< draft-hardaker-isms-dtls-tm-02.txt   draft-hardaker-isms-dtls-tm-03.txt >
ISMS W. Hardaker ISMS W. Hardaker
Internet-Draft Sparta, Inc. Internet-Draft Sparta, Inc.
Intended status: Informational December 10, 2008 Intended status: Standards Track March 9, 2009
Expires: June 13, 2009 Expires: September 10, 2009
Datagram Transport Layer Security Transport Model for SNMP Datagram Transport Layer Security Transport Model for SNMP
draft-hardaker-isms-dtls-tm-02.txt draft-hardaker-isms-dtls-tm-03.txt
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Abstract Abstract
This document describes a Transport Model for the Simple Network This document describes a Transport Model for the Simple Network
Management Protocol (SNMP), that uses the Datagram Transport Layer Management Protocol (SNMP), that uses the Datagram Transport Layer
Security (DTLS) protocol. The DTLS protocol provides authentication Security (DTLS) protocol. The DTLS protocol provides authentication
and privacy services for SNMP applications. This document describes and privacy services for SNMP applications. This document describes
how the DTLS Transport Model (DTLSTM) implements the needed features how the DTLS Transport Model (DTLSTM) implements the needed features
of a SNMP Transport Subsystem to make this protection possible in an of a SNMP Transport Subsystem to make this protection possible in an
interoperable way. interoperable way.
This transport model is designed to meet the security and operational This transport model is designed to meet the security and operational
needs of network administrators, operate in environments where a needs of network administrators, operate in environments where a
connectionless (UDP) transport is preferred, and integrates well into connectionless (e.g. UDP or SCTP) transport is preferred, and
existing public keying infrastructures. integrates well into existing public keying infrastructures.
This document also defines a portion of the Management Information This document also defines a portion of the Management Information
Base (MIB) for monitoring and managing the DTLS Transport Model for Base (MIB) for monitoring and managing the DTLS Transport Model for
SNMP. SNMP.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Requirements Terminology . . . . . . . . . . . . . . . . . 6 1.1. Requirements Terminology . . . . . . . . . . . . . . . . . 7
1.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 6 1.2. Conventions . . . . . . . . . . . . . . . . . . . . . . . 7
2. The Datagram Transport Layer Security Protocol . . . . . . . . 6 2. The Datagram Transport Layer Security Protocol . . . . . . . . 8
2.1. The DTLS Record Protocol . . . . . . . . . . . . . . . . . 7 2.1. The DTLS Record Protocol . . . . . . . . . . . . . . . . . 8
2.2. The DTLS Handshake Protocol . . . . . . . . . . . . . . . 7 2.2. The DTLS Handshake Protocol . . . . . . . . . . . . . . . 9
3. How the DTLSTM fits into the Transport Subsystem . . . . . . . 8 2.3. SNMP requirements of DTLS . . . . . . . . . . . . . . . . 10
3.1. Security Capabilities of this Model . . . . . . . . . . . 10 3. How the DTLSTM fits into the Transport Subsystem . . . . . . . 10
3.1.1. Threats . . . . . . . . . . . . . . . . . . . . . . . 10 3.1. Security Capabilities of this Model . . . . . . . . . . . 12
3.1.2. Message Protection . . . . . . . . . . . . . . . . . . 12 3.1.1. Threats . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.3. DTLS Sessions . . . . . . . . . . . . . . . . . . . . 13 3.1.2. Message Protection . . . . . . . . . . . . . . . . . . 14
3.2. Security Parameter Passing . . . . . . . . . . . . . . . . 14 3.1.3. DTLS Sessions . . . . . . . . . . . . . . . . . . . . 15
3.3. Notifications and Proxy . . . . . . . . . . . . . . . . . 14 3.2. Security Parameter Passing . . . . . . . . . . . . . . . . 15
4. Elements of the Model . . . . . . . . . . . . . . . . . . . . 15 3.3. Notifications and Proxy . . . . . . . . . . . . . . . . . 16
4.1. Certificates . . . . . . . . . . . . . . . . . . . . . . . 15 4. Elements of the Model . . . . . . . . . . . . . . . . . . . . 17
4.1.1. The Certificate Infrastructure . . . . . . . . . . . . 15 4.1. Certificates . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.2. Provisioning for the Certificate . . . . . . . . . . . 16 4.1.1. The Certificate Infrastructure . . . . . . . . . . . . 17
4.2. Messages . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.1.2. Provisioning for the Certificate . . . . . . . . . . . 18
4.3. SNMP Services . . . . . . . . . . . . . . . . . . . . . . 17 4.2. Messages . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3.1. SNMP Services for an Outgoing Message . . . . . . . . 18 4.3. SNMP Services . . . . . . . . . . . . . . . . . . . . . . 19
4.3.2. SNMP Services for an Incoming Message . . . . . . . . 19 4.3.1. SNMP Services for an Outgoing Message . . . . . . . . 19
4.4. DTLS Services . . . . . . . . . . . . . . . . . . . . . . 19 4.3.2. SNMP Services for an Incoming Message . . . . . . . . 20
4.4.1. Services for Establishing a Session . . . . . . . . . 20 4.4. DTLS Services . . . . . . . . . . . . . . . . . . . . . . 21
4.4.2. DTLS Services for an Incoming Message . . . . . . . . 21 4.4.1. Services for Establishing a Session . . . . . . . . . 21
4.4.3. DTLS Services for an Outgoing Message . . . . . . . . 22 4.4.2. DTLS Services for an Incoming Message . . . . . . . . 23
4.5. Cached Information and References . . . . . . . . . . . . 22 4.4.3. DTLS Services for an Outgoing Message . . . . . . . . 24
4.5.1. securityStateReference . . . . . . . . . . . . . . . . 23 4.5. Cached Information and References . . . . . . . . . . . . 24
4.5.2. tmStateReference . . . . . . . . . . . . . . . . . . . 23 4.5.1. DTLS Transport Model Cached Information . . . . . . . 25
4.5.2.1. Transport information . . . . . . . . . . . . . . 24 5. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 25
4.5.2.2. securityName . . . . . . . . . . . . . . . . . . . 24 5.1. Procedures for an Incoming Message . . . . . . . . . . . . 25
4.5.2.3. securityLevel . . . . . . . . . . . . . . . . . . 25 5.1.1. DTLS Processing for Incoming Messages . . . . . . . . 25
4.5.2.4. Session Information . . . . . . . . . . . . . . . 25 5.1.2. Transport Processing for Incoming Messages . . . . . . 27
4.5.3. DTLS Transport Model Cached Information . . . . . . . 26 5.2. Procedures for an Outgoing Message . . . . . . . . . . . . 28
4.5.3.1. Transport Information . . . . . . . . . . . . . . 26 5.3. Establishing a Session . . . . . . . . . . . . . . . . . . 29
4.5.3.2. tmRequestedSecurityLevel . . . . . . . . . . . . . 27 5.4. Closing a Session . . . . . . . . . . . . . . . . . . . . 31
4.5.3.3. tmSecurityLevel . . . . . . . . . . . . . . . . . 27 6. MIB Module Overview . . . . . . . . . . . . . . . . . . . . . 32
4.5.3.4. tmSecurityName . . . . . . . . . . . . . . . . . . 27 6.1. Structure of the MIB Module . . . . . . . . . . . . . . . 32
4.5.4. Transport Model LCD . . . . . . . . . . . . . . . . . 27 6.2. Textual Conventions . . . . . . . . . . . . . . . . . . . 32
5. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 28 6.3. Statistical Counters . . . . . . . . . . . . . . . . . . . 32
5.1. Procedures for an Incoming Message . . . . . . . . . . . . 28 6.4. Configuration Tables . . . . . . . . . . . . . . . . . . . 32
5.1.1. DTLS Processing for Incoming Messages . . . . . . . . 28 6.5. Relationship to Other MIB Modules . . . . . . . . . . . . 33
5.1.2. Transport Processing for Incoming Messages . . . . . . 30 6.5.1. MIB Modules Required for IMPORTS . . . . . . . . . . . 33
5.2. Procedures for an Outgoing Message . . . . . . . . . . . . 31 7. MIB Module Definition . . . . . . . . . . . . . . . . . . . . 33
5.3. Establishing a Session . . . . . . . . . . . . . . . . . . 32 8. Operational Considerations . . . . . . . . . . . . . . . . . . 48
5.4. Closing a Session . . . . . . . . . . . . . . . . . . . . 34 8.1. Sessions . . . . . . . . . . . . . . . . . . . . . . . . . 48
6. MIB Module Overview . . . . . . . . . . . . . . . . . . . . . 35 8.2. Notification Receiver Credential Selection . . . . . . . . 49
6.1. Structure of the MIB Module . . . . . . . . . . . . . . . 35 8.3. contextEngineID Discovery . . . . . . . . . . . . . . . . 49
6.2. Textual Conventions . . . . . . . . . . . . . . . . . . . 35 9. Security Considerations . . . . . . . . . . . . . . . . . . . 49
6.3. Statistical Counters . . . . . . . . . . . . . . . . . . . 35 9.1. Certificates, Authentication, and Authorization . . . . . 50
6.4. Configuration Tables . . . . . . . . . . . . . . . . . . . 35 9.2. Use with SNMPv1/SNMPv2c Messages . . . . . . . . . . . . . 51
6.5. Relationship to Other MIB Modules . . . . . . . . . . . . 35 9.3. MIB Module Security . . . . . . . . . . . . . . . . . . . 51
6.5.1. MIB Modules Required for IMPORTS . . . . . . . . . . . 36 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 51
7. MIB Module Definition . . . . . . . . . . . . . . . . . . . . 36 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 52
8. Operational Considerations . . . . . . . . . . . . . . . . . . 49 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.1. Sessions . . . . . . . . . . . . . . . . . . . . . . . . . 49 12.1. Normative References . . . . . . . . . . . . . . . . . . . 52
8.2. Notification Receiver Credential Selection . . . . . . . . 50 12.2. Informative References . . . . . . . . . . . . . . . . . . 54
8.3. contextEngineID Discovery . . . . . . . . . . . . . . . . 50 Appendix A. Target and Notificaton Configuration Example . . . . 55
9. Security Considerations . . . . . . . . . . . . . . . . . . . 50 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 57
9.1. Certificates, Authentication, and Authorization . . . . . 51
9.2. Use with SNMPv1/SNMPv2c Messages . . . . . . . . . . . . . 52
9.3. MIB Module Security . . . . . . . . . . . . . . . . . . . 52
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 52
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 53
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 53
12.1. Normative References . . . . . . . . . . . . . . . . . . . 53
12.2. Informative References . . . . . . . . . . . . . . . . . . 55
Appendix A. Target and Notificaton Configuration Example . . . . 56
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 58
Intellectual Property and Copyright Statements . . . . . . . . . . 59
1. Introduction 1. Introduction
It is important to understand the SNMPv3 architecture [RFC3411], as It is important to understand the SNMPv3 architecture [RFC3411], as
enhanced by the Transport Subsystem [I-D.ietf-isms-tmsm]. It is also enhanced by the Transport Subsystem [I-D.ietf-isms-tmsm]. It is also
important to understand the terminology of the SNMPv3 architecture in important to understand the terminology of the SNMPv3 architecture in
order to understand where the Transport Model described in this order to understand where the Transport Model described in this
document fits into the architecture and how it interacts with the document fits into the architecture and how it interacts with the
other architecture subsystems. For a detailed overview of the other architecture subsystems. For a detailed overview of the
documents that describe the current Internet-Standard Management documents that describe the current Internet-Standard Management
Framework, please refer to Section 7 of [RFC3410]. Framework, please refer to Section 7 of [RFC3410].
This document describes a Transport Model that makes use of the This document describes a Transport Model that makes use of the
Datagram Transport Layer Security (DTLS) Protocol [RFC4347], the Datagram Transport Layer Security (DTLS) Protocol [RFC4347], the
datagram variant of the existing and commonly deployed Transport datagram variant of the existing and commonly deployed Transport
Layer Security (TLS) protocol [RFC4346], within a transport subsystem Layer Security (TLS) protocol [RFC5246], within a transport subsystem
[I-D.ietf-isms-tmsm]. The Transport Model in this document is [I-D.ietf-isms-tmsm]. The Transport Model in this document is
referred to as the Datagram Transport Layer Security Transport Model referred to as the Datagram Transport Layer Security Transport Model
(DTLSTM). DTLS takes advantage of the X.509 public keying (DTLSTM). DTLS takes advantage of the X.509 public keying
infrastructure [X509]. This transport model is designed to meet the infrastructure [X509]. This transport model is designed to meet the
security and operational needs of network administrators, operate in security and operational needs of network administrators, operate in
environments where a connectionless (UDP) transport is preferred, and environments where a connectionless (e.g. UDP or SCTP) transport is
integrate well into existing public keying infrastructures. preferred, and integrate well into existing public keying
infrastructures.
Managed objects are accessed via a virtual information store, termed Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP). accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This document specifies a Structure of Management Information (SMI). This memo specifies a MIB
MIB module that is compliant to the SMIv2, which is described in STD module that is compliant to the SMIv2, which is described in STD 58,
58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
2580 [RFC2580]. [RFC2580].
This document also defines a portion of the Management Information This document also specifies a portion of the Management Information
Base (MIB) for use with network management protocols in IP based Base (MIB) to define objects for monitoring and managing the DTLS
networks. In particular it defines objects for monitoring and Transport Model for SNMP.
managing the DTLS Transport Model for SNMP.
The diagram shown below gives a conceptual overview of two SNMP The diagram shown below gives a conceptual overview of two SNMP
entities communicating using the DTLS Transport Model. One entity entities communicating using the DTLS Transport Model. One entity
contains a Command Responder and Notification Originator application, contains a Command Responder and Notification Originator application,
and the other a Command Generator and Notification Responder and the other a Command Generator and Notification Responder
application. It should be understood that this particular mix of application. It should be understood that this particular mix of
application types is an example only and other combinations are application types is an example only and other combinations are
equally as legitimate. equally as legitimate.
