Network Working Group S. Rowles
Internet-Draft A. Yeung, Ed.
Intended status: Standards Track P. Tran
Expires: April 17, 2015 Cisco Systems
Y. Nir
Check Point Software Technologies Ltd.
October 14, 2014
Group Key Management using IKEv2
draft-yeung-g-ikev2-08
Abstract
This document presents a new group key distribution protocol. The
protocol is in conformance with MSEC key management architecture it
contains two components: member registration and group rekeying, both
downloading group security associations from the Group Controller Key
Server to a member of the group. The new protocol is similar to
IKEv2 in message and payload formats as well as message semantics.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 17, 2015.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
Rowles, et al. Expires April 17, 2015 [Page 1]
Internet-Draft G-IKEv2 October 2014
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction and Overview . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Why do we need another GSA protocol? . . . . . . . . . . 4
1.3. G-IKEv2 Payloads . . . . . . . . . . . . . . . . . . . . 4
2. G-IKEv2 integration into IKEv2 protocol . . . . . . . . . . . 4
2.1. UDP port . . . . . . . . . . . . . . . . . . . . . . . . 5
3. G-IKEv2 Protocol . . . . . . . . . . . . . . . . . . . . . . 5
3.1. G-IKEv2 member registration and secure channel
establishment . . . . . . . . . . . . . . . . . . . . . . 5
3.1.1. GSA_AUTH exchange . . . . . . . . . . . . . . . . . . 6
3.1.2. GSA_REGISTRATION Exchange . . . . . . . . . . . . . . 7
3.1.3. IKEv2 Header Initialization . . . . . . . . . . . . . 7
3.1.4. GM Registration Operations . . . . . . . . . . . . . 7
3.1.5. GCKS Registration Operations . . . . . . . . . . . . 8
3.2. Counter-based modes of operation . . . . . . . . . . . . 9
3.3. G-IKEv2 group maintenance channel . . . . . . . . . . . . 11
3.3.1. G-IKEv2 GSA_REKEY exchange . . . . . . . . . . . . . 11
3.3.2. Forward and Backward Access Control . . . . . . . . . 12
3.3.3. Forward Access Control Requirements . . . . . . . . . 13
3.3.4. Deletion of SAs . . . . . . . . . . . . . . . . . . . 13
3.3.5. GSA_REKEY GCKS Operations . . . . . . . . . . . . . . 14
3.3.6. GSA_REKEY GM Operations . . . . . . . . . . . . . . . 14
4. Header and Payload Formats . . . . . . . . . . . . . . . . . 15
4.1. The G-IKEv2 Header . . . . . . . . . . . . . . . . . . . 15
4.2. Group Identification (IDg) Payload . . . . . . . . . . . 15
4.3. Group Security Association Payload . . . . . . . . . . . 16
4.3.1. GSA policy . . . . . . . . . . . . . . . . . . . . . 16
4.4. KEK Policy . . . . . . . . . . . . . . . . . . . . . . . 17
4.4.1. KEK Attributes . . . . . . . . . . . . . . . . . . . 18
4.4.2. KEK_MANAGEMENT_ALGORITHM . . . . . . . . . . . . . . 19
4.4.3. KEK_ENCR_ALGORITHM . . . . . . . . . . . . . . . . . 19
4.4.4. KEK_KEY_LENGTH . . . . . . . . . . . . . . . . . . . 19
4.4.5. KEK_KEY_LIFETIME . . . . . . . . . . . . . . . . . . 20
4.4.6. KEK_INTEGRITY_ALGORITHM . . . . . . . . . . . . . . . 20
4.4.7. KEK_AUTH_METHOD . . . . . . . . . . . . . . . . . . . 20
4.4.8. KEK_AUTH_ALGORITHM . . . . . . . . . . . . . . . . . 20
4.4.9. KEK_MESSAGE_ID . . . . . . . . . . . . . . . . . . . 20
4.5. GSA TEK Policy . . . . . . . . . . . . . . . . . . . . . 20
4.5.1. TEK ESP and AH Protocol-Specific Policy . . . . . . . 21
4.6. GSA Group Associated Policy . . . . . . . . . . . . . . . 23
4.6.1. ACTIVATION_TIME_DELAY/DEACTIVATION_TIME_DELAY . . . . 24
Rowles, et al. Expires April 17, 2015 [Page 2]
Internet-Draft G-IKEv2 October 2014
4.7. Key Download Payload . . . . . . . . . . . . . . . . . . 24
4.7.1. TEK Download Type . . . . . . . . . . . . . . . . . . 26
4.7.2. KEK Download Type . . . . . . . . . . . . . . . . . . 27
4.7.3. LKH Download Type . . . . . . . . . . . . . . . . . . 28
4.7.4. SID Download Type . . . . . . . . . . . . . . . . . . 31
4.8. Delete Payload . . . . . . . . . . . . . . . . . . . . . 33
4.9. Notify Payload . . . . . . . . . . . . . . . . . . . . . 33
4.10. Authentication Payload . . . . . . . . . . . . . . . . . 34
5. Security Considerations . . . . . . . . . . . . . . . . . . . 34
5.1. GSA registration and secure channel . . . . . . . . . . . 34
5.2. GSA maintenance channel . . . . . . . . . . . . . . . . . 34
5.2.1. Authentication/Authorization . . . . . . . . . . . . 34
5.2.2. Confidentiality . . . . . . . . . . . . . . . . . . . 35
5.2.3. Man-in-the-Middle Attack Protection . . . . . . . . . 35
5.2.4. Replay/Reflection Attack Protection . . . . . . . . . 35
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35
6.1. New registries . . . . . . . . . . . . . . . . . . . . . 35
6.2. New payload and exchange types to existing IKEv2 registry 36
6.3. New Name spaces . . . . . . . . . . . . . . . . . . . . . 36
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 36
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 36
8.1. Normative References . . . . . . . . . . . . . . . . . . 36
8.2. Informative References . . . . . . . . . . . . . . . . . 37
Appendix A. Differences between G-IKEv2 and RFC 6407 . . . . . . 38
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38
1. Introduction and Overview
This document presents a group key management protocol protected by
IKEv2. The data communications within the group are protected by a
key pushed to the group members (GMs) by the Group Controller/Key
Server (GCKS) using IKEv2 [RFC5996]. The GCKS pushes policy and keys
for the group to the GM after authenticating it using new payloads
added in the IKE_AUTH exchange. This document references IKEv2
[RFC5996] but it intended to be a separate document. GDOI update
document [RFC6407] presented GDOI using IKEv1 syntax. This document
uses IKEv2 syntax. The message semantics of IKEv2 are preserved, in
that all communications consists of message request-response pairs.
The exception to this rule are the rekeying messages, which are sent
in multicast without a response. A number of payloads were deemed
unnecessary since [RFC6407] are described in Appendix A
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Rowles, et al. Expires April 17, 2015 [Page 3]
Internet-Draft G-IKEv2 October 2014
1.2. Why do we need another GSA protocol?
GDOI protocol specified in [RFC6407] is protected by IKEv1 phase1
security association defined in [RFC2407], [RFC2408] and [RFC2409];
these documents are obsoleted and replaced by a new version of the
IKE protocol defined in RFC 5996. G-IKEv2 provides group key
management between the group member and group controller key server
using the new IKEv2 protocol and inherits the following key
advantages over GDOI:
1. Provide a simple mechanism for the responder to keep minimal
state and avoid DOS attack from forged IP address using cookie
challenge exchange.
2. Improve performance and network latency by the reduced number of
initial messages to complete the G-IKEv2 protocol from (10
messages in main mode and quick mode, 7 messages in aggressive
mode and quick) to 4 messages.
3. Fix cryptographic weakness with authentication HASH (ikev1
authentication HASH specified in RFC-2409 does not include all
ISAKMP payloads and does not include ISAKMP header). This issue
is documented at [IKE-HASH].
4. Improve protocol reliability where all unicast messages are
ack'ed and sequenced.
5. Well defined behavior for error conditions to improve
interoperability.
1.3. G-IKEv2 Payloads
1. IDg (group ID) - The GM requests the GCKS for membership into the
group by sending its IDg payload.
2. GSA (Group Security Association) - The GCKS sends the group
policy to the GM using this payload.
3. KD (Key Download) - The GCKS sends the control and data keys to
the GM using the KD payload.
2. G-IKEv2 integration into IKEv2 protocol
The G-IKEv2 protocol provides the security mechanisms of IKEv2 (peer
authentication, confidentiality, message integrity) to protect the
group negotiations required for G-IKEv2. The G-IKEv2 exchange
further provides group authorization, and secure policy and key
download from the GCKS to its group members.
