Transport Layer Security Verion 1.3 (TLS 1.3) Transport Model for the
draft-vaughn-tlstm-update-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
|
|
|---|---|---|---|
| Author | Kenneth Vaughn | ||
| Last updated | 2021-03-29 | ||
| Replaced by | draft-ietf-opsawg-tlstm-update, draft-ietf-opsawg-tlstm-update, RFC 9456 | ||
| RFC stream | (None) | ||
| Formats | |||
| Additional resources | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-vaughn-tlstm-update-00
Internet Engineering Task Force K. Vaughn, Ed.
Internet-Draft Trevilon LLC
Obsoletes: 6353 (if approved) 29 March 2021
Intended status: Standards Track
Expires: 30 September 2021
Transport Layer Security Verion 1.3 (TLS 1.3) Transport Model for the
Simple Network Management Protocol Version 3 (SNMPv3)
draft-vaughn-tlstm-update-00
Abstract
describes a Transport Model for the Simple Network Management
Protocol Version 3 (SNMPv3) that uses Transport Layer Security
Version 1.3 (TLS 1.3). TLS 1.3 provides authentication and privacy
services for SNMPv3 applications. This document describes how the
TLS 1.3 Transport Model (TLSTM 1.3) implements the needed features of
an SNMPv3 Transport Subsystem to make this protection possible in an
interoperable way.
This Transport Model is designed to meet the security and operational
needs of network administrators. It supports the sending of SNMP
messages over TLS/TCP. TLS integrates well into existing public key
infrastructures.
This document also defines a portion of the Management Information
Base (MIB) for use with network management protocols. In particular,
it defines objects for managing TLSTM for SNMP.
This document obsoletes RFC 6353 (if approved).
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 30 September 2021.
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Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 6
1.2. Changes Since RFC 6353 . . . . . . . . . . . . . . . . . 7
2. The Transport Layer Security Protocol . . . . . . . . . . . . 8
3. How the TLSTM Fits into the Transport Subsystem . . . . . . . 9
3.1. Security Capabilities of This Model . . . . . . . . . . . 11
3.1.1. Threats . . . . . . . . . . . . . . . . . . . . . . . 11
3.1.2. Message Protection . . . . . . . . . . . . . . . . . 12
3.1.3. TLS Connections . . . . . . . . . . . . . . . . . . . 13
3.2. Security Parameter Passing . . . . . . . . . . . . . . . 13
3.3. Notifications and Proxy . . . . . . . . . . . . . . . . . 14
4. Elements of the Model . . . . . . . . . . . . . . . . . . . . 15
4.1. X.509 Certificates . . . . . . . . . . . . . . . . . . . 15
4.1.1. Provisioning for the Certificate . . . . . . . . . . 15
4.2. TLS Usage . . . . . . . . . . . . . . . . . . . . . . . . 17
4.3. SNMP Services . . . . . . . . . . . . . . . . . . . . . . 17
4.3.1. SNMP Services for an Outgoing Message . . . . . . . . 17
4.3.2. SNMP Services for an Incoming Message . . . . . . . . 18
4.4. Cached Information and References . . . . . . . . . . . . 19
4.4.1. TLS Transport Model Cached Information . . . . . . . 19
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4.4.1.1. tmSecurityName . . . . . . . . . . . . . . . . . 19
4.4.1.2. tmSessionID . . . . . . . . . . . . . . . . . . . 20
4.4.1.3. Session State . . . . . . . . . . . . . . . . . . 20
5. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 20
5.1. Procedures for an Incoming Message . . . . . . . . . . . 21
5.2. Procedures for an Outgoing SNMP Message . . . . . . . . . 22
5.3. Establishing or Accepting a Session . . . . . . . . . . . 24
5.3.1. Establishing a Session as a Client . . . . . . . . . 24
5.3.2. Accepting a Session as a Server . . . . . . . . . . . 26
5.4. Closing a Session . . . . . . . . . . . . . . . . . . . . 27
6. MIB Module Overview . . . . . . . . . . . . . . . . . . . . . 28
6.1. Structure of the MIB Module . . . . . . . . . . . . . . . 28
6.2. Textual Conventions . . . . . . . . . . . . . . . . . . . 28
6.3. Statistical Counters . . . . . . . . . . . . . . . . . . 28
6.4. Configuration Tables . . . . . . . . . . . . . . . . . . 28
6.4.1. Notifications . . . . . . . . . . . . . . . . . . . . 29
6.5. Relationship to Other MIB Modules . . . . . . . . . . . . 29
6.5.1. MIB Modules Required for IMPORTS . . . . . . . . . . 29
7. MIB Module Definition . . . . . . . . . . . . . . . . . . . . 29
8. Operational Considerations . . . . . . . . . . . . . . . . . 59
8.1. Sessions . . . . . . . . . . . . . . . . . . . . . . . . 60
8.2. Notification Receiver Credential Selection . . . . . . . 60
8.3. contextEngineID Discovery . . . . . . . . . . . . . . . . 61
8.4. Transport Considerations . . . . . . . . . . . . . . . . 61
9. Security Considerations . . . . . . . . . . . . . . . . . . . 61
9.1. Certificates, Authentication, and Authorization . . . . . 61
9.2. TLS Security Considerations . . . . . . . . . . . . . . . 62
9.2.1. TLS Version Requirements . . . . . . . . . . . . . . 62
9.2.2. Session Resumption . . . . . . . . . . . . . . . . . 63
9.2.3. TLS Ciphersuites, Extensions and Protocol
Invariants . . . . . . . . . . . . . . . . . . . . . 63
9.3. Use with SNMPv1/SNMPv2c Messages . . . . . . . . . . . . 63
9.4. MIB Module Security . . . . . . . . . . . . . . . . . . . 64
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 65
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 66
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 66
12.1. Normative References . . . . . . . . . . . . . . . . . . 66
12.2. Informative References . . . . . . . . . . . . . . . . . 68
Appendix A. Target and Notification Configuration Example . . . 68
A.1. Configuring a Notification Originator . . . . . . . . . . 68
A.2. Configuring TLSTM to Utilize a Simple Derivation of
tmSecurityName . . . . . . . . . . . . . . . . . . . . . 69
A.3. Configuring TLSTM to Utilize Table-Driven Certificate
Mapping . . . . . . . . . . . . . . . . . . . . . . . . . 70
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 70
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1. Introduction
It is important to understand the modular SNMPv3 architecture
(RFC3411) as enhanced by the Transport Subsystem [RFC5590]. It is
also important to understand the terminology of the SNMPv3
architecture in order to understand where the Transport Model
described in this document fits into the architecture and how it
interacts with the other architecture subsystems. For a detailed
overview of the documents that describe the current Internet-Standard
Management Framework, please refer to Section 7 of [RFC3410].
This document describes a Transport Model that makes use of Transport
Layer Security Version 1.3 (TLS 1.3) [RFC8446] within a Transport
Subsystem [RFC5590]. The Transport Model in this document is
referred to as the Transport Layer Security 1.3 Transport Model
(TLSTM 1.3). TLS employs the X.509 public key infrastructure
[RFC5280]. While TLS supports several authentication mechanisms,
this document only discusses X.509 certificate-based authentication.
This transport model is designed to meet the security and operational
needs of network administrators, operating in various environments
where data can be sent over a TCP-based stream. TLS integrates well
into existing public key infrastructures.
