nx_tls13_schedule_test.nx

nx_tls13_schedule_test.nx -- RFC 8448 §3 cascade KAT for TLS 1.3 key schedule. RFC 8448 §3 "Simple 1-RTT Handshake" worked example. We don't compute X25519 here (that's nx_x25519's own KAT); we feed in the ECDHE shared secret as a known input and verify every cascade secret downstream matches the spec byte-exact. Inputs: PSK = 0^32 (no-PSK case) ECDHE.shared= 8bd4054fb55b9d63fdfbacf9f04b9f0d35e6d63f537563efd46272900f89492d empty_hash = SHA-256("") = e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 Expected cascade: early_secret = 33ad0a1c607ec03b09e6cd9893680ce210adf300aa1f2660e1b22e10f170f92a derived_1 = 6f2615a108c702c5678f54fc9dbab69716c076189c48250cebeac3576c3611ba handshake_secret = 1dc826e93606aa6fdc0aadc12f741b01046aa6b99f691ed221a9f0ca043fbeac derived_2 = 43de77e0c77713859a944db9db2590b53190a65b3ee2e4f12dd7a0bb7ce254b4 master_secret = 18df06843d13a08bf2a449844c5f8a478001bc4d4c627984d5a41da8d0402919 Plus per-traffic-secret AEAD key + IV derivation succeeds and produces the expected lengths (32-byte key, 12-byte IV for ChaCha20-Poly1305). expect_exit: 0 license_tier: ORIGINAL