Rowles, et al. Expires April 17, 2015 [Page 4]
Internet-Draft G-IKEv2 October 2014
2.1. UDP port
G-IKEv2 SHOULD use port 848, the same as GDOI [RFC6407] , because
they serve a similar function, and can use the same ports, just as
IKEv1 and IKEv2 can share port 500. The version number in the IKEv2
header distinguishes the G-IKEv2 protocol from GDOI protocol
[RFC6407].
3. G-IKEv2 Protocol
3.1. G-IKEv2 member registration and secure channel establishment
The registration protocol consists of minimum two exchanges
IKE_SA_INIT and GSA_AUTH; member registration may have a few more
messages exchanged if the EAP method, cookie challenge (for DoS) or
invalid KE are used. Each exchange consists of request/response
pairs. The first exchange IKE_SA_INIT is defined in IKEv2 [RFC5996].
This exchange negotiates cryptographic algorithms, exchanges nonces
and does a Diffie-Hellman exchange between the member and the Group
Controller Key Server (GCKS).
The second exchange GSA_AUTH authenticates the previous messages,
exchange identities and certificates. These messages are encrypted
and integrity protected with keys established through the IKE_SA_INIT
exchange, so the identities are hidden from eavesdroppers and all
fields in all the messages are authenticated. The GCKS MAY authorize
group members to be allowed into the group as part of the GSA_AUTH
exchange. Once the GCKS accepted a group member to join a group it
may downloads the data security keys (TEKs) and/or group key
encrypting key (KEK) or KEK array as part of GSA_AUTH response
message. In the following descriptions, the payloads contained in
the message are indicated by names as listed below.
Notation Payload
------------------------------------------------------------
AUTH Authentication
CERT Certificate
CERTREQ Certificate Request
GSA Group Security Association
HDR IKEv2 Header
IDg Identification - Group
IDi Identification - Initiator
IDr Identification - Responder
KD Key Download
KE Key Exchange
Ni, Nr Nonce SA Security Association
Rowles, et al. Expires April 17, 2015 [Page 5]
Internet-Draft G-IKEv2 October 2014
The details of the contents of each payload are described in
Section 4. Payloads that may optionally appear will be shown in
brackets, such as [CERTREQ], indicate that optionally a certificate
request payload can be included.
3.1.1. GSA_AUTH exchange
After the group member and GCKS uses IKE_SA_INIT exchange to
negotiate cryptographic algorithms, exchange nonces, and perform a
Diffie-Hellman exchange as defined in IKEv2 [RFC5996], the IKE_AUTH
or GSA_AUTH MUST complete before any other exchanges can be done.
The security properties of the GSA_AUTH exchange are the same as the
properties of the IKE_AUTH exchange. It is used to authenticate the
IKE_SA_INIT messages, exchange identities and certificates. G-IKEv2
also uses this exchange for group member registration and optionally
authorization. GSA_AUTH does not include SA2, TSi and TSr since
policy is not negotiated between group member and GCKS but downloaded
from the GCKS to the group member.
Initiator (Member) Responder (GCKS)
-------------------- ------------------
HDR, SK { IDi, [CERT,] [CERTREQ,] [IDr,] AUTH,
IDg, [N] } -->
After an unauthenticated secure channel is established by IKE_SA_INIT
exchange, the member initiates a registration request to join a group
indicated by the IDg payload. The GM MAY include the Notify payload
status type SENDER_ID_REQUEST to request SIDs for Counter-based
cipher from the GCKS.
<-- HDR, SK { IDr, [CERT,] AUTH, [GSA, KD,] [D,] }
Besides response with IDr, optional CERT, and AUTH material, the GCKS
MAY also informs the member the cryptographic policies of the group
in the GSA payload and key material in the KD payload. GCKS can also
include Delete payload instructing the group member to delete
existing SAs it might have.
In addition to the IKEv2 error handling, GCKS can reject the
registration request when IDg is invalid or authorization fail, etc.
In these cases, see Section 4.9, the GSA_AUTH response will include
notify indicate errors. The member MUST delete the registration IKE
SA.
Initiator (Member) Responder (GCKS)
-------------------- ------------------
<-- HDR, SK { N }
Rowles, et al. Expires April 17, 2015 [Page 6]
Internet-Draft G-IKEv2 October 2014
When the group member found the policy sent by the GCKS is
unacceptable, the member SHOULD send an IKEv2 delete using the
INFORMATION message exchange to bring down the authenticated IKE SA.
3.1.2. GSA_REGISTRATION Exchange
When a secure channel is already established between GM and KS, the
GM registration for a group can reuse the established secure channel.
In this scenario the GM will use the GSA_REGISTRATION exchange by
including the desired group ID (IDg) to request data security keys
(TEKs) and/or group key encrypting keys (KEKs) from the GCKS. The GM
MAY also include the Notify payload status type SENDER_ID_REQUEST to
request SIDs for Counter-based cipher from the GCKS.
Initiator (Member) Responder (GCKS)
-------------------- ------------------
HDR, SK {IDg, [N] } -->
<-- HDR, SK { GSA, KD, [D] }
This exchange can also be used when the group member found the policy
sent by the GCKS is unacceptable. The group member can notify the
GCKS by sending IDg and the NOTIFY type NO_PROPOSAL_CHOSEN as shown
below. The GCKS MUST unregister the group member.
Initiator (Member) Responder (GCKS)
-------------------- ------------------
HDR, SK {IDg [N,]} -->
<-- HDR, SK {}
3.1.3. IKEv2 Header Initialization
The Major Version is (2) and Minor Version number (0) according to
IKEv2 [RFC5996], and maintained in this document. The G-IKEv2
IKE_SA_INIT, GSA_AUTH and GSA_REGISTRATION use the SPI according to
IKEv2 [RFC5996],section 2.6.
3.1.4. GM Registration Operations
A G-IKEv2 Initiator (GM) requesting registration contacts the GCKS
using the IKE_SA_INIT exchange and receives the response from the
GCKS. This exchange is unchanged from the IKE_SA_INIT in IKEv2
protocol.
Upon completion of parsing and verifying the IKE_SA_INIT response,
the GM sends the GSA_AUTH message with the IKEv2 payloads from
IKE_AUTH (without the SAi2, TSi and TSr) along with the Group ID
Rowles, et al. Expires April 17, 2015 [Page 7]
Internet-Draft G-IKEv2 October 2014
informing the GCKS of the group the initiator wishes to join. The
initiator MAY specify how many Sender-ID values it would like to
receive in the Notify payload status type SENDER_ID_REQUEST in case
the Data Security SA supports a counter mode cipher [section 3.2].
Upon receiving the GSA_AUTH, the initiator then parses the response
from the GCKS authenticating the exchange using the IKEv2 method,
then processing the GSA, and KD.
The GSA payload contains the security protocol and cryptographic
protocols used by the group. This policy describes the Re-key SA
(KEK), if present, Data-security SAs (TEK), and other group policy
(GAP). If the policy in the GSA payload is not acceptable to the GM,
it SHOULD tear down the session after notifying the GCKS. Finally
the KD is parsed providing the keying material for the TEK and/or
KEK. The GM interprets the KD key packets, where each key packet
includes the keying material for SAs distributed in the GSA payload.
Keying material is matched by comparing the SPIs in the key packets
to SPIs previously included in the GSA payloads. Once TEK keys and
policy are matched, the GM provides them to the data security
subsystem, and it is ready to send or receive packets matching the
TEK policy.
The GSA KEK policy MUST include KEK attribute KEK_MESSAGE_ID with a
message id. The message id in the KEK_MESSAGE_ID attribute MUST be
checked against any previously received message id for this group.
If it is less than the previously received number, it should be
considered stale and ignored. This could happen if two GSA_AUTH
exchanges happened in parallel, and the message id changed. This
KEK_MESSAGE_ID is used by the GM to prevent GSA_REKEY message replay
attacks. The first GSA_REKEY message that the GM receives from the
GCKS has to have message id greater or equal to the message id
received in the KEK_MESSAGE_ID attribute.
3.1.5. GCKS Registration Operations
A G-IKEv2 GCKS passively listens for incoming requests from group
members. The GCKS receives the IKE_SA_INIT request, select the IKE
proposal, generates nonce and DH to include them in the IKE_SA_INIT
response.
Upon receiving the GSA_AUTH request, and after authenticate the group
member using the same properties as IKEv2, the GCKS locates the group
the GM wishes to join, extracts the policy for that group. If the
GCKS policy desires authorization, the GCKS authorizes the group
member against the specified credentials before preparing to send
GSA_AUTH response. The GSA_AUTH response MAY include group policy in
GSA payload and keys in the KD payload. If the GCKS policy include
Rowles, et al. Expires April 17, 2015 [Page 8]
Internet-Draft G-IKEv2 October 2014
group rekey option, this policy is constructed in the GSA KEK and the
key is constructed in the KD KEK. The GSA KEK MUST include attribute
KEK_MESSAGE_ID specify the starting message id the GCKS will be using
when sending the GSA_REKEY message to the group member. This message
id is used prevent replay attacks of the GSA_REKEY message and will
be increasing each time a GSA_REKEY message is sent to the group.