This document supports sending of SNMP messages over TLS/TCP. This
document also defines a portion of the Management Information Base
(MIB) for use with network management protocols. In particular, it
defines objects for managing the TLSTM 1.3. Managed objects are
accessed via a virtual information store, termed the Management
Information Base or MIB. MIB objects are generally accessed through
the Simple Network Management Protocol Version 3 (SNMPv3). Objects
in the MIB are defined using the mechanisms defined in the Structure
of Management Information (SMI). This memo specifies a MIB module
that is compliant to the SMIv2, which is described in [STD58].
The diagram shown below gives a conceptual overview of two SNMP
entities communicating using the TLS Transport Model (shown as
"TLSTM"). One entity contains a command responder and notification
originator application, and the other a command generator and
notification receiver application. This particular mix of
application types is an example only and other combinations are
equally valid.
Note: this diagram shows the Transport Security Model (TSM) being
used as the security model that is defined in [RFC5591].
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+-----------------------------------------------------------------+
| Network |
+-----------------------------------------------------------------+
^ | ^ |
|Notifications |Commands |Commands |Notifications
+---|-------------------|-------+ +--|--------------|-------------+
| | V | | | V |
| +----------+ +----------+ | | +----------+ +----------+ |
| | TLS | | TLS | | | | TLS | | TLS | |
| | (Client) | | (Server) | | | | (Client) | | (Server) | |
| +----------+ +----------+ | | +----------+ +----------+ |
| ^ ^ | | ^ ^ |
| | | | | | | |
| +------------+ | | +-------------+ |
| +----|-----------+ | | +-----|----------+ |
| | V | | | | V | |
| | +--------+ | +-----+ | | | +--------+ | +-----+ |
| | | TLS TM |<------>|Cache| | | | | TLS TM |<------>|Cache| |
| | +--------+ | +-----+ | | | +--------+ | +-----+ |
| |Transport Subsys| ^ | | |Transport Subsys| ^ |
| +----------------+ | | | +----------------+ | |
| ^ | | | ^ | |
| | +---+ | | | +---+ |
| v | | | V | |
| +-----+ +-------+ +------+ | | | +-----+ +-------+ +------+ | |
| | | |Message| |Sec. | | | | | | |Message| |Sec. | | |
| |Disp.| |Proc. | |Subsys| | | | |Disp.| |Proc. | |Subsys| | |
| | | |Subsys.| | | | | | | | |Subsys.| | | | |
| | | | | | | | | | | | | | | | | |
| | | |+----+ | |+---+ | | | | | | |+----+ | |+---+ | | |
| | <-->|v3MP|<-->|TSM|<--+ | | | <-->|v3MP|<-->|TSM|<--+ |
| | | |+----+ | |+---+ | | | | | |+----+ | |+---+ | |
| | | | | | | | | | | | | | | |
| +-----+ +-------+ +------+ | | +-----+ +-------+ +------+ |
| ^ | | ^ |
| | | | | |
| +-+------------+ | | +-+----------+ |
| | | | | | | |
| v v | | v V |
| +-----------+ +-------------+ | | +-----------+ +-------------+ |
| | COMMAND | | NOTIFICAT. | | | | COMMAND | | NOTIFICAT. | |
| | RESPONDER | | ORIGINATOR | | | | GENERATOR | | RECEIVER | |
| |application| | application | | | |application| | application | |
| +-----------+ +-------------+ | | +-----------+ +-------------+ |
| SNMP entity | | SNMP entity |
+-------------------------------+ +-------------------------------+
Figure 1: Two communicating SNMP entities using TLSTM
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1.1. Conventions
Within this document the terms "TLS", "SNMP", and "TLSTM" mean "TLS
1.3", "SMNPv3", and "TLSTM 1.3", respectively. The full forms of the
terms are generally 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.
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.
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.
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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 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].
1.2. Changes Since RFC 6353
This document obsoletes [RFC6353]. The changes from [RFC6353] are
noted as follows:
* Updating the fingerprint format to reflect the two-octet TLS 1.3
cipher suite identifier rather than the one-octet TLS 1.2 hash
algorithm identifier
* Deprecating the MIB tables that rely upon the original fingerprint
format and replacing them with similar tables using the updated
format
// Revising the existing tables appear to be problematic due to
the
// rules related to the RowStatus objects
* Limiting the discussion to TLS and removing any mention of DTLS
// The removal of DTLS from this document is proposed for several
// reasons, including: 1) CISA recommendations prefer the use of
TLS
// since it hides the identification of the encapsulated protocol
// completely whereas DTLS does not (i.e., DTLS does not encrypt
the
// UDP port number). 2) DTLS requires more logic /complexity to
// prevent replay and DoS attacks 3) Support for both TLS/TCP and
// DTLS/UDP implies additional testing requirements for little
// benefit 4) It seems likely that future versions of DTLS will
// frequently, if not always be released years after its companion
// TLS version; while this might not be the intent of the
developers
// of DTLS, the history of development cycles seem to suggest
// otherwise. Thus, even if there is a desire to support DTLS, it
// might be best to address the TLS TM and DTLS TM in separate
RFCs.
// 5) DTLS 1.3 is not yet an approved RFC. While it is currently
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// before the IESG, it seems premature to include within this
draft.
// 6) The main advantage of cited DTLS seems to be the shorter
// session setup time, which theoretically can be a benefit in
// certain network environments, but a. TLS1.3 already reduced
the
// setup time compared to TLS1.2, b. these environments are not
// typical of ITS deployments where network paths tend to be more
// direct and controlled and so the advantage of DTLS in this
sense
// is even smaller. 7) While most of ITS data is elemental and
well
// suited for traditional SNMP operations, several ITS devices
// support complex structures that are treated as a single element
// and are defined as a single SNMP object. As these can be 1500
// octets or more, a TCP environment is often needed anyway 8)
Within
// ITS, there has been at least one attempt to deploy a draft
version
// of DTLS 1.3 and the implementer decided to drop it and use TLS
1.3
// instead.
* Removing any defined support for SNMPv1 or SNMPv2c since these
would not be secure anyway
* Prohibiting the use of the User-based security model since this is
less secure
* Renegotiation of sessions is not supported as it is not supported
by TLS 1.3
* Prohibiting the use of the certificate's CommonName to determine a
tmSecurityName
* Prohibiting use of the 0-RTT mode of session resumption of TLS 1.3
* Forcing all SNMPv3 opertaions to use the highest security level
(authPriv) because all TLS 1.3 connections are authenticated and
encrypted.
2. The Transport Layer Security Protocol
TLS provides authentication, data message integrity, and privacy at
the transport layer.
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The primary goals of the TLS Transport Model are to provide peer
identity authentication, data integrity, and privacy between two
communicating SNMP entities. The TLS protocol provides a secure
transport upon which the TLSTM is based. Please refer to [RFC8446]
for a complete descriptions of the TLS.
3. How the TLSTM Fits into the Transport Subsystem
A transport model is a component of the Transport Subsystem. The TLS
Transport Model thus fits between the underlying TLS transport layer
and the Message Dispatcher RFC3411 component of the SNMP engine.
The TLS Transport Model will establish a session between itself and
the TLS Transport Model of another SNMP engine. The sending
transport model passes unencrypted and unauthenticated messages from
the Dispatcher to TLS to be encrypted and authenticated, and the
receiving transport model accepts decrypted and authenticated/
integrity-checked incoming messages from TLS and passes them to the
Dispatcher.
