PANA Working Group D. Forsberg
Internet-Draft Nokia
Expires: April 20, 2005 Y. Ohba (Ed.)
Toshiba
B. Patil
Nokia
H. Tschofenig
Siemens
A. Yegin
Samsung
October 20, 2004
Protocol for Carrying Authentication for Network Access (PANA)
draft-ietf-pana-pana-06
Status of this Memo
By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed,
and any of which I become aware will be disclosed, in accordance with
RFC 3668.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 20, 2005.
Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
Extensible Authentication Protocol (EAP) defines a number of
authentication schemes. Network access authentication requires a
Forsberg, et al. Expires April 20, 2005 [Page 1]
Internet-Draft PANA October 2004
host to authenticate itself before being authorized for sending and
receiving packets. The Protocol for Carrying Authentication for
Network Access (PANA) is defined in this document. PANA is a
link-layer agnostic carrier for EAP. PANA specifies the
client-to-network access authentication within the scope of an
overall secure network access framework.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Specification of Requirements . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Protocol Overview . . . . . . . . . . . . . . . . . . . . . 8
4. Protocol Details . . . . . . . . . . . . . . . . . . . . . . 10
4.1 Discovery and Handshake Phase . . . . . . . . . . . . . . 10
4.2 Authentication Phase . . . . . . . . . . . . . . . . . . . 13
4.3 Authorization Phase . . . . . . . . . . . . . . . . . . . 15
4.4 Re-authentication Phase . . . . . . . . . . . . . . . . . 15
4.5 Termination Phase . . . . . . . . . . . . . . . . . . . . 17
5. Protocol Design Details and Processing Rules . . . . . . . . 19
5.1 Payload Encoding . . . . . . . . . . . . . . . . . . . . . 19
5.2 Transport Layer . . . . . . . . . . . . . . . . . . . . . 20
5.2.1 Fragmentation . . . . . . . . . . . . . . . . . . . . 20
5.3 Sequence Number and Retransmission . . . . . . . . . . . . 20
5.4 Message Authentication Code . . . . . . . . . . . . . . . 21
5.5 Message Validity Check . . . . . . . . . . . . . . . . . . 21
5.6 PANA Security Association . . . . . . . . . . . . . . . . 23
5.7 Error Handling . . . . . . . . . . . . . . . . . . . . . . 25
5.8 Device ID Choice . . . . . . . . . . . . . . . . . . . . . 25
5.9 Updating PaC' Address . . . . . . . . . . . . . . . . . . 26
5.10 Session Lifetime . . . . . . . . . . . . . . . . . . . . 26
5.11 Network Selection . . . . . . . . . . . . . . . . . . . 27
5.12 Separate NAP and ISP Authentication . . . . . . . . . . 27
5.12.1 Negotiating Separate NAP and ISP Authentication . . 28
5.12.2 Execution of Separate NAP and ISP Authentication . . 28
5.12.3 AAA-Key Calculation . . . . . . . . . . . . . . . . 29
5.12.4 Re-authentication . . . . . . . . . . . . . . . . . 30
5.12.5 Example Sequence . . . . . . . . . . . . . . . . . . 30
6. Security and Mobility . . . . . . . . . . . . . . . . . . . 32
6.1 PANA Security Association Establishment . . . . . . . . . 32
6.2 Mobility . . . . . . . . . . . . . . . . . . . . . . . . . 32
7. PANA Headers and Formats . . . . . . . . . . . . . . . . . . 35
7.1 IP and UDP Headers . . . . . . . . . . . . . . . . . . . . 35
7.2 PANA Header . . . . . . . . . . . . . . . . . . . . . . . 35
7.3 AVP Header . . . . . . . . . . . . . . . . . . . . . . . . 37
8. PANA Messages, Message Specifications and AVPs . . . . . . . 40
8.1 PANA Messages . . . . . . . . . . . . . . . . . . . . . . 40
8.2 Message Specifications . . . . . . . . . . . . . . . . . . 40
Forsberg, et al. Expires April 20, 2005 [Page 2]
Internet-Draft PANA October 2004
8.2.1 PANA-PAA-Discover (PDI) . . . . . . . . . . . . . . . 41
8.2.2 PANA-Start-Request (PSR) . . . . . . . . . . . . . . . 41
8.2.3 PANA-Start-Answer (PSA) . . . . . . . . . . . . . . . 41
8.2.4 PANA-Auth-Request (PAR) . . . . . . . . . . . . . . . 41
8.2.5 PANA-Auth-Answer (PAN) . . . . . . . . . . . . . . . . 42
8.2.6 PANA-Reauth-Request (PRAR) . . . . . . . . . . . . . . 42
8.2.7 PANA-Reauth-Answer (PRAA) . . . . . . . . . . . . . . 42
8.2.8 PANA-Bind-Request (PBR) . . . . . . . . . . . . . . . 42
8.2.9 PANA-Bind-Answer (PBA) . . . . . . . . . . . . . . . . 43
8.2.10 PANA-Ping-Request (PPR) . . . . . . . . . . . . . . 43
8.2.11 PANA-Ping-Answer (PPA) . . . . . . . . . . . . . . . 43
8.2.12 PANA-Termination-Request (PTR) . . . . . . . . . . . 43
8.2.13 PANA-Termination-Answer (PTA) . . . . . . . . . . . 44
8.2.14 PANA-Error-Request (PER) . . . . . . . . . . . . . . 44
8.2.15 PANA-Error-Answer (PEA) . . . . . . . . . . . . . . 44
8.2.16 PANA-FirstAuth-End-Request (PFER) . . . . . . . . . 44
8.2.17 PANA-FirstAuth-End-Answer (PFEA) . . . . . . . . . . 45
8.2.18 PANA-Update-Request (PUR) . . . . . . . . . . . . . 45
8.2.19 PANA-Update-Answer (PUA) . . . . . . . . . . . . . . 45
8.3 AVPs in PANA . . . . . . . . . . . . . . . . . . . . . . . 45
8.3.1 MAC AVP . . . . . . . . . . . . . . . . . . . . . . . 48
8.3.2 Device-Id AVP . . . . . . . . . . . . . . . . . . . . 49
8.3.3 Session-Id AVP . . . . . . . . . . . . . . . . . . . . 49
8.3.4 Cookie AVP . . . . . . . . . . . . . . . . . . . . . . 49
8.3.5 Protection-Capability AVP . . . . . . . . . . . . . . 49
8.3.6 Termination-Cause AVP . . . . . . . . . . . . . . . . 49
8.3.7 Result-Code AVP . . . . . . . . . . . . . . . . . . . 50
8.3.8 EAP-Payload AVP . . . . . . . . . . . . . . . . . . . 54
8.3.9 Session-Lifetime AVP . . . . . . . . . . . . . . . . . 54
8.3.10 Failed-AVP AVP . . . . . . . . . . . . . . . . . . . 54
8.3.11 NAP-Information AVP . . . . . . . . . . . . . . . . 54
8.3.12 ISP-Information AVP . . . . . . . . . . . . . . . . 54
8.3.13 Provider-Identifier AVP . . . . . . . . . . . . . . 54
8.3.14 Provider-Name AVP . . . . . . . . . . . . . . . . . 55
8.3.15 Key-Id AVP . . . . . . . . . . . . . . . . . . . . . 55
8.3.16 Post-PANA-Address-Configuration (PPAC) AVP . . . . . 55
8.3.17 Nonce AVP . . . . . . . . . . . . . . . . . . . . . 56
8.3.18 IP-Address AVP . . . . . . . . . . . . . . . . . . . 56
9. PANA Protocol Message Retransmissions . . . . . . . . . . . 57
9.1 Transmission and Retransmission Parameters . . . . . . . . 58
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 60
10.1 PANA UDP Port Number . . . . . . . . . . . . . . . . . . 60
10.2 PANA Multicast Address . . . . . . . . . . . . . . . . . 60
10.3 PANA Header . . . . . . . . . . . . . . . . . . . . . . 60
10.3.1 Message Type . . . . . . . . . . . . . . . . . . . . 60
10.3.2 Flags . . . . . . . . . . . . . . . . . . . . . . . 61
10.4 AVP Header . . . . . . . . . . . . . . . . . . . . . . . 61
10.4.1 AVP Code . . . . . . . . . . . . . . . . . . . . . . 61
Forsberg, et al. Expires April 20, 2005 [Page 3]
Internet-Draft PANA October 2004
10.4.2 Flags . . . . . . . . . . . . . . . . . . . . . . . 62
10.5 AVP Values . . . . . . . . . . . . . . . . . . . . . . . 62
10.5.1 Algorithm Values of MAC AVP . . . . . . . . . . . . 62
10.5.2 Protection-Capability AVP Values . . . . . . . . . . 62
10.5.3 Termination-Cause AVP Values . . . . . . . . . . . . 62
10.5.4 Result-Code AVP Values . . . . . . . . . . . . . . . 62
10.5.5 Post-PANA-Address-Configuration AVP Values . . . . . 63
11. Security Considerations . . . . . . . . . . . . . . . . . . 64
11.1 General Security Measures . . . . . . . . . . . . . . . 64
11.2 Discovery . . . . . . . . . . . . . . . . . . . . . . . 65
11.3 EAP Methods . . . . . . . . . . . . . . . . . . . . . . 66
11.4 Separate NAP and ISP Authentication . . . . . . . . . . 66
11.5 Cryptographic Keys . . . . . . . . . . . . . . . . . . . 66
11.6 Per-packet Ciphering . . . . . . . . . . . . . . . . . . 67
11.7 PAA-to-EP Communication . . . . . . . . . . . . . . . . 67
11.8 Livenes Test . . . . . . . . . . . . . . . . . . . . . . 68
11.9 Mobility Optimization . . . . . . . . . . . . . . . . . 68
11.10 Updating PaC's IP Address . . . . . . . . . . . . . . . 68
11.11 Early Termination of a Session . . . . . . . . . . . . . 69
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 70
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 71
13.1 Normative References . . . . . . . . . . . . . . . . . . . 71
13.2 Informative References . . . . . . . . . . . . . . . . . . 72
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 73
Intellectual Property and Copyright Statements . . . . . . . 75
Forsberg, et al. Expires April 20, 2005 [Page 4]
Internet-Draft PANA October 2004
1. Introduction
Network access authentication has traditionally been a layer 2
function. This document specifies a protocol that enables EAP to be
transported above the IP layer. As a result, network access
authentication can be made a function of the network layer thereby
achieving link-layer independence for the process of authenticating a
client seeking access to a network. At the present time, there are
no standardized solutions for authenticating a host for network
access at the network layer. The problem statement for which the
PANA protocol is a solution can be found in Appendix A of
[I-D.ietf-pana-requirements].
PANA relies on EAP for the actual authentication of a client. It
does not define any new authentication protocols or schemes. It
enables EAP messages to be carried between the client and the
network. The actual choice of a specific EAP method to be run over
PANA is dependent on the underlying access network technology. The
key factor in the choice of the EAP method is the determination of
whether the lower layer (link/physical) provides security for the
PANA messages.
A secure network access authentication framework goes beyond just
authenticating the client to the network. Other aspects such as
address configuration, data traffic security, access control filters
and separation of the enforcement point from the protocol end-point
are documented in [I-D.ietf-pana-framework] and [I-D.ietf-pana-snmp].
This document specifies the client-network interaction and the
messages defined for this purpose.
1.1 Specification of Requirements
In this document, several words are used to signify the requirements
of the specification. These words are often capitalized. The key
words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
"SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document
are to be interpreted as described in [RFC2119].
Forsberg, et al. Expires April 20, 2005 [Page 5]
Internet-Draft PANA October 2004
2. Terminology
PANA Client (PaC):
The client side of the protocol that resides in the host device.
It is responsible for providing the credentials in order to prove
its identity for network access authorization.
PANA Authentication Agent (PAA):
The protocol entity in the access network whose responsibility is
to verify the credentials provided by a PANA client (PaC) and
authorize network access to the device associated with the client
and identified by a Device Identifier (DI). Note the
authentication and authorization procedure can, according to the
EAP model, be also offloaded to the backend AAA infrastructure.
PANA Session:
A PANA session begins with the handshake between the PANA Client
(PaC) and the PANA Authentication Agent (PAA), and terminates as a
result of an authentication failure, a timeout, or an explicit
termination message. A fixed session identifier is maintained
throughout a session. A session cannot be shared across multiple
network interfaces.
Session Identifier:
This identifier is used to uniquely identify a PANA session on the
PAA and PaC. It includes an identifier of the PAA, therefore it
cannot be shared across multiple PAAs. It is included in PANA
messages to bind the message to a specific PANA session. This
bidirectional identifier is allocated by the PAA following the
handshake and freed when the session terminates.
PANA Security Association (PANA SA):
A PANA security association is a relationship between the PaC and
PAA, formed by the sharing of cryptographic keying material and
associated context. Security associations are duplex. That is,
one security association is needed to protect the bidirectional
traffic between the PaC and the PAA.
Device Identifier (DI):
Forsberg, et al. Expires April 20, 2005 [Page 6]
Internet-Draft PANA October 2004
The identifier used by the network as a handle to control and
police the network access of a client. Depending on the access
technology, this identifier may contain an address that is carried
in protocol headers (e.g., IP or link-layer address), or a locally
significant identifier that is made available by the local
protocol stack (e.g., circuit id, PPP interface id) of a connected
device.
Enforcement Point (EP):
A node on the access network where per-packet enforcement policies
(i.e., filters) are applied on the inbound and outbound traffic of
client devices. Information such as the DI and (optionally)
cryptographic keys are provided by the PAA per client for
generating filters on the EP.
Network Access Provider (NAP):
A service provider that provides physical and link-layer
connectivity to an access network it manages.
AAA-Key:
A key derived by the EAP peer and EAP server and transported to
the authenticator [I-D.ietf-eap-keying].
Forsberg, et al. Expires April 20, 2005 [Page 7]
Internet-Draft PANA October 2004
3. Protocol Overview
The PANA protocol is run between a client (PaC) and a server (PAA) in
order to perform authentication and authorization for the network
access service.
The protocol messaging consists of a series of request and responses,
some of which may be initiated by either ends. Each message can
carry zero or more AVPs as payload. The main payload of PANA is EAP
which performs authentication. PANA helps PaC and PAA establish an
EAP session.
PANA is a UDP-based protocol. It has its own retransmission
mechanism to reliably deliver messages.
PANA messages are sent between a PaC and PAA as part of a PANA
session. A PANA session consists of distinct phases:
o Discovery and handshake phase: This is the phase that initiates a
new PANA session. The PaC discovers the PAA(s) by either
explicitly soliciting advertisements for them or receiving
unsolicited advertisements. The PaC's answer sent in response to
an advertisement starts a new session.
o Authentication phase: Immediately following the handshake phase is
the EAP execution between the PAA and PaC. The EAP payloads
(which carry an EAP method inside) is what is used for
authentication. Authentication phase may involve execution of two
EAP sessions back-to-back, one for the NAP and one for the ISP.
o Authorization phase: Following a successful PANA authentication
phase, the PaC gains access to the network and can send and
receive IP data traffic through EP. During this phase, the PaC
and PAA may optionally ping each other to test liveness of the
PANA session on each end.
o Re-authentication phase: Following an authorization phase, the PAA
must initiate re-authentication before the PANA session lifetime
expires. Again EAP is carried by PANA to perform authentication.
