Network Working Group K. Narayan
Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track D. Nelson
Expires: January 7, 2011 Elbrys Networks, Inc.
R. Presuhn, Ed.
None
July 6, 2010
Using Authentication, Authorization, and Accounting services to
Dynamically Provision View-based Access Control Model User-to-Group
Mappings
draft-ietf-isms-radius-vacm-08.txt
Abstract
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols. It describes the use of
information provided by Authentication, Authorization, and Accounting
(AAA) services, such as the Remote Authentication Dial-In User
Service (RADIUS), to dynamically update user-to-group mappings in the
View-Based Access Control Model (VACM).
Comments are solicited and should be addressed to the working group's
mailing list at isms@ietf.org.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 7, 2011.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. The Internet-Standard Management Framework . . . . . . . . . . 3
3. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. Using AAA services with SNMP . . . . . . . . . . . . . . . 3
4.2. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
5. Structure of the MIB Module . . . . . . . . . . . . . . . . . 5
5.1. Textual Conventions . . . . . . . . . . . . . . . . . . . 5
5.2. The Table Structure . . . . . . . . . . . . . . . . . . . 5
6. Relationship to Other MIB Modules . . . . . . . . . . . . . . 6
6.1. Relationship to the VACM MIB . . . . . . . . . . . . . . . 6
6.2. MIB modules required for IMPORTS . . . . . . . . . . . . . 6
7. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 6
7.1. Sequencing Requirements . . . . . . . . . . . . . . . . . 6
7.2. Actions Upon Session Establishment Indication . . . . . . 7
7.2.1. Creation of Entries in vacmAaaSecurityToGroupTable . . 7
7.2.2. Creation of Entries in vacmSecurityToGroupTable . . . 8
7.2.3. Update of vacmGroupName . . . . . . . . . . . . . . . 8
7.3. Actions Upon Session Termination Indication . . . . . . . 8
7.3.1. Deletion of Entries from
vacmAaaSecurityToGroupTable . . . . . . . . . . . . . 9
7.3.2. Deletion of Entries from vacmSecurityToGroupTable . . 9
8. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 9
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 16
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
12.1. Normative References . . . . . . . . . . . . . . . . . . . 16
12.2. Informative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
This memo specifies a way to simplify the administration of the
access rights granted to users of network management data. It
functions to dynamically provision selected View-Based Access Control
Model (VACM) [RFC3415] MIB objects, based on information received
from an Authentication, Authorization, and Accounting (AAA) service,
such as RADIUS [RFC2865].
This memo requires no changes to the Abstract Service Interface for
the Access Control Subsystem, and requires no changes to the Elements
of Procedure for VACM. It provides a MIB module that reflects the
information provided by the AAA service, along with elements of
procedure for maintaining that information and performing
corresponding updates to VACM MIB data.
2. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current
Internet-Standard Management Framework, please refer to section 7 of
RFC 3410 [RFC3410].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This memo specifies a MIB
module that is compliant to the SMIv2, which is described in STD 58,
RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
[RFC2580].
3. Conventions
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].
4. Overview
4.1. Using AAA services with SNMP
There are two use cases for AAA support of management access via
SNMP. These are (a) service authorization and (b) access control
authorization. The former is discussed in detail in [RFC5608]. The
latter is the subject of this memo.
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The use case assumption here is that roles within an organization,
which are reflected in VACM as groups and rules, change infrequently,
while the users assigned to those roles change much more frequently.
This memo describes how the user-to-role (group) mapping can be
delegated to the RADIUS server, avoiding the need to re-provision
managed devices as users are added, deleted, or assigned new roles in
an organization.
This memo assumes that the detailed access control policies are pre-
configured in VACM, and does not attempt to address the question of
how the policy associated with a given role is put in place.
The only additional information obtained from the AAA service is the
mapping of the authenticated user's identifier to a specific role (or
"group" in VACM terminology) in the access control policy. Dynamic
user authorization for MIB database access control, as defined
herein, is limited to mapping the authenticated user to a group,
which in turn is mapped to whatever rules are already in place in
VACM.
The SNMP architecture [RFC3411] maintains strong modularity and
separation of concerns, separating user identity (authentication)
from user database access rights (authorization). RADIUS, on the
other hand, allows for no such separation of authorization from
authentication. Consequently, the approach here is to leverage
existing RADIUS usage for identifying a principal, documented in
[RFC5608], along with the RADIUS Management-Policy-Id Attribute
[RFC5607].
