authentication authorization accounting and auditing open issues for irtf aaaarch working group...
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Authentication Authorization Accounting and Auditing
Open Issues for irtf AAAARCH working group
IWS2000 February 16, 2000
John Vollbrecht
Director, Merit AAA Server Consortium
Merit Network Inc.
AAARCH irtf working group– goals and objectives
• Research rather than engineering group– Long term architecture group, related to AAA working
group• Architecture and models for AAA/A in 9-12 months• Feed full requirements to AAA wg in early 2001
As opposed to
• AAA ietf wg goals –• to have an “interim” protocol requirements by end of March
(Adelaide ietf)• Hope to recharter as a Protocol selection group and have
interim protocol by early 2001
[email protected] IWS2000 !6 Feb.2000
User org AAA
AAA Broker
AAA Broker
Appl with AAA
User org AAA
Appl with AAAAAA Broker
AAA Broker
User
AAA infrastructure – vision for the future
[email protected] IWS2000 !6 Feb.2000
AAA irtf basic concepts
• Focus on inter-organization issue• Service provider and user-organization each “own” policy• Push, Pull, Agent sequences for
Authorization• Brokers and Proxies as intermediaries
between service providers and user-organizations
[email protected] IWS2000 !6 Feb.2000
Brokers and Proxies
• Different types of intermediaries• Brokers aggregate applications and/or “user-orgs”
– Facilitate inter-organization cooperation
• Proxies promote interaction between AAA servers within an administrative domain– Often translate between organization specific and
standard interface
• Much of AAA work deals with how Brokers and Proxies fit with AAA protocols
[email protected] IWS2000 !6 Feb.2000
Brokers and Proxies – Requirements- tentative definitions
• Brokers have business relationship with multiple organizations– Implies enough trust to do business– Perhaps not “complete” trust– Requires audit friendly AAA system
• Proxies interact with AAA servers in the same organization– Implies organizational trust (not network/security trust)– Typically uses
• translate between AAA protocols • aggregate AAA servers in an organization• Interface to AAA servers in other organizations
[email protected] IWS2000 !6 Feb.2000
AAAARCH –Open Issues
• Data representation• Data security• Interaction between accounting and authorization• State maintenance with no single point of failure• Distributed policy
– Storage/ evaluation/ enforcement
– Policy description
• Auditing requirements
[email protected] IWS2000 !6 Feb.2000
Data Representation
• Groups of objects• Groups of groups• Integrity by group• Identify originating and destination server(s)• Data Object contents could be
– Policy description– Policy “data”– Policy evaluation
• Possibly Self defining syntax for objects
[email protected] IWS2000 !6 Feb.2000
Data Objects
Service AAA
Broker AAA
User-org AAA
(DO1) (AAA-HDR) (DO1) (DO2)(AAA-HDR)
(AAA-HDR)(DO3)(AAA-HDR)(DO3)(DO4)
Data Object Security
• Integrity– Role of mac vs. signatures– Role of intermediary
• Broker
• Trusted 3rd party
– Performance and business model
[email protected] IWS2000 !6 Feb.2000
Data Object Security
• Confidentiality– When is it required
• Examples– Clear text password
– Session key for FA/HA in MobileIP
– What is required• Some external authority trusted by originator and
receiver of confidential data object
[email protected] IWS2000 !6 Feb.2000
Accounting and Authorization
• Authorization can include Accounting Policy
• Accounting to demonstrate that requested policy was implemented ( i.e. that QOS requested was delivered)
• Requirement for a “session id” to identify Accounting and Authorization activity for the same session
[email protected] IWS2000 !6 Feb.2000
State Maintenance
• State is what is known about a session – often most important is whether the session is currently “up”
• Information about state of session may be maintained in multiple AAA servers
• There is one source of authoritative information about each state element of the session
• Making sure that what is kept in AAA server matches authoritative source is tricky and has led to systems with difficulty doing fail over between a primary and backup server
[email protected] IWS2000 !6 Feb.2000
Distributed Session State(proposal)
NAS
Primary AAA Server
Backup AAA Server
Request/reply
State update
Sess state
Sess state
State request
[email protected] IWS2000 !6 Feb.2000
Distributed Policy
• Policy Description– Repository maintained by organizational owner
• Policy Data– Data to be evaluated by policy
• Policy Enforcement– Doing what the Policy describes
• Owner of policy may not be owner of Policy Data• Enforcement of Policy decision may be by
different organization than the one defining policy
[email protected] IWS2000 !6 Feb.2000
Distributed Policy
User-org AAA
Broker AAA
Application AAA
Policy Repository
Policy Repository
Policy Repository
User info db
Broker agreements db
Application state dbDevice
PEP
Auditing
• With multi-organization process, each organization must trust that others are doing what is expected
• Auditing verifies that processes are reasonable, appropriate for expected results
• Equivalent to what CPA would require for standard business systems
• Expands network management to multi-organization process
[email protected] IWS2000 !6 Feb.2000
Some Audit Mechanisms
• Logging signed requests and session status records
• Logging by trusted 3rd party of appropriate records
• Real time “check” that appropriate programs are running
• Comparing log entries from cooperating servers
[email protected] IWS2000 !6 Feb.2000
Summary
• Active Group working on AAA issues• Goal is to find and define a simple mechanism that
permits complex services• Open mail group• We encourage interested people to join the group
(mail to [email protected] or [email protected])
• Questions/ comments? (Thanks)