- Introduced multiple adversarial tests for MTProto handshake to ensure robustness against replay attacks, invalid mutations, and concurrent flooding.
- Implemented a function to build proxy headers based on the specified version, improving the handling of masking protocols.
- Added tests to validate the behavior of the masking functionality under various conditions, including unknown proxy protocol versions and oversized payloads.
- Enhanced relay tests to ensure stability and performance under high load and half-close scenarios.
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 a new test module for middle relay idle policy security tests, covering various scenarios including soft mark, hard close, and grace periods.
- Implemented functions to create crypto readers and encrypt data for testing.
- Enhanced the Stats struct to include counters for relay idle soft marks, hard closes, pressure evictions, and protocol desync closes.
- Added corresponding increment and retrieval methods for the new stats fields.
- Implement a test to ensure that exceeding the user connection limit does not leak the current connections counter.
- Add tests for direct relay connection refusal and adversarial scenarios to verify proper error handling.
- Introduce fuzz testing for MTProto handshake to ensure robustness against malformed inputs and replay attacks.
- Remove obsolete short TLS probe throttle tests and integrate their functionality into existing security tests.
- Enhance middle relay tests to validate behavior during connection drops and cutovers, ensuring graceful error handling.
- Add a test for half-close scenarios in relay to confirm bidirectional data flow continues as expected.
- 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.
- Updated `direct_relay_security_tests.rs` to ensure sanitized paths are correctly validated against resolved paths.
- Added tests for symlink handling in `unknown_dc_log_path_revalidation` to prevent symlink target escape vulnerabilities.
- Modified `handshake.rs` to use a more robust hashing strategy for eviction offsets, improving the eviction logic in `auth_probe_record_failure_with_state`.
- Introduced new tests in `handshake_security_tests.rs` to validate eviction logic under various conditions, ensuring low fail streak entries are prioritized for eviction.
- Simplified `route_mode.rs` by removing unnecessary atomic mode tracking, streamlining the transition logic in `RouteRuntimeController`.
- Enhanced `route_mode_security_tests.rs` with comprehensive tests for mode transitions and their effects on session states, ensuring consistency under concurrent modifications.
- Cleaned up `emulator.rs` by removing unused ALPN extension handling, improving code clarity and maintainability.
- 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.
- Introduced `copy_with_idle_timeout` function to handle reading and writing with an idle timeout.
- Updated the proxy masking logic to use the new idle timeout function.
- Added tests to verify that idle relays are closed by the idle timeout before the global relay timeout.
- Ensured that connect refusal paths respect the masking budget and that responses followed by silence are cut off by the idle timeout.
- Added tests for adversarial scenarios where clients may attempt to drip-feed data beyond the idle timeout.
- 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.
- Introduced `BOOT_TIME_MAX_SECS` constant to define the maximum accepted boot-time timestamp.
- Updated `validate_tls_handshake_at_time` to utilize the new boot time constant for timestamp validation.
- Enhanced `extract_sni_from_client_hello` to validate SNI hostnames against specified criteria, rejecting invalid hostnames.
- Added tests to ensure proper handling of boot time timestamps and SNI validation.
feat(handshake): improve user secret decoding and ALPN enforcement
- Refactored user secret decoding to provide better error handling and logging for invalid secrets.
- Added tests for concurrent identical handshakes to ensure replay protection works as expected.
- Implemented ALPN enforcement in handshake processing, rejecting unsupported protocols and allowing valid ones.
fix(masking): implement timeout handling for masking operations
- Added timeout handling for writing proxy headers and consuming client data in masking.
- Adjusted timeout durations for testing to ensure faster feedback during unit tests.
- Introduced tests to verify behavior when masking is disabled and when proxy header writes exceed the timeout.
test(masking): add tests for slowloris connections and proxy header timeouts
- Created tests to validate that slowloris connections are closed by consume timeout when masking is disabled.
- Added a test for proxy header write timeout to ensure it returns false when the write operation does not complete.
- 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
- Per-user ad_tag in [access.user_ad_tags], global fallback in general.ad_tag
- User tag overrides global; if no user tag, general.ad_tag is used
- Both general.ad_tag and user_ad_tags support hot-reload (no restart)
