draft-arkko-pppext-eap-aka-08.txt		draft-arkko-pppext-eap-aka-09.txt
J. Arkko		J. Arkko
Internet Draft Ericsson		Internet Draft Ericsson
Document: draft-arkko-pppext-eap-aka-08.txt H. Haverinen		Document: draft-arkko-pppext-eap-aka-09.txt H. Haverinen
Expires: June 2003 Nokia		Expires: July 2003 Nokia
January 2003		February 2003
EAP AKA Authentication		EAP AKA Authentication
Status of this Memo		Status of this Memo
This document is an Internet-Draft and is subject to all provisions		This document is an Internet-Draft and is subject to all provisions
of Section 10 of RFC2026.		of Section 10 of RFC2026.
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Status of this Memo................................................1		Status of this Memo................................................1
Abstract...........................................................1		Abstract...........................................................1
1. Introduction and Motivation.....................................2		1. Introduction and Motivation.....................................2
2. Terms and Conventions Used in This Document.....................4		2. Terms and Conventions Used in This Document.....................4
3. Protocol Overview...............................................6		3. Protocol Overview...............................................6
4. Identity Management............................................10		4. Identity Management............................................10
4.1. User Identity in EAP-Response/Identity.......................10		4.1. User Identity in EAP-Response/Identity.......................10
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4.2. Obtaining Subscriber Identity via EAP AKA Messages...........12		4.2. Obtaining Subscriber Identity via EAP AKA Messages...........12
4.3. Identity Privacy Support.....................................14		4.3. Identity Privacy Support.....................................15
5. Re-authentication..............................................19		5. Re-authentication..............................................20
6. Message Format.................................................25		6. Message Format.................................................26
7. Message Authentication and Encryption..........................26		7. Message Authentication and Encryption..........................27
7.1. AT_MAC Attribute.............................................26		7.1. AT_MAC Attribute.............................................27
7.2. AT_IV, AT_ENCR_DATA and AT_PADDING Attributes................27		7.2. AT_IV, AT_ENCR_DATA and AT_PADDING Attributes................28
8. Messages.......................................................28		8. Messages.......................................................29
8.1. EAP-Request/AKA-Challenge....................................28		8.1. EAP-Request/AKA-Challenge....................................29
8.2. EAP-Response/AKA-Challenge...................................32		8.2. EAP-Response/AKA-Challenge...................................33
8.3. EAP-Response/AKA-Authentication-Reject.......................33		8.3. EAP-Response/AKA-Authentication-Reject.......................34
8.4. EAP-Response/AKA-Synchronization-Failure.....................34		8.4. EAP-Response/AKA-Synchronization-Failure.....................35
8.5. EAP-Request/AKA-Identity.....................................35		8.5. EAP-Request/AKA-Identity.....................................36
8.6. EAP-Response/AKA-Identity....................................36		8.6. EAP-Response/AKA-Identity....................................37
8.7. EAP-Request/AKA-Reauthentication.............................37		8.7. EAP-Request/AKA-Reauthentication.............................38
8.8. EAP-Response/AKA-Reauthentication............................40		8.8. EAP-Response/AKA-Reauthentication............................41
8.9. EAP/AKA Notifications........................................42		8.9. EAP/AKA Notifications........................................43
9. Error Cases....................................................45		9. Error Cases....................................................46
10. Key Derivation................................................45		10. Key Derivation................................................46
11. IANA and Protocol Numbering Considerations....................47		11. IANA and Protocol Numbering Considerations....................48
12. Security Considerations.......................................48		12. Security Considerations.......................................49
12.1. Identity Protection.........................................48		12.1. Identity Protection.........................................49
12.2. Mutual Authentication.......................................49		12.2. Mutual Authentication.......................................50
12.3. Key Derivation..............................................49		12.3. Key Derivation..............................................50
12.4. Brute-Force and Dictionary Attacks..........................49		12.4. Brute-Force and Dictionary Attacks..........................50
12.5. Integrity Protection, Replay Protection and Confidentiality.49		12.5. Integrity Protection, Replay Protection and Confidentiality.50
12.6. Negotiation Attacks.........................................50		12.6. Negotiation Attacks.........................................51
12.7. Fast Reconnect..............................................50		12.7. Fast Reconnect..............................................51
12.8. Acknowledged Result Indications.............................50		12.8. Acknowledged Result Indications.............................51
12.9. Man-in-the-middle Attacks...................................50		12.9. Man-in-the-middle Attacks...................................51
12.10. Generating Random Numbers..................................51		12.10. Generating Random Numbers..................................52
13. Security Claims...............................................51		13. Security Claims...............................................52
14. Intellectual Property Right Notices...........................51		14. Intellectual Property Right Notices...........................52
Acknowledgements and Contributions................................51		Acknowledgements and Contributions................................53
Authors' Addresses................................................52		Authors' Addresses................................................53
Annex A. Pseudo-Random Number Generator...........................54		Annex A. Pseudo-Random Number Generator...........................54
1. Introduction and Motivation		1. Introduction and Motivation
This document specifies an Extensible Authentication Protocol (EAP)		This document specifies an Extensible Authentication Protocol (EAP)
mechanism for authentication and session key distribution using the		mechanism for authentication and session key distribution using the
UMTS AKA authentication mechanism [1].UMTS is a global third		UMTS AKA authentication mechanism [1].UMTS is a global third
generation mobile network standard.		generation mobile network standard.
AKA is based on challenge-response mechanisms and symmetric		AKA is based on challenge-response mechanisms and symmetric
cryptography. AKA typically runs in a UMTS Subscriber Identity		cryptography. AKA typically runs in a UMTS Subscriber Identity
Module (USIM). Compared to the GSM mechanism, UMTS AKA provides		Module (USIM). Compared to the GSM mechanism, UMTS AKA provides
substantially longer key lengths and mutual authentication.		substantially longer key lengths and mutual authentication.
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The introduction of AKA inside EAP allows several new applications.		The introduction of AKA inside EAP allows several new applications.
These include the following:		These include the following:
- The use of the AKA also as a secure PPP authentication method in		- The use of the AKA also as a secure PPP authentication method in
devices that already contain an USIM.		devices that already contain an USIM.
- The use of the third generation mobile network authentication		- The use of the third generation mobile network authentication
infrastructure in the context of wireless LANs and IEEE 802.1x		infrastructure in the context of wireless LANs and IEEE 802.1x
technology through EAP over Wireless [2, 3].		technology through EAP over Wireless [2, 3].
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values AUTN, RES, IK, CK and AUTS are calculated, see reference [1].		values AUTN, RES, IK, CK and AUTS are calculated, see reference [1].
It is also possible that the home environment delegates the actual		It is also possible that the home environment delegates the actual
authentication task to an intermediate node. In this case the		authentication task to an intermediate node. In this case the
authentication vector or parts of it are delivered to the		authentication vector or parts of it are delivered to the
intermediate node, enabling it to perform the comparison between RES		intermediate node, enabling it to perform the comparison between RES
and XRES, and possibly also use CK and IK. Such delivery MUST be		and XRES, and possibly also use CK and IK. Such delivery MUST be
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done in a secure manner. In EAP AKA, the EAP server node is such an		done in a secure manner. In EAP AKA, the EAP server node is such an
intermediate node.		intermediate node.
In the third generation mobile networks, AKA is used both for radio		In the third generation mobile networks, AKA is used both for radio
network authentication and IP multimedia service authentication		network authentication and IP multimedia service authentication
purposes. Different user identities and formats are used for these;		purposes. Different user identities and formats are used for these;
the radio network uses the International Mobile Subscriber		the radio network uses the International Mobile Subscriber
Identifier (IMSI), whereas the IP multimedia service uses the		Identifier (IMSI), whereas the IP multimedia service uses the
Network Access Identifier (NAI) [4].		Network Access Identifier (NAI) [4].
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Extensible Authentication Protocol [5].		Extensible Authentication Protocol [5].
EAP server		EAP server
The network element that terminates the EAP protocol. Typically,		The network element that terminates the EAP protocol. Typically,
the EAP server functionality is implemented in a AAA server.		the EAP server functionality is implemented in a AAA server.
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GSM		GSM
Global System for Mobile communications.		Global System for Mobile communications.
NAI		NAI
Network Access Identifier [4].		Network Access Identifier [4].
AUTN		AUTN
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UMTS Subscriber Identity Module. USIM is an application that is		UMTS Subscriber Identity Module. USIM is an application that is
resident e.g. on smart cards distributed by UMTS operators.		resident e.g. on smart cards distributed by UMTS operators.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC 2119 [6]		this document are to be interpreted as described in RFC 2119 [6]
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3. Protocol Overview		3. Protocol Overview
In this document, the term EAP Server refers to the network element		In this document, the term EAP Server refers to the network element
that terminates the EAP protocol. Usually the EAP server is separate		that terminates the EAP protocol. Usually the EAP server is separate
from the authenticator device, which is the network element closest		from the authenticator device, which is the network element closest
to the client, such as a Network Access Server (NAS) or an IEEE		to the client, such as a Network Access Server (NAS) or an IEEE
802.1X bridge. Alternatively, the EAP server functionality may be		802.1X bridge. Alternatively, the EAP server functionality may be
co-located in the authenticator although typically, the EAP server		co-located in the authenticator although typically, the EAP server
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The client runs the AKA algorithm (perhaps inside an USIM) and		The client runs the AKA algorithm (perhaps inside an USIM) and
verifies the AUTN. If this is successful, the client is talking to a		verifies the AUTN. If this is successful, the client is talking to a
legitimate EAP server and proceeds to send the EAP-Response/AKA-		legitimate EAP server and proceeds to send the EAP-Response/AKA-
Challenge. This message contains a result parameter that allows the		Challenge. This message contains a result parameter that allows the
EAP server in turn to authenticate the client, and the AT_MAC		EAP server in turn to authenticate the client, and the AT_MAC
attribute to integrity protect the EAP message.		attribute to integrity protect the EAP message.
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Client Authenticator		Client Authenticator
| |		| |
| EAP-Request/Identity |		| EAP-Request/Identity |
|<------------------------------------------------------|		|<------------------------------------------------------|
| |		| |
| EAP-Response/Identity |		| EAP-Response/Identity |
| (Includes user's NAI) |		| (Includes user's NAI) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
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The second message flow shows how the EAP server rejects the Client		The second message flow shows how the EAP server rejects the Client
due to a failed authentication. The same flow is also used in the		due to a failed authentication. The same flow is also used in the
GSM compatible mode, except that the AT_AUTN attribute and AT_MAC		GSM compatible mode, except that the AT_AUTN attribute and AT_MAC
attribute are not used in the messages.		attribute are not used in the messages.
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Client Authenticator		Client Authenticator
| |		| |
| EAP-Request/Identity |		| EAP-Request/Identity |
|<------------------------------------------------------|		|<------------------------------------------------------|
| |		| |
| EAP-Response/Identity |		| EAP-Response/Identity |
| (Includes user's NAI) |		| (Includes user's NAI) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
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error statistics as AKA in general produces in UMTS. Please note		error statistics as AKA in general produces in UMTS. Please note
that this behavior is different from other EAP/AKA error cases, such		that this behavior is different from other EAP/AKA error cases, such
as when encountering an incorrect AT_MAC attribute, the client		as when encountering an incorrect AT_MAC attribute, the client
silently discards the EAP/AKA message.		silently discards the EAP/AKA message.
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Client Authenticator		Client Authenticator
| |		| |
| EAP-Request/Identity |		| EAP-Request/Identity |
|<------------------------------------------------------|		|<------------------------------------------------------|
| |		| |
| EAP-Response/Identity |		| EAP-Response/Identity |
| (Includes user's NAI) |		| (Includes user's NAI) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
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The AKA uses shared secrets between the Client and the Client's home		The AKA uses shared secrets between the Client and the Client's home
operator together with a sequence number to actually perform an		operator together with a sequence number to actually perform an
authentication. In certain circumstances it is possible for the		authentication. In certain circumstances it is possible for the
sequence numbers to get out of sequence. Here's what happens then:		sequence numbers to get out of sequence. Here's what happens then:
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Client Authenticator		Client Authenticator
| |		| |
| EAP-Request/Identity |		| EAP-Request/Identity |
|<------------------------------------------------------|		|<------------------------------------------------------|
| |		| |
| EAP-Response/Identity |		| EAP-Response/Identity |
| (Includes user's NAI) |		| (Includes user's NAI) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
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support.		support.