The tmSessionID (along with its transport model prefix) [RFC5590] is
a suitable identifier for a AAA-authorized "session". This is
because tmSessionID and tmSecurityName, assigned by a AAA-aware
transport model, identify a specific transport session authorized to
offer SNMP service, for which a principal has been AAA-authenticated.
When a RADIUS-Management-Policy-ID Attribute (or equivalent) is bound
to such a transport session and principal authentication, this
binding provides sufficient information to compute dynamic updates to
VACM. How this information is communicated within an implementation
is implementation-dependent; this memo is only concerned with
externally-observable behaviour.
4.2. Applicability
Though this memo was motivated to support the use of specific
Transport Models, such as the Secure Shell Transport Model [RFC5592],
it MAY be used with other implementation environments satisfying
these requirements:
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o use an AAA service for sign-on service and data access
authorization;
o provide an indication of the start of a session for a particular
authenticated principal, identified using a SecurityName, and
provide the corresponding value of vacmGroupName to be used, based
on information provided by the AAA service in use;
o provide an indication of the end of the need for being able to
make access decisions for a particular authenticated principal, as
at the end of a session, whether due to disconnection, termination
due to timeout, or any other reason.
Likewise, although this memo specifically refers to RADIUS, it MAY be
used with other AAA services satisfying these requirements:
o the service provides information semantically equivalent to the
RADIUS Management-Policy-Id Attribute [RFC5607], which corresponds
to a GroupName;
o the service provides an authenticated principal identifier (e.g.,
the RADIUS User-Name Attribute [RFC2865]) which can be transformed
to an equivalent principal identifier in the form of a
SecurityName.
5. Structure of the MIB Module
5.1. Textual Conventions
This MIB module makes use of the SnmpAdminString and
SnmpSecurityModel textual conventions.
5.2. The Table Structure
This MIB module defines a single table, the
vacmAaaSecurityToGroupTable. This table is indexed by the integer
assigned to each security model, the protocol-independent
SecurityName corresponding to a principal, and the unique identifier
of a session. This index structure was chosen to support use cases
in which a given user could potentially have multiple concurrent
sessions, and to support environments in which multiple security
models might find concurrent usage.
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6. Relationship to Other MIB Modules
This MIB module has a close operational relationship with the SNMP-
VIEW-BASED-ACM-MIB (more commonly known as the "VACM MIB") from
[RFC3415]. It also relies on IMPORTS from several other modules.
6.1. Relationship to the VACM MIB
Although the MIB module defined here has a close relationship with
the VACM MIB's vacmSecurityToGroupTable, it in no way changes the
elements of procedure for VACM, nor does it affect any other tables
defined in VACM. See the elements of procedure (below) for details
of how the contents of the vacmSecurityToGroupTable are affected by
this MIB module.
6.2. MIB modules required for IMPORTS
This MIB module employs definitions from [RFC2578], [RFC2579] and
[RFC3411]. The module also relies on the IANA registry defined in
[RFC5590] for transport domain prefixes.
7. Elements of Procedure
The following elements of procedure are formulated in terms of two
types of events: an indication of the establishment of a session, and
an indication that one has ended. These can result in the creation
of entries in the vacmAaaSecurityToGroupTable, which can in turn
trigger creation, update, or deletion of entries in the
vacmSecurityToGroupTable.
There are various possible implementation-specific error cases not
spelled out here, such as running out of memory. By their nature,
recovery in such cases will be implementation-specific. Implementors
are advised to consider fail-safe strategies, e.g., prematurely
terminating access in preference to erroneously perpetuating access.
7.1. Sequencing Requirements
These procedures assume that a transport model, such as [RFC5592],
coordinates session establishment with AAA authentication and
authorization. They rely critically on the receipt by the AAA client
of the RADIUS Management-Policy-Id [RFC5607] Attribute (or its
equivalent) from the RADIUS Access-Accept message (or equivalent).
They also assume that the User-Name [RFC2865] from the RADIUS Access-
Request message (or equivalent) corresponds to an SNMP Security Name
[RFC3411].