After a TLS Transport Model session is established, SNMP messages can
conceptually be sent through the session from one SNMP Message
Dispatcher to another SNMP Message Dispatcher. If multiple SNMP
messages are needed to be passed between two SNMP applications they
MAY be passed through the same session. A TLSTM implementation
engine MAY choose to close the session to conserve resources.
The TLS Transport Model of an SNMP engine will perform the
translation between TLS-specific security parameters and SNMP-
specific, model-independent parameters.
The diagram below depicts where the TLS Transport Model (shown as
"TLS TM") fits into the architecture described in RFC3411 and the
Transport Subsystem:
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+------------------------------+
| Network |
+------------------------------+
^ ^ ^
| | |
v v v
+------------------------------------------------------------------+
| +-------------------------------------------------+ |
| | Transport Subsystem | +--------+ |
| | +-------+ +-------+ +-------+ | | | |
| | | SSH | | TLS | . . . | other |<--->| Cache | |
| | | TM | | TM | | | | | | |
| | +-------+ +-------+ +-------+ | +--------+ |
| +-------------------------------------------------+ ^ |
| ^ | |
| | | |
| Dispatcher v | |
| +--------------+ +---------------------+ +---------------+ | |
| | Transport | | Message Processing | | Security | | |
| | Dispatcher | | Subsystem | | Subsystem | | |
| | | | +------------+ | | +-----------+ | | |
| | | | +->| v3MP |<--->| | Transport | | | |
| | Message | | | +------------+ | | | Security |<--+ |
| | Dispatcher <---->| | | | Model | | |
| | | | | | | +-----------+ | |
| | | | | | | +-----------+ | |
| | PDU Dispatch | | | +------------+ | | | Other | | |
| +--------------+ | +->| otherMP |<--->| | Model(s) | | |
| ^ | +------------+ | | +-----------+ | |
| | +---------------------+ +---------------+ |
| v |
| +-------+-------------------------+--------------+ |
| ^ ^ ^ |
| | | | |
| v v v |
| +-------------+ +---------+ +--------------+ +-------------+ |
| | COMMAND | | ACCESS | | NOTIFICATION | | PROXY | |
| | RESPONDER |<->| CONTROL |<->| ORIGINATOR | | FORWARDER | |
| | application | | | | applications | | application | |
| +-------------+ +---------+ +--------------+ +-------------+ |
| ^ ^ |
| | | |
| v v |
| +----------------------------------------------+ |
| | MIB instrumentation | SNMP entity |
+------------------------------------------------------------------+
Figure 2: TLS Transport Model and the SNMP Architecture
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3.1. Security Capabilities of This Model
3.1.1. Threats
The TLS Transport Model provides protection against the threats
identified by the RFC3411 architecture and other threats:
1. Modification of Information - The modification threat is the
danger that an unauthorized entity might alter in-transit SNMP
messages generated on behalf of an authorized principal in such a
way as to effect unauthorized management operations, including
falsifying the value of an object.
TLS provides integrity verification. In other words, TLS ensures
that the content of each received message has not been modified
during its transmission through the network, data has not been
altered or destroyed in an unauthorized manner, and data
sequences have not been altered or delayed to an extent greater
than can occur non-maliciously. This is achieved via message
authentication codes (MAC) for the handshake protocol and the TLS
cipher suites, which support integrity and confidentiality
protection for the record protocol.
2. Masquerade - The masquerade threat is the danger that management
operations unauthorized for a given principal might be attempted
by assuming the identity of another principal that has the
appropriate authorizations.
The TLSTM verifies the identity of the TLS server through the use
of the TLS protocol and X.509 certificates. A TLS Transport
Model implementation MUST support the authentication of both the
server and the client with X.509 certificates.
3. Replay - The replay threat is the danger that messages might be
maliciously resent in order to effect unauthorized management
operations.
TLS replay protection in the handshake protocol is achieved
through the server's random value and in the record protocol via
a new random number (nonce) for each record, with the nonce being
derived based on the record sequence number.
4. Disclosure - The disclosure threat is the danger of eavesdropping
on the exchanges between SNMP engines.
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TLS 1.3 provides protection against the disclosure of information
to unauthorized recipients or eavesdroppers by requiring
encryption of all traffic. TLS 1.3 cipher suites support
integrity and confidentiality protection for all TLS Transport
Model exchanges.
5. Key compromise - The key compromise attack consists of revealing
the secret long-term key(s) used to protect the data stream.
TLS 1.3 provides perfect forward secrecy. If these keys are
compromised after the TLS handshake completes, this does not
compromise the session key itself (see section E.1 of [RFC8446].
6. Denial of Service - The RFC3411 architecture states that denial-
of-service (DoS) attacks need not be addressed by an SNMP
security protocol.
The cookie mechanism of TLS might help mitigate this attack.
See Section 9 for more detail on the security considerations
associated with the TLSTM and these security threats.
3.1.2. Message Protection
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 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.
The TLS Transport Model determines from TLS the identity of the
authenticated principal, the transport type, and the transport
address associated with an incoming message. The TLS Transport Model
provides the identity and destination type and address to TLS for
outgoing messages.
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When an application requests a TLS Transport Model session for a
message, it SHOULD request a security level of authPriv. Regardless
of the security level requested, the TLS Transport Model MUST provide
authentication and privacy. How the security level is translated
into the algorithms used to provide data integrity and privacy is
implementation dependent.
The authentication, integrity, and privacy algorithms used by the TLS
protocol might vary over time as the science of cryptography
continues to evolve and the development of TLS continues over time.
Implementers are encouraged to plan for changes in operator trust of
particular algorithms.
3.1.3. TLS Connections
TLS connections are opened by the TLS Transport Model during the
elements of procedure for an outgoing SNMP message. Since the sender
of a message initiates the creation of a TLS connection if needed,
the TLS connection will already exist for an incoming message.
Implementations MAY choose to instantiate TLS connections in
anticipation of outgoing messages. This approach might be useful to
ensure that a TLS connection to a given target can be established
before it becomes important to send a message over the TLS
connection. Of course, there is no guarantee that a pre-established
session will still be valid when needed.
TLS connections over TCP sessions MUST provide a unique
tlstmSessionID for referencing the session; they do not require a
unique pairing of address and port attributes since TCP already
provides adequate session framing.
The tlstmSessionID MUST NOT change during the entire duration of the
session from the TLSTM's perspective, and MUST uniquely identify a
single session.
3.2. Security Parameter Passing
For the TLS server-side, TLS-specific security parameters (i.e.,
cipher_suites, X.509 certificate fields, IP addresses, and ports) are
translated by the TLS Transport Model into security parameters for
the TLS Transport Model and security model (e.g., tmSecurityLevel,
tmSecurityName, transportDomain, transportAddress). The transport-
related and TLS-security-related information, including the
authenticated identity, are stored in a cache referenced by
tmStateReference.
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For the TLS client side, the TLS Transport Model takes input provided
by the Dispatcher in the sendMessage() Abstract Service Interface
(ASI) and input from the tmStateReference cache. The TLS Transport
Model converts that information into suitable security parameters for
TLS and establishes sessions as needed.
The elements of procedure in Section 5 discuss these concepts in much
greater detail.