4.1. User Identity in EAP-Response/Identity		4.1. User Identity in EAP-Response/Identity
In the beginning of an EAP authentication, the Authenticator issues		In the beginning of an EAP authentication, the Authenticator issues
the EAP-Request/Identity packet to the client. The client responds		the EAP-Request/Identity packet to the client. The client responds
with EAP-Response/Identity, which contains the user's identity. The		with EAP-Response/Identity, which contains the user's identity. The
formats of these packets are specified in [5].		formats of these packets are specified in [5].
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UMTS subscribers are identified with the International Mobile		UMTS subscribers are identified with the International Mobile
Subscriber Identity (IMSI) [7]. The IMSI is composed of a three		Subscriber Identity (IMSI) [7]. The IMSI is composed of a three
digit Mobile Country Code (MCC), a two or three digit Mobile Network		digit Mobile Country Code (MCC), a two or three digit Mobile Network
Code (MNC) and a not more than 10 digit Mobile Subscriber		Code (MNC) and a not more than 10 digit Mobile Subscriber
Identification Number (MSIN). In other words, the IMSI is a string		Identification Number (MSIN). In other words, the IMSI is a string
of not more than 15 digits. MCC and MNC uniquely identify the		of not more than 15 digits. MCC and MNC uniquely identify the
operator.		operator.
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case, the client implementation MUST NOT append any leading		case, the client implementation MUST NOT append any leading
characters to the username.		characters to the username.
When the optional identity privacy support is used on full		When the optional identity privacy support is used on full
authentication, the client MAY use the pseudonym received upon the		authentication, the client MAY use the pseudonym received upon the
previous full authentication sequence as the username portion of the		previous full authentication sequence as the username portion of the
NAI, as specified in Section 4.3. The client MUST NOT modify the		NAI, as specified in Section 4.3. The client MUST NOT modify the
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pseudonym received in AT_NEXT_PSEUDONYM. For example, the client		pseudonym received in AT_NEXT_PSEUDONYM. For example, the client
MUST NOT append any leading characters in the pseudonym.		MUST NOT append any leading characters in the pseudonym.
On re-authentication, the client uses the re-authentication identity		On re-authentication, the client uses the re-authentication identity
received upon the previous authentication sequence as the NAI. A new		received upon the previous authentication sequence as the NAI. A new
re-authentication identity may be delivered as part of both full		re-authentication identity may be delivered as part of both full
authentication and re-authentication. The client MUST NOT modify the		authentication and re-authentication. The client MUST NOT modify the
re-authentication identity received in AT_NEXT_REAUTH_ID but the		re-authentication identity received in AT_NEXT_REAUTH_ID but the
client must use the re-authentication identity as it is. For		client must use the re-authentication identity as it is. For
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It may be useful to obtain the identity of the subscriber through		It may be useful to obtain the identity of the subscriber through
means other than EAP Request/Identity. This can eliminate the need		means other than EAP Request/Identity. This can eliminate the need
for an identity request when using EAP method negotiation. If this		for an identity request when using EAP method negotiation. If this
was not possible then it might not be possible to negotiate EAP/AKA		was not possible then it might not be possible to negotiate EAP/AKA
as the second method since not all EAP implementations support		as the second method since not all EAP implementations support
multiple EAP Identity requests..		multiple EAP Identity requests..
If the EAP server has not received any identity (permanent identity,		If the EAP server has not received any identity (permanent identity,
pseudonym or re-authentication identity) from the client when		pseudonym or re-authentication identity) from the client when
sending the first EAP/AKA request, then the EAP server may issue the		sending the first EAP/AKA request, then the EAP server SHOULD issue
EAP-Request/AKA-Identity packet and includes the AT_ANY_ID_REQ		the EAP-Request/AKA-Identity packet and includes the AT_ANY_ID_REQ
attribute (specified in Section 8.5). This attribute does not		attribute (specified in Section 8.5). This attribute does not
contain any data.		contain any data.
		If the EAP server has received an EAP-Response/Identity packet but
		the contents do not appear to be a valid permanent identity,
		pseudonym or a re-authentication identity, the EAP server SHOULD
		issue an EAP-Request/AKA-Identity packet with the AT_ANY_ID_REQ
		attribute.
		In some environments the intermediate entities or software layers in
		the client may modify the identity string in the EAP-
		Response/Identity packet. For example, some EAP layer
		implementations may cache the identity string from the first
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		authentication and do not obtain a new identity string from the EAP
		method implementation on subsequent authentication exchanges.
		Because the identity string is used in key derivation, such
		modifications will result in failed authentication unless the EAP
		server uses the AT_ANY_ID_REQ attribute to obtain an unmodified copy
		of the identity string. Therefore, in cases when there is a
		possibility that an intermediate element or software layer may
		modify the EAP-Response/Identity packet, the EAP server SHOULD
		always use the EAP-Request/AKA-Identity packet with the
		AT_ANY_ID_REQ attribute, even if the identity received in EAP-
		Response/Identity was valid.
The AT_ANY_ID_REQ attribute requests the client to include the		The AT_ANY_ID_REQ attribute requests the client to include the
AT_IDENTITY attribute (specified in Section 8.6) in the EAP-		AT_IDENTITY attribute (specified in Section 8.6) in the EAP-
Response/AKA-Identity packet. The identity format in the AT_IDENTITY		Response/AKA-Identity packet. The identity format in the AT_IDENTITY
attribute is the same as in the Type-Data field of the EAP-		attribute is the same as in the Type-Data field of the EAP-
Response/Identity packet. The AT_IDENTITY attribute contains a		Response/Identity packet. The AT_IDENTITY attribute contains a
permanent identity, a pseudonym identity or a re-authentication		permanent identity, a pseudonym identity or a re-authentication
identity. If the server does not support re-authentication, it uses		identity. If the server does not support re-authentication, it uses
the AT_FULLAUTH_ID_REQ attribute instead of the AT_ANY_ID_REQ		the AT_FULLAUTH_ID_REQ attribute instead of the AT_ANY_ID_REQ
attribute to directly request for a full authentication identity		attribute to directly request for a full authentication identity
(either the permanent identity or a pseudonym identity). If the		(either the permanent identity or a pseudonym identity). If the
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server uses the AT_FULLAUTH_ID_REQ attribute, the client MUST NOT		server uses the AT_FULLAUTH_ID_REQ attribute, the client MUST NOT
use a re-authentication identity in the AT_IDENTITY attribute.		use a re-authentication identity in the AT_IDENTITY attribute.
The use of pseudonyms for anonymity is specified in Section 4.3. The		The use of pseudonyms for anonymity is specified in Section 4.3. The
use of re-authentication identities is specified in Section 5.		use of re-authentication identities is specified in Section 5.
The full authentication case is illustrated in the figure below. In		The full authentication case is illustrated in the figure below. In
this case, AT_IDENTITY contains either the permanent identity or a		this case, AT_IDENTITY contains either the permanent identity or a
pseudonym identity. The same sequence is also used in case the		pseudonym identity. The same sequence is also used in case the
server uses the AT_FULLAUTH_ID_REQ in EAP-Request/AKA-Identity		server uses the AT_FULLAUTH_ID_REQ in EAP-Request/AKA-Identity
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| |		| |
| |		| |
| EAP-Response/AKA-Identity |		| EAP-Response/AKA-Identity |
| (AT_IDENTITY) |		| (AT_IDENTITY) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
If the client wants to perform full authentication, it includes the		If the client wants to perform full authentication, it includes the
permanent identity or a pseudonym identity in the AT_IDENTITY		permanent identity or a pseudonym identity in the AT_IDENTITY
attribute. The client may use these identities in response to either		attribute. The client may use these identities in response to either
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AT_ANY_ID_REQ or AT_FULLAUTH_ID_REQ. If the server uses the		AT_ANY_ID_REQ or AT_FULLAUTH_ID_REQ. If the server uses the
AT_ANY_ID_REQ and the client wants to perform re-authentication,		AT_ANY_ID_REQ and the client wants to perform re-authentication,
then the client includes a re-authentication identity in the		then the client includes a re-authentication identity in the
AT_IDENTITY attribute.		AT_IDENTITY attribute.
If the client uses its full authentication identity and the		If the client uses its full authentication identity and the
AT_IDENTITY attribute contains a valid permanent identity or a valid		AT_IDENTITY attribute contains a valid permanent identity or a valid
pseudonym identity that the EAP server is able to decode to the		pseudonym identity that the EAP server is able to decode to the
permanent identity, then the full authentication sequence proceeds		permanent identity, then the full authentication sequence proceeds
as usual with the EAP Server issuing the EAP-Request/AKA-Challenge		as usual with the EAP Server issuing the EAP-Request/AKA-Challenge
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re-authentication identity and the server agrees on using re-		re-authentication identity and the server agrees on using re-
authentication, then the server proceeds with the re-authentication		authentication, then the server proceeds with the re-authentication
sequence and issues the EAP-Request/AKA-Reauthentication packet, as		sequence and issues the EAP-Request/AKA-Reauthentication packet, as
specified in Section 5. If the server does not recognize the re-		specified in Section 5. If the server does not recognize the re-
authentication identity, then it issues a second EAP-Request/AKA-		authentication identity, then it issues a second EAP-Request/AKA-
Identity message and includes the AT_FULLAUTH_ID_REQ attribute. In		Identity message and includes the AT_FULLAUTH_ID_REQ attribute. In
this case, a second EAP/AKA-Identity round trip is required. The		this case, a second EAP/AKA-Identity round trip is required. The
messages used on the first roundtrip are ignored. This is		messages used on the first roundtrip are ignored. This is
illustrated below.		illustrated below.
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Client Authenticator		Client Authenticator
| |		| |
| +------------------------------+		| +------------------------------+
| | Server does not have any |		| | Server does not have any |
| | Subscriber identity available|		| | Subscriber identity available|
| | When starting EAP/AKA |		| | When starting EAP/AKA |
| +------------------------------+		| +------------------------------+
| |		| |
| EAP-Request/AKA-Identity |		| EAP-Request/AKA-Identity |
| (AT_ANY_ID_REQ) |		| (AT_ANY_ID_REQ) |
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EAP/AKA includes optional identity privacy (anonymity) support that		EAP/AKA includes optional identity privacy (anonymity) support that
can be used to hide the cleartext permanent identity and to make the		can be used to hide the cleartext permanent identity and to make the
subscriber's connections unlinkable to eavesdroppers. Identity		subscriber's connections unlinkable to eavesdroppers. Identity
privacy is based on temporary identities, or pseudonyms, which are		privacy is based on temporary identities, or pseudonyms, which are
equivalent to but separate from the Temporary Mobile Subscriber		equivalent to but separate from the Temporary Mobile Subscriber
Identities (TMSI) that are used on cellular networks. Please see		Identities (TMSI) that are used on cellular networks. Please see
Section 12.1 for security considerations concerning identity		Section 12.1 for security considerations concerning identity
privacy.		privacy.
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If identity privacy is not used or if the client does not have any		If identity privacy is not used or if the client does not have any
pseudonyms or re-authentication identities available, the client		pseudonyms or re-authentication identities available, the client
transmits the permanent identity in the EAP-Response/Identity packet		transmits the permanent identity in the EAP-Response/Identity packet
or in the AT_IDENTITY attribute.		or in the AT_IDENTITY attribute.
The EAP-Request/AKA-Challenge message MAY include an encrypted		The EAP-Request/AKA-Challenge message MAY include an encrypted
pseudonym in the value field of the AT_ENCR_DATA attribute. The		pseudonym in the value field of the AT_ENCR_DATA attribute. The
AT_IV and AT_MAC attributes are also used to transport the pseudonym		AT_IV and AT_MAC attributes are also used to transport the pseudonym
to the client, as described in Section 8.1. Because the identity		to the client, as described in Section 8.1. Because the identity
Skipping to change at page ?, line 808 from start of file:
The client MAY transmit the received pseudonym in the first EAP-		The client MAY transmit the received pseudonym in the first EAP-
Response/Identity packet of the next full authentication with the		Response/Identity packet of the next full authentication with the
EAP server. The client concatenates the received pseudonym with the		EAP server. The client concatenates the received pseudonym with the
"@" character and the NAI realm portion. The client selects the		"@" character and the NAI realm portion. The client selects the
realm name portion similarly as it select the realm name portion		realm name portion similarly as it select the realm name portion
when using the permanent identity. If the EAP server successfully		when using the permanent identity. If the EAP server successfully
decodes the pseudonym received in the EAP-Response/Identity packet		decodes the pseudonym received in the EAP-Response/Identity packet
to a known client permanent identity, the authentication proceeds		to a known client permanent identity, the authentication proceeds
with the EAP-Request/AKA-Challenge message as usual.		with the EAP-Request/AKA-Challenge message as usual.
