One document matched: draft-ietf-radext-management-authorization-02.txt
Differences from draft-ietf-radext-management-authorization-01.txt
Network Working Group D. Nelson
Internet-Draft Elbrys Networks, Inc.
Intended status: Standards Track G. Weber
Expires: August 27, 2008 February 24, 2008
Remote Authentication Dial-In User Service (RADIUS) Authorization for
Network Access Server (NAS) Management
draft-ietf-radext-management-authorization-02.txt
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Copyright Notice
Copyright (C) The IETF Trust (2008).
Abstract
This document describes Remote Authentication Dial-In User Service
(RADIUS) attributes for the authorization and service provisioning of
local and remote management of embedded systems and other managed
entities, generally referred to as Network Access Servers (NASes).
Specific provisions are made for remote management via framed
management protocols, for granular levels of access rights and
management privileges, and for specification of a protected transport
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protocol.
Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction and Rationale . . . . . . . . . . . . . . . . . . 3
3. Provisions for Framed Management . . . . . . . . . . . . . . . 3
4. Provisions for Granular Management Access Rights . . . . . . . 4
5. Provisions for Secure Management Access . . . . . . . . . . . 4
6. Current Practice for CLI Management Access . . . . . . . . . . 4
7. New Values for Existing RADIUS Attributes . . . . . . . . . . 5
7.1. Service-Type . . . . . . . . . . . . . . . . . . . . . . . 5
8. New RADIUS Attributes . . . . . . . . . . . . . . . . . . . . 6
8.1. Framed-Management-Protocol . . . . . . . . . . . . . . . . 6
8.2. Management-Transport-Protection . . . . . . . . . . . . . 8
8.3. Management-Policy-Id . . . . . . . . . . . . . . . . . . . 10
8.4. Management-Privilege-Level . . . . . . . . . . . . . . . . 11
9. Examples of attribute groupings . . . . . . . . . . . . . . . 12
10. Diameter Translation Considerations . . . . . . . . . . . . . 14
11. RADIUS Proxy Operation Considerations . . . . . . . . . . . . 15
12. Table of Attributes . . . . . . . . . . . . . . . . . . . . . 16
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
14. Security Considerations . . . . . . . . . . . . . . . . . . . 16
15. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17
16. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
16.1. Normative References . . . . . . . . . . . . . . . . . . . 18
16.2. Informative References . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
Intellectual Property and Copyright Statements . . . . . . . . . . 20
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1. Terminology
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 RFC 2119 [RFC2119].
This document uses terminology from RFC 2865 [RFC2865] and RFC 2866
[RFC2866].
2. Introduction and Rationale
The remote management Service-Types defined in RFC 2865 [RFC2865]
include NAS-Prompt and Administrative. Both of these services
provide access to the interactive, text-based, Command Line Interface
(CLI) of the managed entity. Current deployments of network
equipment include in the managed entity non-CLI, framed-protocol
forms of management, such as web browser based management, SNMP, and
NETCONF. In addition, network devices often support more privilege
levels for management access than the two levels supported by NAS-
Prompt (non-privileged) and Administrative (privileged). To address
these issues, attributes for framed management protocols, management
protocol security levels, and management access privilege levels are
described.
3. Provisions for Framed Management
Framed Management means management of an entity by means of a non-
interactive, non-CLI-style method. The management information is
typically formatted in a binary or textual encoding, such as HTML,
XML or ASN.1/BER. While remote management by interactive CLI
sessions is carried over protocols, such as Telnet, Rlogin, and SSH,
these protocols are primarily for the delivery of terminal, or
pseudo-TTY services. Note that, in this context, "SSH" means the
remote terminal service of SSH, not the more general protected
transport service of SSH. Command Line Interface, Menu Interface, or
other text-based (e.g. ASCII or UTF-8) terminal emulation interfaces
are not considered to be Framed Management protocols, as used in this
document. Examples of Framed Management protocols include web-based
management (HTML over HTTP or HTTPS), NETCONF (XML over HTTP/BEEP/
SOAP) and SNMP (SMI over ASN.1/BER).
To support the authorization and provisioning of Framed Management
access to managed entities, this document introduces a new value for
the Service-Type attribute [RFC2865], and one new attribute. The new
value for the Service-Type attribute is Framed-Management. The
definition of this service is the provisioning of remote device
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management via a Framed Management protocol, as described in this
section. The new attribute is Framed-Management-Protocol, the value
of which specifies a particular protocol for use in the remote
management session.
