4.2. Receiving a Message

This section describes the behavior of a SNMPv2 entity when it acts as a SNMPv2 party for which the privacy protocol is administratively specified as the Symmetric Privacy Protocol. Insofar as the behavior of a SNMPv2 entity when receiving a protocol message is defined generically in [1], only those aspects of that behavior that are specific to the Symmetric Privacy Protocol are described below.

According to Section 3.2 of [1], the privData component of a received SnmpPrivMsg value is evaluated during Step 4 of generic processing. In particular, it states the privData component is evaluated according to the privacy protocol identified for the SNMPv2 party receiving the message. When the relevant privacy protocol is the Symmetric Privacy Protocol, the procedure performed by a SNMPv2 entity whenever a management communication is received by a SNMPv2 party is as follows.

1. The local database is consulted to determine the private privacy key of the SNMPv2 party receiving the message (represented, for example, according to the conventions defined in Section 1.5.2).

2. The contents octets of the privData component are decrypted using, for example, the algorithm specified in Section 1.5.2 and the extracted private privacy key.

Processing of the received message continues as specified in [1].