+----------------------------------------------------------------+ +----------------------------------------------------------------+
skipping to change at page 5, line 18 skipping to change at page 6, line 15
^ ^ ^ ^ ^ ^ ^ ^
|Notifications |Commands |Commands |Notifications |Notifications |Commands |Commands |Notifications
+---|---------------------|--------+ +--|---------------|-------------+ +---|---------------------|--------+ +--|---------------|-------------+
| V V | | V V | | V V | | V V |
| +------------+ +------------+ | | +-----------+ +----------+ | | +------------+ +------------+ | | +-----------+ +----------+ |
| | DTLS | | DTLS | | | | DTLS | | DTLS | | | | DTLS | | DTLS | | | | DTLS | | DTLS | |
| | Service | | Service | | | | Service | | Service | | | | Service | | Service | | | | Service | | Service | |
| | (Client) | | (Server) | | | | (Client) | | (Server)| | | | (Client) | | (Server) | | | | (Client) | | (Server)| |
| +------------+ +------------+ | | +-----------+ +----------+ | | +------------+ +------------+ | | +-----------+ +----------+ |
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
| | | | | | | |
| +--+----------+ | | +-+--------------+ | | +--+----------+ | | +-+--------------+ |
| +-----|---------+----+ | | +---|--------+----+ | | +-----|---------+----+ | | +---|--------+----+ |
| | V |LCD | +-------+ | | | V |LCD | +--------+ | | | V |LCD | +-------+ | | | V |LCD | +--------+ |
| | +------+ +----+ | | | | | +------+ +----+ | | | | | +------+ +----+ | | | | | +------+ +----+ | | |
| | | DTLS | <---------->| Cache | | | | | DTLS | <---->| Cache | | | | | DTLS | <---------->| Cache | | | | | DTLS | <---->| Cache | |
| | | TM | | | | | | | | TM | | | | | | | | TM | | | | | | | | TM | | | | |
| | +------+ | +-------+ | | | +------+ | +--------+ | | | +------+ | +-------+ | | | +------+ | +--------+ |
| |Transport Subsystem | ^ | | |Transport Sub. | ^ | | |Transport Subsystem | ^ | | |Transport Sub. | ^ |
| +--------------------+ | | | +-----------------+ | | | +--------------------+ | | | +-----------------+ | |
| ^ +----+ | | ^ | | | ^ +----+ | | ^ | |
skipping to change at page 5, line 40 skipping to change at page 6, line 38
| +-------+ +----------+ +-----+ | | | +-----+ +------+ +-----+ | | | +-------+ +----------+ +-----+ | | | +-----+ +------+ +-----+ | |
| | | |Message | |Sec. | | | | | | | MP | |Sec. | | | | | | |Message | |Sec. | | | | | | | MP | |Sec. | | |
| | Disp. | |Processing| |Sub- | | | | |Disp.| | Sub- | |Sub- | | | | | Disp. | |Processing| |Sub- | | | | |Disp.| | Sub- | |Sub- | | |
| | | |Subsystem | |sys. | | | | | | |system| |sys. | | | | | | |Subsystem | |sys. | | | | | | |system| |sys. | | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| | | | | |+---+| | | | | | | | |+---+| | | | | | | | |+---+| | | | | | | | |+---+| | |
| | | | +-----+ | || || | | | | | |+----+| || || | | | | | | +-----+ | || || | | | | | |+----+| || || | |
| | <--->|v3MP |<-->||TSM|<-+ | | | <-->|v3MP|<->|TSM|<-+ | | | <--->|v3MP |<-->||TSM|<-+ | | | <-->|v3MP|<->|TSM|<-+ |
| | | | +-----+ | || || | | | | |+----+| || || | | | | | +-----+ | || || | | | | |+----+| || || |
| +-------+ | | |+---+| | | +-----+ | | |+---+| | | +-------+ | | |+---+| | | +-----+ | | |+---+| |
| ^ | | | | | | ^ | | | | | | ^ | | | | | | ^ | | | | |
| | +----------+ +-----+ | | | +------+ +-----+ | | | +----------+ +-----+ | | | +------+ +-----+ |
| +-+----------+ | | +-+------------+ | | +-+------------+ | | +-+------------+ |
| ^ ^ | | ^ ^ | | ^ ^ | | ^ ^ |
| | | | | | | | | | | | | | | |
| v v | | V V | | v v | | V V |
| +-------------+ +--------------+ | | +-----------+ +--------------+ | | +-------------+ +--------------+ | | +-----------+ +--------------+ |
| | COMMAND | | NOTIFICATION | | | | COMMAND | | NOTIFICATION | | | | COMMAND | | NOTIFICATION | | | | COMMAND | | NOTIFICATION | |
| | RESPONDER | | ORIGINATOR | | | | GENERATOR | | RESPONDER | | | | RESPONDER | | ORIGINATOR | | | | GENERATOR | | RESPONDER | |
| | application | | applications | | | |application| | application | | | | application | | applications | | | |application| | application | |
| +-------------+ +--------------+ | | +-----------+ +--------------+ | | +-------------+ +--------------+ | | +-----------+ +--------------+ |
| SNMP entity | | SNMP entity | | SNMP entity | | SNMP entity |
+----------------------------------+ +--------------------------------+ +----------------------------------+ +--------------------------------+
skipping to change at page 6, line 15 skipping to change at page 7, line 15
1.1. Requirements Terminology 1.1. Requirements Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
1.2. Conventions 1.2. Conventions
For consistency with SNMP-related specifications, this document For consistency with SNMP-related specifications, this document
favors terminology as defined in STD62 rather than favoring favors terminology as defined in STD62 rather than favoring
terminology that is consistent with non-SNMP specifications that use terminology that is consistent with non-SNMP specifications. This is
different variations of the same terminology. This is consistent consistent with the IESG decision to not require the SNMPv3
with the IESG decision to not require the SNMPv3 terminology be terminology be modified to match the usage of other non-SNMP
modified to match the usage of other non-SNMP specifications when specifications when SNMPv3 was advanced to Full Standard.
SNMPv3 was advanced to Full Standard.
In particular, where distinction is required the application names of Authentication in this document typically refers to the English
"Command Generator", "Command Responder", "Notification Originator", meaning of "serving to prove the authenticity of" the message, not
"Notification Receiver", and "Proxy Forwarder" are used. See the data source authentication or peer identity authentication.
"SNMP Applications" in [RFC3413] for further information.
Authentication in this document typically refers to source The terms "manager" and "agent" are not used in this document,
authentication or peer identity authentication performed in the because in the RFC 3411 architecture [RFC3411], all SNMP entities
transport subsystem. have the capability of acting in either manager or agent or in both
roles depending on the SNMP application types supported in the
implementation. Where distinction is required, the application names
of Command Generator, Command Responder, Notification Originator,
Notification Receiver, and Proxy Forwarder are used. See "SNMP
Applications" [RFC3413] for further information.
Throughout this document, the terms "client" and "server" are used to
refer to the two ends of the SSH transport connection. The client
actively opens the SSH connection, and the server passively listens
for the incoming SSH connection. Either SNMP entity may act as
client or as server, as discussed further below.
The User-Based Security Model (USM) [RFC3414] is a mandatory-to-
implement Security Model in STD 62. While SSH and USM frequently
refer to a user, the terminology preferred in RFC3411 [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.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Throughout this document, the terms "client" and "server" are used to Throughout this document, the terms "client" and "server" are used to
refer to the two ends of the DTLS session. The client actively opens refer to the two ends of the DTLS session. The client actively opens
the DTLS session, and the server passively listens for the incoming the DTLS session, and the server passively listens for the incoming
DTLS session. Any SNMP entity may act as client or as server. DTLS session. Any SNMP entity may act as a client or as a server.
While security protocols frequently refer to a "user", the term used While security protocols (like DTLS [RFC4347] and USM [RFC3414])
in RFC3411 [RFC3411] and in this document is "principal". A frequently refer to a "user", the terminology preferred in RFC3411
principal is the "who" on whose behalf services are provided or [RFC3411] and in this document is "principal". A principal is the
processing takes place. A principal can be, among other things, an "who" on whose behalf services are provided or processing takes
individual acting in a particular role; a set of individuals, with place. A principal can be, among other things, an individual acting
each acting in a particular role; an application or a set of in a particular role; a set of individuals, with each acting in a
applications, or a combination of these within an administrative particular role; an application or a set of applications, or a
domain. combination of these within an administrative domain.
Throughout this document, the term "session" is used to refer to a Throughout this document, the term "session" is used to refer to a
secure association between two DTLS Transport Models that permits the secure association between two DTLS Transport Models that permits the
transmission of one or more SNMP messages within the lifetime of the transmission of one or more SNMP messages within the lifetime of the
session. session.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. The Datagram Transport Layer Security Protocol 2. The Datagram Transport Layer Security Protocol
The DTLS protocol is a datagram-compatible variant of the commonly The DTLS protocol is a datagram-compatible variant of the commonly
used Transport Layer Security (TLS) protocol. DTLS provides used Transport Layer Security (TLS) protocol. DTLS provides
authentication, data message integrity, and privacy at the transport authentication, data message integrity, and privacy at the transport
layer. (See [RFC4347]) layer. (See [RFC4347])
The primary goals of the DTLS Transport Model are to provide privacy, The primary goals of the DTLS Transport Model are to provide privacy,
source authentication and data integrity between two communicating source authentication and data integrity between two communicating
SNMP entities. The DTLS protocol is composed of two layers: the DTLS SNMP entities. The DTLS protocol is composed of two layers: the DTLS
Record Protocol and the DTLS Handshake Protocol. The following Record Protocol and the DTLS Handshake Protocol. The following
sections provide an overview of these two layers. Please refer to sections provide an overview of these two layers. Please refer to
[RFC4347] for a complete description of the protocol. [RFC4347] for a complete description of the protocol. Readers
familiar with DTLS can skip Section 2 except for section Section 2.3.
2.1. The DTLS Record Protocol 2.1. The DTLS Record Protocol
At the lowest layer, layered on top of the transport protocol (UDP) At the lowest layer, layered on top of a datagram transport protocol
is the DTLS Record Protocol. (e.g. UDP or SCTP) is the DTLS Record Protocol.
The DTLS Record Protocol provides security that has three basic The DTLS Record Protocol provides security that has three basic
properties: properties:
o The session can be confidential. Symmetric cryptography is used o The session can be confidential. Symmetric cryptography is used
for data encryption (e.g., AES [AES], DES [DES] etc.). The keys for data encryption (e.g., AES [AES], DES [DES] etc.). The keys
for this symmetric encryption are generated uniquely for each for this symmetric encryption are generated uniquely for each
session and are based on a secret negotiated by another protocol session and are based on a secret negotiated by another protocol
(such as the DTLS Handshake Protocol). The Record Protocol can (such as the DTLS Handshake Protocol). The Record Protocol can
also be used without encryption. also be used without encryption.
skipping to change at page 7, line 50 skipping to change at page 9, line 32
DTLS also provides protection against replay of entire sessions. In DTLS also provides protection against replay of entire sessions. In
a properly-implemented keying material exchange, both sides will a properly-implemented keying material exchange, both sides will
generate new random numbers for each exchange. This results in generate new random numbers for each exchange. This results in
different encryption and integrity keys for every session. different encryption and integrity keys for every session.
2.2. The DTLS Handshake Protocol 2.2. The DTLS Handshake Protocol
The DTLS Record Protocol is used for encapsulation of various higher- The DTLS Record Protocol is used for encapsulation of various higher-
level protocols. One such encapsulated protocol, the DTLS Handshake level protocols. One such encapsulated protocol, the DTLS Handshake
Protocol, allows server and client to authenticate each other and to Protocol, allows the server and client to authenticate each other and
negotiate an encryption algorithm and cryptographic keys before the to negotiate an integrity algorithm, an encryption algorithm and
application protocol transmits or receives its first octet of data. cryptographic keys before the application protocol transmits or
Only the DTLS client can initiate the handshake protocol. The DTLS receives its first octet of data. Only the DTLS client can initiate
Handshake Protocol provides security that has three basic properties: the handshake protocol. The DTLS Handshake Protocol provides
security that has three basic properties:
o The peer's identity can be authenticated using asymmetric, or o The peer's identity can be authenticated using asymmetric (public
public key, cryptography (e.g., RSA [RSA], DSS [DSS], etc.). This key) cryptography (e.g., RSA [RSA], DSS [DSS], etc.). This
authentication can be made optional, but is generally required by authentication can be made optional, but is generally required by
at least one of the peers. at least one of the peers.
DTLS supports three authentication modes: authentication of both the DTLS supports three authentication modes: authentication of both
server and the client, server authentication with an unauthenticated the server and the client, server authentication with an
client, and total anonymity. For authentication of both entities, unauthenticated client, and total anonymity. For authentication
each entity provides a valid certificate chain leading to an of both entities, each entity provides a valid certificate chain
acceptable certificate authority. Each entity is responsible for leading to an acceptable certificate authority. Each entity is
verifying that the other's certificate is valid and has not expired responsible for verifying that the other's certificate is valid
or been revoked. The DTLS Transport Model SHOULD always use and has not expired or been revoked. See
authentication of both the server and the client. At a minimum the [I-D.hodges-server-ident-check] for further details on
DTLS Transport MUST support authentication of the Command Generator standardized processing when checking Server certificate
principals to guarantee the authenticity of the securityName (a identities.
parameter used to pass the authenticated identity name from the
transport model to security model for even later use by the access
control subsystem. See Section 4.5.3.4). The DTLS Transport SHOULD
support the message encryption to protect sensitive data from
eavesdropping attacks. See [I-D.hodges-server-ident-check] for
further details on standardized processing when checking Server
certificate identities.
o The negotiation of a shared secret is secure: the negotiated o The negotiation of a shared secret is secure: the negotiated
secret is unavailable to eavesdroppers, and for any authenticated secret is unavailable to eavesdroppers, and for any authenticated
handshake the secret cannot be obtained, even by an attacker who handshake the secret cannot be obtained, even by an attacker who
can place himself in the middle of the session. can place himself in the middle of the session.
o The negotiation is not vulnerable to malicious modification: it is o The negotiation is not vulnerable to malicious modification: it is
infeasible for an attacker to modify negotiation communication infeasible for an attacker to modify negotiation communication
without being detected by the parties to the communication. without being detected by the parties to the communication.
o DTLS uses a stateless cookie exchange to protect against anonymous o DTLS uses a stateless cookie exchange to protect against anonymous
denial of service attacks and has retransmission timers, sequence denial of service attacks and has retransmission timers, sequence
numbers, and counters to handle message loss, reordering, and numbers, and counters to handle message loss, reordering, and
fragmentation. fragmentation.
2.3. SNMP requirements of DTLS
To properly support the SNMP over DTLS Transport Model, the DTLS
implementation requires the following:
o The DTLS Transport Model SHOULD always use authentication of both
the server and the client.
o At a minimum the DTLS Transport MUST support authentication of the
Command Generator principals to guarantee the authenticity of the
securityName (a parameter used to pass the authenticated identity
name from the transport model to security model for even later use
by the access control subsystem).
o The DTLS Transport SHOULD support the message encryption to
protect sensitive data from eavesdropping attacks.
3. How the DTLSTM fits into the Transport Subsystem 3. How the DTLSTM fits into the Transport Subsystem
A transport model is a component of the Transport Subsystem. The A transport model is a component of the Transport Subsystem. The
DTLS Transport Model thus fits between the underlying DTLS transport DTLS Transport Model thus fits between the underlying DTLS transport
layer and the message Dispatcher [RFC3411] component of the SNMP layer and the message Dispatcher [RFC3411] component of the SNMP
engine and the Transport Subsystem [I-D.ietf-isms-tmsm]. engine and the Transport Subsystem.
