1. Introduction

This section preserves the RFC text for BUSA-TLS, including TLS 1.3 HKDF key schedule changes, Mandatory Audio Component, MAC derivation, alert handling, implementation notes, security considerations, and IANA considerations.

Original RFC Text

1.  Introduction

   TLS 1.3 was designed, in part, to eliminate the class of negotiated-
   null vulnerabilities that plagued earlier versions of the protocol.
   [RFC8446] achieves this through a combination of mandatory
   authenticated encryption, removal of the ChangeCipherSpec handshake
   message's semantic content, and the elimination of all null cipher
   suite identifiers.

   The TLS 1.3 key schedule begins, in the PSK-free case, with the
   following operation derived using the HMAC-based Key Derivation
   Function (HKDF) [RFC5869]:

     Early Secret = HKDF-Extract(salt=0x00...00, IKM=0x00...00)

   Zeros.  The most successfully de-nulled protocol in common use opens
   its key derivation with nothing.

   This specification addresses this aesthetic problem by replacing the
   zero-byte IKM with a cryptographically derived value taken from a
   specific audio recording that was itself subject to institutional
   attempts at nullification.

   The choice of "Banned in the U.S.A." [BUSA] is not arbitrary.  It is
   load-bearing.