PANA Working Group Y. Ohba
Internet-Draft V. Fajardo
Expires: January 9, 2005 TARI
R. Lopez
Univ. of Murcia
July 11, 2004
State Machines for Protocol for Carrying Authentication for Network
Access (PANA)
draft-ohba-pana-statemachine-00
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Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
This document defines the conceptual state machines for the Protocol
for Carrying Authentication for Network Access (PANA). The state
machines consist of the PANA Client (PaC) state machine and the PANA
Authentication Agent (PAA) state machine. The two state machines
show how PANA can interface to EAP state machines and can be
implemented with supporting various features including separate NAP
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and ISP authentications, ISP selection and mobility optimization.
The state machines and associated model are informative only.
Implementations may achieve the same results using different methods.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Interface Between PANA and EAP . . . . . . . . . . . . . . . . 5
3. Document Authority . . . . . . . . . . . . . . . . . . . . . . 7
4. Notations . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Common Rules . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 Common Procedures . . . . . . . . . . . . . . . . . . . . 10
5.2 Common Variables . . . . . . . . . . . . . . . . . . . . . 11
5.3 Constants . . . . . . . . . . . . . . . . . . . . . . . . 12
5.4 Common Message Initialization Rules . . . . . . . . . . . 13
5.5 Common State Transitions . . . . . . . . . . . . . . . . . 13
6. PaC State Machine . . . . . . . . . . . . . . . . . . . . . . 14
6.1 Interface between PaC and EAP Peer . . . . . . . . . . . . 14
6.1.1 Delivering EAP Messages from PaC to EAP Peer . . . . . 14
6.1.2 Delivering EAP Responses from EAP Peer to PaC . . . . 14
6.1.3 EAP Restart Notification from PaC to EAP Peer . . . . 14
6.1.4 EAP Authentication Result Notification from EAP
Peer to PaC . . . . . . . . . . . . . . . . . . . . . 14
6.1.5 Alternate Failure Notification from PaC to EAP Peer . 15
6.1.6 EAP Invalid Message Notification from EAP Peer to
PaC . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.2 Variables . . . . . . . . . . . . . . . . . . . . . . . . 15
6.3 Procedures . . . . . . . . . . . . . . . . . . . . . . . . 17
6.4 PaC State Transition Table . . . . . . . . . . . . . . . . 17
7. PAA State Machine . . . . . . . . . . . . . . . . . . . . . . 27
7.1 Interface between PAA and EAP Authenticator . . . . . . . 27
7.1.1 EAP Restart Notification from PAA to EAP
Authenticator . . . . . . . . . . . . . . . . . . . . 27
7.1.2 Delivering EAP Responses from PAA to EAP
Authenticator . . . . . . . . . . . . . . . . . . . . 27
7.1.3 Delivering EAP Messages from EAP Authenticator to
PAA . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.1.4 EAP Authentication Result Notification from EAP
Authenticator to PAA . . . . . . . . . . . . . . . . . 27
7.2 Variables . . . . . . . . . . . . . . . . . . . . . . . . 28
7.3 Procedures . . . . . . . . . . . . . . . . . . . . . . . . 30
7.4 PAA State Transition Table . . . . . . . . . . . . . . . . 31
8. Implementation Considerations . . . . . . . . . . . . . . . . 41
8.1 Interface exposed by PANA to the Host System . . . . . . . 41
8.2 PAA Interface to EP . . . . . . . . . . . . . . . . . . . 41
8.3 Multicast Traffic . . . . . . . . . . . . . . . . . . . . 42
9. Security Considerations . . . . . . . . . . . . . . . . . . . 43
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 44
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11. References . . . . . . . . . . . . . . . . . . . . . . . . . 45
11.1 Normative References . . . . . . . . . . . . . . . . . . . . 45
11.2 Informative References . . . . . . . . . . . . . . . . . . . 45
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 45
Intellectual Property and Copyright Statements . . . . . . . . 47
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1. Introduction
This document defines the state machines for Protocol Carrying
Authentication for Network Access (PANA) [I-D.ietf-pana-pana]. There
are state machines for the PANA client (PaC) and for the PANA
Authentication Agent (PAA). Each state machine is specified through
a set of variables, procedures and a state transition table.
A PANA protocol execution consists of several exchanges to carry
authentication information. Specifically, EAP PDUs are transported
inside PANA PDUs between PaC and PAA, that is PANA represents a lower
layer for EAP protocol. Thus, a PANA state machine bases its
execution on an EAP state machine execution and vice versa. Thus
this document also shows for each of PaC and PAA an interface between
an EAP state machine and a PANA state machine and how this interface
allows to exchange information between them. Thanks to this
interface, a PANA state machine can be informed about several events
generated in an EAP state machine and make its execution conditional
to its events.
The details of EAP state machines are out of the scope of this
document. Additional information can be found in
[I-D.ietf-eap-statemachine]. Nevertheless PANA state machines
presented here have been coordinated with state machines shown by
[I-D.ietf-eap-statemachine].
This document, apart from defining PaC and PAA state machines and
their interfaces to EAP state machines (running on top of PANA),
provides some implementation considerations, taking into account that
it is not a specification but an implementation guideline.
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2. Interface Between PANA and EAP
PANA carries EAP messages exchanged between an EAP peer and an EAP
authenticator (see Figure 1). Thus a PANA state machine must
interact with an EAP state machine.
Two state machines are defined in this document : the PaC state
machine (see Section 6) and the PAA state machine (see Section 7).
The definition of each state machine consists of a set of variables,
procedures and a state transition table. A subset of these variables
and procedures defines the interface between a PANA state machine and
an EAP state machine and the state transition table defines the PANA
state machine behavior based on results obtained through them.
On the one hand, the PaC state machine interacts with an EAP peer
state machine in order to carry out the PANA protocol on the PaC
side. On the other hand, the PAA state machine interacts with an EAP
authenticator state machine to run the PANA protocol on the PAA side.
Peer |EAP Auth
EAP <---------|------------> EAP
^ | | ^ |
EAP-Request | | | EAP-Response | | EAP-Request
EAP-Success | |EAP-Response | | |EAP-Success
EAP-Failure | v |PANA | vEAP-Failure
PaC <---------|------------> PAA
Figure 1: Interface between PANA and EAP
Thus two interfaces are needed between PANA state machines and EAP
state machines, namely:
o Interface between the PaC state machine and the EAP peer state
machine
o Interface between the PAA state machine and the EAP authenticator
state machine
In general, the PaC state machine presents EAP messages (EAP-Request,
EAP-Success and EAP-Failure messages) to the EAP peer state machine
through the interface. The EAP peer state machine processes these
messages and sends EAP messages (EAP-Response messages) through the
PaC state machine that is responsible for actually transmitting this
message.
On the other hand, the PAA state machine presents response messages
(EAP-Response messages) to the EAP authenticator state machine
through interface defined between them. The EAP authenticator
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processes these messages and generate EAP messages (EAP-Request,
EAP-Success and EAP-Failure messages) that are send to the PAA state
machine to be sent.