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To ensure correct processing of SNMP PDUs, the handling of the
indication of the establishment of a session in accordance with the
elements of procedure below MUST be completed before the
IsAccessAllowed() abstract service interface is invoked for any SNMP
PDUs from that session.
If a session termination indication occurs before all invocations of
the IsAccessAllowed() abstract service interface have completed for
all SNMP PDUs from that session, those remaining invocations MAY
result in denial of access.
7.2. Actions Upon Session Establishment Indication
Four pieces of information are needed to process the session
establishment indication:
o the SnmpSecurityModel [RFC3411] needed as an index into the
vacmSecurityToGroupTable;
o the RADIUS User-Name Attribute or equivalent;
o a session identifier, such as tmSessionID [RFC5590] along with the
prefix for its transport domain, as a definitive identifier of the
transport session that the AAA authorization is tied to;
o the RADIUS Management-Policy-Id Attribute or equivalent
In particular, if either the User-Name or Management-Policy-Id is
absent, invalid, or a zero-length string, no further processing of
the session establishment indication is undertaken.
7.2.1. Creation of Entries in vacmAaaSecurityToGroupTable
Whenever an indication arrives that a new session has been
established, determine whether a corresponding entry exists in the
vacmAaaSecurityToGroupTable. If one does not, create a new row with
the columns populated as follows:
o vacmAaaSecurityModel = value of SnmpSecurityModel corresponding to
the security model in use
o vacmAaaSecurityName = RADIUS User-Name Attribute or equivalent,
the securityName that will be used in invocations of the
isAccessAllowed() abstract service interface;
o vacmAaaTransportModel = the one- to four-character registered
prefix of the transport domain [RFC5590]
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o vacmAaaTransportSessionID = unique (at least within the the scope
of a transport model) session identifier
o vacmAaaGroupName = RADIUS Management-Policy-Id Attribute or
equivalent
Otherwise, if the row already exists, update the vacmAaaGroupName
with the value supplied.
7.2.2. Creation of Entries in vacmSecurityToGroupTable
Whenever an entry is created in the vacmAaaSecurityToGroupTable, the
vacmSecurityToGroupTable is examined to determine whether a
corresponding entry exists there, using the value of
vacmAaaSecurityModel for vacmSecurityModel, and the value of
vacmAaaSecurityName for vacmSecurityName. If no corresponding entry
exists, create one, using the vacmAaaGroupName of the newly created
entry to fill in vacmGroupName, using a value of "volatile" for
vacmSecurityToGroupStorageType, and a value of "active" for
vacmSecurityToGroupStatus.
If a corresponding entry already exists in the
vacmSecurityToGroupTable, and the row's StorageType is anything other
than "volatile", or the RowStatus is anything other than "active",
then a role (group) mapping for this user (principal) has already
been put in place on this system, and will not be overridden.
7.2.3. Update of vacmGroupName
Whenever the value of an instance of vacmAaaGroupName is updated, if
a corresponding entry exists in the vacmSecurityToGroupTable, and
vacmSecurityToGroupStorageType is "volatile" and
vacmSecurityToGroupStatus is "active", update the value of
vacmGroupName with the value from vacmAaaGroupName.
The operational assumption here is that if the row's StorageType is
"volatile", then this entry was probably dynamically created; an
entry created by a security administrator would not normally be given
a StorageType of "volatile". If value being provided by RADIUS (or
other AAA service) is the same as what is already there, this is a
no-op. If the value is different, the new information is understood
as a more recent role (group) assignment for the user, which should
supercede the one currently held there.
7.3. Actions Upon Session Termination Indication
Whenever a RADIUS (or other AAA) authenticated session ends for any
reason, an indication is provided. This indication MUST provide
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means of determining the SnmpSecurityModel, transport domain prefix,
and an identifier for the transport session tied to the AAA
authorization. The manner in which this occurs is implementation
dependent.
7.3.1. Deletion of Entries from vacmAaaSecurityToGroupTable
Entries in the vacmAaaSecurityToGroupTable MUST NOT persist across
system reboots.
When a session has been terminated, the vacmAaaSecurityToGroupTable
is searched for a corresponding entry. A "matching" entry is any
entry for which the SnmpSecurityModel, transport domain prefix, and
session ID match the information associated with the session
termination indication. Any matching entries are deleted. It is
possible that no entries will match; this is not an error, and no
special processing is required in this case.