The DTLS Transport Model will establish a session between itself and The DTLS Transport Model will establish a session between itself and
the DTLS Transport Model of another SNMP engine. The sending the DTLS Transport Model of another SNMP engine. The sending
transport model passes unprotected messages from the dispatcher to transport model passes unprotected messages from the dispatcher to
DTLS to be protected, and the receiving transport model accepts DTLS to be protected, and the receiving transport model accepts
decrypted and authenticated/integrity-checked incoming messages from decrypted and authenticated/integrity-checked incoming messages from
DTLS and passes them to the dispatcher. DTLS and passes them to the dispatcher.
After a DTLS Transport model session is established, SNMP messages After a DTLS Transport model session is established, SNMP messages
can conceptually be sent through the session from one SNMP message can conceptually be sent through the session from one SNMP message
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falsifying the value of an object. falsifying the value of an object.
DTLS provides verification that the content of each received DTLS provides verification that the content of each received
message has not been modified during its transmission through the message has not been modified during its transmission through the
network, data has not been altered or destroyed in an network, data has not been altered or destroyed in an
unauthorized manner, and data sequences have not been altered to unauthorized manner, and data sequences have not been altered to
an extent greater than can occur non-maliciously. an extent greater than can occur non-maliciously.
2. Masquerade - The masquerade threat is the danger that management 2. Masquerade - The masquerade threat is the danger that management
operations unauthorized for a given principal may be attempted by operations unauthorized for a given principal may be attempted by
assuming the identity of a principal with appropriate assuming the identity of another principal that has the
authorizations. appropriate authorizations.
The DTLSTM provides for authentication of the Principal Command The DTLSTM provides for authentication of the Command Generator,
Generator and Notification Generator and for authentication of Command Responder, Notification Generator, Notification Responder
the Command Responder, Notification Responder and Proxy Forwarder and Proxy Forwarder through the use of X.509 certificates.
through the use of X.509 certificates.
The masquerade threat can be mitigated against by using an The masquerade threat can be mitigated against by using an
appropriate Access Control Model (ACM) such as the View-based appropriate Access Control Model (ACM) such as the View-based
Access Control Module (VACM) [RFC3415]. In addition, it is Access Control Module (VACM) [RFC3415]. In addition, it is
important to authenticate and verify both the authenticated important to authenticate and verify both the authenticated
identity of the DTLS client and the DTLS server to protect identity of the DTLS client and the DTLS server to protect
against this threat. (See Section 9 for more detail.) against this threat. (See Section 9 for more detail.)
3. Message stream modification - The re-ordering, delay or replay of 3. Message stream modification - The re-ordering, delay or replay of
messages can and does occur through the natural operation of many messages can and does occur through the natural operation of many
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Records that are too old to fit in the window and records that Records that are too old to fit in the window and records that
have previously been received are silently discarded. The replay have previously been received are silently discarded. The replay
detection feature is optional, since packet duplication can also detection feature is optional, since packet duplication can also
occur naturally due to routing errors and does not necessarily occur naturally due to routing errors and does not necessarily
indicate an active attack. Applications may conceivably detect indicate an active attack. Applications may conceivably detect
duplicate packets and accordingly modify their data transmission duplicate packets and accordingly modify their data transmission
strategy. strategy.
4. Disclosure - The disclosure threat is the danger of eavesdropping 4. Disclosure - The disclosure threat is the danger of eavesdropping
on the exchanges between SNMP engines. Protecting against this on the exchanges between SNMP engines. Protecting against this
threat may be required as a matter of local policy. threat may be required by local policy at the deployment site.
Symmetric cryptography (e.g., AES [AES], DES [DES] etc.) can be Symmetric cryptography (e.g., AES [AES], DES [DES] etc.) can be
used by DTLS for data privacy. The keys for this symmetric used by DTLS for data privacy. The keys for this symmetric
encryption are generated uniquely for each session and are based encryption are generated uniquely for each session and are based
on a secret negotiated by another protocol (such as the DTLS on a secret negotiated by another protocol (such as the DTLS
Handshake Protocol). Handshake Protocol).
5. Denial of Service - the RFC 3411 architecture [RFC3411] states 5. Denial of Service - the RFC 3411 architecture [RFC3411] states
that denial of service (DoS) attacks need not be addressed by an that denial of service (DoS) attacks need not be addressed by an
SNMP security protocol. However, datagram security protocols are SNMP security protocol. However, datagram security protocols are
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generators or notification originators. Command generators are generators or notification originators. Command generators are
frequently operated by a human, but notification originators are frequently operated by a human, but notification originators are
usually unmanned automated processes. The targets to whom usually unmanned automated processes. The targets to whom
notifications should be sent is typically determined and configured notifications should be sent is typically determined and configured
by a network administrator. by a network administrator.
The SNMP-TARGET-MIB module [RFC3413] contains objects for defining The SNMP-TARGET-MIB module [RFC3413] contains objects for defining
management targets, including transportDomain, transportAddress, management targets, including transportDomain, transportAddress,
securityName, securityModel, and securityLevel parameters, for securityName, securityModel, and securityLevel parameters, for
Notification Generator, Proxy Forwarder, and SNMP-controllable Notification Generator, Proxy Forwarder, and SNMP-controllable
Command Generator applications. Transport domain and transport Command Generator applications. Transport domains and transport
address are configured in the snmpTargetAddrTable, and the addresses are configured in the snmpTargetAddrTable, and the
securityModel, securityName, and securityLevel parameters are securityModel, securityName, and securityLevel parameters are
configured in the snmpTargetParamsTable. This document defines a MIB configured in the snmpTargetParamsTable. This document defines a MIB
module that extends the SNMP-TARGET-MIB's snmpTargetParamsTable to module that extends the SNMP-TARGET-MIB's snmpTargetParamsTable to
specify a DTLS client-side certificate to use for the connection. specify a DTLS client-side certificate to use for the connection.
When configuring a DTLS target, the snmpTargetAddrTDomain and When configuring a DTLS target, the snmpTargetAddrTDomain and
snmpTargetAddrTAddress parameters in snmpTargetAddrTable should be snmpTargetAddrTAddress parameters in snmpTargetAddrTable should be
set to the snmpDTLSDomain object and an appropriate snmpDTLSAddress set to the snmpDTLSUDPDomain or snmpDTLSSCTPDomain object and an
value respectively. The snmpTargetParamsMPModel column of the appropriate snmpDTLSUDPAddress or snmpDTLSSCTPAddress value
respectively. The snmpTargetParamsMPModel column of the
snmpTargetParamsTable should be set to a value of 3 to indicate the snmpTargetParamsTable should be set to a value of 3 to indicate the
SNMPv3 message processing model. The snmpTargetParamsSecurityName SNMPv3 message processing model. The snmpTargetParamsSecurityName
should be set to an appropriate securityName value and the should be set to an appropriate securityName value and the
dtlstmParamsHashType and dtlstmParamsHashValue parameters of the dtlstmParamsHashType and dtlstmParamsHashValue parameters of the
dtlstmParamsTable should be set to values that refer to a locally dtlstmParamsTable should be set to values that refer to a locally
held certificate to be used. Other parameters, for example held certificate to be used. Other parameters, for example
cryptographic configuration such as cipher suites to use, must come cryptographic configuration such as cipher suites to use, must come
from configuration mechanisms not defined in this document. The from configuration mechanisms not defined in this document. The
other needed configuration may be configured using SNMP or other other needed configuration may be configured using SNMP or other
implementation-dependent mechanisms (for example, via a CLI). This implementation-dependent mechanisms (for example, via a CLI). This
securityName defined in the snmpTargetParamsSecurityName column will securityName defined in the snmpTargetParamsSecurityName column will
be used by the access control model to authorize any notifications be used by the access control model to authorize any notifications
that need to be sent. that need to be sent.
4. Elements of the Model 4. Elements of the Model
This section contains definitions required to realize the DTLS This section contains definitions required to realize the DTLS
Transport Model defined by this document. Transport Model defined by this document. Readers familiar with
X.509 certificates can skip this section until Section 4.1.2.
4.1. Certificates 4.1. Certificates
DTLS makes use of X.509 certificates for authentication of both sides DTLS makes use of X.509 certificates for authentication of both sides
of the transport. This section discusses the use of certificates in of the transport. This section discusses the use of certificates in
DTLS and the its effects on SNMP over DTLS. DTLS and the its effects on SNMP over DTLS.
4.1.1. The Certificate Infrastructure 4.1.1. The Certificate Infrastructure
Users of a public key SHALL be confident that the associated private Users of a public key SHALL be confident that the associated private
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first published in 1988 as part of the X.500 Directory first published in 1988 as part of the X.500 Directory
recommendations, defines a standard certificate format [X509] which recommendations, defines a standard certificate format [X509] which
is a certificate which binds a subject (principal) to a public key is a certificate which binds a subject (principal) to a public key
value. This was later further documented in [RFC5280]. value. This was later further documented in [RFC5280].
A X.509 certificate is a sequence of three required fields: A X.509 certificate is a sequence of three required fields:
tbsCertificate: The field contains the names of the subject and tbsCertificate: The field contains the names of the subject and
issuer, a public key associated with the subject, a validity issuer, a public key associated with the subject, a validity
period, and other associated information. This field may also period, and other associated information. This field may also
contain extensions. contain extension components.
signatureAlgorithm: The signatureAlgorithm field contains the signatureAlgorithm: The signatureAlgorithm field contains the
identifier for the cryptographic algorithm used by the certificate identifier for the cryptographic algorithm used by the certificate
authority (CA) to sign this certificate. authority (CA) to sign this certificate.
signatureValue: The signatureValue field contains a digital signatureValue: The signatureValue field contains a digital
signature computed upon the ASN.1 DER encoded tbsCertificate signature computed upon the ASN.1 DER encoded tbsCertificate
field. The ASN.1 DER encoded tbsCertificate is used as the input field. The ASN.1 DER encoded tbsCertificate is used as the input
to the signature function. This signature value is then ASN.1 DER to the signature function. This signature value is then ASN.1 DER
encoded as a BIT STRING and included in the Certificate's encoded as a BIT STRING and included in the Certificate's
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An example mapping setup can be found in Appendix A An example mapping setup can be found in Appendix A
This tmSecurityName may be later translated from a DTLSSM specific This tmSecurityName may be later translated from a DTLSSM specific
tmSecurityName to a SNMP engine securityName by the security model. tmSecurityName to a SNMP engine securityName by the security model.
A security model, like the TSM security model, may perform an A security model, like the TSM security model, may perform an
identity mapping or a more complex mapping to derive the securityName identity mapping or a more complex mapping to derive the securityName
from the tmSecurityName offered by the DTLS Transport Model. from the tmSecurityName offered by the DTLS Transport Model.
4.2. Messages 4.2. Messages
As stated in RFC4347, each DTLS message must fit within a single As stated in Section 4.1.1 of [RFC4347], each DTLS record must fit
datagram. The DTLSTM MUST prohibit SNMP messages from being set that within a single DTLS datagram. The DTLSTM SHOULD prohibit SNMP
exceed the MTU size. The DTLSTM implementation MUST return an error messages from being sent that exceeds the maximum DTLS message. The
when the MTU size would be exceeded and the message won't be sent. DTLSTM implementation SHOULD return an error when the DTLS message
size would be exceeded and the message won't be sent.
For Ethernet the MTU size is 1500 and thus the maximum allowable SNMP
message that can be sent over DTLSTM after UDP/IP/DTLS overhead is
taken into account will be 1455 for IPv6 (MTU:1500 - IPv6:40 - UDP:8
- DTLS:13) and 1475 for IPv4 (MTU:1500 - IPv4:20 - UDP:8 - DTLS:13).
From this integrity and encryption overhead also needs to be
subtracted, which are integrity and encryption algorithm specific.
4.3. SNMP Services 4.3. SNMP Services
This section describes the services provided by the DTLS Transport This section describes the services provided by the DTLS Transport
Model with their inputs and outputs. The services are between the Model with their inputs and outputs. The services are between the
Transport Model and the Dispatcher. Transport Model and the Dispatcher.
The services are described as primitives of an abstract service The services are described as primitives of an abstract service
interface (ASI) and the inputs and outputs are described as abstract interface (ASI) and the inputs and outputs are described as abstract
data elements as they are passed in these abstract service data elements as they are passed in these abstract service
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statusInformation: An indication of whether the passing of the statusInformation: An indication of whether the passing of the
message was successful. If not it is an indication of the message was successful. If not it is an indication of the
problem. problem.
destTransportDomain: The transport domain for the associated destTransportDomain: The transport domain for the associated
destTransportAddress. The Transport Model uses this parameter to destTransportAddress. The Transport Model uses this parameter to
determine the transport type of the associated determine the transport type of the associated
destTransportAddress. This parameter may also be used by the destTransportAddress. This parameter may also be used by the
transport subsystem to route the message to the appropriate transport subsystem to route the message to the appropriate
Transport Model. Transport Model. This document specifies two DTLS based Transport
Domains for use: the snmpDTLSUDPDomain and the snmpDTLSSCTPDomain.
destTransportAddress: The transport address of the destination DTLS destTransportAddress: The transport address of the destination DTLS
Transport Model in a format specified by the SnmpDTLSAddress Transport Model in a format specified by the SnmpDTLSUDPAddress or
TEXTUAL-CONVENTION. the SnmpDTLSSCTPAddress TEXTUAL-CONVENTIONs.
outgoingMessage: The outgoing message to send to DTLS for outgoingMessage: The outgoing message to send to DTLS for
encapsulation. encapsulation.
outgoingMessageLength: The length of the outgoing message. outgoingMessageLength: The length of the outgoing message.
tmStateReference: A handle/reference to tmSecurityData to be used tmStateReference: A handle/reference to tmSecurityData to be used
when securing outgoing messages. when securing outgoing messages.
4.3.2. SNMP Services for an Incoming Message 4.3.2. SNMP Services for an Incoming Message
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) )
The abstract data elements passed as parameters in the abstract The abstract data elements passed as parameters in the abstract
service primitives are as follows: service primitives are as follows:
statusInformation: An indication of whether the passing of the statusInformation: An indication of whether the passing of the
message was successful. If not it is an indication of the message was successful. If not it is an indication of the
problem. problem.
transportDomain: The transport domain for the associated transportDomain: The transport domain for the associated
transportAddress. transportAddress. This document specifies two DTLS based
Transport Domains for use: the snmpDTLSUDPDomain and the
snmpDTLSSCTPDomain.
transportAddress: The transport address of the source of the transportAddress: The transport address of the source of the
received message in a format specified by the SnmpDTLSAddress received message in a format specified by the SnmpDTLSUDPAddress
TEXTUAL-CONVENTION. or the SnmpDTLSSCTPAddress TEXTUAL-CONVENTION.
incomingMessage: The whole SNMP message stripped of all DTLS incomingMessage: The whole SNMP message stripped of all DTLS
protection data. protection data.
incomingMessageLength: The length of the SNMP message after being incomingMessageLength: The length of the SNMP message after being
processed by DTLS. processed by DTLS.
tmStateReference: A handle/reference to tmSecurityData to be used by tmStateReference: A handle/reference to tmSecurityData to be used by
the security model. the security model.