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Because the client may fail to save a pseudonym sent to in an EAP-		Because the client may fail to save a pseudonym sent to in an EAP-
Request/AKA-Challenge, for example due to malfunction, the EAP		Request/AKA-Challenge, for example due to malfunction, the EAP
server SHOULD maintain at least one old pseudonym in addition to the		server SHOULD maintain at least one old pseudonym in addition to the
most recent pseudonym.		most recent pseudonym.
If the EAP server requests the client to include its identity in the		If the EAP server requests the client to include its identity in the
EAP-Response/AKA-Identity packet, as specified in Section 4.2, the		EAP-Response/AKA-Identity packet, as specified in Section 4.2, the
client MAY transmit the received pseudonym in the AT_IDENTITY		client MAY transmit the received pseudonym in the AT_IDENTITY
attribute. If the EAP server successfully decodes the pseudonym to a		attribute. If the EAP server successfully decodes the pseudonym to a
known identity, then the authentication proceeds with the EAP-		known identity, then the authentication proceeds with the EAP-
Request/AKA-Challenge packet as usual.		Request/AKA-Challenge packet as usual.
If the EAP server fails to decode the pseudonym to a known identity,		If the EAP server fails to decode the pseudonym to a known identity,
then the EAP server requests the permanent identity (non-pseudonym		then the EAP server requests the permanent identity (non-pseudonym
identity) by including the AT_PERMANENT_ID_REQ attribute (Section		identity) by including the AT_PERMANENT_ID_REQ attribute (Section
8.5) in the EAP-Request/AKA-Challenge message.		8.5) in the EAP-Request/AKA-Identity message.
The EAP server issues the EAP-Request/AKA-Identity message also in		The EAP server issues the EAP-Request/AKA-Identity message also in
the case when it received the undecodable pseudonym in AT_IDENTITY		the case when it received the undecodable pseudonym in AT_IDENTITY
included in the EAP-Response/AKA-Identity packet. In this case, a		included in the EAP-Response/AKA-Identity packet. In this case, a
second EAP/AKA-Identity round trip is required.		second EAP/AKA-Identity round trip is required.
A received AT_PERMANENT_ID_REQ does not necessarily originate from		A received AT_PERMANENT_ID_REQ does not necessarily originate from
the valid network, but an active attacker may transmit an EAP-		the valid network, but an active attacker may transmit an EAP-
Request/AKA-Identity packet with an AT_PERMANENT_ID_REQ attribute to		Request/AKA-Identity packet with an AT_PERMANENT_ID_REQ attribute to
the client, in an effort to find out the true identity of the user.		the client, in an effort to find out the true identity of the user.
Skipping to change at page ?, line 866 from start of file:
permanent identity.		permanent identity.
The value field of the AT_PERMANENT_ID_REQ does not contain any data		The value field of the AT_PERMANENT_ID_REQ does not contain any data
but the attribute is included to request the client to include the		but the attribute is included to request the client to include the
AT_IDENTITY attribute (Section 8.6) with the permanent		AT_IDENTITY attribute (Section 8.6) with the permanent
authentication identity in the EAP-Response/AKA-Identity message. In		authentication identity in the EAP-Response/AKA-Identity message. In
this case, the AT_IDENTITY attribute contains the client's permanent		this case, the AT_IDENTITY attribute contains the client's permanent
identity in the clear.		identity in the clear.
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Please note that the EAP/AKA client and the EAP/AKA server only		Please note that the EAP/AKA client and the EAP/AKA server only
process the AT_IDENTITY attribute. Entities that only pass EAP		process the AT_IDENTITY attribute. Entities that only pass EAP
packets through do not process this attribute. Hence, if the EAP		packets through do not process this attribute. Hence, if the EAP
server is not co-located in the authenticator, then the		server is not co-located in the authenticator, then the
authenticator and other intermediate AAA elements (such as possible		authenticator and other intermediate AAA elements (such as possible
AAA proxy servers) will continue to refer to the client with the		AAA proxy servers) will continue to refer to the client with the
original identity from the EAP-Response/Identity packet regardless		original identity from the EAP-Response/Identity packet regardless
if the decoding fails in the EAP server.		if the decoding fails in the EAP server.
Skipping to change at page ?, line 914 from start of file:
After the EAP-Response/AKA-Identity message, the authentication		After the EAP-Response/AKA-Identity message, the authentication
sequence proceeds as usual with the EAP Server issuing the EAP-		sequence proceeds as usual with the EAP Server issuing the EAP-
Request/AKA-Challenge message.		Request/AKA-Challenge message.
The figure below illustrates the case when the EAP server fails to		The figure below illustrates the case when the EAP server fails to
decode the pseudonym included in the AT_IDENTITY attribute.		decode the pseudonym included in the AT_IDENTITY attribute.
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Client Authenticator		Client Authenticator
| |		| |
| +------------------------------+		| +------------------------------+
| | Server does not have any |		| | Server does not have any |
| | Subscriber identity available|		| | Subscriber identity available|
| | When starting EAP/AKA |		| | When starting EAP/AKA |
| +------------------------------+		| +------------------------------+
| |		| |
| EAP-Request/AKA-Identity |		| EAP-Request/AKA-Identity |
Skipping to change at page ?, line 964 from start of file:
authentication identity with a second EAP-Request/AKA-Identity. The		authentication identity with a second EAP-Request/AKA-Identity. The
client responds with a pseudonym identity in AT_IDENTITY. The server		client responds with a pseudonym identity in AT_IDENTITY. The server
fails to decode the pseudonym and has to issue a third EAP-		fails to decode the pseudonym and has to issue a third EAP-
Request/AKA-Identity, including AT_PERMANENT_ID_REQ. Finally, the		Request/AKA-Identity, including AT_PERMANENT_ID_REQ. Finally, the
server accepts the client's EAP-Response/AKA-Identity with the		server accepts the client's EAP-Response/AKA-Identity with the
AT_IDENTITY attribute and proceeds with full authentication. This is		AT_IDENTITY attribute and proceeds with full authentication. This is
illustrated in the figure below.		illustrated in the figure below.
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Client Authenticator		Client Authenticator
| |		| |
| +------------------------------+		| +------------------------------+
| | Server does not have any |		| | Server does not have any |
| | Subscriber identity available|		| | Subscriber identity available|
| | When starting EAP/AKA |		| | When starting EAP/AKA |
| +------------------------------+		| +------------------------------+
| |		| |
| EAP-Request/AKA-Identity |		| EAP-Request/AKA-Identity |
Skipping to change at page ?, line 1022 from start of file:
After the last EAP-Response/AKA-Identity message, the full		After the last EAP-Response/AKA-Identity message, the full
authentication sequence proceeds as usual with the EAP Server		authentication sequence proceeds as usual with the EAP Server
issuing the EAP-Request/AKA-Challenge message.		issuing the EAP-Request/AKA-Challenge message.
5. Re-authentication		5. Re-authentication
In some environments, EAP authentication may be performed		In some environments, EAP authentication may be performed
frequently. Because the EAP AKA full authentication procedure makes		frequently. Because the EAP AKA full authentication procedure makes
use of the UMTS AKA algorithms, and it therefore requires fresh		use of the UMTS AKA algorithms, and it therefore requires fresh
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authentication vectors from the Authentication Centre, the full		authentication vectors from the Authentication Centre, the full
authentication procedure may result in many network operations when		authentication procedure may result in many network operations when
used very frequently. Therefore, EAP AKA includes a more inexpensive		used very frequently. Therefore, EAP AKA includes a more inexpensive
re-authentication procedure that does not make use of the UMTS AKA		re-authentication procedure that does not make use of the UMTS AKA
algorithms and does not need new vectors from the Authentication		algorithms and does not need new vectors from the Authentication
Centre.		Centre.
Re-authentication is optional to implement for both the EAP AKA		Re-authentication is optional to implement for both the EAP AKA
server and client. On each EAP authentication, either one of the		server and client. On each EAP authentication, either one of the
entities may also fall back on full authentication if they do not		entities may also fall back on full authentication if they do not
want to use re-authentication.		want to use re-authentication.
Re-authentication is based on the keys derived on the preceding full		Re-authentication is based on the keys derived on the preceding full
authentication. The same K_aut and K_encr keys as in full		authentication. The same K_aut and K_encr keys as in full
authentication are used to protect EAP AKA packets and attributes,		authentication are used to protect EAP AKA packets and attributes,
and the original XKEY seed value from full authentication is used to		and the original Master Key from full authentication is used to
generate fresh application specific keys, as specified in Section		generate a fresh Master Session Key, as specified in Section 10.
10.
On re-authentication, the client protects against replays with an		On re-authentication, the client protects against replays with an
unsigned 16-bit counter, included in the AT_COUNTER attribute. On		unsigned 16-bit counter, included in the AT_COUNTER attribute. On
full authentication, both the server and the client initialize the		full authentication, both the server and the client initialize the
counter to one. The counter value of at least one is used on the		counter to one. The counter value of at least one is used on the
first re-authentication. On subsequent re-authentications, the		first re-authentication. On subsequent re-authentications, the
counter MUST be greater than on any of the previous re-		counter MUST be greater than on any of the previous re-
authentications. For example, on the second re-authentication,		authentications. For example, on the second re-authentication,
counter value is two or greater etc. The AT_COUNTER attribute is		counter value is two or greater etc. The AT_COUNTER attribute is
encrypted.		encrypted.
The server includes an encrypted server nonce (AT_NONCE_S) in the		The server includes an encrypted server nonce (AT_NONCE_S) in the
re-authentication request. The AT_MAC attribute in the client's		re-authentication request. The AT_MAC attribute in the client's
response is calculated over NONCE_S to provide a challenge/response		response is calculated over NONCE_S to provide a challenge/response
authentication scheme. The NONCE_S also contributes to the new		authentication scheme. The NONCE_S also contributes to the new
application specific keys.		Master Session Key.
As discussed in Section 4.3, in some environments the client may		As discussed in Section 4.3, in some environments the client may
assume that the network can reliably store pseudonyms and therefore		assume that the network can reliably store pseudonyms and therefore
the client may fail to respond to the AT_PERMANENT_ID_REQ attribute.		the client may fail to respond to the AT_PERMANENT_ID_REQ attribute.
The network SHOULD store pseudonyms on a reliable database. Because		The network SHOULD store pseudonyms on a reliable database. Because
one of the objectives of the re-authentication procedure is to		one of the objectives of the re-authentication procedure is to
reduce load on the network, the re-authentication procedure does not		reduce load on the network, the re-authentication procedure does not
require the EAP server to contact a reliable database. Therefore,		require the EAP server to contact a reliable database. Therefore,
the re-authentication procedure makes use of separate re-		the re-authentication procedure makes use of separate re-
authentication user identities. Pseudonyms and the permanent		authentication user identities. Pseudonyms and the permanent
identity are reserved for full authentication only. The network does		identity are reserved for full authentication only. The network does
not need to store re-authentication identities as carefully as		not need to store re-authentication identities as carefully as
pseudonyms. If a re-authentication identity is lost and the network		pseudonyms. If a re-authentication identity is lost and the network
does not recognize it, the EAP server can fall back on full		does not recognize it, the EAP server can fall back on full
authentication.		authentication.
