Internet-Draft TLS 1.3 Transport Model for SNMP June 2021
Vaughn Expires 29 December 2021 [Page]
Workgroup:
Internet Engineering Task Force
Internet-Draft:
draft-vaughn-tlstm-update-01
Updates:
6353 (if approved)
Published:
Intended Status:
Standards Track
Expires:
Author:
K. Vaughn, Ed.
Trevilon LLC

Transport Layer Security Verion 1.3 (TLS 1.3) Transport Model for the Simple Network Management Protocol Version 3 (SNMPv3)

Abstract

This document updates the TLS Transport Model (TLSTM), as defined in [RFC6353], to support Transport Layer Security Version 1.3 (TLS) [RFC8446] and Datagram Transport Layer Security Version 1.3 (DTLS) [I-D.ietf-tls-dtls13], which are jointly known as "(D)TLS". This document may be applicable to future versions of SNMP and (D)TLS.

This document updates the SNMP-TLS-TM-MIB as defined in [RFC6353].

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 29 December 2021.

1. Introduction

This document updates the fingerprint algorithm defined by [RFC6353] to support the ciphersuites used by Transport Layer Security Version 1.3 (TLS) and Datagram Transport Layer Security Version 1.3 (DTLS), which are jointly known as "(D)TLS". The update also incorporates other less critical updates. Although the title and text of this document specifically reference SNMPv3 and (D)TLS 1.3, this document may be applicable to future versions of these protocols.

1.1. Conventions

Within this document the terms "TLS", "DTLS", "(D)TLS", "SNMP", and "TLSTM" mean "TLS 1.3", "DTLS 1.3", "TLS 1.3 and/or DTLS 1.3", "SMNPv3", and "TLSTM 1.3", respectively. These version numbers are only used when the text needs to emphasize version numbers, such as within the title. When this document refers to any other version of these protocols, it always explicitly states the version intended.

For consistency with SNMP-related specifications, this document favors terminology as defined in [STD62], rather than favoring terminology that is consistent with non-SNMP specifications. This is consistent with the IESG decision to not require the SNMPv3 terminology be modified to match the usage of other non-SNMP specifications when SNMPv3 was advanced to a Full Standard. "Authentication" in this document typically refers to the English meaning of "serving to prove the authenticity of" the message, not data source authentication or peer identity authentication. The terms "manager" and "agent" are not used in this document because, in the RFC3411 architecture, all SNMP entities have the capability of acting as manager, agent, or both depending on the SNMP application types supported in the implementation. Where distinction is necessary, the application names of command generator, command responder, notification originator, notification receiver, and proxy forwarder are used. See "SNMP Applications" (RFC3411) for further information.

Throughout this document, the terms "client" and "server" are used to refer to the two ends of the TLS transport connection. The client actively opens the TLS connection, and the server passively listens for the incoming TLS connection. An SNMP entity MAY act as a TLS client or server or both, depending on the SNMP applications supported.

While TLS frequently refers to a user, the terminology preferred in RFC3411 and in this memo is "principal". A principal is the "who" on whose behalf services are provided or processing takes place. A principal can be, among other things, an individual acting in a particular role; a set of individuals, with each acting in a particular role; an application or a set of applications, or a combination of these within an administrative domain.

Throughout this document, the term "session" is used to refer to a secure association between two TLS Transport Models that permits the transmission of one or more SNMP messages within the lifetime of the session. The TLS protocol also has an internal notion of a session and although these two concepts of a session are related, when the term "session" is used this document is referring to the TLSTM's specific session and not directly to the TLS protocol's session.

The User-Based Security Model (USM) (RFC3414) is a mandatory-to- implement Security Model in [STD62]. The USM derives the securityName and securityLevel from the SNMP message received, even when the message was received over a secure transport. It is RECOMMENDED that deployments that support the TLSTM disable the USM, if it has been implemented.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", NOT RECOMMENDED, "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2. Changes from RFC 6353

This document updates [RFC6353]. The changes from [RFC6353] are defined in the following clauses.

2.1. TLSTM Fingerprint

[RFC6353] defines a fingerprint algorithm that references the one-octet TLS 1.2 hash algorithm identifier. TLS 1.3 replaced the one-octet hash algorithm identifier with a two-octet TLS 1.3 cipher suite identifier thereby breaking the algorithm defined in [RFC6353]. The update to the SNMP-TLS-TM-MIB, as defined in Section 4, deprecates the original fingerprint TEXTUAL-CONVENTION and replaces it with a new TEXTUAL-CONVENTION.

The change also required an update to several objects within the tables defined within the SNMP-TLS-TM-MIB; further these objects are referernced by other (e.g., RowStatus) objects in a manner that requires deprecating and replacing the tables in their entirety. Thus, while the number of objects deprecated and replaced is significant the semantics of the changes are minor.

References to the older objects within [RFC6353] are applicable to the replacement objects. The newer objects are identified with names similar to those used in the original MIB but with a "13" inserted to reference TLS 1.3.

2.2. Security Level

The RFC3411 architecture recognizes three levels of security:

  • without authentication and without privacy (noAuthNoPriv)
  • with authentication but without privacy (authNoPriv)
  • with authentication and with privacy (authPriv)

With (D)TLS 1.3, authentication and privacy are always provided. Hence, all exchanges conforming to the rules of this document will include authentication and privacy, regardless of the security level requested. This is consistent with what was prescribed in RFC6353, where a TLS Transport Model is expected to provide for outgoing connections with a security level at least that of the requested security level.

2.3. TLS Version

[RFC6353] stated that TLSTM clients and servers MUST NOT request, offer, or use SSL 2.0. This document extends this statement such that TLSTM clients and servers MUST NOT request, offer, or use SSL 3.0, (D)TLSv 1.0, (D)TLS v1.1. See Appendix D.5 of [RFC8446] for further details. For backward compatibility issues with older TLS versions, see Appendix D of [RFC8446].

An implementation that supports these older protocols is not considered conformant to the TLSTM while the older protocols are enabled.

2.4. SNMP Version

[RFC6353] stated that using a non-transport-aware Security Model with a secure Transport Model was not recommended. This document tightens this statement such that TLSTM clients and servers MUST NOT request, offer, or use SNMPv1 or SNMPv2c message processing described in [RFC3584], or the User-based Security Model of SNMPv3.

An implementation that supports these older protocols is not considered conformant to the TLSTM while the older protocols are enabled.

2.5. Common Name

[RFC6353] stated that the use of a certificate's CommonName is deprecated and users were encouraged to use the subjectAltName. This document tightens this statement such that TLSTM clients and servers MUST NOT use the CommonName.

3. Additional Rules for TLS 1.3

This document specifies additional rules and clarifications for the use of TLS 1.3.

3.1. Zero Round Trip Time Resumption (0-RTT)

TLS 1.3 implementations for SNMPv3 MUST NOT enable the 0-RTT mode of session resumption (either sending or accepting) and MUST NOT automatically resend 0-RTT data if it is rejected by the server. The reason 0-RTT is disallowed is that there are no "safe" messages that if replayed will be guaranteed to cause no harm at a server side: all incoming notification or command responses are meant to be acted upon only once. See Security considerations section for further details.

TLS TM clients and servers MUST NOT request, offer or use the 0-RTT mode of TLS 1.3. [RFC8446] removed the renegotiation supported in TLS 1.2 [RFC5246]; for session resumption, it introduced a zero-RTT (0-RTT) mode, saving a round-trip at connection setup at the cost of increased risk of replay attacks (it is possible for servers to guard against this attack by keeping track of all the messages received). [RFC8446] requires a profile be written for any application that wants to use 0-RTT, specifying which messages are "safe to use" on this mode. The reason 0-RTT is disallowed here is that there are no "safe" SNMPv3 messages that if replayed will be sure to cause no harm at a server side: all incoming notification or command responses have consequences and are to be acted upon only once.

Renegotiation of sessions is not supported as it is not supported by TLS 1.3.

3.2. TLS ciphersuites, extensions and protocol invariants

[RFC8446] section 9 requires that, in the absence of application profiles, certain cipher suites, TLS extensions, and TLS protocol invariants are mandatory to implement. This document does not specify an application profile, hence all of the compliance requirements in [RFC8446] apply.

4. MIB Module Definition

SNMP-TLS-TM-MIB DEFINITIONS ::= BEGIN
IMPORTS
  MODULE-IDENTITY, OBJECT-TYPE,
  OBJECT-IDENTITY, mib-2, snmpDomains,
  Counter32, Unsigned32, Gauge32, NOTIFICATION-TYPE
    FROM SNMPv2-SMI                 -- RFC 2578 or any update thereof
  TEXTUAL-CONVENTION, TimeStamp, RowStatus, StorageType,
  AutonomousType
    FROM SNMPv2-TC                  -- RFC 2579 or any update thereof
  MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
    FROM SNMPv2-CONF                -- RFC 2580 or any update thereof
  SnmpAdminString
    FROM SNMP-FRAMEWORK-MIB         -- RFC 3411 or any update thereof
  snmpTargetParamsName, snmpTargetAddrName
    FROM SNMP-TARGET-MIB            -- RFC 3413 or any update thereof
    ;
snmpTlstmMIB MODULE-IDENTITY
  LAST-UPDATED "202106220000Z"

  ORGANIZATION "ISMS Working Group"
  CONTACT-INFO "Kenneth Vaughn
                Trevilon LLC
                6606 FM 1488 RD, STE 503
                Magnolia, TX 77354
                USA
                kvaughn@trevilon.com
  DESCRIPTION  "
      The TLS Transport Model MIB
      Copyright (c) 2010-2021 IETF Trust and the persons identified
      as authors of the code.  All rights reserved.
      Redistribution and use in source and binary forms, with or
      without modification, is permitted pursuant to, and subject
      to the license terms contained in, the Simplified BSD License
      set forth in Section 4.c of the IETF Trust's Legal Provisions
      Relating to IETF Documents
      (http://trustee.ietf.org/license-info)."
     REVISION     "202106220000Z"
     DESCRIPTION  "This version of this MIB module is part of
                   RFC XXXX; see the RFC itself for full legal
                   notices.  This version updated the MIB to
                   support (D)TLS 1.3."