The GCKS data traffic policy is included in the GSA TEK and keys are
included in KD TEK. GSA GAP MAY also included to provide the ATD
and/or DTD [section 4.6.1] specifying activation and deactivation
delays for SAs generated from the TEKs. If one or more Data Security
SAs distributed in the GSA payload included a counter mode of
operation, the GCKS includes at least one SID value in the KD
payload, and possibly more depending on the request received in the
NOTIFY payload status type SENDER_ID_REQUEST requesting the number of
SIDs from the group member.
If the GCKS receives a GSA_REGISTRATION exchange with a request to
register a GM to a group, the GCKS will need to authorize the GM with
the new group (IDg) and respond with corresponding group policy and
keys. If the GCKS fails to authorize the GM, it will respond with
the AUTHORIZATION_FAILED notify message.
3.2. Counter-based modes of operation
Several new counter-based modes of operation have been specified for
ESP (e.g., AES-CTR [RFC3686], AES-GCM [RFC4106], AES-CCM [RFC4309],
AES-GMAC [RFC4543]) and AH (e.g., AES-GMAC [RFC4543]). These
counter-based modes require that no two senders in the group ever
send a packet with the same Initialization Vector (IV) using the same
cipher key and mode. This requirement is met in G-IKEv2 when the
following requirements are met:
o The GCKS distributes a unique key for each Data-Security SA.
o The GCKS uses the method described in [RFC6054], which assigns each
sender a portion of the IV space by provisioning each sender with one
or more unique SID values.
When at least one Data-Security SA included in the group policy
includes a counter-mode, the GCKS automatically allocates and
distributes one SID to each group member acting in the role of sender
on the Data-Security SA. The SID value is used exclusively by the
group member to which it was allocated. The group member uses the
same SID for each Data-Security SA specifying the use of a counter-
based mode of operation. A GCKS MUST distribute unique keys for each
Data-Security SA including a counter-based mode of operation in order
to maintain a unique key and nonce usage.
Rowles, et al. Expires April 17, 2015 [Page 9]
Internet-Draft G-IKEv2 October 2014
During registration, the group member can choose to request one or
more SID values. Requesting a value of 1 is not necessary since the
GCKS will automatically allocate exactly one to the sending group
member. A group member MUST request as many SIDs matching the number
of encryption modules in which it will be installing the TEKs in the
outbound direction. Alternatively, a group member MAY request more
than one SID and use them serially. This could be useful when it is
anticipated that the group member will exhaust their range of Data-
Security SA nonces using a single SID too quickly (e.g., before the
time-based policy in the TEK expires).
When group policy includes a counter-based mode of operation, a GCKS
SHOULD use the following method to allocate SID values, which ensures
that each SID will be allocated to just one group member.
1. A GCKS maintains an SID-counter, which records the SIDs that have
been allocated. SIDs are allocated sequentially, with the first SID
allocated to be zero.
2. Each time an SID is allocated, the current value of the counter
is saved and allocated to the group member. The SID-counter is then
incremented in preparation for the next allocation.
3. When the GCKS specifies a counter-based mode of operation in the
Data Security SA, and a group member is a sender, a group member may
request a count of SIDs during registration in a NOTIFY payload
information type SEND_ID_REQUEST. When the GCKS receives this
request, it increments the SID- counter once for each requested SID,
and distributes each SID value to the group member.
4. A GCKS allocates new SID values for each GSA_REGISTRATION
exchange originated by a sender, regardless of whether a group member
had previously contacted the GCKS. In this way, the GCKS does not
have a requirement of maintaining a record of which SID values it had
previously allocated to each group member. More importantly, since
the GCKS cannot reliably detect whether the group member had sent
data on the current group Data-Security SAs it does not know what
Data-Security counter-mode nonce values that a group member has used.
By distributing new SID values, the key server ensures that each time
a conforming group member installs a Data- Security SA it will use a
unique set of counter-based mode nonces.
5. When the SID-counter maintained by the GCKS reaches its final SID
value, no more SID values can be distributed. Before distributing
any new SID values, the GCKS MUST delete the Data- Security SAs for
the group, followed by creation of new Data- Security SAs, and
resetting the SID-counter to its initial value.
Rowles, et al. Expires April 17, 2015 [Page 10]
Internet-Draft G-IKEv2 October 2014
6. The GCKS SHOULD send a GSA_REKEY message deleting all Data-
Security SAs and the Rekey SA for the group. This will result in the
group members initiating a new GSA_REGISTRATION exchange, in which
they will receive both new SID values and new Data-Security SAs. The
new SID values can safely be used because they are only used with the
new Data-Security SAs. Note that deletion of the Rekey SA is
necessary to ensure that group members receiving a GSA_REKEY exchange
before the re-register do not inadvertently use their old SIDs with
the new Data-Security SAs. Using the method above, at no time can
two group members use the same IV values with the same Data-Security
SA key.
3.3. G-IKEv2 group maintenance channel
The GCKS indicates that it will be delivering group rekey messages
when the KEK policy and keys are present in the G-IKEv2 GSA and KD
payloads. Though the G-IKEv2 Rekey is optional, it plays a crucial
role for large and dynamic groups. The GCKS is responsible for
rekeying of the secure group per the group policy. The GCKS uses
multicast to transport the rekey message. The G-IKEv2 protocol uses
GSA_REKEY exchange type in G-IKEv2 header identifying it as a rekey
message. This rekey message is protected by the registration
exchanges.
3.3.1. G-IKEv2 GSA_REKEY exchange
The GCKS initiates the G-IKEv2 Rekey securely using IP multicast.
Since multicast rekey does not require a response and it sends to
multiple GMs, G-IKEv2 rekeying MUST NOT support windowing. The GCKS
rekey message replaces the rekey GSA KEK or KEK array, and/or creates
a new Data-Security GSA TEK. The SID Download attribute [section
4.7.4] in the Key Download payload MUST NOT be part of the Rekey
Exchange as this is sender specific information and the Rekey
Exchange is group specific. The GCKS initiates the GSA_REKEY
exchange as following:
Members (Responder) GCKS (Initiator)
-------------------- ------------------
<-- HDR, SK {GSA, KD, [D,] AUTH }
HDR is defined in Section 4.1. The message id in this message will
start with the same value the GCKS sent to group member in the KEK
attribute KEK_MESSAGE_ID during registration; this message id will be
increasing each time a new GSA_REKEY message is sent to the group
members.
Rowles, et al. Expires April 17, 2015 [Page 11]
Internet-Draft G-IKEv2 October 2014
The GSA payload contains the current rekey and data security SAs.
The GSA may contain a new data security SA and/or a new rekey SA,
which, optionally contains an LKH rekey SA, Section 4.3.
The KD represents the keys for the policy included in the GSA. If
the data security SA is being refreshed in this rekey message, the
IPsec keys are updated in the KD, and/or if the rekey SA is being
refreshed in this rekey message, the rekey Key or the LKH KEK array
is updated in the KD payload.
The Delete payload is included to instruct the GM to delete existing
SAs.
The AUTH payload is included to authenticate GSA_REKEY message using
any of the authentication methods define by IKEv2 section 3.8.
Shared Key Integrity Code SHOULD NOT be used as it doesn't provide
source origin authentication (although a small group may not require
source origin authentication). During group member registration, the
GCKS sends the authentication key in the GSAK payload KEK_AUTH_KEY
attribute, which the group member uses to authenticate the key
server. Before the current Authentication Key expires, GCKS will
send a new KEK_AUTH_KEY to its group member in GSA_REKEY message.
The AUTH key that is used in the rekey message may not be the same as
the authentication key used in GSA_AUTH. Typically rekey message is
sent as multicast and receive by all group members, the same AUTH key
is distributed to all group members.
After adding the AUTH payload to the rekey message, the current KEK
encryption key encrypts all payloads following the HDR.
3.3.2. Forward and Backward Access Control
Through G-IKEv2 rekey, the G-IKEv2 supports algorithms such as LKH
that have the property of denying access to a new group key by a
member removed from the group (forward access control) and to an old
group key by a member added to the group (backward access control).
An unrelated notion to PFS, "forward access control" and "backward
access control" have been called "perfect forward security" and
"perfect backward security" in the literature [RFC2627].