This phase may be optionally triggered by both the PaC and the PAA
without any respect to the session lifetime. The session moves to
this phase from authorized phase, and returns back there upon
successful re-authentication.
o Termination phase: The PaC or PAA may choose to discontinue the
access service at any time. An explicit disconnect message can be
sent by either end. If either the PaC or the PAA disconnects
without engaging in termination messaging, it is expected that
Forsberg, et al. Expires April 20, 2005 [Page 8]
Internet-Draft PANA October 2004
either the expiration of a finite session lifetime or failed
liveness tests would do the job.
PaC PAA Message[AVPs]
-----------------------------------------------------
// Discovery and handshake phase
-----> PANA-PAA-Discover
<----- PANA-Start-Request
-----> PANA-Start-Answer
// Authentication phase
<----- PANA-Auth-Request /* EAP Request */
-----> PANA-Auth-Answer
-----> PANA-Auth-Request /* EAP Response */
<----- PANA-Auth-Answer
<----- PANA-Bind-Request /* EAP Success */
-----> PANA-Bind-Answer
// Authorization phase (IP data traffic allowed)
<----- PANA-Ping-Request
-----> PANA-Ping-Answer
// Termination phase
-----> PANA-Termination-Request
<----- PANA-Termination-Answer
Figure 1: Illustration of PANA Messages in a Session
Cryptographic protection of messages between the PaC and PAA is
possible as soon as EAP in conjunction with the EAP method exports a
shared key. That shared key is used to create a PANA SA. The PANA
SA helps generating per-message authentication codes that provide
integrity protection and authentication.
PANA also allows creation of a new PANA session with a new PAA out of
an existing session with another PAA. This optimization allows PaC
achieve quicker authorization without having to run EAP upon movement
(changing PAAs).
Throughout the lifetime of a session, various problems found with the
incoming messages can generate a PANA error message sent in response.
Forsberg, et al. Expires April 20, 2005 [Page 9]
Internet-Draft PANA October 2004
4. Protocol Details
The following sections explain in detail the various phases of a PANA
session.
4.1 Discovery and Handshake Phase
When a PaC attaches to a network, and knows that it has to discover a
PAA, it SHOULD send a PANA-PAA-Discover message to a well-known link
local multicast address (TBD) and UDP port (TBD). The PANA PAA
discovery assumes that the PaC and the PAA are one hop away from each
other. If the PaC knows the IP address of the PAA (based on
pre-configuration), it MAY unicast the PANA-PAA-Discover message to
that address.
When the PAA receives a PANA-PAA-Discover message from a PaC, the PAA
SHOULD unicast a PANA-Start-Request message to the PaC.
The PaC MAY also choose to start sending packets before getting
authenticated. In that case, the network may detect this and the PAA
MAY send an unsolicited PANA-Start-Request message to the PaC in
addition to filtering the unauthorized traffic. The EP is the node
that can detect such activity. The PAA-to-EP protocol MAY be used
for this purpose.
When a PaC receives a PANA-Start-Request message from a PAA, it
responds with a PANA-Start-Answer message if it wishes to enter an
authentication phase. The answer message copies the sequence number.
There can be multiple PAAs on the link and a PaC may receive multiple
PANA-Start-Request messages from those PAAs. The authentication and
authorization result does not depend on which PAA is chosen by the
PaC. By default the PaC MAY choose the PAA that sent the first
response.
A PANA-Start-Request message MAY carry a Cookie AVP that contains a
cookie. The sequence number is set to a randomly picked initial
sequence number. The cookie is used for preventing the PAA from
resource consumption DoS attacks by blind attackers. The cookie is
computed in such a way that it does not require any per-session state
maintenance on the PAA in order to verify the cookie returned in a
PANA-Start-Answer message. The exact algorithms and syntax used for
generating cookies does not affect interoperability and hence is not
specified here. An example algorithm is described below.
Cookie =
<secret-version> | HMAC_SHA1( <Device-Id of PaC> , <secret> )
Forsberg, et al. Expires April 20, 2005 [Page 10]
Internet-Draft PANA October 2004
where <secret> is a randomly generated secret known only to the PAA,
<secret-version> is an index used for choosing the secret for
generating the cookie and '|' indicates concatenation. The
secret-version should be changed frequently enough to prevent replay
attacks. The secret key is valid for a certain time frame.
When the PaC sends a PANA-Start-Answer message in response to a
PANA-Start-Request containing a Cookie AVP, the answer MUST contain a
Cookie AVP with the cookie value copied from the request.
When the PAA receives the PANA-Start-Answer message from the PaC, it
verifies the cookie. The cookie is considered as valid if the
received cookie has the expected value. If the computed cookie is
valid, the protocol enters an authentication phase. Otherwise, it
MUST silently discard the received message.
Initial EAP Request MAY be optionally carried by the
PANA-Start-Request (as opposed to by a later PANA-Auth-Request)
message in order to reduce the number of round-trips. This
optimization SHOULD NOT be used if the PAA discovery is desired to be
stateless.
A Protection-Capability AVP and a Post-PANA-Address-Configuration
(PPAC) AVP MAY be included in the PANA-Start-Request in order to
indicate required and available capabilities for the network access.
These AVPs MAY be used by the PaC for assessing the capability match
even before the authentication takes place. But these AVPs are
provided during the insecure discovery and handshake phase, there are
certain security risks involved in using the provided information.
See Section 11 for further discussion on this.
If the initial EAP Request message is carried in the
PANA-Start-Request message, an EAP Response message MUST be carried
in the PANA-Start-Answer message returned to the PAA.
In any case, PANA MUST NOT generate an EAP message on behalf of EAP
peer or EAP (pass-through) authenticator.
The PANA-Start-Request/Answer exchange is needed before entering an
authentication phase even when the PaC is pre-configured with PAAs IP
address and the PANA-PAA-Discover message is unicast.
A Nonce AVP MUST be included in PANA-Start-Request and
PANA-Start-Answer messages. The nonces are used to establish a PANA
SA.
A PANA-Start-Request message that carries a Cookie AVP is never
retransmitted. A PANA-Start-Request message that does not carry a
Forsberg, et al. Expires April 20, 2005 [Page 11]
Internet-Draft PANA October 2004
Cookie AVP is retransmitted based on timer. A PANA-Start-Answer
message that carries a Cookie AVP is retransmitted based on timer. A
PANA-Start-Answer message that does not carry a Cookie AVP is never
retransmitted based on timer.
It is possible that both the PAA and the PaC initiate the discovery
and handshake procedure at the same time, i.e., the PAA sends a
PANA-Start-Request message while the PaC sends a PANA-PAA-Discover
message. To resolve the race condition, the PAA SHOULD silently
discard the PANA-PAA-Discover message received from the PaC after it
has sent a PANA-Start-Request message with creating a state (i.e., no
Cookie AVP is included in the message) for the PaC. In this case PAA
will retransmit PANA-Start-Request based on a timer, if PaC doesn't
respond in time (message was lost for example). If the PAA had sent
a PANA-Start-Request message without creating a state for the PaC
(i.e., a Cookie AVP was included in the message), then it SHOULD
answer to the PANA-PAA-Discover message.
Figure 2 shows an example sequence for the discovery and handshake
phase when a PANA-PAA-Discover message is sent by the PaC. Figure 3
shows an example sequence for the discovery and handshake phase that
is triggered by data traffic.
PaC PAA Message(seqno)[AVPs]
------------------------------------------------------
-----> PANA-PAA-Discover(0)
<----- PANA-Start-Request(x)[Nonce, Cookie]
-----> PANA-Start-Answer(x)[Nonce, Cookie]
(continued to authentication phase)
Figure 2: Example Sequence for Discovery and Handshake Phase when
PANA-PAA-Discover is sent by PaC
PaC EP PAA Message(seqno)[AVPs]
------------------------------------------------------
---->o (Data packet arrival or L2 trigger)
------> PAA-to-EP protocol, or another mechanism
<------------ PANA-Start-Request(x)[Nonce, Cookie]
------------> PANA-Start-Answer(x)[Nonce, Cookie]
(continued to authentication phase)
Figure 3: Example Sequence for Discovery and Handshake when discovery
is triggered by data traffic
Forsberg, et al. Expires April 20, 2005 [Page 12]
Internet-Draft PANA October 2004
4.2 Authentication Phase
The main task in authentication phase is to carry EAP messages
between the PaC and the PAA. EAP Request and Response messages are
carried in PANA-Auth-Request messages. PANA-Auth-Answer messages are
simply used to acknowledge receipt of the requests. As an
optimization, a PANA-Auth-Answer message MAY include the EAP
Response. Another optimization allows optionally carrying the first
EAP Request/Response in PANA-Start-Request/Answer message as
described in Section 4.1
When an EAP Success/Failure message is sent from a PAA, the message
is carried in a PANA-Bind-Request (PBR) message. The
PANA-Bind-Request messages MUST be acknowledged with a
PANA-Bind-Answer (PBA) message. Figure 4 shows an example sequence
in an authentication phase.
PaC PAA Message(seqno)[AVPs]
--------------------------------------------------------------------
(continued from discovery and handshake phase)
<----- PANA-Auth-Request(x+1)
[Session-Id, EAP{Request}]
-----> PANA-Auth-Answer(x+1) // No piggybacking EAP-Response
[Session-Id]
-----> PANA-Auth-Request(y)
[Session-Id, EAP{Response}]
<----- PANA-Auth-Answer(y)
[Session-Id]
<----- PANA-Auth-Request(x+2)
[Session-Id, EAP{Request}]
-----> PANA-Auth-Answer(x+2) // Piggybacking EAP-Response
[Session-Id, EAP{Response}]
<----- PANA-Bind-Request(x+3)
[Session-Id, EAP{Success}, Device-Id, IP-Address,
Lifetime, Protection-Cap., PPAC, MAC]
-----> PANA-Bind-Answer(x+3)
[Session-Id, Device-Id, PPAC, MAC]
Figure 4: Example Sequence in Authentication Phase
When an EAP method that is capable of deriving keys is used during
the authentication phase and the keys are successfully derived, the
PANA-FirstAuth-End-Request and PANA-FirstAuth-End-Answer and/or
PANA-Bind-Request and PANA-Bind-Answer messages, and all subsequent
PANA messages MUST contain a MAC AVP.
The PANA-Bind-Request and the PANA-Bind-Answer message exchange is
also used for binding device identifiers of the PaC and EP(s), and
Forsberg, et al. Expires April 20, 2005 [Page 13]
Internet-Draft PANA October 2004
the IP address of the PAA to the PANA SA. To achieve this, the
PANA-Bind-Request SHOULD contain the device identifier(s) of the
EP(s) in Device-Id AVP(s) when they are either MAC or IP address(es),
and the IP address of the PAA in an IP-Address AVP. PANA-Bind-Answer
SHOULD contain PaC's device identifier in a Device-Id AVP when it is
already presented with that of EP(s). The PaC MUST use the same type
of device identifier as contained in the PANA-Bind-Request message.
This exchange when protected by a MAC AVP prevents man-in-the-middle
attacks. The PANA-Bind-Request message MAY also contain a
Protection-Capability AVP to indicate if link-layer or network-layer
ciphering should be initiated after PANA. No link layer or network
layer specific information is included in the Protection-Capability
AVP. When the information is preconfigured on the PaC and the PAA
this AVP can be omitted. It is assumed that at least PAA is aware of
the security capabilities of the access network. The PANA protocol
does not specify how the PANA SA and the Protection-Capability AVP
will be used to provide per-packet protection for data traffic.
Additionally, PANA-Bind-Request MUST include a
Post-PANA-Address-Configuration AVP, which helps PAA to inform PaC
about whether a new IP address MUST be configured and the available
methods to do so. PaC MUST include a PPAC AVP in order to indicate
its choice of method when there is a match between the methods
offered by the PAA and the methods available on the PaC. When there
is no match, a PPAC AVP MUST NOT be included and the Result-Code AVP
MUST be set to PANA_PPAC_CAPABILITY_UNSUPPORTED in the
PANA-Bind-Answer message.
PANA-Bind-Request and PANA-Bind-Answer messages MUST be retransmitted
based on the retransmission rule described in Section 5.3.
EAP authentication can fail at a pass-through authenticator without
sending an EAP-Failure message [I-D.ietf-eap-statemachine]. When
this occurs, the PAA SHOULD send a PANA-Error-Request message to the
PaC with using PANA_UNABLE_TO_COMPLY result code. The PaC SHOULD not
change its state unless the error message is secured by PANA or lower
layer. In any case, a more appropriate way is to rely on a timeout
on the PaC.
There is a case where EAP authentication succeeds with producing an
EAP-Success message but network access authorization fails due to,
e.g., authorization rejected by a AAA proxy or authorization locally
rejected by the PAA. When this occurs, the PAA MUST send
PANA-Bind-Request with a result code PANA_AUTHORIZATION_REJECTED. If
a AAA-Key is established between PaC and PAA by the time when the
EAP-Success is generated by the EAP server (this is the case when the
EAP method provides protected success indication), this PANA-Bind
message exchange MUST be protected with a MAC AVP and with carrying a
Forsberg, et al. Expires April 20, 2005 [Page 14]
Internet-Draft PANA October 2004
Key-Id AVP. The AAA-Key and the PANA session MUST be deleted after
the PANA-Bind message exchange.
4.3 Authorization Phase
Once an authentication phase or a re-authentication phase
successfully completes, the PaC gains access to the network and can
send and receive IP data traffic through EP and the PANA session
enters an authorization phase. In this phase, PANA-Ping-Request and
PANA-Ping-Answer messages are used for testing the liveness of the
PANA session on the PANA peer. Both the PaC and the PAA are allowed
to send a PANA-Ping-Request message to the communicating peer
whenever they need to make sure the availability of the session on
the peer and expect the peer to return a PANA-Ping-Answer message.
Both PANA-Ping-Request and PANA-Ping-Answer messages MUST be
protected with a MAC AVP when a PANA SA is available.
Implementations MUST limit the rate of performing this test. The PaC
and the PAA can handle rate limitation on their own, they do not have
to perform any coordination with each other. There is no negotiation
of timers for this purpose.
Figure 5 and Figure 6 show liveness tests as they are initiated by
the PaC and the PAA respectively.
PaC PAA Message(seqno)[AVPs]
------------------------------------------------------
-----> PANA-Ping-Request(q)[Session-Id, MAC]
<----- PANA-Ping-Answer(q)[Session-Id, MAC]
Figure 5: Example Sequence for PaC-initiated liveness test
PaC PAA Message(seqno)[AVPs]
------------------------------------------------------
<----- PANA-Ping-Request(p)[Session-Id, MAC]
-----> PANA-Ping-Answer(p)[Session-Id, MAC]
Figure 6: Example Sequence for PAA-initiated liveness test
4.4 Re-authentication Phase
A PANA session in an authorization phase can enter a
re-authentication phase to extend the current session lifetime by
re-executing EAP. Once the re-authentication phase successfully
completes, the session re-enters the authorization phase. Otherwise,
Forsberg, et al. Expires April 20, 2005 [Page 15]
Internet-Draft PANA October 2004
the session is deleted.
