Constant SERVER_HELLO_ECH_CONFIRMATION_SPAN

const SERVER_HELLO_ECH_CONFIRMATION_SPAN: Range<usize>;

The last eight bytes of the ServerHello’s random, taken from a Handshake message containing it.

This has:

• a HandshakeType (1 byte),
• an exterior length (3 bytes),
• the legacy_version (2 bytes), and
• the balance of the random field (24 bytes).