3.3. Notifications and Proxy
TLS connections might be initiated by TLS clients on behalf of SNMP
applications that initiate communications, such as command
generators, notification originators, proxy forwarders. Command
generators are frequently operated by a human, but notification
originators and proxy forwarders are usually unmanned automated
processes. The targets to whom notifications and proxied requests
are to be sent are typically determined and configured by a network
administrator.
The SNMP-TARGET-MIB module of RFC3413 contains objects for defining
management targets, including transportDomain, transportAddress,
securityName, securityModel, and securityLevel parameters, for
notification originator, proxy forwarder, and SNMP-controllable
command generator applications. Transport domains and transport
addresses are configured in the snmpTargetAddrTable, and the
securityModel, securityName, and securityLevel parameters are
configured in the snmpTargetParamsTable. This document defines a MIB
module that extends the SNMP-TARGET-MIB's snmpTargetParamsTable to
specify a TLS client-side certificate to use for the connection.
When configuring a TLS target, the snmpTargetAddrTDomain and
snmpTargetAddrTAddress parameters in snmpTargetAddrTable SHOULD be
set to the snmpTLSTCPDomain or snmpDTLSUDPDomain object and an
appropriate snmpTLSAddress value. When used with the SNMPv3 message
processing model, the snmpTargetParamsMPModel column of the
snmpTargetParamsTable SHOULD be set to a value of 3. The
snmpTargetParamsSecurityName SHOULD be set to an appropriate
securityName value, and the snmpTlstmParams13ClientFingerprint
parameter of the snmpTlstmParams13Table SHOULD be set to a value that
refers to a locally held certificate (and the corresponding private
key) to be used. Other parameters, for example, cryptographic
configuration such as which cipher_suites to use, MUST come from
configuration mechanisms not defined in this document.
The securityName defined in the snmpTargetParamsSecurityName column
will be used by the access control model to authorize any
notifications that need to be sent.
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4. Elements of the Model
This section contains definitions for the TLS Transport Model defined
by this document.
4.1. X.509 Certificates
TLS can make use of X.509 certificates for authentication of both
sides of the transport. This section discusses the use of X.509
certificates in the TLSTM.
While TLS supports several authentication mechanisms, this document
only discusses X.509-certificate-based authentication; other forms of
authentication are outside the scope of this specification. TLSTM
implementations are REQUIRED to support X.509 certificates.
4.1.1. Provisioning for the Certificate
Authentication using TLS requires that SNMP entities have
certificates, either signed by trusted Certification Authorities
(CAs), or self-signed. Furthermore, SNMP entities will most commonly
need to be provisioned with root certificates that represent the list
of trusted CAs that an SNMP entity can use for certificate
verification. SNMP entities SHOULD also be provisioned with an X.509
certificate revocation mechanism which can be used to verify that a
certificate has not been revoked. Trusted public keys from either CA
certificates and/or self-signed certificates MUST be installed into
the server through a trusted out-of-band mechanism and their
authenticity MUST be verified before access is granted.
Having received a certificate from a connecting TLSTM client, the
authenticated tmSecurityName of the principal is derived using the
snmpTlstmCertToTSN13Table. This table allows mapping of incoming
connections to tmSecurityNames through defined transformations. The
transformations defined in the SNMP-TLS-TM-MIB include:
* Mapping a certificate's subjectAltName component to a
tmSecurityName, or
* Mapping a certificate's fingerprint value to a directly specified
tmSecurityName
As an implementation hint: implementations MAY choose to discard any
connections for which no potential snmpTlstmCertToTSN13Table mapping
exists before performing certificate verification to avoid expending
computational resources associated with certificate verification.
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Deployments SHOULD map the "subjectAltName" component of X.509
certificates to the TLSTM specific tmSecurityNames. The
authenticated identity can be obtained by the TLS Transport Model by
extracting the subjectAltName(s) from the peer's certificate. The
receiving application will then have an appropriate tmSecurityName
for use by other SNMPv3 components like an access control model.
An example of this type of mapping setup can be found in Appendix A.
This tmSecurityName MAY be later translated from a TLSTM specific
tmSecurityName to an SNMP engine securityName by the security model.
A security model, like the TSM security model [RFC5591], MAY perform
an identity mapping or a more complex mapping to derive the
securityName from the tmSecurityName offered by the TLS Transport
Model.
The standard View-Based Access Control Model (VACM) (RFC3415)
constrains securityNames to be 32 octets or less in length. A TLSTM
generated tmSecurityName, possibly in combination with a messaging or
security model that increases the length of the securityName, might
cause the securityName length to exceed 32 octets. For example, a
32-octet tmSecurityName derived from an IPv6 address, paired with a
TSM prefix, will generate a 36-octet securityName. Such a
securityName will not be able to be used with standard VACM or TARGET
MIB modules. Operators SHOULD be careful to select algorithms and
subjectAltNames to avoid this situation.
A pictorial view of the complete transformation process (using the
TSM security model for the example) is shown below:
+-------------+ +-------+ +-----+
| Certificate | | | | |
| Path | | TLSTM | tmSecurityName | TSM |
| Validation | --> | | ----------------->| |
+-------------+ +-------+ +-----+
|
| securityName
V
+-------------+
| application |
+-------------+
Figure 3: TSM Securty Model Transformation Process
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4.2. TLS Usage
TLS MUST negotiate a cipher_suite that uses X.509 certificates for
authentication, and MUST authenticate both the client and the server.
The mandatory-to-implement cipher_suite is specified in the TLS
specification [RFC8446].
TLSTM verifies the certificates when the connection is opened (see
Section 5.3). TLS renegotiation is not supported with TLS 1.3, thus
there is no risk of a different certificate being used later in a TLS
session. MUST NOT be done.
4.3. SNMP Services
This section describes the services provided by the TLS Transport
Model with their inputs and outputs. The services are between the
Transport Model and the Dispatcher.
The services are described as primitives of an abstract service
interface (ASI) and the inputs and outputs are described as abstract
data elements as they are passed in these abstract service
primitives.
4.3.1. SNMP Services for an Outgoing Message
The Dispatcher passes the information to the TLS Transport Model
using the ASI defined in the Transport Subsystem:
statusInformation =
sendMessage(
IN destTransportDomain -- transport domain to be used
IN destTransportAddress -- transport address to be used
IN outgoingMessage -- the message to send
IN outgoingMessageLength -- its length
IN tmStateReference -- reference to transport state
)
The abstract data elements returned from or passed as parameters into
the abstract service primitives are as follows:
statusInformation: An indication of whether the sending of the
message was successful. If not, it is an
indication of the problem.
destTransportDomain: The transport domain for the associated
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destTransportAddress. The Transport Model uses
this parameter to determine the transport type of
the associated destTransportAddress. This
document specifies the snmpTLSTCPDomain transport
domain.
destTransportAddress: The transport address of the destination TLS
Transport Model in a format specified by the
SnmpTLSAddress TEXTUAL-CONVENTION.
outgoingMessage: The outgoing message to send to TLS for
encapsulation and transmission.
outgoingMessageLength: The length of the outgoingMessage.
tmStateReference: A reference used to pass model-specific and
mechanism-specific parameters between the
Transport Subsystem and transport-aware Security
Models.
