geedge.lantern.io
detection confidence: medium public

In the same live TSG capture, rows show ssl_ech_flag=1 recorded for real observed TLS sessions (to connect-api.guardianapp.com) alongside a populated ssl_ja3_hash and an intact ssl_sni value, and the session was still denied by name-based rule Deny_Brave. This confirms the DPI engine parses and logs the TLS ClientHello ECH extension as a distinct per-session flag in production/test traffic, i.e. ECH usage is visible to the gateway even though SNI in this particular capture was not itself encrypted from the classifier's point of view.

server_fqdn: connect-api.guardianapp.com, ssl_esni_flag: 0, ssl_ech_flag: 1, ssl_ja3_hash: ebed71c4037aa7e54c1056c9968cf72a

Defense implications

productstsg
capabilitydpi-signature

extracted_by: claude-sonnet-5 · added 2026-08-26 · id: 2026-ae-tsg-ech-live-detect

Related findings

detection

Two independently-leaked TSG session-log CSV exports share an identical 224-field schema whose proxy_* columns (proxy_action, proxy_pinning_status, proxy_intercept_status, proxy_cert_verify, proxy_intercept_error) log the outcome of TLS interception per session, alongside ssl_ja3_hash/ssl_ja3s_hash, ssl_esni_flag, ssl_ech_flag, and quic_sni fields — confirming MITM/cert-pinning-bypass instrumentation and TLS/QUIC fingerprinting are built into TSG's standard traffic-logging pipeline, not a bolt-on feature.

deployment

An internal TSG operations/troubleshooting manual lays out TSG's full traffic pipeline (NIC -> mrzcpd/marsio capture driver -> sapp DPI engine -> firewall/proxy(KNI->TFE)/active-defense/WAN-NAT policy branches) and shows engineers using maat_redis_tool to pull the live Redis-synced blocking policy tables (TSG_SECURITY_COMPILE, TSG_OBJ_IP_ADDR, TSG_OBJ_APP_ID) and filter them by numeric policy/object ID to debug why a block rule isn't firing.

detection

The internal 'MAAT网络流处理配置统一描述框架' engineering manual (v3.1.20, author 郑超, 2021) documents MAAT's Redis-synced rule-compilation framework and its RuleScan/Hyperscan-based pattern-matching engine (libmaatframe.so / librulescan), and records that RuleScan's fast-scan feature caused a production outage on 2019-03-19 and has been disabled ever since.

detection

An internal TSG functional-requirements spec ('加密协议JG') defines device support for identifying and blocking ECH, ESNI and QUIC traffic via per-connection SNI/region-matching tables (e.g. DF_QUIC_REGION), plus a companion 'FD报文全流程感知' feature that both passively monitors and actively injects synthetic verification traffic end-to-end through the network path to compute a live per-rule 'CT率' (breakthrough/penetration rate) — the system self-measures how often its own QUIC/ESNI/ECH blocks fail to take effect, and separately throttles logging/blocking detail for rule IDs receiving unusually high hit counts (DF_ATTACK_PROTECTION, 'targeted attack detection').

detection

An internal SQL query cookbook targets a ClickHouse-style database 'tsg_galaxy_v3.session_record' with example top-10 breakdowns by common_l4_protocol, common_client_ip, common_server_ip, common_app_id, common_app_label, http_domain, and — notably — common_subscriber_id, plus filtered variants (e.g. by http_domain LIKE '%baidu.com%' or by a specific client IP) using a 1-in-10 sampling trick (cityHash64(common_recv_time) % 10 = 0). This names the internal analytics database and confirms subscriber-level session records are a standard, first-class query dimension, not an edge case.

detection

Raw TSG session_record CSV exports (header row `recv_time,log_id,decoded_as,session_id,...`) show a ~224-column per-session logging schema that goes far beyond blocking metadata: subscriber_id/imei/imsi/apn/phone_number identity fields, full DNS query/response, HTTP with a cleartext mail_password field for mail protocols, TLS JA3/JA3S hashes, cert issuer/subject, ESNI/ECH flags, SIP/RTP VoIP metadata, SSH hassh fingerprints, RDP client details, and cryptocurrency-mining (stratum) protocol detection. This is a general-purpose deep-inspection/logging pipeline, not a narrow blocklist filter.