Module dtls 

DTLS session management for EST-coaps transport security.

RFC 9483 §5 mandates DTLS to secure all EST-coaps exchanges. This module provides session tracking and caching abstractions that a concrete DTLS implementation (e.g., OpenSSL, mbedTLS, or rustls with DTLS support) would integrate with.

Session Resumption

Constrained devices benefit significantly from DTLS session resumption (RFC 6347 §4.2.8, RFC 9147 §5) because the full handshake involves multiple round trips and is computationally expensive, especially with post-quantum key exchange (ML-KEM).

The DtlsSessionCache provides a bounded, TTL-expiring cache of established sessions keyed by peer address.

Structs

ClientCertInfo

Client certificate information extracted from a DTLS handshake.

DtlsSession

An established DTLS session for a CoAP/EST-coaps connection.

DtlsSessionCache

A bounded, TTL-expiring cache of DTLS sessions keyed by peer address.

Enums

DtlsVersion

DTLS protocol version.