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The abstract data elements passed as parameters in the abstract The abstract data elements passed as parameters in the abstract
service primitives are as follows: service primitives are as follows:
statusInformation: An indication of whether the process was statusInformation: An indication of whether the process was
successful or not. If not, then the status information will successful or not. If not, then the status information will
include the error indication provided by DTLS. include the error indication provided by DTLS.
destTransportDomain: The transport domain for the associated destTransportDomain: The transport domain for the associated
destTransportAddress. The DTLS Transport Model uses this destTransportAddress. The DTLS Transport Model uses this
parameter to determine the transport type of the associated parameter to determine the transport type of the associated
destTransportAddress. destTransportAddress. This document specifies two DTLS based
Transport Domains for use: the snmpDTLSUDPDomain and the
snmpDTLSSCTPDomain.
destTransportAddress: The transport address of the destination DTLS destTransportAddress: The transport address of the destination DTLS
Transport Model in a format specified by the SnmpDTLSAddress Transport Model in a format specified by the SnmpDTLSUDPAddress or
TEXTUAL-CONVENTION. the SnmpDTLSSCTPAddress TEXTUAL-CONVENTION.
securityName: The security name representing the principal on whose securityName: The security name representing the principal on whose
behalf the message will be sent. behalf the message will be sent.
securityLevel: The level of security requested by the application. securityLevel: The level of security requested by the application.
dtlsSessionID: An implementation-dependent session identifier to dtlsSessionID: An implementation-dependent session identifier to
reference the specific DTLS session. reference the specific DTLS session.
DTLS and UDP do not provide a session de-multiplexing mechanism and DTLS and UDP do not provide a session de-multiplexing mechanism and
it is possible that implementations will only be able to identify a it is possible that implementations will only be able to identify a
unique session based on a unique combination of source address, unique session based on a unique combination of source address,
destination address, source UDP port number and destination UDP port destination address, source UDP port number and destination UDP port
number. Because of this, when establishing a new sessions number. Because of this, when establishing a new sessions
implementations MUST use a different UDP source port number for each implementations MUST use a different UDP source port number for each
connection to a remote destination IP-address/port-number combination connection to a remote destination IP-address/port-number combination
to ensure the remote entity can properly disambiguate between to ensure the remote entity can properly disambiguate between
multiple sessions from a host to the same port on a server. multiple sessions from a host to the same port on a server. SCTP
does provide session de-multiplexing so this restriction is not
needed for DTLS/SCTP implementations.
The procedural details for establishing a session are further The procedural details for establishing a session are further
described in Section 5.3. described in Section 5.3.
Upon completion of the process the DTLS Transport Model returns Upon completion of the process the DTLS Transport Model returns
status information and, if the process was successful the status information and, if the process was successful the
dtlsSessionID and other implementation-dependent data from DTLS are dtlsSessionID. Other implementation-dependent data from DTLS are
also returned. The dtlsSessionID is stored in an implementation- also returned. The dtlsSessionID is stored in an implementation-
dependent manner and tied to the tmSecurityData for future use of dependent manner and tied to the tmSecurityData for future use of
this session. this session.
4.4.2. DTLS Services for an Incoming Message 4.4.2. DTLS Services for an Incoming Message
When the DTLS Transport Model invokes the DTLS record layer to verify When the DTLS Transport Model invokes the DTLS record layer to verify
proper security for the incoming message, it must use the following proper security for the incoming message, it must use the following
ASI: ASI:
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service primitives are as follows: service primitives are as follows:
statusInformation: An indication of whether the process was statusInformation: An indication of whether the process was
successful or not. If not, then the status information will successful or not. If not, then the status information will
include the error indication provided by DTLS. include the error indication provided by DTLS.
dtlsSessionID: An implementation-dependent session identifier to dtlsSessionID: An implementation-dependent session identifier to
reference the specific DTLS session. How the DTLS session ID is reference the specific DTLS session. How the DTLS session ID is
obtained for each message is implementation-dependent. As an obtained for each message is implementation-dependent. As an
implementation hint, the DTLS Transport Model can examine incoming implementation hint, the DTLS Transport Model can examine incoming
messages to determine the source IP address and port number and messages to determine the source IP address, source port number,
use these values to look up the local DTLS session ID in the list destination IP address, and destination port number and use these
of active sessions. values to look up the local DTLS session ID in the list of active
sessions.
wholeDtlsMsg: The whole message as received on the wire. wholeDtlsMsg: The whole message as received on the wire.
wholeDtlsMsgLength: The length of the message as it was received on wholeDtlsMsgLength: The length of the message as it was received on
the wire. the wire.
incomingMessage: The whole SNMP message stripped of all DTLS privacy incomingMessage: The whole SNMP message stripped of all DTLS privacy
and integrity data. and integrity data.
incomingMessageLength: The length of the SNMP message stripped of incomingMessageLength: The length of the SNMP message stripped of
skipping to change at page 22, line 48 skipping to change at page 24, line 45
outgoingMessage: The outgoing message to send to DTLS for outgoingMessage: The outgoing message to send to DTLS for
encapsulation. encapsulation.
outgoingMessageLength: The length of the outgoing message. outgoingMessageLength: The length of the outgoing message.
4.5. Cached Information and References 4.5. Cached Information and References
When performing SNMP processing, there are two levels of state When performing SNMP processing, there are two levels of state
information that may need to be retained: the immediate state linking information that may need to be retained: the immediate state linking
a request-response pair, and potentially longer-term state relating a request-response pair, and potentially longer-term state relating
to transport and security. to transport and security. "Transport Subsystem for the Simple
Network Management Protocol" [I-D.ietf-isms-tmsm] defines general
The RFC3411 architecture uses caches to maintain the short-term requirements for caches and references.
message state, and uses references in the ASIs to pass this
information between subsystems.
This document defines the requirements for a cache to handle the
longer-term transport state information, using a tmStateReference
parameter to pass this information between subsystems.
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 being processed gets
discarded, the state related to that message SHOULD also be
discarded. If state information is available when a relationship
between engines is severed, such as the closing of a transport
session, the state information for that relationship SHOULD also be
discarded.
Since the contents of a cache are meaningful only within an
implementation, and not on-the-wire, the format of the cache and the
LCD are implementation-specific.
4.5.1. securityStateReference
The securityStateReference parameter is defined in RFC3411. Its
primary purpose is to provide a mapping between a request and the
corresponding response. This cache is not accessible to Transport
Models, and an entry is typically only retained for the lifetime of a
request-response pair of messages.
4.5.2. tmStateReference
For each transport session, information about the transport security
is stored in a cache. The tmStateReference parameter is used to pass
model-specific and mechanism-specific parameters between the
Transport subsystem and transport-aware Security Models.
The tmStateReference cache will typically remain valid for the
duration of the transport session, and hence may be used for several
messages.
Since this cache is only used within an implementation, and not on-
the-wire, the precise contents and format are implementation-
dependent. However, for interoperability between Transport Models
and transport-aware Security Models, entries in this cache must
include at least the following fields:
transportDomain
transportAddress
tmSecurityName
tmRequestedSecurityLevel
tmTransportSecurityLevel
tmSameSecurity
tmSessionID
4.5.2.1. Transport information
Information about the source of an incoming SNMP message is passed up
from the Transport subsystem as far as the Message Processing
subsystem. However these parameters are not included in the
processIncomingMsg ASI defined in RFC3411, and hence this information
is not directly available to the Security Model.
A transport-aware Security Model might wish to take account of the
transport protocol and originating address when authenticating the
request, and setting up the authorization parameters. It is
therefore necessary for the Transport Model to include this
information in the tmStateReference cache, so that it is accessible
to the Security Model.
o transportDomain: the transport protocol (and hence the Transport
Model) used to receive the incoming message
o transportAddress: the source of the incoming message.
The ASIs used for processing an outgoing message all include explicit
transportDomain and transportAddress parameters. The values within
the securityStateReference cache might override these parameters for
outgoing messages.
4.5.2.2. securityName
There are actually three distinct "identities" that can be identified
during the processing of an SNMP request over a secure transport:
o transport principal: the transport-authenticated identity, on
whose behalf the secure transport connection was (or should be)
established. This value is transport-, mechanism- and
implementation- specific, and is only used within a given
Transport Model.
o tmSecurityName: a human-readable name (in snmpAdminString format)
representing this transport identity. This value is transport-
and implementation-specific, and is only used (directly) by the
Transport and Security Models.
o securityName: a human-readable name (in snmpAdminString format)
representing the SNMP principal in a model-independent manner.
The transport principal may or may not be the same as the
tmSecurityName. Similarly, the tmSecurityName may or may not be the
same as the securityName as seen by the Application and Access
Control subsystems. In particular, a non-transport-aware Security
Model will ignore tmSecurityName completely when determining the SNMP
securityName.
However it is important that the mapping between the transport
principal and the SNMP securityName (for transport-aware Security
Models) is consistent and predictable, to allow configuration of
suitable access control and the establishment of transport
connections.
4.5.2.3. securityLevel
There are two distinct issues relating to security level as applied
to secure transports. For clarity, these are handled by separate
fields in the tmStateReference cache:
o tmTransportSecurityLevel: an indication from the Transport Model
of the level of security offered by this session. The Security
Model can use this to ensure that incoming messages were suitably
protected before acting on them.
o tmRequestedSecurityLevel: an indication from the Security Model of
the level of security required to be provided by the transport
protocol. The Transport Model can use this to ensure that
outgoing messages will not be sent over an insufficiently secure
session.
4.5.2.4. Session Information
For security reasons, if a secure transport session is closed between
the time a request message is received and the corresponding response
message is sent, then the response message SHOULD be discarded, even
if a new session has been established. The SNMPv3 WG decided that
this should be a SHOULD architecturally, and it is a security-model-
specific decision whether to REQUIRE this.
o tmSameSecurity: this flag is used by a transport-aware Security
Model to indicate whether the Transport Model MUST enforce this
restriction.
o tmSessionID: in order to verify whether the session has changed,
the Transport Model must be able to compare the session used to
receive the original request with the one to be used to send the
response. This typically requires some form of session
identifier. This value is only ever used by the Transport Model,
so the format and interpretation of this field are model-specific
and implementation-dependent.
When processing an outgoing message, if tmSameSecurity is true, then
the tmSessionID MUST match the current transport session, otherwise
the message MUST be discarded, and the dispatcher notified that
sending the message failed.
4.5.3. DTLS Transport Model Cached Information
For the DTLS Transport Model, the session state is maintained using
tmStateReference. Upon opening each DTLS session, the DTLS Transport
Model stores model- and mechanism-specific information about the
session in a cache, referenced by tmStateReference. An
implementation might store the contents of the cache in a Local
Configuration Datastore (LCD).
At a minimum, the following parameters are stored in the cache:
tmTransportDomain = Specified by the application tmSameSecurity =
boolean value set by the security model or false by default
tmTransportAddress = Specified by the application
tmRequestedSecurityLevel = ["noAuthNoPriv" | "authNoPriv" |
"authPriv" ] the security level requested by the application
tmSecurityLevel = ["noAuthNoPriv" | "authNoPriv" | "authPriv" ] the
security level of the established DTLS session
tmSecurityName = the security name associated with a principal
The tmStateReference cache is used to pass a reference to these
values between the DTLS Transport Model and the security model.
The DTLS Transport Model has the responsibility for releasing the
complete tmStateReference and deleting the associated information
when the session is destroyed.
4.5.3.1. Transport Information
The tmTransportDomain and tmTransportAddress identify the type and
address of the remote DTLS transport endpoint. The domain for
address types for DTLS sessions SHOULD be "snmpDTLSDomain" and the
address SHOULD be one that conforms to the details specified in the
"SnmpDTLSAddress" textual convention.
4.5.3.2. tmRequestedSecurityLevel
The tmRequestedSecurityLevel is the security level requested by the
application. This parameter is set in the cache by the security
model and used by DTLS Transport Model initiating a session to select
the appropriate cipher_suites and other configuration needed settings
for establishing the session. The DTLS Transport Model MUST ensure
that the actual security provided by the session (tmSecurityLevel) is
at least as high as the requested security level
(tmRequestedSecurityLevel).
4.5.3.3. tmSecurityLevel
The tmSecurityLevel is the actual security level of the established
session. See Section 3.1.2 for more detail about security levels.
How the chosen cipher_suites and other DTLS session parameters are
translated into a security level at the DTLS Transport Model is
implementation dependent and/or policy specific. Implementations
MUST NOT use NULL algorithms for fulfilling authentication or
encryption needs indicated by the tmSecurityLevel.
4.5.3.4. tmSecurityName
The tmSecurityName is the name of the principal on whose behalf the
message is being sent. This field is set via the mapping defined in
the dtlstmCertificateToSNTable when mapping incoming client
connection certificates to a tmSecurityName. For outgoing
connections, the application will specify the value that should be
placed in this field (possibly by extracting it from the SNMP-TARGET-
MIB's snmpTargetParamsSecurityName value).
4.5.4. Transport Model LCD 4.5.1. DTLS Transport Model Cached Information
Implementations may store DTLS-specific and model-specific The DTLSTM has no specific responsibilities regarding the cached
information in a LCD. The DTLS session ID is one such parameter that information beyond those discussed in "Transport Subsystem for the
could be stored in the LCD. When messages are to be routed for Simple Network Management Protocol" [I-D.ietf-isms-tmsm]
encapsulation or for integrity verification and decryption the
message and the DTLS session ID must be passed to the DTLS transport
layer for processing. Therefore, the DTLS Transport Model MUST
maintain a one-to-one mapping between the DTLS session ID and the
tmStateReference cache entry for that session. Implementations will
need to store the DTLS session ID in the tmStateReference cache to
simplify the procedure.
5. Elements of Procedure 5. Elements of Procedure
Abstract service interfaces have been defined by RFC 3411 to describe Abstract service interfaces have been defined by RFC 3411 to describe
the conceptual data flows between the various subsystems within an the conceptual data flows between the various subsystems within an
SNMP entity. The DTLSTM uses some of these conceptual data flows SNMP entity. The DTLSTM uses some of these conceptual data flows
when communicating between subsystems. These RFC 3411-defined data when communicating between subsystems. These RFC 3411-defined data
flows are referred to here as public interfaces. flows are referred to here as public interfaces.
