architecture/format/README.md

D4 encapsulation protocol version 1 (DRAFT)

Headers

Name	bit size	Description
version	uint 8	Version of the header
type	uint 8	Data encapsulated type
uuid	uint 128	Sensor UUID
timestamp	uint 64	Encapsulation time
hmac	uint 256	Authentication header (HMAC-SHA-256-128)
size	uint 32	Payload size

Types

The type is the list of format encapsulated within the D4 protocol.

Type	Description
0	Reserved
1	pcap (libpcap 2.4)
2	meta header (JSON)
3	generic log line
4	dnscap output
5	pcapng (diagnostic)
6	generic NDJSON or JSON Lines
7	generic YAF (Yet Another Flowmeter)
8	passivedns CSV stream
254	type defined by meta header (type 2)

The D4 type list is available in JSON format.

Meta types (via meta header)

Sample meta type JSON (type 2). If a new session is open, before sending D4 packet type 254, a type 2 packet MUST be sent to describe to the D4 server how to decode packets. A meta header payload contains a single JSON object which describes the next packet to be decoded as type 254 in the stream. The JSON object MUST at least contain a type field.

{
  "type": "ja3-jl",
  "encoding": "utf-8",
  "tags": [
    "tlp:white"
  ],
  "misp:org": "5b642239-4db4-4580-adf4-4ebd950d210f"
}

Type	Description
ja3-jl	JA3 fingerprinting JL version
d4-telemetry	D4 project sensor telemetry
fascia	fascia JSON object