If the EAP server supports re-authentication, it MAY include the		If the EAP server supports re-authentication, it MAY include the
skippable AT_NEXT_REAUTH_ID attribute in the encrypted data of EAP-		skippable AT_NEXT_REAUTH_ID attribute in the encrypted data of EAP-
Request/AKA-Challenge message. This attribute contains a new re-		Request/AKA-Challenge message. This attribute contains a new re-
authentication identity for the next re-authentication. The client		authentication identity for the next re-authentication. The client
		MAY ignore this attribute, in which case it will use full
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MAY ignore this attribute, in which case it will use full
authentication next time. If the client wants to use re-		authentication next time. If the client wants to use re-
authentication, it uses this re-authentication identity on next		authentication, it uses this re-authentication identity on next
authentication. Even if the client has a re-authentication identity,		authentication. Even if the client has a re-authentication identity,
the client MAY discard the re-authentication identity and use a		the client MAY discard the re-authentication identity and use a
pseudonym or the permanent identity instead, in which case full		pseudonym or the permanent identity instead, in which case full
authentication will be performed.		authentication will be performed.
The re-authentication identity received in AT_NEXT_REAUTH_ID		The re-authentication identity received in AT_NEXT_REAUTH_ID
contains both the username portion and the realm portion of the		contains both the username portion and the realm portion of the
Network Access Identifier. The EAP Server can choose an appropriate		Network Access Identifier. The EAP Server can choose an appropriate
Skipping to change at page ?, line 1128 from start of file:
AT_FULLAUTH_ID_REQ or AT_PERMANENT_ID_REQ attributes if it does not		AT_FULLAUTH_ID_REQ or AT_PERMANENT_ID_REQ attributes if it does not
know the client's identity.)		know the client's identity.)
Both the client and the server SHOULD have an upper limit for the		Both the client and the server SHOULD have an upper limit for the
number of subsequent re-authentications allowed before a full		number of subsequent re-authentications allowed before a full
authentication needs to be performed. Because a 16-bit counter is		authentication needs to be performed. Because a 16-bit counter is
used in re-authentication, the theoretical maximum number of re-		used in re-authentication, the theoretical maximum number of re-
authentications is reached when the counter value reaches 0xFFFF.		authentications is reached when the counter value reaches 0xFFFF.
In order to use re-authentication, the client and the server need to		In order to use re-authentication, the client and the server need to
store the following values: original XKEY, K_aut, K_encr, latest		store the following values: original Master Key, K_aut, K_encr,
counter value and the next re-authentication identity.		latest counter value and the next re-authentication identity.
The following figure illustrates the re-authentication procedure.		The following figure illustrates the re-authentication procedure.
Encrypted attributes are denoted with '*'. The client uses its re-		Encrypted attributes are denoted with '*'. The client uses its re-
authentication identity in the EAP-Response/Identity packet. As		authentication identity in the EAP-Response/Identity packet. As
discussed above, an alternative way to communicate the re-		discussed above, an alternative way to communicate the re-
authentication identity to the server is for the client to use the		authentication identity to the server is for the client to use the
AT_IDENTITY attribute in the EAP-Response/AKA-Identity message. This		AT_IDENTITY attribute in the EAP-Response/AKA-Identity message. This
		latter case is not illustrated in the figure below, and it is only
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latter case is not illustrated in the figure below, and it is only
possible when the server requests the client to send its identity by		possible when the server requests the client to send its identity by
including the AT_ANY_ID_REQ attribute in the EAP-Request/AKA-		including the AT_ANY_ID_REQ attribute in the EAP-Request/AKA-
Identity packet.		Identity packet.
If the server recognizes the re-authentication identity and agrees		If the server recognizes the re-authentication identity and agrees
on using re-authentication, then the server sends the EAP-		on using re-authentication, then the server sends the EAP-
Request/AKA-Reauthentication packet to the client. This packet MUST		Request/AKA-Reauthentication packet to the client. This packet MUST
include the encrypted AT_COUNTER attribute, with a fresh counter		include the encrypted AT_COUNTER attribute, with a fresh counter
value, the encrypted AT_NONCE_S attribute that contains a random		value, the encrypted AT_NONCE_S attribute that contains a random
number chosen by the server, the AT_ENCR_DATA and the AT_IV		number chosen by the server, the AT_ENCR_DATA and the AT_IV
Skipping to change at page ?, line 1178 from start of file:
same counter value and the AT_MAC attribute.		same counter value and the AT_MAC attribute.
The server verifies the AT_MAC attribute and also verifies that the		The server verifies the AT_MAC attribute and also verifies that the
counter value is the same that it used in the EAP-Request/AKA-		counter value is the same that it used in the EAP-Request/AKA-
Reauthentication packet. If these checks are successful, the re-		Reauthentication packet. If these checks are successful, the re-
authentication has succeeded and the server sends the EAP-Success		authentication has succeeded and the server sends the EAP-Success
packet to the client.		packet to the client.
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Client Authenticator		Client Authenticator
| |		| |
| EAP-Request/Identity |		| EAP-Request/Identity |
|<------------------------------------------------------|		|<------------------------------------------------------|
| |		| |
| EAP-Response/Identity |		| EAP-Response/Identity |
| (Includes a re-authentication identity) |		| (Includes a re-authentication identity) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
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If the client does not accept the counter value of EAP-Request/AKA-		If the client does not accept the counter value of EAP-Request/AKA-
Reauthentication, it indicates the counter synchronization problem		Reauthentication, it indicates the counter synchronization problem
by including the encrypted AT_COUNTER_TOO_SMALL in EAP-Response/AKA-		by including the encrypted AT_COUNTER_TOO_SMALL in EAP-Response/AKA-
Reauthentication. The server responds with EAP-Request/AKA-Challenge		Reauthentication. The server responds with EAP-Request/AKA-Challenge
to initiate a normal full authentication procedure. This is		to initiate a normal full authentication procedure. This is
illustrated in the following figure. Encrypted attributes are		illustrated in the following figure. Encrypted attributes are
denoted with '*'.		denoted with '*'.
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Client Authenticator		Client Authenticator
| |		| |
| EAP-Request/Identity |		| EAP-Request/Identity |
|<------------------------------------------------------|		|<------------------------------------------------------|
| |		| |
| EAP-Response/Identity |		| EAP-Response/Identity |
| (Includes a re-authentication identity) |		| (Includes a re-authentication identity) |
|------------------------------------------------------>|		|------------------------------------------------------>|
| |		| |
Skipping to change at page ?, line 1290 from start of file:
verifies that AT_COUNTER contains the same as in the EAP-		verifies that AT_COUNTER contains the same as in the EAP-
Request/AKA-Reauthentication packet. If not, the server silently		Request/AKA-Reauthentication packet. If not, the server silently
discards the EAP-Response/AKA-Reauthentication packet. If all checks		discards the EAP-Response/AKA-Reauthentication packet. If all checks
on the packet are successful, the server transmits a EAP-		on the packet are successful, the server transmits a EAP-
Request/AKA-Challenge packet and the full authentication procedure		Request/AKA-Challenge packet and the full authentication procedure
is performed as usual. Since the server already knows the subscriber		is performed as usual. Since the server already knows the subscriber
identity, it MUST NOT use the EAP-Request/AKA-Identity packet to		identity, it MUST NOT use the EAP-Request/AKA-Identity packet to
request the identity.		request the identity.
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6. Message Format		6. Message Format
The Type-Data of the EAP AKA packets begins with a 1-octet Subtype		The Type-Data of the EAP AKA packets begins with a 1-octet Subtype
field, which is followed by a 2-octet reserved field. The rest of		field, which is followed by a 2-octet reserved field. The rest of
the Type-Data consists of attributes that are encoded in Type,		the Type-Data consists of attributes that are encoded in Type,
Length, Value format. The figure below shows the generic format of		Length, Value format. The figure below shows the generic format of
an attribute.		an attribute.
0 1 2 3		0 1 2 3
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EAP/AKA packets do not include a version field. However, should		EAP/AKA packets do not include a version field. However, should
there be a reason to revise this protocol in the future, new non-		there be a reason to revise this protocol in the future, new non-
skippable or skippable attributes could be specified in order to		skippable or skippable attributes could be specified in order to
implement revised EAP/AKA versions in a backward-compatible manner.		implement revised EAP/AKA versions in a backward-compatible manner.
Unless otherwise specified, the order of the attributes in an EAP		Unless otherwise specified, the order of the attributes in an EAP
AKA message is insignificant, and an EAP AKA implementation should		AKA message is insignificant, and an EAP AKA implementation should
not assume a certain order to be used.		not assume a certain order to be used.
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Attributes can be encapsulated within other attributes. In other		Attributes can be encapsulated within other attributes. In other
words, the value field of an attribute type can be specified to		words, the value field of an attribute type can be specified to
contain other attributes.		contain other attributes.
7. Message Authentication and Encryption		7. Message Authentication and Encryption
This section specifies EAP/AKA attributes for attribute encryption		This section specifies EAP/AKA attributes for attribute encryption
and EAP/AKA message authentication.		and EAP/AKA message authentication.
Skipping to change at page ?, line 1406 from start of file:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |		| |
| MAC |		| MAC |
| |		| |
| |		| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The MAC algorithm is HMAC-SHA1-128 [9] keyed hash value. (The		The MAC algorithm is HMAC-SHA1-128 [9] keyed hash value. (The
HMAC-SHA1-128 value is obtained from the 20-byte HMAC-SHA1 value		HMAC-SHA1-128 value is obtained from the 20-byte HMAC-SHA1 value
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by truncating the output to 16 bytes. Hence, the length of the		by truncating the output to 16 bytes. Hence, the length of the
MAC is 16 bytes.) The message authentication key (K_aut) used in		MAC is 16 bytes.) The message authentication key (K_aut) used in
the calculation of the MAC is derived from the AKA integrity key		the calculation of the MAC is derived from the AKA integrity key
(IK) and cipher key (CK), as specified in Section 10.		(IK) and cipher key (CK), as specified in Section 10.
7.2. AT_IV, AT_ENCR_DATA and AT_PADDING Attributes		7.2. AT_IV, AT_ENCR_DATA and AT_PADDING Attributes
AT_IV and AT_ENCR_DATA attributes can be optionally used to transmit		AT_IV and AT_ENCR_DATA attributes can be optionally used to transmit
encrypted information between the EAP/AKA client and server.		encrypted information between the EAP/AKA client and server.
Skipping to change at page ?, line 1464 from start of file:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_ENCR_DATA | Length | Reserved |		| AT_ENCR_DATA | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |		| |
. Encrypted Data .		. Encrypted Data .
. .		. .
| |		| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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The encryption key (K_encr) is derived is derived from the AKA		The encryption key (K_encr) is derived is derived from the AKA
integrity key (IK) and cipher key (CK), as specified in Section10.		integrity key (IK) and cipher key (CK), as specified in Section10.
The plaintext consists of nested EAP/AKA attributes.		The plaintext consists of nested EAP/AKA attributes.
The encryption algorithm requires the length of the plaintext to be		The encryption algorithm requires the length of the plaintext to be
a multiple of 16 bytes. The sender may need to include the		a multiple of 16 bytes. The sender may need to include the
AT_PADDING attribute as the last attribute within AT_ENCR_DATA. The		AT_PADDING attribute as the last attribute within AT_ENCR_DATA. The
AT_PADDING attribute is not included if the total length of other		AT_PADDING attribute is not included if the total length of other
Skipping to change at page ?, line 1504 from start of file:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
8. Messages		8. Messages
8.1. EAP-Request/AKA-Challenge		8.1. EAP-Request/AKA-Challenge
The format of the EAP-Request/AKA-Challenge packet is shown below.		The format of the EAP-Request/AKA-Challenge packet is shown below.
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0 1 2 3		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		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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |		| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Subtype | Reserved |		| Type | Subtype | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_RAND | Length = 5 | Reserved |		| AT_RAND | Length = 5 | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Skipping to change at page ?, line 1561 from start of file:
Code		Code
1 for Request		1 for Request
Identifier		Identifier
See [5]		See [5]
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Length		Length
The length of the EAP Request packet.		The length of the EAP Request packet.
Type		Type
23		23
Subtype		Subtype
Skipping to change at page ?, line 1618 from start of file:
In the EAP-Request/AKA-Challege message, the AT_IV, AT_ENCR_DATA and		In the EAP-Request/AKA-Challege message, the AT_IV, AT_ENCR_DATA and
AT_MAC attributes are used for Identity privacy and for		AT_MAC attributes are used for Identity privacy and for
communicating the next re-authentication identity. The plaintext of		communicating the next re-authentication identity. The plaintext of
the AT_ENCR_DATA value field consists of nested attributes, which		the AT_ENCR_DATA value field consists of nested attributes, which
are shown below. Later versions of this protocol MAY specify		are shown below. Later versions of this protocol MAY specify
additional attributes to be included within the encrypted data.		additional attributes to be included within the encrypted data.
