hashed := sha512.Sum512(b[:])
	// The first 16 bytes of the hash used to be exposed on the wire as a ticket
	// prefix. They MUST NOT be used as a secret. In the future, it would make
	// sense to use a proper KDF here, like HKDF with a fixed salt.
	const legacyTicketKeyNameLen = 16
	copy(key.aesKey[:], hashed[legacyTicketKeyNameLen:])
	copy(key.hmacKey[:], hashed[legacyTicketKeyNameLen+len(key.aesKey):])

}

type transcriptHash interface {
	Write([]byte) (int, error)
}

// transcriptMsg is a helper used to hash messages which are not hashed when
// they are read from, or written to, the wire. This is typically the case for
// messages which are either not sent, or need to be hashed out of order from
// when they are read/written.
//
// For most messages, the message is marshalled using their marshal method,

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.

	"handSize":         "`handSize` is a small positive number that configures the shuffle sharding of requests into queues.  When enqueuing a request at this priority level the request's flow identifier (a string pair) is hashed and the hash value is used to shuffle the list of queues and deal a hand of the size specified here.  The request is put into one of the shortest queues in that hand. `handSize` must be no larger than `queues`, and should be significantly smaller (so that...

  // `handSize` is a small positive number that configures the
  // shuffle sharding of requests into queues.  When enqueuing a request
  // at this priority level the request's flow identifier (a string
  // pair) is hashed and the hash value is used to shuffle the list
  // of queues and deal a hand of the size specified here.  The
  // request is put into one of the shortest queues in that hand.