     REVISION     "201107190000Z"
     DESCRIPTION  "This version of this MIB module is part of
                   RFC 6353; see the RFC itself for full legal
                   notices.  The only change was to introduce
                   new wording to reflect require changes for
                   IDNA addresses in the SnmpTLSAddress TC."

     REVISION     "201005070000Z"
     DESCRIPTION  "This version of this MIB module is part of
                   RFC 5953; see the RFC itself for full legal
                   notices."
  ::= { mib-2 198 }
-- ************************************************
-- subtrees of the SNMP-TLS-TM-MIB
-- ************************************************
snmpTlstmNotifications OBJECT IDENTIFIER ::= { snmpTlstmMIB 0 }
snmpTlstmIdentities    OBJECT IDENTIFIER ::= { snmpTlstmMIB 1 }
snmpTlstmObjects       OBJECT IDENTIFIER ::= { snmpTlstmMIB 2 }
snmpTlstmConformance   OBJECT IDENTIFIER ::= { snmpTlstmMIB 3 }
-- ************************************************
-- snmpTlstmObjects - Objects
-- ************************************************
snmpTLSTCPDomain OBJECT-IDENTITY
  STATUS      current
  DESCRIPTION
      "The SNMP over TLS via TCP transport domain.  The
      corresponding transport address is of type SnmpTLSAddress.
      The securityName prefix to be associated with the
      snmpTLSTCPDomain is 'tls'.  This prefix may be used by
      security models or other components to identify which secure
      transport infrastructure authenticated a securityName."
  REFERENCE
    "RFC 2579: Textual Conventions for SMIv2"
  ::= { snmpDomains 8 }
snmpDTLSUDPDomain OBJECT-IDENTITY
  STATUS      deprecated
  DESCRIPTION
      "The SNMP over DTLS via UDP transport domain.  The
      corresponding transport address is of type SnmpTLSAddress.
      The securityName prefix to be associated with the
      snmpDTLSUDPDomain is 'dtls'.  This prefix may be used by
      security models or other components to identify which secure
      transport infrastructure authenticated a securityName."
  REFERENCE
    "RFC 2579: Textual Conventions for SMIv2"
  ::= { snmpDomains 9 }
SnmpTLSAddress ::= TEXTUAL-CONVENTION
  DISPLAY-HINT "1a"
  STATUS       current
  DESCRIPTION
     "Represents an IPv4 address, an IPv6 address, or a
      US-ASCII-encoded hostname and port number.
      An IPv4 address must be in dotted decimal format followed by a
      colon ':' (US-ASCII character 0x3A) and a decimal port number
      in US-ASCII.
      An IPv6 address must be a colon-separated format (as described
      in RFC 5952), surrounded by square brackets ('[', US-ASCII
      character 0x5B, and ']', US-ASCII character 0x5D), followed by
      a colon ':' (US-ASCII character 0x3A) and a decimal port number
      in US-ASCII.
      A hostname is always in US-ASCII (as per RFC 1123);
      internationalized hostnames are encoded as A-labels as
      specified in  RFC 5890.  The hostname is followed by a
      colon ':' (US-ASCII character 0x3A) and a decimal port number
      in US-ASCII.  The name SHOULD be fully qualified whenever
      possible.
      Values of this textual convention may not be directly usable
      as transport-layer addressing information, and may require
      run-time resolution.  As such, applications that write them
      must be prepared for handling errors if such values are not
      supported, or cannot be resolved (if resolution occurs at the
      time of the management operation).
      The DESCRIPTION clause of TransportAddress objects that may
      have SnmpTLSAddress values must fully describe how (and
      when) such names are to be resolved to IP addresses and vice
      versa.
      This textual convention SHOULD NOT be used directly in object
      definitions since it restricts addresses to a specific
      format.  However, if it is used, it MAY be used either on its
      own or in conjunction with TransportAddressType or
      TransportDomain as a pair.
      When this textual convention is used as a syntax of an index
      object, there may be issues with the limit of 128
      sub-identifiers specified in SMIv2 (STD 58).  It is
      RECOMMENDED that all MIB documents using this textual
      convention make explicit any limitations on index component
      lengths that management software must observe.  This may be
      done either by including SIZE constraints on the index
      components or by specifying applicable constraints in the
      conceptual row DESCRIPTION clause or in the surrounding
      documentation."
  REFERENCE
    "RFC 1123: Requirements for Internet Hosts - Application and
               Support
     RFC 5890: Internationalized Domain Names for Applications
               (IDNA): Definitions and Document Framework
     RFC 5952: A Recommendation for IPv6 Address Text Representation
    "
   SYNTAX       OCTET STRING (SIZE (1..255))
SnmpTLSFingerprint ::= TEXTUAL-CONVENTION
  DISPLAY-HINT "1x:1x"
  STATUS       deprecated
  DESCRIPTION
     "A fingerprint value that can be used to uniquely reference
     other data of potentially arbitrary length.
     An SnmpTLSFingerprint value is composed of a 1-octet hashing
     algorithm identifier followed by the fingerprint value.  The
     octet value encoded is taken from the IANA TLS HashAlgorithm
     Registry (RFC 5246).  The remaining octets are filled using the
     results of the hashing algorithm.
     This TEXTUAL-CONVENTION allows for a zero-length (blank)
     SnmpTLSFingerprint value for use in tables where the
     fingerprint value may be optional.  MIB definitions or
     implementations may refuse to accept a zero-length value as
     appropriate.
     This textual convention was deprecated because TLS 1.3 uses a
     2-octet cipher suite identifier rather than a 1-octet hashing
     algorithm identifier."
  REFERENCE "RFC 5246: The Transport Layer
             Security (TLS) Protocol Version 1.2
             http://www.iana.org/assignments/tls-parameters/
  "
  SYNTAX OCTET STRING (SIZE (0..255))
SnmpTLS13Fingerprint ::= TEXTUAL-CONVENTION
  DISPLAY-HINT "1x,1x"
  STATUS       current
  DESCRIPTION
     "A fingerprint value that can be used to uniquely reference
     other data of potentially arbitrary length.
     An SnmpTLS13Fingerprint value is composed of a 2-octet cipher
     suite identifier followed by the fingerprint value.  The
     octet value encoded is taken from the IANA TLS Cipher Suites
     Registry(RFC 8446).  The remaining octets are filled using the
     results of the hashing algorithm, up to the first 253 octets.
     This TEXTUAL-CONVENTION allows for a zero-length (blank)
     SnmpTLS13Fingerprint value for use in tables where the
     fingerprint value may be optional.  MIB definitions or
     implementations may refuse to accept a zero-length value as
     appropriate."
  REFERENCE "RFC 8446: The Transport Layer
             Security (TLS) Protocol Version 1.3
             http://www.iana.org/assignments/tls-parameters/
  "
  SYNTAX OCTET STRING (SIZE (0..255))
-- Identities for use in the snmpTlstmCertToTSNTable and
-- snmpTlstmCertToTSN13Table
snmpTlstmCertToTSNMIdentities OBJECT IDENTIFIER
  ::= { snmpTlstmIdentities 1 }
snmpTlstmCertSpecified OBJECT-IDENTITY
  STATUS        current
  DESCRIPTION  "Directly specifies the tmSecurityName to be used for
                this certificate.  The value of the tmSecurityName
                to use is specified in the snmpTlstmCertToTSN13Data
                column.  The snmpTlstmCertToTSN13Data column must
                contain a non-zero length SnmpAdminString compliant
                value or the mapping described in this row must be
                considered a failure."
  ::= { snmpTlstmCertToTSNMIdentities 1 }
snmpTlstmCertSANRFC822Name OBJECT-IDENTITY
  STATUS        current
  DESCRIPTION  "Maps a subjectAltName's rfc822Name to a
                tmSecurityName.  The local part of the rfc822Name is
                passed unaltered but the host-part of the name must
                be passed in lowercase.  This mapping results in a
                1:1 correspondence between equivalent subjectAltName
                rfc822Name values and tmSecurityName values except
                that the host-part of the name MUST be passed in
                lowercase.
                Example rfc822Name Field:  FooBar@Example.COM
                is mapped to tmSecurityName: FooBar@example.com."
  ::= { snmpTlstmCertToTSNMIdentities 2 }
snmpTlstmCertSANDNSName OBJECT-IDENTITY
  STATUS        current
  DESCRIPTION  "Maps a subjectAltName's dNSName to a
                tmSecurityName after first converting it to all
                lowercase (RFC 5280 does not specify converting to
                lowercase so this involves an extra step).  This
                mapping results in a 1:1 correspondence between
                subjectAltName dNSName values and the tmSecurityName
                values."
  REFERENCE "RFC 5280 - Internet X.509 Public Key Infrastructure
                Certificate and Certificate Revocation
                List (CRL) Profile."
  ::= { snmpTlstmCertToTSNMIdentities 3 }
snmpTlstmCertSANIpAddress OBJECT-IDENTITY
  STATUS        current
  DESCRIPTION  "Maps a subjectAltName's iPAddress to a
                tmSecurityName by transforming the binary encoded
                address as follows:
                1) for IPv4, the value is converted into a
                   decimal-dotted quad address (e.g., '192.0.2.1').
                2) for IPv6 addresses, the value is converted into a
                   32-character all lowercase hexadecimal string
                   without any colon separators.
                This mapping results in a 1:1 correspondence between
                subjectAltName iPAddress values and the
                tmSecurityName values.
                The resulting length of an encoded IPv6 address is
                the maximum length supported by the View-Based
                Access Control Model (VACM).  Using both the
                Transport Security Model's support for transport
                prefixes (see the SNMP-TSM-MIB's
                snmpTsmConfigurationUsePrefix object for details)
                will result in securityName lengths that exceed what
                VACM can handle."
  ::= { snmpTlstmCertToTSNMIdentities 4 }
snmpTlstmCertSANAny OBJECT-IDENTITY
  STATUS        current
  DESCRIPTION  "Maps any of the following fields using the
                corresponding mapping algorithms:
                |------------+----------------------------|
                | Type       | Algorithm                  |
                |------------+----------------------------|
                | rfc822Name | snmpTlstmCertSANRFC822Name |
                | dNSName    | snmpTlstmCertSANDNSName    |
                | iPAddress  | snmpTlstmCertSANIpAddress  |
                |------------+----------------------------|
                The first matching subjectAltName value found in the
                certificate of the above types MUST be used when
                deriving the tmSecurityName.  The mapping algorithm
                specified in the 'Algorithm' column MUST be used to
                derive the tmSecurityName.
                This mapping results in a 1:1 correspondence between
                subjectAltName values and tmSecurityName values.  The
                three sub-mapping algorithms produced by this
                combined algorithm cannot produce conflicting
                results between themselves."
  ::= { snmpTlstmCertToTSNMIdentities 5 }
snmpTlstmCertCommonName OBJECT-IDENTITY
  STATUS        deprecated
  DESCRIPTION  "Maps a certificate's CommonName to a tmSecurityName
                after converting it to a UTF-8 encoding.  The usage
                of CommonNames is deprecated and users are
                encouraged to use subjectAltName mapping methods
                instead.  This mapping results in a 1:1
                correspondence between certificate CommonName values
                and tmSecurityName values."
  ::= { snmpTlstmCertToTSNMIdentities 6 }