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0 1 2 3		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		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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_NEXT_PS... | Length | Actual Pseudonym Length |		| AT_NEXT_PS... | Length | Actual Pseudonym Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |		| |
. Next Pseudonym .		. Next Pseudonym .
. .		. .
| |		| |
Skipping to change at page ?, line 1676 from start of file:
identity does not include any terminating null characters.		identity does not include any terminating null characters.
Because the length of the attribute must be a multiple of 4		Because the length of the attribute must be a multiple of 4
bytes, the sender pads the re-authentication identity with zero		bytes, the sender pads the re-authentication identity with zero
bytes when necessary.		bytes when necessary.
AT_PADDING		AT_PADDING
AT_PADDING is optional to include. See Section 7.2.		AT_PADDING is optional to include. See Section 7.2.
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8.2. EAP-Response/AKA-Challenge		8.2. EAP-Response/AKA-Challenge
The format of the EAP-Response/AKA-Challenge packet is shown below.		The format of the EAP-Response/AKA-Challenge packet is shown below.
Later versions of this protocol MAY make use of the AT_ENCR_DATA and		Later versions of this protocol MAY make use of the AT_ENCR_DATA and
AT_IV attributes in this message to include encrypted (skippable)		AT_IV attributes in this message to include encrypted (skippable)
attributes. AT_MAC, AT_ENCR_DATA and AT_IV attributes are not shown		attributes. AT_MAC, AT_ENCR_DATA and AT_IV attributes are not shown
in the figure below. If present, they are processed as in EAP-		in the figure below. If present, they are processed as in EAP-
Request/AKA-Challenge packet. The EAP server MUST process EAP-		Request/AKA-Challenge packet. The EAP server MUST process EAP-
Skipping to change at page ?, line 1732 from start of file:
Length		Length
The length of the EAP Response packet.		The length of the EAP Response packet.
Type		Type
23		23
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Subtype		Subtype
1 for AKA-Challenge		1 for AKA-Challenge
Reserved		Reserved
Set to zero when sending, ignored on reception.		Set to zero when sending, ignored on reception.
AT_RES		AT_RES
Skipping to change at page ?, line 1790 from start of file:
See [5]		See [5]
Length		Length
The length of the EAP Response packet.		The length of the EAP Response packet.
Type		Type
23		23
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Subtype		Subtype
2 for AKA-Authentication-Reject		2 for AKA-Authentication-Reject
Reserved		Reserved
Set to zero on sending, ignored on reception.		Set to zero on sending, ignored on reception.
Skipping to change at page ?, line 1844 from start of file:
Type		Type
23		23
Subtype		Subtype
4 for AKA-Synchronization-Failure		4 for AKA-Synchronization-Failure
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AT_AUTS		AT_AUTS
This attribute MUST be included in EAP-Response/AKA-		This attribute MUST be included in EAP-Response/AKA-
Synchronization-Failure. The value field of this attribute		Synchronization-Failure. The value field of this attribute
contains the AKA AUTS parameter, 112 bits (14 bytes).		contains the AKA AUTS parameter, 112 bits (14 bytes).
8.5. EAP-Request/AKA-Identity		8.5. EAP-Request/AKA-Identity
The format of the EAP-Request/AKA-Identity packet is shown below.		The format of the EAP-Request/AKA-Identity packet is shown below.
Skipping to change at page ?, line 1902 from start of file:
Reserved		Reserved
Set to zero on sending, ignored on reception.		Set to zero on sending, ignored on reception.
AT_PERMANENT_ID_REQ		AT_PERMANENT_ID_REQ
The AT_PERMANENT_ID_REQ attribute is optional to include and it		The AT_PERMANENT_ID_REQ attribute is optional to include and it
is included in the cases defined in Section 4.3. It MUST NOT be		is included in the cases defined in Section 4.3. It MUST NOT be
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included if AT_ANY_ID_REQ or AT_FULLAUTH_ID_REQ is included. The		included if AT_ANY_ID_REQ or AT_FULLAUTH_ID_REQ is included. The
value field only contains two reserved bytes, which are set to		value field only contains two reserved bytes, which are set to
zero on sending and ignored on reception.		zero on sending and ignored on reception.
AT_FULLAUTH_ID_REQ		AT_FULLAUTH_ID_REQ
The AT_FULLAUTH_ID_REQ attribute is optional to include and it is		The AT_FULLAUTH_ID_REQ attribute is optional to include and it is
included in the cases defined in Section 4.2. It MUST NOT be		included in the cases defined in Section 4.2. It MUST NOT be
included if AT_ANY_ID_REQ or AT_PERMANENT_ID_REQ is included. The		included if AT_ANY_ID_REQ or AT_PERMANENT_ID_REQ is included. The
Skipping to change at page ?, line 1959 from start of file:
Identifier		Identifier
See [5]		See [5]
Length		Length
The length of the EAP Response packet.		The length of the EAP Response packet.
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Type		Type
23		23
Subtype		Subtype
5 for AKA-Identity		5 for AKA-Identity
Reserved		Reserved
Skipping to change at page ?, line 1998 from start of file:
when necessary.		when necessary.
8.7. EAP-Request/AKA-Reauthentication		8.7. EAP-Request/AKA-Reauthentication
The format of the EAP-Request/AKA-Reauthentication packet is shown		The format of the EAP-Request/AKA-Reauthentication packet is shown
below.		below.
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0 1 2 3		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		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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |		| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Subtype | Reserved |		| Type | Subtype | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_IV | Length = 5 | Reserved |		| AT_IV | Length = 5 | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Skipping to change at page ?, line 2056 from start of file:
Subtype		Subtype
13		13
Reserved		Reserved
Set to zero when sending, ignored on reception.		Set to zero when sending, ignored on reception.
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AT_IV		AT_IV
The AT_IV attribute is MUST be included. See Section 7.2.		The AT_IV attribute is MUST be included. See Section 7.2.
AT_ENCR_DATA		AT_ENCR_DATA
The AT_ENCR_DATA attribute MUST be included. See Section 7.2. The		The AT_ENCR_DATA attribute MUST be included. See Section 7.2. The
plaintext consists of nested attributes as described below.		plaintext consists of nested attributes as described below.
Skipping to change at page ?, line 2114 from start of file:
The AT_COUNTER attribute MUST be included. The value field		The AT_COUNTER attribute MUST be included. The value field
consists of a 16-bit unsigned integer counter value, represented		consists of a 16-bit unsigned integer counter value, represented
in network byte order.		in network byte order.
AT_NONCE_S		AT_NONCE_S
The AT_NONCE_S attribute MUST be included. The value field		The AT_NONCE_S attribute MUST be included. The value field
contains two reserved bytes followed by a random number generated		contains two reserved bytes followed by a random number generated
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by the server (16 bytes) freshly for this EAP/AKA re-		by the server (16 bytes) freshly for this EAP/AKA re-
authentication. The random number is used as challenge for the		authentication. The random number is used as challenge for the
client and also a seed value for the new keying material. The		client and also a seed value for the new keying material. The
reserved bytes are set to zero upon sending and ignored upon		reserved bytes are set to zero upon sending and ignored upon
reception.		reception.
AT_NEXT_REAUTH_ID		AT_NEXT_REAUTH_ID
The AT_NEXT_REAUTH_ID attribute is optional to include. The		The AT_NEXT_REAUTH_ID attribute is optional to include. The
Skipping to change at page ?, line 2172 from start of file:
| MAC |		| MAC |
| |		| |
| |		| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Code		Code
2 for Response		2 for Response
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Identifier		Identifier
See [5].		See [5].
Length		Length
The length of the EAP packet.		The length of the EAP packet.
Type		Type
Skipping to change at page ?, line 2212 from start of file:
plaintext consists of nested attributes as described below.		plaintext consists of nested attributes as described below.
AT_MAC		AT_MAC
For EAP-Response/AKA-Reauthentication, the MAC code is calculated		For EAP-Response/AKA-Reauthentication, the MAC code is calculated
over the following data:		over the following data:
EAP packet| NONCE_S		EAP packet| NONCE_S
The EAP packet is represented as specified in Section 7.1. It is		The EAP packet is represented as specified in Section 7.1. It is
followed by the 16-byte NONCE_S value from the client's		followed by the 16-byte NONCE_S value from the server's
AT_NONCE_S attribute.		AT_NONCE_S attribute.
The AT_IV and AT_ENCR_DATA attributes are used for communicating		The AT_IV and AT_ENCR_DATA attributes are used for communicating
encrypted attributes. The plaintext of the AT_ENCR_DATA value field		encrypted attributes. The plaintext of the AT_ENCR_DATA value field
consists of nested attributes, which are shown below.		consists of nested attributes, which are shown below.
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0 1 2 3		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		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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_COUNTER | Length = 1 | Counter |		| AT_COUNTER | Length = 1 | Counter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_COUNTER...| Length = 1 | Reserved |		| AT_COUNTER...| Length = 1 | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AT_PADDING | Length | Padding... |		| AT_PADDING | Length | Padding... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
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AT_PADDING		AT_PADDING
The AT_PADDING attribute is optional to include. See section 7.2		The AT_PADDING attribute is optional to include. See section 7.2
8.9. EAP/AKA Notifications		8.9. EAP/AKA Notifications
The EAP-Request/Notification, specified in [5], can be used to		The EAP-Request/Notification, specified in [5], can be used to
convey a displayable message from the authenticator to the client.		convey a displayable message from the authenticator to the client.
Because these messages are textual messages, it may be hard for the		Because these messages are textual messages, it may be hard for the
client to present them in the userÆs preferred language. Therefore,		client to present them in the user's preferred language. Therefore,
EAP/AKA uses a separate EAP/AKA message subtype to transmit		EAP/AKA uses a separate EAP/AKA message subtype to transmit
localizable notification codes instead of the EAP-		localizable notification codes instead of the EAP-
Request/Notification packet.		Request/Notification packet.
The EAP server MAY issue an EAP-Request/AKA-Notification packet to		The EAP server MAY issue an EAP-Request/AKA-Notification packet to
the client. The client MAY delay the processing of EAP-Request/AKA-		the client. The client MAY delay the processing of EAP-Request/AKA-
Notification and wait for other EAP/AKA requests. If a valid EAP/AKA		Notification and wait for other EAP/AKA requests. If a valid EAP/AKA
request of another subtype is received, the client MAY silently		request of another subtype is received, the client MAY silently
ignore the EAP-Request/AKA-Notification and process the other		ignore the EAP-Request/AKA-Notification and process the other
EAP/AKA request instead. If the client decides to process the EAP-		EAP/AKA request instead. If the client decides to process the EAP-
Skipping to change at page ?, line 2279 from start of file:
message to the user and the client MUST respond to the EAP server		message to the user and the client MUST respond to the EAP server
with an EAP-Response/AKA-Notification packet, even if the client did		with an EAP-Response/AKA-Notification packet, even if the client did
not recognize the notification code. The processing of EAP-		not recognize the notification code. The processing of EAP-
Request/AKA-Notification MUST NOT result in any change in the client		Request/AKA-Notification MUST NOT result in any change in the client
state. For example, the client MUST NOT assume that the receipt of		state. For example, the client MUST NOT assume that the receipt of
an EAP-Request/AKA-Notification indicates failed authentication.		an EAP-Request/AKA-Notification indicates failed authentication.
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On full authentication, AT_MAC MUST be included in EAP/AKA		On full authentication, AT_MAC MUST be included in EAP/AKA
Notification packets if a new K_aut key is available and MUST NOT be		Notification packets if a new K_aut key is available and MUST NOT be
included if K_aut has not been derived yet. In other words, AT_MAC		included if K_aut has not been derived yet. In other words, AT_MAC
MUST be included on full authentication if and only if the EAP/AKA-		MUST be included on full authentication if and only if the EAP/AKA-
Challenge roundtrip has been performed. On re-authentication,		Challenge roundtrip has been performed. On re-authentication,
EAP/AKA-Notification packets MUST be protected with AT_MAC because		EAP/AKA-Notification packets MUST be protected with AT_MAC because
K_aut is always available.		K_aut is always available.