4.3.2. SNMP Services for an Incoming Message
The TLS Transport Model processes the received message from the
network using the TLS service and then passes it to the Dispatcher
using the following ASI:
statusInformation =
receiveMessage(
IN transportDomain -- origin transport domain
IN transportAddress -- origin transport address
IN incomingMessage -- the message received
IN incomingMessageLength -- its length
IN tmStateReference -- reference to transport state
)
The abstract data elements returned from or passed as parameters into
the abstract service primitives are as follows:
statusInformation: An indication of whether the passing of the
message was successful. If not, it is an
indication of the problem.
transportDomain: The transport domain for the associated
transportAddress. This document specifies the
snmpTLSTCPDomain transport domain.
transportAddress: The transport address of the source of the
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received message in a format specified by the
SnmpTLSAddress TEXTUAL-CONVENTION.
incomingMessage: The whole SNMP message after being processed by
TLS.
incomingMessageLength: The length of the incomingMessage.
tmStateReference: A reference used to pass model-specific and
mechanism-specific parameters between the
Transport Subsystem and transport-aware Security
Models.
4.4. Cached Information and References
When performing SNMP processing, there are two levels of state
information that might need to be retained: the immediate state
linking a request-response pair, and potentially longer-term state
relating to transport and security. "Transport Subsystem for the
Simple Network Management Protocol (SNMP)" [RFC5590] defines general
requirements for caches and references.
4.4.1. TLS Transport Model Cached Information
The TLS Transport Model has specific responsibilities regarding the
cached information. See the Elements of Procedure in Section 5 for
detailed processing instructions on the use of the tmStateReference
fields by the TLS Transport Model.
4.4.1.1. tmSecurityName
The tmSecurityName MUST be a human-readable name (in SnmpAdminString
format as defined in RFC3411) representing the identity that has been
set according to the procedures in Section 5. The tmSecurityName
MUST be constant for all traffic passing through a single TLSTM
session. Messages MUST NOT be sent through an existing TLS
connection that was established using a different tmSecurityName.
On the TLS server side of a connection, the tmSecurityName is derived
using the procedures described in Section 5.3.2 and the SNMP- TLS-TM-
MIB's snmpTlstmCertToTSN13Table DESCRIPTION clause.
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On the TLS client side of a connection, the tmSecurityName is
presented to the TLS Transport Model by the security model through
the tmStateReference. This tmSecurityName is typically a copy of or
is derived from the securityName that was passed by application
(possibly because of configuration specified in the SNMP-TARGET-MIB).
The Security Model likely derived the tmSecurityName from the
securityName presented to the Security Model by the application
(possibly because of configuration specified in the SNMP-TARGET-MIB).
Transport-Model-aware security models derive tmSecurityName from a
securityName, possibly configured in MIB modules for notifications
and access controls. Transport Models SHOULD use predictable
tmSecurityNames so operators will know what to use when configuring
MIB modules that use securityNames derived from tmSecurityNames. The
TLSTM generates predictable tmSecurityNames based on the
configuration found in the SNMP-TLS-TM-MIB's
snmpTlstmCertToTSN13Table and relies on the network operators to have
configured this table appropriately.
4.4.1.2. tmSessionID
The tmSessionID MUST be recorded per message at the time of receipt.
When tmSameSecurity is set, the recorded tmSessionID can be used to
determine whether the TLS connection available for sending a
corresponding outgoing message is the same TLS connection as was used
when receiving the incoming message (e.g., a response to a request).
4.4.1.3. Session State
The per-session state that is referenced by tmStateReference MAY be
saved across multiple messages in a Local Configuration Datastore.
Additional session/connection state information might also be stored
in a Local Configuration Datastore (LCD).
5. Elements of Procedure
Abstract service interfaces have been defined by RFC3411 and further
augmented by [RFC5590] to describe the conceptual data flows between
the various subsystems within an SNMP entity. The TLSTM uses some of
these conceptual data flows when communicating between subsystems.
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To simplify the elements of procedure, the release of state
information is not always explicitly specified. As a general rule,
if state information is available when a message gets discarded, the
message-state information SHOULD also be released. If state
information is available when a session is closed, the session state
information SHOULD also be released. Sensitive information, like
cryptographic keys, SHOULD be overwritten appropriately prior to
being released.
An error indication in statusInformation will typically include the
Object Identifier (OID) and value for an incremented error counter.
This MAY be accompanied by the requested securityLevel and the
tmStateReference. Per-message context information is not accessible
to Transport Models, so for the returned counter OID and value,
contextEngine would be set to the local value of snmpEngineID and
contextName to the default context for error counters.
5.1. Procedures for an Incoming Message
This section describes the procedures followed by the TLS Transport
Model when it receives a TLS protected packet. It describes the
transport processing REQUIRED once the TLS processing has been
completed.
The procedures in this section describe how the TLS Transport Model
is to process messages that have already been properly extracted from
the TLS stream. Implementations SHOULD verify that messages from TLS
are complete and single. For example, partial SNMP messages can be
received from a TLS stream. These steps describe the processing of a
singular SNMP message after it has been delivered from the TLS
stream.
1) Determine the tlstmSessionID for the incoming message. The
tlstmSessionID MUST be a unique session identifier for this TLS
connection. The contents and format of this identifier are
implementation dependent as long as it is unique to the session.
A session identifier MUST NOT be reused until all references to
it are no longer in use. The tmSessionID is equal to the
tlstmSessionID. tmSessionID refers to the session identifier when
stored in the tmStateReference and tlstmSessionID refers to the
session identifier when stored in the LCD. They MUST always be
equal when processing a given session's traffic.
If this is the first message received through this session, and
the session does not have an assigned tlstmSessionID yet, then
the snmpTlstmSessionAccepts counter is incremented and a
tlstmSessionID for the session is created. This will only happen
on the server side of a connection because a client would have
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already assigned a tlstmSessionID during the openSession()
invocation. Implementations MAY have performed the procedures
described in Section 5.3.2 prior to this point or they MAY
perform them now, but the procedures described in Section 5.3.2
MUST be performed before continuing beyond this point.
2) Create a tmStateReference cache for the subsequent reference and
assign the following values within it:
tmTransportDomain snmpTLSTCPDomain.
tmTransportAddress The address from which the message
originated.
tmSecurityLevel The tmSecurityLevel for the session, as
discussed in Sections 3.1.2 and 5.3, which will
always be authPriv for TLS 1.3.
tmSecurityName The derived tmSecurityName for the session as
discussed in Section 5.3. This value MUST be
constant during the lifetime of the session.
tmSessionID The tlstmSessionID described in step 1 above.
3) The incomingMessage and incomingMessageLength are assigned values
from the TLS processing.
4) The TLS Transport Model passes the transportDomain,
transportAddress, incomingMessage, and incomingMessageLength to
the Dispatcher using the receiveMessage ASI:
statusInformation =
receiveMessage(
IN transportDomain -- snmpTLSTCPDomain,
IN transportAddress -- address for the received message
IN incomingMessage -- the whole SNMP message from TLS
IN incomingMessageLength -- the length of the SNMP message
IN tmStateReference -- transport info
)
5.2. Procedures for an Outgoing SNMP Message
The Dispatcher sends a message to the TLS Transport Model using the
following ASI:
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statusInformation =
sendMessage(
IN destTransportDomain -- transport domain to be used
IN destTransportAddress -- transport address to be used
IN outgoingMessage -- the message to send
IN outgoingMessageLength -- its length
IN tmStateReference -- transport info
)
This section describes the procedure followed by the TLS Transport
Model whenever it is requested through this ASI to send a message.