-- The snmpTlstmSession Group
snmpTlstmSession       OBJECT IDENTIFIER ::= { snmpTlstmObjects 1 }
snmpTlstmSessionOpens  OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
     "The number of times an openSession() request has been executed
     as a (D)TLS client, regardless of whether it succeeded or
     failed."
  ::= { snmpTlstmSession 1 }
snmpTlstmSessionClientCloses  OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times a closeSession() request has been
      executed as a (D)TLS client, regardless of whether it
      succeeded or failed."
  ::= { snmpTlstmSession 2 }
snmpTlstmSessionOpenErrors  OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times an openSession() request failed to open a
      session as a (D)TLS client, for any reason."
  ::= { snmpTlstmSession 3 }
snmpTlstmSessionAccepts  OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
     "The number of times a (D)TLS server has accepted a new
     connection from a client and has received at least one SNMP
     message through it."
  ::= { snmpTlstmSession 4 }

snmpTlstmSessionServerCloses  OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times a closeSession() request has been
      executed as a (D)TLS server, regardless of whether it
      succeeded or failed."
  ::= { snmpTlstmSession 5 }
snmpTlstmSessionNoSessions  OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times an outgoing message was dropped because
      the session associated with the passed tmStateReference was no
      longer (or was never) available."
  ::= { snmpTlstmSession 6 }
snmpTlstmSessionInvalidClientCertificates OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times an incoming session was not established
      on a (D)TLS server because the presented client certificate
      was invalid.  Reasons for invalidation include, but are not
      limited to, cryptographic validation failures or lack of a
      suitable mapping row in the snmpTlstmCertToTSNTable or the
      snmpTlstmCertToTSN13Table."
  ::= { snmpTlstmSession 7 }
snmpTlstmSessionUnknownServerCertificate OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times an outgoing session was not established
       on a (D)TLS client because the server certificate presented
       by an SNMP over (D)TLS server was invalid because no
       configured fingerprint or Certification Authority (CA) was
       acceptable to validate it.
       This may result because there was no entry in the
       snmpTlstmAddrTable (or snmpTlstmAddr13Table) or because no
       path could be found to a known CA."
  ::= { snmpTlstmSession 8 }
snmpTlstmSessionInvalidServerCertificates OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of times an outgoing session was not established
       on a (D)TLS client because the server certificate presented
       by an SNMP over (D)TLS server could not be validated even if
       the fingerprint or expected validation path was known.  That
       is, a cryptographic validation error occurred during
       certificate validation processing.
       Reasons for invalidation include, but are not
       limited to, cryptographic validation failures."
  ::= { snmpTlstmSession 9 }
snmpTlstmSessionInvalidCaches OBJECT-TYPE
  SYNTAX       Counter32
  MAX-ACCESS   read-only
  STATUS       current
  DESCRIPTION
      "The number of outgoing messages dropped because the
      tmStateReference referred to an invalid cache."
  ::= { snmpTlstmSession 10 }
-- Configuration Objects
snmpTlstmConfig            OBJECT IDENTIFIER ::= {snmpTlstmObjects 2}
-- Certificate mapping
snmpTlstmCertificateMapping OBJECT IDENTIFIER ::= {snmpTlstmConfig 1}
snmpTlstmCertToTSNCount OBJECT-TYPE
  SYNTAX      Gauge32
  MAX-ACCESS  read-only
  STATUS      deprecated
  DESCRIPTION
      "A count of the number of entries in the
      snmpTlstmCertToTSNTable."
  ::= { snmpTlstmCertificateMapping 1 }
snmpTlstmCertToTSNTableLastChanged OBJECT-TYPE
  SYNTAX      TimeStamp
  MAX-ACCESS  read-only
  STATUS      deprecated
  DESCRIPTION
      "The value of sysUpTime.0 when the snmpTlstmCertToTSNTable was
      last modified through any means, or 0 if it has not been
      modified since the command responder was started."
  ::= { snmpTlstmCertificateMapping 2 }
snmpTlstmCertToTSNTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF SnmpTlstmCertToTSNEntry
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "This table is used by a (D)TLS server to map the (D)TLS
      client's presented X.509 certificate to a tmSecurityName.
      On an incoming (D)TLS/SNMP connection, the client's presented
      certificate must either be validated based on an established
      trust anchor, or it must directly match a fingerprint in this
      table.  This table does not provide any mechanisms for
      configuring the trust anchors; the transfer of any needed
      trusted certificates for path validation is expected to occur
      through an out-of-band transfer.
      Once the certificate has been found acceptable (either by path
      validation or directly matching a fingerprint in this table),
      this table is consulted to determine the appropriate
      tmSecurityName to identify with the remote connection.  This
      is done by considering each active row from this table in
      prioritized order according to its snmpTlstmCertToTSNID value.
      Each row's snmpTlstmCertToTSNFingerprint value determines
      whether the row is a match for the incoming connection:
          1) If the row's snmpTlstmCertToTSNFingerprint value
             identifies the presented certificate, then consider the
             row as a successful match.
          2) If the row's snmpTlstmCertToTSNFingerprint value
             identifies a locally held copy of a trusted CA
             certificate and that CA certificate was used to
             validate the path to the presented certificate, then
             consider the row as a successful match.
      Once a matching row has been found, the
      snmpTlstmCertToTSNMapType value can be used to determine how
      the tmSecurityName to associate with the session should be
      determined.  See the snmpTlstmCertToTSNMapType column's
      DESCRIPTION for details on determining the tmSecurityName
      value.  If it is impossible to determine a tmSecurityName from
      the row's data combined with the data presented in the
      certificate, then additional rows MUST be searched looking for
      another potential match.  If a resulting tmSecurityName mapped
      from a given row is not compatible with the needed
      requirements of a tmSecurityName (e.g., VACM imposes a
      32-octet-maximum length and the certificate derived
      securityName could be longer), then it must be considered an
      invalid match and additional rows MUST be searched looking for
      another potential match.
      If no matching and valid row can be found, the connection MUST
      be closed and SNMP messages MUST NOT be accepted over it.
      Missing values of snmpTlstmCertToTSNID are acceptable and
      implementations should continue to the next highest numbered
      row.  It is recommended that administrators skip index values
      to leave room for the insertion of future rows (for example,
      use values of 10 and 20 when creating initial rows).
      Users are encouraged to make use of certificates with
      subjectAltName fields that can be used as tmSecurityNames so
      that a single root CA certificate can allow all child
      certificate's subjectAltName to map directly to a
      tmSecurityName via a 1:1 transformation.  However, this table
      is flexible to allow for situations where existing deployed
      certificate infrastructures do not provide adequate
      subjectAltName values for use as tmSecurityNames.
      Direct mapping from each individual
      certificate fingerprint to a tmSecurityName is also possible
      but requires one entry in the table per tmSecurityName and
      requires more management operations to completely configure a
      device.
      This table and its associated objects were deprecated because
      the fingerprint format changed to support TLS 1.3. By
      deprecating (and creating an updated) table, rather than just
      the fingerprint object, an implementation is able to support
      both the original TLS and new TLS 1.3 tables while forcing some
      agents to only use TLS 1.3."
  ::= { snmpTlstmCertificateMapping 3 }
snmpTlstmCertToTSNEntry OBJECT-TYPE
  SYNTAX      SnmpTlstmCertToTSNEntry
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "A row in the snmpTlstmCertToTSNTable that specifies a mapping
      for an incoming (D)TLS certificate to a tmSecurityName to use
      for a connection."
  INDEX   { snmpTlstmCertToTSNID }
  ::= { snmpTlstmCertToTSNTable 1 }
SnmpTlstmCertToTSNEntry ::= SEQUENCE {
  snmpTlstmCertToTSNID           Unsigned32,
  snmpTlstmCertToTSNFingerprint  SnmpTLSFingerprint,
  snmpTlstmCertToTSNMapType      AutonomousType,
  snmpTlstmCertToTSNData         OCTET STRING,
  snmpTlstmCertToTSNStorageType  StorageType,
  snmpTlstmCertToTSNRowStatus    RowStatus
}
snmpTlstmCertToTSNID OBJECT-TYPE
  SYNTAX      Unsigned32 (1..4294967295)
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "A unique, prioritized index for the given entry.  Lower
      numbers indicate a higher priority."
  ::= { snmpTlstmCertToTSNEntry 1 }
snmpTlstmCertToTSNFingerprint OBJECT-TYPE
  SYNTAX      SnmpTLSFingerprint (SIZE(1..255))
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "A cryptographic hash of an X.509 certificate.  The results of
      a successful matching fingerprint to either the trusted CA in
      the certificate validation path or to the certificate itself
      is dictated by the snmpTlstmCertToTSNMapType column.
      This object was deprecated because TLS 1.3 uses a 2-octet
      cipher suite identifier rather than a 1-octet hashing algorithm
      identifier."
  ::= { snmpTlstmCertToTSNEntry 2 }
snmpTlstmCertToTSNMapType OBJECT-TYPE
  SYNTAX      AutonomousType