Some of the notification codes are authorization related and hence		Some of the notification codes are authorization related and hence
Skipping to change at page ?, line 2336 from start of file:
Length		Length
The length of the EAP packet.		The length of the EAP packet.
Type		Type
23		23
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Subtype		Subtype
12		12
Reserved		Reserved
Set to zero when sending, ignored on reception.		Set to zero when sending, ignored on reception.
AT_NOTIFICATION		AT_NOTIFICATION
The AT_NOTIFICATION attribute MUST be included. The value field		The AT_NOTIFICATION attribute MUST be included. The value field
of this attribute contains a two-byte notification code. The		of this attribute contains a two-byte notification code. The
following code values have been reserved. The descriptions below		following code values have been reserved. The descriptions below
illustrate the semantics of the notifications. The client		illustrate the semantics of the notifications. The client
implementation MAY use different wordings when presenting the		implementation MAY use different wordings when presenting the
notifications to the user. The "requested service" depends on the		notifications to the user. The "requested service" depends on the
environment where EAP/AKA is applied.		environment where EAP/AKA is applied.
1026 û User has been temporarily denied access to the requested		1026 - User has been temporarily denied access to the requested
service		service
1031 - User has not subscribed to the requested service		1031 - User has not subscribed to the requested service
AT_MAC		AT_MAC
AT_MAC is included in cases described above. No message-specific		AT_MAC is included in cases described above. No message-specific
data is included in the MAC calculation. See Section 7.1.		data is included in the MAC calculation. See Section 7.1.
Skipping to change at page ?, line 2394 from start of file:
| MAC |		| MAC |
| |		| |
| |		| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Code		Code
2 for Response		2 for Response
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Identifier		Identifier
See [5].		See [5].
Length		Length
The length of the EAP packet.		The length of the EAP packet.
Type		Type
Skipping to change at page ?, line 2446 from start of file:
subtype, the EAP/AKA client MUST silently discard the EAP request.		subtype, the EAP/AKA client MUST silently discard the EAP request.
As normally in EAP, the EAP server sends the EAP-Failure packet to		As normally in EAP, the EAP server sends the EAP-Failure packet to
the client when the authentication procedure fails on the EAP		the client when the authentication procedure fails on the EAP
Server. In EAP/AKA, this may occur for example if the EAP server is		Server. In EAP/AKA, this may occur for example if the EAP server is
not able to obtain authentication vectors for the subscriber or the		not able to obtain authentication vectors for the subscriber or the
authentication exchange times out.		authentication exchange times out.
10. Key Derivation		10. Key Derivation
This section specifies how EAP AKA keying material is derived from		This section specifies how EAP AKA keying material is derived.
the IK and CK keys.
EAP AKA requires two keys for its own purposes, a message		On EAP AKA full authentication, a Master Key (MK) is derived from
authentication key K_aut and an encryption key K_encr, to be used		the underlying UMTS AKA values (IK and CK keys) and the Identity as
		follows.
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		MK = SHA1(Identity|IK|CK)
		In the formula above, the "|" character denotes concatenation.
		Identity denotes the user identity string without any terminating
		null characters. It is the identity from the AT_IDENTITY attribute
		from the last EAP-Response/AKA-Identity packet, or, if AT_IDENTITY
		was not used, the identity from the EAP-Response/Identity packet.
		The Master Key is fed into a Pseudo-Random number Function (PRF)
		which generates separate Transient EAP Keys (TEKs) for protecting
		EAP AKA packets and a Master Session Key (MSK) for other purposes,
		such as protecting traffic between the client and the authenticator.
		Initialization Vector (IV) values are also generated. On re-
		authentication, the same TEKs will be used for protecting EAP
		packets, but a new MSK and new IVs will be derived from the original
		MK and new values exchanged in the re-authentication.
		EAP AKA requires two TEKs for its own purposes, a message
		authentication key K_aut and an encryption key K_encr, to be used
with the AT_MAC and AT_ENCR_DATA attributes. The same K_aut and		with the AT_MAC and AT_ENCR_DATA attributes. The same K_aut and
K_encr keys are used in full authentication and subsequent re-		K_encr keys are used in full authentication and subsequent re-
authentications. In addition, it is possible to derive additional		authentications.
application specific key material, such as a master key to be used
with IEEE 802.11i.
Key derivation is based on the pseudo-random number generator		Key derivation is based on the pseudo-random number generator
specified in NIST Federal Information Processing Standards		specified in NIST Federal Information Processing Standards
Publication 186-2 [13]. The pseudo-random number generator is		Publication 186-2 [13]. The pseudo-random number generator is
specified in the change notice 1 (2001 October 5)of [13] (Algorithm		specified in the change notice 1 (2001 October 5)of [13] (Algorithm
1). As specified in the change notice (page 74), when Algorithm 1 is		1). As specified in the change notice (page 74), when Algorithm 1 is
used as a general-purpose random number generator, the "mod q" term		used as a general-purpose random number generator, the "mod q" term
in step 3.2 is omitted. The function G used in the algorithm is		in step 3.2 is omitted. The function G used in the algorithm is
constructed via Secure Hash Standard as specified in Appendix 3.3 of		constructed via Secure Hash Standard as specified in Appendix 3.3 of
the standard. For convenience, the pseudo-random number algorithm		the standard. For convenience, the pseudo-random number algorithm
with the correct modification is cited in Annex A.		with the correct modification is cited in Annex A.
160-bit XKEY and XVAL values are used, so b = 160. The initial		160-bit XKEY and XVAL values are used, so b = 160. On full
secret seed value XKEY is computed from the AKA integrity key IK and		authentication, the Master Key is used as the initial secret seed
cipher key CK with the following formula:		value XKEY
XKEY = SHA1(Identity|IK|CK)
In the formula above, the "|" character denotes concatenation.
Identity denotes the user identity string without any terminating
null characters. It is the identity from the AT_IDENTITY attribute
from the last EAP-Response/AKA-Identity packet, or, if AT_IDENTITY
was not used, the identity from the EAP-Response/Identity packet.
The optional user input values (XSEED_j) in Step 3.1 are set to		The optional user input values (XSEED_j) in Step 3.1 are set to
zero.		zero.
The resulting 320-bit random numbers x_0, x_1, ..., x_m-1 are		The resulting 320-bit random numbers x_0, x_1, ..., x_m-1 are
concatenated and partitioned into suitable-sized chunks and used as		concatenated and partitioned into suitable-sized chunks and used as
keys in the following order: K_encr (128 bits), K_aut (128 bits),		keys in the following order: K_encr (128 bits), K_aut (128 bits),
EAP application specific keys. The EAP application specific material		Master Session Key (128 bytes), Initialization Vectors (64 bytes).
immediately follows K_aut.
On re-authentication, the same pseudo-random number generator can be		On re-authentication, the same pseudo-random number generator can be
used to generate new application specific keys. The seed value XKEYÆ		used to generate a new Master Session Key and new Initializatin
is calculated as follows:		Vectors. The seed value XKEY' is calculated as follows:
		XKEY' = SHA1(Identity|counter|NONCE_S|MK)
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In the formula above, the Identity denotes the re-authentication		In the formula above, the Identity denotes the re-authentication
user identity, without any terminating null characters, from the		user identity, without any terminating null characters, from the
AT_IDENTITY attribute of the EAP-Response/AKA-Identity packet, or,		AT_IDENTITY attribute of the EAP-Response/AKA-Identity packet, or,
if EAP-Response/AKA-Identity was not used on re-authentication, the		if EAP-Response/AKA-Identity was not used on re-authentication, the
identity string from the EAP-Response/Identity packet. The counter		identity string from the EAP-Response/Identity packet. The counter
denotes the counter value from AT_COUNTER attribute used in the EAP-		denotes the counter value from AT_COUNTER attribute used in the EAP-
Response/AKA-Reauthentication packet. The counter is used in network		Response/AKA-Reauthentication packet. The counter is used in network
byte order. NONCE_S denotes the 16-byte NONCE_S value from the		byte order. NONCE_S denotes the 16-byte NONCE_S value from the
AT_NONCE_S attribute used in the EAP-Request/AKA-Reauthentication		AT_NONCE_S attribute used in the EAP-Request/AKA-Reauthentication
packet. The original XKEY is the XKEY value from the preceding full		packet. The MK is the Master Key from the preceding full
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authentication. The pseudo-random number generator is run with the		authentication. The pseudo-random number generator is run with the
new seed value XKEYÆ, and the resulting 320-bit random numbers x_0,		new seed value XKEY', and the resulting 320-bit random numbers x_0,
x_1, ..., x_m-1 are concatenated and partitioned into suitable-sized		x_1, ..., x_m-1 are concatenated and partitioned into suitable-sized
chunks and used as new application specific keys.		chunks and used as the new Master Session Key and new Initialization
		Vectors. For example, the Master Session Key and the Initialization
For example, the EAP application specific material can be used for		Vectors can be used for packet security between the client and the
packet security between the client and the authenticator. EAP AKA		authenticator.
always generates 192 bytes of application specific keying material.
The keying material consists of six 32-byte chunks. The six 32-byte		In the absence of a general EAP keying specification, EAP AKA
chunks may be truncated to correct length and used as keys and		generates the same amount of MSK and IV material as EAP TLS [14]. A
initialization vectors in the following order:		128-byte Master Session Key and two 32-byte Initialization Vectors
		are derived. If EAP TLS compatible keying material is needed, then
First 32 bytes: uplink or bi-directional encryption key		the generated keying and IV material can be divided into six 32-byte
Second 32 bytes: downlink encryption key		chunks and used in the same order as specified in Section 3.5 of
Third 32 bytes: uplink or bi-directional message integrity		[14].
protection key
Fourth 32 bytes: downlink message integrity protection key		The first 32 bytes of the MSK can be used as the Pairwise Master Key
Fifth 32 bytes: uplink initialization vector		(PMK) for IEEE 802.11i.
Sixth 32 bytes: downlink initialization vector
		When the RADIUS attributes specified in [15] are used to transport
"Uplink" refers to data sent from the client to the authenticator,		keying material, then the first 32 bytes of the MSK correspond to
and "downlink" to the data sent from the authenticator to the		MS-MPPE-RECV-KEY and the second 32 bytes to MS-MPPE-SEND-KEY. In
client.		this case, only 64 bytes of keying material are used.
If only one master session key is needed, then the first 32 bytes
(uplink encryption key) are used as the master session key.
When the RADIUS attributes specified in [14] are used to transport
keying material, then the first 32 bytes correspond to MS-MPPE-RECV-
KEY and the second 32 bytes to MS-MPPE-SEND-KEY. In this case, only
64 bytes of keying material are used.
11. IANA and Protocol Numbering Considerations		11. IANA and Protocol Numbering Considerations
The realm name "owlan.org" has been reserved for NAI realm names		The realm name "owlan.org" has been reserved for NAI realm names
generated from the IMSI.		generated from the IMSI.
IANA has assigned the number 23 for EAP AKA authentication.		IANA has assigned the number 23 for EAP AKA authentication.
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specified:		specified:
AKA-Challenge...................................1		AKA-Challenge...................................1
AKA-Authentication-Reject.......................2		AKA-Authentication-Reject.......................2
AKA-Synchronization-Failure.....................4		AKA-Synchronization-Failure.....................4
AKA-Identity....................................5		AKA-Identity....................................5
AKA-Notification...............................12		AKA-Notification...............................12
AKA-Reauthentication...........................13		AKA-Reauthentication...........................13
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The Subtype-specific data is composed of attributes, which have		The Subtype-specific data is composed of attributes, which have
attribute type numbers. The following attribute types are specified:		attribute type numbers. The following attribute types are specified:
AT_RAND.........................................1		AT_RAND.........................................1
AT_AUTN.........................................2		AT_AUTN.........................................2
AT_RES..........................................3		AT_RES..........................................3
AT_AUTS.........................................4		AT_AUTS.........................................4
AT_PADDING......................................6		AT_PADDING......................................6
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AT_COUNTER_TOO_SMALL...........................20		AT_COUNTER_TOO_SMALL...........................20
AT_NONCE_S.....................................21		AT_NONCE_S.....................................21
AT_IV.........................................129		AT_IV.........................................129
AT_ENCR_DATA..................................130		AT_ENCR_DATA..................................130
AT_NEXT_PSEUDONYM.............................132		AT_NEXT_PSEUDONYM.............................132
AT_NEXT_REAUTH_ID.............................133		AT_NEXT_REAUTH_ID.............................133
All requests for value assignment from the various number spaces		All requests for value assignment from the various number spaces
described in this document require proper documentation, according		described in this document require proper documentation, according
to the "Specification Required" policy described in [15]. Requests		to the "Specification Required" policy described in [16]. Requests
must be specified in sufficient detail so that interoperability		must be specified in sufficient detail so that interoperability
between independent implementations is possible. Possible forms of		between independent implementations is possible. Possible forms of
documentation include, but are not limited to, RFCs, the products of		documentation include, but are not limited to, RFCs, the products of
another standards body (e.g. 3GPP), or permanently and readily		another standards body (e.g. 3GPP), or permanently and readily
available vendor design notes.		available vendor design notes.