7.3.2. Deletion of Entries from vacmSecurityToGroupTable
Whenever the last remaining row bearing a particular
(vacmAaaSecurityModel, vacmAaaSecurityName) pair is deleted from the
vacmAaaSecurityToGroupTable, the vacmSecurityToGroupTable is examined
for a corresponding row. If one exists, and if its StorageType is
"volatile" and its RowStatus is "active", that row MUST be deleted as
well. The mechanism to accomplish this task is implementation
specific.
8. Definitions
SNMP-VACM-AAA-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF
MODULE-IDENTITY, OBJECT-TYPE,
mib-2,
Unsigned32 FROM SNMPv2-SMI
SnmpAdminString,
SnmpSecurityModel FROM SNMP-FRAMEWORK-MIB;
snmpVacmAaaMIB MODULE-IDENTITY
LAST-UPDATED "201007060000Z" -- 6 July, 2010
ORGANIZATION "ISMS Working Group"
CONTACT-INFO "WG-email: isms@ietf.org"
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DESCRIPTION "The management and local datastore information
definitions for the AAA-Enabled View-based Access
Control Model for SNMP.
Copyright (c) 2010 IETF Trust and the persons
identified as the document authors. All rights
reserved.
Redistribution and use in source and binary forms,
with or without modification, is permitted pursuant
to, and subject to the license terms contained in,
the Simplified BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating
to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this MIB module is part of RFC XXXX;
see the RFC itself for full legal notices."
REVISION "201007060000Z"
DESCRIPTION "Initial version, published as RFC XXXX."
::= { mib-2 XXX }
vacmAaaMIBObjects OBJECT IDENTIFIER ::= { snmpVacmAaaMIB 1 }
vacmAaaMIBConformance OBJECT IDENTIFIER ::= {snmpVacmAaaMIB 2 }
vacmAaaSecurityToGroupTable OBJECT-TYPE
SYNTAX SEQUENCE OF VacmAaaSecurityToGroupEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "This table provides a listing of all currently
active sessions for which a mapping
of the combination of SnmpSecurityModel and
SecurityName into a GroupName has been provided
by an AAA service. The GroupName (in VACM)
in turn identifies an access control policy
to be used for the corresponding principals."
::= { vacmAaaMIBObjects 1 }
vacmAaaSecurityToGroupEntry OBJECT-TYPE
SYNTAX VacmAaaSecurityToGroupEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "An entry in this table maps the combination of a
SnmpSecurityModel and SecurityName into a GroupName
for a particular session.
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Each entry corresponds to a session.
Entries do not persist across reboots.
When a session is torn down, disconnected,
timed out (e.g. following the RADIUS
Session-Timeout Attribute), or otherwise
terminated for any reason, the corresponding
vacmAaaSecurityToGroupEntry is deleted."
INDEX {
vacmAaaSecurityModel,
vacmAaaSecurityName,
vacmAaaTransportModel,
vacmAaaTransportSessionID
}
::= { vacmAaaSecurityToGroupTable 1 }
VacmAaaSecurityToGroupEntry ::= SEQUENCE
{
vacmAaaSecurityModel SnmpSecurityModel,
vacmAaaSecurityName SnmpAdminString,
vacmAaaTransportModel SnmpAdminString,
vacmAaaTransportSessionID Unsigned32,
vacmAaaGroupName SnmpAdminString
}
vacmAaaSecurityModel OBJECT-TYPE
SYNTAX SnmpSecurityModel(1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "The Security Model associated with the AAA binding
represented by this entry.
This object cannot take the 'any' (0) value."
::= { vacmAaaSecurityToGroupEntry 1 }
vacmAaaSecurityName OBJECT-TYPE
SYNTAX SnmpAdminString (SIZE(1..32))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "The Security Name of the principal associated with
the AAA binding represented by this entry.
In RADIUS environments, this corresponds to
the User-Name Attribute."
::= { vacmAaaSecurityToGroupEntry 2 }
vacmAaaTransportModel OBJECT-TYPE
SYNTAX SnmpAdminString (SIZE(1..4))
MAX-ACCESS not-accessible
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STATUS current
DESCRIPTION "The prefix of this session's transport domain."
::= { vacmAaaSecurityToGroupEntry 3 }
vacmAaaTransportSessionID OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "A specific identifier of the session.
