nx_tls12_hello.nx

nx_tls12_hello.nx -- TLS 1.2 ClientHello emitter (rung 1 of the sovereign TLS 1.2 client). ROOT CAUSE (probed 2026-06-23, news.ycombinator.com): some endpoints are TLS 1.2-ONLY and reject our 1.3-only ClientHello with a fatal protocol_version(70) alert; after we offered 1.2 they want a 1.2 cipher we didn't send. This module emits a real 1.2 ClientHello so we can negotiate 1.2 with those servers -- the "access everywhere" unlock (the crypto primitives + nx_tls12_prf already exist; this wires the protocol). Offered cipher suites = the ones we can actually COMPLETE (AEAD + SHA256 PRF = nx_tls12_prf_sha256): 0xC02B ECDHE-ECDSA-AES128-GCM-SHA256 0xC02F ECDHE-RSA-AES128-GCM-SHA256 0xCCA9 ECDHE-ECDSA-CHACHA20-POLY1305-SHA256 0xCCA8 ECDHE-RSA-CHACHA20-POLY1305-SHA256 (AES-256-GCM-SHA384 omitted: needs the P_SHA384 PRF/key-schedule, a later rung.) Extensions reuse the version-agnostic emitters from nx_tls13_ext.nx (server_name, supported_groups, signature_algorithms) + a 1.2-needed ec_point_formats. license_tier: ORIGINAL