When a PaC wants to initiate re-authentication, it sends a
PANA-Reauth-Request message to the PAA. This message MUST contain a
Session-Id AVP which is used for identifying the PANA session on the
PAA. If the PAA already has an established PANA session for the PaC
with the matching identifier, it MUST first respond with a
PANA-Reauth-Answer, followed by a PANA-Auth-Request that starts a new
EAP authentication. If PAA cannot identify the session, it MUST
respond with a PANA-Error-Request with the error code
PANA_UNKNOWN_SESSION_ID. PANA-Reauth-Request/Answer messages MUST
contain a MAC AVP when PANA SA is available.
PaC may receive a PANA-Auth-Request before receiving the answer to
its outstanding PANA-Reauth-Request. This condition can arise due to
packet re-ordering or a race condition between the PaC and PAA when
they both attempt to engage in re-authentication. PaC MUST keep
discarding the received PANA-Auth-Requests until it receives the
answer to its request.
When the PAA initiates re-authentication, it sends a
PANA-Auth-Request message containing the session identifier for the
PaC to enter an authentication phase. PAA SHOULD initiate EAP
authentication before the current session lifetime expires.
Re-authentication of an on-going PANA session MUST maintain the
existing sequence numbers.
For any re-authentication, if there is an established PANA SA,
PANA-Auth-Request and PANA-Auth-Answer messages MUST be protected by
adding a MAC AVP to each message. Any subsequent EAP-based
authentication MUST be performed with the same ISP and NAP that was
selected during the initial authentication. An example sequence for
a re-authentication initiated by a PaC is shown in Figure 7.
Forsberg, et al. Expires April 20, 2005 [Page 16]
Internet-Draft PANA October 2004
PaC PAA Message(seqno)[AVPs]
------------------------------------------------------
-----> PANA-Reauth-Request(q)
[Session-Id, MAC]
<----- PANA-Reauth-Answer(q)
[Session-Id, MAC]
<----- PANA-Auth-Request(p)
[Session-Id, EAP{Request}, MAC]
-----> PANA-Auth-Answer(p) // No piggybacking EAP-Response
[Session-Id, MAC]
-----> PANA-Auth-Request(q+1)
[Session-Id, EAP{Response}, MAC]
<----- PANA-Auth-Answer(q+1) // No piggybacking EAP-Response
[Session-Id, MAC]
<----- PANA-Auth-Request(p+1)
[Session-Id, EAP{Request}, MAC]
-----> PANA-Auth-Answer(p+1) // Piggybacking EAP-Response
[Session-Id, EAP{Response}, MAC]
<----- PANA-Bind-Request(p+2)
[Session-Id, EAP{Success}, Device-Id,
IP-Address, Key-Id, Lifetime,
Protection-Cap., PPAC, MAC]
-----> PANA-Bind-Answer(p+2)
[Session-Id, Device-Id, Key-Id, PPAC, MAC]
Figure 7: Example Sequence for re-authentication initiated by PaC
4.5 Termination Phase
A procedure for explicitly terminating a PANA session can be
initiated either from the PaC (i.e., disconnect indication) or from
the PAA (i.e., session revocation). The PANA-Termination-Request and
the PANA-Termination-Answer message exchanges are used for disconnect
indication and session revocation procedures.
The reason for termination is indicated in the Termination-Cause AVP.
When there is an established PANA SA established between the PaC and
the PAA, all messages exchanged during the termination phase MUST be
protected with a MAC AVP. When the sender of the
PANA-Termination-Request receives a valid acknowledgment, all states
maintained for the PANA session MUST be deleted immediately.
Forsberg, et al. Expires April 20, 2005 [Page 17]
Internet-Draft PANA October 2004
PaC PAA Message(seqno)[AVPs]
------------------------------------------------------
-----> PANA-Termination-Request(q)[Session-Id, MAC]
<----- PANA-Termination-Answer(q)[Session-Id, MAC]
Figure 8: Example Sequence for Session Termination
Forsberg, et al. Expires April 20, 2005 [Page 18]
Internet-Draft PANA October 2004
5. Protocol Design Details and Processing Rules
5.1 Payload Encoding
The payload of any PANA message consists of zero or more AVPs
(Attribute Value Pairs). A brief description of the AVPs defined in
this document is listed below:
o Cookie AVP: contains a random value that is used for making
handshake robust against blind resource consumption DoS attacks.
o Protection-Capability AVP: contains information which protection
should be initiated after the PANA exchange (e.g., link-layer or
network layer protection).
o Device-Id AVP: contains a device identifier of the PaC or an EP.
A device identifier is represented as a pair of device identifier
type and device identifier value. Either a layer-2 address or an
IP address is used for the device identifier value when this AVP
is present.
o EAP AVP: contains an EAP PDU.
o MAC AVP: contains a Message Authentication Code that protects a
PANA message PDU.
o Termination-Cause AVP: contains the reason of session termination.
o Result-Code AVP: contains information about the protocol execution
results.
o Session-Id AVP: contains the session identifier value.
o Session-Lifetime AVP: contains the duration of authorized access.
o Failed-AVP: contains the offending AVP that caused a failure.
o NAP-Information AVP, ISP-Information AVP: contains the information
on a NAP and an ISP, respectively.
o Key-Id AVP: contains a AAA-Key identifier.
o PPAC AVP: Post-PANA-Address-Configuration AVP. Conveys the list
of IP address configuration methods available when sent by the
PAA, and the chosen method when sent by the PaC.
o Nonce AVP: contains a randomly chosen value.
Forsberg, et al. Expires April 20, 2005 [Page 19]
Internet-Draft PANA October 2004
o IP-Address AVP: contains an IP Address of a PaC.
5.2 Transport Layer
PANA uses UDP as its transport layer protocol. The UDP port number
is TBD. All messages except for PANA-PAA-Discover are always
unicast. PANA-PAA-Discover MAY be unicast when the PaC knows the IP
address of the PAA.
5.2.1 Fragmentation
PANA does not provide fragmentation of PANA messages. Instead, it
relies on fragmentation provided by EAP methods and IP layer when
needed.
5.3 Sequence Number and Retransmission
PANA uses sequence numbers to provide ordered and reliable delivery
of messages.
PaC and PAA maintain two sequence numbers: the next one to be used
for a request it initiates and the next one it expects to see in a
request from the other end. These sequence numbers are 32-bit
unsigned numbers. They are monotonically incremented by 1 as new
requests are generated and received, and wrapped to zero on the next
message after 2^32-1. Answers always contain the same sequence
number as the corresponding request. Retransmissions maintain the
same sequence number.
The initial sequence numbers (ISN) are randomly picked by PaC and PAA
as they send their very first request messages. PANA-PAA-Discover
message carries sequence number 0.
When a request message is received, it is considered valid in terms
of sequence numbers if and only if its sequence number matches the
expected value. This check does not apply to PANA-PAA-Discover, and
the very first request messages.
When an answer message is received, it is considered valid in terms
of sequence numbers if and only if its sequence number matches that
of the currently outstanding request. A peer can only have one
outstanding request at a time.
PANA messages are retransmitted based on timer at until a response is
received (in which case the retransmission timer is stopped) or the
number of retransmission reaches the maximum value (in which case the
PANA session MUST be deleted immediately). The retransmission timer
SHOULD be calculated as described in [RFC2988] to provide congestion
Forsberg, et al. Expires April 20, 2005 [Page 20]
Internet-Draft PANA October 2004
control. See Section 9 for default timer and maximum retransmission
count parameters.
PaC and PAA MUST respond to duplicate requests. Last transmitted
PANA answer MAY be cached in case it is not received by the peer and
that generates a retransmission of the last request. When available,
a cached answer can be used instead of fully processing the
retransmitted request and forming a new answer from scratch.
PANA MUST NOT generate EAP message duplication. EAP payload of a
retransmitted PANA message MUST NOT be passed to the EAP layer.
5.4 Message Authentication Code
A PANA message can contain a MAC (Message Authentication Code) AVP
for cryptographically protecting the message.
When a MAC AVP is included in a PANA message, the value field of the
MAC AVP is calculated by using the PANA_MAC_KEY in the following way:
MAC AVP value = PANA_MAC_PRF(PANA_MAC_KEY, PANA_PDU)
where PANA_PDU is the PANA message including the PANA header, with
the MAC AVP value field first initialized to 0. PANA_MAC_PRF
represents the pseudo random function corresponding to the MAC
algorithm specified in the MAC AVP. In this version of draft,
PANA_MAC_PRF is HMAC-SHA1. The PaC and PAA MUST use the same
algorithm to calculate a MAC AVP they originate and receive. The
algorithm is determined by the PAA when a PANA-Bind-Request with a
MAC AVP is sent. When the PaC does not support the MAC algorithm
specified in the PANA-Bind-Request message, it MUST silently discard
the message. The PAA MUST NOT change the MAC algorithm throughout
the continuation of the PANA session.
5.5 Message Validity Check
When a PANA message is received, the message is considered to be
invalid at least when one of the following conditions are not met:
o The IP Hop Limit (or TTL) field has a value of 255, i.e., the
packet could not possibly have been forwarded by a router.
o Each field in the message header contains a valid value including
sequence number, message length, message type, version number,
flags, etc.
o When a device identifier of the PaC is bound to the PANA session,
it matches the device identifier carried in MAC or or IP header,
Forsberg, et al. Expires April 20, 2005 [Page 21]
Internet-Draft PANA October 2004
or other locally-significant identifier provided by the
lower-layers (e.g., circuit ID) unless the message is a
PANA-Update-Request with an IP-Address AVP.
o The message type is one of the expected types in the current
state. Specifically the following messages are unexpected and
invalid:
* In discovery and handshake phase:
+ PANA-Termination-Request and PANA-Ping-Request.
+ PANA-Bind-Request.
+ PANA-Update-Request.
* In authentication phase:
+ PANA-PAA-Discover.
+ PANA-Update-Request.
+ PANA-Start-Request after a PaC receives the first valid
PANA-Auth-Request.
+ PANA-Termination-Request before the PaC receives the first
successful PANA-Bind-Request.
* After successful PANA authentication:
+ PANA-Start-Request as well as a non-duplicate
PANA-Bind-Request.
+ PANA-PAA-Discover.
* In termination phase:
+ PANA-PAA-Discover.
+ All requests but PANA-Termination-Request.
o The message payload contains a valid set of AVPs allowed for the
message type and there is no missing AVP that needs to be included
in the payload.
o Each AVP is decoded correctly.
Forsberg, et al. Expires April 20, 2005 [Page 22]
Internet-Draft PANA October 2004
o When a MAC AVP is included, the AVP value matches the MAC value
computed against the received message.
o When a Device-Id AVP is included, the AVP is valid if the device
identifier type contained in the AVP is supported (check performed
by both PaC and PAA) and is the requested one (check performed by
PAA only) and the device identifier value contained in the AVP
matches the value extracted from the lower-layer encapsulation
header corresponding to the device identifier type contained in
the AVP (check performed by PAA only). Note that a Device-Id AVP
carries the PaC's device identifier in messages from PaC to PAA
and EP(s)' device identifier in messages from PAA to PaC.
o When an IP-Address AVP is received in a message, the AVP is valid
if the IP address matches the source address in the IP header.
Invalid messages MUST be discarded in order to provide robustness
against DoS attacks. In addition, an error notification message MAY
be returned to the sender. See Section 5.7 for details.
5.6 PANA Security Association
A PANA SA is created as an attribute of a PANA session when EAP
authentication succeeds with a creation of a AAA-Key. A PANA SA is
not created when the PANA authentication fails or no AAA-Key is
produced by any EAP authentication method. In the case where two EAP
authentications are performed in sequence in a single PANA
authentication phase, it is possible that two AAA-Keys are derived.
If this happens, the PANA SA MUST be generated from both AAA-Keys.
When a new AAA-Key is derived as a result of EAP-based
re-authentication, any key derived from the old AAA-Key MUST be
updated to a new one that is derived from the new AAA-Key. In order
to distinguish the new AAA-Key from old ones, one Key-Id AVP MUST be
carried in PANA-Bind-Request and PANA-Bind-Answer messages or
PANA-FirstAuth-End-Request and PANA-FirstAuth-End-Answer messages at
the end of the EAP authentication which resulted in deriving a new
AAA-Key. The Key-Id AVP is of type Unsigned32 and MUST contain a
value that uniquely identifies the AAA-Key within the PANA session.
The PANA-Bind-Answer message (or the PANA-FirstAuth-End-Answer
message) sent in response to a PANA-Bind-Request message (or a
PANA-FirstAuth-End-Request message) with a Key-Id AVP MUST contain a
Key-Id AVP with the same AAA-Key identifier carried in the request.
PANA-Bind-Request, PANA-Bind-Answer, PANA-FirstAuth-End-Request and
PANA-FirstAuth-End-Answer messages with a Key-Id AVP MUST also carry
a MAC AVP whose value is computed by using the new PANA-MAC-KEY
derived from the new AAA-Key (or the new pair of AAA-Keys when the
PANA_MAC_KEY is derived from two AAA-Keys). Although the
specification does not mandate a particular method for calculation of
Forsberg, et al. Expires April 20, 2005 [Page 23]
Internet-Draft PANA October 2004
Key-Id AVP value, a simple method is to use monotonically increasing
numbers.
The created PANA SA is deleted when the corresponding PANA session is
deleted. The lifetime of the PANA SA is the same as the lifetime of
the PANA session for simplicity.
PANA SA attributes as well as PANA session attributes are listed
below:
PANA Session attributes:
* Session-Id
* Device-Id of PaC
* IP address of PaC (may be the same as the Device-Id of PaC)
* IP address of PAA
* List of device identifiers of EPs
* Sequence number of the last transmitted request
* Sequence number of the last received request
* Last transmitted message payload
* Retransmission interval
* Session lifetime
* Protection-Capability
* PANA SA attributes:
+ Nonce generated by PaC (PaC_nonce)
+ Nonce generated by PAA (PAA_nonce)
+ AAA-Key
+ AAA-Key Identifier
+ PANA_MAC_KEY
The PANA_MAC_KEY is used to integrity protect PANA messages and
derived from AAA-Key(s). When two AAA-Keys (AAA-Key1 and AAA-Key2)
Forsberg, et al. Expires April 20, 2005 [Page 24]
Internet-Draft PANA October 2004
are generated as a result of double EAP authentication (see Section
4.2) the compound AAA-Key can be computed as follows ('|' indicates
concatenation):
AAA-Key = AAA-Key1 | AAA-Key2
The PANA_MAC_KEY is computed in the following way:
PANA_MAC_KEY = The first N bits of
HMAC_SHA1(AAA-Key, PaC_nonce | PAA_nonce | Session-ID)
where the value of N depends on the integrity protection algorithm in
use, i.e., N=160 for HMAC-SHA1. The length of AAA-Key MUST be N bits
or longer. See Section Section 5.4 for the detailed usage of the
PANA_MAC_KEY.
5.7 Error Handling
A PANA-Error-Request message MAY be sent by either the PaC or the PAA
when a badly formed PANA message is received or in case of other
errors. The receiver of this request MUST respond with a
PANA-Error-Answer message. If the cause of this error message was a
request message (e.g., PANA-PAA-Discover or *-Request), then the
request MAY be retransmitted immediately without waiting for its
retransmission timer to go off. If the cause of the error was a
response message, the receiver of the PANA-Error-Request message
SHOULD NOT resend the same response until it receives the next
request.
