[TLS] Connection ID in TLS

[John Mattsson <[e-mail]>]

I think Connection ID is an important enabler for end-to-end security with (D)TLS. There seems to be important use cases for connection ID in TLS as well, see https://www.ietf.org/mailman/listinfo/atlas. At the Monday afternoon TLS session, it was stated that Connection ID in TLS was unemployable in the wild due to middleboxes. Couldn't that be solved by placing the cid field after the length field? E.g.

   struct {
      ContentType opaque_type = application_data; /* 23 */
      ProtocolVersion legacy_record_version = 0x0303; /* TLS v1.2 */
      uint16 length;
      opaque cid[cid_length];               // New field
      opaque encrypted_record[TLSCiphertext.length];
   } TLSCiphertext;

   length  The sum of cid_length and TLSCiphertext.length

(Also draft-ietf-tls-dtls-connection-id-00 says obsoletes RFC6347, should be updates).

Cheers,
John