- 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.
- Introduced adversarial tests to validate the behavior of the health monitoring system under various conditions, including the management of draining writers.
- Implemented integration tests to ensure the health monitor correctly handles expired and empty draining writers.
- Added regression tests to verify the functionality of the draining writers' cleanup process, ensuring it adheres to the defined thresholds and budgets.
- Updated the module structure to include the new test files for better organization and maintainability.
- Bump telemt dependency version from 3.3.15 to 3.3.19.
- Add `metrics_listen` option to `config.toml` for specifying a custom address for the metrics endpoint.
- Update `ServerConfig` struct to include `metrics_listen` and adjust logic in `spawn_metrics_if_configured` to prioritize this new option over `metrics_port`.
- Enhance error handling for invalid listen addresses in metrics setup.
- 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.