4. Provisions for Granular Management Access Rights
Two new attributes are introduced in this document in support of
granular management access rights or command privilege levels.
The Management-Policy-Id attribute is used to contain the name of a
management access rights policy of local scope. This attribute
functions similarly to Filter-ID. It is a string variable containing
a policy name of local scope. The provisioning of the rules invoked
by application of this management policy is by means outside the
scope of this document, such as by MIB objects.
The local application of the Management-Policy-Id within the managed
entity may take the form of (a) one of an enumeration of command
privilege levels, (b) a mapping into an SNMP Access Control Model,
such as the View Based Access Control Model (VACM) table [RFC3415],
or (c) some other set of management access policy rules that is
mutually understood by the managed entity and the remote management
application. Examples are given in Section 9.
The Management-Privilege-Level attribute is used to contain an
Integer-valued management privilege level indication. This attribute
serves to modify or augment the management permissions bestowed by
the NAS-Prompt Service-Type, and thus applies to CLI management
interfaces.
5. Provisions for Secure Management Access
To provide for the provisioning of secure management methods, via
various secure transport protocols, one new attribute is introduced
in this document, Management-Transport-Protection. The value of this
attribute indicates the level of secure transport protocol protection
that is required for the provisioning of NAS-Prompt, Administrative
or Framed-Management service.
6. Current Practice for CLI Management Access
To aid in understanding of this document, it is helpful to review
current RADIUS implementation practice with regard to the
provisioning of management access to the Command Line Interface (CLI)
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of the NAS. The RADIUS Service-Type values of NAS-Prompt and
Administrative originally applied to access via a physical console
port of the NAS, most often a serial port. Remote access to the CLI
of the NAS over remote terminal protocols such as Telnet, Rlogin and
SSH, has been available in many NAS implementations for many years.
In order to distinguish local, physical console, access from remote
access, the NAS-Port-Type attribute is generally included in Access-
Request and Access-Accept messages, along with the Service-Type, to
indicate the form of access. A NAS-Port-Type of Async (0) is used to
signify a local serial port connection, while a value of Virtual (5)
is used to signify a remote connection, via a remote terminal
protocol. This usage provides no selectivity among the various
available remote terminal protocols (e.g. Telnet, Rlogin, SSH,
etc.).
It is expected that the additional features of this document with
respect to remote access to the CLI of a NAS will be used in
conjunction with the existing practice regarding the NAS-Port-Type
attribute described in this section.
7. New Values for Existing RADIUS Attributes
7.1. Service-Type
This document defines one new value for an existing RADIUS attribute.
The Service-Type attribute is defined in Section 5.6 of RFC 2865
[RFC2865], as follows:
This Attribute indicates the type of service the user has requested,
or the type of service to be provided. It MAY be used in both
Access-Request and Access-Accept packets.
A NAS is not required to implement all of these service types, and
MUST treat unknown or unsupported Service-Types as though an Access-
Reject had been received instead.
A summary of the Service-Type Attribute format is shown below.
The fields are transmitted from left to right.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
6 for Service-Type.
Length
6 Value
The Value field is four octets.
This document defines one new value for the Service-Type
attribute.
(TBA) Framed-Management
The semantics of the Framed-Management service are as follows:
Framed-Management A framed management protocol session should
be started on the NAS.
8. New RADIUS Attributes
This document defines four new RADIUS attributes related to remote
management authorization.
8.1. Framed-Management-Protocol
The Framed-Management-Protocol attribute indicates the application-
layer management protocol to be used for framed management access.
It MAY be used in both Access-Request and Access-Accept packets.
This attribute is used in conjunction with a Service-Type of Framed-
Management.
A summary of the Framed-Management-Protocol attribute format is shown
below. The fields are transmitted from left to right.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
(TBA) for Framed-Management-Protocol.
Length
6
Value
The Value field is four octets.
1 SNMP
2 Web-based
3 NETCONF
4 FTP
5 TFTP
6 CP
The acronyms used in the above table expand as follows:
o SNMP: Simple Network Management Protocol.
o Web-based: Use of an embedded web server in the NAS for management
via a generic web browser client. The interface presented to the
administrator may be graphical, tabular or textual. The protocol
is HTML over HTTP. The protocol may optionally be HTML over
HTTPS, i.e. using HTTP over TLS.
o NETCONF: Management via the NETCONF protocol using XML over
supported transports (e.g. HTTP, BEEP, SOAP). As secure
transport profiles are defined for NETCONF, the list of transport
options may expand.
o FTP: File Transfer Protocol, used to transfer configuration files
to and from the NAS.