To simplify the elements of procedure, the release of state To simplify the elements of procedure, the release of state
skipping to change at page 28, line 39 skipping to change at page 25, line 45
Transport Model when it receives a DTLS protected packet. The steps Transport Model when it receives a DTLS protected packet. The steps
are broken into two different sections. The first section describes are broken into two different sections. The first section describes
the needed steps for de-multiplexing multiple DTLS sessions and the the needed steps for de-multiplexing multiple DTLS sessions and the
second section describes the steps which are specific to transport second section describes the steps which are specific to transport
processing once the DTLS processing has been completed. processing once the DTLS processing has been completed.
5.1.1. DTLS Processing for Incoming Messages 5.1.1. DTLS Processing for Incoming Messages
DTLS is significantly different in terms of session handling than DTLS is significantly different in terms of session handling than
SSH, TLS or other TCP-based session streams. The DTLS protocol, SSH, TLS or other TCP-based session streams. The DTLS protocol,
which is UDP-based, does not have a session identifier that allows which is datagram-based, does not have a session identifier when run
implementations to determine through which session a packet is over UDP that allows implementations to determine through which
arriving like TCP-based streams have. Thus, a process for de- session a packet is arriving like SCTP-based and TCP-based streams
multiplexing sessions must be incorporated into the procedures for an have. Thus, a process for de-multiplexing sessions when used over
incoming message. The steps in this section describe how this can be UDP must be incorporated into the procedures for an incoming message.
accomplished, although any implementation dependent method for doing The steps in this section describe how this can be accomplished,
so should be suitable as long as the results are consistently although any implementation dependent method for doing so should be
deterministic. The important results from the steps in this section suitable as long as the results are consistently deterministic. The
are the transportDomain, the transportAddress, the wholeMessage, the important results from the steps in this section are the
transportDomain, the transportAddress, the wholeMessage, the
wholeMessageLength, and a unique implementation-dependent session wholeMessageLength, and a unique implementation-dependent session
identifier. identifier.
This procedure assumes that upon session establishment, an entry in a This procedure assumes that upon session establishment, an entry in a
local transport mapping table is created in the Transport Model's local transport mapping table is created in the Transport Model's
LCD. This transport mapping table entry should be able to map a LCD. This transport mapping table entry should be able to map a
unique combination of the remote address, remote port number, local unique combination of the remote address, remote port number, local
address and local port number to a implementation-dependent address and local port number to a implementation-dependent
dtlsSessionID. dtlsSessionID.
skipping to change at page 30, line 14 skipping to change at page 27, line 24
5.1.2. Transport Processing for Incoming Messages 5.1.2. Transport Processing for Incoming Messages
The procedures in this section describe how the DTLS Transport should The procedures in this section describe how the DTLS Transport should
process messages that have already been properly extracted from the process messages that have already been properly extracted from the
DTLS stream, as described in Section 5.1.1. DTLS stream, as described in Section 5.1.1.
1) Create a tmStateReference cache for the subsequent reference and 1) Create a tmStateReference cache for the subsequent reference and
assign the following values within it: assign the following values within it:
tmTransportDomain = snmpDTLSDomain tmTransportDomain = snmpDTLSUDPDomain or snmpDTLSSCTPDomain as
appropriate.
tmTransportAddress = The address the message originated from, tmTransportAddress = The address the message originated from,
determined in an implementation dependent way. determined in an implementation dependent way.
tmSecurityLevel = The derived tmSecurityLevel for the session, tmSecurityLevel = The derived tmSecurityLevel for the session,
as discussed in Section 3.1.2 and Section 5.3. as discussed in Section 3.1.2 and Section 5.3.
tmSecurityName = The derived tmSecurityName for the session as tmSecurityName = The derived tmSecurityName for the session as
discussed in and Section 5.3. discussed in and Section 5.3. This value MUST be constant
during the lifetime of the DTLS session.
tmSessionID = The dtlsSessionID, which MUST be A unique session tmSessionID = The dtlsSessionID, which MUST be A unique session
identifier for this DTLS session. The contents and format of identifier for this DTLS session. The contents and format of
this identifier are implementation dependent as long as it is this identifier are implementation dependent as long as it is
unique to the session. A session identifier MUST NOT be unique to the session. A session identifier MUST NOT be
reused until all references to it are no longer in use. The reused until all references to it are no longer in use. The
tmSessionID is equal to the dtlsSessionID discussed in tmSessionID is equal to the dtlsSessionID discussed in
Section 5.1.1. tmSessionID refers to the session identifier Section 5.1.1. tmSessionID refers to the session identifier
when stored in the tmStateReference and dtlsSessionID refers when stored in the tmStateReference and dtlsSessionID refers
to the session identifier when stored in the LCD. They MUST to the session identifier when stored in the LCD. They MUST
skipping to change at page 31, line 36 skipping to change at page 28, line 49
2) If tmSameSecurity is true and either tmSessionID is undefined or 2) If tmSameSecurity is true and either tmSessionID is undefined or
refers to a session that is no longer open then increment the refers to a session that is no longer open then increment the
dtlstmSessionNoAvailableSessions counter, discard the message and dtlstmSessionNoAvailableSessions counter, discard the message and
return the error indication in the statusInformation. Processing return the error indication in the statusInformation. Processing
of this message stops. of this message stops.
3) If tmSameSecurity is false and tmSessionID refers to a session 3) If tmSameSecurity is false and tmSessionID refers to a session
that is no longer available then an implementation SHOULD open a that is no longer available then an implementation SHOULD open a
new session using the openSession() ASI as described below in new session using the openSession() ASI as described below in
step 3b. An implementation MAY choose to return an error to the step 4b. An implementation MAY choose to return an error to the
calling module. calling module.
4) If tmSessionID is undefined, then use tmTransportAddress, 4) If tmSessionID is undefined, then use tmTransportAddress,
tmSecurityName and tmRequestedSecurityLevel to see if there is a tmSecurityName and tmRequestedSecurityLevel to see if there is a
corresponding entry in the LCD suitable to send the message over. corresponding entry in the LCD suitable to send the message over.
3a) If there is a corresponding LCD entry, then this session 4a) If there is a corresponding LCD entry, then this session
will be used to send the message. will be used to send the message.
3b) If there is not a corresponding LCD entry, then open a 4b) If there is not a corresponding LCD entry, then open a
session using the openSession() ASI (discussed further in session using the openSession() ASI (discussed further in
Section 4.4.1). Implementations MAY wish to offer message Section 4.4.1). Implementations MAY wish to offer message
buffering to prevent redundant openSession() calls for the buffering to prevent redundant openSession() calls for the
same cache entry. If an error is returned from same cache entry. If an error is returned from
OpenSession(), then discard the message, increment the OpenSession(), then discard the message, increment the
dtlstmSessionOpenErrors, and return an error indication to dtlstmSessionOpenErrors, and return an error indication to
the calling module. the calling module.
5) Using either the session indicated by the tmSessionID if there 5) Using either the session indicated by the tmSessionID if there
was one or the session resulting in the previous step, pass the was one or the session resulting in the previous step, pass the
skipping to change at page 32, line 33 skipping to change at page 29, line 48
The following sections describe the procedures followed by a DTLS The following sections describe the procedures followed by a DTLS
Transport Model when establishing a session as a Command Generator, a Transport Model when establishing a session as a Command Generator, a
Notification Originator or as part of a Proxy Forwarder. Notification Originator or as part of a Proxy Forwarder.
The following describes the procedure to follow to establish a The following describes the procedure to follow to establish a
session between SNMP engines to exchange SNMP messages. This process session between SNMP engines to exchange SNMP messages. This process
is followed by any SNMP engine establishing a session for subsequent is followed by any SNMP engine establishing a session for subsequent
use. use.
This MAY done automatically for SNMP messages which are not Response This MAY be done automatically for SNMP messages which are not
or Report messages. Response or Report messages.
DTLS provides no explicit manner for transmitting an identity the DTLS provides no explicit manner for transmitting an identity the
client wishes to connect to during or prior to key exchange to client wishes to connect to during or prior to key exchange to
facilitate certificate selection at the server (e.g. at a facilitate certificate selection at the server (e.g. at a
Notification Receiver). I.E., there is no available mechanism for Notification Receiver). I.E., there is no available mechanism for
sending notifications to a specific principal at a given UDP/port sending notifications to a specific principal at a given UDP or SCTP
combination. Therefore, implementations MAY support responding with port. Therefore, implementations MAY support responding with
multiple identities using separate UDP port numbers to indicate the multiple identities using separate UDP or SCTP port numbers to
desired principal or some other implementation-dependent solution. indicate the desired principal or some other implementation-dependent
solution.
1) The client selects the appropriate certificate and cipher_suites 1) The client selects the appropriate certificate and cipher_suites
for the key agreement based on the tmSecurityName and the for the key agreement based on the tmSecurityName and the
tmRequestedSecurityLevel for the session. For sessions being tmRequestedSecurityLevel for the session. For sessions being
established as a result of a SNMP-TARGET-MIB based operation, the established as a result of a SNMP-TARGET-MIB based operation, the
certificate will potentially have been identified via the certificate will potentially have been identified via the
dtlstmParamsTable mapping and the cipher_suites will have to be dtlstmParamsTable mapping and the cipher_suites will have to be
taken from system-wide or implementation-specific configuration. taken from system-wide or implementation-specific configuration.
Otherwise, the certificate and appropriate cipher_suites will Otherwise, the certificate and appropriate cipher_suites will
need to be passed to the openSession() ASI as supplemental need to be passed to the openSession() ASI as supplemental
skipping to change at page 36, line 13 skipping to change at page 33, line 27
This MIB module is for managing DTLS Transport Model information. This MIB module is for managing DTLS Transport Model information.
6.5.1. MIB Modules Required for IMPORTS 6.5.1. MIB Modules Required for IMPORTS
The following MIB module imports items from SNMPV2-SMI [RFC2578], The following MIB module imports items from SNMPV2-SMI [RFC2578],
SNMPV2-TC [RFC2579], SNMP-FRAMEWORK-MIB [RFC3411], SNMP-TARGET-MIB SNMPV2-TC [RFC2579], SNMP-FRAMEWORK-MIB [RFC3411], SNMP-TARGET-MIB
[RFC3413] and SNMP-CONF [RFC2580]. [RFC3413] and SNMP-CONF [RFC2580].
7. MIB Module Definition 7. MIB Module Definition
DTLSTM-MIB DEFINITIONS ::= BEGIN DTLSTM-MIB DEFINITIONS ::= BEGIN
IMPORTS IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, MODULE-IDENTITY, OBJECT-TYPE,
OBJECT-IDENTITY, snmpModules, snmpDomains, OBJECT-IDENTITY, snmpModules, snmpDomains,
Counter32, Unsigned32 Counter32, Unsigned32
FROM SNMPv2-SMI FROM SNMPv2-SMI
TEXTUAL-CONVENTION, TimeStamp, RowStatus, StorageType TEXTUAL-CONVENTION, TimeStamp, RowStatus, StorageType
FROM SNMPv2-TC FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP MODULE-COMPLIANCE, OBJECT-GROUP
FROM SNMPv2-CONF FROM SNMPv2-CONF
SnmpAdminString SnmpAdminString
FROM SNMP-FRAMEWORK-MIB FROM SNMP-FRAMEWORK-MIB
snmpTargetParamsEntry snmpTargetParamsEntry
FROM SNMP-TARGET-MIB FROM SNMP-TARGET-MIB
; ;
dtlstmMIB MODULE-IDENTITY dtlstmMIB MODULE-IDENTITY
LAST-UPDATED "200807070000Z" LAST-UPDATED "200807070000Z"
ORGANIZATION " " ORGANIZATION " "
CONTACT-INFO "WG-EMail: CONTACT-INFO "WG-EMail:
Subscribe: Subscribe:
Chairs: Chairs:
Co-editors: Co-editors:
" "
DESCRIPTION "The DTLS Transport Model MIB DESCRIPTION "The DTLS Transport Model MIB
Copyright (C) The IETF Trust (2008). This Copyright (C) The IETF Trust (2008). This
version of this MIB module is part of RFC XXXX; version of this MIB module is part of RFC XXXX;
see the RFC itself for full legal notices." see the RFC itself for full legal notices."
-- NOTE to RFC editor: replace XXXX with actual RFC number
-- for this document and remove this note
REVISION "200807070000Z" REVISION "200807070000Z"
DESCRIPTION "The initial version, published in RFC XXXX." DESCRIPTION "The initial version, published in RFC XXXX."
-- NOTE to RFC editor: replace XXXX with actual RFC number
-- for this document and remove this note
::= { snmpModules xxxx } ::= { snmpModules xxxx }
-- RFC Ed.: replace xxxx with IANA-assigned number and
-- remove this note
-- ************************************************
-- subtrees of the SNMP-DTLS-TM-MIB
-- ************************************************
dtlstmNotifications OBJECT IDENTIFIER ::= { dtlstmMIB 0 } dtlstmNotifications OBJECT IDENTIFIER ::= { dtlstmMIB 0 }
dtlstmObjects OBJECT IDENTIFIER ::= { dtlstmMIB 1 } dtlstmObjects OBJECT IDENTIFIER ::= { dtlstmMIB 1 }
dtlstmConformance OBJECT IDENTIFIER ::= { dtlstmMIB 2 } dtlstmConformance OBJECT IDENTIFIER ::= { dtlstmMIB 2 }
-- ************************************************
-- Objects
-- ************************************************
snmpDTLSDomain OBJECT-IDENTITY snmpDTLSUDPDomain OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The SNMP over DTLS transport domain. The corresponding "The SNMP over DTLS transport domain. The corresponding
transport address is of type SnmpDTLSAddress. transport address is of type SnmpDTLSUDPAddress.
When an SNMP entity uses the snmpDTLSDomain transport When an SNMP entity uses the snmpDTLSUDPDomain transport
model, it must be capable of accepting messages up to model, it must be capable of accepting messages up to
the maximum MTU size for an interface it supports, minus the the maximum MTU size for an interface it supports, minus the
needed IP, UDP, DTLS and other protocol overheads. needed IP, UDP, DTLS and other protocol overheads.
The securityName prefix to be associated with the The securityName prefix to be associated with the
snmpDTLSDomain is 'dtls'. This prefix may be used by snmpDTLSUDPDomain is 'dudp'. This prefix may be used by
security models or other components to identify what secure security models or other components to identify what secure
transport infrastructure authenticated a securityName." transport infrastructure authenticated a securityName."
::= { snmpDomains yy } ::= { snmpDomains yy }
-- RFC Ed.: replace yy with IANA-assigned number and
-- remove this note
-- RFC Ed.: replace 'dudp' with the actual IANA assigned prefix string
-- if 'dtls' is not assigned to this document.
snmpDTLSSCTPDomain OBJECT-IDENTITY
STATUS current
DESCRIPTION
"The SNMP over DTLS transport domain. The corresponding
transport address is of type SnmpDTLSSCTPAddress.