Group management algorithms providing forward and backward access
control other than LKH have been proposed in the literature,
including OFT [OFT] and Subset Difference [NNL]. These algorithms
could be used with G-IKEv2, but are not specified as a part of this
document.
Support for group management algorithms is supported via the
KEY_MANAGEMENT_ALGORITHM attribute which is sent in the GSA KEK
Rowles, et al. Expires April 17, 2015 [Page 12]
Internet-Draft G-IKEv2 October 2014
policy. G-IKEv2 specifies one method by which LKH can be used for
forward and backward access control. Other methods of using LKH, as
well as other group management algorithms such as OFT or Subset
Difference may be added to G-IKEv2 as part of a later document. Any
such addition MUST be due to a Standards Action as defined in
[RFC2434].
3.3.3. Forward Access Control Requirements
When group membership is altered using a group management algorithm
new GSA TEKs (and their associated keys) are usually also needed.
New GSAs and keys ensure that members who were denied access can no
longer participate in the group.
If forward access control is a desired property of the group, new GSA
TEKs and the associated key packets in the KD payload MUST NOT be
included in a G-IKEv2 rekey message which changes group membership.
This is required because the GSA TEK policy and the associated key
packets in the KD payload are not protected with the new KEK. A
second G-IKEv2 rekey message can deliver the new GSA TEKS and their
associated keys because it will be protected with the new KEK, and
thus will not be visible to the members who were denied access.
If forward access control policy for the group includes keeping group
policy changes from members that are denied access to the group, then
two sequential G-IKEv2 rekey messages changing the group KEK MUST be
sent by the GCKS. The first G-IKEv2 rekey message creates a new KEK
for the group. Group members, which are denied access, will not be
able to access the new KEK, but will see the group policy since the
G-IKEv2 rekey message is protected under the current KEK. A
subsequent G-IKEv2 rekey message containing the changed group policy
and again changing the KEK allows complete forward access control. A
G-IKEv2 rekey message MUST NOT change the policy without creating a
new KEK.
If other methods of using LKH or other group management algorithms
are added to G-IKEv2, those methods MAY remove the above restrictions
requiring multiple G-IKEv2 rekey messages, providing those methods
specify how forward access control policy is maintained within a
single G-IKEv2 rekey message.
3.3.4. Deletion of SAs
There are occasions the GCKS may want to signal to receivers to
delete policy at the end of a broadcast, or if group policy has
changed. Deletion of keys MAY be accomplished by sending the G-IKEv2
Delete Payload [RFC5996], section 3.11 as part of the G-IKEv2
GSA_AUTH or GSA_REKEY Exchange.
Rowles, et al. Expires April 17, 2015 [Page 13]
Internet-Draft G-IKEv2 October 2014
When a policy delete is required the GCKS sends a rekey of the
following format:
Members (Responder) GCKS (Initiator)
-------------------- ------------------
<-- HDR, SK {
[GSA], [KD], [D,] AUTH }
The GSA MAY specify the remaining active time of the remaining policy
by using the DTD attribute in the GSA GAP. If a GCKS has no further
SAs to send to group members, the GSA and KD payloads MUST be omitted
from the message. There may be circumstances where the GCKS may want
to start over with a clean slate. If the administrator is no longer
confident in the integrity of the group, the GCKS can signal deletion
of all policy of a particular TEK protocol by sending a TEK with a
SPI value equal to zero in the delete payload. For example, if the
GCKS wishes to remove all the KEKs and all the TEKs in the group, the
GCKS SHOULD send a delete payload with a spi of zero and a
protocol_id of a TEK protocol_id value define in Section 4.5,
followed by another delete payload with a spi of zero and protocol_id
of zero, indicating that the KEK SA should be deleted.
3.3.5. GSA_REKEY GCKS Operations
The GCKS may initiate a rekey message if group membership and/or
policy has changed, or if the keys are about to expire. The GCKS
builds the rekey message with value of the message id that is one
greater than the previous rekey. If the message is using a new KEK
attribute, the message id is reset to 1 in this message. The GSA and
KD follow with the same characteristics as in the GSA Registration
exchange. The AUTH payload is created by hashing the string
"G-IKEv2" and the message created so far, and then digitally signed.
Finally, the payloads following the HDR are encrypted using the
current KEK encryption key.
3.3.6. GSA_REKEY GM Operations
The group member receives the Rekey Message from the GCKS, decrypts
the message using the current KEK, validates the signature using the
public key retrieved in a previous G-IKEv2 exchange, verifies the
message id, and processes the GSA and KD payloads. The group member
then downloads the new data security SA and/or new Rekey GSA. The
parsing of the payloads is identical to the registration exchange.
Anti-replay protection is achieved when the group member rejects
GSA_REKEY message which has message id smaller than the current
message id that the GM is expecting. The GM expects the message id
in the first GSA_REKEY message it receives to be equal or greater
Rowles, et al. Expires April 17, 2015 [Page 14]
Internet-Draft G-IKEv2 October 2014
than the message id it receives in the KEK_MESSAGE_ID attribute. The
GM expects the message id in the subsequence GSA_REKEY message to be
greater than the last valid GSA_REKEY message it received.
If the SA payload includes Data-Security SA including a counter-modes
of operation and the receiving group member is a sender for that SA,
the group member uses its current SID value with the Data-Security
SAs to create counter-mode nonces. If it is a sender and does not
hold a current SID value, it MUST NOT install the Data-Security SAs.
It MAY initiate a GSA_REGISTRATION exchange to the GCKS in order to
obtain an SID value (along with current group policy).
4. Header and Payload Formats
Refer to IKEv2 [RFC5996] for existing payloads.
4.1. The G-IKEv2 Header
G-IKEv2 uses the same IKE header format as specified in RFC 5996
section 3.1.
Several new payload formats are required in the group security
exchanges.
Next Payload Type Value
----------------- -----
Group Identification (IDg) 50
Group Security Association (GSA) 51
Key Download (KD) 52
New exchange types GSA_AUTH, GSA_REGISTRATION and GSA_REKEY are added
to the IKEv2 [RFC5996] protocol.
Exchange Type Value
-------------- -----
GSA_AUTH 39
GSA_REGISTRATION 40
GSA_REKEY 41
Major Version is 2 and Minor Version is 0 as in IKEv2 [RFC5996]. IKE
SA initiator SPI, IKE SA responder SPI, Flags, Message Id are as
specified in [RFC5996].
4.2. Group Identification (IDg) Payload
The IDg Payload allows the group member to indicate which group it
wants to join. The payload is constructed by using the IKEv2
[RFC5996] Identification Payload. ID type ID_KEY_ID MUST be
Rowles, et al. Expires April 17, 2015 [Page 15]
Internet-Draft G-IKEv2 October 2014
supported. ID types ID_IPV4_ADDR, ID_FQDN, ID_RFC822_ADDR,
ID_IPV6_ADDR SHOULD be supported. ID types ID_DER_ASN1_DN and
ID_DER_ASN1_GN are not expected to be used.
4.3. Group Security Association Payload
The Group Security Association payload is used by the GCKS to assert
security attributes for both Re-key and Data-security SAs.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Next Payload ! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Security Association Payload fields are defined as follows:
o Next Payload (1 octet) -- Identifies the next payload type for the
G-IKEv2 registration or the G-IKEv2 rekey message.
o RESERVED (1 octet) -- Must be zero.
o Payload Length (2 octets) -- Is the octet length of the current
payload including the generic header and all TEK and KEK policies.
4.3.1. GSA policy
Following GSA generic payload header are GSA policies for group
rekeying (KEK) and/or data traffic SAs (TEK). There may be zero or
one GSA KEK policy, zero or more GAP policy, and zero or more GSA TEK
policies, where either one GSA KEK or GSA TEK payload MUST be
present.
This latitude allows various group policies to be accommodated. For
example if the group policy does not require the use of a Re-key SA,
the GCKS would not need to send an GSA KEK attribute to the group
member since all SA updates would be performed using the Registration
SA. Alternatively, group policy might use a Re-key SA but choose to
download a KEK to the group member only as part of the Registration
SA. Therefore, the GSA KEK policy would not be necessary as part of
the GSA_REKEY message.
Specifying multiple GSA TEKs allows multiple sessions to be part of
the same group and multiple streams to be associated with a session
(e.g., video, audio, and text) but each with individual security
association policy.
Rowles, et al. Expires April 17, 2015 [Page 16]
Internet-Draft G-IKEv2 October 2014
A GAP payload allows for the distribution of group-wise policy, such
as instructions as to when to activate and de-activate SAs.