To defend against DoS attacks a timer MAY be used. One (1) error
notification is sent to each different sender each N seconds. N is a
configurable parameter.
When an error message is sent unprotected with a MAC AVP and the
lower-layer is insecure, the error message is treated as an
informational message. The receiver of such an error message MUST
NOT change its state unless the error persists and the PANA session
is not making any progress.
5.8 Device ID Choice
The device identifier used in the context of PANA can be an IP
address, a MAC address, or an identifier that is not carried in data
packets but has local significance in identifying a connected host
(e.g., circuit id, PPP interface id). The last type of identifiers
are commonly used in point-to-point links where MAC addresses are not
available and lower-layers are already physically or
Forsberg, et al. Expires April 20, 2005 [Page 25]
Internet-Draft PANA October 2004
cryptographically secured.
It is assumed that the PAA knows the link type and the security
mechanisms being provided or required on the access network (e.g.,
based on physical security, link-layer ciphers enabled before or
after PANA, or IPsec). Based on that information, the PAA can decide
what type of EP device id will be used when running PANA with the
client. When IPsec-based security [I-D.ietf-pana-ipsec] is the
choice of access control, the PAA SHOULD provide IP address(es) as
EP(s)' device ID, and expect the PaC to provide its IP address in
return. In case IPsec is not used, MAC addresses are used as device
IDs when available. If non-IPsec access control is enabled, and a
MAC address is not available, device ID exchange does not occur
within PANA. Instead, peers rely on lower-layers to provide
locally-significant identifiers along with received PANA packets.
5.9 Updating PaC' Address
A PaC's IP address can change in certain situations. For example,
the PANA framework [I-D.ietf-pana-framework] describes a case in
which a PaC replaces a pre-PANA address (PRPA) with a post-PANA
address (POPA), and the PaC and PAA create host routes to each other
in order to maintain on-link communication based on the POPA. The
PAA needs to be notified about the change of PaC address.
After the PaC has changed its address, it MUST send a
PANA-Update-Request message to the PAA. The message MUST carry the
new PaC address in an IP-Address AVP. If the address contained in
the request is invalid, the PAA MUST send a PANA-Error message with
the result code PANA_INVALID_IP_ADDRESS. Otherwise, the PAA MUST
update the PANA session with the new PaC address and return a
PANA-Update-Answer message. If there is an established PANA SA, both
PANA-Update-Request and PANA-Update-Answer messages MUST be protected
with a MAC AVP.
5.10 Session Lifetime
The authentication phase determines the PANA session lifetime when
the network access authorization succeeds. The Session-Lifetime AVP
MAY be optionally included in the PANA-Bind-Request message to inform
PaC about the valid lifetime of the PANA session. It MUST be ignored
when included in other PANA messages. When there are multiple EAP
authentication taking place, this AVP SHOULD be included after the
final authentication.
The lifetime is a non-negotiable parameter that can be used by PaC to
manage PANA-related state. PaC does not have to perform any actions
when the lifetime expires, other than optionally purging local state.
Forsberg, et al. Expires April 20, 2005 [Page 26]
Internet-Draft PANA October 2004
PAA SHOULD initiate EAP authentication before the current session
lifetime expires.
PaC and PAA MAY optionally rely on lower-layer indications to
expedite the detection of a disconnected peer. Availability and
reliability of such indications depend on the specific access
technologies. PANA peer can use PANA-Ping-Request message to verify
the disconnection before taking an action.
The session lifetime parameter is not related to the transmission of
PANA-Ping-Request messages. These messages can be used for
asynchronously verifying the liveness of the peer. The decision to
send PANA-Ping-Request message is taken locally and does not require
coordination between the peers.
5.11 Network Selection
In a discovery and handshake phase, a PANA-Start-Request message sent
from the PAA MAY contain zero or one NAP-Information AVP and zero or
more ISP-Information AVPs to advertise the information on the NAP
and/or ISPs. The PaC MAY indicate its choice of ISP by including an
ISP-Information AVP in the PANA-Start-Answer message. When a AAA
backend is used, the identity of the destination AAA server or realm
MUST be determined based on the explicitly chosen ISP. When the
ISP-Information AVP is not present, the access network MAY rely on
the client identifier carried in the EAP authentication method to
make this determination. The PaC can choose an ISP and contain an
ISP-Information AVP for the chosen ISP in a PANA-Start-Answer message
even when there is no ISP-Information AVP contained in the
PANA-Start-Request message.
5.12 Separate NAP and ISP Authentication
PANA allows running at most two EAP sessions in sequence in an
authentication phase to support separate NAP and ISP authentication
as described in next sections. Currently, running multiple EAP
sessions in sequence in an authentication phase is designed only for
separate NAP and ISP authentication. It is not for running arbitrary
number of EAP sessions in sequence, or giving the PaC another chance
to try another EAP authentication method within an integrated NAP and
ISP authentication when an EAP authentication method fails. Within
separate NAP and ISP authentication, the NAP authentication and the
ISP authentication are considered completely independent. Presence
or success of one should not effect the other. Making a network
access authorization decision based on the success or failure of each
authentication is a network policy issue.
Forsberg, et al. Expires April 20, 2005 [Page 27]
Internet-Draft PANA October 2004
5.12.1 Negotiating Separate NAP and ISP Authentication
When the PaC and PAA negotiates in the discovery and handshake phase
to perform separate NAP and ISP authentication, the PaC and the PAA
operate in the following way in addition to the behavior defined in
Section 4.1
In the discovery and handshake phase, the PAA MAY enable separate NAP
and ISP authentication ([I-D.ietf-pana-framework]) by setting the
S-flag of the message header of the PANA-Start-Request.
If the S-flag of the received PANA-Start-Request message is not set,
the PaC MUST NOT set the S-flag in the PANA-Start-Answer message sent
back to the PAA.
If the S-flag of the received PANA-Start-Request message is set, the
PaC can indicate its desire to perform separate NAP and ISP
authentication by setting the S-flag in the PANA-Start-Answer
message. If the S-flag in the PANA-Start-Answer message is not set,
only one authentication is performed and the processing occurs as
described in Section 4.1. If the S-flag in the PANA-Start-Answer
message is set, the determination of the destination AAA server or
realm for ISP authentication is performed as described in Section
5.11. In addition, where backend AAA servers are used for NAP
authentication, the NAP is considered the ultimate AAA realm, and the
destination AAA server for this authentication is determined entirely
by the local configuration on the access server hosting the PAA
(NAS).
When the S-flag is set in a PANA-Start-Request message, the initial
EAP Request MUST NOT be carried in the PANA-Start-Request message.
(If the initial EAP Request were contained in the PANA-Start-Request
message during the S-flag negotiation, the PaC cannot tell whether
the EAP Request is for NAP authentication or ISP authentication.)
5.12.2 Execution of Separate NAP and ISP Authentication
When the PaC and PAA have negotiated in the discovery and handshake
phase to perform separate NAP and ISP authentication, the PaC and the
PAA operate in the following way in addition to the behavior defined
in Section 4.2
o The S-flag of PANA-Auth-Request and PANA-Auth-Answer messages MUST
be set.
o An EAP Success/Failure message is carried in a
PANA-FirstAuth-End-Request (PFER) message as well as a
Forsberg, et al. Expires April 20, 2005 [Page 28]
Internet-Draft PANA October 2004
PANA-Bind-Request (PBR) message. The PANA-FirstAuth-End-Request
message MUST be used at the end of the first EAP authentication
and the PANA-Bind-Request MUST be used for the second EAP
authentication. The PANA-FirstAuth-End-Request messages MUST be
acknowledged with a PANA-FirstAuth-End-Answer (PFEA) message.
o If the first EAP authentication has failed, the PAA can choose not
to perform the second EAP authentication by clearing the S-flag of
the PANA-FirstAuth-End-Request message. In this case, the S-flag
of the PANA-FirstAuth-End-Answer message sent by the PaC MUST be
cleared. If the S-flag of the PANA-FirstAuth-End-Request message
is set when the first EAP authentication has failed, the PaC can
choose not to perform the second EAP authentication by clearing
the S-flag of the PANA-FirstAuth-End-Answer message. If the first
EAP authentication failed and the S-flag is not set in the
PANA-FirstAuth-End-Answer message as a result of those operations,
the PANA session MUST be immediately deleted. Otherwise, the
second EAP authentication MUST be performed.
o The PAA determines the execution order of NAP authentication and
ISP authentication. In this case, the PAA can indicate which
authentication (NAP authentication or ISP authentication) is
currently occurring by using N-flag in the PANA message header.
When NAP authentication is being performed, the N-flag MUST be
set. When ISP authentication is being performed, the N-flag MUST
NOT be set. The N-flag MUST NOT be set when S-flag is not set.
5.12.3 AAA-Key Calculation
When the PaC and PAA have negotiated in the discovery and handshake
phase to perform separate NAP and ISP authentication, if the
lower-layer is insecure, the two EAP authentication methods used in
the separate authentication MUST be capable of deriving keys. In
this case, if the first EAP authentication is successful, the
PANA-FirstAuth-End-Request and PANA-FirstAuth-End-Answer messages as
well as PANA-Auth-Request and PANA-Auth-Answer messages in the second
EAP authentication MUST be protected with the key derived from the
AAA-Key for the first EAP authentication. The PANA-Bind-Request and
PANA-Bind-Answer messages and all subsequent PANA messages exchanged
in authorized phase, re-authentication phase and termination phase
MUST be protected either with the AAA-Key for the first EAP
authentication if the first EAP authentication succeeds and the
second EAP authentication fails, or with the AAA-Key for the second
EAP authentication if the first EAP authentication fails and the
second EAP authentication succeeds, or with the compound AAA-Key
derived from the two AAA-Keys, one for the first EAP authentication
and the other from the second EAP authentication, if both the first
and second EAP authentications succeed.
Forsberg, et al. Expires April 20, 2005 [Page 29]
Internet-Draft PANA October 2004
5.12.4 Re-authentication
When separate ISP and NAP authentication is performed, it is possible
that different authorization lifetime values are associated with the
two authentications. In this case, the smaller authorization
lifetime value MUST be used for calculating the PANA Session-Lifetime
value. As a result, when entering a re-authentication phase, both
NAP and ISP authentication will be performed in the same
re-authentication phase.
5.12.5 Example Sequence
A PANA message sequence with separate NAP and ISP authentication is
illustrated in Figure 9. The example assumes the following scenario:
o The PaC initiates the discovery and handshake phase.
o The PAA offers separate NAP and ISP authentication, as well as a
choice of ISP from "ISP1" and "ISP2". The PaC accepts the offer
from PAA, with choosing "ISP1" as the ISP.
o NAP authentication and ISP authentication is performed in this
order in authentication phase.
o An EAP authentication method with a single round trip is used in
each EAP sequence.
o After a PANA SA is established, all messages are integrity and
replay protected with MAC AVPs.
o Authorization, re-authentication and termination phases are not
shown.
PaC PAA Message(seqno)[AVPs]
-----------------------------------------------------
// Discovery and handshake phase
-----> PANA-PAA-Discover(0)
<----- PANA-Start-Request(x) // S-flag set
[Nonce, Cookie,
ISP-Information("ISP1"),
ISP-Information("ISP2"),
NAP-Information("MyNAP")]
-----> PANA-Start-Answer(x) // S-flag set
[Nonce, Cookie, // PaC chooses "ISP1"
ISP-Information("ISP1")]
// Authentication phase
Forsberg, et al. Expires April 20, 2005 [Page 30]
Internet-Draft PANA October 2004
<----- PANA-Auth-Request(x+1) // NAP authentication
[Session-Id, EAP{Request}] // S- and N-flags set
-----> PANA-Auth-Answer(x+1) // S- and N-flags set
[Session-Id] // No piggybacking
-----> PANA-Auth-Request(y) // S- and N-flags set
[Session-Id, EAP{Response}]
<----- PANA-Auth-Answer(y)[Session-Id] // S- and N-flags set
<----- PANA-Auth-Request(x+2) // S- and N-flags set
[Session-Id, EAP{Request}]
-----> PANA-Auth-Answer(x+2) // S- and N-flags set
[Session-Id, EAP{Response}] // Piggybacking
<----- PANA-FirstAuth-End-Request(x+3) // S- and N-flags set
[Session-Id, EAP{Success}, Key-Id, MAC]
-----> PANA-FirstAuth-End-Answer(x+3) // S- and N-flags set
[Session-Id, Key-Id, MAC]
<----- PANA-Auth-Request(x+4) // ISP authentication
[Session-Id, EAP{Request}, MAC] // S-flag set
-----> PANA-Auth-Answer(x+4) // S-flag set
[Session-Id, MAC] // No piggybacking
-----> PANA-Auth-Request(y+1) // S-flag set
[Session-Id, EAP{Response}, MAC]
<----- PANA-Auth-Answer(y+1) // S-flag set
[Session-Id, MAC]
<----- PANA-Auth-Request(x+5) // S-flag set
[Session-Id, EAP{Request}, MAC]
-----> PANA-Auth-Answer(x+5) // S-flag set
[Session-Id, EAP{Response}, MAC] // Piggybacking
<----- PANA-Bind-Request(x+6) // S-flag set
[Session-Id, EAP{Success}, Device-Id,
IP-Address, Key-Id, Lifetime,
Protection-Cap., PPAC, MAC]
-----> PANA-Bind-Answer(x+6) // S-flag set
[Session-Id, Device-Id, Key-Id,
PPAC, MAC]
Figure 9: A Complete Message Sequence for Separate NAP and ISP
Authentication
Forsberg, et al. Expires April 20, 2005 [Page 31]
Internet-Draft PANA October 2004
6. Security and Mobility
6.1 PANA Security Association Establishment
When PANA is used over an already established secure channel, such as
physically secured wires or ciphered link-layers, we can reasonably
assume that man-in-the-middle attacks or service theft is not
possible. See [I-D.ietf-pana-threats-eval] for a detailed
discussion.
In environments where no secure channel prior to the PANA execution
is available, PANA needs to protect itself against a number of
attacks. The device identifier that is used during the
authentication needs to be verified at the end of the authentication
to prevent service theft and DoS attacks. Additionally, a free
loader should be prevented from spoofing data packets by using the
device identifier of an already authorized legitimate client. Both
of these requirements necessitate generation of a security
association between the PaC and the PAA at the end of the
authentication. This can only be done when the authentication method
used can generate session keys. Use of session keys can prevent
attacks which would otherwise be very easy to launch by eavesdropping
on and spoofing traffic over an insecure link.
The EAP method provided session key is transported to the PAA (if
necessary) and is subsequently input to the creation of the PANA SA.
Applying the PANA SA to the messages exchanged during the final PANA
handshake provides implicit key confirmation to both the PAA and the
PaC. Implicit key confirmation shows both, the PaC and the PAA, that
they possess the unique and fresh session key.
Protecting the final PANA handshake also ensures that the device
identifier (and other information) cannot be modified by an
adversary. Further usage of the keying material is discussed in
[I-D.ietf-pana-framework].