For example, [I-D.ietf-eap-statemachine] specifies four interfaces to
lower layers: (i) an interface between the EAP peer state machine and
a lower layer, (ii) an interface between the EAP standalone
authenticator state machine and a lower layer, (iii) an interface
between the EAP full authenticator state machine and a lower layer
and (iv) an interface between the EAP backend authenticator state
machine and a lower layer. In this document, the PANA protocol is
the lower layer of EAP and only the first three interfaces are of
interest to PANA. The second and third interfaces are the same. In
this regard, the EAP standalone authenticator or the EAP full
authenticator and its state machine in [I-D.ietf-eap-statemachine]
are referred to as the EAP authenticator and the EAP authenticator
state machine, respectively, in this document. If an EAP peer and an
EAP authenticator follow the state machines defined in
[I-D.ietf-eap-statemachine], the interfaces between PANA and EAP
could be based on that document. Detailed definition of interfaces
between PANA and EAP are described in the subsequent sections.
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3. Document Authority
When a discrepancy occurs between any part of this document and any
of the related documents ([I-D.ietf-pana-pana],
[I-D.ietf-eap-statemachine] the latter (the other documents) are
considered authoritative and takes precedence.
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4. Notations
The following state transition tables are completed mostly based on
the conventions specified in [I-D.ietf-eap-statemachine]. The
complete text is described below.
State transition tables are used to represent the operation of the
protocol by a number of cooperating state machines each comprising a
group of connected, mutually exclusive states. Only one state of
each machine can be active at any given time.
All permissible transitions from a given state to other states and
associated actions performed when the transitions occur are
represented by using triplets of (exit condition, exit action, exit
state). All conditions are expressions that evaluate to TRUE or
FALSE; if a condition evaluates to TRUE, then the condition is met.
A state "ANY" is a wildcard state that matches the current state in
each state machine. The exit conditions of a wildcard state are
evaluated after all other exit conditions of specific to the current
state are met.
On exit from a state, the procedures defined for the state and the
exit condition are executed exactly once, in the order that they
appear on the page. (Note that the procedures defined in
[I-D.ietf-eap-statemachine] are executed on entry to a state, which
is one major difference from this document.) Each procedure is
deemed to be atomic; i.e., execution of a procedure completes before
the next sequential procedure starts to execute. No procedures
execute outside of a state block. The procedures in only one state
block execute at a time, even if the conditions for execution of
state blocks in different state machines are satisfied, and all
procedures in an executing state block complete execution before the
transition to and execution of any other state block occurs, i.e.,
the execution of any state block appears to be atomic with respect to
the execution of any other state block and the transition condition
to that state from the previous state is TRUE when execution
commences. The order of execution of state blocks in different state
machines is undefined except as constrained by their transition
conditions. A variable that is set to a particular value in a state
block retains this value until a subsequent state block executes a
procedure that modifies the value.
On completion of the transition from the previous state to the
current state, all exit conditions for the current state (including
exit conditions defined for the wildcard state) are evaluated
continuously until one of the conditions is met.
Any event variable is set to TRUE when the corresponding event occurs
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and set to FALSE immediately after completion of the action
associated with the current state and the event.
The interpretation of the special symbols and operators used is
defined in [I-D.ietf-eap-statemachine].
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5. Common Rules
There are following procedures, variables, message initializing rules
and state transitions that are common to both the PaC and PAA state
machines.
Throughout this document, the character string "PANA_MESSAGE_NAME"
matches any one of the abbreviated PANA message names, i.e., "PDI",
"PSR", "PSA", "PAR", "PAN", "PBR", "PBA", "PFER", "PFEA", "PTR",
"PTA", "PRAR", "PRAA", "PAUR", "PAUA" and "PER".
5.1 Common Procedures
None()
A null procedure, i.e., nothing is done.
Disconnect()
A procedure to delete the PANA session as well as the
corresponding EAP session and authorization state.
boolean Authorize()
A procedure to create or modify authorization state. It returns
TRUE if authorization is successful. Otherwise, it returns FALSE.
It is assumed that Authorize() procedure of PaC state machine
always returns TRUE.
Tx:PANA_MESSAGE_NAME()
A procedure to send a PANA message to its peering PANA entity.
TxEAP()
A procedure to send an EAP message to the EAP state machine it
interfaces to.
RtxTimerStart()
A procedure to start the retransmission timer, reset RTX_COUNTER
variable to zero and set an appropriate value to RTX_MAX_NUM
variable.
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RtxTimerStop()
A procedure to stop the retransmission timer.
SessionTimerStart()
A procedure to start PANA session timer.
Retransmit()
A procedure to retransmit a PANA message and increment RTX_COUNTER
by one(1).
EAP_Restart()
A procedure to (re)start an EAP conversation.
void PANA_MESSAGE_NAME.insert_avp("AVP_NAME")
A procedure to insert an AVP of the specified AVP name in the
specified PANA message.
boolean PANA_MESSAGE_NAME.exist_avp("AVP_NAME")
A procedure that checks whether an AVP of the specified AVP name
exists in the specified PANA message and returns TRUE if the
specified AVP is found, otherwise returns FALSE.
boolean key_available()
A procedure to check whether the PANA session has a PANA_MAC_KEY.
If the state machine already have a PANA_MAC_KEY, it returns TRUE.
If the state machine does not have a PANA_MAC_KEY, it tries to
retrieve a AAA-Key from the EAP entity. If a AAA-Key is
retrieved, it computes a PANA_MAC_KEY from the AAA-Key and returns
TRUE. Otherwise, it returns FALSE.
5.2 Common Variables
PANA_MESSAGE_NAME.S_flag
This variable contains the S-Flag value of the specified PANA
message.
PBR.RESULT_CODE
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This variable contains the Result-Code AVP value in the
PANA-Bind-Request message in process.
RTX_COUNTER
This variable contains the current number of retransmissions of
the outstanding PANA message.
Rx:PANA_MESSAGE_NAME
This event variable is set to TRUE when the specified PANA message
is received from its peering PANA entity.
RTX_TIMEOUT
This event variable is set to TRUE when the retransmission timer
is expired.
EAP_REAUTH
This event variable is set to TRUE when an initiation of EAP-based
re-authentication is triggered.
FAST_REAUTH
This event variable is set to TRUE when initiation of
re-authentication based on PRAR-PRAA exchange is triggered.
SESS_TIMEOUT
This event is variable is set to TRUE when the session timer is
expired.
ABORT_ON_1ST_EAP_FAILURE
This variable indicates whether the PANA session is immediately
terminated when the 1st EAP authentication fails.
ANY
This event variable is set to TRUE when any event occurs.
5.3 Constants
RTX_MAX_NUM
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Configurable maximum for how many retransmissions should be
attempted before aborting.
5.4 Common Message Initialization Rules
When a message is prepared for sending, it is initialized as follows:
o For a request message, R-flag of the header is set. Otherwise,
R-flag is not set.
o S-flag and N-flag of the header are not set.
o AVPs that are mandatory included in a message are inserted with
appropriate values set.
5.5 Common State Transitions
The following transitions can occur at any state.
----------
State: ANY
----------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - (Reach maximum number of retransmission)- -
RTX_TIMEOUT && Retransmit(); (no change)
RTX_COUNTER<
RTX_MAX_NUM
RTX_TIMEOUT && Disconnect(); CLOSED
RTX_COUNTER>=
RTX_MAX_NUM
SESS_TIMEOUT Disconnect(); CLOSED
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-------------
State: CLOSED
-------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - -(Session termination initiated by PaC) - - - - -
ANY None(); CLOSED
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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6. PaC State Machine
6.1 Interface between PaC and EAP Peer
This interface defines the interactions between a PaC and an EAP
peer. The interface serves as a mechanism to deliver EAP messages
for the EAP peer. It allows the EAP peer to receive EAP requests and
send EAP responses via the PaC. It also provides a mechanism to
notify the EAP peer of PaC events and a mechanism to receive
notification of EAP peer events. The EAP message delivery mechanism
as well as the event notification mechanism in this interface have
direct correlation with the PaC state transition table entries.
