rfc1445.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

                 authInfo
                    ANY, -- defined by authentication protocol
                 authData
                    SnmpMgmtCom
               }

          For each SnmpAuthMsg value that represents a SNMPv2
          authenticated management communication, the following
          statements are true:

          o    Its authInfo component is called the authentication
               information and represents information required in
               support of the authentication protocol used by the SNMPv2
               party originating the message.  The detailed significance
               of the authentication information is specific to the
               authentication protocol in use; it has no effect on the
               application semantics of the communication other than its
               use by the authentication protocol in determining whether
               the communication is authentic or not.

          o    Its authData component is called the authentication data
               and represents a SNMPv2 management communication.

















          Galvin & McCloghrie                                  [Page 12]





          RFC 1445       Administrative Model for SNMPv2      April 1993


          2.11.  SNMPv2 Private Management Communication

          A SNMPv2 private management communication is a SNMPv2
          authenticated management communication (see Section 2.10) that
          is (possibly) protected from disclosure.  A private management
          communication is represented by an ASN.1 value with the
          following syntax:

               SnmpPrivMsg ::= [1] IMPLICIT SEQUENCE {
                 privDst
                    OBJECT IDENTIFIER,
                 privData
                    [1] IMPLICIT OCTET STRING
               }

          For each SnmpPrivMsg value that represents a SNMPv2 private
          management communication, the following statements are true:

          o    Its privDst component is called the privacy destination
               and identifies the SNMPv2 party to which the
               communication is directed.

          o    Its privData component is called the privacy data and
               represents the (possibly encrypted) serialization
               (according to the conventions of [5]) of a SNMPv2
               authenticated management communication (see Section
               2.10).























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          2.12.  SNMPv2 Management Communication Class

          A SNMPv2 management communication class corresponds to a
          specific SNMPv2 PDU type defined in [2].  A management
          communication class is represented by an ASN.1 INTEGER value
          according to the type of the identifying PDU (see Table 1).


                              Get              1
                              GetNext          2
                              Response         4
                              Set              8
                              -- unused       16
                              GetBulk         32
                              Inform          64
                              SNMPv2-Trap    128


                    Table 1: Management Communication Classes


          The value by which a communication class is represented is
          computed as 2 raised to the value of the ASN.1 context-
          specific tag for the appropriate SNMPv2 PDU.

          A set of management communication classes is represented by
          the ASN.1 INTEGER value that is the sum of the representations
          of the communication classes in that set.  The null set is
          represented by the value zero.


          2.13.  SNMPv2 Access Control Policy

          A SNMPv2 access control policy is a specification of a local
          access policy in terms of a SNMPv2 context and the management
          communication classes which are authorized between a pair of
          SNMPv2 parties.  Architecturally, such a specification
          comprises four parts:

          o    the targets of SNMPv2 access control - the SNMPv2 parties
               that may perform management operations as requested by
               management communications received from other parties,

          o    the subjects of SNMPv2 access control - the SNMPv2
               parties that may request, by sending management





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          RFC 1445       Administrative Model for SNMPv2      April 1993


               communications to other parties, that management
               operations be performed,

          o    the managed object resources of SNMPv2 access control -
               the SNMPv2 contexts which identify the management
               information on which requested management operations are
               to be performed, and

          o    the policy that specifies the classes of SNMPv2
               management communications pertaining to a particular
               SNMPv2 context that a particular target is authorized to
               accept from a particular subject.

          Conceptually, a SNMPv2 access policy is represented by a
          collection of ASN.1 values with the following syntax:

               AclEntry ::= SEQUENCE {
                 aclTarget
                    OBJECT IDENTIFIER,
                 aclSubject
                    OBJECT IDENTIFIER,
                 aclResources
                    OBJECT IDENTIFIER,
                 aclPrivileges
                    INTEGER
               }

          For each such value that represents one part of a SNMPv2
          access policy, the following statements are true:

          o    Its aclTarget component is called the target and
               identifies the SNMPv2 party to which the partial policy
               permits access.

          o    Its aclSubject component is called the subject and
               identifies the SNMPv2 party to which the partial policy
               grants privileges.

          o    Its aclResources component is called the managed object
               resources and identifies the SNMPv2 context referenced by
               the partial policy.

          o    Its aclPrivileges component is called the privileges and
               represents a set of SNMPv2 management communication
               classes which, when they reference the specified SNMPv2





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          RFC 1445       Administrative Model for SNMPv2      April 1993


               context, are authorized to be processed by the specified
               target party when received from the specified subject
               party.

          The application of SNMPv2 access control policy only occurs on
          receipt of management communications; it is not applied on
          transmission of management communications.  Note, however,
          that ASN.1 values, having the syntax AclEntry, are also used
          in determining the destinations of a SNMPv2-Trap [2].









































          Galvin & McCloghrie                                  [Page 16]





          RFC 1445       Administrative Model for SNMPv2      April 1993


          3.  Elements of Procedure

          This section describes the procedures followed by a SNMPv2
          entity in processing SNMPv2 messages.  These procedures are
          independent of the particular authentication and privacy
          protocols that may be in use.


          3.1.  Generating a Request

          This section describes the procedure followed by a SNMPv2
          entity whenever either a management request or a trap
          notification is to be transmitted by a SNMPv2 party.

          (1)  A SnmpMgmtCom value is constructed for which the srcParty
               component identifies the originating party, for which the
               dstParty component identifies the receiving party, for
               which the context component identifies the desired SNMPv2
               context, and for which the pdu component represents the
               desired management operation.

          (2)  The local database of party information is consulted to
               determine the authentication protocol and other relevant
               information for the originating and receiving SNMPv2
               parties.

          (3)  A SnmpAuthMsg value is constructed with the following
               properties:

                    Its authInfo component is constructed according to
                    the authentication protocol specified for the
                    originating party.

                      In particular, if the authentication protocol for
                      the originating SNMPv2 party is identified as
                      noAuth, then this component corresponds to the
                      OCTET STRING value of zero length.

                   Its authData component is the constructed SnmpMgmtCom
                   value.

          (4)  The local database of party information is consulted to
               determine the privacy protocol and other relevant
               information for the receiving SNMPv2 party.






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          RFC 1445       Administrative Model for SNMPv2      April 1993


          (5)  A SnmpPrivMsg value is constructed with the following
               properties:

                    Its privDst component identifies the receiving
                    SNMPv2 party.

                    Its privData component is the (possibly encrypted)
                    serialization of the SnmpAuthMsg value according to
                    the conventions of [5].

                      In particular, if the privacy protocol for the
                      receiving SNMPv2 party is identified as noPriv,
                      then the privData component is unencrypted.
                      Otherwise, the privData component is processed
                      according to the privacy protocol.

          (6)  The constructed SnmpPrivMsg value is serialized according
               to the conventions of [5].

          (7)  The serialized SnmpPrivMsg value is transmitted using the