12. Security Considerations		12. Security Considerations
The revised EAP base protocol [16] highlights several attacks that
		The revised EAP base protocol [17] highlights several attacks that
are possible against the EAP protocol. This section discusses the		are possible against the EAP protocol. This section discusses the
claimed security properties of EAP AKA as well as vulnerabilities		claimed security properties of EAP AKA as well as vulnerabilities
and security recommendations.		and security recommendations.
12.1. Identity Protection		12.1. Identity Protection
EAP/AKA includes optional Identity privacy support that protects the		EAP/AKA includes optional Identity privacy support that protects the
privacy of the subscriber identity against passive eavesdropping.		privacy of the subscriber identity against passive eavesdropping.
The mechanism cannot be used on the first connection with a given		The mechanism cannot be used on the first connection with a given
server, when the IMSI will have to be sent in the clear. The		server, when the IMSI will have to be sent in the clear. The
terminal SHOULD store the pseudonym in a non-volatile memory so that		terminal SHOULD store the pseudonym in a non-volatile memory so that
it can be maintained across reboots. An active attacker that		it can be maintained across reboots. An active attacker that
impersonates the network may use the AT_PERMANENT_ID_REQ attribute		impersonates the network may use the AT_PERMANENT_ID_REQ attribute
(Section 4.3) to learn the subscriber's IMSI. However, as discussed		(Section 4.3) to learn the subscriber's IMSI. However, as discussed
in Section 4.3, the terminal can refuse to send the cleartext IMSI		in Section 4.3, the terminal can refuse to send the cleartext IMSI
if it believes that the network should be able to recognize the		if it believes that the network should be able to recognize the
pseudonym.		pseudonym.
If the client and server cannot guarantee that the pseudonym will be
maintained reliably and Identity privacy is required then additional
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		If the client and server cannot guarantee that the pseudonym will be
		maintained reliably and Identity privacy is required then additional
protection from an external security mechanism such as Protected		protection from an external security mechanism such as Protected
Extensible Authentication Protocol (PEAP) [17] may be used. The		Extensible Authentication Protocol (PEAP) [18] may be used. The
benefits and the security considerations of using an external		benefits and the security considerations of using an external
security mechanism with EAP/AKA are beyond the scope of this		security mechanism with EAP/AKA are beyond the scope of this
document.		document.
12.2. Mutual Authentication		12.2. Mutual Authentication
EAP/AKA provides mutual authentication via the UMTS AKA mechanisms.		EAP/AKA provides mutual authentication via the UMTS AKA mechanisms.
12.3. Key Derivation		12.3. Key Derivation
EAP/AKA supports key derivation with 128-bit effective key strength.		EAP/AKA supports key derivation with 128-bit effective key strength.
The key hierarchy is specified in Section 10.		The key hierarchy is specified in Section 10.
The keys used to protect EAP AKA packets (K_encr, K_aut) and the		The Transient EAP Keys used to protect EAP AKA packets (K_encr,
application specific keys are cryptographically separate. An		K_aut) and the Master Session Keys are cryptographically separate.
attacker cannot derive any non-trivial information from K_encr or		An attacker cannot derive any non-trivial information from K_encr or
K_aut based on the application specific keys or vice versa. An		K_aut based on the Master Session Key or vice versa. An attacker
attacker also cannot calculate the pre-shared secret from the UMTS		also cannot calculate the pre-shared secret from the UMTS AKA IK,
AKA IK, UMTS AKA CK, EAP AKA K_encr, EAP AKA K_aut or from the		UMTS AKA CK, EAP AKA K_encr, EAP AKA K_aut or from the Master
application specific keys.		Session Key.
12.4. Brute-Force and Dictionary Attacks		12.4. Brute-Force and Dictionary Attacks
The effective strength of EAP/AKA values is 128 bits, and there are		The effective strength of EAP/AKA values is 128 bits, and there are
no known computationally feasible brute-force attacks. Because UMTS		no known computationally feasible brute-force attacks. Because UMTS
AKA is not a password protocol (the pre-shared secret must not be a		AKA is not a password protocol (the pre-shared secret must not be a
weak password), EAP/AKA is not vulnerable to dictionary attacks.		weak password), EAP/AKA is not vulnerable to dictionary attacks.
12.5. Integrity Protection, Replay Protection and Confidentiality		12.5. Integrity Protection, Replay Protection and Confidentiality
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to provide replay protection.		to provide replay protection.
The contents of the EAP-Response/Identity packet are implicitly		The contents of the EAP-Response/Identity packet are implicitly
integrity protected by including them in key derivation.		integrity protected by including them in key derivation.
Because EAP/AKA is not a tunneling method, EAP Notification, EAP		Because EAP/AKA is not a tunneling method, EAP Notification, EAP
Success or EAP Failure packets are not confidential, integrity		Success or EAP Failure packets are not confidential, integrity
protected or replay protected. On physically insecure networks, this		protected or replay protected. On physically insecure networks, this
may enable an attacker to mount denial of service attacks by sending		may enable an attacker to mount denial of service attacks by sending
false EAP Notification, EAP Success or EAP Failure packets. However,		false EAP Notification, EAP Success or EAP Failure packets. However,
the attacker cannot force the peers to believe successful		the attacker cannot force the peers to believe successful
authentication has occurred when mutual authentication failed or has
not happened yet.
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		authentication has occurred when mutual authentication failed or has
		not happened yet.
An eavesdropper will see the EAP Notification, EAP Success and EAP		An eavesdropper will see the EAP Notification, EAP Success and EAP
Failure packets sent in the clear. With EAP AKA, confidential		Failure packets sent in the clear. With EAP AKA, confidential
information MUST NOT be transmitted in EAP Notification packets.		information MUST NOT be transmitted in EAP Notification packets.
12.6. Negotiation Attacks		12.6. Negotiation Attacks
EAP/AKA does not protect the EAP-Response/Nak packet. Because		EAP/AKA does not protect the EAP-Response/Nak packet. Because
EAP/AKA does not protect the EAP method negotiation, EAP method		EAP/AKA does not protect the EAP method negotiation, EAP method
downgrading attacks may be possible, especially if the user uses the		downgrading attacks may be possible, especially if the user uses the
same identity with EAP/AKA and other EAP methods.		same identity with EAP/AKA and other EAP methods.
		As described in Section 6, EAP/AKA allows the protocol to be
		extended by defining new attribute types. When defining such
		attributes, it should be noted that any extra attributes included in
		EAP-Request/AKA-Identity or EAP-Response/AKA-Identity packets are
		not included in the MACs later on, and thus some other precautions
		must be taken to avoid modifications to them.
EAP/AKA does not support ciphersuite negotiation or EAP/AKA protocol		EAP/AKA does not support ciphersuite negotiation or EAP/AKA protocol
version negotiation.		version negotiation.
12.7. Fast Reconnect		12.7. Fast Reconnect
EAP/AKA includes an optional re-authentication ("fast reconnect")		EAP/AKA includes an optional re-authentication ("fast reconnect")
procedure, as recommended in [16] for EAP types that are intended		procedure, as recommended in [17] for EAP types that are intended
for physically insecure networks.		for physically insecure networks.
12.8. Acknowledged Result Indications		12.8. Acknowledged Result Indications
EAP/AKA does not provide acknowledged or integrity protected Success		EAP/AKA does not provide acknowledged or integrity protected Success
or Failure indications.		or Failure indications.
If an EAP Success or an EAP Failure packet is lost when using		If an EAP Success or an EAP Failure packet is lost when using
EAP/AKA over an unreliable medium, and if the protocol over which		EAP/AKA over an unreliable medium, and if the protocol over which
EAP/AKA is transported does not address the possible loss of Success		EAP/AKA is transported does not address the possible loss of Success
Skipping to change at page ?, line 2727 from start of file:
On physically insecure networks, an attacker may mount denial of		On physically insecure networks, an attacker may mount denial of
service attacks by sending false EAP Success or EAP Failure		service attacks by sending false EAP Success or EAP Failure
indications. However, the attacker cannot force the client or the		indications. However, the attacker cannot force the client or the
authenticator to believe successful authentication has occurred when		authenticator to believe successful authentication has occurred when
mutual authentication failed or has not happened yet.		mutual authentication failed or has not happened yet.
12.9. Man-in-the-middle Attacks		12.9. Man-in-the-middle Attacks
In order to avoid man-in-the-middle attacks and session hijacking,		In order to avoid man-in-the-middle attacks and session hijacking,
user data SHOULD be integrity protected on physically insecure		user data SHOULD be integrity protected on physically insecure
networks. The EAP/AKA application specific keys or keys derived from		networks. The EAP/AKA Master Session Key or keys derived from it MAY
them MAY be used as the integrity protection keys, or, if an		be used as the integrity protection keys, or, if an external
external security mechanism such as PEAP is used, then the link
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		security mechanism such as PEAP is used, then the link integrity
		protection keys MAY be derived by the external security mechanism.
There are man-in-the-middle attacks associated with the use of any		There are man-in-the-middle attacks associated with the use of any
EAP method within a tunneled protocol such as PEAP, or within a		EAP method within a tunneled protocol such as PEAP, or within a
sequence of EAP methods followed by each other. This specification		sequence of EAP methods followed by each other. This specification
does not address these attacks. If EAP/AKA is used with a tunneling		does not address these attacks. If EAP/AKA is used with a tunneling
protocol or as part of a sequence of methods, there should be		protocol or as part of a sequence of methods, there should be
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cryptographic binding provided between the protocols and EAP/AKA to		cryptographic binding provided between the protocols and EAP/AKA to
prevent man-in-the-middle attacks through rogue authenticators being		prevent man-in-the-middle attacks through rogue authenticators being
able to setup one-way authenticated tunnels. EAP/AKA application-		able to setup one-way authenticated tunnels. EAP/AKA Master Session
specific keys MAY be used to provide the cryptographic binding.		Key MAY be used to provide the cryptographic binding. However the
However the mechanism how the binding is provided depends on the		mechanism how the binding is provided depends on the tunneling or
tunneling or sequencing protocol, and it is beyond the scope of this		sequencing protocol, and it is beyond the scope of this document.
document.
12.10. Generating Random Numbers		12.10. Generating Random Numbers
An EAP/AKA implementation SHOULD use a good source of randomness to		An EAP/AKA implementation SHOULD use a good source of randomness to
generate the random numbers required in the protocol. Please see		generate the random numbers required in the protocol. Please see
[18] for more information on generating random numbers for security		[19] for more information on generating random numbers for security
applications.		applications.
13. Security Claims		13. Security Claims
This section provides the security claims required by [16].		This section provides the security claims required by [17].
[a] Intended use. EAP AKA is intended for use over both physically		[a] Intended use. EAP AKA is intended for use over both physically
insecure networks and physically or otherwise secure networks.		insecure networks and physically or otherwise secure networks.
Applicable media include but are not limited to PPP, IEEE 802 wired		Applicable media include but are not limited to PPP, IEEE 802 wired
networks and IEEE 802.11.		networks and IEEE 802.11.
[b] Mechanism. EAP AKA is based on the UMTS AKA mechanism, which is		[b] Mechanism. EAP AKA is based on the UMTS AKA mechanism, which is
an authentication and key agreement mechanism based on a symmetric		an authentication and key agreement mechanism based on a symmetric
128-bit pre-shared secret.		128-bit pre-shared secret.