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o TFTP: Trivial File Transfer Protocol, used to transfer
configuration files to and from the NAS.
o CP: CP (file copy) protocol, used to transfer configuration files
to and from the NAS.
8.2. Management-Transport-Protection
The Management-Transport-Protection attribute specifies whether a
secure transport protocol (e.g. SSH, TLS, DTLS, etc.) is required
for use with the associated framed or non-framed management access
session. The value of this attribute specifies the minimum level of
protection that is required from the protected transport. The
protected transport MAY provide a greater level of protection than is
called for by the value of Management-Transport-Protection.
When a secure form of non-framed management access is specified, it
means that the remote terminal session is encapsulated in some form
of protected transport, or tunnel. It may also mean that an explicit
secure mode of operation is required, when the framed management
protocol contains an intrinsic secure mode of operation. The
Management-Transport-Protocol attribute does not apply to CLI access
via a local serial port, or other non-remote connection.
When a secure form of framed management access is specified, it means
that the application-layer management protocol is encapsulated in
some form of protected transport, or tunnel. It may also mean that
an explicit secure mode of operation is required, when the framed
management protocol contains an intrinsic secure mode of operation.
A value of "No Protection (1)" indicates that a secure transport
protocol is not required, and that the NAS SHOULD accept a connection
over any transport associated with the application layer management
protocol. Note that the definitions of management application to
transport bindings are defined in the relevant documents that specify
those management application protocols. The same "No Protection"
semantics are conveyed by omitting this attribute from an Access-
Accept packet.
Note that specific protected transport protocols, cipher suites, key
agreement methods, or authentication methods are not specified by
this attribute. Such provisioning is beyond the scope of this
document.
A summary of the Management-Transport-Protection Attribute format is
shown below. The fields are transmitted from left to right.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
(TBA) for Management-Transport-Protection.
Length
6
Value
The Value field is four octets.
1 No-Protection
2 Integrity-Protection
3 Confidentiality-Protection
4 Integrity-Confidentiality-Protection
The acronyms used in the above table expand as follows:
o No-Protection: No transport protection is required. Accept
connections via any supported transport.
o Integrity-Protection: The management session requires protection
in a secure or protected transport, that is supported by the
management access protocol and implementation. The secure
transport MUST provide Integrity Protection.
o Confidentiality-Protection: The management session requires
protection in a secure or protected transport, that is supported
by the management access protocol and implementation. The secure
transport MUST provide Confidentiality Protection.
o Integrity-Confidentiality-Protection: The management session
requires protection in a secure or protected transport, that is
supported by the management access protocol and implementation.
The secure transport MUST provide both Integrity Protection and
Confidentiality Protection.
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8.3. Management-Policy-Id
The Management-Policy-Id attribute indicates the name of the
management access policy for this user. Zero or more Management-
Policy-Id attributes MAY be sent in an Access-Accept packet.
Identifying a policy by name allows the policy to be used on
different NASes without regard to implementation details.
Multiple forms of management access rules may be expressed by the
underlying named policy, the definition of which is beyond the scope
of this document. The management access policy MAY be applied
contextually, based on the nature of the management access method.
For example, some named policies may only be valid for application to
NAS-Prompt services and some other policies may only be valid for
application to SMNPv3 services.
The management access policy named in this attribute, received in an
Access-Accept packet, MUST be applied to the session authorized by
the Access-Accept. If the NAS supports this attribute, but the
policy name is unknown, or the policy rules are incorrectly
formatted, the NAS MUST treat the packet as if it had been an Access-
Reject.
No precedence relationship is defined for multiple occurrences of the
Management-Policy-Id attribute. NAS behavior in such cases is not
predictable. Therefore, two or more occurrences of this attribute
SHOULD NOT be included in a single service provisioning message, such
as Access-Accept or CoA.
The content of the Management-Policy-Id attribute is expected to be
the name of a management access policy of local significance to the
NAS, within a flat namespace of significance to the NAS. In this
regard, the behavior is similar to that for the Filter-Id attribute.