SnmpDTLSAddress ::= TEXTUAL-CONVENTION When an SNMP entity uses the snmpDTLSSCTPDomain transport
DISPLAY-HINT "1a" model, it must be capable of accepting messages up to
STATUS current the maximum MTU size for an interface it supports, minus the
DESCRIPTION needed IP, SCTP, DTLS and other protocol overheads.
"Represents a UDP connection address for an IPv4 address, an
IPv6 address or an ASCII encoded host name and port number.
The hostname must be encoded in ASCII, as specified in RFC3490 The securityName prefix to be associated with the
(Internationalizing Domain Names in Applications) followed by snmpDTLSSCTPDomain is 'dsct'. This prefix may be used by
a colon ':' (ASCII character 0x3A) and a decimal port number security models or other components to identify what secure
in ASCII. The name SHOULD be fully qualified whenever transport infrastructure authenticated a securityName."
possible.
An IPv4 address must be a dotted decimal format followed by a ::= { snmpDomains zz }
colon ':' (ASCII character 0x3A) and a decimal port number in
ASCII.
An IPv6 address must be a colon separated format, surrounded -- RFC Ed.: replace zz with IANA-assigned number and
by square brackets (ASCII characters 0x5B and 0x5D), followed -- remove this note
by a colon ':' (ASCII character 0x3A) and a decimal port
number in ASCII.
Values of this textual convention may not be directly usable -- RFC Ed.: replace 'dsct' with the actual IANA assigned prefix string
as transport-layer addressing information, and may require -- if 'dtls' is not assigned to this document.
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 SnmpDTLSUDPAddress ::= TEXTUAL-CONVENTION
have snmpDTLSAddress values must fully describe how (and when) DISPLAY-HINT "1a"
such names are to be resolved to IP addresses and vice versa. STATUS current
DESCRIPTION
"Represents a UDP connection address for an IPv4 address, an
IPv6 address or an ASCII encoded host name and port number.
This textual convention SHOULD NOT be used directly in object The hostname must be encoded in ASCII, as specified in RFC3490
definitions since it restricts addresses to a specific (Internationalizing Domain Names in Applications) followed by
format. However, if it is used, it MAY be used either on its a colon ':' (ASCII character 0x3A) and a decimal port number
own or in conjunction with TransportAddressType or in ASCII. The name SHOULD be fully qualified whenever
TransportDomain as a pair. possible.
When this textual convention is used as a syntax of an index An IPv4 address must be a dotted decimal format followed by a
object, there may be issues with the limit of 128 colon ':' (ASCII character 0x3A) and a decimal port number in
sub-identifiers specified in SMIv2, STD 58. It is RECOMMENDED ASCII.
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."
SYNTAX OCTET STRING (SIZE (1..255))
X509IdentifierHashType ::= TEXTUAL-CONVENTION An IPv6 address must be a colon separated format, surrounded
STATUS current by square brackets (ASCII characters 0x5B and 0x5D), followed
DESCRIPTION by a colon ':' (ASCII character 0x3A) and a decimal port
"Identifies a hashing algorithm type that will be used for number in ASCII.
identifying an X.509 certificate.
The md5(1) value SHOULD NOT be used." Values of this textual convention may not be directly usable
SYNTAX INTEGER { md5(1), sha1(2), sha256(3) } 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).
X509IdentifierHash ::= TEXTUAL-CONVENTION The DESCRIPTION clause of TransportAddress objects that may
STATUS current have snmpDTLSUDPAddress values must fully describe how (and
DESCRIPTION when) such names are to be resolved to IP addresses and vice
"A hash value that uniquely identifies a certificate within a versa.
systems local certificate store. The length of the value
stored in an object of type X509IdentifierHash is dependent on
the hashing algorithm that produced the hash.
MIB structures making use of this textual convention should This textual convention SHOULD NOT be used directly in object
have an accompanying object of type X509IdentifierHashType. definitions since it restricts addresses to a specific
" format. However, if it is used, it MAY be used either on its
SYNTAX OCTET STRING 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."
SYNTAX OCTET STRING (SIZE (1..255))
dtlstmSession OBJECT IDENTIFIER ::= { dtlstmObjects 1 } SnmpDTLSSCTPAddress ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1a"
STATUS current
DESCRIPTION
"Represents a SCTP connection address for an IPv4 address, an
IPv6 address or an ASCII encoded host name and port number.
dtlstmSessionOpens OBJECT-TYPE The hostname must be encoded in ASCII, as specified in RFC3490
SYNTAX Counter32 (Internationalizing Domain Names in Applications) followed by
MAX-ACCESS read-only a colon ':' (ASCII character 0x3A) and a decimal port number
STATUS current in ASCII. The name SHOULD be fully qualified whenever
DESCRIPTION possible.
"The number of times an openSession() request has been
executed as an SSH client, whether it succeeded or failed."
::= { dtlstmSession 1 }
dtlstmSessionCloses OBJECT-TYPE An IPv4 address must be a dotted decimal format followed by a
SYNTAX Counter32 colon ':' (ASCII character 0x3A) and a decimal port number in
MAX-ACCESS read-only ASCII.
STATUS current
DESCRIPTION
"The number of times a closeSession() request has been
executed as an SSH client, whether it succeeded or failed."
::= { dtlstmSession 2 }
dtlstmSessionOpenErrors OBJECT-TYPE An IPv6 address must be a colon separated format, surrounded
SYNTAX Counter32 by square brackets (ASCII characters 0x5B and 0x5D), followed
MAX-ACCESS read-only by a colon ':' (ASCII character 0x3A) and a decimal port
STATUS current number in ASCII.
DESCRIPTION
"The number of times an openSession() request failed to open a
session as a SSH client, for any reason."
::= { dtlstmSession 3 }
dtlstmSessionNoAvailableSessions OBJECT-TYPE Values of this textual convention may not be directly usable
SYNTAX Counter32 as transport-layer addressing information, and may require
MAX-ACCESS read-only run-time resolution. As such, applications that write them
STATUS current must be prepared for handling errors if such values are not
DESCRIPTION supported, or cannot be resolved (if resolution occurs at the
"The number of times an outgoing message was dropped because time of the management operation).
the session associated with the passed tmStateReference was no
longer (or was never) available."
::= { dtlstmSession 4 }
dtlstmSessionInvalidClientCertificates OBJECT-TYPE The DESCRIPTION clause of TransportAddress objects that may
SYNTAX Counter32 have snmpDTLSSCTPAddress values must fully describe how (and
MAX-ACCESS read-only when) such names are to be resolved to IP addresses and vice
STATUS current versa.
DESCRIPTION
"The number of times an incoming session was not established
on an SSH server because the presented client certificate was
invalid. Reasons for invalidation includes, but is not
limited to, crypographic validation failures and lack of a
suitable mapping row in the dtlstmCertificateToSNTable."
::= { dtlstmSession 5 }
dtlstmSessionInvalidServerCertificates OBJECT-TYPE This textual convention SHOULD NOT be used directly in object
SYNTAX Counter32 definitions since it restricts addresses to a specific
MAX-ACCESS read-only format. However, if it is used, it MAY be used either on its
STATUS current own or in conjunction with TransportAddressType or
DESCRIPTION TransportDomain as a pair.
"The number of times an outgoing session was not established
on an SSH client because the presented server certificate was
invalid. Reasons for invalidation includes, but is not
limited to, crypographic validation failures and an unexpected
presented certificate identity."
::= { dtlstmSession 6 }
dtlstmDTLSProtectionErrors OBJECT-TYPE When this textual convention is used as a syntax of an index
SYNTAX Counter32 object, there may be issues with the limit of 128
MAX-ACCESS read-only sub-identifiers specified in SMIv2, STD 58. It is RECOMMENDED
STATUS current that all MIB documents using this textual convention make
DESCRIPTION explicit any limitations on index component lengths that
"The number of times DTLS processing resulted in a message management software must observe. This may be done either by
being discarded because it failed its integrity test, including SIZE constraints on the index components or by
decryption processing or other DTLS processing." specifying applicable constraints in the conceptual row
DESCRIPTION clause or in the surrounding documentation."
SYNTAX OCTET STRING (SIZE (1..255))
::= { dtlstmSession 7 } X509IdentifierHashType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Identifies a hashing algorithm type that will be used for
identifying an X.509 certificate.
The md5(1) value SHOULD NOT be used."
SYNTAX INTEGER { md5(1), sha1(2), sha256(3) }
dtlstmConfig OBJECT IDENTIFIER ::= { dtlstmObjects 2 } X509IdentifierHash ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"A hash value that uniquely identifies a certificate within a
systems local certificate store. The length of the value
stored in an object of type X509IdentifierHash is dependent on
the hashing algorithm that produced the hash.
MIB structures making use of this textual convention should
have an accompanying object of type X509IdentifierHashType.
"
SYNTAX OCTET STRING
dtlstmCertificateMapping OBJECT IDENTIFIER ::= { dtlstmConfig 1 } -- The dtlstmSession Group
dtlstmCertificateToSNCount OBJECT-TYPE dtlstmSession OBJECT IDENTIFIER ::= { dtlstmObjects 1 }
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A count of the number of entries in the
dtlstmCertificateToSNTable"
::= { dtlstmCertificateMapping 1 }
dtlstmCertificateToSNTableLastChanged OBJECT-TYPE dtlstmSessionOpens OBJECT-TYPE
SYNTAX TimeStamp SYNTAX Counter32
MAX-ACCESS read-only MAX-ACCESS read-only
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The value of sysUpTime.0 when the dtlstmCertificateToSNTable "The number of times an openSession() request has been
was last modified through any means, or 0 if it has not been executed as an SSH client, whether it succeeded or failed."
modified since the command responder was started." ::= { dtlstmSession 1 }
::= { dtlstmCertificateMapping 2 }
dtlstmCertificateToSNTable OBJECT-TYPE dtlstmSessionCloses OBJECT-TYPE
SYNTAX SEQUENCE OF DtlstmCertificateToSNEntry SYNTAX Counter32
MAX-ACCESS not-accessible MAX-ACCESS read-only
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"A table listing the X.509 certificates known to the entity "The number of times a closeSession() request has been
and the associated method for determining the SNMPv3 security executed as an SSH client, whether it succeeded or failed."
name from a certificate. ::= { dtlstmSession 2 }
On an incoming DTLS/SNMP connection the client's presented dtlstmSessionOpenErrors OBJECT-TYPE
certificate should be examined and validated based on an SYNTAX Counter32
established trusted CA certificate or self-signed public MAX-ACCESS read-only
certificate. This table does not provide a mechanism for STATUS current
uploading the certificates as that is expected to occur DESCRIPTION
through an out-of-band transfer. "The number of times an openSession() request failed to open a
session as a SSH client, for any reason."
::= { dtlstmSession 3 }
Once the authenticity of the certificate has been verified, dtlstmSessionNoAvailableSessions OBJECT-TYPE
this table can be consulted to determine the appropriate SYNTAX Counter32
securityName to identify the remote connection. This is done MAX-ACCESS read-only
by comparing the issuer's fingerprint hash type and value and STATUS current
the certificate's fingerprint hash type and value against the DESCRIPTION
dtlstmCertHashType and dtlstmCertHashValue values in each "The number of times an outgoing message was dropped because
entry of this table. If a matching entry is found then the the session associated with the passed tmStateReference was no
securityName is selected based on the dtlstmCertMapType, longer (or was never) available."
dtlstmCertHashType, dtlstmCertHashValue and ::= { dtlstmSession 4 }
dtlstmCertSecurityName fields and the resulting securityName
is used to identify the other side of the DTLS connection.
This table should be treated as an ordered list of mapping dtlstmSessionInvalidClientCertificates OBJECT-TYPE
rules to check. The first mapping rule appropriately matching SYNTAX Counter32
a certificate in the local certificate store with a MAX-ACCESS read-only
corresponding hash type (dtlstmCertHashType) and hash value STATUS current
(dtlstmCertHashValue) will be used to perform the mapping from DESCRIPTION
X.509 certificate values to a securityName. If, after a "The number of times an incoming session was not established
matching row is found but the mapping can not succeed for some on an SSH server because the presented client certificate was
other reason then further attempts to perform the mapping MUST invalid. Reasons for invalidation includes, but is not
NOT be taken. For example, if the entry being checked limited to, crypographic validation failures and lack of a
contains a dtlstmCertMapType of bySubjectAltName(2) and an suitable mapping row in the dtlstmCertificateToSNTable."
incoming connection uses a certificate with an issuer ::= { dtlstmSession 5 }
certificate matching the dtlstmCertHashType and
dtlstmCertHashValue fields but the connecting certificate does
not contain a subjectAltName field then the lookup operation
must be treated as a failure. No further rows are examined for
other potential mappings.
Missing values of dtlstmCertID are acceptable and dtlstmSessionInvalidServerCertificates OBJECT-TYPE
implementations should treat missing entries as a failed match SYNTAX Counter32
and should continue to the next highest numbered row. E.G., MAX-ACCESS read-only
the table may legally contain only two rows with dtlstmCertID STATUS current
values of 10 and 20. DESCRIPTION
"The number of times an outgoing session was not established
on an SSH client because the presented server certificate was
invalid. Reasons for invalidation includes, but is not
limited to, crypographic validation failures and an unexpected
presented certificate identity."
::= { dtlstmSession 6 }
Users are encouraged to make use of certificates with dtlstmDTLSProtectionErrors OBJECT-TYPE
subjectAltName fields that can be used as securityNames so SYNTAX Counter32
that a single root CA certificate can allow all child MAX-ACCESS read-only
certificate's subjectAltName to map directly to a securityName STATUS current
via a 1:1 transformation. However, this table is flexible DESCRIPTION
enough to allow for situations where existing deployed "The number of times DTLS processing resulted in a message
certificate infrastructures do not provide adequate being discarded because it failed its integrity test,
subjectAltName values for use as SNMPv3 securityNames. decryption processing or other DTLS processing."
Certificates may also be mapped to securityNames using the ::= { dtlstmSession 7 }
CommonName portion of the Subject field which is also a
scalable method of mapping certificate components to
securityNames. Finally, direct mapping from each individual
certificate fingerprint to a securityName is possible but
requires one entry in the table per securityName."
::= { dtlstmCertificateMapping 3 }
dtlstmCertificateToSNEntry OBJECT-TYPE -- Configuration Objects
SYNTAX DtlstmCertificateToSNEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A row in the dtlstmCertificateToSNTable that specifies a
mapping for an incoming DTLS certificate to a securityName to
use for the connection."
INDEX { dtlstmCertID }
::= { dtlstmCertificateToSNTable 1 }
DtlstmCertificateToSNEntry ::= SEQUENCE { dtlstmConfig OBJECT IDENTIFIER ::= { dtlstmObjects 2 }
dtlstmCertID Unsigned32,
dtlstmCertHashType X509IdentifierHashType,
dtlstmCertHashValue X509IdentifierHash,
dtlstmCertMapType INTEGER,
dtlstmCertSecurityName SnmpAdminString,
dtlstmCertStorageType StorageType,
dtlstmCertRowStatus RowStatus
}
dtlstmCertID OBJECT-TYPE -- Certificate mapping
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique arbitrary number index for a given certificate
entry."
