A November 2024 commit to the stellar DPI engine's TLS decoder adds JA4 and JA4S TLS-handshake fingerprint calculation ("tls decoder support calculating JA4/JA4S fingerprint"), showing Geedge's core inspection engine has adopted the modern JA4/JA4S fingerprinting scheme (successor to JA3/JA3S) for client/server TLS fingerprinting as of late 2024.
d7f8f42327ccbdd5fcc3c7f056869448cfbafd80|liuxueli|[email protected]|2024-11-01|tls decoder support calculating JA4/JA4S fingerprint
Defense implications
- Any TLS-mimicking transport (e.g. REALITY, Trojan) should be validated against JA4/JA4S fingerprint uniformity with genuine client populations, not just JA3 — JA4 changes cipher-suite/extension ordering handling and adds ALPN/SNI-presence signals that older JA3-focused evasion work may not account for.
Cited artifacts
mesalab_git—stellar/stellar.bundle(git-commit-log)
Provenance pointers only — no leak content is rehosted. Raw material: Enlace Hacktivista.
Related findings
Two IIE graduate-research repos (cuiyiming/gradproj, a 2019-2020 master's thesis project citing NDSS'17 TLS-interception-measurement and TLS-client-identification papers; daxiaoxu/xmr_bsexpr2, a 2022 project with GRU-based sequence classifiers over TCP/DNS flow JSON and deleted docs on TLS1.3 and Tencent's proprietary MMTLS protocol) document the ML feature-engineering methodology (TLS certificate length, handshake message sequences, JA3-style statistics, Markov-chain packet-size/timing models, GRU sequence models) that plausibly underlies production classifiers (e.g. stellar's later JA4/JA4S support, MESA_sts's randomness checks).
A June 2024 MESA Lab internal survey ("针对审查系统的科学研究及探测技术调研报告") explicitly states its purpose is to catalog academic/public censorship-measurement and circumvention research (OONI, Augur, Satellite, GFWatch, Citizen Lab, CensorBib, FOCI/IMC/NDSS/CCS/USENIX Security papers) in order to find and patch GFW/censorship-system vulnerabilities before outside researchers exploit them. It systematically covers circumvention protocols/tools (Shadowsocks, VMess, Trojan, decoy routing, Parrot-style mimicry, CovertCast, Slitheen++, ESNI/ECH, uTLS) and notes GFW blocked ESNI (not ECH) since July 2020, plus historical TLS-fingerprint blocking of meek by a Cyberoam firewall (2016).
A MESA research-log entry details a NAT/shared-connection identification methodology combining TCP/IP fingerprinting (IP-ID, TTL, DF, window size, MSS, TCP-option ordering -- p0f-style), HTTP User-Agent diversity, TLS/SSL JA3 fingerprint diversity, and traffic statistical features (concurrent-TCP-connection count, idle-time jitter, upstream/downstream ratio stability, DNS query frequency) per endpoint over rolling time windows, with detection methods spanning direct UA inspection, threshold statistics, ML classifiers (random forest/SVM), and per-window entropy jumps across the fingerprint features.
Geedge extracted and analyzed Betternet VPN's underlying protocols (WireGuard, a proprietary "Hydra" protocol using spoofed-domain TLS 1.2, and IKEv2), and found the Hydra protocol could be "completely blocked" via JA3 TLS fingerprinting; IKEv2 was blocked via UDP port 500/4500 policy, and thousands of VPN server IPs were extracted as a supplementary IP blocklist.
A MESA Lab repo (daxiaoxu/xmr_bsexpr3) contains standalone detection/fingerprinting scripts specifically targeting QQ (Mobile and Windows clients) and WeChat, alongside a script named PSK_LifeTime.py, suggesting TLS session-resumption / PSK-ticket lifetime is being explored as a traffic-fingerprinting feature for identifying or tracking these apps' encrypted sessions.
Internal spec for "spacemap-service", a passive-DPI-fed reconnaissance database and web UI that catalogs every observed website's IP/domain, geolocation, ASN, DNS server, CDN vendor, TLS certificate fields (issuer/CN/SNI), OS and web-framework fingerprint (via Wappalyzer), and WHOIS/ICP registration data, exposing reverse-lookup search by any single attribute (e.g. all sites behind a given cert issuer, ASN, or CDN vendor).