TLS-Attacker: A Dynamic Framework for Analyzing TLS Implementations

TLS-Attacker implements more than 330 cipher suites, including uncommon GOST and SM cipher suites specified by the Russian and Chinese authorities, covering SSL 3.0 through TLS 1.3 as well as DTLS 1.0 and DTLS 1.2. This breadth lets researchers test whether authority-mandated or jurisdiction-specific cipher suite selections alter TLS fingerprint classification by censors in those countries.

§2 Development evaluation tls-fingerprint cnru

The TLS-Attacker suite is being extended to cover QUIC and DTLS 1.3 under a universal analysis framework that reuses existing Workflow Trace and Modifiable Variable machinery with only protocol-specific components added. As of 2024 the QUIC dialect is functional, making TLS-Attacker the only open-source tool that can fuzz TLS, DTLS, and QUIC handshakes under a single scriptable API.

§2 Development / §3 Outlook evaluation tls-fingerprinthttp3-quic-block

TLS-Attacker's Workflow Traces and Modifiable Variables mechanisms allow testers to specify arbitrary protocol flows and apply field-level modifications — including adding, removing, or overwriting individual TLS message fields — without breaking the internal TLS state machine. This makes it the standard instrument for probing how DPI systems and active-probing detectors respond to non-standard or mutated TLS handshakes.

§1 Introduction evaluation tls-fingerprintactive-probingdpi

TLS-Scanner, a subproject of the TLS-Attacker suite, automates handshake probes across deployed TLS hosts and has been used in published IPv4-wide scanning studies. It surfaces supported protocol versions, enabled extensions, and known vulnerabilities, providing a ready-made audit tool for circumvention infrastructure operators.

§2 Impact (Academic Perspective) evaluation tls-fingerprintmeasurement-platform