6.2 Mobility
A mobile PaC's network access authentication performance can be
enhanced by deploying a context-transfer-based mechanism, where some
session attributes are transferred from the previous PAA to the new
one in order to avoid performing a full EAP authentication (reactive
approach). Additional mechanisms that are based on the proactive AAA
state establishment at one or more candidate PAAs may be developed in
the future [I-D.irtf-aaaarch-handoff]. The details of a
context-transfer-based mechanism is provided in this section.
Upon changing its point of attachment, a PaC that wants to quickly
Forsberg, et al. Expires April 20, 2005 [Page 32]
Internet-Draft PANA October 2004
resume its ongoing PANA session without running EAP MAY send its
unexpired PANA session identifier in its PANA-Start-Answer message.
Along with the Session-Id AVP, a MAC AVP MUST be included in this
message. The MAC AVP is computed by using the PANA_MAC_KEY shared
between the PaC and its previous PAA that has an unexpired PANA
session with the PaC. This action signals PaC's desire to perform
the mobility optimization. In the absence of a Session-Id AVP in
this message, the PANA session takes its usual course (i.e.,
EAP-based authentication is performed).
If a PAA receives a session identifier in the PANA-Start-Answer
message, and it is configured to enable this optimization, it SHOULD
retrieve the PANA session attributes from the previous PAA. Current
PAA determines the identity of the previous PAA by looking at the
DiameterIdentity part of the PANA session identifier. The MAC AVP
can only be verified by the previous PAA, therefore a copy of the
PANA message SHOULD be provided to the previous PAA. The mechanism
required to send a copy of the PANA-Start-Answer message from current
PAA to the previous PAA, and retrieve the session attributes is
outside the scope of PANA protocol. The Context Transfer Protocol
[I-D.ietf-seamoby-ctp] might be useful for this purpose.
When the previous or current PAA is not configured to enable this
optimization, the current PAA can not retrieve the PANA session
attributes, or the PANA session has already expired (i.e., session
lifetime is zero), the PAA MUST send the PANA-Auth-Request message
with a new session identifier and let the PANA exchange take its
usual course. This action will engage EAP-based authentication and
create a fresh PANA session from scratch.
In case the current PAA can retrieve the on-going PANA session
attributes from the previous PAA, the PANA session continues with a
PANA-Bind exchange.
As part of the context transfer, an intermediate AAA-Key material is
provided by the previous PAA to the current PAA.
AAA-Key-int = The first N bits of
HMAC-SHA1(AAA-Key, DiameterIdentity | Session-ID)
The value of N depends on the integrity protection algorithm in use,
i.e., N=160 for HMAC-SHA1. DiameterIdentity is the identifier of the
current PAA. Session-ID is the identifier of the PaC's PANA session
with the previous PAA.
The current PAA and PaC compute the new AAA-Key by using the nonce
values and the AAA-Key-int.
Forsberg, et al. Expires April 20, 2005 [Page 33]
Internet-Draft PANA October 2004
AAA-Key-new = The first N bits of
HMAC-SHA1(AAA-Key-int, PaC_nonce | PAA_nonce)
New PANA_MAC_KEY is computed based on the algorithm described in
Section 5.6, by using the new AAA-Key and the new Session-ID assigned
by the current PAA. The MAC AVP contained in the PANA-Bind-Request
and PANA-Bind-Answer messages MUST be generated and verified by using
the new PANA_MAC_KEY. The Session-ID AVP MUST include a new session
identifier assigned by the current PAA. A new PANA session is
created upon successful completion of this exchange.
Note that correct operation of this optimization relies on many
factors, including applicability of authorization state from one
network attachment to another. [I-D.ietf-eap-keying] identifies this
operation as "fast handoff" and provides deployment considerations.
Operators are recommended to take those guidelines into account when
using this optimization in their networks.
Forsberg, et al. Expires April 20, 2005 [Page 34]
Internet-Draft PANA October 2004
7. PANA Headers and Formats
This section defines message formats for PANA protocol.
7.1 IP and UDP Headers
The Hop Limit (or TTL) field of the IP header MUST be set to 255.
When a PANA-PAA-Discover message is multicast, IP destination address
of the message is set to a well-known link-local multicast address
(TBD). A PANA-PAA-Discover message MAY be unicast in some cases as
specified in Section 4.1. Any other PANA packet is unicast between
the PaC and the PAA. The source and destination addresses SHOULD be
set to the addresses on the interfaces from which the message will be
sent and received, respectively.
When the PANA packet is sent in response to a request, the UDP source
and destination ports of the response packet MUST be copied from the
destination and source ports of the request packet, respectively.
The destination port of an unsolicited PANA packet MUST be set to an
assigned value (TBD), and the source port MUST be set to a value
chosen by the sender.
7.2 PANA Header
A summary of the PANA header format is shown below. The fields are
transmitted in network byte order.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Reserved | Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AVPs ...
+-+-+-+-+-+-+-+-+-+-+-+-+-
Version
This Version field MUST be set to 1 to indicate PANA Version 1.
Forsberg, et al. Expires April 20, 2005 [Page 35]
Internet-Draft PANA October 2004
Reserved
This 8-bit field is reserved for future use, and MUST be set to
zero, and ignored by the receiver.
Message Length
The Message Length field is three octets and indicates the length
of the PANA message including the header fields.
Flags
The Flags field is eight bits. The following bits are assigned:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R S N r r r r r r r r r r r r r|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
R(equest)
If set, the message is a request. If cleared, the message is
an answer.
S(eparate)
When the S-flag is set in a PANA-Start-Request message it
indicates that PAA is willing to offer separate NAP and ISP
authentication. When the S-flag is set in a PANA-Start-Answer
message it indicates that the PaC accepts on performing
separate NAP and ISP authentication. When the S-flag is set in
a PANA-Auth-Request/Answer, PANA-FirstAuth-End-Request/Answer
and PANA-Bind-Request/Answer messages it indicates that
separate NAP and ISP authentication is being performed in the
authentication phase. For other cases, S-flag MUST NOT be set.
N(AP authentication)
When the N-flag is set in a PANA-Auth-Request message, it
indicates that the current EAP authentication is for NAP
authentication. When the N-flag is unset in a
PANA-Auth-Request message, it indicates that the current EAP
authentication is for ISP authentication. The PaC MUST copy
the value of the flag in its requests from the last received
request of the PAA. The value of the flag on an answer MUST be
copied from the request. The N-flag MUST NOT be set when
Forsberg, et al. Expires April 20, 2005 [Page 36]
Internet-Draft PANA October 2004
S-flag is not set.
r(eserved)
these flag bits are reserved for future use, and MUST be set to
zero, and ignored by the receiver.
Message Type
The Message Type field is two octets, and is used in order to
communicate the message type with the message. The 16-bit address
space is managed by IANA [ianaweb]. PANA uses its own address
space for this field.
Sequence Number
The Sequence Number field contains a 32 bit value.
AVPs
AVPs are a method of encapsulating information relevant to the
PANA message. See section Section 7.3 for more information on
AVPs.
7.3 AVP Header
Each AVP of type OctetString MUST be padded to align on a 32-bit
boundary, while other AVP types align naturally. A number of
zero-valued bytes are added to the end of the AVP Data field till a
word boundary is reached. The length of the padding is not reflected
in the AVP Length field [RFC3588].
The fields in the AVP header MUST be sent in network byte order. The
format of the header is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AVP Code | AVP Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AVP Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Id (opt) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data ...
+-+-+-+-+-+-+-+-+
Forsberg, et al. Expires April 20, 2005 [Page 37]
Internet-Draft PANA October 2004
AVP Code
The AVP Code, combined with the Vendor-Id field, identifies the
attribute uniquely. AVP numbers are allocated by IANA [ianaweb].
PANA uses its own address space for this field although some of
the AVP formats are borrowed from Diameter protocol [RFC3588].
AVP Flags
The AVP Flags field is two octets. The following bits are
assigned:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V M r r r r r r r r r r r r r r|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
M(andatory)
The 'M' Bit, known as the Mandatory bit, indicates whether
support of the AVP is required.
V(endor)
The 'V' bit, known as the Vendor-Specific bit, indicates
whether the optional Vendor-Id field is present in the AVP
header.
r(eserved)
These flag bits are reserved for future use, and MUST be set to
zero, and ignored by the receiver.
AVP Length
The AVP Length field is four octets, and indicates the number of
octets in this AVP including the AVP Code, AVP Length, AVP Flags,
and the AVP data.
Reserved
This two-octet field is reserved for future use, and MUST be set
to zero, and ignored by the receiver.
Forsberg, et al. Expires April 20, 2005 [Page 38]
Internet-Draft PANA October 2004
Vendor-Id
The Vendor-Id field is present if the 'V' bit is set in the AVP
Flags field. The optional four-octet Vendor-Id field contains the
IANA assigned "SMI Network Management Private Enterprise Codes"
[ianaweb] value, encoded in network byte order. Any vendor
wishing to implement a vendor-specific PANA AVP MUST use their own
Vendor-Id along with their privately managed AVP address space,
guaranteeing that they will not collide with any other vendor's
vendor-specific AVP(s), nor with future IETF applications.
Data
The Data field is zero or more octets and contains information
specific to the Attribute. The format and length of the Data
field is determined by the AVP Code and AVP Length fields.
Forsberg, et al. Expires April 20, 2005 [Page 39]
Internet-Draft PANA October 2004
8. PANA Messages, Message Specifications and AVPs
8.1 PANA Messages
Figure 10 lists all PANA messages defined in this document.
Message Direction: PaC---PAA
----------------------------------------
PANA-PAA-Discover -------->
PANA-Start-Request <--------
PANA-Start-Answer -------->
PANA-Auth-Request <------->
PANA-Auth-Answer <------->
PANA-Reauth-Request -------->
PANA-Reauth-Answer <--------
PANA-FirstAuth-End-Request <--------
PANA-FirstAuth-End-Answer -------->
PANA-Bind-Request <--------
PANA-Bind-Answer -------->
PANA-Ping-Request <------->
PANA-Ping-Answer <------->
PANA-Termination-Request <------->
PANA-Termination-Answer <------->
PANA-Update-Request -------->
PANA-Update-Answer <--------
PANA-Error-Request <------->
PANA-Error-Answer <------->
Figure 10: PANA Message Overview
8.2 Message Specifications
Every PANA message MUST include a corresponding ABNF [RFC2234]
specification found in [RFC3588].
Example:
message ::= < PANA-Header: <Message type>, [REQ] [SEP] >
Forsberg, et al. Expires April 20, 2005 [Page 40]
Internet-Draft PANA October 2004
* [ AVP ]
8.2.1 PANA-PAA-Discover (PDI)
The PANA-PAA-Discover (PDI) message is used to discover the address
of PAA(s). Both sequence numbers in this message are set to zero
(0).
PANA-PAA-Discover ::= < PANA-Header: 1 >
* [ AVP ]
8.2.2 PANA-Start-Request (PSR)
PANA-Start-Request (PSR) is sent by the PAA to the PaC. The PAA sets
the sequence number to an initial random value.
PANA-Start-Request ::= < PANA-Header: 2, REQ [SEP] >
{ Nonce }
[ Cookie ]
[ EAP-Payload ]
[ NAP-Information ]
* [ ISP-Information ]
[ Protection-Capability]
[ PPAC ]
* [ AVP ]
8.2.3 PANA-Start-Answer (PSA)
PANA-Start-Answer (PSA) is sent by the PaC to the PAA in response to
a PANA-Start-Request message.
PANA-Start-Answer ::= < PANA-Header: 2 [SEP] >
{ Nonce }
[ Session-Id ]
[ Cookie ]
[ EAP-Payload ]
[ ISP-Information ]
* [ AVP ]
0*1 < MAC >
8.2.4 PANA-Auth-Request (PAR)
PANA-Auth-Request (PAR) is sent by the PAA to the PaC.
Forsberg, et al. Expires April 20, 2005 [Page 41]
Internet-Draft PANA October 2004
PANA-Auth-Request ::= < PANA-Header: 3, REQ [SEP] [NAP] >
< Session-Id >
< EAP-Payload >
* [ AVP ]
0*1 < MAC >
8.2.5 PANA-Auth-Answer (PAN)
PANA-Auth-Answer (PAN) is sent by the PaC to the PAA in response to a
PANA-Auth-Request message.
PANA-Auth-Answer ::= < PANA-Header: 3 [SEP] [NAP] >
< Session-Id >
< EAP-Payload >
* [ AVP ]
0*1 < MAC >
8.2.6 PANA-Reauth-Request (PRAR)
PANA-Reauth-Request (PRAR) is sent by the PaC to the PAA.
PANA-Reauth-Request ::= < PANA-Header: 4, REQ >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.2.7 PANA-Reauth-Answer (PRAA)
PANA-Reauth-Answer (PRAA) is sent by the PAA to the PaC in response
to a PANA-Reauth-Request message.
PANA-Reauth-Answer ::= < PANA-Header: 4 >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.2.8 PANA-Bind-Request (PBR)
PANA-Bind-Request (PBR) is sent by the PAA to the PaC.
PANA-Bind-Request ::= < PANA-Header: 5, REQ [SEP] [NAP] >
< Session-Id >
{ Result-Code }
{ PPAC }
Forsberg, et al. Expires April 20, 2005 [Page 42]
Internet-Draft PANA October 2004
{ IP-Address }
[ EAP-Payload ]
[ Session-Lifetime ]
[ Protection-Capability ]
[ Key-Id ]
* [ Device-Id ]
* [ AVP ]
0*1 < MAC >
8.2.9 PANA-Bind-Answer (PBA)
PANA-Bind-Answer (PBA) is sent by the PaC to the PAA in response to a
PANA-Result-Request message.
PANA-Bind-Answer ::= < PANA-Header: 5 [,SEP] [NAP] >
< Session-Id >
{ Result-Code }
[ PPAC ]
[ Device-Id ]
[ Key-Id ]
* [ AVP ]
0*1 < MAC >
8.2.10 PANA-Ping-Request (PPR)
PANA-Ping-Request (PPR) is either sent by the PaC or the PAA.
PANA-Ping-Request ::= < PANA-Header: 6, REQ >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.2.11 PANA-Ping-Answer (PPA)
PANA-Ping-Answer (PPA) is sent in response to a PANA-Ping-Request.
PANA-Ping-Answer ::= < PANA-Header: 6 >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.2.12 PANA-Termination-Request (PTR)
PANA-Termination-Request (PTR) is sent either by the PaC or the PAA.
Forsberg, et al. Expires April 20, 2005 [Page 43]
Internet-Draft PANA October 2004
PANA-Termination-Request ::= < PANA-Header: 7, REQ >
< Session-Id >
< Termination-Cause >
* [ AVP ]
0*1 < MAC >
8.2.13 PANA-Termination-Answer (PTA)
PANA-Termination-Answer (PTA) is sent either by the PaC or the PAA in
response to PANA-Termination-Request.
PANA-Termination-Answer ::= < PANA-Header: 7 >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.2.14 PANA-Error-Request (PER)
PANA-Error is sent either by the PaC or the PAA.
PANA-Error-Request ::= < PANA-Header: 8 REQ >
< Session-Id >
< Result-Code >
{ Failed-AVP }
* [ AVP ]
0*1 < MAC >
8.2.15 PANA-Error-Answer (PEA)
PANA-Error-Answer is sent in response to a PANA-Error-Request.
PANA-Error-Answer ::= < PANA-Header: 8 >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.2.16 PANA-FirstAuth-End-Request (PFER)
PANA-FirstAuth-End-Request (PFER) is sent by the PAA to the PaC.
