BRSKI discovery and variations

Bootstrapping Remote Secure Key Infrastructure (BRSKI) is a protocol to enroll pledge devices automatically and secure with a registrar of an owner, relying also on proxies to facilitate the communication and Manufacturer Authorized Signing Authorities (MASA) and Certificate Authorities (CA) to enable the enrollment. This document specifies how to make BRSKI communications autoconfiguring, extensible and resilient in the face of simultaneous use of different variations of the BRSKI protocol (BRSKI, BRSKI-AE, BRSKI-PRM, constrained BRSKI, stateless constrained BRSKI proxies). This document specifies a data model, IANA registry and BRSKI component procedures to achieve this. This document does not define any new discovery methods. Instead, its data model allows signaling of all current (and future) variations of the BRSKI family of protocols consistently via different existing network discovery mechanisms: DNS-SD, CoAP discovery (CORE-LF) and GRASP. Additional/future discovery mechanisms can also be supported through the IANA registry. Automatic resiliency and load-sharing are enabled through the use of discovery mechanisms and the provisioning of multiple instances of BRSKI components such as registrars and Join Proxies. This document specifies the procedures to support load-sharing and (fast) failover under failure and recovery of redundant components. Future-proof deployments of BRSKI require Join Proxies that automatically support any current and future BRSKI variation. This document specifies the procedures by which Join Proxies can support this through specific Join Proxy protocol behavior and the use of discovery mechanisms. The specification of discovery of pledges by their IDevID as introduced by BRSKI-PRM is refined in this document.