snmp_v3.h File Reference

SNMPv3 User-based Security Model (USM) layer (DETWS_ENABLE_SNMP_V3). More...

#include "ServerConfig.h"
#include <stddef.h>
#include <stdint.h>

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Detailed Description

SNMPv3 User-based Security Model (USM) layer (DETWS_ENABLE_SNMP_V3).

Adds authenticated and optionally encrypted SNMPv3 on top of the v1/v2c agent: the v3 message framing (RFC 3412), engine discovery + timeliness (RFC 3414), USM authentication and privacy. The decrypted, authenticated inner PDU is dispatched through the shared MIB core (`snmp_dispatch_pdu()`), so v1/v2c and v3 expose the same objects.

Protocols implemented (a single authPriv user):

• Auth: usmHMAC192SHA256 (HMAC-SHA-256, 24-byte digest; RFC 7860) - net-snmp -a SHA-256.
• Priv: usmAesCfb128 (AES-128-CFB; RFC 3826) - net-snmp -x AES.

The agent is the authoritative engine, so the per-user localized keys are derived once in snmp_v3_set_user() (no per-request 1 MB key expansion).

Definition in file snmp_v3.h.