::= { dtlstmCertificateToSNEntry 1 }
dtlstmCertHashType OBJECT-TYPE dtlstmCertificateMapping OBJECT IDENTIFIER ::= { dtlstmConfig 1 }
SYNTAX X509IdentifierHashType dtlstmCertificateToSNCount OBJECT-TYPE
MAX-ACCESS read-create SYNTAX Unsigned32
STATUS current MAX-ACCESS read-only
DESCRIPTION STATUS current
"The hash algorithm to use when applying a hash to a X.509 DESCRIPTION
certificate for purposes of referring to it from the "A count of the number of entries in the
dtlstmCertHashValue column. dtlstmCertificateToSNTable"
::= { dtlstmCertificateMapping 1 }
The md5(1) value SHOULD NOT be used." dtlstmCertificateToSNTableLastChanged OBJECT-TYPE
DEFVAL { sha256 } SYNTAX TimeStamp
::= { dtlstmCertificateToSNEntry 2 } MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime.0 when the dtlstmCertificateToSNTable
was last modified through any means, or 0 if it has not been
modified since the command responder was started."
::= { dtlstmCertificateMapping 2 }
dtlstmCertHashValue OBJECT-TYPE dtlstmCertificateToSNTable OBJECT-TYPE
SYNTAX X509IdentifierHash SYNTAX SEQUENCE OF DtlstmCertificateToSNEntry
MAX-ACCESS read-create MAX-ACCESS not-accessible
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"A cryptographic hash of a X.509 certificate. The use of this "A table listing the X.509 certificates known to the entity
hash is dictated by the dtlstmCertMapType column. and the associated method for determining the SNMPv3 security
" name from a certificate.
::= { dtlstmCertificateToSNEntry 3 }
dtlstmCertMapType OBJECT-TYPE On an incoming DTLS/SNMP connection the client's presented
SYNTAX INTEGER { specified(1), bySubjectAltName(2), byCN(3) } certificate should be examined and validated based on an
MAX-ACCESS read-create established trusted CA certificate or self-signed public
STATUS current certificate. This table does not provide a mechanism for
DESCRIPTION uploading the certificates as that is expected to occur
"The mapping type used to obtain the securityName from the through an out-of-band transfer.
certificate. The possible values of use and their usage
methods are defined as follows:
specified(1): The securityName that should be used locally to Once the authenticity of the certificate has been verified,
identify the remote entity is directly specified this table can be consulted to determine the appropriate
in the dtlstmCertSecurityName column from this securityName to identify the remote connection. This is done
table. The dtlstmCertHashValue MUST refer to a by comparing the issuer's fingerprint hash type and value and
X.509 client certificate that will be mapped the certificate's fingerprint hash type and value against the
directly to the securityName specified in the dtlstmCertHashType and dtlstmCertHashValue values in each
dtlstmCertSecurityName column. entry of this table. If a matching entry is found then the
securityName is selected based on the dtlstmCertMapType,
dtlstmCertHashType, dtlstmCertHashValue and
dtlstmCertSecurityName fields and the resulting securityName
is used to identify the other side of the DTLS connection.
bySubjectAltName(2): This table should be treated as an ordered list of mapping
The securityName that should be used locally to rules to check. The first mapping rule appropriately matching
identify the remote entity should be taken from a certificate in the local certificate store with a
the subjectAltName portion of the X.509 corresponding hash type (dtlstmCertHashType) and hash value
certificate. The dtlstmCertHashValue MUST refer (dtlstmCertHashValue) will be used to perform the mapping from
to a trust anchor certificate that is X.509 certificate values to a securityName. If, after a
responsible for issuing certificates with matching row is found but the mapping can not succeed for some
carefully controlled subjectAltName fields. other reason then further attempts to perform the mapping MUST
NOT be taken. For example, if the entry being checked
contains a dtlstmCertMapType of bySubjectAltName(2) and an
incoming connection uses a certificate with an issuer
certificate matching the dtlstmCertHashType and
dtlstmCertHashValue fields but the connecting certificate does
not contain a subjectAltName field then the lookup operation
must be treated as a failure. No further rows are examined for
other potential mappings.
byCN(3): The securityName that should be used locally to Missing values of dtlstmCertID are acceptable and
identify the remote entity should be taken from implementations should treat missing entries as a failed match
the CommonName portion of the Subject field from and should continue to the next highest numbered row. E.G.,
the X.509 certificate. The dtlstmCertHashValue the table may legally contain only two rows with dtlstmCertID
MUST refer to a trust anchor certificate that is values of 10 and 20.
responsible for issuing certificates with
carefully controlled CommonName fields."
DEFVAL { specified }
::= { dtlstmCertificateToSNEntry 4 }
dtlstmCertSecurityName OBJECT-TYPE Users are encouraged to make use of certificates with
SYNTAX SnmpAdminString (SIZE(0..32)) subjectAltName fields that can be used as securityNames so
MAX-ACCESS read-create that a single root CA certificate can allow all child
STATUS current certificate's subjectAltName to map directly to a securityName
DESCRIPTION via a 1:1 transformation. However, this table is flexible
"The securityName that the session should use if the enough to allow for situations where existing deployed
dtlstmCertMapType is set to specified(1), otherwise the value certificate infrastructures do not provide adequate
in this column should be ignored. If dtlstmCertMapType is set subjectAltName values for use as SNMPv3 securityNames.
to specifed(1) and this column contains a zero-length string Certificates may also be mapped to securityNames using the
(which is not a legal securityName value) this row is CommonName portion of the Subject field which is also a
effectively disabled and the match will not be considered scalable method of mapping certificate components to
successful." securityNames. Finally, direct mapping from each individual
DEFVAL { "" } certificate fingerprint to a securityName is possible but
::= { dtlstmCertificateToSNEntry 5 } requires one entry in the table per securityName."
::= { dtlstmCertificateMapping 3 }
dtlstmCertStorageType OBJECT-TYPE dtlstmCertificateToSNEntry OBJECT-TYPE
SYNTAX StorageType SYNTAX DtlstmCertificateToSNEntry
MAX-ACCESS read-create MAX-ACCESS not-accessible
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The storage type for this conceptual row. Conceptual rows "A row in the dtlstmCertificateToSNTable that specifies a
having the value 'permanent' need not allow write-access to mapping for an incoming DTLS certificate to a securityName to
any columnar objects in the row." use for the connection."
DEFVAL { nonVolatile } INDEX { dtlstmCertID }
::= { dtlstmCertificateToSNEntry 6 } ::= { dtlstmCertificateToSNTable 1 }
dtlstmCertRowStatus OBJECT-TYPE DtlstmCertificateToSNEntry ::= SEQUENCE {
SYNTAX RowStatus dtlstmCertID Unsigned32,
MAX-ACCESS read-create dtlstmCertHashType X509IdentifierHashType,
STATUS current dtlstmCertHashValue X509IdentifierHash,
DESCRIPTION dtlstmCertMapType INTEGER,
"The status of this conceptual row. This object may be used dtlstmCertSecurityName SnmpAdminString,
to create or remove rows from this table. dtlstmCertStorageType StorageType,
dtlstmCertRowStatus RowStatus
}
The value of this object has no effect on whether dtlstmCertID OBJECT-TYPE
other objects in this conceptual row can be modified." SYNTAX Unsigned32
::= { dtlstmCertificateToSNEntry 7 } MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique arbitrary number index for a given certificate
entry."
::= { dtlstmCertificateToSNEntry 1 }
dtlstmCertHashType OBJECT-TYPE
SYNTAX X509IdentifierHashType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The hash algorithm to use when applying a hash to a X.509
certificate for purposes of referring to it from the
dtlstmCertHashValue column.
dtlstmParamsCount OBJECT-TYPE The md5(1) value SHOULD NOT be used."
SYNTAX Unsigned32 DEFVAL { sha256 }
MAX-ACCESS read-only ::= { dtlstmCertificateToSNEntry 2 }
STATUS current
DESCRIPTION
"A count of the number of entries in the
dtlstmParamsTable"
::= { dtlstmCertificateMapping 4 }
dtlstmParamsTableLastChanged OBJECT-TYPE dtlstmCertHashValue OBJECT-TYPE
SYNTAX TimeStamp SYNTAX X509IdentifierHash
MAX-ACCESS read-only MAX-ACCESS read-create
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The value of sysUpTime.0 when the dtlstmParamsTable "A cryptographic hash of a X.509 certificate. The use of this
was last modified through any means, or 0 if it has not been hash is dictated by the dtlstmCertMapType column.
modified since the command responder was started." "
::= { dtlstmCertificateMapping 5 } ::= { dtlstmCertificateToSNEntry 3 }
dtlstmParamsTable OBJECT-TYPE dtlstmCertMapType OBJECT-TYPE
SYNTAX SEQUENCE OF DtlstmParamsEntry SYNTAX INTEGER { specified(1), bySubjectAltName(2), byCN(3) }
MAX-ACCESS not-accessible MAX-ACCESS read-create
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"This table augments the SNMP-TARGET-MIB's "The mapping type used to obtain the securityName from the
snmpTargetParamsTable with additional a DTLS client-side certificate. The possible values of use and their usage
certificate certificate identifier to use when establishing methods are defined as follows:
new DTLS connections."
::= { dtlstmCertificateMapping 6 }
dtlstmParamsEntry OBJECT-TYPE specified(1): The securityName that should be used locally to
SYNTAX DtlstmParamsEntry identify the remote entity is directly specified
MAX-ACCESS not-accessible in the dtlstmCertSecurityName column from this
STATUS current table. The dtlstmCertHashValue MUST refer to a
DESCRIPTION X.509 client certificate that will be mapped
"A conceptual row containing a locally held certificate's hash directly to the securityName specified in the
type and hash value for a given snmpTargetParamsEntry. The dtlstmCertSecurityName column.
values in this row should be ignored if not the connection
that needs to be established, as indicated by the
SNMP-TARGET-MIB infrastructure, is not a DTLS based
connection."
AUGMENTS { snmpTargetParamsEntry }
::= { dtlstmParamsTable 1 }
DtlstmParamsEntry ::= SEQUENCE { bySubjectAltName(2):
dtlstmParamsHashType X509IdentifierHashType, The securityName that should be used locally to
dtlstmParamsHashValue X509IdentifierHash, identify the remote entity should be taken from
dtlstmParamsStorageType StorageType, the subjectAltName portion of the X.509
dtlstmParamsRowStatus RowStatus certificate. The dtlstmCertHashValue MUST refer
} to a trust anchor certificate that is
responsible for issuing certificates with
carefully controlled subjectAltName fields.
dtlstmParamsHashType OBJECT-TYPE byCN(3): The securityName that should be used locally to
SYNTAX X509IdentifierHashType identify the remote entity should be taken from
MAX-ACCESS read-create the CommonName portion of the Subject field from
STATUS current the X.509 certificate. The dtlstmCertHashValue
DESCRIPTION MUST refer to a trust anchor certificate that is
"The hash algorithm type for the hash stored in the responsible for issuing certificates with
dtlstmParamsHash column to identify a locally-held X.509 carefully controlled CommonName fields."
certificate that should be used when initiating a DTLS DEFVAL { specified }
connection as a DTLS client." ::= { dtlstmCertificateToSNEntry 4 }
DEFVAL { sha256 }
::= { dtlstmParamsEntry 1 }
dtlstmParamsHashValue OBJECT-TYPE dtlstmCertSecurityName OBJECT-TYPE
SYNTAX X509IdentifierHash SYNTAX SnmpAdminString (SIZE(0..32))
MAX-ACCESS read-create MAX-ACCESS read-create
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"A cryptographic hash of a X.509 certificate. This object "The securityName that the session should use if the
should store the hash of a locally held X.509 certificate that dtlstmCertMapType is set to specified(1), otherwise the value
should be used when initiating a DTLS connection as a DTLS in this column should be ignored. If dtlstmCertMapType is set
client." to specifed(1) and this column contains a zero-length string
::= { dtlstmParamsEntry 2 } (which is not a legal securityName value) this row is
effectively disabled and the match will not be considered
successful."
DEFVAL { "" }
::= { dtlstmCertificateToSNEntry 5 }
dtlstmParamsStorageType OBJECT-TYPE dtlstmCertStorageType OBJECT-TYPE
SYNTAX StorageType SYNTAX StorageType
MAX-ACCESS read-create MAX-ACCESS read-create
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The storage type for this conceptual row. Conceptual rows "The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to having the value 'permanent' need not allow write-access to
any columnar objects in the row." any columnar objects in the row."
DEFVAL { nonVolatile } DEFVAL { nonVolatile }
::= { dtlstmParamsEntry 3 } ::= { dtlstmCertificateToSNEntry 6 }
dtlstmParamsRowStatus OBJECT-TYPE dtlstmCertRowStatus OBJECT-TYPE
SYNTAX RowStatus SYNTAX RowStatus
MAX-ACCESS read-create MAX-ACCESS read-create
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"The status of this conceptual row. This object may be used "The status of this conceptual row. This object may be used
to create or remove rows from this table. to create or remove rows from this table.
The value of this object has no effect on whether The value of this object has no effect on whether
other objects in this conceptual row can be modified." other objects in this conceptual row can be modified."
::= { dtlstmParamsEntry 4 } ::= { dtlstmCertificateToSNEntry 7 }
-- Maps securityNames to certificates for use by the SNMP-TARGET-MIB
dtlstmCompliances OBJECT IDENTIFIER ::= { dtlstmConformance 1 } dtlstmParamsCount OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A count of the number of entries in the
dtlstmParamsTable"
::= { dtlstmCertificateMapping 4 }
dtlstmGroups OBJECT IDENTIFIER ::= { dtlstmConformance 2 } dtlstmParamsTableLastChanged OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime.0 when the dtlstmParamsTable
was last modified through any means, or 0 if it has not been
modified since the command responder was started."
::= { dtlstmCertificateMapping 5 }
dtlstmParamsTable OBJECT-TYPE
SYNTAX SEQUENCE OF DtlstmParamsEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table augments the SNMP-TARGET-MIB's
snmpTargetParamsTable with additional a DTLS client-side
certificate certificate identifier to use when establishing
new DTLS connections."