Policies following the GSA payload has common header
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Type ! RESERVED ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
Type is defined as follow:
0 - RESERVED
1 - KEK
2 - GAP
3 - TEK
4-240 - RESERVED
241-255 - private and experimental
4.4. KEK Policy
The GSA KEK (GSAK) policy contains security attributes for the KEK
method for a group and parameters specific to the G-IKEv2
registration operation. The source and destination identities
describe the identities used for the G-IKEv2 registration datagram.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Type ! RESERVED ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! !
~ SPI ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! !
~ <Source Traffic Selector> ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! !
~ <Destination Traffic Selector> ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
~ KEK Attributes ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
Rowles, et al. Expires April 17, 2015 [Page 17]
Internet-Draft G-IKEv2 October 2014
The GSAK Payload fields are defined as follows:
o Type (1 octet) -- Identifies the GSA payload type KEK present in
the G-IKEv2 registration or the G-IKEv2 rekey message.
o RESERVED (1 octet) -- Must be zero.
o Length (2 octets) -- Length of this structure including KEK
attributes.
o SPI (16 octets) -- Security Parameter Index for the KEK. The SPI
must be the IKEv2 Header SPI pair where the first 8 octets become
the "Initiator's SPI" field of the G-IKEv2 rekey message IKEv2
HDR, and the second 8 octets become the "Responder's SPI" in the
same HDR. As described above, these SPIs are assigned by the
GCKS.
o Source & Destination Traffic Selectors - Substructures describing
the source and destination of the identities. These identities
refer to the source and destination of the next KEK rekey SA.
Defined format and values are specified by IKEv2 [RFC5996],
section 3.13.1.
o KEK Attributes -- Contains KEK policy attributes associated with
the group. The following sections describe the possible
attributes. Any or all attributes may be optional, depending on
the group policy.
4.4.1. KEK Attributes
The following attributes may be present in a GSA KEK policy. The
attributes must follow the format defined in IKEv2 [RFC5996] section
3.3.5. In the table, attributes that are defined as TV are marked as
Basic (B); attributes that are defined as TLV are marked as Variable
(V).
ID Class Value Type
-------- ----- ----
RESERVED 0
KEK_MANAGEMENT_ALGORITHM 1 B
KEK_ENCR_ALGORITHM 2 B
KEK_KEY_LENGTH 3 B
KEK_KEY_LIFETIME 4 V
KEK_INTEGRITY_ALGORITHM 5 B
KEK_AUTH_METHOD 6 B
KEK_AUTH_ALGORITHM 7 B
KEK_MESSAGE_ID 8 B
Rowles, et al. Expires April 17, 2015 [Page 18]
Internet-Draft G-IKEv2 October 2014
The following attributes may only be included in a G-IKEv2
registration message: KEK_MANAGEMENT_ALGORITHM.
Minimum attributes that must be sent as part of an GSA KEK:
KEK_ENCR_ALGORITHM, KEK_KEY_LENGTH (if the cipher definition includes
a variable length key), KEK_MESSAGE_ID, KEK_KEY_LIFETIME,
KEK_INTEGRITY_ALGORITHM, KEK_AUTH_METHOD and KEK_AUTH_ALGORITHM
(except for DSA based algorithms).
4.4.2. KEK_MANAGEMENT_ALGORITHM
The KEK_MANAGEMENT_ALGORITHM class specifies the group KEK management
algorithm used to provide forward or backward access control (i.e.,
used to exclude group members). Defined values are specified in the
following table.
KEK Management Type Value
------------------- -----
RESERVED 0
LKH 1
Expert Review 2-127
Private Use 128-255
4.4.3. KEK_ENCR_ALGORITHM
The KEK_ENCR_ALGORITHM class specifies the encryption algorithm using
with the KEK. This is the same as IKEv2 encryption algorithm defined
in [RFC5996] section 3.3.2. If a KEK_MANAGEMENT_ALGORITHM is defined
which defines multiple keys (e.g., LKH), and if the management
algorithm does not specify the algorithm for those keys, then the
algorithm defined by the KEK_ENCR_ALGORITHM attribute MUST be used
for all keys which are included as part of the management.
4.4.4. KEK_KEY_LENGTH
The KEK_KEY_LENGTH class specifies the KEK Algorithm key length (in
bits).
The Group Controller/Key Server (GCKS) adds the KEK_KEY_LENGTH
attribute to the GSA payload when distributing KEK policy to group
members. The group member verifies whether or not it has the
capability of using a cipher key of that size. If the cipher
definition includes a fixed key length, the group member can make its
decision solely using KEK_ENCR_ALGORITHM attribute and does not need
the KEK_KEY_LENGTH attribute. Sending the KEK_KEY_LENGTH attribute
in the GSA payload is OPTIONAL if the KEK cipher has a fixed key
length.
Rowles, et al. Expires April 17, 2015 [Page 19]
Internet-Draft G-IKEv2 October 2014
4.4.5. KEK_KEY_LIFETIME
The KEK_KEY_LIFETIME class specifies the maximum time for which the
KEK is valid. The GCKS may refresh the KEK at any time before the
end of the valid period. The value is a four (4) octet number
defining a valid time period in seconds.
4.4.6. KEK_INTEGRITY_ALGORITHM
KEK_INTEGRITY specifies the integrity algorithm. This integrity
algorithm is specified in IKEv2 RFC 5996 section 3.3.2.
4.4.7. KEK_AUTH_METHOD
KEK_AUTH_METHOD specifies the method of authentication used. This is
the same as IKEv2 Auth Method specified in IKEv2 RFC 5996 section 3.8
4.4.8. KEK_AUTH_ALGORITHM
KEK_AUTH_ALGORITHM specifies the hash algorithm uses to generate AUTH
key to authenticate GSA_REKEY message. Hash algorithms are defined
in IANA registry IKEv2 Hash Algorithms [IKEV2-IANA]. This attribute
can be used by group member to determine in advance if it support the
algorithm used in the rekey message.
4.4.9. KEK_MESSAGE_ID
KEK_MESSAGE_ID define the start message id to be used by the GCKS in
the GSA_REKEY message. Message ID is 4 octets unsigned integer.
4.5. GSA TEK Policy
The GSA TEK (GSAT) policy contains security attributes for a single
TEK associated with a group.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Type ! RESERVED ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Protocol-ID ! TEK Protocol-Specific Payload !
+-+-+-+-+-+-+-+-+ ~
~ !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
The GSAT Payload fields are defined as follows:
Rowles, et al. Expires April 17, 2015 [Page 20]
Internet-Draft G-IKEv2 October 2014
o Type (1 octet) -- Identifies the GSA payload type TEK present in
the G-IKEv2 registration or the G-IKEv2 rekey message.
o RESERVED (1 octet) -- Must be zero.
o Length (2 octets) -- Length of this structure, including the TEK
Protocol-Specific Payload.
o Protocol-ID (1 octet) -- Value specifying the Security Protocol.
The following table defines values for the Security Protocol
Protocol ID Value
----------- -----
RESERVED 0
GSA_PROTO_IPSEC_ESP 1
GSA_PROTO_IPSEC_AH 2
Expert Review 3-127
Private Use 128-255
Support for the GSA_PROTO_IPSEC_AH GSA TEK is OPTIONAL.
o TEK Protocol-Specific Payload (variable) -- Payload which
describes the attributes specific for the Protocol-ID.
4.5.1. TEK ESP and AH Protocol-Specific Policy
The TEK Protocol-Specific policy contains of two traffic selectors
for source and destination of the protecting traffic, SPI, Transform,
and Attributes.
The TEK Protocol-Specific policy for ESP is as follows:
Rowles, et al. Expires April 17, 2015 [Page 21]
Internet-Draft G-IKEv2 October 2014
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! SPI !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
| |
~ <Source Traffic Selector> ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ <Destination Traffic Selector> |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
| |
~ <Transform> ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! TEK Attributes ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
The GSAT Policy fields are defined as follows:
o SPI (4 octets) -- Security Parameter Index.
o Source & Destination Traffic Selectors - The traffic selectors
describe the source and the destination of the protecting traffic.
The format and values are defined in IKEv2 [RFC5996], section
3.13.1.
o Transform -- A substructure specifies the transform information.
The format and values are defined in IKEv2 [RFC5996], section
3.3.2.
o TEK Attributes -- Contains TEK policy attributes associated with
the group. The following sections describe the possible
attributes. Any or all attributes may be optional, depending on
the group policy. [RFC5996], section 3.3.5.
Attribute Types
Rowles, et al. Expires April 17, 2015 [Page 22]
Internet-Draft G-IKEv2 October 2014
class value type
--------------------------------------
Life Duration 1 V
Specifies the time-to-live for the overall security
association. When the TEK expires, all keys downloaded
under the association (AH or ESP) must be re-rekeyed.
The life duration attribute defines the actual length
of the component lifetime in seconds that can be
protected.