These message delivery and event notifications mechanisms occur only
within the context of their associated states or exit actions.
6.1.1 Delivering EAP Messages from PaC to EAP Peer
TxEAP() procedure in the PaC state machine serves as the mechanism to
deliver EAP requests contained in PANA-Auth-Request messages to the
EAP peer. This procedure is enabled only after an EAP restart event
is notified to the EAP peer. In the case where the EAP peer follows
the EAP peer state machine defined in [I-D.ietf-eap-statemachine],
TxEAP() procedure sets eapReq variable of the EAP peer state machine
and puts the EAP request in eapReqData variable of the EAP peer state
machine.
6.1.2 Delivering EAP Responses from EAP Peer to PaC
An EAP response is delivered from the EAP peer to the PaC via
EAP_RESPONSE event variable. The event variable is set when the EAP
peer passes the EAP response to its lower-layer. In the case where
the EAP peer follows the EAP peer state machine defined in
[I-D.ietf-eap-statemachine], EAP_RESPONSE event variable refers to
eapResp variable of the EAP peer state machine and the EAP response
is contained in eapRespData variable of the EAP peer state machine.
6.1.3 EAP Restart Notification from PaC to EAP Peer
The EAP peer state machine defined in [I-D.ietf-eap-statemachine] has
an initialization procedure before receiving an EAP request. To
initialize the EAP state machine, the PaC state machine defines an
event notification mechanism to send an EAP (re)start event to the
EAP peer. The event notification is done via EAP_Restart() procedure
in the initialization action of the PaC state machine.
6.1.4 EAP Authentication Result Notification from EAP Peer to PaC
In order for the EAP peer to notify the PaC of an EAP authentication
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result, EAP_SUCCESS and EAP_FAILURE event variables are defined. In
the case where the EAP peer follows the EAP peer state machine
defined in [I-D.ietf-eap-statemachine], EAP_SUCCESS and EAP_FAILURE
event variables refer to eapSuccess and eapFail variables of the EAP
peer state machine, respectively. In this case, if EAP_SUCCESS event
variable is set to TRUE and a AAA-Key is generated by the EAP
authentication method in use, eapKeyAvailable variable is set to TRUE
and eapKeyData variable contains the AAA-Key. Note that EAP_SUCCESS
and EAP_FAILURE event variables may be set to TRUE even before the
PaC receives a PBR or a PFER from the PAA.
6.1.5 Alternate Failure Notification from PaC to EAP Peer
alt_reject() procedure in the PaC state machine serves as the
mechanism to deliver an authentication failure event to the EAP peer
without accompanying an EAP message. In the case where the EAP peer
follows the EAP peer state machine defined in
[I-D.ietf-eap-statemachine], alt_reject() procedure sets altReject
variable of the EAP peer state machine. Note that the EAP peer state
machine in [I-D.ietf-eap-statemachine] also defines altAccept
variable, however, it is never used in PANA in which EAP-Success
messages are reliably delivered by PANA-Bind exchange.
6.1.6 EAP Invalid Message Notification from EAP Peer to PaC
In order for the EAP peer to notify the PaC of a receipt of an
invalid EAP message, EAP_INVALID_MSG event variable is defined. In
the case where the EAP peer follows the EAP peer state machine
defined in [I-D.ietf-eap-statemachine], EAP_INVALID_MSG event
variable refers to eapNoResp variable of the EAP peer state machine.
6.2 Variables
SEPARATE
This variable indicates whether the PaC desires NAP/ISP separate
authentication.
1ST_EAP
This variable indicates whether the 1st EAP authentication is
success, failure or yet completed.
TERMINATE
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This event variable is set to TRUE when initiation of PANA session
termination is triggered.
AUTH_USER
This event variable is set to TRUE when initiation of EAP-based
(re-)authentication is triggered by the application.
MOBILITY
This variable indicates whether the mobility handling feature
described in [I-D.ietf-pana-pana] is supported.
PANA_SA_RESUMED
This variable indicates whether the PANA SA of a previous PANA
session was resumed during the discovery and initial handshake.
EAP_SUCCESS
This event variable is set to TRUE when the EAP peer determines
that EAP conversation completes with success.
EAP_FAILURE
This event variable is set to TRUE when the EAP peer determines
that EAP conversation completes with failure.
EAP_RESPONSE
This event variable is set to TRUE when the EAP peer delivers an
EAP Response to the PaC. This event accompanies an EAP-Response
message received from the EAP peer.
EAP_INVALID_MSG
This event variable is set to TRUE when the EAP peer silently
discards an EAP message. This event does not accompany any EAP
message.
UPDATE_DEVICE_ID
This event variable is set to TRUE when there is a change in the
device identifier of the PaC.
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UPDATE_POPA
This event variable is set to TRUE when there is a change in the
POPA of the PaC.
6.3 Procedures
boolean choose_isp()
This procedure returns TRUE when the PaC chooses one ISP,
otherwise returns FALSE.
boolean resume_pana_sa()
This procedure returns TRUE when a PANA SA for a previously
established PANA Session is resumed, otherwise returns FALSE.
Once a PANA SA is resumed, key_available() procedure must return
TRUE.
void alt_reject()
This procedure informs the EAP peer of an authentication failure
event without accompanying an EAP message.