The policy names and rules are committed to the local configuration
store of the NAS, and are provisioned by means beyond the scope of
this document, such as via SNMP, NETCONF or CLI.
Overloading or subdividing this flat name with multi-part specifiers
(e.g. Access=remote, Level=7) is likely to lead to poor multi-vendor
interoperability and SHOULD NOT be utilized. If a simple flat policy
name is not sufficient to the anticipated use case, it is RECOMMEDNED
that a Vendor Specific Attribute be used instead, rather than
overloading the semantics of Management-Policy-Id.
A summary of the Management-Policy-Id Attribute format is shown
below. The fields are transmitted from left to right.
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0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Type | Length | Text ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Type
(TBA) for Management-Policy-Id.
Length
>= 3
Text
The Text field is one or more octets, and its contents are
implementation dependent. It is intended to be human readable and
MUST NOT affect operation of the protocol. It is recommended that
the message contain UTF-8 encoded 10646 [RFC3629] characters.
8.4. Management-Privilege-Level
The Management-Privilege-Level attribute indicates the integer
Privilege level to be assigned for management access for the
authenticated user. Many NASes provide the notion of differentiated
management privilege levels denoted by an integer value. The
specific access rights conferred by each value are implementation
dependent. It MAY be used in both Access-Request and Access-Accept
packets.
The management access level indicated in this attribute, received in
an Access-Accept packet, MUST be applied to the session authorized by
the Access-Accept. If the NAS supports this attribute, but the
privilege level is unknown, the NAS MUST treat the packet as if it
had been an Access-Reject.
A summary of the Management-Privilege-Level attribute format is show
below. The fields are transmitted from left to right.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
(TBA) for Management-Privilege-Level.
Length
6
Value
The Value field is an Integer, denoting a management
privilege level.
It is RECOMMENDED to limit use of Management-Privilege-Level to
sessions where Service-Type is NAS-Prompt (not Administrative).
Typically, NASes treat NAS-Prompt as the minimal privilege CLI
service and Administrative as full privilege. Using the Management-
Privilege-Level attribute with a Service-Type attribute with a value
of NAS-Prompt will have the effect of increasing the minimum
privilege level. Conversely, it is NOT RECOMMENDED to use this
attribute with a Service-Type of Administrative, which may require
decreasing the maximum privilege level.
It is NOT RECOMMENDED to use Management-Privilege-Level in
combination with Management-Policy-Id or for management access
methods other than interactive CLI. The behavior resulting from such
an overlay of management access control provisioning is not defined
by this document, and in the absence of further specification is
likely to lead to unexpected behaviors, especially in multi-vendor
environments.
9. Examples of attribute groupings
1. Unprotected CLI access, via local console or remote terminal
access, to the "super-user" access level:
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* Service-Type (6) = Administrative (6)
* Management-Transport-Protection (xx) = No-Protection (1)
2. CLI access, via a fully-protected secure remote terminal service
to the non-privileged user access level:
* Service-Type (6) = NAS-Prompt (7)
* Management-Transport-Protection (xx) = Integrity-
Confidentiality-Protection (4)
3. CLI access, via a confidentiality protected secure remote
terminal service of SSH, to a custom management access level,
defined by a policy:
* Service-Type (6) = NAS-Prompt (7)
* Transport-Protocol (xx) = SSH (2)
* Management-Transport-Protection (xx) = Confidentiality-
Protection (3)
* Management-Policy-Id (xx) = "Network Administrator"
4. CLI access, via a fully-protected secure remote terminal service
of SSH, with a management privilege level of 15:
* Service-Type (6) = NAS-Prompt (7)
* Management-Transport-Protection (xx) = SSH (2)
* Management-Transport-Protection (xx) = Integrity-
Confidentiality-Protection (4)
* Management-Privilege-Level (xx) = 15
5. SNMPv3 access, using an Access Control Model specifier, such as a
custom VACM View, defined by a policy:
* Service-Type (6) = Framed-Management (xx)
* Framed-Management-Protocol (xx) = SNMP (1)
* Management-Policy-Id (xx) = "SNMP Network Administrator View"
Note that there is currently no standardized way of implementing
this management policy mapping within SNMPv3. Such mechanisms
are implementation specific.
