SNMP_USM(3)						   BSD Library Functions Manual 					       SNMP_USM(3)

NAME

     snmp_usm -- user-based security module for bsnmpd(1)

LIBRARY

     (begemotSnmpdModulePath."usm" = /usr/lib/snmp_usm.so)

DESCRIPTION

     The snmp_usm module implements SNMPv3 User-Based Security Model MIB as defined in RFC 3414.  The module is used to manage the internal list
     of SNMPv3 USM active users in bsnmpd.  The module must be loaded for bsnmpd to receive and process SNMPv3 USM PDUs correctly.

IMPLEMENTATION NOTES

     A short description of the objects in the MIB follows.

     usmStats	The subtree contains statistics for the User-based Security Model PDU processing.  The statistics are reset each time the module
		is loaded.

     usmUserSpinLock
		An advisory lock used to coordinate several Command Generator Applications when altering the SNMP USM users.

     usmUserTable
		The table contains all SNMP USM users configured in bsnmpd.  The table contains the following objects

		usmUserEngineID  An SNMP engine's administratively-unique identifier. Must be set to the same Engine ID as bsnmpd so that the user
				 will actually be allowed to communicate with the daemon.  The column is used as entry key and is not accessible
				 for GET or SET operations.

		usmUserName	 The USM user name. The second entry key, again not accessible for GET or SET operations.

		usmUserSecurityName
				 The column has the exact same value as the usmUserName column, however is accessible for GET operations.

		usmUserCloneFrom
				 A GET on this column will return an empty OID. SET operations are currently not supported.

		usmUserAuthProtocol
				 The value of this column contains the OID corresponding to the authentication protocol used by the USM user. The
				 following protocols and their OIDs are known to snmp_usm module

				 NoAuthProtocol 1.3.6.1.6.3.10.1.1.1

				 HMACMD5AuthProtocol 1.3.6.1.6.3.10.1.1.2

				 HMACSHAAuthProtocol 1.3.6.1.6.3.10.1.1.3

		usmUserAuthKeyChange, usmUserOwnAuthKeyChange
				 These columns may be used to change the user's authentication key.

		usmUserPrivProtocol
				 The value of this column contains the OID corresponding to the privacy protocol used by the USM user. The follow-
				 ing protocols and their OIDs are known to snmp_usm module

				 NoPrivProtocol 1.3.6.1.6.3.10.1.2.1

				 DESPrivProtoco 1.3.6.1.6.3.10.1.2.2

				 AesCfb128Protocol 1.3.6.1.6.3.10.1.2.4

		usmUserPrivKeyChange, usmUserOwnPrivKeyChange
				 These columns may be used to change the user's privacy key.

		usmUserPublic	 An arbitrary octet string that may be modified to confirm a SET operation on any of the columns was successful.

		usmUserStorageType
				 This column always has either of two values. Entries created via bsnmpd's configuration file always have this
				 column set to readOnly (5) and it is not possible to modify those entries. Entries created by Command Generator
				 Applications always have this column set to volatile(2) and such entries are lost when the module is restarted. A
				 SET operation on this column is not allowed.

		usmUserStatus	 This column is used to create new USM user entries or delete existing ones from the table.

FILES

     /usr/share/snmp/defs/usm_tree.def
		The description of the MIB tree implemented by snmp_usm.

SEE ALSO

     bsnmpd(1), gensnmptree(1), snmpmod(3)

STANDARDS

     IETF RFC 3414

AUTHORS

     Shteryana Shopova <syrinx@FreeBSD.org>

BSD
								 September 9, 2010							       BSD