6.4 PaC State Transition Table
------------------------------
State: OFFLINE (Initial State)
------------------------------
Initialization Action:
SEPARATE=Set|Unset;
1ST_EAP=Unset;
RtxTimerStop();
PANA_SA_RESUMED=Unset;
EAP_Restart();
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - (PSR processing) - - - - - - - - - - -
Rx:PSR && RtxTimerStop(); WAIT_EAP_MSG_
PSR.exist_avp TxEAP(); IN_DISC
("EAP-Payload") SEPARATE=Unset;
Rx:PSR && RtxTimerStop(); WAIT_PAA
!PSR.exist_avp PSA.insert_avp
("EAP-Payload") && ("Session-Id");
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MOBILITY==Set && PSA.insert_avp("Nonce");
resume_pana_sa() && PANA_SA_RESUMED=Set;
PSR.exist_avp PSA.insert_avp("Cookie");
("Cookie") PSA.insert_avp("MAC");
Tx:PSA();
RtxTimerStart();
SEPARATE=Unset;
Rx:PSR && RtxTimerStop(); WAIT_PAA
!PSR.exist_avp PSA.insert_avp
("EAP-Payload") && ("Session-Id");
MOBILITY==Set && PSA.insert_avp("Nonce");
resume_pana_sa() && PSA.insert_avp("MAC");
!PSR.exist_avp Tx:PSA();
("Cookie") PANA_SA_RESUMED=Set;
Rx:PSR && RtxTimerStop(); WAIT_PAA
!PSR.exist_avp if (choose_isp())
("EAP-Payload") && PSA.insert_avp("ISP");
(MOBILITY==Unset || PSA.S_flag=1;
!resume_pana_sa()) && PSA.insert_avp("Cookie");
PSR.S_flag==1 && Tx:PSA();
SEPARATE==Set && RtxTimerStart();
PSR.exist_avp
("Cookie")
Rx:PSR && RtxTimerStop(); WAIT_PAA
!PSR.exist_avp if (choose_isp())
("EAP-Payload") && PSA.insert_avp("ISP");
(MOBILITY==Unset || PSA.S_flag=1;
!resume_pana_sa()) && Tx:PSA();
PSR.S_flag==1 &&
SEPARATE==Set &&
!PSR.exist_avp
("Cookie")
Rx:PSR && RtxTimerStop(); WAIT_PAA
!PSR.exist_avp if (choose_isp())
("EAP-Payload") && PSA.insert_avp("ISP");
(MOBILITY==Unset || PSA.insert_avp("Cookie");
!resume_pana_sa()) && Tx:PSA();
(PSA.S_flag!=1 || RtxTimerStart();
SEPARATE==Unset) && SEPARATE=Unset;
PSR.exist_avp
("Cookie")
Rx:PSR && RtxTimerStop(); WAIT_PAA
!PSR.exist_avp if (choose_isp())
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("EAP-Payload") && PSA.insert_avp("ISP");
(MOBILITY==Unset || Tx:PSA();
!resume_pana_sa()) && SEPARATE=Unset;
(PSA.S_flag!=1 ||
SEPARATE==Unset) &&
!PSR.exist_avp
("Cookie")
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - -(Authentication trigger from application) - - -
AUTH_USER Tx:PDI(); OFFLINE
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
---------------------------
State: WAIT_EAP_MSG_IN_DISC
---------------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - (Return PSA with EAP-Payload) - - - - - -
EAP_RESPONSE PSA.insert_avp WAIT_PAA
("EAP-Payload"))
Tx:PSA();
EAP_INVALID_MSG None(); OFFLINE
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
---------------
State: WAIT_PAA
---------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - -(PAR-PAN exchange) - - - - - - - -
Rx:PAR RtxTimerStop(); WAIT_EAP_MSG
TxEAP();
PANA_SA_RESUMED=Unset;
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -(1st EAP result) - - - - - - - - -
Rx:PFER && 1ST_EAP=Success; WAIT_1ST_EAP_RESULT
1ST_EAP==Unset && TxEAP();
SEPARATE==Set &&
PFER.RESULT_CODE==
PANA_SUCCESS &&
PFER.S_flag==1
Rx:PFER && 1ST_EAP=Failure; WAIT_1ST_EAP_RESULT
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1ST_EAP==Unset && TxEAP();
SEPARATE==Set &&
PFER.RESULT_CODE!=
PANA_SUCCESS &&
PFER.S_flag==1 &&
ABORT_ON_1ST_EAP_FAILURE
==Unset &&
PFER.exit_avp
("EAP-Payload")
Rx:PFER && 1ST_EAP=Failure; WAIT_1ST_EAP_RESULT
1ST_EAP==Unset && alt_reject();
SEPARATE==Set &&
PFER.RESULT_CODE!=
PANA_SUCCESS &&
PFER.S_flag==1 &&
ABORT_ON_1ST_EAP_FAILURE
==Unset &&
!PFER.exit_avp
("EAP-Payload")
Rx:PFER && 1ST_EAP=Failure; WAIT_1ST_EAP_
1ST_EAP==Unset && TxEAP(); RESULT_CLOSED
SEPARATE==Set &&
PFER.RESULT_CODE!=
PANA_SUCCESS &&
(PFER.S_flag==0 ||
ABORT_ON_1ST_EAP_FAILURE
==Set) &&
PFER.exist_avp
("EAP-Payload")
Rx:PFER && 1ST_EAP=Failure; WAIT_1ST_EAP_
1ST_EAP==Unset && alt_reject(); RESULT_CLOSED
SEPARATE==Set &&
PFER.RESULT_CODE!=
PANA_SUCCESS &&
(PFER.S_flag==0 ||
ABORT_ON_1ST_EAP_FAILURE
==Set) &&
!PFER.exist_avp
("EAP-Payload")
Rx:PBR && TxEAP(); WAIT_EAP_RESULT
1ST_EAP==Unset &&
SEPARATE==Unset &&
PBR.RESULT_CODE==
PANA_SUCCESS &&
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PANA_SA_RESUMED!=Set
Rx:PBR && PBA.insert_avp("Key-Id"); OPEN
1ST_EAP==Unset && PBA.insert_avp("MAC");
SEPARATE==Unset && TxPBA();
PBR.RESULT_CODE== Authorize();
PANA_SUCCESS && SessionTimerStart();
PANA_SA_RESUMED==Set &&
PBR.exist_avp
("Nonce") &&
PBR.exist_avp
("Key-Id") &&
PBR.exist_avp
("MAC")
Rx:PBR && TxEAP(); WAIT_EAP_RESULT_
1ST_EAP==Unset && CLOSE
SEPARATE==Unset &&
PBR.RESULT_CODE!=
PANA_SUCCESS &&
PBR.exist_avp
("EAP-Payload")
Rx:PBR && alt_reject(); WAIT_EAP_RESULT_
1ST_EAP==Unset && CLOSE
SEPARATE==Unset &&
PBR.RESULT_CODE!=
PANA_SUCCESS &&
!PBR.exist_avp
("EAP-Payload")
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -(2nd EAP result) - - - - - - - - -
Rx:PBR && TxEAP(); WAIT_EAP_RESULT
1ST_EAP==Success &&
PBR.RESULT_CODE==
PANA_SUCCESS &&
PBR.exist_avp
("EAP-Payload");
Rx:PBR && alt_reject(); WAIT_EAP_RESULT
1ST_EAP==Success &&
PBR.RESULT_CODE==
PANA_SUCCESS &&
!PBR.exist_avp
("EAP-Payload");
Rx:PBR && TxEAP(); WAIT_EAP_RESULT
1ST_EAP==Success &&
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PBR.RESULT_CODE!=
PANA_SUCCESS &&
PBR.exist_avp
("EAP-Payload")
Rx:PBR && alt_reject(); WAIT_EAP_RESULT
1ST_EAP==Success &&
PBR.RESULT_CODE!=
PANA_SUCCESS &&
!PBR.exist_avp
("EAP-Payload")
Rx:PBR && TxEAP(); WAIT_EAP_RESULT
1ST_EAP==Failure &&
PBR.RESULT_CODE==
PANA_SUCCESS
Rx:PBR && TxEAP() WAIT_EAP_RESULT_
1ST_EAP==Failure && CLOSE
PBR.RESULT_CODE!=
PANA_SUCCESS &&
PBR.exist_avp
("EAP-Payload")
Rx:PBR && alt_reject() WAIT_EAP_RESULT_
1ST_EAP==Failure && CLOSE
PBR.RESULT_CODE!=
PANA_SUCCESS &&
!PBR.exist_avp
("EAP-Payload")
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-------------------
State: WAIT_EAP_MSG
-------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - (Return PSA)- - - - - - - - - - - -
EAP_RESPONSE if (key_available()) WAIT_PAA
PAN.insert_avp("MAC");
PAN.S_flag=PAR.S_flag;
PAN.N_flag=PAR.N_flag;
Tx:PAN();
EAP_INVALID_MSG || None(); WAIT_PAA
EAP_SUCCESS ||
EAP_FAILURE
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------------
State: WAIT_EAP_RESULT
----------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - (Return PSA)- - - - - - - - - - - -
EAP_SUCCESS && PBA.insert_avp("MAC"); OPEN
PBR.exist_avp PBA.insert_avp("Key-Id");
("Key-Id") Tx:PBA();
Authorize();
SessionTimerStart();
EAP_SUCCESS && if (key_available()) OPEN
!PBR.exist_avp PBA.insert_avp("MAC");
("Key-Id") Tx:PBA();
SessionTimerStart();
Authorize();
EAP_FAILURE if (key_available()) OPEN
PBA.insert_avp("MAC");
Tx:PBA();
EAP_INVALID_MSG None(); WAIT_PAA
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------------------
State: WAIT_EAP_RESULT_CLOSE
----------------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - (Return PSA)- - - - - - - - - - - -
EAP_SUCCESS && PBA.insert_avp("MAC"); CLOSED
PBR.exist_avp PBA.insert_avp("Key-Id");
("Key-Id") Tx:PBA();
Disconnect();
EAP_SUCCESS && if (key_available()) CLOSED
!PBR.exist_avp PBA.insert_avp("MAC");
