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The HTTP/S protocol supports a url for heartbeating and acknowledging operations. These endpoints support the JSON structures defined below. C2 agents must send a heartbeat, defined above, to update the C2 server of its status and to receive operations. The frequency of these calls are up to the C2 agent to define.
CoAP Protocol
The CoAP protocol (https://coap.technology/) supports a constrained protocol for smaller devices. In the case of CoAP, the base requirements, as listed above, are fulfilled in each message. While the heartbeat structure, below, contains optional elements, the CoAP protocol implemented in Apache NiFi MiNiFi C++ contains minimal information per heartbeat.
Heartbeat structure
Heartbeats consist of a POST of the following Schema to the C2 heartbeat url. Metrics is a configurable list of metrics that can be returned, so the entirety of that object is optional. AvailableClasses in the structure below is optional.
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