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "Specifies the mapping type for deriving a tmSecurityName from
      a certificate.  Details for mapping of a particular type SHALL
      be specified in the DESCRIPTION clause of the OBJECT-IDENTITY
      that describes the mapping.  If a mapping succeeds it will
      return a tmSecurityName for use by the TLSTM model and
      processing stops.
      If the resulting mapped value is not compatible with the
      needed requirements of a tmSecurityName (e.g., VACM imposes a
      32-octet-maximum length and the certificate derived
      securityName could be longer), then future rows MUST be
      searched for additional snmpTlstmCertToTSNFingerprint matches
      to look for a mapping that succeeds.
      Suitable values for assigning to this object that are defined
      within the SNMP-TLS-TM-MIB can be found in the
      snmpTlstmCertToTSNMIdentities portion of the MIB tree."
  DEFVAL { snmpTlstmCertSpecified }
  ::= { snmpTlstmCertToTSNEntry 3 }
snmpTlstmCertToTSNData OBJECT-TYPE
  SYNTAX      OCTET STRING (SIZE(0..1024))
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "Auxiliary data used as optional configuration information for
      a given mapping specified by the snmpTlstmCertToTSNMapType
      column.  Only some mapping systems will make use of this
      column.  The value in this column MUST be ignored for any
      mapping type that does not require data present in this
      column."
  DEFVAL { "" }
  ::= { snmpTlstmCertToTSNEntry 4 }
snmpTlstmCertToTSNStorageType OBJECT-TYPE
  SYNTAX       StorageType
  MAX-ACCESS   read-create
  STATUS       deprecated
  DESCRIPTION
      "The storage type for this conceptual row.  Conceptual rows
      having the value 'permanent' need not allow write-access to
      any columnar objects in the row."
  DEFVAL      { nonVolatile }
  ::= { snmpTlstmCertToTSNEntry 5 }
snmpTlstmCertToTSNRowStatus OBJECT-TYPE
  SYNTAX      RowStatus
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "The status of this conceptual row.  This object may be used
      to create or remove rows from this table.
      To create a row in this table, an administrator must set this
      object to either createAndGo(4) or createAndWait(5).
      Until instances of all corresponding columns are appropriately
      configured, the value of the corresponding instance of the
      snmpTlstmParamsRowStatus column is notReady(3).
      In particular, a newly created row cannot be made active until
      the corresponding snmpTlstmCertToTSNFingerprint,
      snmpTlstmCertToTSNMapType, and snmpTlstmCertToTSNData columns
      have been set.
      The following objects may not be modified while the
      value of this object is active(1):
          - snmpTlstmCertToTSNFingerprint
          - snmpTlstmCertToTSNMapType
          - snmpTlstmCertToTSNData
      An attempt to set these objects while the value of
      snmpTlstmParamsRowStatus is active(1) will result in
      an inconsistentValue error."
  ::= { snmpTlstmCertToTSNEntry 6 }
-- Maps tmSecurityNames to certificates for use by SNMP-TARGET-MIB
snmpTlstmParamsCount OBJECT-TYPE
  SYNTAX      Gauge32
  MAX-ACCESS  read-only
  STATUS      deprecated
  DESCRIPTION
      "A count of the number of entries in the snmpTlstmParamsTable."
  ::= { snmpTlstmCertificateMapping 4 }
snmpTlstmParamsTableLastChanged OBJECT-TYPE
  SYNTAX      TimeStamp
  MAX-ACCESS  read-only
  STATUS      deprecated
  DESCRIPTION
      "The value of sysUpTime.0 when the snmpTlstmParamsTable
      was last modified through any means, or 0 if it has not been
      modified since the command responder was started."
  ::= { snmpTlstmCertificateMapping 5 }
snmpTlstmParamsTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF SnmpTlstmParamsEntry
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "This table is used by a (D)TLS client when a (D)TLS
      connection is being set up using an entry in the
      SNMP-TARGET-MIB.  It extends the SNMP-TARGET-MIB's
      snmpTargetParamsTable with a fingerprint of a certificate to
      use when establishing such a (D)TLS connection."
  ::= { snmpTlstmCertificateMapping 6 }
snmpTlstmParamsEntry OBJECT-TYPE
  SYNTAX      SnmpTlstmParamsEntry
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "A conceptual row containing a fingerprint hash of a locally
      held certificate for a given snmpTargetParamsEntry.  The
      values in this row should be ignored if the connection that
      needs to be established, as indicated by the SNMP-TARGET-MIB
      infrastructure, is not a certificate and TLS based
      connection.  The connection SHOULD NOT be established if the
      certificate fingerprint stored in this entry does not point to
      a valid locally held certificate or if it points to an
      unusable certificate (such as might happen when the
      certificate's expiration date has been reached)."
  INDEX    { IMPLIED snmpTargetParamsName }
  ::= { snmpTlstmParamsTable 1 }
SnmpTlstmParamsEntry ::= SEQUENCE {
  snmpTlstmParamsClientFingerprint SnmpTLSFingerprint,
  snmpTlstmParamsStorageType       StorageType,
  snmpTlstmParamsRowStatus         RowStatus
}
snmpTlstmParamsClientFingerprint OBJECT-TYPE
  SYNTAX      SnmpTLSFingerprint
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "This object stores the hash of the public portion of a
      locally held X.509 certificate.  The X.509 certificate, its
      public key, and the corresponding private key will be used
      when initiating a TLS connection as a TLS client."
  ::= { snmpTlstmParamsEntry 1 }
snmpTlstmParamsStorageType OBJECT-TYPE
  SYNTAX       StorageType
  MAX-ACCESS   read-create
  STATUS       deprecated
  DESCRIPTION
      "The storage type for this conceptual row.  Conceptual rows
      having the value 'permanent' need not allow write-access to
      any columnar objects in the row."
  DEFVAL      { nonVolatile }
  ::= { snmpTlstmParamsEntry 2 }
snmpTlstmParamsRowStatus OBJECT-TYPE
  SYNTAX      RowStatus
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "The status of this conceptual row.  This object may be used
      to create or remove rows from this table.
      To create a row in this table, an administrator must set this
      object to either createAndGo(4) or createAndWait(5).
      Until instances of all corresponding columns are appropriately
      configured, the value of the corresponding instance of the
      snmpTlstmParamsRowStatus column is notReady(3).
      In particular, a newly created row cannot be made active until
      the corresponding snmpTlstmParamsClientFingerprint column has
      been set.
      The snmpTlstmParamsClientFingerprint object may not be modified
      while the value of this object is active(1).
      An attempt to set these objects while the value of
      snmpTlstmParamsRowStatus is active(1) will result in
      an inconsistentValue error."
  ::= { snmpTlstmParamsEntry 3 }
mpTlstmAddrCount OBJECT-TYPE
  SYNTAX      Gauge32
  MAX-ACCESS  read-only
  STATUS      deprecated
  DESCRIPTION
      "A count of the number of entries in the snmpTlstmAddrTable."
  ::= { snmpTlstmCertificateMapping 7 }
snmpTlstmAddrTableLastChanged OBJECT-TYPE
  SYNTAX      TimeStamp
  MAX-ACCESS  read-only
  STATUS      deprecated
  DESCRIPTION
      "The value of sysUpTime.0 when the snmpTlstmAddrTable
      was last modified through any means, or 0 if it has not been
      modified since the command responder was started."
  ::= { snmpTlstmCertificateMapping 8 }
snmpTlstmAddrTable OBJECT-TYPE
  SYNTAX      SEQUENCE OF SnmpTlstmAddrEntry
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "This table is used by a TLS client when a TLS
      connection is being set up using an entry in the
      SNMP-TARGET-MIB.  It extends the SNMP-TARGET-MIB's
      snmpTargetAddrTable so that the client can verify that the
      correct server has been reached.  This verification can use
      either a certificate fingerprint, or an identity
      authenticated via certification path validation.
      If there is an active row in this table corresponding to the
      entry in the SNMP-TARGET-MIB that was used to establish the
      connection, and the row's snmpTlstmAddrServerFingerprint
      column has non-empty value, then the server's presented
      certificate is compared with the
      snmpTlstmAddrServerFingerprint value (and the
      snmpTlstmAddrServerIdentity column is ignored).  If the
      fingerprint matches, the verification has succeeded.  If the
      fingerprint does not match, then the connection MUST be
      closed.
      If the server's presented certificate has passed
      certification path validation [RFC5280] to a configured
      trust anchor, and an active row exists with a zero-length
      snmpTlstmAddrServerFingerprint value, then the
      snmpTlstmAddrServerIdentity column contains the expected
      host name.  This expected host name is then compared against
      the server's certificate as follows:
        - Implementations MUST support matching the expected host
        name against a dNSName in the subjectAltName extension
        field
        - The '*' (ASCII 0x2a) wildcard character is allowed in the
        dNSName of the subjectAltName extension, but only as the
        left-most (least significant) DNS label in that value.
        This wildcard matches any left-most DNS label in the
        server name.  That is, the subject *.example.com matches
        the server names a.example.com and b.example.com, but does
        not match example.com or a.b.example.com.  Implementations
        MUST support wildcards in certificates as specified above,
        but MAY provide a configuration option to disable them.
        - If the locally configured name is an internationalized
        domain name, conforming implementations MUST convert it to
        the ASCII Compatible Encoding (ACE) format for performing
        comparisons, as specified in Section 7 of [RFC5280].
      If the expected host name fails these conditions then the
      connection MUST be closed.