("Key-Id") Tx:PBA();
Disconnect();
EAP_FAILURE Tx:PBA(); CLOSED
Disconnect();
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EAP_INVALID_MSG None(); WAIT_PAA
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--------------------------
State: WAIT_1ST_EAP_RESULT
--------------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - (Return PSA)- - - - - - - - - - - -
EAP_SUCCESS && PFEA.insert_avp("Key-Id"); WAIT_PAA
PFER.exist_avp PFEA.S_flag=1;
("Key-Id") PFEA.N_flag=PFER.N_flag;
PFEA.insert_avp("MAC");
Tx:PFEA();
(EAP_SUCCESS && if (key_available()) WAIT_PAA
!PFER.exist_avp PFEA.insert_avp("MAC");
("Key-Id")) || PFEA.S_flag=1;
EAP_FAILURE PFEA.N_flag=PFER.N_flag;
Tx:PFEA();
EAP_INVALID_MSG None(); WAIT_PAA
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--------------------------------
State: WAIT_1ST_EAP_RESULT_CLOSE
--------------------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - (Return PSA)- - - - - - - - - - - -
EAP_SUCCESS && PFEA.insert_avp("Key-Id"); CLOSED
PFER.exist_avp PFEA.S_flag=0;
("Key-Id") PFEA.N_flag=0;
PFEA.insert_avp("MAC");
Tx:PFEA();
Disconnect();
(EAP_SUCCESS && if (key_available()) CLOSED
!PFER.exist_avp PFEA.insert_avp("MAC");
("Key-Id")) || PFEA.S_flag=0;
EAP_FAILURE PFEA.N_flag=0;
Tx:PFEA();
Disconnect();
EAP_INVALID_MSG None(); WAIT_PAA
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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-----------
State: OPEN
-----------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- (re-authentication based on PRAR-PRAA exchange initiated by PAA)
Rx:PRAR if (key_available()) OPEN
PRAA.insert_avp("MAC");
Tx:PRAA();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- (re-authentication based on PRAR-PRAA exchange initiated by PaC)
FAST_REAUTH if (key_available()) WAIT_PRAA
PRAR.insert_avp("MAC");
Tx:PRAR();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - (EAP-based re-authentication initiated by PaC)- - - - -
EAP_REAUTH PDI.insert_avp WAIT_PAA
("Session-Id");
RtxTimerStart();
1ST_EAP=Unset;
PANA_SA_RESUMED=Unset;
Tx:PDI();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - -(EAP-based re-authentication initiated by PAA) - -
Rx:PAR SEPARATE=Set|Unset; WAIT_EAP_MSG
1ST_EAP=Unset;
PANA_SA_RESUMED=Unset;
TxEAP();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - -(Session termination initiated by PAA) - - - - - -
Rx:PTR if (key_available()) CLOSED
PTA.insert_avp("MAC");
Tx:PTA();
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - -(Session termination initiated by PaC) - - - - - -
TERMINATE if (key_available()) SESS_TERM
PTR.insert_avp("MAC");
Tx:PTR();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - -(Address update) - - - - - - - - - - -
UPDATE_DEVICE_ID || if (UPDATE_DEVICE_ID) WAIT_PAUA
UPDATE_POPA PAUR.insert_avp
("Device-Id");
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if (UPDATE_POPA)
PAUR.insert_avp
("IP-Address");
if (key_available())
PAUR.insert_avp("MAC");
Tx:PAUR();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------
State: WAIT_PRAA
----------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- (re-authentication based on PRAR-PRAA exchange initiated by PAA)
Rx:PRAA None(); OPEN
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------
State: WAIT_PAUA
----------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - (PAUA processing) - - - - - - - - - -
Rx:PAUA RtxTimerStop(); OPEN
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------
State: SESS_TERM
----------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - -(Session termination initiated by PaC) - - - - -
Rx:PTA Disconnect(); CLOSED
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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7. PAA State Machine
7.1 Interface between PAA and EAP Authenticator
The interface between a PAA and an EAP authenticator provides a
mechanism to deliver EAP messages for the EAP authenticator as well
as a mechanism to notify the EAP authenticator of PAA events and to
receive notification of EAP authenticator events. These message
delivery and event notification mechanisms occur only within context
of their associated states or exit actions.
7.1.1 EAP Restart Notification from PAA to EAP Authenticator
An EAP authenticator state machine defined in
[I-D.ietf-eap-statemachine] has an initialization procedure before
sending the first EAP request. To initialize the EAP state machine,
the PAA state machine defines an event notification mechanism to send
an EAP (re)start event to the EAP peer. The event notification is
done via EAP_Restart() procedure in the initialization action of the
PAA state machine.
7.1.2 Delivering EAP Responses from PAA to EAP Authenticator
TxEAP() procedure in the PAA state machine serves as the mechanism to
deliver EAP-Responses contained in PANA-Auth-Answer messages to the
EAP authenticator. This procedure is enabled only after an EAP
restart event is notified to the EAP authenticator. In the case
where the EAP authenticator follows the EAP authenticator state
machines defined in [I-D.ietf-eap-statemachine], TxEAP() procedure
sets eapResp variable of the EAP authenticator state machine and puts
the EAP response in eapRespData variable of the EAP authenticator
state machine.
7.1.3 Delivering EAP Messages from EAP Authenticator to PAA
An EAP request is delivered from the EAP authenticator to the PaC via
EAP_REQUEST event variable. The event variable is set when the EAP
authenticator passes the EAP request to its lower-layer. In the case
where the EAP authenticator follows the EAP authenticator state
machines defined in [I-D.ietf-eap-statemachine], EAP_REQUEST event
variable refers to eapReq variable of the EAP authenticator state
machine and the EAP request is contained in eapReqData variable of
the EAP authenticator state machine.
7.1.4 EAP Authentication Result Notification from EAP Authenticator to
PAA
In order for the EAP authenticator to notify the PAA of the EAP
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authentication result, EAP_SUCCESS, EAP_FAILURE and EAP_TIMEOUT event
variables are defined. In the case where the EAP authenticator
follows the EAP authenticator state machines defined in
[I-D.ietf-eap-statemachine], EAP_SUCCESS, EAP_FAILURE and EAP_TIMEOUT
event variables refer to eapSuccess, eapFail and eapTimeout variables
of the EAP authenticator state machine, respectively. In this case,
if EAP_SUCCESS event variable is set to TRUE, an EAP-Success message
is contained in eapReqData variable of the EAP authenticator state
machine, and additionally, eapKeyAvailable variable is set to TRUE
and eapKeyData variable contains a AAA-Key if the AAA-Key is
generated as a result of successful authentication by the EAP
authentication method in use. Similarly, if EAP_FAILURE event
variable is set to TRUE, an EAP-Failure message is contained in
eapReqData variable of the EAP authenticator state machine. The PAA
uses EAP_SUCCESS, EAP_FAILURE and EAP_TIMEOUT event variables as a
trigger to send a PBR or a PFER message to the PaC.