1) If tmStateReference does not refer to a cache containing values
for tmTransportDomain, tmTransportAddress, tmSecurityName, and
tmSameSecurity, then increment the snmpTlstmSessionInvalidCaches
counter, discard the message, and return the error indication in
the statusInformation. Processing of this message stops.
2) Extract the tmSessionID, tmTransportDomain, tmTransportAddress,
tmSecurityName, and tmSameSecurity values from the
tmStateReference. Note: the tmSessionID value might be undefined
if no session exists yet over which the message can be sent.
3) If tmSameSecurity is true and tmSessionID is either undefined or
refers to a session that is no longer open, then increment the
snmpTlstmSessionNoSessions counter, discard the message, and
return the error indication in the statusInformation. Processing
of this message stops.
4) If tmSameSecurity is false and tmSessionID refers to a session
that is no longer available, then an implementation SHOULD open a
new session, using the openSession() ASI (described in greater
detail in step 5b). Instead of opening a new session an
implementation MAY return an snmpTlstmSessionNoSessions error to
the calling module and stop the processing of the message.
5) If tmSessionID is undefined, then use tmTransportDomain,
tmTransportAddress, and tmSecurityName to see if there is a
corresponding entry in the LCD suitable to send the message over.
5a) If there is a corresponding LCD entry, then this session
will be used to send the message.
5b) If there is no corresponding LCD entry, then open a session
using the openSession() ASI (discussed further in
Section 5.3.1). Implementations MAY wish to offer message
buffering to prevent redundant openSession() calls for the
same cache entry. If an error is returned from
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openSession(), then discard the message, discard the
tmStateReference, increment the snmpTlstmSessionOpenErrors,
return an error indication to the calling module, and stop
the processing of the message.
6) Using either the session indicated by the tmSessionID (if there
was one) or the session resulting from a previous step (4 or 5),
pass the outgoingMessage to TLS for encapsulation and
transmission.
5.3. Establishing or Accepting a Session
Establishing a TLS connection as either a client or a server requires
slightly different processing. The following two sections describe
the necessary processing steps.
5.3.1. Establishing a Session as a Client
The TLS Transport Model provides the following primitive for use by a
client to establish a new TLS connection:
statusInformation = -- errorIndication or success
openSession(
IN tmStateReference -- transport information to be used
OUT tmStateReference -- transport information to be used
IN maxMessageSize -- of the sending SNMP entity
)
The following describes the procedure to follow when establishing an
SNMP over a TLS connection between SNMP engines for exchanging SNMP
messages. This process is followed by any SNMP client's engine when
establishing a session for subsequent use.
This procedure MAY be done automatically for an SNMP application that
initiates a transaction, such as a command generator, a notification
originator, or a proxy forwarder.
1) The snmpTlstmSessionOpens counter is incremented.
2) The client selects the appropriate certificate and cipher_suites
for the key agreement based on the tmSecurityName for the
session. For sessions being established as a result of an SNMP-
TARGET-MIB based operation, the certificate will potentially have
been identified via the snmpTlstmParams13Table mapping and the
cipher_suites will have to be taken from a system-wide or
implementation-specific configuration. If no row in the
snmpTlstmParams13Table exists, then implementations MAY choose to
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establish the connection using a default client certificate
available to the application. Otherwise, the certificate and
appropriate cipher_suites will need to be passed to the
openSession() ASI as supplemental information or configured
through an implementation-dependent mechanism. The security
level of the session MUST always be authPriv and is reported in
the tmStateReference cache as tmSecurityLevel. For TLS to
provide strong authentication, each principal acting as a command
generator SHOULD have its own certificate.
3) Using the destTransportDomain and destTransportAddress values,
the client will initiate the TLS handshake protocol to establish
a session key for message integrity and encryption. Note that
with TLS 1.3, only one key is necessary to accomplish both
message integrity and encryption.
If the attempt to establish a session is unsuccessful, then
snmpTlstmSessionOpenErrors is incremented, an error indication is
returned, and processing stops. If the session failed to open
because the presented server certificate was unknown or invalid,
then the snmpTlstmSessionUnknownServerCertificate or
snmpTlstmSessionInvalidServerCertificates MUST be incremented and
an snmpTlstmServerCertificateUnknown or
snmpTlstmServerInvalidCertificate13 notification SHOULD be sent
as appropriate. Reasons for server certificate invalidation
include, but are not limited to, cryptographic validation
failures and an unexpected presented certificate identity.
4) The TLS client MUST then verify that the TLS server's presented
certificate is the expected certificate. The TLS client MUST NOT
transmit SNMP messages until the server certificate has been
authenticated, the client certificate has been transmitted, and
the TLS connection has been fully established.
If the connection is being established from a configuration based
on SNMP-TARGET-MIB configuration, then the
snmpTlstmAddr13Table DESCRIPTION clause describes how the
verification is done (using either a certificate fingerprint, or
an identity authenticated via certification path validation).
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If the connection is being established for reasons other than
configuration found in the SNMP-TARGET-MIB, then configuration
and procedures outside the scope of this document SHOULD be
followed. Configuration mechanisms SHOULD be similar in nature
to those defined in the snmpTlstmAddr13Table to ensure
consistency across management configuration systems. For
example, a command- line tool for generating SNMP GETs might
support specifying either the server's certificate fingerprint or
the expected host name as a command-line argument.
5) TLS provides assurance that the authenticated identity in the
certificate has been signed by a trusted configured Certification
Authority. If verification of the server's certificate fails in
any way (for example, because of failures in cryptographic
verification or the presented identity did not match the expected
named entity), then the session establishment MUST fail, and the
snmpTlstmSessionInvalidServerCertificates object is incremented.
If the session cannot be opened for any reason at all, including
cryptographic verification failures and
snmpTlstmCertToTSN13Table lookup failures, then the
snmpTlstmSessionOpenErrors counter is incremented and processing
stops.
6) The TLSTM-specific session identifier (tlstmSessionID) is set in
the tmSessionID of the tmStateReference passed to the TLS
Transport Model to indicate that the session has been established
successfully and to point to a specific TLS connection for future
use. The tlstmSessionID is also stored in the LCD for later
lookup during processing of incoming messages (Section 5.1).
5.3.2. Accepting a Session as a Server
A TLS server SHOULD accept new session connections from any client
for which it is able to verify the client's credentials. This is
done by authenticating the client's presented certificate through a
certificate path validation process (e.g., [RFC5280]) or through
certificate fingerprint verification using fingerprints configured in
the snmpTlstmCertToTSN13Table. Afterward, the server will determine
the identity of the remote entity using the following procedures.
The TLS server identifies the authenticated identity from the TLS
client's principal certificate using configuration information from
the snmpTlstmCertToTSN13Table mapping table. The TLS server MUST
request and expect a certificate from the client and MUST NOT accept
SNMP messages over the TLS connection until the client has sent a
certificate and it has been authenticated. The resulting derived
tmSecurityName is recorded in the tmStateReference cache as
tmSecurityName. The details of the lookup process are fully
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described in the DESCRIPTION clause of the
snmpTlstmCertToTSN13Table MIB object. If any verification fails in
any way (for example, because of failures in cryptographic
verification or because of the lack of an appropriate row in the
snmpTlstmCertToTSN13Table), then the session establishment MUST fail,
and the snmpTlstmSessionInvalidClientCertificates object is
incremented. If the session cannot be opened for any reason at all,
including cryptographic verification failures, then the
snmpTlstmSessionOpenErrors counter is incremented and processing
stops.
