A 2020 MESA Lab monthly report describes building an encrypted-DNS gateway device and a self-hosted DoH server that was wired directly into a live "TSG platform WAN net interface", alongside a passive DoH-service-discovery pipeline that found 39 new DoH-serving domains in a single day of backbone ("科技网") traffic; a related note documents actively probing known DoH-serving IPs' upstream resolvers via a proxy network across 196 countries to check which still function.
DoH服务器串联TSG平台wan net接口... 完善DoH服务器bind部分配置,增加日志、权威等部分
Defense implications
- Encrypted-DNS (DoH) resolvers and their serving domains are both actively cataloged (via multi-country active probing) and passively discovered (from live backbone traffic, within about a day of exposure) by this lab -- a Lantern deployment relying on a lesser-known or self-hosted DoH resolver should assume discoverability on this timescale, not safety through obscurity.
Related findings
Geedge fingerprinted several V2Ray-based VPN apps by their fixed API/bootstrap domains rather than protocol characteristics — blocking "V2 Pro" via pro.mucacherry.org, "V2 VPN" via v2.mucacherry.org, and "V2Net VPN" via api.v2net.live plus 5 rotating free-node domains (free1-5.v2n3t2.online / v2n3t.online) the app uses to fetch node lists.
PanGu defines a configurable DNS response-spoofing subsystem (NTC_DNS_FAKE_IP_CB, NTC_DNS_RES_STRATEGY) supporting named 'answer groups' with a configurable number of fake answers returned per group (service ID 0x40 'dns欺骗'), i.e. DNS injection is a general, group-configurable policy primitive in TSG rather than a single hardcoded fake-IP response.
relationship-gtpc-user derives a single per-subscriber correlation key as Hashkey = md5(IMEI + IMSI + phone_number + vsys_id) from mobile-core GTP-C signaling, and a separate per-tunnel key gtp_uuid = md5(uplink_teid + "|" + downlink_teid). On every update it writes not just the primary user<->TEID row (tsg_galaxy:relation_user_teid) but up to four additional secondary-index rows into tsg_galaxy:gtpc_knowledge_base, one per identifier (IMEI, IMSI, phone number, APN) with a type-digit prefix ("0"/"1"/"2"/"3") and — for phone number and APN — the value's characters reversed before use as the row key, a range-scan-friendly key design that lets any of the four identifiers be used to look up the associated tunnel/session independently.
log-subscriber-hbase-datacenter is a Storm topology that, on a 300-second tick, scans a "national center" HBase cluster (national.hbase.zookeeper.servers) for subscriber_id/account rows changed in that window and replicates them into a separate "branch/regional datacenter" HBase cluster (center.hbase.zookeeper.servers, table sub:subscriber_info) — confirming a two-tier, hub-and-spoke data-federation architecture where subscriber-account correlation data is centrally maintained at a national level and periodically pushed down to per-datacenter local copies for regional/site-level querying.
radius-relationship-hbase (galaxy/tsg_olap) builds a bidirectional, MD5-keyed RADIUS accounting index in HBase — a framed-IP-to-account table and its account-to-IP mirror — so any subscriber account or assigned IP can be looked up in O(1) from either direction, per multi-tenant vsys_id. Each direction is fronted by a Guava write-through cache (10M-entry cap, 24h TTL) so lookups do not hit HBase on the hot path.
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').