7.2 Variables
USE_COOKIE
This variable indicates whether the PAA uses Cookie.
PIGGYBACK
This variable indicates whether the PAA is able to piggyback an
EAP-Request in PANA-Start-Request.
SEPARATE
This variable indicates whether the PAA provides NAP/ISP separate
authentication.
1ST_EAP
This variable indicates whether the 1st EAP authentication is
success, failure or yet completed.
MOBILITY
This variable indicates whether the mobility handling feature
described in Section 4.9 of [I-D.ietf-pana-pana] is supported.
PSA.SESSION_ID
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This variable contains the Session-Id AVP value in the
PANA-Start-Answer message in process.
CARRY_LIFETIME
This variable indicates whether a Session-Lifetime AVP is carried
in PANA-Bind-Request message.
PROTECTION_CAP
This variable indicates whether a Protection-Capability AVP is
carried in PANA-Bind-Request message.
CARRY_EP_DEVICE_ID
This variable indicates whether an EP-Device-Id AVP is carried in
PANA-Bind-Request message.
CARRY_NAP_INFO
This variable indicates whether a NAP-Information AVP is carried
in PANA-Start-Request message.
CARRY_ISP_INFO
This variable indicates whether an ISP-Information AVP is carried
in PANA-Start-Request message.
NAP_AUTH
This variable indicates whether a NAP authentication is being
performed or not.
CARRY_PPAC
This variable indicates whether a Post-PANA-Address-Configuration
AVP is carried in PANA-Start-Request message.
PAC_FOUND
This event variable is set to TRUE when presence of a new PaC is
informed by EP.
FAST_REAUTH
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This event variable is set to TRUE when initiation of
re-authentication based on PRAR-PRAA exchange is triggered.
TERMINATE
This event variable is set to TRUE when initiation of PANA session
termination is triggered.
EAP_SUCCESS
This event variable is set to TRUE when EAP conversation completes
with success. This event accompanies an EAP- Success message
passed from the EAP authenticator.
EAP_FAILURE
This event variable is set to TRUE when EAP conversation completes
with failure. This event accompanies an EAP- Failure message
passed from the EAP authenticator.
EAP_REQUEST
This event variable is set to TRUE when the EAP authenticator
delivers an EAP Request to the PAA. This event accompanies an
EAP-Request message received from the EAP authenticator.
EAP_TIMEOUT
This event variable is set to TRUE when EAP conversation times out
without generating an EAP-Success or an EAP-Failure message. This
event does not accompany any EAP message.
7.3 Procedures
boolean retrieve_pana_sa(Session-Id)
This procedure returns TRUE when a PANA SA for the PANA Session
corresponds to the specified Session-Id has been retrieved,
otherwise returns FALSE.
boolean new_key_available()
A procedure to check whether the PANA session has a new
PANA_MAC_KEY. If the state machine already have a PANA_MAC_KEY,
it returns FALSE. If the state machine does not have a
PANA_MAC_KEY, it tries to retrieve a AAA-Key from the EAP entity.
If a AAA-Key has been retrieved, it computes a PANA_MAC_KEY from
the AAA-Key and returns TRUE. Otherwise, it returns FALSE.
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7.4 PAA State Transition Table
------------------------------
State: OFFLINE (Initial State)
------------------------------
Initialization Action:
USE_COOKIE=Set|Unset;
PIGGYBACK=Set|Unset;
SEPARATE=Set|Unset;
if (PIGGYBACK==Set)
SEPARATE=Unset;
MOBILITY=Set|Unset;
1ST_EAP=Unset;
ABORT_ON_1ST_EAP_FAILURE=Set|Unset;
PROTECTION_CAP=Set|Unset;
CARRY_LIFETIME=Set|Unset;
CARRY_EP_DEVICE_ID=Set|Unset;
CARRY_NAP_INFO=Set|Unset;
CARRY_ISP_INFO=Set|Unset;
CARRY_PPAC=Set|Unset;
NAP_AUTH=Unset;
RTX_COUNTER=0;
RtxTimerStop();
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - (Stateful discovery)- - - - - - - - -
(Rx:PDI || EAP_Restart(); WAIT_EAP_MSG_
PAC_FOUND) && IN_DISC
USE_COOKIE==Unset &&
PIGGYBACK==Set
(Rx:PDI || if (SEPARATE==Set) STATEFUL_DISC
PAC_FOUND) && PSR.S_flag=1;
USE_COOKIE==Unset && if (CARRY_NAP_INFO==Set)
PIGGYBACK==Unset PSR.insert_avp
("NAP-Information");
if (CARRY_ISP_INFO==Set)
PSR.insert_avp
("ISP-Information");
if (CARRY_PPAC==Set)
PSR.insert_avp
("Post-PANA-Address-
Configuration");
Tx:PSR();
RtxTimerStart();
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - (Stateless discovery) - - - - - - - -
(Rx:PDI || if (SEPARATE==Set) OFFLINE
PAC_FOUND) && PSR.S_flag=1;
USE_COOKIE==Set PSR.insert_avp
("Cookie");
if (CARRY_NAP_INFO==Set)
PSR.insert_avp
("NAP-Information");
if (CARRY_ISP_INFO==Set)
PSR.insert_avp
("ISP-Information");
if (CARRY_PPAC==Set)
PSR.insert_avp
("Post-PANA-Address-
Configuration");
Tx:PSR();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - (PSA processing without mobility support) - - - -
Rx:PSA && if (SEPARATE==Set && WAIT_EAP_MSG
USE_COOKIE==Set && PSA.S_flag==0)
(!PSA.exist_avp SEPARATE=Unset;
("Session-Id") || EAP_Restart();
!PSA.exit_avp
("Nonce") ||
MOBILITY==Unset ||
(MOBILITY==Set &&
!retrieve_pana_sa
(PSA.SESSION_ID)))
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - (PSA processing with mobility support)- - - - -
Rx:PSA && PBR.insert_avp("MAC"); WAIT_SUCC_PBA
USE_COOKIE==Set && PBR.insert_avp("Nonce");
PSA.exist_avp PBR.insert_avp("Key-Id");
("Session-Id") && if (CARRY_EP_DEVICE_ID
PSA.exist_avp ==Set)
("Nonce") && PBR.insert_avp
MOBILITY==Set && ("EP-Device-Id");
retrieve_pana_sa if (PROTECTION_CAP==Set)
(PSA.SESSION_ID) PBR.insert_avp
("Protection-Cap.");
PBR.insert_avp("MAC");
Tx:PBR();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
---------------------------
State: WAIT_EAP_MSG_IN_DISC
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---------------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - (Send PSR with EAP-Request) - - - - - - -
EAP_REQUEST PSR.insert_avp STATEFUL_DISC
("EAP-Payload");
if (CARRY_NAP_INFO==Set)
PSR.insert_avp
("NAP-Information");
if (CARRY_ISP_INFO==Set)
PSR.insert_avp
("ISP-Information");
if (CARRY_PPAC==Set)
PSR.insert_avp
("Post-PANA-Address-
Configuration");
Tx:PSR();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--------------------
State: STATEFUL_DISC
--------------------
Exit Condition Action Next-State
------------------------+--------------------------+------------
- - - - - - - - - - - - - (Stateful discovery)- - - - - - - - -
Rx:PSA if (SEPARATE==Set && WAIT_PAN
PSA.S_flag==0)
SEPARATE=Unset;
if (SEPARATE==Set) {
PAR.S_flag=1;
NAP_AUTH=Set|Unset;
if (NAP_AUTH==Set)
PAR.N_flag=1;
}
Tx:PAR();
EAP_TIMEOUT Tx:PER(); CLOSED
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-------------------
State: WAIT_EAP_MSG
-------------------
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Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - -(Receiving EAP-Request)- - - - - - - - -