      If there is no row in this table corresponding to the entry
      in the SNMP-TARGET-MIB and the server can be authorized by
      another, implementation-dependent means, then the connection
      MAY still proceed."
  ::= { snmpTlstmCertificateMapping 9 }
snmpTlstmAddrEntry OBJECT-TYPE
  SYNTAX      SnmpTlstmAddrEntry
  MAX-ACCESS  not-accessible
  STATUS      deprecated
  DESCRIPTION
      "A conceptual row containing a copy of a certificate's
      fingerprint for a given snmpTargetAddrEntry.  The values in
      this row should be ignored if the connection that needs to be
      established, as indicated by the SNMP-TARGET-MIB
      infrastructure, is not a TLS based connection.  If an
      snmpTlstmAddrEntry exists for a given snmpTargetAddrEntry, then
      the presented server certificate MUST match or the connection
      MUST NOT be established.  If a row in this table does not
      exist to match an snmpTargetAddrEntry row, then the connection
      SHOULD still proceed if some other certificate validation path
      algorithm (e.g., RFC 5280) can be used."
  INDEX    { IMPLIED snmpTargetAddrName }
  ::= { snmpTlstmAddrTable 1 }
SnmpTlstmAddrEntry ::= SEQUENCE {
  snmpTlstmAddrServerFingerprint    SnmpTLSFingerprint,
  snmpTlstmAddrServerIdentity       SnmpAdminString,
  snmpTlstmAddrStorageType          StorageType,
  snmpTlstmAddrRowStatus            RowStatus
}
snmpTlstmAddrServerFingerprint OBJECT-TYPE
  SYNTAX      SnmpTLSFingerprint
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "A cryptographic hash of a public X.509 certificate.  This
      object should store the hash of the public X.509 certificate
      that the remote server should present during the TLS
      connection setup.  The fingerprint of the presented
      certificate and this hash value MUST match exactly or the
      connection MUST NOT be established."
  DEFVAL { "" }
  ::= { snmpTlstmAddrEntry 1 }
snmpTlstmAddrServerIdentity OBJECT-TYPE
  SYNTAX      SnmpAdminString
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "The reference identity to check against the identity
      presented by the remote system."
  DEFVAL { "" }
  ::= { snmpTlstmAddrEntry 2 }
snmpTlstmAddrStorageType OBJECT-TYPE
  SYNTAX       StorageType
  MAX-ACCESS   read-create
  STATUS       deprecated
  DESCRIPTION
      "The storage type for this conceptual row.  Conceptual rows
      having the value 'permanent' need not allow write-access to
      any columnar objects in the row."
  DEFVAL      { nonVolatile }
  ::= { snmpTlstmAddrEntry 3 }
snmpTlstmAddrRowStatus OBJECT-TYPE
  SYNTAX      RowStatus
  MAX-ACCESS  read-create
  STATUS      deprecated
  DESCRIPTION
      "The status of this conceptual row.  This object may be used
      to create or remove rows from this table.
      To create a row in this table, an administrator must set this
      object to either createAndGo(4) or createAndWait(5).
      Until instances of all corresponding columns are
      appropriately configured, the value of the
      corresponding instance of the snmpTlstmAddrRowStatus
      column is notReady(3).
      In particular, a newly created row cannot be made active until
      the corresponding snmpTlstmAddrServerFingerprint column has
      been set.
      Rows MUST NOT be active if the snmpTlstmAddrServerFingerprint
      column is blank and the snmpTlstmAddrServerIdentity is set to
      '*' since this would insecurely accept any presented
      certificate.