Servers that wish to support multiple principals at a particular port
SHOULD make use of a TLS extension that allows server-side principal
selection like the Server Name Indication extension defined in
Section 3 of [RFC6066]. Supporting this will allow, for example,
sending notifications to a specific principal at a given TCP port.
5.4. Closing a Session
The TLS Transport Model provides the following primitive to close a
session:
statusInformation =
closeSession(
IN tmSessionID -- session ID of the session to be closed
)
The following describes the procedure to follow to close a session
between a client and server. This process is followed by any SNMP
engine closing the corresponding SNMP session.
1) Increment either the snmpTlstmSessionClientCloses or the
snmpTlstmSessionServerCloses counter as appropriate.
2) Look up the session using the tmSessionID.
3) If there is no open session associated with the tmSessionID, then
closeSession processing is completed.
4) Have TLS close the specified connection. This MUST include
sending a close_notify TLS Alert to inform the other side that
session cleanup might be performed.
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6. MIB Module Overview
This MIB module provides management of the TLS Transport Model. It
defines needed textual conventions, statistical counters,
notifications, and configuration infrastructure necessary for session
establishment. Example usage of the configuration tables can be
found in Appendix A.
6.1. Structure of the MIB Module
Objects in this MIB module are arranged into subtrees. Each subtree
is organized as a set of related objects. The overall structure and
assignment of objects to their subtrees, and the intended purpose of
each subtree, is shown below.
6.2. Textual Conventions
Generic and Common Textual Conventions used in this module can be
found summarized at http://www.ops.ietf.org/mib-common-tcs.html.
This module defines the following Textual Conventions:
* A new TransportAddress format for describing TLS connection
addressing requirements.
* A certificate fingerprint allowing MIB module objects to
generically refer to a stored X.509 certificate using a
cryptographic hash as a reference pointer.
6.3. Statistical Counters
The SNMP-TLS-TM-MIB defines counters that provide network management
stations with information about session usage and potential errors
that a device might be experiencing.
6.4. Configuration Tables
The SNMP-TLS-TM-MIB defines configuration tables that an
administrator can use for configuring a device for sending and
receiving SNMP messages over TLS. In particular, there are MIB
tables that extend the SNMP-TARGET-MIB for configuring TLS
certificate usage and a MIB table for mapping incoming TLS client
certificates to SNMPv3 tmSecurityNames.
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6.4.1. Notifications
The SNMP-TLS-TM-MIB defines notifications to alert management
stations when a TLS connection fails because a server's presented
certificate did not meet an expected value
(snmpTlstmServerCertificateUnknown) or because cryptographic
validation failed (snmpTlstmServerInvalidCertificate13).
6.5. Relationship to Other MIB Modules
Some management objects defined in other MIB modules are applicable
to an entity implementing the TLS Transport Model. In particular, it
is assumed that an entity implementing the SNMP-TLS-TM-MIB will
implement the SNMPv2-MIB (RFC3418), the SNMP-FRAMEWORK-MIB (RFC3411),
the SNMP-TARGET-MIB (RFC3413), the SNMP-NOTIFICATION-MIB (RFC3413),
and the SNMP-VIEW-BASED-ACM-MIB (RFC3415).
The SNMP-TLS-TM-MIB module contained in this document is for managing
TLS Transport Model information.
6.5.1. MIB Modules Required for IMPORTS
The SNMP-TLS-TM-MIB module imports items from SNMPv2-SMI (RFC2578),
SNMPv2-TC (RFC2579), SNMP-FRAMEWORK-MIB (RFC3411), SNMP-TARGET-MIB
(RFC3413), and SNMPv2-CONF (RFC2580).
7. 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 "202103280000Z"
ORGANIZATION "ISMS Working Group"
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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 "202103280000Z"
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 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
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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
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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/
"
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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."
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::= { 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
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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."
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::= { 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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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"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
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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,
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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,
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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
8. Operational Considerations
This section discusses various operational aspects of deploying
TLSTM.
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8.1. Sessions
Within this document, the term "session" means a security association
between two TLSTM instances. State information for the sessions are
maintained in each TLSTM implementation and this information is
created and destroyed as sessions are opened and closed. A "broken"
session (one side up and one side down) can result if one side of a
session is brought down abruptly (i.e., reboot, power outage, etc.).
Whenever possible, implementations SHOULD provide graceful session
termination through the use of TLS closure alert or error alert
messages. Implementations SHOULD also have a system in place for
detecting "broken" sessions.
Implementations SHOULD limit the lifetime of established sessions
depending on the algorithms used for generation of the master session
secret, the privacy and integrity algorithms used to protect
messages, the environment of the session, the amount of data
transferred, and the sensitivity of the data.
TLS1.3 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.
8.2. Notification Receiver Credential Selection
When an SNMP engine needs to establish an outgoing session for
notifications, the snmpTargetParamsTable includes an entry for the
snmpTargetParamsSecurityName of the target. Servers that wish to
support multiple principals at a particular port SHOULD make use of
the Server Name Indication extension defined in Section 3 of
[RFC6066]. Without the Server Name Indication the receiving SNMP
engine (server) will not know which TLS certificate to offer to the
client so that the tmSecurityName identity-authentication will be
successful.
Another solution is to maintain a one-to-one mapping between
certificates and incoming ports for notification receivers. This can
be handled at the notification originator by configuring the
snmpTargetAddrTable (snmpTargetAddrTDomain and
snmpTargetAddrTAddress) and requiring the receiving SNMP engine to
monitor multiple incoming static ports based on which principals are
capable of receiving notifications.
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Implementations MAY also choose to designate a single Notification
Receiver Principal to receive all incoming notifications or select an
implementation specific method of selecting a server certificate to
present to clients.
8.3. contextEngineID Discovery
SNMPv3 requires that an application know the identifier
(snmpEngineID) of the remote SNMP protocol engine in order to
retrieve or manipulate objects maintained on the remote SNMP entity.
[RFC5343] introduces a well-known localEngineID and a discovery
mechanism that can be used to learn the snmpEngineID of a remote SNMP
protocol engine. Implementations are RECOMMENDED to support and use
the contextEngineID discovery mechanism defined in [RFC5343].
8.4. Transport Considerations
This document defines how SNMP messages can be transmitted over TLS,
which is based on TCP. Transport over DTLS and underlying UDP has
been removed to further enhance security and due to the diminishing
returns on the session setup efficiencies, since TLS 1.3 saves one
roundtrip compared to TLS 1.2.
TLS has operational considerations that SHOULD be taken into
consideration with respect to MTU size, performance, etc.
9. Security Considerations
This document describes 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. Security considerations for TLS are described in
Section 10 and Appendix E of TLS 1.3 [RFC8446].
9.1. Certificates, Authentication, and Authorization
Implementations are responsible for providing a security certificate
installation and configuration mechanism. Implementations SHOULD
support certificate revocation lists.
TLS provides for authentication of the identity of both the TLS
server and the TLS client. Access to MIB objects for the
authenticated principal MUST be enforced by an access control
subsystem (e.g., the VACM).
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Authentication of the command generator principal's identity is
important for use with the SNMP access control subsystem to ensure
that only authorized principals have access to potentially sensitive
data. The authenticated identity of the command generator
principal's certificate is mapped to an SNMP model-independent
securityName for use with SNMP access control.