If unspecified, the default value shall be assumed to be
28800 seconds (8 hours).
Mode 2 B
In the absence of this attribute tunnel mode will be used.
Value of 1 is used for transport mode.
4.6. GSA Group Associated Policy
Group specific policy that does not belong to rekey policy (GSA KEK)
or traffic encryption policy (GSA TEK) can be distributed to all
group member using GSA GAP (Group Associated Policy).
The GSA GAP payload is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Type ! RESERVED ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Group Associated Policy Attributes ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
The GSA GAP payload fields are defined as follows:
o Type (1 octet) -- Identifies the GSA payload type GAP present in
the G-IKEv2 registration or the G-IKEv2 rekey message.
o RESERVED (1 octet) -- Must be zero.
o Length (2 octets) -- Length of this structure, including the GSA
GAP header and Attributes.
Rowles, et al. Expires April 17, 2015 [Page 23]
Internet-Draft G-IKEv2 October 2014
o Group Associated Policy Attributes (variable) -- Contains
attributes following the format defined in Section 3.3.5 of
[RFC5996].
Attribute Types:
Attribute Type Value Type
-------------- ----- ----
RESERVED 0
ACTIVATION_TIME_DELAY 1 B
DEACTIVATION_TIME_DELAY 2 B
Unassigned 3-127
Private Use 128-255
Unassigned 256-32767
Several group associated policy attributes are defined below. A
G-IKEv2 implementation MUST abort if it encounters an attribute or
capability that it does not understand.
4.6.1. ACTIVATION_TIME_DELAY/DEACTIVATION_TIME_DELAY
Section 4.2.1 of RFC 5374 specifies a key rollover method that
requires two values be given it from the group key management
protocol. The ACTIVATION_TIME_DELAY attribute allows a GCKS to set
the Activation Time Delay (ATD) for SAs generated from TEKs. The ATD
defines how long after receiving new SAs that they are to be
activated by the GM. The ATD value is in seconds.
The DEACTIVATION_TIME_DELAY allows the GCKS to set the Deactivation
Time Delay (DTD) for previously distributed SAs. The DTD defines how
long after receiving new SAs that it should deactivate SAs that are
destroyed by the re-key event. The value is in seconds.
The values of ATD and DTD are independent. However, the DTD value
should be larger, which allows new SAs to be activated before older
SAs are deactivated. Such a policy ensures that protected group
traffic will always flow without interruption.
4.7. Key Download Payload
The Key Download Payload contains group keys for the group specified
in the GSA Payload. These key download payloads can have several
security attributes applied to them based upon the security policy of
the group as defined by the associated GSA Payload.
Rowles, et al. Expires April 17, 2015 [Page 24]
Internet-Draft G-IKEv2 October 2014
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Next Payload ! RESERVED ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! Number of Key Packets ! RESERVED2 !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
~ Key Packets ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
The Key Download Payload fields are defined as follows:
o Next Payload (1 octet) -- Identifier for the payload type of the
next payload in the message. If the current payload is the last
in the message, then this field will be zero.
o RESERVED (1 octet) -- Unused, set to zero.
o Payload Length (2 octets) -- Length in octets of the current
payload, including the generic payload header.
o Number of Key Packets (2 octets) -- Contains the total number of
both TEK and Rekey arrays being passed in this data block.
o Key Packets Several types of key packets are defined. Each Key
Packet has the following format.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! KD Type ! RESERVED ! KD Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
! SPI Size ! SPI (variable) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
~ Key Packet Attributes ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-!
o Key Download (KD) Type (1 octet) -- Identifier for the Key Data
field of this Key Packet.
Rowles, et al. Expires April 17, 2015 [Page 25]
Internet-Draft G-IKEv2 October 2014
Key Download Type Value
----------------- -----
RESERVED 0
TEK 1
KEK 2
LKH 3
SID 4
Expert Review 5-127
Private Use 128-255
"KEK" is a single key whereas LKH is an array of key-encrypting keys.
o RESERVED (1 octet) -- Unused, set to zero.
o Key Download Length (2 octets) -- Length in octets of the Key
Packet data, including the Key Packet header.
o SPI Size (1 octet) -- Value specifying the length in octets of the
SPI as defined by the Protocol-Id.
o SPI (variable length) -- Security Parameter Index which matches a
SPI previously sent in an GSAK or GSAT Payload.
o Key Packet Attributes (variable length) -- Contains Key
information. The format of this field is specific to the value of
the KD Type field. The following sections describe the format of
each KD Type.
4.7.1. TEK Download Type
The following attributes may be present in a TEK Download Type.
Exactly one attribute matching each type sent in the GSAT payload
MUST be present. The attributes must follow the format defined in
IKEv2 (Section 3.3.5 of [RFC5996]). In the table, attributes defined
as TV are marked as Basic (B); attributes defined as TLV are marked
as Variable (V).
TEK Class Value Type
--------- ----- ----
RESERVED 0
TEK_ALGORITHM_KEY 1 V
TEK_INTEGRITY_KEY 2 V
If no TEK key packets are included in a Registration KD payload, the
group member can expect to receive the TEK as part of a Re-key SA.
At least one TEK must be included in each Re-key KD payload.
Multiple TEKs may be included if multiple streams associated with the
SA are to be rekeyed.
Rowles, et al. Expires April 17, 2015 [Page 26]
Internet-Draft G-IKEv2 October 2014
4.7.1.1. TEK_ALGORITHM_KEY
The TEK_ALGORITHM_KEY class contains encryption keying material for
this SPI. This keying material will be used with the encryption
algorithm specified in the GSAT payload, and according to the IPsec
transform describing that encryption algorithm. The keying material
is treated equivalent to IKEv2 KEYMAT derived for that IPsec
transform. If the encryption algorithm requires a nonce (e.g., AES-
GCM), the nonce is chose as shown in Section 3.2.
4.7.1.2. TEK_INTEGRITY_KEY
The TEK_INTEGRITY_KEY class declares that the integrity key for this
SPI is contained as the Key Packet Attribute. The integrity
algorithm that will use this key was specified in the GSAT payload.
TEK integrity key type AUTH_HMAC_SHA1_96 keys will consist of 160
bits [RFC2404], and AUTH_HMAC_MD5_96 keys will consist of 128 bits
[RFC2403]. AUTH_HMAC-SHA2_256_128 and AUTH_AES_128_GMAC keys will
have a key length equal to the output length of the hash functions
[RFC4868] [RFC4543]. Readers should refer to IKEV2IANA for the
latest values.
4.7.2. KEK Download Type
The following attributes may be present in a KEK Download Type.
Exactly one attribute matching each type sent in the GSAK payload
MUST be present. The attributes must follow the format defined in
IKEv2 (Section 3.3.5 of [RFC5996]). In the table, attributes defined
as TV are marked as Basic (B); attributes defined as TLV are marked
as Variable (V).
KEK Class Value Type
--------- ----- ----
RESERVED 0
KEK_ENCR_KEY 1 V
KEK_INTEGRITY_KEY 2 V
KEK_AUTH_KEY
If the KEK key packet is included, there MUST be only one present in
the KD payload.
4.7.2.1. KEK_ENCR_KEY
The KEK_ENCR_KEY class declares the encryption key for this SPI is
contained in the Key Packet Attribute. The encryption algorithm that
will use this key was specified in the GSAK payload.
Rowles, et al. Expires April 17, 2015 [Page 27]
Internet-Draft G-IKEv2 October 2014
If the mode of operation for the algorithm requires an Initialization
Vector (IV), an explicit IV MUST be included in the KEK_ALGORITHM_KEY
before the actual key.
4.7.2.2. KEK_INTEGRITY_KEY
The KEK_INTEGRITY_KEY class declares the integrity key for this SPI
is contained in the Key Packet Attribute. The integrity algorithm
that will use this key was specified in the GSAK payload.
4.7.2.3. KEK_AUTH_KEY
The KEK_AUTH_KEY class declares that the public key for this SPI is
contained in the Key Packet Attribute, which may be useful when no
public key infrastructure is available. The signature algorithm that
will use this key was specified in the GSAK payload. RSA public key
format is defined in RFC 3447, Section A.1.1. DSS public key format
is defined in RFC 3270 Section 2.3.2. For ECDSA Public keys, use
format described in RFC 5480 Section 2.2.
4.7.3. LKH Download Type
The LKH key packet is comprised of attributes representing different
leaves in the LKH key tree.
The following attributes are used to pass an LKH KEK array in the KD
payload. The attributes must follow the format defined in IKEv2
(Section 3.3.5 of [RFC5996]). In the table, attributes defined as TV
are marked as Basic (B); attributes defined as TLV are marked as
Variable (V).
