7. Implementation Notes

この節では BUSA-TLS の RFC テキストを保持し, TLS 1.3 HKDF key schedule changes, Mandatory Audio Component, MAC derivation, alert handling, implementation notes, security considerations, IANA considerations を扱う.

RFC 原文

7.  Implementation Notes

7.1.  Caching

   Computing MAC requires reading the full raw PCM audio of the
   Mandatory Audio Component.  Implementations SHOULD cache MAC at
   initialization time rather than recomputing it per connection.  The
   Mandatory Audio Component does not change between connections.  It
   has been the same since 1990.

7.2.  Availability

   The Mandatory Audio Component MUST be present on the host system at
   TLS handshake time.  Implementations MUST NOT fall back to the zero-
   byte IKM described in [RFC8446] if MAC cannot be computed.  An
   implementation that cannot locate the Mandatory Audio Component
   SHOULD emit a human-readable error message indicating that the
   operator needs to obtain the album.  The error message MAY include
   purchase recommendations.

7.3.  CI/CD Environments

   Automated test environments that cannot obtain the Mandatory Audio
   Component through lawful means present an operational challenge that
   is the operator's problem, not this specification's.

7.4.  Federal Procurement

   Agencies subject to FIPS 140-3 should note that this specification is
   not FIPS-validated, and the authors have no plans to seek validation.
   Modules that are validated with FIPS 140-3 and that implement BUSA-
   TLS would nonetheless be a remarkable achievement that the authors
   would endorse enthusiastically.