      The snmpTlstmAddrServerFingerprint object may not be modified
      while the value of this object is active(1).
      An attempt to set these objects while the value of
      snmpTlstmAddrRowStatus is active(1) will result in
      an inconsistentValue error."
  ::= { snmpTlstmAddrEntry 4 }
snmpTlstmCertToTSN13Count OBJECT-TYPE
  SYNTAX      Gauge32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "A count of the number of entries in the
      snmpTlstmCertToTSN13Table."
  ::= { snmpTlstmCertificateMapping 10 }
snmpTlstmCertToTSN13TableLastChanged OBJECT-TYPE
  SYNTAX      TimeStamp
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The value of sysUpTime.0 when the snmpTlstmCertToTSN13Table
      was last modified through any means, or 0 if it has not been
      modified since the command responder was started."
  ::= { snmpTlstmCertificateMapping 11 }
snmpTlstmCertToTSN13Table OBJECT-TYPE
  SYNTAX      SEQUENCE OF SnmpTlstmCertToTSN13Entry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table is used by a TLS 1.3 server to map the TLS 1.3
      client's presented X.509 certificate to a tmSecurityName.
      On an incoming TLS/SNMP connection, the client's presented
      certificate must either be validated based on an established
      trust anchor, or it must directly match a fingerprint in this
      table.  This table does not provide any mechanisms for
      configuring the trust anchors; the transfer of any needed
      trusted certificates for path validation is expected to occur
      through an out-of-band transfer.
      Once the certificate has been found acceptable (either by path
      validation or directly matching a fingerprint in this table),
      this table is consulted to determine the appropriate
      tmSecurityName to identify with the remote connection.  This
      is done by considering each active row from this table in
      prioritized order according to its snmpTlstmCertToTSN13ID
      value. Each row's snmpTlstmCertToTSN13Fingerprint value
      determines whether the row is a match for the incoming
      connection:
          1) If the row's snmpTlstmCertToTSN13Fingerprint value
             identifies the presented certificate, then consider the
             row as a successful match.
          2) If the row's snmpTlstmCertToTSN13Fingerprint value
             identifies a locally held copy of a trusted CA
             certificate and that CA certificate was used to
             validate the path to the presented certificate, then
             consider the row as a successful match.
      Once a matching row has been found, the
      snmpTlstmCertToTSN13MapType value can be used to determine how
      the tmSecurityName to associate with the session should be
      determined.  See the snmpTlstmCertToTSN13MapType column's
      DESCRIPTION for details on determining the tmSecurityName
      value.  If it is impossible to determine a tmSecurityName from
      the row's data combined with the data presented in the
      certificate, then additional rows MUST be searched looking for
      another potential match.  If a resulting tmSecurityName mapped
      from a given row is not compatible with the needed
      requirements of a tmSecurityName (e.g., VACM imposes a
      32-octet-maximum length and the certificate derived
      securityName could be longer), then it must be considered an
      invalid match and additional rows MUST be searched looking for
      another potential match.
      If no matching and valid row can be found, the connection MUST
      be closed and SNMP messages MUST NOT be accepted over it.
      Missing values of snmpTlstmCertToTSN13ID are acceptable and
      implementations should continue to the next highest numbered
      row.  It is recommended that administrators skip index values
      to leave room for the insertion of future rows (for example,
      use values of 10 and 20 when creating initial rows).
      Users are encouraged to make use of certificates with
      subjectAltName fields that can be used as tmSecurityNames so
      that a single root CA certificate can allow all child
      certificate's subjectAltName to map directly to a
      tmSecurityName via a 1:1 transformation.  However, this table
      is flexible to allow for situations where existing deployed
      certificate infrastructures do not provide adequate
      subjectAltName values for use as tmSecurityNames.
      Direct mapping from each individual certificate fingerprint to
      a tmSecurityName is possible but requires one entry in the
      table per tmSecurityName and requires more management
      operations to completely configure a device."
  ::= { snmpTlstmCertificateMapping 12 }
snmpTlstmCertToTSN13Entry OBJECT-TYPE
  SYNTAX      SnmpTlstmCertToTSN13Entry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "A row in the snmpTlstmCertToTSN13Table that specifies a
      mapping for an incoming TLS certificate to a tmSecurityName
      to use for a connection."
  INDEX   { snmpTlstmCertToTSN13ID }
  ::= { snmpTlstmCertToTSN13Table 1 }
SnmpTlstmCertToTSN13Entry ::= SEQUENCE {
  snmpTlstmCertToTSN13ID           Unsigned32,
  snmpTlstmCertToTSN13Fingerprint  SnmpTLS13Fingerprint,
  snmpTlstmCertToTSN13MapType      AutonomousType,
  snmpTlstmCertToTSN13Data         OCTET STRING,
  snmpTlstmCertToTSN13StorageType  StorageType,
  snmpTlstmCertToTSN13RowStatus    RowStatus
}
snmpTlstmCertToTSN13ID OBJECT-TYPE
  SYNTAX      Unsigned32 (1..4294967295)
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "A unique, prioritized index for the given entry.  Lower
      numbers indicate a higher priority."
  ::= { snmpTlstmCertToTSN13Entry 1 }
snmpTlstmCertToTSN13Fingerprint OBJECT-TYPE
  SYNTAX      SnmpTLS13Fingerprint (SIZE(2..255))
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "A cryptographic hash of an X.509 certificate.  The results of
      a successful matching fingerprint to either the trusted CA in
      the certificate validation path or to the certificate itself
      is dictated by the snmpTlstmCertToTSN13MapType column."
  ::= { snmpTlstmCertToTSN13Entry 2 }
snmpTlstmCertToTSN13MapType OBJECT-TYPE
  SYNTAX      AutonomousType
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "Specifies the mapping type for deriving a tmSecurityName from
      a certificate.  Details for mapping of a particular type SHALL
      be specified in the DESCRIPTION clause of the OBJECT-IDENTITY
      that describes the mapping.  If a mapping succeeds it will
      return a tmSecurityName for use by the TLSTM model and
      processing stops.
      If the resulting mapped value is not compatible with the
      needed requirements of a tmSecurityName (e.g., VACM imposes a
      32-octet-maximum length and the certificate derived
      securityName could be longer), then future rows MUST be
      searched for additional snmpTlstmCertToTSN13Fingerprint matches
      to look for a mapping that succeeds.
      Suitable values for assigning to this object that are defined
      within the SNMP-TLS-TM-MIB can be found in the
      snmpTlstmCertToTSNMIdentities portion of the MIB tree."
  DEFVAL { snmpTlstmCertSpecified }
  ::= { snmpTlstmCertToTSN13Entry 3 }
snmpTlstmCertToTSN13Data OBJECT-TYPE
  SYNTAX      OCTET STRING (SIZE(0..1024))
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "Auxiliary data used as optional configuration information for
      a given mapping specified by the snmpTlstmCertToTSN13MapType
      column.  Only some mapping systems will make use of this
      column.  The value in this column MUST be ignored for any
      mapping type that does not require data present in this
      column."
  DEFVAL { "" }
  ::= { snmpTlstmCertToTSN13Entry 4 }
snmpTlstmCertToTSN13StorageType OBJECT-TYPE
  SYNTAX       StorageType
  MAX-ACCESS   read-create
  STATUS       current
  DESCRIPTION
      "The storage type for this conceptual row.  Conceptual rows
      having the value 'permanent' need not allow write-access to
      any columnar objects in the row."
  DEFVAL      { nonVolatile }
  ::= { snmpTlstmCertToTSN13Entry 5 }
snmpTlstmCertToTSN13RowStatus OBJECT-TYPE
  SYNTAX      RowStatus
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "The status of this conceptual row.  This object may be used
      to create or remove rows from this table.
      To create a row in this table, an administrator must set this
      object to either createAndGo(4) or createAndWait(5).
      Until instances of all corresponding columns are appropriately
      configured, the value of the corresponding instance of the
      snmpTlstmParams13RowStatus column is notReady(3).
      In particular, a newly created row cannot be made active until
      the corresponding snmpTlstmCertToTSN13Fingerprint,
      snmpTlstmCertToTSN13MapType, and snmpTlstmCertToTSN13Data
      columns have been set.
      The following objects may not be modified while the
      value of this object is active(1):
          - snmpTlstmCertToTSN13Fingerprint
          - snmpTlstmCertToTSN13MapType
          - snmpTlstmCertToTSN13Data
      An attempt to set these objects while the value of
      snmpTlstmParams13RowStatus is active(1) will result in
      an inconsistentValue error."
  ::= { snmpTlstmCertToTSN13Entry 6 }
snmpTlstmParams13Count OBJECT-TYPE
  SYNTAX      Gauge32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "A count of the number of entries in the
      snmpTlstmParams13Table."
  ::= { snmpTlstmCertificateMapping 13 }
snmpTlstmParams13TableLastChanged OBJECT-TYPE
  SYNTAX      TimeStamp
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The value of sysUpTime.0 when the snmpTlstmParams13Table
      was last modified through any means, or 0 if it has not been
      modified since the command responder was started."
  ::= { snmpTlstmCertificateMapping 14 }
snmpTlstmParams13Table OBJECT-TYPE
  SYNTAX      SEQUENCE OF SnmpTlstmParams13Entry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table is used by a TLS client when a TLS
      connection is being set up using an entry in the
      SNMP-TARGET-MIB.  It extends the SNMP-TARGET-MIB's
      snmpTargetParams13Table with a fingerprint of a certificate to
      use when establishing such a TLS connection."
  ::= { snmpTlstmCertificateMapping 15 }
snmpTlstmParams13Entry OBJECT-TYPE
  SYNTAX      SnmpTlstmParams13Entry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "A conceptual row containing a fingerprint hash of a locally
      held certificate for a given snmpTargetParamsEntry.  The
      values in this row should be ignored if the connection that
      needs to be established, as indicated by the SNMP-TARGET-MIB
      infrastructure, is not a certificate and TLS based
      connection.  The connection SHOULD NOT be established if the
      certificate fingerprint stored in this entry does not point to
      a valid locally held certificate or if it points to an
      unusable certificate (such as might happen when the
      certificate's expiration date has been reached)."
  INDEX    { IMPLIED snmpTargetParamsName }
  ::= { snmpTlstmParams13Table 1 }
SnmpTlstmParams13Entry ::= SEQUENCE {
  snmpTlstmParams13ClientFingerprint SnmpTLS13Fingerprint,
  snmpTlstmParams13StorageType       StorageType,
  snmpTlstmParams13RowStatus         RowStatus
}
snmpTlstmParams13ClientFingerprint OBJECT-TYPE
  SYNTAX      SnmpTLS13Fingerprint
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "This object stores the hash of the public portion of a
      locally held X.509 certificate.  The X.509 certificate, its
      public key, and the corresponding private key will be used
      when initiating a TLS connection as a TLS client."
  ::= { snmpTlstmParams13Entry 1 }
snmpTlstmParams13StorageType OBJECT-TYPE
  SYNTAX       StorageType
  MAX-ACCESS   read-create
  STATUS       current
  DESCRIPTION
      "The storage type for this conceptual row.  Conceptual rows
      having the value 'permanent' need not allow write-access to
      any columnar objects in the row."
  DEFVAL      { nonVolatile }
  ::= { snmpTlstmParams13Entry 2 }
snmpTlstmParams13RowStatus OBJECT-TYPE
  SYNTAX      RowStatus
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "The status of this conceptual row.  This object may be used
      to create or remove rows from this table.
      To create a row in this table, an administrator must set this
      object to either createAndGo(4) or createAndWait(5).
      Until instances of all corresponding columns are appropriately
      configured, the value of the corresponding instance of the
      snmpTlstmParams13RowStatus column is notReady(3).
      In particular, a newly created row cannot be made active until
      the corresponding snmpTlstmParams13ClientFingerprint column has
      been set.
      The snmpTlstmParams13ClientFingerprint object may not be
      modified while the value of this object is active(1).
      An attempt to set these objects while the value of
      snmpTlstmParams13RowStatus is active(1) will result in
      an inconsistentValue error."
  ::= { snmpTlstmParams13Entry 3 }
snmpTlstmAddr13Count OBJECT-TYPE
  SYNTAX      Gauge32
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "A count of the number of entries in the snmpTlstmAddr13Table."
  ::= { snmpTlstmCertificateMapping 16 }
snmpTlstmAddr13TableLastChanged OBJECT-TYPE
  SYNTAX      TimeStamp
  MAX-ACCESS  read-only
  STATUS      current
  DESCRIPTION
      "The value of sysUpTime.0 when the snmpTlstmAddr13Table
      was last modified through any means, or 0 if it has not been
      modified since the command responder was started."
  ::= { snmpTlstmCertificateMapping 17 }
snmpTlstmAddr13Table OBJECT-TYPE
  SYNTAX      SEQUENCE OF SnmpTlstmAddr13Entry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "This table is used by a TLS client when a TLS
      connection is being set up using an entry in the
      SNMP-TARGET-MIB.  It extends the SNMP-TARGET-MIB's
      snmpTargetAddrTable so that the client can verify that the
      correct server has been reached.  This verification can use
      either a certificate fingerprint, or an identity
      authenticated via certification path validation.
      If there is an active row in this table corresponding to the
      entry in the SNMP-TARGET-MIB that was used to establish the
      connection, and the row's snmpTlstmAddr13ServerFingerprint
      column has non-empty value, then the server's presented
      certificate is compared with the
      snmpTlstmAddr13ServerFingerprint value (and the
      snmpTlstmAddr13ServerIdentity column is ignored).  If the
      fingerprint matches, the verification has succeeded.  If the
      fingerprint does not match, then the connection MUST be
      closed.
      If the server's presented certificate has passed
      certification path validation [RFC5280] to a configured
      trust anchor, and an active row exists with a zero-length
      snmpTlstmAddr13ServerFingerprint value, then the
      snmpTlstmAddr13ServerIdentity column contains the expected
      host name.  This expected host name is then compared against
      the server's certificate as follows:
        - Implementations MUST support matching the expected host
        name against a dNSName in the subjectAltName extension
        field.
        - The '*' (ASCII 0x2a) wildcard character is allowed in the
        dNSName of the subjectAltName extension, but only as the
        left-most (least significant) DNS label in that value.
        This wildcard matches any left-most DNS label in the
        server name.  That is, the subject *.example.com matches
        the server names a.example.com and b.example.com, but does
        not match example.com or a.b.example.com.  Implementations
        MUST support wildcards in certificates as specified above,
        but MAY provide a configuration option to disable them.
        - If the locally configured name is an internationalized
        domain name, conforming implementations MUST convert it to
        the ASCII Compatible Encoding (ACE) format for performing
        comparisons, as specified in Section 7 of [RFC5280].
      If the expected host name fails these conditions then the
      connection MUST be closed.