PANA-FirstAuth-End-Request ::= < PANA-Header: 9, REQ [SEP] [NAP] >
< Session-Id >
{ EAP-Payload }
{ Result-Code }
Forsberg, et al. Expires April 20, 2005 [Page 44]
Internet-Draft PANA October 2004
[ Key-Id ]
* [ AVP ]
0*1 < MAC >
8.2.17 PANA-FirstAuth-End-Answer (PFEA)
PANA-FirstAuth-End-Answer (PFEA) is sent by the PaC to the PAA in
response to a PANA-FirstAuth-End-Request message.
PANA-FirstAuth-End-Answer ::= < PANA-Header: 9, REQ [SEP] [NAP] >
< Session-Id >
[ Key-Id ]
* [ AVP ]
0*1 < MAC >
8.2.18 PANA-Update-Request (PUR)
PANA-Update-Request (PUR) is sent by the PaC to the PAA.
PANA-Update-Request ::= < PANA-Header: 10, REQ >
< Session-Id >
< IP-Address >
* [ AVP ]
0*1 < MAC >
8.2.19 PANA-Update-Answer (PUA)
PANA-Update-Answer (PUA) is sent by the PAA to the PaC in response to
a PANA-Update-Request.
PANA-Update-Answer ::= < PANA-Header: 10 >
< Session-Id >
* [ AVP ]
0*1 < MAC >
8.3 AVPs in PANA
PANA defines several AVPs that are specific to the protocol. A
number of others AVPs are reused. These are specified in other
documents such as [RFC3588].
The following tables lists the AVPs used in this document, and
specifies in which PANA messages they MAY, or MAY NOT be present.
Forsberg, et al. Expires April 20, 2005 [Page 45]
Internet-Draft PANA October 2004
The table uses the following symbols:
0 The AVP MUST NOT be present in the message.
0+ Zero or more instances of the AVP MAY be present in the
message.
0-1 Zero or one instance of the AVP MAY be present in the message.
It is considered an error if there are more than one instance
of the AVP.
1 One instance of the AVP MUST be present in the message.
1+ At least one instance of the AVP MUST be present in the
message.
+-----------------------------------------+
| Message |
| Type |
+-----+-----+-----+-----+-----+-----+-----+
Attribute Name | PSR | PSA | PAR | PAN | PBR | PBA | PDI |
--------------------+-----+-----+-----+-----+-----+-----+-----+
Result-Code | 0 | 0 | 0 | 0 | 1 | 1 | 0 |
Session-Id | 0 | 0-1 | 1 | 1 | 1 | 1 | 0 |
Termination-Cause | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
EAP-Payload | 0-1 | 0-1 | 1 | 0-1 | 0-1 | 0 | 0 |
MAC | 0 | 0-1 | 0-1 | 0-1 | 0-1 | 0-1 | 0 |
Nonce | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
Device-Id | 0 | 0 | 0 | 0 | 0+ | 0-1 | 0 |
Cookie | 0-1 | 0-1 | 0 | 0 | 0 | 0 | 0 |
Protection-Cap. | 0-1 | 0 | 0 | 0 | 0-1 | 0 | 0 |
PPAC | 0-1 | 0 | 0 | 0 | 1 | 0-1 | 0 |
Session-Lifetime | 0 | 0 | 0 | 0 | 0-1 | 0 | 0 |
Failed-AVP | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
ISP-Information | 0+ | 0-1 | 0 | 0 | 0 | 0 | 0 |
NAP-Information | 0-1 | 0 | 0 | 0 | 0 | 0 | 0 |
Key-Id | 0 | 0 | 0 | 0 | 0-1 | 0-1 | 0 |
IP-Address | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
--------------------+-----+-----+-----+-----+-----+-----+-----+
Figure 11: AVP Occurrence Table (1/3)
Forsberg, et al. Expires April 20, 2005 [Page 46]
Internet-Draft PANA October 2004
+-------------------------------------+
| Message |
| Type |
+-----+-----+-----+-----+------+------+
Attribute Name | PPR | PPA | PTR | PTA | PFER | PFEA |
--------------------+-----+-----+-----+-----+------+------+
Result-Code | 0 | 0 | 0 | 0 | 1 | 0 |
Session-Id | 1 | 1 | 1 | 1 | 1 | 1 |
Termination-Cause | 0 | 0 | 1 | 0 | 0 | 0 |
EAP-Payload | 0 | 0 | 0 | 0 | 1 | 0 |
MAC | 0-1 | 0-1 | 0-1 | 0-1 | 0-1 | 0-1 |
Nonce | 0 | 0 | 0 | 0 | 0 | 0 |
Device-Id | 0 | 0 | 0 | 0 | 0 | 0 |
Cookie | 0 | 0 | 0 | 0 | 0 | 0 |
Protection-Cap. | 0 | 0 | 0 | 0 | 0 | 0 |
PPAC | 0 | 0 | 0 | 0 | 0 | 0 |
Session-Lifetime | 0 | 0 | 0 | 0 | 0 | 0 |
Failed-AVP | 0 | 0 | 0 | 0 | 0 | 0 |
ISP-Information | 0 | 0 | 0 | 0 | 0 | 0 |
NAP-Information | 0 | 0 | 0 | 0 | 0 | 0 |
Key-Id | 0 | 0 | 0 | 0 | 0-1 | 0-1 |
IP-Address | 0 | 0 | 0 | 0 | 0 | 0 |
--------------------+-----+-----+-----+-----+------+------+
Figure 12: AVP Occurrence Table (2/3)
Forsberg, et al. Expires April 20, 2005 [Page 47]
Internet-Draft PANA October 2004
+-------------------------------------+
| Message |
| Type |
+-----+-----+-----+-----+------+------+
Attribute Name | PUR | PUA | PER | PEA | PRAR | PRAA |
--------------------+-----+-----+-----+-----+------+------+
Result-Code | 0 | 0 | 1 | 0 | 0 | 0 |
Session-Id | 1 | 1 | 1 | 1 | 1 | 1 |
Termination-Cause | 0 | 0 | 0 | 0 | 0 | 0 |
EAP-Payload | 0 | 0 | 0 | 0 | 0 | 0 |
MAC | 0-1 | 0-1 | 0-1 | 0-1 | 0-1 | 0-1 |
Nonce | 0 | 0 | 0 | 0 | 0 | 0 |
Device-Id | 0 | 0 | 0 | 0 | 0 | 0 |
Cookie | 0 | 0 | 0 | 0 | 0 | 0 |
Protection-Cap. | 0 | 0 | 0 | 0 | 0 | 0 |
PPAC | 0 | 0 | 0 | 0 | 0 | 0 |
Session-Lifetime | 0 | 0 | 0 | 0 | 0 | 0 |
Failed-AVP | 0 | 0 | 1 | 0 | 0 | 0 |
ISP-Information | 0 | 0 | 0 | 0 | 0 | 0 |
NAP-Information | 0 | 0 | 0 | 0 | 0 | 0 |
Key-Id | 0 | 0 | 0 | 0 | 0 | 0 |
IP-Address | 1 | 0 | 0 | 0 | 0 | 0 |
--------------------+-----+-----+-----+-----+------+------+
Figure 13: AVP Occurrence Table (3/3)
8.3.1 MAC AVP
The first octet (8 bits) of the MAC (AVP Code 1) AVP data contains
the MAC algorithm type. Rest of the AVP data payload contains the
MAC encoded in network byte order. The 8-bit Algorithm name space is
managed by IANA [ianaweb]. The AVP length varies depending on the
used algorithm.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Algorithm | MAC...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Algorithm
1 HMAC-SHA1 (20 bytes)
Forsberg, et al. Expires April 20, 2005 [Page 48]
Internet-Draft PANA October 2004
MAC
The Message Authentication Code is encoded in network byte order.
8.3.2 Device-Id AVP
The Device-Id AVP (AVP Code 2) is of Address type [RFC3588]. IPv4
and IPv6 addresses are encoded as specified in [RFC3588]. The
content and format of data (including byte and bit ordering) for
link-layer addresses is expected to be specified in specific
documents that describe how IP operates over different link-layers.
For instance, [RFC2464]. Address families other than that are
defined for link-layer or IP addresses MUST NOT be used for this AVP.
8.3.3 Session-Id AVP
All messages pertaining to a specific PANA session MUST include a
Session-Id AVP (AVP Code 3) which carries a PAA-assigned fix value
throughout the lifetime of a session. When present, the Session-Id
SHOULD appear immediately following the PANA header.
The Session-Id MUST be globally and eternally unique, as it is meant
to identify a PANA Session without reference to any other
information, and may be needed to correlate historical authentication
information with accounting information. The PANA Session-Id AVP has
the same format as the Diameter Session-Id AVP [RFC3588].
8.3.4 Cookie AVP
The Cookie AVP (AVP Code 4) is of type OctetString. The data is
opaque and the exact content is outside the scope of this protocol.
8.3.5 Protection-Capability AVP
The Protection-Capability AVP (AVP Code 5) is of type Unsigned32.
The AVP data indicates the cryptographic data protection capability
supported by the EPs. Below is a list of specified data protection
capabilities:
0 L2_PROTECTION
1 IPSEC_PROTECTION
8.3.6 Termination-Cause AVP
The Termination-Cause AVP (AVP Code 6) is of type of type Enumerated,
and is used to indicate the reason why a session was terminated on
the access device. The AVP data is used as a collection of flags The
Forsberg, et al. Expires April 20, 2005 [Page 49]
Internet-Draft PANA October 2004
following Termination-Cause AVP defined in [RFC3588] are used for
PANA.
LOGOUT 1 (PaC -> PAA)
The client initiated a disconnect
ADMINISTRATIVE 4 (PAA -> PaC)
The client was not granted access, or was disconnected, due to
administrative reasons, such as the receipt of a
Abort-Session-Request message.
SESSION_TIMEOUT 8 (PAA -> PaC)
The session has timed out, and service has been terminated.
8.3.7 Result-Code AVP
The Result-Code AVP (AVP Code 7) is of type Unsigned32 and indicates
whether an EAP authentication was completed successfully or whether
an error occurred. Here are Result-Code AVP values taken from
[RFC3588] and adapted for PANA.
8.3.7.1 Authentication Results Codes
These result code values inform the PaC about the authentication and
authorization result. The authentication result and authorization
result can be different as described below, but only one result that
corresponds to the one detected first is returned.
PANA_SUCCESS 2001
Both the authentication and authorization processes are
successful.
PANA_AUTHENTICATION_REJECTED 4001
The authentication process failed. When this error is returned,
the authorization process also fails.
PANA_AUTHORIZATION_REJECTED 5003
The authorization process failed. This error could occur when
authorization is rejected by a AAA proxy or rejected locally by a
PAA, even if the authentication procedure succeeds.
Forsberg, et al. Expires April 20, 2005 [Page 50]
Internet-Draft PANA October 2004
8.3.7.2 Protocol Error Result Codes
Protocol error result code values.
PANA_MESSAGE_UNSUPPORTED 3001
Error code from PAA to PaC or from PaC to PAA. Message type not
recognized or supported.
PANA_UNABLE_TO_DELIVER 3002
Error code from PAA to PaC. PAA was unable to deliver the EAP
payload to the authentication server.
PANA_INVALID_HDR_BITS 3008
Error code from PAA to PaC or from PaC to PAA. A message was
received whose bits in the PANA header were either set to an
invalid combination, or to a value that is inconsistent with the
message type's definition.
PANA_INVALID_AVP_BITS 3009
Error code from PAA to PaC or from PaC to PAA. A message was
received that included an AVP whose flag bits are set to an
unrecognized value, or that is inconsistent with the AVP's
definition.
PANA_AVP_UNSUPPORTED 5001
Error code from PAA to PaC or from PaC to PAA. The received
message contained an AVP that is not recognized or supported and
was marked with the Mandatory bit. A PANA message with this error
MUST contain one or more Failed-AVP AVP containing the AVPs that
caused the failure.
PANA_UNKNOWN_SESSION_ID 5002
Error code from PAA to PaC or from PaC to PAA. The message
contained an unknown Session-Id. PAA MUST NOT send this error
result code value to PaC if PaC sent an unknown Session-Id in the
PANA-Start-Answer message (session resumption).
PANA_INVALID_AVP_VALUE 5004
Forsberg, et al. Expires April 20, 2005 [Page 51]
Internet-Draft PANA October 2004
Error code from PAA to PaC or from PaC to PAA. The message
contained an AVP with an invalid value in its data portion. A
PANA message indicating this error MUST include the offending AVPs
within a Failed-AVP AVP.
PANA_MISSING_AVP 5005
Error code from PAA to PaC or from PaC to PAA. The message did
not contain an AVP that is required by the message type
definition. If this value is sent in the Result-Code AVP, a
Failed-AVP AVP SHOULD be included in the message. The Failed-AVP
AVP MUST contain an example of the missing AVP complete with the
Vendor-Id if applicable. The value field of the missing AVP
should be of correct minimum length and contain zeroes.
PANA_RESOURCES_EXCEEDED 5006
Error code from PAA to PaC. A message was received that cannot be
authorized because the client has already expended allowed
resources. An example of this error condition is a client that is
restricted to one PANA session and attempts to establish a second
session.
PANA_CONTRADICTING_AVPS 5007
Error code from PAA to PaC. The PAA has detected AVPs in the
message that contradicted each other, and is not willing to
provide service to the client. One or more Failed-AVP AVPs MUST
be present, containing the AVPs that contradicted each other.
PANA_AVP_NOT_ALLOWED 5008
Error code from PAA to PaC or from PaC to PAA. A message was
received with an AVP that MUST NOT be present. The Failed-AVP AVP
MUST be included and contain a copy of the offending AVP.
PANA_AVP_OCCURS_TOO_MANY_TIMES 5009
Error code from PAA to PaC or from PaC to PAA. A message was
received that included an AVP that appeared more often than
permitted in the message definition. The Failed-AVP AVP MUST be
included and contain a copy of the first instance of the offending
AVP that exceeded the maximum number of occurrences.
PANA_UNSUPPORTED_VERSION 5011
Forsberg, et al. Expires April 20, 2005 [Page 52]
Internet-Draft PANA October 2004
Error code from PAA to PaC or from PaC to PAA. This error is
returned when a message was received, whose version number is
unsupported.
PANA_UNABLE_TO_COMPLY 5012
This error is returned when a request is rejected for unspecified
reasons. For example, when an EAP authentication fails at an EAP
pass-through authenticator without passing an EAP-Failure message
to the PAA, a Result-Code AVP with this error code is carried in
PANA-Error-Request message.
PANA_INVALID_AVP_LENGTH 5014
Error code from PAA to PaC or from PaC to PAA. The message
contained an AVP with an invalid length. The PANA-Error message
indicating this error MUST include the offending AVPs within a
Failed-AVP AVP.
PANA_INVALID_MESSAGE_LENGTH 5015
Error code from PAA to PaC or from PaC to PAA. This error is
returned when a message is received with an invalid message
length.
PANA_PROTECTION_CAPABILITY_UNSUPPORTED 5016
Error code from PaC to PAA. This error is returned when the PaC
receives a PANA-Bind-Request with a Protection-Capability AVP and
a valid MAC AVP but does not support the protection capability
specified in the Protection-Capability AVP.