::= { dtlstmCertificateMapping 6 }
dtlstmCompliance MODULE-COMPLIANCE dtlstmParamsEntry OBJECT-TYPE
STATUS current SYNTAX DtlstmParamsEntry
DESCRIPTION MAX-ACCESS not-accessible
"The compliance statement for SNMP engines that support the STATUS current
SNMP-DTLS-TM-MIB" DESCRIPTION
MODULE "A conceptual row containing a locally held certificate's hash
MANDATORY-GROUPS { dtlstmStatsGroup, type and hash value for a given snmpTargetParamsEntry. The
dtlstmIncomingGroup, dtlstmOutgoingGroup } values in this row should be ignored if not the connection
::= { dtlstmCompliances 1 } that needs to be established, as indicated by the
SNMP-TARGET-MIB infrastructure, is not a DTLS based
connection."
AUGMENTS { snmpTargetParamsEntry }
::= { dtlstmParamsTable 1 }
dtlstmStatsGroup OBJECT-GROUP DtlstmParamsEntry ::= SEQUENCE {
OBJECTS { dtlstmParamsHashType X509IdentifierHashType,
dtlstmSessionOpens, dtlstmParamsHashValue X509IdentifierHash,
dtlstmSessionCloses, dtlstmParamsStorageType StorageType,
dtlstmSessionOpenErrors, dtlstmParamsRowStatus RowStatus
dtlstmSessionNoAvailableSessions, }
dtlstmSessionInvalidClientCertificates,
dtlstmSessionInvalidServerCertificates,
dtlstmDTLSProtectionErrors
}
STATUS current
DESCRIPTION
"A collection of objects for maintaining
statistical information of an SNMP engine which
implements the SNMP DTLS Transport Model."
::= { dtlstmGroups 1 }
dtlstmIncomingGroup OBJECT-GROUP dtlstmParamsHashType OBJECT-TYPE
OBJECTS { SYNTAX X509IdentifierHashType
dtlstmCertificateToSNCount, MAX-ACCESS read-create
dtlstmCertificateToSNTableLastChanged, STATUS current
dtlstmCertHashType, DESCRIPTION
dtlstmCertHashValue, "The hash algorithm type for the hash stored in the
dtlstmCertMapType, dtlstmParamsHash column to identify a locally-held X.509
dtlstmCertSecurityName, certificate that should be used when initiating a DTLS
dtlstmCertStorageType, connection as a DTLS client."
dtlstmCertRowStatus DEFVAL { sha256 }
} ::= { dtlstmParamsEntry 1 }
STATUS current
DESCRIPTION
"A collection of objects for maintaining
incoming connection certificate mappings to
securityNames of an SNMP engine which implements the
SNMP DTLS Transport Model."
::= { dtlstmGroups 2 }
dtlstmOutgoingGroup OBJECT-GROUP dtlstmParamsHashValue OBJECT-TYPE
OBJECTS { SYNTAX X509IdentifierHash
dtlstmParamsCount, MAX-ACCESS read-create
dtlstmParamsTableLastChanged, STATUS current
dtlstmParamsHashType, DESCRIPTION
dtlstmParamsHashValue, "A cryptographic hash of a X.509 certificate. This object
dtlstmParamsStorageType, should store the hash of a locally held X.509 certificate that
dtlstmParamsRowStatus should be used when initiating a DTLS connection as a DTLS
} client."
STATUS current
DESCRIPTION
"A collection of objects for maintaining
outgoing connection certificates to use when opening
connections as a result of SNMP-TARGET-MIB settings."
::= { dtlstmGroups 3 }
END ::= { dtlstmParamsEntry 2 }
dtlstmParamsStorageType 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 }
::= { dtlstmParamsEntry 3 }
dtlstmParamsRowStatus 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.
The value of this object has no effect on whether
other objects in this conceptual row can be modified."
::= { dtlstmParamsEntry 4 }
-- ************************************************
-- dtlstmMIB - Conformance Information
-- ************************************************
dtlstmCompliances OBJECT IDENTIFIER ::= { dtlstmConformance 1 }
dtlstmGroups OBJECT IDENTIFIER ::= { dtlstmConformance 2 }
-- ************************************************
-- Compliance statements
-- ************************************************
dtlstmCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for SNMP engines that support the
SNMP-DTLS-TM-MIB"
MODULE
MANDATORY-GROUPS { dtlstmStatsGroup,
dtlstmIncomingGroup, dtlstmOutgoingGroup }
::= { dtlstmCompliances 1 }
-- ************************************************
-- Units of conformance
-- ************************************************
dtlstmStatsGroup OBJECT-GROUP
OBJECTS {
dtlstmSessionOpens,
dtlstmSessionCloses,
dtlstmSessionOpenErrors,
dtlstmSessionNoAvailableSessions,
dtlstmSessionInvalidClientCertificates,
dtlstmSessionInvalidServerCertificates,
dtlstmDTLSProtectionErrors
}
STATUS current
DESCRIPTION
"A collection of objects for maintaining
statistical information of an SNMP engine which
implements the SNMP DTLS Transport Model."
::= { dtlstmGroups 1 }
dtlstmIncomingGroup OBJECT-GROUP
OBJECTS {
dtlstmCertificateToSNCount,
dtlstmCertificateToSNTableLastChanged,
dtlstmCertHashType,
dtlstmCertHashValue,
dtlstmCertMapType,
dtlstmCertSecurityName,
dtlstmCertStorageType,
dtlstmCertRowStatus
}
STATUS current
DESCRIPTION
"A collection of objects for maintaining
incoming connection certificate mappings to
securityNames of an SNMP engine which implements the
SNMP DTLS Transport Model."
::= { dtlstmGroups 2 }
dtlstmOutgoingGroup OBJECT-GROUP
OBJECTS {
dtlstmParamsCount,
dtlstmParamsTableLastChanged,
dtlstmParamsHashType,
dtlstmParamsHashValue,
dtlstmParamsStorageType,
dtlstmParamsRowStatus
}
STATUS current
DESCRIPTION
"A collection of objects for maintaining
outgoing connection certificates to use when opening
connections as a result of SNMP-TARGET-MIB settings."
::= { dtlstmGroups 3 }
END
8. Operational Considerations 8. Operational Considerations
This section discusses various operational aspects of the solution This section discusses various operational aspects of the solution
8.1. Sessions 8.1. Sessions
A session is discussed throughout this document as meaning a security A session is discussed throughout this document as meaning a security
association between the DTLS client and the DTLS server. State association between the DTLS client and the DTLS server. State
information for the sessions are maintained in each DTLSTM and this information for the sessions are maintained in each DTLSTM and this
skipping to change at page 51, line 6 skipping to change at page 49, line 43
contextEngineID discovery mechanism. A recommended discovery contextEngineID discovery mechanism. A recommended discovery
solution is documented in [RFC5343]. solution is documented in [RFC5343].
9. Security Considerations 9. Security Considerations
This document describes a transport model that permits SNMP to This document describes a transport model that permits SNMP to
utilize DTLS security services. The security threats and how the utilize DTLS security services. The security threats and how the
DTLS transport model mitigates these threats are covered in detail DTLS transport model mitigates these threats are covered in detail
throughout this document. Security considerations for DTLS are throughout this document. Security considerations for DTLS are
covered in [RFC4347] and security considerations for TLS are covered in [RFC4347] and security considerations for TLS are
described in Appendices D, E, and F of TLS 1.1 [RFC4346]. DTLS adds described in Section 11 and Appendices D, E, and F of TLS 1.2
to the security considerations of TLS only because it is more [RFC5246]. DTLS adds to the security considerations of TLS only
vulnerable to denial of service attacks. A random cookie exchange because it is more vulnerable to denial of service attacks. A random
was added to the handshake to prevent anonymous denial of service cookie exchange was added to the handshake to prevent anonymous
attacks. RFC 4347 recommends that the cookie exchange is utilized denial of service attacks. RFC 4347 recommends that the cookie
for all handshakes and therefore it is RECOMMENDED that implementers exchange is utilized for all handshakes and therefore it is
also support this cookie exchange. RECOMMENDED that implementers also support this cookie exchange.
9.1. Certificates, Authentication, and Authorization 9.1. Certificates, Authentication, and Authorization
Implementations are responsible for providing a security certificate Implementations are responsible for providing a security certificate
configuration installation . Implementations SHOULD support configuration installation . Implementations SHOULD support
certificate revocation lists and expiration of certificates or other certificate revocation lists and expiration of certificates or other
access control mechanisms. access control mechanisms.
DTLS provides for both authentication of the identity of the DTLS DTLS provides for both authentication of the identity of the DTLS
server and authentication of the identity of the DTLS client. Access server and authentication of the identity of the DTLS client. Access
to MIB objects for the authenticated principal MUST be enforced by an to MIB objects for the authenticated principal MUST be enforced by an
access control subsystem (e.g. the VACM). access control subsystem (e.g. the VACM).
Authentication of the Command Generator principal's identity is Authentication of the Command Generator principal's identity is
important for use with the SNMP access control subsystem to ensure important for use with the SNMP access control subsystem to ensure
that only authorized principals have access to potentially sensitive that only authorized principals have access to potentially sensitive
data. The authenticated identity of the Command Generator data. The authenticated identity of the Command Generator
principal's certificate is mapped to an SNMP model-independent principal's certificate is mapped to an SNMP model-independent
securityName for use with SNMP access control, as discussed in securityName for use with SNMP access control.
Section 4.5.3.4, Section 7 and other sections.
Furthermore, the DTLS handshake only provides assurance that the Furthermore, the DTLS handshake only provides assurance that the
certificate of the authenticated identity has been signed by an certificate of the authenticated identity has been signed by an
configured accepted Certificate Authority. DTLS has no way to configured accepted Certificate Authority. DTLS has no way to
further authorize or reject access based on the authenticated further authorize or reject access based on the authenticated
identity. An Access Control Model (such as the VACM) provides access identity. An Access Control Model (such as the VACM) provides access
control and authorization of a Command Generator's requests to a control and authorization of a Command Generator's requests to a
Command Responder and a Notification Responder's authorization to Command Responder and a Notification Responder's authorization to
receive Notifications from a Notification Originator. However to receive Notifications from a Notification Originator. However to
avoid man-in-the-middle attacks both ends of the DTLS based avoid man-in-the-middle attacks both ends of the DTLS based
skipping to change at page 53, line 7 skipping to change at page 51, line 43
including full support for the USM (see [RFC3414]) and the DTLS including full support for the USM (see [RFC3414]) and the DTLS
Transport Model cryptographic mechanisms (for authentication and Transport Model cryptographic mechanisms (for authentication and
privacy). privacy).
10. IANA Considerations 10. IANA Considerations
IANA is requested to assign: IANA is requested to assign:
1. a UDP port number in the range 1..1023 in the 1. a UDP port number in the range 1..1023 in the
http://www.iana.org/assignments/port-numbers registry which will http://www.iana.org/assignments/port-numbers registry which will
be the default port for SNMP over a DTLS Transport Model as be the default port for SNMP command messages over a DTLS/UDP
defined in this document, Transport Model as defined in this document,
2. a UDP port number in the range 1..1023 in the 2. a UDP port number in the range 1..1023 in the
http://www.iana.org/assignments/port-numbers registry which will http://www.iana.org/assignments/port-numbers registry which will
be the default port for SNMPTRAP over a DTLS Transport Model as be the default port for SNMP notification messages over a DTLS/
defined in this document, UDP Transport Model as defined in this document,
3. an SMI number under snmpDomains for the snmpDTLSDomain object 3. a SCTP port number in the range 1..1023 in the
http://www.iana.org/assignments/port-numbers registry which will
be the default port for SNMP command messages over a DTLS/SCTP
Transport Model as defined in this document,
4. a SCTP port number in the range 1..1023 in the
http://www.iana.org/assignments/port-numbers registry which will
be the default port for SNMP notification messages over a DTLS/
SCTP Transport Model as defined in this document,
5. an SMI number under snmpDomains for the snmpDTLSUDPDomain object
identifier, identifier,
4. a SMI number under snmpModules, for the MIB module in this 6. an SMI number under snmpDomains for the snmpDTLSSCTPDomain object
identifier,
7. a SMI number under snmpModules, for the MIB module in this
document, document,
5. "dtls" as the corresponding prefix for the snmpDTLSDomain in the 8. "dudp" as the corresponding prefix for the snmpDTLSUDPDomain in
SNMP Transport Model registry; the SNMP Transport Model registry,
9. "dsct" as the corresponding prefix for the snmpDTLSSCTPDomain in
the SNMP Transport Model registry;
11. Acknowledgements 11. Acknowledgements
This document closely follows and copies the Secure Shell Transport This document closely follows and copies the Secure Shell Transport
Model for SNMP defined by David Harrington and Joseph Salowey in Model for SNMP defined by David Harrington and Joseph Salowey in
[I-D.ietf-isms-secshell]. [I-D.ietf-isms-secshell].
This work was supported in part by the United States Department of This work was supported in part by the United States Department of
Defense. Large portions of this document are based on work by Defense. Large portions of this document are based on work by
General Dynamics C4 Systems and the following individuals: Brian General Dynamics C4 Systems and the following individuals: Brian
skipping to change at page 54, line 44 skipping to change at page 53, line 49
[RFC3418] Presuhn, R., "Management Information Base (MIB) for the [RFC3418] Presuhn, R., "Management Information Base (MIB) for the
Simple Network Management Protocol (SNMP)", STD 62, Simple Network Management Protocol (SNMP)", STD 62,
RFC 3418, December 2002. RFC 3418, December 2002.
[RFC3584] Frye, R., Levi, D., Routhier, S., and B. Wijnen, [RFC3584] Frye, R., Levi, D., Routhier, S., and B. Wijnen,
"Coexistence between Version 1, Version 2, and Version 3 "Coexistence between Version 1, Version 2, and Version 3
of the Internet-standard Network Management Framework", of the Internet-standard Network Management Framework",
BCP 74, RFC 3584, August 2003. BCP 74, RFC 3584, August 2003.
[RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.1", RFC 4346, April 2006.
[RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer [RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security", RFC 4347, April 2006. Security", RFC 4347, April 2006.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008. (CRL) Profile", RFC 5280, May 2008.
[I-D.ietf-isms-transport-security-model] [I-D.ietf-isms-transport-security-model]
Harington, D., "Transport Security Model for SNMP". Harington, D., "Transport Security Model for SNMP".
[I-D.ietf-isms-tmsm] [I-D.ietf-isms-tmsm]
Harington, D. and J. Schoenwaelder, "Transport Subsystem Harington, D. and J. Schoenwaelder, "Transport Subsystem
skipping to change at page 59, line 4 skipping to change at line 2606
Author's Address Author's Address
Wes Hardaker Wes Hardaker
Sparta, Inc. Sparta, Inc.
P.O. Box 382 P.O. Box 382
Davis, CA 95617 Davis, CA 95617
US US
Phone: +1 530 792 1913 Phone: +1 530 792 1913
Email: ietf@hardakers.net Email: ietf@hardakers.net
Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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this document or the extent to which any license under such rights
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made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
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Copies of IPR disclosures made to the IETF Secretariat and any
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The IETF invites any interested party to bring to its attention any
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