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[f] Indication of vulnerabilities. Vulnerabilities are discussed in		[f] Indication of vulnerabilities. Vulnerabilities are discussed in
Section 12.		Section 12.
14. Intellectual Property Right Notices		14. Intellectual Property Right Notices
On IPR related issues, Nokia and Ericsson refer to the their		On IPR related issues, Nokia and Ericsson refer to the their
respective statements on patent licensing. Please see		respective statements on patent licensing. Please see
http://www.ietf.org/ietf/IPR/NOKIA and		http://www.ietf.org/ietf/IPR/NOKIA and
http://www.ietf.org/ietf/IPR/ERICSSON-General		http://www.ietf.org/ietf/IPR/ERICSSON-General
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Acknowledgements and Contributions		Acknowledgements and Contributions
The authors wish to thank Rolf Blom of Ericsson, Bernard Aboba of		The authors wish to thank Rolf Blom of Ericsson, Bernard Aboba of
Microsoft, Arne Norefors of Ericsson, N.Asokan of Nokia, Valtteri		Microsoft, Arne Norefors of Ericsson, N.Asokan of Nokia, Valtteri
Niemi of Nokia, Kaisa Nyberg of Nokia, Jukka-Pekka Honkanen of		Niemi of Nokia, Kaisa Nyberg of Nokia, Jukka-Pekka Honkanen of
Nokia, Olivier Paridaens of Alcatel and Ilkka Uusitalo of Ericsson		Nokia, Pasi Eronen of Nokia, Olivier Paridaens of Alcatel and Ilkka
for interesting discussions in this problem space.		Uusitalo of Ericsson for interesting discussions in this problem
		space.
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The attribute format is based on the extension format of Mobile IPv4		The attribute format is based on the extension format of Mobile IPv4
[19].		[20].
Authors' Addresses		Authors' Addresses
Jari Arkko		Jari Arkko
Ericsson		Ericsson
02420 Jorvas Phone: +358 40 5079256		02420 Jorvas Phone: +358 40 5079256
Finland Email: jari.arkko@ericsson.com		Finland Email: jari.arkko@ericsson.com
Henry Haverinen		Henry Haverinen
Nokia Mobile Phones		Nokia Mobile Phones
P.O. Box 88		P.O. Box 88
33721 Tampere Phone: +358 50 594 4899		33721 Tampere Phone: +358 50 594 4899
Finland E-mail: henry.haverinen@nokia.com		Finland E-mail: henry.haverinen@nokia.com
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Annex A. Pseudo-Random Number Generator		Annex A. Pseudo-Random Number Generator
The "|" character denotes concatenation, and "^" denotes involution.		The "|" character denotes concatenation, and "^" denotes involution.
Step 1: Choose a new, secret value for the seed-key, XKEY		Step 1: Choose a new, secret value for the seed-key, XKEY
Step 2: In hexadecimal notation let		Step 2: In hexadecimal notation let
t = 67452301 EFCDAB89 98BADCFE 10325476 C3D2E1F0		t = 67452301 EFCDAB89 98BADCFE 10325476 C3D2E1F0
This is the initial value for H0|H1|H2|H3|H4		This is the initial value for H0|H1|H2|H3|H4
in the FIPS SHS [12]		in the FIPS SHS [12]
Step 3: For j = 0 to m û 1 do		Step 3: For j = 0 to m - 1 do
3.1 XSEED_j = optional user input		3.1 XSEED_j = optional user input
3.2 For i = 0 to 1 do		3.2 For i = 0 to 1 do
a. XVAL = (XKEY + XSEED_j) mod 2^b		a. XVAL = (XKEY + XSEED_j) mod 2^b
b. w_i = G(t, XVAL)		b. w_i = G(t, XVAL)
c. XKEY = (1 + XKEY + w_i) mod 2^b		c. XKEY = (1 + XKEY + w_i) mod 2^b
3.3 x_j = w_0|w_1		3.3 x_j = w_0|w_1
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References		References
[1] 3GPP Technical Specification 3GPP TS 33.102 V3.6.0: "Technical		[1] 3GPP Technical Specification 3GPP TS 33.102 V5.1.0: "Technical
Specification Group Services and System Aspects; 3G Security;		Specification Group Services and System Aspects; 3G Security;
Security Architecture (Release 1999)", 3rd Generation		Security Architecture (Release 5)", 3rd Generation Partnership
Partnership Project, November 2000. (NORMATIVE)		Project, December 2002. (NORMATIVE)
[2] IEEE P802.1X/D11, "Standards for Local Area and Metropolitan		[2] IEEE P802.1X/D11, "Standards for Local Area and Metropolitan
Area Networks: Standard for Port Based Network Access		Area Networks: Standard for Port Based Network Access
Control", March 2001. (INFORMATIVE)		Control", March 2001. (INFORMATIVE)
[3] IEEE Draft 802.11eS/D1, "Draft Supplement to STANDARD FOR		[3] IEEE Draft 802.11eS/D1, "Draft Supplement to STANDARD FOR
Telecommunications and Information Exchange between Systems -		Telecommunications and Information Exchange between Systems -
LAN/MAN Specific Requirements - Part 11: Wireless Medium		LAN/MAN Specific Requirements - Part 11: Wireless Medium
Access Control (MAC) and physical layer (PHY) specifications:		Access Control (MAC) and physical layer (PHY) specifications:
Specification for Enhanced Security", March 2001.		Specification for Enhanced Security", March 2001.
Skipping to change at page ?, line 2879 from start of file:
[4] Aboba, B. and M. Beadles, "The Network Access Identifier", RFC		[4] Aboba, B. and M. Beadles, "The Network Access Identifier", RFC
2486, January 1999. (NORMATIVE)		2486, January 1999. (NORMATIVE)
[5] L. Blunk, J. Vollbrecht, "PPP Extensible Authentication		[5] L. Blunk, J. Vollbrecht, "PPP Extensible Authentication
Protocol (EAP)", RFC 2284, March 1998. (NORMATIVE)		Protocol (EAP)", RFC 2284, March 1998. (NORMATIVE)
[6] S. Bradner, "Key words for use in RFCs to indicate Requirement		[6] S. Bradner, "Key words for use in RFCs to indicate Requirement
Levels", RFC 2119, March 1997. (NORMATIVE)		Levels", RFC 2119, March 1997. (NORMATIVE)
[7] GSM Technical Specification GSM 03.03 (ETS 300 523): "Digital		[7] 3GPP Technical Specification 3GPP TS 23.003 V5.5.1: "3rd
cellular telecommunication system (Phase 2); Numbering,		Generation Parnership Project; Technical Specification Group
addressing and identification", European Telecommunications		Core Network; Numbering, addressing and identification
Standards Institute, April 1997. (NORMATIVE)		(Release 5)", 3rd Generation Parnership Project, January 2003
		(NORMATIVE)
[8] Draft 3GPP Technical Specification 3GPP TS 23.234 V 1.2.0:		[8] Draft 3GPP Technical Specification 3GPP TS 23.234 V 1.4.0:
"Technical Specification Group Services and System Aspects;		"Technical Specification Group Services and System Aspects;
3GPP system to Wireless Local Area Network (WLAN)		3GPP system to Wireless Local Area Network (WLAN)
Interworking; System Description", 3rd Generation Partnership		Interworking; System Description", 3rd Generation Partnership
Project, work in progress, November 2002. (INFORMATIVE)		Project, work in progress, January 2003. (INFORMATIVE)
[9] H. Krawczyk, M. Bellare, R. Canetti, "HMAC: Keyed-Hashing for		[9] H. Krawczyk, M. Bellare, R. Canetti, "HMAC: Keyed-Hashing for
Message Authentication", RFC2104, February 1997. (NORMATIVE)		Message Authentication", RFC2104, February 1997. (NORMATIVE)
[10] Federal Information Processing Standard (FIPS) draft standard,		[10] Federal Information Processing Standard (FIPS) draft standard,
"Advanced Encryption Standard (AES)",		"Advanced Encryption Standard (AES)",
http://csrc.nist.gov/publications/drafts/dfips-AES.pdf,		http://csrc.nist.gov/publications/drafts/dfips-AES.pdf,
September 2001. (NORMATIVE)		September 2001. (NORMATIVE)
[11] US National Bureau of Standards, "DES Modes of Operation",		[11] US National Bureau of Standards, "DES Modes of Operation",
Federal Information Processing Standard (FIPS) Publication 81,		Federal Information Processing Standard (FIPS) Publication 81,
December 1980. (NORMATIVE)		December 1980. (NORMATIVE)
Arkko and Haverinen Expires in six months [Page 55]		Arkko and Haverinen Expires in six months [Page 55]
EAP AKA Authentication January 2003
		EAP AKA Authentication February 2003
[12] 3GPP Technical Specification 3GPP TS 33.105 V3.5.0: "Technical
		[12] 3GPP Technical Specification 3GPP TS 33.105 4.1.0: "Technical
Specification Group Services and System Aspects; 3G Security;		Specification Group Services and System Aspects; 3G Security;
Cryptographic Algorithm Requirements (Release 1999)",		Cryptographic Algorithm Requirements (Release 4)", 3rd
3rdGeneration Partnership Project, October 2000 (NORMATIVE)		Generation Partnership Project, June 2001 (NORMATIVE)
[13] Federal Information Processing Standards (FIPS) Publication		[13] Federal Information Processing Standards (FIPS) Publication
186-2 (with change notice), "Digital Signature Standard		186-2 (with change notice), "Digital Signature Standard
(DSS)", National Institute of Standards and Technology,		(DSS)", National Institute of Standards and Technology,
January 27, 2000, (NORMATIVE)		January 27, 2000, (NORMATIVE)
Available on-line at:		Available on-line at:
http://csrc.nist.gov/publications/fips/fips186-2/		http://csrc.nist.gov/publications/fips/fips186-2/
fips186-2-change1.pdf		fips186-2-change1.pdf
[14] G. Zorn, "Microsoft Vendor-specific RADIUS Attributes", RFC		[14] B. Aboba, D. Simon, "PPP EAP TLS Authentication Protocol", RFC
		2716, October 1999 (INFORMATIVE)
		[15] G. Zorn, "Microsoft Vendor-specific RADIUS Attributes", RFC
2548, March 1999 (INFORMATIVE)		2548, March 1999 (INFORMATIVE)
[15] T. Narten, H. Alvestrand, "Guidelines for Writing an IANA		[16] T. Narten, H. Alvestrand, "Guidelines for Writing an IANA
Considerations Section in RFCs", RFC 2434, October 1998.		Considerations Section in RFCs", RFC 2434, October 1998.
(NORMATIVE)		(NORMATIVE)
[16] L. Blunk, J. Vollbrecht, B. Aboba, "Extensible Authentication		[17] L. Blunk, J. Vollbrecht, B. Aboba, "Extensible Authentication
Protocol (EAP)", draft-ietf-pppext-rfc2284bis-07.txt, work-in-		Protocol (EAP)", draft-ietf-pppext-rfc2284bis-07.txt, work-in-
progress, October 2002. (NORMATIVE)		progress, October 2002. (NORMATIVE)
[17] H. Andersson, S. Josefsson, G. Zorn, D. Simon, A. Palekar,		[18] H. Andersson, S. Josefsson, G. Zorn, D. Simon, A. Palekar,
"Protected EAP Protocol (PEAP)", draft-josefsson-pppext-eap-		"Protected EAP Protocol (PEAP)", draft-josefsson-pppext-eap-
tls-eap-05.txt, work-in-progress, September 2002.		tls-eap-05.txt, work-in-progress, September 2002.
(IMFORMATIVE)		(IMFORMATIVE)
[18] D. Eastlake, 3rd, S. Crocker, J. Schiller, "Randomness		[19] D. Eastlake, 3rd, S. Crocker, J. Schiller, "Randomness
Recommendations for Security", RFC 1750 (Informational),		Recommendations for Security", RFC 1750 (Informational),
December 1994. (INFORMATIVE)		December 1994. (INFORMATIVE)
[19] C. Perkins (editor), "IP Mobility Support", RFC 2002, October		[20] C. Perkins (editor), "IP Mobility Support", RFC 3344, August
1996. (INFORMATIVE)		2002. (INFORMATIVE)
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