EAP_REQUEST if (key_available()) WAIT_PAN
PAR.insert_avp("MAC");
if (SEPARATE==Set) {
PAR.S_flag=1;
if (NAP_AUTH==Set)
PAR.N_flag=1;
}
Tx:PAR();
EAP_TIMEOUT Tx:PER(); CLOSED
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - -(Receiving EAP-Success/Failure for 1st EAP)- - - -
EAP_FAILURE && 1ST_EAP=Failure WAIT_FAIL_PBA
1ST_EAP==Unset && PBR.insert_avp
SEPARATE==Unset ("EAP-Payload");
if (key_available())
PBR.insert_avp("MAC");
Tx:PBR();
RtxTimerStart();
EAP_SUCCESS && 1ST_EAP=Success WAIT_SUCC_PBA
1ST_EAP==Unset && PBR.insert_avp
SEPARATE==Unset && ("EAP-Payload");
Authorize() if (CARRY_EP_DEVICE_ID
==Set)
PBR.insert_avp
("EP-Device-Id");
if (CARRY_LIFETIME==Set)
PBR.insert_avp
("Session-Lifetime");
if (PROTECTION_CAP==Set)
PBR.insert_avp
("Protection-Cap.");
if (new_key_available())
PBR.insert_avp
("Key-Id");
if (key_available())
PBR.insert_avp("MAC");
Tx:PBR();
RtxTimerStart();
EAP_SUCCESS && 1ST_EAP=Success WAIT_FAIL_PBA
1ST_EAP==Unset && PBR.insert_avp
SEPARATE==Unset && ("EAP-Payload");
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!Authorize() if (new_key_available())
PBR.insert_avp
("Key-Id");
if (key_available())
PBR.insert_avp("MAC");
Tx:PBR();
RtxTimerStart();
EAP_FAILURE && 1ST_EAP=Failure WAIT_PFEA
1ST_EAP==Unset && PBR.insert_avp
SEPARATE==Set && ("EAP-Payload");
ABORT_ON_1ST_EAP_FAILURE if (key_available())
==Unset PFER.insert_avp("MAC");
PFER.S_flag=1;
if (NAP_AUTH)
PFER.N_flag=1;
Tx:PFER();
RtxTimerStart();
EAP_FAILURE && 1ST_EAP=Failure WAIT_FAIL_PFEA
1ST_EAP==Unset && PFER.insert_avp
SEPARATE==Set && ("EAP-Payload");
ABORT_ON_1ST_EAP_FAILURE if (key_available())
==Set PFER.insert_avp("MAC");
PFER.S_flag=0;
Tx:PFER();
RtxTimerStart();
EAP_SUCCESS && 1ST_EAP=Success WAIT_PFEA
1ST_EAP==Unset && PFER.insert_avp
SEPARATE==Set ("EAP-Payload");
if (new_key_available())
PFER.insert_avp
("Key-Id");
if (key_available())
PFER.insert_avp("MAC");
PFER.S_flag=1;
if (NAP_AUTH)
PFER.N_flag=1;
Tx:PFER();
RtxTimerStart();
EAP_TIMEOUT && 1ST_EAP=Failure FAIT_FAIL_PBA
1ST_EAP==Unset && if (key_available())
SEPARATE==Unset PBR.insert_avp("MAC");
Tx:PBR();
RtxTimerStart();
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EAP_TIMEOUT && 1ST_EAP=Failure WAIT_PFEA
1ST_EAP==Unset && if (key_available())
SEPARATE==Set && PFER.insert_avp("MAC");
ABORT_ON_1ST_EAP_FAILURE PFER.S_flag=1;
==Unset if (NAP_AUTH)
PFER.N_flag=1;
Tx:PFER();
RtxTimerStart();
EAP_TIMEOUT && 1ST_EAP=Failure WAIT_FAIL_PFEA
1ST_EAP==Unset && if (key_available())
SEPARATE==Set && PFER.insert_avp("MAC");
ABORT_ON_1ST_EAP_FAILURE SEPARATE=Unset;
==Set PFER.S_flag=0;
Tx:PFER();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - -(Receiving EAP-Success/Failure for 2nd EAP)- - - -
EAP_FAILURE && PBR.insert_avp WAIT_FAIL_PBA
1ST_EAP==Failure ("EAP-Payload");
if (key_available())
PBR.insert_avp("MAC");
if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
EAP_SUCCESS && PBR.insert_avp WAIT_SUCC_PBA
1ST_EAP==Success && ("EAP-Payload");
Authorize() if (CARRY_EP_DEVICE_ID
==Set)
PBR.insert_avp
("EP-Device-Id");
if (PROTECTION_CAP==Set)
PBR.insert_avp
("Protection-Cap.");
if (new_key_available())
PBR.insert_avp
("Key-Id");
if (key_available())
PBR.insert_avp("MAC");
if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
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Tx:PBR();
RtxTimerStart();
EAP_SUCCESS && PBR.insert_avp WAIT_FAIL_PBA
1ST_EAP==Success && ("EAP-Payload");
!Authorize() if (new_key_available())
PBR.insert_avp
("Key-Id");
if (key_available())
PBR.insert_avp("MAC");
if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
EAP_FAILURE && PBR.insert_avp WAIT_SUCC_PBA
1ST_EAP==Success && ("EAP-Payload");
Authorize() if (key_available())
PBR.insert_avp("MAC");
if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
EAP_FAILURE && PBR.insert_avp WAIT_FAIL_PBA
1ST_EAP==Success && ("EAP-Payload");
!Authorize() if (key_available())
PBR.insert_avp("MAC");
if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
EAP_TIMEOUT && if (key_available()) WAIT_FAIL_PBA
1ST_EAP==Failure PBR.insert_avp("MAC");
if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
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EAP_TIMEOUT && if (key_available()) WAIT_SUCC_PBA
1ST_EAP==Success && PBR.insert_avp("MAC");
Authorize() if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
EAP_TIMEOUT && if (key_available()) WAIT_FAIL_PBA
1ST_EAP==Success && PBR.insert_avp("MAC");
!Authorize() if (SEPARATE)
PBR.S_flag=1;
if (NAP_AUTH)
PBR.N_flag=1;
Tx:PBR();
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------
State: WAIT_PFEA
----------------
Event/Condition Action Next-State
------------------------+--------------------------+------------
- - - - - - - - - - - -(PFEA Processing)- - - - - - - - - - - -
Rx:PFEA && if (key_available()) WAIT_EAP_MSG
PFEA.S_flag==1 PAR.insert_avp("MAC");
if (NAP_AUTH==Set) {
NAP_AUTH=Unset;
PAR.N_flag=0;
} else {
NAP_AUTH=Set;
PAR.N_flag=1;
};
EAP_Restart();
Rx:PFEA && RtxTimerStop(); CLOSED
PFEA.S_flag==0 Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
---------------------
State: WAIT_FAIL_PFEA
---------------------
Event/Condition Action Next-State
------------------------+--------------------------+------------
- - - - - - - - - - - - - -(PFEA Processing)- - - - - - - - - -
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Rx:PFEA RtxTimerStop(); CLOSED
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--------------------
State: WAIT_SUCC_PBA
--------------------
Event/Condition Action Next-State
------------------------+--------------------------+------------
- - - - - - - - - - - - - (PBA Processing)- - - - - - - - - - -
Rx:PBA SessionTimerStart(); OPEN
Authorize();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--------------------
State: WAIT_FAIL_PBA
--------------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - - (PBA Processing)- - - - - - - - - -
Rx:PBA RtxTimerStop(); CLOSED
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-----------
State: OPEN
-----------
Event/Condition Action Next-State
------------------------+--------------------------+------------
- - - - - - - - - - (EAP-based re-authentication) - - - - - - -
EAP_REAUTH || if (key_available()) WAIT_EAP_MSG
(Rx:PDI && PAR.insert_avp("MAC");
PDI.exist_avp EAP_Restart();
("Session-Id")) 1ST_EAP=Unset;
NAP_AUTH=Set|Unset;
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- (re-authentication based on PRAR-PRAA exchange initiated by PAA)
FAST_REAUTH Tx:PRAR(); WAIT_PRAA
RtxTimerStart();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - (Session termination initated from PAA) - - - -
TERMINATE if (key_available()) SESS_TERM
PTR.insert_avp("MAC");
Tx:PTR();
RtxTimerStart();