This value MUST be unique among all
currently open sessions within a transport model.
The value has no particular significance other
to distinguish sessions. An example of a suitable
value would be tmSessionID."
::= { vacmAaaSecurityToGroupEntry 4 }
vacmAaaGroupName OBJECT-TYPE
SYNTAX SnmpAdminString (SIZE(1..32))
MAX-ACCESS read-only
STATUS current
DESCRIPTION "The name of the group to which this entry
is to belong. In RADIUS environments this
comes from the RADIUS Management-Policy-Id
Attribute.
This group name is used to set the vacmGroupName
in the corresponding vacmSecurityToGroupEntry."
::= { vacmAaaSecurityToGroupEntry 5 }
-- Conformance information ******************************************
vacmAaaMIBCompliances
OBJECT IDENTIFIER ::= {vacmAaaMIBConformance 1}
vacmAaaMIBGroups
OBJECT IDENTIFIER ::= {vacmAaaMIBConformance 2}
-- compliance statements
vacmAaaMIBBasicCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION "The compliance statement for SNMP engines which
implement the Extensions to the View-based Access
Control Model for use with RADIUS."
MODULE -- this module
MANDATORY-GROUPS { vacmAaaGroup }
::= { vacmAaaMIBCompliances 1 }
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-- units of conformance
vacmAaaGroup OBJECT-GROUP
OBJECTS {
vacmAaaGroupName
}
STATUS current
DESCRIPTION "A collection of objects for supporting the use
of AAA services to provide user / group
mappings for VACM."
::= { vacmAaaMIBGroups 1 }
END
9. Security Considerations
The algorithms in this memo make heuristic use of the StorageType of
entries in the vacmSecurityToGroupTable to distinguish those
provisioned by a security administrator (which would presumably not
be configured as "volatile") from those dynamically generated. In
making this distinction, it assumes that those entries explicitly
provisioned by a security administrator and given a non-"volatile"
status are not to be dynamically over-ridden. Users of this memo
need to be aware of this operational assumption, which, while
reasonable, is not necessarily universally valid. For example, this
situation could also occur if the SNMP security administrator had
mistakenly created these non-volatile entries in error.
The design of VACM ensures that if an unknown policy (group name) is
used in the vacmSecurityToGroupTable, no access is granted. A
consequence of this is that no matter what information is provided by
the AAA server, no user can gain SNMP access rights not already
granted to some group through the VACM configuration.
In order to ensure that the access control policy ultimately applied
as a result of the mechanisms described here is indeed the intended
policy for a given principal using a particular security model, care
needs to be applied in the mapping of the authenticated user
(principal) identity to the securityName used to make the access
control decision. Broadly speaking, there are two approaches to
ensure consistency of identity:
o Entries for the vacmSecurityToGroupTable corresponding to a given
security model are created only through the operation of the
procedures described in this memo. A consequence of this would be
that all such entries would have been created using the RADIUS
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User-Name (or other AAA-authenticated identity) and RADIUS
Management-Policy-Id Attribute (or equivalent).
o Administrative policy allows a matching pre-configured entry to
exist in the vacmSecurityToGroupTable, i.e., an entry with the
corresponding vacmSecurityModel and with a vacmSecurityName
matching the authenticated principal's RADIUS User-Name). In this
case, administrative policy also needs to ensure consistency of
identity between each authenticated principal's RADIUS User-Name
and the administratively configured vacmSecurityName in the
vacmSecurityToGroupTable row entries for that particular security
model.
In the later case, inconsistent re-use of the same name for different
entities or individuals (principals) can cause the incorrect access
control policy to be applied for the authenticated principal,
depending on whether the policy configured using SNMP, or the policy
applied using the procedures of this memo, is the intended policy.
This may result in greater or lesser access rights than the
administrative policy intended. Inadvertent mis-identification in
such cases may be undetectable by the SNMP engine or other software
elements of the managed entity.
There are no management objects defined in this MIB module that have
a MAX-ACCESS clause of read-write and/or read-create. So, if this
MIB module is implemented correctly, then there is no risk that an
intruder can alter or create any management objects of this MIB
module via direct SNMP SET operations.