KEK Class Value Type
--------- ----- ----
RESERVED 0
LKH_DOWNLOAD_ARRAY 1 V
LKH_UPDATE_ARRAY 2 V
AUTH_ALGORITHM_KEY 3 V
Expert Review 4-127
Private Use 128-255
If an LKH key packet is included in the KD payload, there must be
only one present.
4.7.3.1. LKH_DOWNLOAD_ARRAY
This attribute is used to download a set of keys to a group member.
It MUST NOT be included in a IKEv2 rekey message KD payload if the
IKEv2 rekey is sent to more than the group member. If an
Rowles, et al. Expires April 17, 2015 [Page 28]
Internet-Draft G-IKEv2 October 2014
LKH_DOWNLOAD_ARRAY attribute is included in a KD payload, there must
be only one present.
This attribute consists of a header block, followed by one or more
LKH keys.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! LKH Version ! # of LKH Keys ! RESERVED !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! LKH Keys !
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The KEK_LKH attribute fields are defined as follows:
o LKH version (1 octet) -- Contains the version of the LKH protocol
which the data is formatted in. Must be one.
o Number of LKH Keys (2 octets) -- This value is the number of
distinct LKH keys in this sequence.
o RESERVED (1 octet) -- Unused, set to zero.
Each LKH Key is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! LKH ID ! Key Type ! RESERVED !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Key Creation Date !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Key expiration Date !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Key Handle !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! !
~ Key Data ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o LKH ID (2 octets) -- This is the position of this key in the
binary tree structure used by LKH.
o Key Type (1 octet) -- This is the encryption algorithm for which
this key data is to be used. This value is specified in
Section 4.4.3.
Rowles, et al. Expires April 17, 2015 [Page 29]
Internet-Draft G-IKEv2 October 2014
o RESERVED (1 octet) -- Unused, set to zero.
o Key Creation Date (4 octets) -- This is the time value of when
this key data was originally generated. A time value of zero
indicates that there is no time before which this key is not
valid.
o Key Expiration Date (4 octets) -- This is the time value of when
this key is no longer valid for use. A time value of zero
indicates that this key does not have an expiration time.
o Key Handle (4 octets) -- This is the randomly generated value to
uniquely identify a key within an LKH ID.
o Key Data (variable length) -- This is the actual encryption key
data, which is dependent on the Key Type algorithm for its format.
If the mode of operation for the algorithm requires an
Initialization Vector (IV), an explicit IV MUST be included in the
Key Data field before the actual key.
The Key Creation Date and Key expiration Dates MAY be zero. This is
necessary in the case where time synchronization within the group is
not possible.
The first LKH Key structure in an LKH_DOWNLOAD_ARRAY attribute
contains the Leaf identifier and key for the group member. The rest
of the LKH Key structures contain keys along the path of the key tree
in order from the leaf, culminating in the group KEK.
4.7.3.2. LKH_UPDATE_ARRAY
This attribute is used to update the keys for a group. It is most
likely to be included in a G-IKEv2 rekey message KD payload to rekey
the entire group. This attribute consists of a header block,
followed by one or more LKH keys, as defined in Section 4.7.3.1.
There may be any number of UPDATE_ARRAY attributes included in a KD
payload.
Rowles, et al. Expires April 17, 2015 [Page 30]
Internet-Draft G-IKEv2 October 2014
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! LKH Version ! # of LKH Keys ! RESERVED !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! LKH ID ! RESERVED2 !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Key Handle !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! LKH Keys !
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o LKH version (1 octet) -- Contains the version of the LKH protocol
which the data is formatted in. Must be one.
o Number of LKH Keys (2 octets) -- This value is the number of
distinct LKH keys in this sequence.
o RESERVED (1 octet) -- Unused, set to zero.
o LKH ID (2 octets) -- This is the node identifier associated with
the key used to encrypt the first LKH Key.
o RESERVED2 (2 octets) -- Unused, set to zero.
o Key Handle (4 octets) -- This is the value to uniquely identify
the key within the LKH ID which was used to encrypt the first LKH
key.
The LKH Keys are as defined in Section 4.7.3.1. The LKH Key
structures contain keys along the path of the key tree in order from
the LKH ID found in the LKH_UPDATE_ARRAY header, culminating in the
group KEK. The Key Data field of each LKH Key is encrypted with the
LKH key preceding it in the LKH_UPDATE_ARRAY attribute. The first
LKH Key is encrypted under the key defined by the LKH ID and Key
Handle found in the LKH_UPDATE_ARRAY header.
4.7.4. SID Download Type
This attribute is used to download one or use more Sender-ID (SID)
values for the exclusive use of a group member.
Rowles, et al. Expires April 17, 2015 [Page 31]
Internet-Draft G-IKEv2 October 2014
KEK Class Value Type
--------- ----- ----
RESERVED 0
NUMBER_OF_SID_BITS 1 V
SID_VALUE 2 V
Expert Review 3-128
Private Use 129-255
Unassigned 256-32767
Because a SID value is intended for a single group member, the SID
Download type MUST NOT be distributed in a GROUPKEY_PUSH message
distributed to multiple group members.
4.7.4.1. NUMBER_OF_SID_BITS
The NUMBER_OF_SID_BITS class declares how many bits of the cipher
nonce in which to represent an SID value. This value applied to each
SID value is distributed in the SID Download.
4.7.4.2. SID_VALUE
The SID_VALUE class declares a single SID value for the exclusive use
of the a group member. Multiple SID_VALUE attributes MAY be included
in a SID Download.
4.7.4.3. GM Semantics
The SID_VALUE attribute value distributed to the group member MUST be
used by that group member as the SID field portion of the IV for all
Data-Security SAs including a counter-based mode of operation
distributed by the GCKS as a part of this group. When the Sender-
Specific IV (SSIV) field for any Data-Security SA is exhausted, the
group member MUST no longer act as a sender on that SA using its
active SID. The group member SHOULD re-register, at which time the
GCKS will issue a new SID to the group member, along with either the
same Data-Security SAs or replacement ones. The new SID replaces the
existing SID used by this group member, and also resets the SSIV
value to its starting value. A group member MAY re-register prior to
the actual exhaustion of the SSIV field to avoid dropping data
packets due to the exhaustion of available SSIV values combined with
a particular SID value.
A group member MUST NOT process an SID Download Type KD payload
present in a GSA-REKEY message.
Rowles, et al. Expires April 17, 2015 [Page 32]
Internet-Draft G-IKEv2 October 2014
4.7.4.4. GCKS Semantics
If any KD payload includes keying material that is associated with a
counter-mode of operation, an SID Download Type KD payload containing
at least one SID_VALUE attribute MUST be included. The GCKS MUST NOT
send the SID Download Type KD payload as part of a GSA-REKEY message,
because distributing the same sender-specific policy to more than one
group member will reduce the security of the group.
4.8. Delete Payload
There are occasions the GCKS may want to signal to receivers to
delete policy at the end of a broadcast, or if policy has changed.
Deletion of keys MAY be accomplished by sending an IKEv2 Delete
Payload, section 3.11 of [RFC5996] as part of the GSA_AUTH or
GSA_REKEY Exchange. One or more Delete payloads MAY be placed
following the HDR payload in the GSA_AUTH or GSA_REKEY Exchange.
The Protocol ID MUST be TBD1 for GSA_REKEY Exchange, 2 for AH or 3
for ESP. Note that only one protocol id value can be defined in a
Delete payload. If a TEK and a KEK SA for GSA_REKEY Exchange must be
deleted, they must be sent in different Delete payloads. Similarly,
if a TEK specifying ESP and a TEK specifying AH need to be deleted,
they must be sent in different Delete payloads.
There may be circumstances where the GCKS may want to start over with
a clean slate. If the administrator is no longer confident in the
integrity of the group, the GCKS can signal deletion of all policy of
a particular TEK protocol by sending a TEK with an SPI value equal to
zero in the delete payload. For example, if the GCKS wishes to
remove all the KEKs and all the TEKs in the group, the GCKS SHOULD
send a delete payload with an SPI of zero and a Protocol-ID of AH or
ESP Protocol-ID value, followed by another delete payload with an SPI
value of zero and Protocol-ID of KEK SA, indicating that the KEK SA
should be deleted.
4.9. Notify Payload
G-IKEv2 uses the same notify payload as specified in [RFC5996],
section 3.10.
There are additional notify message types introduced by G-IKEv2 to
communicate error conditions and status.
Rowles, et al. Expires April 17, 2015 [Page 33]
Internet-Draft G-IKEv2 October 2014
NOTIFY MESSAGES - ERROR TYPES Value
-------------------------------------------------------------------
INVALID_GROUP_ID - 45
Indicates the group id sent during registration process is invalid.