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - (Session termination initated from PaC) - - - -
Rx:PTR if (key_available()) CLOSED
PTA.insert_avp("MAC");
Tx:PTA();
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - -(Address update) - - - - - - - - - - -
Rx:PAUR && Tx:PAUA(); OPEN
Authorize()
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------
State: WAIT_PRAA
----------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - (PRAA processing) - - - - - - - - - -
Rx:PRAA RtxTimerStop(); OPEN
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
---------------
State: WAIT_PAN
---------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - (Pass EAP Resposne to the EAP authenticator)- - - -
Rx:PAN TxEAP(); WAIT_EAP_MSG
EAP_TIMEOUT Tx:PER(); CLOSED
RtxTimerStop();
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------------
State: SESS_TERM
----------------
Exit Condition Exit Action Exist State
------------------------+--------------------------+------------
- - - - - - - - - - - - - -(PTA processing) - - - - - - - - - -
Rx:PTA RtxTimerStop(); CLOSED
Disconnect();
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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8. Implementation Considerations
8.1 Interface exposed by PANA to the Host System
It is recommended that a generic interface be provided by the
implementation to enable the host system to manage the PANA protocol
stack. It is conceivable that the PANA protocol stack resides as
part of the operating system network services. Therefore, it is
conceded that this interface will inherently have a certain level of
system dependency. However, common procedures such as startup,
shutdown, re-authenticate signals and provisions for extracting
keying material should be provided by all implementations. Host
operating systems may require finer control on when re-authentication
can occur. Also, access to keying material is especially critical
when PANA is used for bootstrapping external protocols such as IPsec.
Additional bootstrapping interface may also need to be defined to
accommodate such functionality.
8.2 PAA Interface to EP
Since the PANA protocol stack has a peer relationship with the EP and
perhaps other network services in a host system, it is recommended
that a standardized interface be defined to accommodate their
integration. If the PAA and EP are not co-located, this interface
may come in the form of an SNMP conversations between PANA and EP as
defined in [I-D.ietf-pana-snmp]. A standard mechanism such as SNMP
minimizes complications associated with proprietary PAA-to-EP
interfaces.
If the PAA and the EP are co-located, it is recommended that a
PAA-to-EP API be defined. The functionality and definitions of this
API should use Section 4.4 of the [I-D.ietf-pana-requirements] and
[I-D.ietf-pana-snmp] as a guide. It is conceded that such an API may
have a certain level of system dependency. However, certain
programming models allow for exposing an API in a relatively system
independent way but at the cost of performance. Models such as COM/
DCOM, CORBA, SOAP or RPC messaging systems may be used to decrease
system dependency. These models may also provide support for non
co-located invocations of the API and may even provide some degree of
inherent security. However, such usage is recommended only if there
is high level of certainty that all entities are within the same
administratively secure domain. It is left to the implementation to
decide which programming model the API will utilize. Such decisions
are dictated by software engineering practices as well as the
implementation environment and are beyond the scope of this document.
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8.3 Multicast Traffic
In general, binding a UDP socket to a multicast address and/or port
is system dependent. In most systems, a socket can be bounded to any
address and a specific port. This allows the socket to receive all
packets destined for the local host (on all it's local addresses) for
that port. If the host subscribes to a multicast addresses then this
socket will also receive multicast traffic as well. In some systems,
this would also result in the socket receiving all multicast traffic
even though it has subscribed to only one multicast address. This is
because most physical interfaces has either multicast traffic enabled
or disabled and does not provide specific address filtering.
Normally, it is not possible to filter out specific traffic on a
socket from the user level. Most environments provides lower layer
filtering that allows the use of only one socket to receive both
unicast and specific multicast address. However it might introduce
portability problems.
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9. Security Considerations
This document's intent is to describe the PANA state machines fully.
To this end, any security concerns with this document are likely a
reflection of security concerns with PANA itself.
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10. Acknowledgments
This work was started from state machines originally made by Dan
Forsberg.
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11. References
11.1 Normative References
[I-D.ietf-pana-pana]
Forsberg, D., Ohba, Y., Patil, B., Tschofenig, H. and A.
Yegin, "Protocol for Carrying Authentication for Network
Access (PANA)", draft-ietf-pana-pana-04 (work in
progress), May 2004.
[I-D.ietf-eap-statemachine]
Vollbrecht, J., Eronen, P., Petroni, N. and Y. Ohba,
"State Machines for Extensible Authentication Protocol
(EAP) Peer and Authenticator",
draft-ietf-eap-statemachine-03 (work in progress), March
2004.
11.2 Informative References
[I-D.ietf-pana-requirements]
Yegin, A. and Y. Ohba, "Protocol for Carrying
Authentication for Network Access (PANA)Requirements",
draft-ietf-pana-requirements-08 (work in progress), June
2004.
[I-D.ietf-pana-snmp]
Mghazli, Y., Ohba, Y. and J. Bournelle, "SNMP usage for
PAA-2-EP interface", draft-ietf-pana-snmp-00 (work in
progress), April 2004.
Authors' Addresses
Yoshihiro Ohba
Toshiba America Research, Inc.
1 Telcordia Drive
Piscataway, NJ 08854
USA
Phone: +1 732 699 5305
EMail: yohba@tari.toshiba.com
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Victor Fajardo
Consultant of Toshiba America Research, Inc.
1 Telcordia Drive
Piscataway, NJ 08854
USA
Phone: +1 732 699 5368
EMail: vfajardo@msbx.net
Rafa Marin Lopez
University of Murcia
30071 Murcia
Spain
EMail: rafa@dif.um.es
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Acknowledgment
Funding for the RFC Editor function is currently provided by the
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Ohba, et al. Expires January 9, 2005 [Page 47]