      If there is no row in this table corresponding to the entry
      in the SNMP-TARGET-MIB and the server can be authorized by
      another, implementation-dependent means, then the connection
      MAY still proceed."
  ::= { snmpTlstmCertificateMapping 18 }
snmpTlstmAddr13Entry OBJECT-TYPE
  SYNTAX      SnmpTlstmAddr13Entry
  MAX-ACCESS  not-accessible
  STATUS      current
  DESCRIPTION
      "A conceptual row containing a copy of a certificate's
      fingerprint for a given snmpTargetAddrEntry.  The values in
      this row should be ignored if the connection that needs to be
      established, as indicated by the SNMP-TARGET-MIB
      infrastructure, is not a TLS based connection.  If an
      snmpTlstmAddr13Entry exists for a given snmpTargetAddrEntry,
      then the presented server certificate MUST match or the
      connection MUST NOT be established.  If a row in this table
      does not exist to match an snmpTargetAddrEntry row, then the
      connection SHOULD still proceed if some other certificate
      validation path algorithm (e.g., RFC 5280) can be used."
  INDEX    { IMPLIED snmpTargetAddrName }
  ::= { snmpTlstmAddr13Table 1 }
SnmpTlstmAddr13Entry ::= SEQUENCE {
  snmpTlstmAddr13ServerFingerprint    SnmpTLS13Fingerprint,
  snmpTlstmAddr13ServerIdentity       SnmpAdminString,
  snmpTlstmAddr13StorageType          StorageType,
  snmpTlstmAddr13RowStatus            RowStatus
}
snmpTlstmAddr13ServerFingerprint OBJECT-TYPE
  SYNTAX      SnmpTLS13Fingerprint
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "A cryptographic hash of a public X.509 certificate.  This
      object should store the hash of the public X.509 certificate
      that the remote server should present during the TLS
      connection setup.  The fingerprint of the presented
      certificate and this hash value MUST match exactly or the
      connection MUST NOT be established."
  DEFVAL { "" }
  ::= { snmpTlstmAddr13Entry 1 }
snmpTlstmAddr13ServerIdentity OBJECT-TYPE
  SYNTAX      SnmpAdminString
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "The reference identity to check against the identity
      presented by the remote system."
  DEFVAL { "" }
  ::= { snmpTlstmAddr13Entry 2 }
snmpTlstmAddr13StorageType OBJECT-TYPE
  SYNTAX       StorageType
  MAX-ACCESS   read-create
  STATUS       current
  DESCRIPTION
      "The storage type for this conceptual row.  Conceptual rows
      having the value 'permanent' need not allow write-access to
      any columnar objects in the row."
  DEFVAL      { nonVolatile }
  ::= { snmpTlstmAddr13Entry 3 }
snmpTlstmAddr13RowStatus OBJECT-TYPE
  SYNTAX      RowStatus
  MAX-ACCESS  read-create
  STATUS      current
  DESCRIPTION
      "The status of this conceptual row.  This object may be used
      to create or remove rows from this table.
      To create a row in this table, an administrator must set this
      object to either createAndGo(4) or createAndWait(5).
      Until instances of all corresponding columns are
      appropriately configured, the value of the
      corresponding instance of the snmpTlstmAddr13RowStatus
      column is notReady(3).
      In particular, a newly created row cannot be made active until
      the corresponding snmpTlstmAddr13ServerFingerprint column has
      been set.
      Rows MUST NOT be active if the snmpTlstmAddr13ServerFingerprint
      column is blank and the snmpTlstmAddr13ServerIdentity is set to
      '*' since this would insecurely accept any presented
      certificate.
      The snmpTlstmAddr13ServerFingerprint object may not be modified
      while the value of this object is active(1).
      An attempt to set these objects while the value of
      snmpTlstmAddr13RowStatus is active(1) will result in
      an inconsistentValue error."
  ::= { snmpTlstmAddr13Entry 4 }
-- ************************************************
--  snmpTlstmNotifications - Notifications Information
-- ************************************************
snmpTlstmServerCertificateUnknown NOTIFICATION-TYPE
  OBJECTS { snmpTlstmSessionUnknownServerCertificate }
  STATUS  current
  DESCRIPTION
      "Notification that the server certificate presented by an SNMP
       over (D)TLS server was invalid because no configured
       fingerprint or CA was acceptable to validate it.  This may be
       because there was no entry in the snmpTlstmAddrTable (or
       snmpTlstmAddr13Table) or
       because no path could be found to known Certification
       Authority.
       To avoid notification loops, this notification MUST NOT be
       sent to servers that themselves have triggered the
       notification."
  ::= { snmpTlstmNotifications 1 }
snmpTlstmServerInvalidCertificate NOTIFICATION-TYPE
  OBJECTS { snmpTlstmAddrServerFingerprint,
            snmpTlstmSessionInvalidServerCertificates}
  STATUS  deprecated
  DESCRIPTION
      "Notification that the server certificate presented by an SNMP
       over (D)TLS server could not be validated even if the
       fingerprint or expected validation path was known.  That is, a
       cryptographic validation error occurred during certificate
       validation processing.
       To avoid notification loops, this notification MUST NOT be
       sent to servers that themselves have triggered the
       notification."
  ::= { snmpTlstmNotifications 2 }
snmpTlstmServerInvalidCertificate13 NOTIFICATION-TYPE
  OBJECTS { snmpTlstmAddr13ServerFingerprint,
            snmpTlstmSessionInvalidServerCertificates}
  STATUS  current
  DESCRIPTION
      "Notification that the server certificate presented by an SNMP
       over TLS server could not be validated even if the
       fingerprint or expected validation path was known.  That is, a
       cryptographic validation error occurred during certificate
       validation processing.
       To avoid notification loops, this notification MUST NOT be
       sent to servers that themselves have triggered the
       notification."
  ::= { snmpTlstmNotifications 3 }
-- ************************************************
-- snmpTlstmCompliances - Conformance Information
-- ************************************************
snmpTlstmCompliances OBJECT IDENTIFIER ::= { snmpTlstmConformance 1 }
snmpTlstmGroups OBJECT IDENTIFIER ::= { snmpTlstmConformance 2 }
-- ************************************************
-- Compliance statements
-- ************************************************
snmpTlstmCompliance MODULE-COMPLIANCE
  STATUS      deprecated
  DESCRIPTION
      "The compliance statement for SNMP engines that support the
      SNMP-TLS-TM-MIB"
  MODULE
      MANDATORY-GROUPS { snmpTlstmStatsGroup,
                         snmpTlstmIncomingGroup,
                         snmpTlstmOutgoingGroup,
                         snmpTlstmNotificationGroup }
  ::= { snmpTlstmCompliances 1 }
snmpTlstmCompliance13 MODULE-COMPLIANCE
  STATUS      current
  DESCRIPTION
      "The compliance statement for SNMP engines that support the
      SNMP-TLS-TM-MIB"
  MODULE
      MANDATORY-GROUPS { snmpTlstmStatsGroup,
                         snmpTlstmIncoming13Group,
                         snmpTlstmOutgoing13Group,
                         snmpTlstmNotification13Group }
  ::= { snmpTlstmCompliances 2 }
-- ************************************************
-- Units of conformance
-- ************************************************
snmpTlstmStatsGroup OBJECT-GROUP
  OBJECTS {
      snmpTlstmSessionOpens,
      snmpTlstmSessionClientCloses,
      snmpTlstmSessionOpenErrors,
      snmpTlstmSessionAccepts,
      snmpTlstmSessionServerCloses,
      snmpTlstmSessionNoSessions,
      snmpTlstmSessionInvalidClientCertificates,
      snmpTlstmSessionUnknownServerCertificate,
      snmpTlstmSessionInvalidServerCertificates,
      snmpTlstmSessionInvalidCaches
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects for maintaining
      statistical information of an SNMP engine that
      implements the SNMP TLS Transport Model."
  ::= { snmpTlstmGroups 1 }
snmpTlstmIncomingGroup OBJECT-GROUP
  OBJECTS {
      snmpTlstmCertToTSNCount,
      snmpTlstmCertToTSNTableLastChanged,
      snmpTlstmCertToTSNFingerprint,
      snmpTlstmCertToTSNMapType,
      snmpTlstmCertToTSNData,
      snmpTlstmCertToTSNStorageType,
      snmpTlstmCertToTSNRowStatus
  }
  STATUS      deprecated
  DESCRIPTION
      "A collection of objects for maintaining
      incoming connection certificate mappings to
      tmSecurityNames of an SNMP engine that implements the
      SNMP TLS Transport Model."
  ::= { snmpTlstmGroups 2 }
snmpTlstmOutgoingGroup OBJECT-GROUP
  OBJECTS {
      snmpTlstmParamsCount,
      snmpTlstmParamsTableLastChanged,
      snmpTlstmParamsClientFingerprint,
      snmpTlstmParamsStorageType,
      snmpTlstmParamsRowStatus,
      snmpTlstmAddrCount,
      snmpTlstmAddrTableLastChanged,
      snmpTlstmAddrServerFingerprint,
      snmpTlstmAddrServerIdentity,
      snmpTlstmAddrStorageType,
      snmpTlstmAddrRowStatus
  }
  STATUS      deprecated
  DESCRIPTION
      "A collection of objects for maintaining
      outgoing connection certificates to use when opening
      connections as a result of SNMP-TARGET-MIB settings."
  ::= { snmpTlstmGroups 3 }
snmpTlstmNotificationGroup NOTIFICATION-GROUP
  NOTIFICATIONS {
      snmpTlstmServerCertificateUnknown,
      snmpTlstmServerInvalidCertificate
  }
  STATUS deprecated
  DESCRIPTION
      "Notifications"
  ::= { snmpTlstmGroups 4 }
snmpTlstmIncoming13Group OBJECT-GROUP
  OBJECTS {
      snmpTlstmCertToTSN13Count,
      snmpTlstmCertToTSN13TableLastChanged,
      snmpTlstmCertToTSN13Fingerprint,
      snmpTlstmCertToTSN13MapType,
      snmpTlstmCertToTSN13Data,
      snmpTlstmCertToTSN13StorageType,
      snmpTlstmCertToTSN13RowStatus
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects for maintaining
      incoming connection certificate mappings to
      tmSecurityNames of an SNMP engine that implements the
      SNMP TLS 1.3 Transport Model."
  ::= { snmpTlstmGroups 5 }
snmpTlstmOutgoing13Group OBJECT-GROUP
  OBJECTS {
      snmpTlstmParams13Count,
      snmpTlstmParams13TableLastChanged,
      snmpTlstmParams13ClientFingerprint,
      snmpTlstmParams13StorageType,
      snmpTlstmParams13RowStatus,
      snmpTlstmAddr13Count,
      snmpTlstmAddr13TableLastChanged,
      snmpTlstmAddr13ServerFingerprint,
      snmpTlstmAddr13ServerIdentity,
      snmpTlstmAddr13StorageType,
      snmpTlstmAddr13RowStatus
  }
  STATUS      current
  DESCRIPTION
      "A collection of objects for maintaining
      outgoing connection certificates to use when opening
      TLS 1.3 connections as a result of SNMP-TARGET-MIB settings."
  ::= { snmpTlstmGroups 6 }
snmpTlstmNotification13Group NOTIFICATION-GROUP
  NOTIFICATIONS {
      snmpTlstmServerCertificateUnknown,
      snmpTlstmServerInvalidCertificate13
  }
  STATUS current
  DESCRIPTION
      "Notifications for the SNMP TLS 1.3 Transport Model"
  ::= { snmpTlstmGroups 7 }
END


5. Security Considerations

This document updates a transport model that permits SNMP to utilize TLS security services. The security threats and how the TLS transport model mitigates these threats are covered throughout this document and in [RFC6353]. Security considerations for TLS are described in Section 10 and Appendix E of TLS 1.3 [RFC8446].

