden by PROXY protocol info.dst_addr when present, and passes it
down to handle_tls_client / handle_direct_client
- masking.rs uses the caller-supplied local_addr directly, eliminating the
stream.local_addr() call
Adds mask_proxy_protocol config option (0 = off, 1 = v1 text, 2 = v2 binary)
that sends a PROXY protocol header when connecting to mask_host. This lets
the backend see the real client IP address.
Particularly useful when the masking site (nginx/HAProxy) runs on the same
host as telemt and listens on a local port — without this, the backend loses
the original client IP entirely.
PROXY protocol header is also sent during TLS emulation fetches so that
backends with proxy_protocol required don't reject the connection.
- Remove unused imports across multiple modules
- Add #![allow(dead_code)] for public API items preserved for future use
- Add #![allow(deprecated)] for rand::Rng::gen_range usage
- Add #![allow(unused_assignments)] in main.rs
- Add #![allow(unreachable_code)] in network/stun.rs
- Prefix unused variables with underscore (_ip_tracker, _prefer_ipv6)
- Fix unused_must_use warning in tls_front/cache.rs
This ensures clean compilation without warnings while preserving
public API items that may be used in the future.