The TLS handshake only provides assurance that the certificate of the
authenticated identity has been signed by a configured trusted
Certification Authority. TLS has no way to further authorize or
reject access based on the authenticated identity. An Access Control
Model (such as the VACM) provides access control and authorization of
a command generator's requests to a command responder and a
notification receiver's authorization to receive Notifications from a
notification originator. However, to avoid man-in-the-middle
attacks, both ends of the TLS-based connection MUST check the
certificate presented by the other side against what was expected.
For example, command generators are to check that the command
responder presented and authenticated itself with an X.509
certificate that was expected. Not doing so would allow an impostor,
at a minimum, to present false data, receive sensitive information,
and/or provide a false belief that configuration was actually
received and acted upon. Authenticating and verifying the identity
of the TLS server and the TLS client for all operations ensures the
authenticity of the SNMP engine that provides MIB data.
The instructions found in the DESCRIPTION clause of the
snmpTlstmCertToTSN13Table object MUST be followed exactly. It is
also important that the rows of the table be searched in prioritized
order starting with the row containing the lowest numbered
snmpTlstmCertToTSN13ID value.
9.2. TLS Security Considerations
This section discusses security considerations specific to the usage
of TLS.
9.2.1. TLS Version Requirements
Implementations of TLS typically support multiple versions of the
Transport Layer Security protocol as well as the older Secure Sockets
Layer (SSL) protocol. Because of known security vulnerabilities,
TLSTM clients and servers MUST NOT request, offer, or use SSL 2.0 or
3.0, or TLS 1.0 or 1.1. See Appendix D.5 of [RFC8446] for further
details. For backward compatibility issues with older TLS versions,
see Appendix D of [RFC8446].
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9.2.2. Session Resumption
TLS TM clients and servers MUST NOT request, offer or use the 0-RTT
mode of TLS1.3. [RFC8446] removed the renegotiation supported in
TLS1.2 [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.
9.2.3. 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.
9.3. Use with SNMPv1/SNMPv2c Messages
The SNMPv1 and SNMPv2c message processing described in [RFC3584] (BCP
74) always selects the SNMPv1 or SNMPv2c Security Models,
respectively. Both of these and the User-based Security Model of
SNMPv3 derive the securityName and securityLevel from the SNMP
message received, even when the message was received over a secure
transport. Access control decisions are therefore made based on the
contents of the SNMP message, rather than using the authenticated
identity and securityLevel provided by the TLS Transport Model.
Implementations MUST only send SNMPv3 messages using the Transport
Security Model (TSM) or another secure-transport aware security model
over the TLSTM transport.
Implementations MUST NOT use a non-transport-aware Security Model
(e.g., SNMPv1, SNMPv2c, or the User-based Security Model of SNMPv3)
with a secure Transport Model.
It is RECOMMENDED that deployments that support the TLSTM disable or
not support previous versions of SNMP or the User-based Security
Model of SNMPv3.
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9.4. 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:
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* 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.
It is RECOMMENDED that implementers consider the security features as
provided by the SNMPv3 framework (see Section 8 of [RFC3410]),
including full support for the SNMPv3 cryptographic mechanisms (for
authentication and privacy).
Further, deployment of SNMP versions prior to SNMPv3 is NOT
RECOMMENDED. 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.
10. IANA Considerations
IANA has assigned:
1. Two TCP/UDP port numbers from the "Registered Ports" range of the
Port Numbers registry, with the following keywords:
Keyword Decimal Description References
------- ------- ----------- ----------
snmptls 10161/tcp SNMP-TLS [RFC6353]
snmptls-trap 10162/tcp SNMP-Trap-TLS [RFC6353]
These are the default ports for receipt of SNMP command messages
(snmptls and snmpdtls) and SNMP notification messages (snmptls-trap
and snmpdtls-trap) over a TLS Transport Model as defined in this
document.
1. An SMI number (8) under snmpDomains for the snmpTLSTCPDomain
object identifier
2. An SMI number (198) under mib-2, for the MIB module in this
document
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3. "tls" as the corresponding prefix for the snmpTLSTCPDomain in the
SNMP Transport Domains registry
11. Acknowledgements
This document is based on [RFC6353].
This document was reviewed by the following people who helped provide
useful comments (in alphabetical order): Michaela Vanderveen.
Work to develop and review this document was supported in part by the
United States Department of Transportation.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<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, August 2003,
<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, May 2008,
<https://www.rfc-editor.org/info/rfc5280>.
[RFC5590] Harrington, D. and J. Schoenwaelder, "Transport Subsystem
for the Simple Network Management Protocol (SNMP)",
STD 78, RFC 5590, DOI 10.17487/RFC5590, June 2009,
<https://www.rfc-editor.org/info/rfc5590>.
[RFC5591] Harrington, D. and W. Hardaker, "Transport Security Model
for the Simple Network Management Protocol (SNMP)",
STD 78, RFC 5591, DOI 10.17487/RFC5591, June 2009,
<https://www.rfc-editor.org/info/rfc5591>.
[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
Extensions: Extension Definitions", RFC 6066,
DOI 10.17487/RFC6066, January 2011,
<https://www.rfc-editor.org/info/rfc6066>.
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[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[STD58] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, April 1999.
McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Conformance Statements for SMIv2",
STD 58, RFC 2580, April 1999.
[STD62] Harrington, D., Presuhn, R., and B. Wijnen, "An
Architecture for Describing Simple Network Management
Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
December 2002.
Case, J., Harrington, D., Presuhn, R., and B. Wijnen,
"Message Processing and Dispatching for the Simple Network
Management Protocol (SNMP)", STD 62, RFC 3412, December
2002.
Levi, D., Meyer, P., and B. Stewart, "Simple Network
Management Protocol (SNMP) Applications", STD 62,
RFC 3413, December 2002.
Blumenthal, U. and B. Wijnen, "User-based Security Model
(USM) for version 3 of the Simple Network Management
Protocol (SNMPv3)", STD 62, RFC 3414, December 2002.
Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
Management Protocol (SNMP)", STD 62, RFC 3415, December
2002.
Presuhn, R., Ed., "Version 2 of the Protocol Operations
for the Simple Network Management Protocol (SNMP)",
STD 62, RFC 3416, December 2002.
Presuhn, R., Ed., "Transport Mappings for the Simple
Network Management Protocol (SNMP)", STD 62, RFC 3417,
December 2002.
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Presuhn, R., Ed., "Management Information Base (MIB) for
the Simple Network Management Protocol (SNMP)", STD 62,
RFC 3418, December 2002.
12.2. Informative References
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410,
DOI 10.17487/RFC3410, December 2002,
<https://www.rfc-editor.org/info/rfc3410>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/info/rfc5246>.
[RFC5343] Schoenwaelder, J., "Simple Network Management Protocol
(SNMP) Context EngineID Discovery", STD 78, RFC 5343,
DOI 10.17487/RFC5343, September 2008,
<https://www.rfc-editor.org/info/rfc5343>.
[RFC6353] Hardaker, W., "Transport Layer Security (TLS) Transport
Model for the Simple Network Management Protocol (SNMP)",
STD 78, RFC 6353, DOI 10.17487/RFC6353, July 2011,
<https://www.rfc-editor.org/info/rfc6353>.
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.
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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)
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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
Phone: +1 571 331 5670
Email: kvaughn@trevilon.com
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