PANA_PPAC_CAPABILITY_UNSUPPORTED 5017
Error code from PaC to PAA. This error is returned in a
PANA-Bind-Answer message when there is no match between the list
of PPAC methods offered by the PAA and the ones available on the
PaC.
PANA_INVALID_IP_ADDRESS 5018
Error code from PAA to PaC. This error is returned in a
PANA-Error-Request message when the IP-Address AVP in the received
PANA-Update-Request message is invalid (e.g., a non-unicast
address).
Forsberg, et al. Expires April 20, 2005 [Page 53]
Internet-Draft PANA October 2004
8.3.8 EAP-Payload AVP
The EAP-Payload AVP (AVP Code 8) is of type OctetString and is used
to encapsulate the actual EAP packet that is being exchanged between
the EAP peer and the EAP authenticator.
8.3.9 Session-Lifetime AVP
The Session-Lifetime AVP (AVP Code 9) data is of type Unsigned32. It
contains the number of seconds remaining before the current session
is considered expired.
8.3.10 Failed-AVP AVP
The Failed-AVP AVP (AVP Code 10) is of type Grouped and provides
debugging information in cases where a request is rejected or not
fully processed due to erroneous information in a specific AVP. The
format of the Failed-AVP AVP is defined in [RFC3588].
8.3.11 NAP-Information AVP
The NAP-Information AVP (AVP Code 11) is of type Grouped, and
contains zero or one Provider-Identifier AVP which carries the
identifier of the NAP and one Provider-Name AVP which carries the
name of the NAP. Its Data field has the following ABNF grammar:
NAP-Information ::= < AVP Header: 11 >
0*1 { Provider-Identifier }
{ Provider-Name }
* [ AVP ]
8.3.12 ISP-Information AVP
The ISP-Information AVP (AVP Code 12) is of type Grouped, and
contains zero or one Provider-Identifier AVP which carries the
identifier of the ISP and one Provider-Name AVP which carries the
name of the ISP. Its Data field has the following ABNF grammar:
ISP-Information ::= < AVP Header: 12 >
0*1 { Provider-Identifier }
{ Provider-Name }
* [ AVP ]
8.3.13 Provider-Identifier AVP
The Provider-Identifier AVP (AVP Code 13) is of type Unsigned32, and
Forsberg, et al. Expires April 20, 2005 [Page 54]
Internet-Draft PANA October 2004
contains an IANA assigned "SMI Network Management Private Enterprise
Codes" [ianaweb] value, encoded in network byte order.
8.3.14 Provider-Name AVP
The Provider-Name AVP (AVP Code 14) is of type UTF8String, and
contains the UTF8-encoded name of the provider.
8.3.15 Key-Id AVP
The Key-Id AVP (AVP Code 15) is of type Integer32, and contains an
AAA-Key identifier. The AAA-Key identifier is assigned by PAA and
MUST be unique within the PANA session.
8.3.16 Post-PANA-Address-Configuration (PPAC) AVP
The data field of PPAC AVP (AVP Code 16) is of type Unsigned32. The
AVP data is used to carry a set of flags which maps to various IP
address configuration methods. When sent by the PAA, the AVP MUST
have at least one of the flags set, and MAY have more than one set.
When sent by the PaC, only one of the flags MUST be set.
The format of the AVP data is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|N|D|A|T|I| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
PPAC Flags
N (No configuration)
The PaC does not have to (if sent by PAA) or will not (if sent
by PaC) configure a new IP address after PANA.
D (DHCP)
The PaC can (if sent by PAA) or will (if sent by PaC) use DHCP
[RFC2131][RFC3315] to configure a new IP address after PANA.
A (stateless autoconfiguration)
The PaC can/will use stateless IPv6 address autoconfiguration
[RFC2462] to configure a new IP address after PANA.
Forsberg, et al. Expires April 20, 2005 [Page 55]
Internet-Draft PANA October 2004
T (DHCP with IPsec tunnel mode)
The PaC can/will use [RFC3456] to configure a new IP address
after PANA.
I (IKEv2)
The PaC can/will use [I-D.ietf-ipsec-ikev2] to configure a new
IP address after PANA.
Reserved
These flag bits are reserved for future use, and MUST be set to
zero, and ignored by the receiver.
Unless the N-flag is set, the PaC MUST configure a new IP address
using one of the methods indicated by the other flags. Refer to
[I-D.ietf-pana-framework] for a detailed discussion on when these
methods can be used.
8.3.17 Nonce AVP
The Nonce AVP (AVP Code 17) is of type OctetString. The data
contains a randomly generated value in opaque format. The data
length MUST be between 8 and 256 bytes inclusive.
8.3.18 IP-Address AVP
The IP-Address (AVP Code 18) contains an IP address of n a PaC or
PAA. The payload format of the IP-Address AVP is the same as that of
the Device-Id AVP (see See Section 8.3.2). Address families for IPv4
or IPv6 MUST be used for this AVP. Address families for IPv4 or IPv6
MUST be used for this AVP.
Forsberg, et al. Expires April 20, 2005 [Page 56]
Internet-Draft PANA October 2004
9. PANA Protocol Message Retransmissions
The PANA protocol provides retransmissions for the PANA-PAA-Discover
and request messages.
The rule is that the sender of the request message retransmits the
request if the corresponding answer is not received in time. Answer
messages are sent as answers to the request messages, not based on a
timer.
PaC MUST retransmit PANA-PAA-Discover if a subsequent
PANA-Start-Request is not received in time. Even though a
PANA-Start-Request is received, PANA-PAA-Discover may still have to
be retransmitted. This is because a stateless PANA handshake
requires one time transmission of a PANA-Start-Request. PAA MUST NOT
start a timer and retransmit the request if it wants to avoid state
creation. If the received PANA-Start-Request included a Cookie AVP
(an indication of stateless handshake), PaC MUST retransmit
PANA-PAA-Discover until the first PANA-Auth-Request is received.
PANA retransmission timers are based on the model used in DHCPv6
[RFC3315]. Variables used here are also borrowed from this
specification. PANA is a request response like protocol. The
message exchange terminates when either the request sender
successfully receives the appropriate answer, or when the message
exchange is considered to have failed according to the retransmission
mechanism described below.
The retransmission behavior is controlled and described by the
following variables:
RT Retransmission timeout
IRT Initial retransmission time
MRC Maximum retransmission count
MRT Maximum retransmission time
MRD Maximum retransmission duration
RAND Randomization factor
With each message transmission or retransmission, the sender sets RT
according to the rules given below. If RT expires before the message
exchange terminates, the sender recomputes RT and retransmits the
message.
Forsberg, et al. Expires April 20, 2005 [Page 57]
Internet-Draft PANA October 2004
Each of the computations of a new RT include a randomization factor
(RAND), which is a random number chosen with a uniform distribution
between -0.1 and +0.1. The randomization factor is included to
minimize synchronization of messages.
The algorithm for choosing a random number does not need to be
cryptographically sound. The algorithm SHOULD produce a different
sequence of random numbers from each invocation.
RT for the first message transmission is based on IRT:
RT = IRT + RAND*IRT
RT for each subsequent message transmission is based on the previous
value of RT:
RT = 2*RTprev + RAND*RTprev
MRT specifies an upper bound on the value of RT (disregarding the
randomization added by the use of RAND). If MRT has a value of 0,
there is no upper limit on the value of RT. Otherwise:
if (RT > MRT)
RT = MRT + RAND*MRT
MRC specifies an upper bound on the number of times a sender may
retransmit a message. Unless MRC is zero, the message exchange fails
once the sender has transmitted the message MRC times.
MRD specifies an upper bound on the length of time a sender may
retransmit a message. Unless MRD is zero, the message exchange fails
once MRD seconds have elapsed since the client first transmitted the
message.
If both MRC and MRD are non-zero, the message exchange fails whenever
either of the conditions specified in the previous two paragraphs are
met.
If both MRC and MRD are zero, the client continues to transmit the
message until it receives a response.
9.1 Transmission and Retransmission Parameters
This section presents a table of values used to describe the message
retransmission behavior of PANA requests (REQ_*) and
PANA-PAA-Discover message (PDI_*). The table shows default values.
Parameter Default Description
Forsberg, et al. Expires April 20, 2005 [Page 58]
Internet-Draft PANA October 2004
------------------------------------------------
PDI_IRT 1 sec Initial PDI timeout.
PDI_MRT 120 secs Max PDI timeout value.
PDI_MRC 0 Configurable.
PDI_MRD 0 Configurable.
REQ_IRT 1 sec Initial Request timeout.
REQ_MRT 30 secs Max Request timeout value.
REQ_MRC 10 Max Request retry attempts.
REQ_MRD 0 Configurable.
So for example the first RT for the PBR message is calculated using
REQ_IRT as the IRT:
RT = REQ_IRT + RAND*REQ_IRT
Forsberg, et al. Expires April 20, 2005 [Page 59]
Internet-Draft PANA October 2004
10. IANA Considerations
This section provides guidance to the Internet Assigned Numbers
Authority (IANA) regarding registration of values related to the PANA
protocol, in accordance with BCP 26 [IANA]. The following policies
are used here with the meanings defined in BCP 26: "Private Use",
"First Come First Served", "Expert Review", "Specification Required",
"IETF Consensus", "Standards Action".
This section explains the criteria to be used by the IANA for
assignment of numbers within namespaces defined within this document.
For registration requests where a Designated Expert should be
consulted, the responsible IESG area director should appoint the
Designated Expert. For Designated Expert with Specification
Required, the request is posted to the PANA WG mailing list (or, if
it has been disbanded, a successor designated by the Area Director)
for comment and review, and MUST include a pointer to a public
specification. Before a period of 30 days has passed, the Designated
Expert will either approve or deny the registration request and
publish a notice of the decision to the PANA WG mailing list or its
successor. A denial notice must be justified by an explanation and,
in the cases where it is possible, concrete suggestions on how the
request can be modified so as to become acceptable.
10.1 PANA UDP Port Number
PANA uses one well-known UDP port number (Section 5.2, Section 4.1
and Section 7.1, which needs to be assigned by the IANA.
10.2 PANA Multicast Address
PANA uses one well-known IPv4 multicast address for which the scope
is limited to be link-local by setting the TTL field to 255, and one
well-known IPv6 link-local scoped multicast address (Section 4.1 and
Section 7.1), which need to be assigned by the IANA.
10.3 PANA Header
As defined in Section 7.2, the PANA header contains two fields that
requires IANA namespace management; the Message Type and Flags field.
10.3.1 Message Type
The Message Type namespace is used to identify PANA messages. Values
0-65,533 are for permanent, standard message types, allocated by IETF
Consensus [IANA]. This document defines the Message Types 1-10. See
Section 8.2.1 through Section 8.2.19 for the assignment of the
Forsberg, et al. Expires April 20, 2005 [Page 60]
Internet-Draft PANA October 2004
namespace in this specification.
The values 65,534 and 65,535 (hexadecimal values 0xfffe - 0xffff) are
reserved for experimental messages. As these codes are only for
experimental and testing purposes, no guarantee is made for
interoperability between communicating PaC and PAA using experimental
commands, as outlined in [IANA-EXP].
10.3.2 Flags
There are 16 bits in the Flags field of the PANA header. This
document assigns bit 0 ('R'equest), bit 1 ('S'eparate) and bit 2
('N'AP Authentication). The remaining bits MUST only be assigned via
a Standards Action [IANA].
10.4 AVP Header
As defined in Section 7.3, the AVP header contains three fields that
requires IANA namespace management; the AVP Code, AVP Flags and
Vendor-Id fields where only the AVP Code and AVP Flags create new
namespaces.
10.4.1 AVP Code
The AVP Code namespace is used to identify attributes. There are
multiple namespaces. Vendors can have their own AVP Codes namespace
which will be identified by their Vendor-ID (also known as
Enterprise-Number) and they control the assignments of their
vendor-specific AVP codes within their own namespace. The absence of
a Vendor-ID or a Vendor-ID value of zero (0) identifies the IETF IANA
controlled AVP Codes namespace. The AVP Codes and sometimes also
possible values in an AVP are controlled and maintained by IANA.
AVP Code 0 is not used. This document defines the AVP Codes 1-18.
See Section 8.3.1 through Section 8.3.18 for the assignment of the
namespace in this specification.
AVPs may be allocated following Designated Expert with Specification
Required [IANA]. Release of blocks of AVPs (more than 3 at a time
for a given purpose) should require IETF Consensus.
Note that PANA defines a mechanism for Vendor-Specific AVPs, where
the Vendor-Id field in the AVP header is set to a non-zero value.
Vendor-Specific AVPs codes are for Private Use and should be
encouraged instead of allocation of global attribute types, for
functions specific only to one vendor's implementation of PANA, where
no interoperability is deemed useful. Where a Vendor-Specific AVP is
implemented by more than one vendor, allocation of global AVPs should
Forsberg, et al. Expires April 20, 2005 [Page 61]
Internet-Draft PANA October 2004
be encouraged instead.
10.4.2 Flags
There are 16 bits in the AVP Flags field of the AVP header, defined
in Section 7.3. This document assigns bit 0 ('V'endor Specific) and
bit 1 ('M'andatory). The remaining bits should only be assigned via
a Standards Action .
10.5 AVP Values
Certain AVPs in PANA define a list of values with various meanings.
For attributes other than those specified in this section, adding
additional values to the list can be done on a First Come, First
Served basis by IANA [IANA].
10.5.1 Algorithm Values of MAC AVP
As defined in Section 8.3.1, the Algorithm field of MAC AVP (AVP Code
1) defines the value of 1 (one) for HMAC-SHA1.
All remaining values are available for assignment via IETF Consensus
[IANA].
10.5.2 Protection-Capability AVP Values
As defined in Section 8.3.5, the Protection-Capability AVP (AVP Code
5) defines the values 0 and 1.
All remaining values are available for assignment via a Standards
Action [IANA].
10.5.3 Termination-Cause AVP Values
As defined in Section 8.3.6, the Termination-Cause AVP (AVP Code 6)
defines the values 1, 4 and 8.
All remaining values are available for assignment via IETF Consensus
[IANA].
10.5.4 Result-Code AVP Values
As defined in Section 8.3.7.1 and Section 8.3.7.2 the Result-Code AVP
(AVP Code 7) defines the values 2001, 3001-3002, 3008-3009, 4001,
5001-5009 and 5011-5019.
All remaining values are available for assignment via IETF Consensus
[IANA].
Forsberg, et al. Expires April 20, 2005 [Page 62]
Internet-Draft PANA October 2004
10.5.5 Post-PANA-Address-Configuration AVP Values
As defined in Section 8.3.16, the Post-PANA-Address-Configuration AVP
(AVP Code 17) defines the bits 0 ('N': no configuration), 1 ('D':
DHCP), 2 ('A' stateless autoconfiguration), 3 ('T': DHCP with IPsec
tunnel mode) and 4 ('I': IKEv2).
All remaining values are available for assignment via a Standards
Action [IANA].