5.1. MIB Module Security

There are a number of management objects defined in this MIB module with a MAX-ACCESS clause of read-write and/or read-create. Such objects might be considered sensitive or vulnerable in some network environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations. These are the tables and objects and their sensitivity/vulnerability:

  • The snmpTlstmParams13Table can be used to change the outgoing X.509 certificate used to establish a TLS connection. Modifications to objects in this table need to be adequately authenticated since modifying the values in this table will have profound impacts to the security of outbound connections from the device. Since knowledge of authorization rules and certificate usage mechanisms might be considered sensitive, protection from disclosure of the SNMP traffic via encryption is automatically acheived via TLS 1.3.
  • The snmpTlstmAddr13Table can be used to change the expectations of the certificates presented by a remote TLS server. Modifications to objects in this table need to be adequately authenticated since modifying the values in this table will have profound impacts to the security of outbound connections from the device. Since knowledge of authorization rules and certificate usage mechanisms might be considered sensitive, protection from disclosure of the SNMP traffic via encryption is automatically acheived via TLS 1.3.
  • The snmpTlstmCertToTSN13Table is used to specify the mapping of incoming X.509 certificates to tmSecurityNames, which eventually get mapped to an SNMPv3 securityName. Modifications to objects in this table need to be adequately authenticated since modifying the values in this table will have profound impacts to the security of incoming connections to the device. Since knowledge of authorization rules and certificate usage mechanisms might be considered sensitive, protection from disclosure of the SNMP traffic via encryption is automatically acheived via TLS 1.3. When this table contains a significant number of rows it might affect the system performance when accepting new TLS connections.

Some of the readable objects in this MIB module (i.e., objects with a MAX-ACCESS other than not-accessible) might be considered sensitive or vulnerable in some network environments. It is thus important to control even GET and/or NOTIFY access to these objects and encrypt the values of these objects when sending them over the network via SNMP. These are the tables and objects and their sensitivity/vulnerability:

  • This MIB contains a collection of counters that monitor the TLS connections being established with a device. Since knowledge of connection and certificate usage mechanisms might be considered sensitive, protection from disclosure of the SNMP traffic via encryption is automatically acheived via TLS 1.3.

SNMP versions prior to SNMPv3 did not include adequate security. Even if the network itself is secure (for example, by using IPsec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB module.

As defined in Section 2.4, TLSTM clients and servers MUST NOT request, offer, or use SNMPv1 or SNMPv2c message processing described in [RFC3584], or the User-based Security Model of SNMPv3. Instead, it is RECOMMENDED to deploy SNMPv3 and to enable cryptographic security. It is then a customer/operator responsibility to ensure that the SNMP entity giving access to an instance of this MIB module is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them.

6. IANA Considerations

This document has no IANA actions beyond those performed as a part of [RFC6353].

7. Acknowledgements

Acknowledgements This document is based on [RFC6353]. This document was reviewed by the following people who helped provide useful comments: Michaela Vanderveen.

8. References

8.1. Normative References

[I-D.ietf-tls-dtls13]
Rescorla, E., Tschofenig, H., and N. Modadugu, "The Datagram Transport Layer Security (DTLS) Protocol Version 1.3", Work in Progress, Internet-Draft, draft-ietf-tls-dtls13-43, , <https://datatracker.ietf.org/doc/html/draft-ietf-tls-dtls13-43>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC3584]
Frye, R., Levi, D., Routhier, S., and B. Wijnen, "Coexistence between Version 1, Version 2, and Version 3 of the Internet-standard Network Management Framework", BCP 74, RFC 3584, DOI 10.17487/RFC3584, , <https://www.rfc-editor.org/info/rfc3584>.
[RFC5280]
Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, , <https://www.rfc-editor.org/info/rfc5280>.
[RFC5591]
Harrington, D. and W. Hardaker, "Transport Security Model for the Simple Network Management Protocol (SNMP)", STD 78, RFC 5591, DOI 10.17487/RFC5591, , <https://www.rfc-editor.org/info/rfc5591>.
[RFC6353]
Hardaker, W., "Transport Layer Security (TLS) Transport Model for the Simple Network Management Protocol (SNMP)", STD 78, RFC 6353, DOI 10.17487/RFC6353, , <https://www.rfc-editor.org/info/rfc6353>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/info/rfc8446>.
[STD62]
Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks", STD 62, RFC 3411, .
Case, J., Harrington, D., Presuhn, R., and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3412, .
Levi, D., Meyer, P., and B. Stewart, "Simple Network Management Protocol (SNMP) Applications", STD 62, RFC 3413, .
Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", STD 62, RFC 3414, .
Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3415, .
Presuhn, R., Ed., "Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3416, .
Presuhn, R., Ed., "Transport Mappings for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3417, .
Presuhn, R., Ed., "Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3418, .

8.2. Informative References

[RFC5246]
Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, , <https://www.rfc-editor.org/info/rfc5246>.
[STD58]
McCloghrie, K., Ed., Perkins, D., Ed., and J. Schoenwaelder, Ed., "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, .
McCloghrie, K., Ed., Perkins, D., Ed., and J. Schoenwaelder, Ed., "Textual Conventions for SMIv2", STD 58, RFC 2579, .
McCloghrie, K., Ed., Perkins, D., Ed., and J. Schoenwaelder, Ed., "Conformance Statements for SMIv2", STD 58, RFC 2580, .

Appendix A. Target and Notification Configuration Example

The following sections describe example configuration for the SNMP- TLS-TM-MIB, the SNMP-TARGET-MIB, the NOTIFICATION-MIB, and the SNMP- VIEW-BASED-ACM-MIB.

A.1. Configuring a Notification Originator

The following row adds the "Joe Cool" user to the "administrators" group:

    vacmSecurityModel              = 4 (TSM)
    vacmSecurityName               = "Joe Cool"
    vacmGroupName                  = "administrators"
    vacmSecurityToGroupStorageType = 3 (nonVolatile)
    vacmSecurityToGroupStatus      = 4 (createAndGo)

The following row configures the snmpTlstmAddr13Table to use certificate path validation and to require the remote notification receiver to present a certificate for the "server.example.org" identity.

    snmpTargetAddrName               =  "toNRAddr"
    snmpTlstmAddr13ServerFingerprint =  ""
    snmpTlstmAddr13ServerIdentity    =  "server.example.org"
    snmpTlstmAddr13StorageType       =  3         (nonVolatile)
    snmpTlstmAddr13RowStatus         =  4         (createAndGo)

The following row configures the snmpTargetAddrTable to send notifications using TLS/TCP to the snmptls-trap port at 192.0.2.1:

    snmpTargetAddrName              = "toNRAddr"
    snmpTargetAddrTDomain           = snmpTLSTCPDomain
    snmpTargetAddrTAddress          = "192.0.2.1:10162"
    snmpTargetAddrTimeout           = 1500
    snmpTargetAddrRetryCount        = 3
    snmpTargetAddrTagList           = "toNRTag"
    snmpTargetAddrParams            = "toNR"     (MUST match below)
    snmpTargetAddrStorageType       = 3          (nonVolatile)
    snmpTargetAddrRowStatus         = 4          (createAndGo)

The following row configures the snmpTargetParamsTable to send the notifications to "Joe Cool", using authPriv SNMPv3 notifications through the TransportSecurityModel [[RFC5591]]:

    snmpTargetParamsName            = "toNR"     (MUST match above)
    snmpTargetParamsMPModel         = 3 (SNMPv3)
    snmpTargetParamsSecurityModel   = 4 (TransportSecurityModel)
    snmpTargetParamsSecurityName    = "Joe Cool"
    snmpTargetParamsSecurityLevel   = 3          (authPriv)
    snmpTargetParamsStorageType     = 3          (nonVolatile)
    snmpTargetParamsRowStatus       = 4          (createAndGo)

A.2. Configuring TLSTM to Utilize a Simple Derivation of tmSecurityName

The following row configures the snmpTlstmCertToTSN13Table to map a validated client certificate, referenced by the client's public X.509 hash fingerprint, to a tmSecurityName using the subjectAltName component of the certificate.

    snmpTlstmCertToTSN13ID          = 1
                                    (chosen by ordering preference)
    snmpTlstmCertToTSN13Fingerprint = HASH (appropriate fingerprint)
    snmpTlstmCertToTSN13MapType     = snmpTlstmCertSANAny
    snmpTlstmCertToTSN13Data        = ""  (not used)
    snmpTlstmCertToTSN13StorageType = 3   (nonVolatile)
    snmpTlstmCertToTSN13RowStatus   = 4   (createAndGo)

This type of configuration should only be used when the naming conventions of the (possibly multiple) Certification Authorities are well understood, so two different principals cannot inadvertently be identified by the same derived tmSecurityName.

A.3. Configuring TLSTM to Utilize Table-Driven Certificate Mapping

The following row configures the snmpTlstmCertToTSN13Table to map a validated client certificate, referenced by the client's public X.509 hash fingerprint, to the directly specified tmSecurityName of "Joe Cool".

    snmpTlstmCertToTSN13ID           = 2
                                     (chosen by ordering preference)
    snmpTlstmCertToTSN13Fingerprint = HASH (appropriate fingerprint)
    snmpTlstmCertToTSN13MapType      = snmpTlstmCertSpecified
    snmpTlstmCertToTSN13SecurityName = "Joe Cool"
    snmpTlstmCertToTSN13StorageType  = 3  (nonVolatile)
    snmpTlstmCertToTSN13RowStatus    = 4  (createAndGo)

Author's Address

Kenneth Vaughn (editor)
Trevilon LLC
6606 FM 1488 RD
Suite 148-503
Magnolia, TX 77354
United States of America