Some of the readable objects in this MIB module (including some
objects with a MAX-ACCESS of not-accessible, whose values are exposed
as a result access to indexed objects) may be considered sensitive or
vulnerable in some network environments. It is thus important to
control even GET and/or NOTIFY access to these objects and possibly
to even encrypt the values of these objects when sending them over
the network via SNMP. These are the tables and objects and their
sensitivity/vulnerability:
o vacmAaaSecurityToGroupTable - the entire table is potentially
sensitive, since walking the table will reveal user names,
security models in use, session identifiers, and group names.
o vacmAaaSecurityModel - though not-accessible, this is exposed as
an index of vacmAaaGroupName
o vacmAaaSecurityName - though not-accessible, this is exposed as an
index of vacmAaaGroupName
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o vacmAaaTransportSessionID - though not-accessible, this is exposed
as an index of vacmAaaGroupName
o vacmAaaGroupName - since this identifies a security policy and
associates it with a particular user, this is potentially
sensitive.
SNMP versions prior to SNMPv3 did not include adequate security.
Even if the network itself is secure (for example by using IPsec),
even then, there is no control as to who on the secure network is
allowed to access and GET/SET (read/change/create/delete) the objects
in this MIB module.
It is RECOMMENDED that implementers consider the security features as
provided by the SNMPv3 framework (see [RFC3410], section 8),
including full support for the SNMPv3 cryptographic mechanisms (for
authentication and privacy).
Further, deployment of SNMP versions prior to SNMPv3 is NOT
RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and to
enable cryptographic security. It is then a customer/operator
responsibility to ensure that the SNMP entity giving access to an
instance of this MIB module is properly configured to give access to
the objects only to those principals (users) that have legitimate
rights to indeed GET or SET (change/create/delete) them.
10. IANA Considerations
The MIB module in this document uses the following IANA-assigned
OBJECT IDENTIFIER value recorded in the SMI Numbers registry:
Descriptor OBJECT IDENTIFIER value
---------- -----------------------
snmpVacmAaaMIB { mib-2 XXX }
Editor's Note (to be removed prior to publication): the IANA is
requested to assign a value for "XXX" under the 'mib-2' subtree and
to record the assignment in the SMI Numbers registry. When the
assignment has been made, the RFC Editor is asked to replace "XXX"
(here and in the MIB module) with the assigned value and to remove
this note.
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11. Contributors
The following participants from the isms working group contributed to
the development of this document:
o Andrew Donati
o David Harrington
o Jeffrey Hutzelman
o Juergen Schoenwaelder
o Tom Petch
o Wes Hardaker
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, April 1999.
[RFC2580] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Conformance Statements for SMIv2", STD 58, RFC 2580,
April 1999.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, June 2000.
[RFC3411] Harrington, D., Presuhn, R., and B. Wijnen, "An
Architecture for Describing Simple Network Management
Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
December 2002.
[RFC3415] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
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Management Protocol (SNMP)", STD 62, RFC 3415,
December 2002.
[RFC5590] Harrington, D. and J. Schoenwaelder, "Transport Subsystem
for the Simple Network Management Protocol (SNMP)",
RFC 5590, June 2009.
[RFC5607] Nelson, D. and G. Weber, "Remote Authentication Dial-In
User Service (RADIUS) Authorization for Network Access
Server (NAS) Management", RFC 5607, July 2009.
[RFC5608] Narayan, K. and D. Nelson, "Remote Authentication Dial-In
User Service (RADIUS) Usage for Simple Network Management
Protocol (SNMP) Transport Models", RFC 5608, August 2009.
12.2. Informative References
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410, December 2002.
[RFC5592] Harrington, D., Salowey, J., and W. Hardaker, "Secure
Shell Transport Model for the Simple Network Management
Protocol (SNMP)", RFC 5592, June 2009.
Authors' Addresses
Kaushik Narayan
Cisco Systems, Inc.
10 West Tasman Drive
San Jose, CA 95134
USA
Phone: +1 408-526-8168
Email: kaushik_narayan@yahoo.com
David Nelson
Elbrys Networks, Inc.
282 Corporate Drive, Unit #1,
Portsmouth, NH 03801
USA
Phone: +1 603-570-2636
Email: d.b.nelson@comcast.net
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Randy Presuhn (editor)
None
San Jose, CA 95120
USA
Email: randy_presuhn@mindspring.com
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