AUTHORIZATION_FAILED - 46
Sent in the response to GSA_AUTH message when authorization failed.
NOTIFY MESSAGES - STATUS TYPES Value
-------------------------------------------------------------------
SENDER_REQUEST_ID - 16429
Sent in GSA_AUTH or GSA_REGISTRATION to request SIDs from GCKS.
The data includes a count of how many SID values it desires.
4.10. Authentication Payload
G-IKEv2 uses the same Authentication payload as specified in
[RFC5996], section 3.8, to sign the rekey message.
5. Security Considerations
5.1. GSA registration and secure channel
G-IKEv2 registration exchange uses IKEv2 IKE_SA_INIT, GSA_AUTH and
GSA_REGISTRATION inheriting all the security considerations
documented in [RFC5996] section 5 Security Considerations, including
authentication, confidentiality, protection against man-in-the
middle, protection against replay/reflection attacks, and denial of
service protection. In addition, G-IKEv2 brings in the capability to
authorize a particular group member regardless of whether they have
the IKEv2 credentials.
5.2. GSA maintenance channel
The GSA maintenance channel is cryptographically and integrity
protected using the cryptographic algorithm and key negotiated in the
GSA member registration exchanged.
5.2.1. Authentication/Authorization
Authentication is implicit, the public key of the identity is
distributed during the registration, and the receiver of the rekey
message uses that public key and identity to verify the message is
come from the authorized GCKS.
Rowles, et al. Expires April 17, 2015 [Page 34]
Internet-Draft G-IKEv2 October 2014
5.2.2. Confidentiality
Confidentiality is provided by distributing a confidentiality key as
part of the GSA member registration exchange.
5.2.3. Man-in-the-Middle Attack Protection
GSA maintenance channel is integrity protected by using digital
signature.
5.2.4. Replay/Reflection Attack Protection
The GSA rekey message includes a monotonically increasing sequence
number to protect against replay and reflection attacks. A group
member will recognize a replayed message by comparing the message id
number to that of the last received rekey message, any rekey message
contains message id number less than or equal to the last received
value SHOULD be discarded. Implementations SHOULD keep a record of
recently received GSA rekey messages for this comparison.
6. IANA Considerations
6.1. New registries
A new set of registries are created for this draft.
GSA type Registry, see Section 4.3.1
KEK Attributes Registry, see Section 4.4.1
KEK Management Algorithm Registry, see Section 4.4.2
GSA TEK Payload Protocol ID Type Registry, see Section 4.5
TEK Attributes Registry, see Section 4.5
Key Download Type Registry, see Section 4.7
TEK Download Type Registry, see Section 4.7.1
KEK Download Type Registry, see Section 4.7.2
LKH Download Type Registry, see Section 4.7.3
SID Download Type Registry, see Section 4.7.4
Rowles, et al. Expires April 17, 2015 [Page 35]
Internet-Draft G-IKEv2 October 2014
6.2. New payload and exchange types to existing IKEv2 registry
The following new payloads and exchange types already allocated by
IANA
The present document describes new IKEv2 Next Payload types, see
Section 4.1
The present document describes new IKEv2 Exchanges types, see
Section 4.1
The present document describes new IKEv2 Notify Payload types, see
Section 4.9
New payload type request to be allocated by IANA
The present document describes a new IKEv2 Security Protocol
Identifiers protocol ID, see Section 4.8. TBD1 represents new IKEv2
Security Protocol Identifiers for GIKEv2_REKEY.
6.3. New Name spaces
The present document describes many new name spaces for use in the
G-IKEv2 payloads. Those may be found in subsections under Section 4.
A new G-IKEv2 registry has been created for these name spaces.
Portions of name spaces marked "RESERVED" are reserved for IANA
allocation. New values MUST be added due to a Standards Action as
defined in [RFC2434].
Portions of name spaces marked "Private Use" may be allocated by
implementations for their own purposes.
7. Acknowledgements
The authors thank Lakshminath Dondeti and Jing Xiang for originating
the GKDP document and providing the basis behind the protocol.
8. References
8.1. Normative References
[RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen,
"Internet Key Exchange Protocol Version 2 (IKEv2)", RFC
5996, September 2010.
Rowles, et al. Expires April 17, 2015 [Page 36]
Internet-Draft G-IKEv2 October 2014
[RFC6054] McGrew, D. and B. Weis, "Using Counter Modes with
Encapsulating Security Payload (ESP) and Authentication
Header (AH) to Protect Group Traffic", RFC 6054, November
2010.
8.2. Informative References
[IKE-HASH]
Kivinen, T., "Fixing IKE Phase 1 & 2 Authentication
HASHs", November 2001, <http://tools.ietf.org/html/
draft-ietf-ipsec-ike-hash-revised-03>.
[IKEV2-IANA]
IANA, "Internet Key Exchange Version 2 (IKEv2) Parameters
- Transform Type 3 - Integrity Algorithm Transfrom IDs",
December 2013, <http://www.iana.org/assignments/ikev2-
parameters/ikev2-parameters.xhtml#ikev2-parameters-7>.
[NNL] Naor, D., Noal, M., and J. Lotspiech, "Revocation and
Tracing Schemes for Stateless Receivers", Advances in
Cryptology, Crypto '01, Springer-Verlag LNCS 2139, 2001,
pp. 41-62, 2001,
<http://www.wisdom.weizmann.ac.il/~naor/>.
[OFT] McGrew, D. and A. Sherman, "Key Establishment in Large
Dynamic Groups Using One-Way Function Trees", Manuscript,
submitted to IEEE Transactions on Software Engineering,
1998, <http://download.nai.com/products/media/nai/misc/
oft052098.ps>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2407] Piper, D., "The Internet IP Security Domain of
Interpretation for ISAKMP", RFC 2407, November 1998.
[RFC2408] Maughan, D., Schneider, M., and M. Schertler, "Internet
Security Association and Key Management Protocol
(ISAKMP)", RFC 2408, November 1998.
[RFC2409] Harkins, D. and D. Carrel, "The Internet Key Exchange
(IKE)", RFC 2409, November 1998.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.
Rowles, et al. Expires April 17, 2015 [Page 37]
Internet-Draft G-IKEv2 October 2014
[RFC2627] Wallner, D., Harder, E., and R. Agee, "Key Management for
Multicast: Issues and Architectures", RFC 2627, June 1999.
[RFC3686] Housley, R., "Using Advanced Encryption Standard (AES)
Counter Mode With IPsec Encapsulating Security Payload
(ESP)", RFC 3686, January 2004.
[RFC4106] Viega, J. and D. McGrew, "The Use of Galois/Counter Mode
(GCM) in IPsec Encapsulating Security Payload (ESP)", RFC
4106, June 2005.
[RFC4309] Housley, R., "Using Advanced Encryption Standard (AES) CCM
Mode with IPsec Encapsulating Security Payload (ESP)", RFC
4309, December 2005.
[RFC4543] McGrew, D. and J. Viega, "The Use of Galois Message
Authentication Code (GMAC) in IPsec ESP and AH", RFC 4543,
May 2006.
[RFC6407] Weis, B., Rowles, S., and T. Hardjono, "The Group Domain
of Interpretation", RFC 6407, October 2011.
Appendix A. Differences between G-IKEv2 and RFC 6407
KE Payload - The KE payload is no longer needed with the availability
of newer algorithms such as AES and GCM which provide adequate
protection therefore not needing the PFS capability the KE payload
offers.
SIG Payload - The AUTH payload is used for the same purpose instead.
DOI/Situation - The DOI and Situation fields in the SA payload are no
longer needed in the G-IKEv2 protocol as port 848 will distinguish
the IKEv2 messages from the G-IKEv2 messages.
SEQ Payload - The SEQ payload is no longer needed since IKEv2 header
has message id which is used to prevent message replay attacks.
Authors' Addresses
Sheela Rowles
Cisco Systems
170 W. Tasman Drive
San Jose, California 95134-1706
USA
Phone: +1-408-527-7677
Email: sheela@cisco.com
Rowles, et al. Expires April 17, 2015 [Page 38]
Internet-Draft G-IKEv2 October 2014
Aldous Yeung (editor)
Cisco Systems
170 W. Tasman Drive
San Jose, California 95134-1706
USA
Phone: +1-408-853-2032
Email: cyyeung@cisco.com
Paulina Tran
Cisco Systems
170 W. Tasman Drive
San Jose, California 95134-1706
USA
Phone: +1-408-526-8902
Email: ptran@cisco.com
Yoav Nir
Check Point Software Technologies Ltd.
5 Hasolelim St.
Tel Aviv 67897
Israel
Email: ynir@checkpoint.com
Rowles, et al. Expires April 17, 2015 [Page 39]