6. SNMP secure Transport Model access, using the Secure Shell
Transport Model:
* Service-Type (6) = Framed-Management (xx)
* Framed-Management-Protocol (xx) = SNMP (1)
* Transport-Protocol (xx) = SSH (2)
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* Management-Transport-Protection (xx) = Integrity-
Confidentiality-Protection (4)
7. Web (HTTP) access:
* Service-Type (6) = Framed-Management (xx)
* Framed-Management-Protocol (xx) = Web-based (2)
8. Secure web access, using a custom management access level,
defined by a policy:
* Service-Type (6) = Framed-Management (xx)
* Framed-Management-Protocol (xx) = Web-based (2)
* Management-Transport-Protection (xx) = Confidentiality-
Protection (3)
* Management-Policy-Id (xx) = "Read-only web access"
10. Diameter Translation Considerations
When used in Diameter, the attributes defined in this specification
can be used as Diameter AVPs from the Code space 1-255 (RADIUS
attribute compatibility space). No additional Diameter Code values
are therefore allocated. The data types and flag rules for the
attributes are as follows:
+---------------------+
| AVP Flag rules |
|----+-----+----+-----|----+
| | |SHLD| MUST| |
Attribute Name Value Type |MUST| MAY | NOT| NOT|Encr|
---------------------------------|----+-----+----+-----|----|
Service-Type (new value) | | | | | |
Enumerated | M | P | | V | Y |
Framed-Management-Protocol | | | | | |
Enumerated | M | P | | V | Y |
Management-Transport-Protection | | | | | |
Enumerated | M | P | | V | Y |
Management-Policy-Id | | | | | |
UTF8String | M | P | | V | Y |
Management-Privilege-Level | | | | | |
Integer | M | P | | V | Y |
---------------------------------|----+-----+----+-----|----|
The attributes in this specification have no special translation
requirements for Diameter to RADIUS or RADIUS to Diameter gateways;
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they are copied as is, except for changes relating to headers,
alignment, and padding. See also [RFC3588] Section 4.1 and [RFC4005]
Section 9.
What this specification says about the applicability of the
attributes for RADIUS Access-Request packets applies in Diameter to
AA-Request [RFC4005].
What is said about Access-Accept applies in Diameter to AA-Answer
messages that indicate success.
11. RADIUS Proxy Operation Considerations
The device management access authorization attributes presented in
this document present certain considerations when used in RADIUS
proxy environments. These considerations are not different from
those that exist in RFC 2865 [RFC2865] with respect to the Service-
Type attribute values of Administrative and NAS-Prompt.
Most RADIUS proxy environments are also multi-party environments. In
multi-party proxy environments it is important to distinguish which
entities have the authority to provision management access to the
edge devices, i.e. NASes, and which entities only have authority to
provision network access services of various sorts.
It may be important that operators of the NAS are able to ensure that
access to the CLI, or other management interfaces, of the NAS are
only provisioned to their own employees or contractors. One way for
the NAS to enforce this requirement is to use only local, non-proxy
RADIUS servers for management access requests. Proxy RADIUS servers
could be used for non-management access requests, based on local
policy. This "bifurcation" of RADIUS authentication and
authorization is a simple case of separate administrative realms.
The NAS may be designed so as to maintain separate lists of RADIUS
servers for management AAA use and for non-management AAA use.
An alternate method of enforcing this requirement would be for the
first-hop RADIUS proxy server, operated by the owner of the NAS, to
filter out any RADIUS attributes that provision management access
rights that originate from "up-stream" proxy servers not operated by
the NAS owner. Access-Accept messages that provision such locally
un-authorized management access MAY be treated as if they were an
Access-Reject by the first-hop proxy server.
These issues are not of concern when all the RADIUS servers, local
and proxy, used by the NAS are under the sole administrative control
of the NAS owner.
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12. Table of Attributes
The following table provides a guide to which attributes may be found
in which kinds of packets, and in what quantity.
Access-
Request Accept Reject Challenge # Attribute
---------------------------------------------------------------------
0-1 0-1 0 0 TBA Framed-Management-Protocol
0-1 0-1 0 0 TBA Management-Transport-Protection
0 0-1 0 0 TBA Management-Policy-Id
0 0-1 0 0 TBA Management-Privilege-Level
Accounting-
Request Response # Attribute
---------------------------------------------------------------------
0-1 0 TBA Framed-Management-Protocol
0-1 0 TBA Management-Transport-Protection
0-1 0 TBA Management-Policy-Id
0-1 0 TBA Management-Privilege-Level
The following table defines the meaning of the above table entries.