Forsberg, et al. Expires April 20, 2005 [Page 63]
Internet-Draft PANA October 2004
11. Security Considerations
The PANA protocol defines a UDP-based EAP encapsulation that runs
between two IP-enabled nodes on the same IP link. Various security
threats that are relevant to a protocol of this nature are outlined
in [I-D.ietf-pana-threats-eval]. Security considerations stemming
from the use of EAP and EAP methods are discussed in [RFC3748]. This
section provides a discussion on the security-related issues that are
related to PANA framework and protocol design.
An important element in assessing security of PANA design and
deployment in a network is the presence of lower-layer (physical and
link-layer) security. In the context of this document, lower-layers
are said to be secure if they can prevent eavesdropping and spoofing
of packets. Examples of such networks are physically-secured DSL
networks and 3GPP2 networks with crytographically-secured cdma2000
link-layer.
In these examples, the lower-layer security is enabled even before
running the first PANA-based authentication. In the absence of such
a pre-established secure channel, one needs to be created in
conjunction with PANA using a link-layer or network-layer
cryptographic mechanism (e.g., IPsec).
11.1 General Security Measures
PANA provides multiple mechanisms to secure a PANA session.
Since PaC and PAA are on the same IP link, a simple TTL check on the
received PANA messages prevents off-link attacks.
PANA messages carry sequence numbers, which are monotonically
incremented by 1 with every new request message. These numbers are
randomly initialized at the beginning of the session, and verified
against expected numbers upon receipt. A message whose sequence
number is different than the expected one is silently discarded. In
addition to accomplishing orderly delivery of EAP messages and
duplicate elimination, this scheme also helps prevent an adversary
spoof messages to disturb ongoing PANA and EAP sessions unless it can
also eavesdrop to synchronize on the expected sequence number.
The PANA framework defines EP which is ideally located on a network
device that can filter traffic from the PaCs before the traffic
enters the Internet. A set of filters can be used to discard
unauthorized packets, such as a PANA-Start-Request message that is
received from the segment of the access network where only PaCs are
supposed to be connected.
Forsberg, et al. Expires April 20, 2005 [Page 64]
Internet-Draft PANA October 2004
The protocol also provides authentication and integrity protection to
PANA messages when the used EAP method can generate cryptographic
session keys. A PANA SA is generated based on the AAA-Key exported
by the EAP method. This SA is used for generating per-packet MAC to
protect the PANA header and payload (including the complete EAP
message).
The cryptographic protection prevents an adversary from acting as a
man-in-the-middle, injecting messages, replaying messages and
modifying the content of the exchanged messages. Any packet that
fails to pass the MAC verification is silently discarded. The
earliest this protection can be enabled is when the very first
PANA-Bind-Request that signals a successful authentication is
generated. Starting with the PANA-Bind-Request and PANA-Bind-Answer,
any subsequent PANA message until the session gets torn down can be
cryptographically protected.
The PANA SA enables authenticated and integrity protected exchange of
the device ID information between the PaC and PAA. This ensures
there were no man-in-the-middle during the PANA authentication.
The lifetime of the PANA SA is bounded by the AAA-authorized session
lifetime with an additional tolerance period. Unless PANA state is
updated by executing another EAP authentication, the PANA SA is
removed when the current session expires.
The ability to use cryptographic protection within PANA is determined
by the used EAP method, which is generally dictated by the deployment
environment. Insecure lower-layers necessitate use of key-generating
EAP methods. In networks where lower-layers are already secured,
cryptographic protection of PANA messages is not necessary.
11.2 Discovery
The discovery and handshake phase is vulnerable to spoofing attacks
as these messages are not authenticated and integrity protected. In
order to prevent very basic denial-of service attacks an adversary
should not be able to cause state creation by sending discovery
messages to the PAA. This protection is achieved by using a
cookie-based scheme (similar to [RFC2522] which allows the responder
(PAA) to be stateless in the first round of message exchange. A
return-routability test does not provide additional protection as
PANA traffic is not routed but simply forwarded on-link. It is
difficult to prevent this threat entirely.
In networks where lower-layers are not secured prior to running PANA,
the capability discovery enabled through inclusion of
Protection-Capability and Post-PANA-Address-Configuration AVPs in a
Forsberg, et al. Expires April 20, 2005 [Page 65]
Internet-Draft PANA October 2004
PANA-Start-Request message is susceptible to spoofing leading to
denial-of service attacks. Therefore, usage of these AVPs during the
discovery and handshake phase in such insecure networks is NOT
RECOMMENDED. The same AVPs are delivered via an integrity-protected
PANA-Bind-Request upon successful authentication.
11.3 EAP Methods
Eavesdropping EAP packets might cause problems when the EAP method is
weak and enables dictionary or replay attacks or even allows an
adversary to learn the long-term password directly. Furthermore, if
the optional EAP Identity payload is used then it allows the
adversary to learn the identity of the PaC. In such a case a privacy
problem is prevalent.
To prevent these threats, [I-D.ietf-pana-framework] suggests using
proper EAP methods for particular environments. Depending on the
deployment environment an EAP authentication which supports user
identity confidentiality, protection against dictionary attacks and
session key establishment must be used. It is therefore the
responsibility of the network operators and users to choose a proper
EAP method.
11.4 Separate NAP and ISP Authentication
The PANA design allows running two separate EAP sessions for the same
PaC in a single authentication phase: one with the NAP, and one with
the ISP. The process of arriving at the resultant authorization,
which is a combination of the individual authorizations obtained from
respective service providers, is outside the scope of this protocol.
In the absence of lower-layer security, both authentications MUST be
able to generate a AAA-Key, leading to generation of a PANA SA. The
resultant PANA SA cryptographically binds the two AAA-Keys together,
hence it prevents man-in-the-middle attacks.
11.5 Cryptographic Keys
When the EAP method exports a AAA-Key, this key is used to produce a
PANA SA with PANA_MAC_KEY with a distinct key ID. The PANA_MAC_KEY
is unique to the PANA session, and takes PANA-based nonce values into
computation to cryptographically separate itself from the AAA-Key.
The PANA_MAC_KEY is solely used for authentication and integrity
protection of the PANA messages within the designated session.
Two AAA-Keys may be generated as a result of separate NAP and ISP
authentication. In that case, the AAA-Key used with the PANA SA is
the combination of both keys.
Forsberg, et al. Expires April 20, 2005 [Page 66]
Internet-Draft PANA October 2004
The PANA SA lifetime is bounded by the AAA-Key lifetime. Another
execution of EAP method yields in a new AAA-Key, and updates the PANA
SA, PANA_MAC_KEY and key ID.
Upon PaC's movement to a another PAA (new PAA) and request to perform
a context transfer based optimization, the current PAA computes a
AAA-Key-int based on the AAA-Key, ID of new PAA, and the session ID.
This AAA-Key-int is delivered to the new PAA, and used in the
computation of AAA-Key-new, which further takes a pair of nonce
values into account. After this point on, the AAA-Key-new becomes
the AAA-Key between the PaC and the new PAA.
When link-layer or network-layer ciphering [I-D.ietf-pana-ipsec] is
enabled as a result of successful PANA authentication, a separate
master key is generated based on the AAA-Key, session ID, key ID, and
EP ID.
The lifetime of this key is bounded by the lifetime of the PANA SA.
This key may be used with a secure association protocol
[I-D.ietf-ipsec-ikev2] to produce further cipher-specific and
transient keys.
11.6 Per-packet Ciphering
Networks that are not secured at the lower-layers prior to running
PANA can rely on enabling per-packet data traffic ciphering upon
successful PANA session establishment. The PANA framework allows
generation of a master key from AAA-Key for using with a per-packet
protection mechanism, such as link-layer or IPsec-based ciphering
[I-D.ietf-pana-ipsec]. In case the master key is not readily useful
to the ciphering mechanism, an additional secure association protocol
[I-D.ietf-ipsec-ikev2] may be needed to produce the required keying
material. These mechanisms ultimately establish a cryptographic
binding between the data traffic generated by and for a client and
the authenticated identity of the client. Data traffic must be
minimally data origin authenticated, replay and integrity protected,
and optionally encrypted.
11.7 PAA-to-EP Communication
The PANA framework allows separation of PAA from EP(s). SNMPv3
[I-D.ietf-pana-snmp] is used between the the PAA and EP for
provisioning authorized PaC information on the EP. This exchange
MUST be always physically or cryptographically protected for
authentication, integrity and replay protection. It MUST also be
privacy-protected when per-PaC master key for per-packet ciphering is
transmitted to the EP.
Forsberg, et al. Expires April 20, 2005 [Page 67]
Internet-Draft PANA October 2004
The per-packet ciphering master key MUST be unique to the PaC and EP
pair. The session ID and EP's device ID are taken into computation
for achieving this effect [I-D.ietf-pana-ipsec]. Compromise of an EP
does not automatically lead to compromise of another EP or the PAA.
11.8 Livenes Test
A PANA session is associated with a session lifetime. The session is
terminated unless it is refreshed by a new round of EAP
authentication before it expires. Therefore, at the latest a
disconnected client can be detected when its lifetime expires. A
disconnect may also be detected earlier by using PANA ping messages.
A request message can be generated by either PaC or PAA at any time
and the peer must respond with an answer message. A successful
round-trip of this exchange is a simple verification that the peer is
alive. This test can be engaged when there is a possibility that the
peer might have disconnected (e.g., after discontinuation of data
traffic). Periodic use of this exchange as a keep-alive requires
additional care as it might result in congestion and hence false
alarms. This exchange is cryptographically protected when a PANA SA
is available in order to prevent threats associated with the abuse of
this functionality.
11.9 Mobility Optimization
The mobility optimization described in Section 4.12 involves the
previous PAA providing a AAA-Key to the current PAA of the PaC.
There are security risks stemming from potential compromise of PAAs.
Compromise of the current PAA does not yield compromise of the
previous PAA, as AAA-Key cannot be computed from a compromised
AAA-Key-new. But a compromised previous PAA along with the
intercepted nonce values on the current link leads to the compromise
of AAA-Key-new. Operators should be aware of the potential risk of
using this optimization. An operator can reduce the risk exposure by
forcing the PaC to perform an EAP-based authentication immediately
after the PaC gains access to new link via the optimized PANA
execution.
11.10 Updating PaC's IP Address
Even though the IP-Address AVP in a PANA-Update-Request can be
cryptographically protected by the MAC AVP, there is not way to prove
the ownership of the IP address presented by the PaC. Hence an
authorized PaC can launch a redirect attack by spoofing a victim's IP
address.
Forsberg, et al. Expires April 20, 2005 [Page 68]
Internet-Draft PANA October 2004
11.11 Early Termination of a Session
The PANA protocol supports the ability for both the PaC and the PAA
to transmit a tear-down message before the session lifetime expires.
This message causes state removal, a stop of the accounting procedure
and removes the installed per-PaC state on the EP(s). This message
is cryptographically protected when PANA SA is present.
Forsberg, et al. Expires April 20, 2005 [Page 69]
Internet-Draft PANA October 2004
12. Acknowledgments
We would like to thank Jari Arkko, Mohan Parthasarathy, Julien
Bournelle, Rafael Marin Lopez, Pasi Eronen, Randy Turner, Erik
Nordmark and all members of the PANA working group for their valuable
comments to this document.
Forsberg, et al. Expires April 20, 2005 [Page 70]
Internet-Draft PANA October 2004
13. References
13.1 Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC
2131, March 1997.
[RFC2988] Paxson, V. and M. Allman, "Computing TCP's Retransmission
Timer", RFC 2988, November 2000.
[RFC2234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997.
[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G. and J.
Arkko, "Diameter Base Protocol", RFC 3588, September 2003.
[RFC2462] Thomson, S. and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet
Networks", RFC 2464, December 1998.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C. and
M. Carney, "Dynamic Host Configuration Protocol for IPv6
(DHCPv6)", RFC 3315, July 2003.
[RFC3456] Patel, B., Aboba, B., Kelly, S. and V. Gupta, "Dynamic
Host Configuration Protocol (DHCPv4) Configuration of
IPsec Tunnel Mode", RFC 3456, January 2003.
[RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J. and H.
Levkowetz, "Extensible Authentication Protocol (EAP)", RFC
3748, June 2004.
[I-D.ietf-eap-keying]
Aboba, B., "Extensible Authentication Protocol (EAP) Key
Management Framework", draft-ietf-eap-keying-03 (work in
progress), July 2004.
[IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.
Forsberg, et al. Expires April 20, 2005 [Page 71]
Internet-Draft PANA October 2004
13.2 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-09 (work in progress), August
2004.
[RFC2522] Karn, P. and W. Simpson, "Photuris: Session-Key Management
Protocol", RFC 2522, March 1999.
[I-D.ietf-pana-threats-eval]
Parthasarathy, M., "Protocol for Carrying Authentication
and Network Access Threat Analysis and Security
Requirements", draft-ietf-pana-threats-eval-07 (work in
progress), August 2004.
[I-D.ietf-pana-ipsec]
Parthasarathy, M., "PANA enabling IPsec based Access
Control", draft-ietf-pana-ipsec-04 (work in progress),
September 2004.
[I-D.ietf-pana-framework]
Jayaraman, P., "PANA Framework",
draft-ietf-pana-framework-02 (work in progress), September
2004.
[I-D.ietf-pana-snmp]
Mghazli, Y., Ohba, Y. and J. Bournelle, "SNMP usage for
PAA-2-EP interface", draft-ietf-pana-snmp-01 (work in
progress), July 2004.
[I-D.irtf-aaaarch-handoff]
Arbaugh, W. and B. Aboba, "Experimental Handoff Extension
to RADIUS", draft-irtf-aaaarch-handoff-04 (work in
progress), November 2003.
[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-05 (work in progress),
September 2004.
[I-D.ietf-seamoby-ctp]
Loughney, J., "Context Transfer Protocol",
draft-ietf-seamoby-ctp-11 (work in progress), August 2004.
Forsberg, et al. Expires April 20, 2005 [Page 72]
Internet-Draft PANA October 2004
[I-D.ietf-ipsec-ikev2]
Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
draft-ietf-ipsec-ikev2-17 (work in progress), October
2004.
[ianaweb] IANA, "Number assignment", http://www.iana.org.
[IANA-EXP]
Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004.
Authors' Addresses
Dan Forsberg
Nokia Research Center
P.O. Box 407
FIN-00045 NOKIA GROUP
Finland
Phone: +358 50 4839470
EMail: dan.forsberg@nokia.com
Yoshihiro Ohba
Toshiba America Research, Inc.
1 Telcordia Drive
Piscataway, NJ 08854
USA
Phone: +1 732 699 5305
EMail: yohba@tari.toshiba.com
Basavaraj Patil
Nokia
6000 Connection Dr.
Irving, TX 75039
USA
Phone: +1 972-894-6709
EMail: Basavaraj.Patil@nokia.com
Forsberg, et al. Expires April 20, 2005 [Page 73]
Internet-Draft PANA October 2004
Hannes Tschofenig
Siemens Corporate Technology
Otto-Hahn-Ring 6
81739 Munich
Germany
EMail: Hannes.Tschofenig@siemens.com
Alper E. Yegin
Samsung Advanced Institute of Technology
75 West Plumeria Drive
San Jose, CA 95134
USA
Phone: +1 408 544 5656
EMail: alper.yegin@samsung.com
Forsberg, et al. Expires April 20, 2005 [Page 74]
Internet-Draft PANA October 2004
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Disclaimer of Validity
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Forsberg, et al. Expires April 20, 2005 [Page 75]