0 This attribute MUST NOT be present in a packet.
0+ Zero or more instances of this attribute MAY be present in
a packet.
0-1 Zero or one instance of this attribute MAY be present in
a packet.
1 Exactly one instance of this attribute MUST be present in
a packet.
13. IANA Considerations
Note to RFC Editor: Remove this paragraph upon publication as an RFC.
This document contains placeholders ("TBA") for assigned numbers
within the RADIUS Attributes registry, to be assigned by IANA at the
time this document should be published as an RFC.
Assignment of additional enumerated values for RADIUS attributes
defined in this document are to be processed as described in
[RFC3575], subject to the additional minimum requirement that a
published specification is always required.
14. Security Considerations
This specification describes the use of RADIUS and Diameter for
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purposes of authentication, authorization and accounting for
management access to devices within networks. RADIUS threats and
security issues for this application are described in [RFC3579] and
[RFC3580]; security issues encountered in roaming are described in
[RFC2607]. For Diameter, the security issues relating to this
application are described in [RFC4005] and [RFC4072].
This document specifies new attributes that can be included in
existing RADIUS packets, which may be protected as described in
[RFC3579] and [RFC3576]. In Diameter, the attributes are protected
as specified in [RFC3588]. See those documents for a more detailed
description.
The security mechanisms supported in RADIUS and Diameter are focused
on preventing an attacker from spoofing packets or modifying packets
in transit. They do not prevent an authorized RADIUS/Diameter server
or proxy from inserting attributes with malicious intent.
Any of the attributes described in this memo, with the exception of
Service-Type, may not be understood by the NAS which receives it. A
legacy NAS not compliant with this specification may silently discard
these attributes while permitting the user to access the management
interface(s) of the NAS. This can lead to users improperly receiving
unauthorized management access to the NAS, or access with greater
levels of access rights than were intended. RADIUS servers SHOULD
attempt to ascertain whether or not the NAS supports these attributes
before sending them in an Access-Accept.
It is possible that certain NAS implementations may not be able to
determine the protection properties of the underlying transport
protocol as specified by the Management-Transport-Protection
attribute. This may be a limitation of the standard application
programming interface of the underlying transport implementation or
of the integration of the transport into the NAS implementation. In
either event, NASes conforming to this specification, which cannot
determine the protection state of the remote management connection
SHOULD treat an Access-Accept message containing a Management-
Transport-Protocol attribute containing a value other than No-
Protection (1) as if it were an Access-Reject message, unless
specifically overridden by local policy configuration.
15. Acknowledgments
Many thanks to all reviewers, including Barney Wolff, Mauricio
Sanchez, David Harrington, Juergen Schoenwaelder, Bernard Aboba.
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16. References
16.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, June 2000.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
16.2. Informative References
[RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy
Implementation in Roaming", RFC 2607, June 1999.
[RFC2866] Rigney, C., "RADIUS Accounting", RFC 2866, June 2000.
[RFC3415] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
Management Protocol (SNMP)", STD 62, RFC 3415,
December 2002.
[RFC3575] Aboba, B., "IANA Considerations for RADIUS (Remote
Authentication Dial In User Service)", RFC 3575,
July 2003.
[RFC3576] Chiba, M., Dommety, G., Eklund, M., Mitton, D., and B.
Aboba, "Dynamic Authorization Extensions to Remote
Authentication Dial In User Service (RADIUS)", RFC 3576,
July 2003.
[RFC3579] Aboba, B. and P. Calhoun, "RADIUS (Remote Authentication
Dial In User Service) Support For Extensible
Authentication Protocol (EAP)", RFC 3579, September 2003.
[RFC3580] Congdon, P., Aboba, B., Smith, A., Zorn, G., and J. Roese,
"IEEE 802.1X Remote Authentication Dial In User Service
(RADIUS) Usage Guidelines", RFC 3580, September 2003.
[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
Arkko, "Diameter Base Protocol", RFC 3588, September 2003.
[RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton,
"Diameter Network Access Server Application", RFC 4005,
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August 2005.
[RFC4072] Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible
Authentication Protocol (EAP) Application", RFC 4072,
August 2005.
Authors' Addresses
David B. Nelson
Elbrys Networks, Inc.
75 Rochester Avenue, Unit 3
Portsmouth, NH 03801
USA
Email: d.b.nelson@comcast.net
Greg Weber
Email: gdweber@gmail.com
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