draft-ietf-rohc-ikev2-extensions-hcoipsec-09.txt   draft-ietf-rohc-ikev2-extensions-hcoipsec-10.txt 
Network Working Group E. Ertekin Network Working Group E. Ertekin
Internet-Draft C. Christou Internet-Draft C. Christou
Expires: February 13, 2010 R. Jasani Expires: June 7, 2010 R. Jasani
Booz Allen Hamilton Booz Allen Hamilton
T. Kivinen T. Kivinen
Safenet, Inc. Safenet, Inc.
C. Bormann C. Bormann
Universitaet Bremen TZI Universitaet Bremen TZI
August 12, 2009 December 4, 2009
IKEv2 Extensions to Support Robust Header Compression over IPsec IKEv2 Extensions to Support Robust Header Compression over IPsec
(ROHCoIPsec) (ROHCoIPsec)
draft-ietf-rohc-ikev2-extensions-hcoipsec-09 draft-ietf-rohc-ikev2-extensions-hcoipsec-10
Abstract
In order to integrate Robust Header Compression (ROHC) with IPsec, a
mechanism is needed to signal ROHC channel parameters between end-
points. Internet Key Exchange (IKE) is a mechanism which can be
leveraged to exchange these parameters. This document specifies
extensions to IKEv2 that will allow ROHC and its associated channel
parameters to be signaled for IPsec security associations (SAs).
Status of this Memo Status of this Memo
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Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Abstract include Simplified BSD License text as described in Section 4.e of
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described in the BSD License.
In order to integrate ROHC with IPsec [ROHCOIPSEC], a mechanism is This document may contain material from IETF Documents or IETF
needed to signal ROHC channel parameters between end-points. Contributions published or made publicly available before November
Internet Key Exchange (IKE) is a mechanism which can be leveraged to 10, 2008. The person(s) controlling the copyright in some of this
exchange these parameters. This document specifies extensions to material may not have granted the IETF Trust the right to allow
IKEv2 [IKEV2] that will allow ROHC and its associated channel modifications of such material outside the IETF Standards Process.
parameters to be signaled for IPsec security associations (SAs). Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. ROHC Channel Initialization for ROHCoIPsec . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. ROHC Channel Parameters that are Signaled . . . . . . . . 4 3. ROHC Channel Initialization for ROHCoIPsec . . . . . . . . . . 3
2.1.1. ROHC_SUPPORTED Notify Message . . . . . . . . . . . . 5 3.1. ROHC_SUPPORTED Notify Message . . . . . . . . . . . . . . 3
2.1.2. ROHC Attribute Types . . . . . . . . . . . . . . . . . 6 3.1.1. ROHC Attributes . . . . . . . . . . . . . . . . . . . 5
2.2. ROHC Channel Parameters that are Implicitly Set . . . . . 9 3.1.2. ROHC Attribute Types . . . . . . . . . . . . . . . . . 6
3. Security Considerations . . . . . . . . . . . . . . . . . . . 9 3.2. ROHC Channel Parameters that are Implicitly Set . . . . . 8
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 4. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10
6.1. Normative References . . . . . . . . . . . . . . . . . . . 10 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.2. Informative References . . . . . . . . . . . . . . . . . . 11 7.1. Normative References . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 7.2. Informative References . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction 1. Introduction
Increased packet header overhead due to IPsec [IPSEC] can result in Increased packet header overhead due to IPsec [IPSEC] can result in
the inefficient utilization of bandwidth. Coupling ROHC [ROHC] with the inefficient utilization of bandwidth. Coupling ROHC [ROHC] with
IPsec offers an efficient way to transfer protected IP traffic. IPsec offers an efficient way to transfer protected IP traffic.
ROHCoIPsec [ROHCOIPSEC] requires configuration parameters to be ROHCoIPsec [ROHCOIPSEC] requires configuration parameters to be
initialized at the compressor and decompressor. Current initialized at the compressor and decompressor. Current
specifications for hop-by-hop ROHC negotiate these parameters through specifications for hop-by-hop ROHC negotiate these parameters through
a link-layer protocol such as Point-to-Point Protocol (PPP) (i.e. a link-layer protocol such as Point-to-Point Protocol (PPP) (i.e.
ROHC over PPP [ROHC-PPP]). Since key exchange protocols (e.g. ROHC over PPP [ROHC-PPP]). Since key exchange protocols (e.g. IKEv2
IKEv2) can be used to dynamically establish parameters between IPsec [IKEV2]) can be used to dynamically establish parameters between
peers, this document defines extensions to IKEv2 to signal ROHC IPsec peers, this document defines extensions to IKEv2 to signal ROHC
parameters for ROHCoIPsec. parameters for ROHCoIPsec.
2. ROHC Channel Initialization for ROHCoIPsec 2. Terminology
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 [BRA97].
3. ROHC Channel Initialization for ROHCoIPsec
The following subsections define extensions to IKEv2 which enables an The following subsections define extensions to IKEv2 which enables an
initiator and a responder to signal parameters required to establish initiator and a responder to signal parameters required to establish
a ROHC channel for a ROHCoIPsec session. a ROHC channel for a ROHCoIPsec session.
2.1. ROHC Channel Parameters that are Signaled 3.1. ROHC_SUPPORTED Notify Message
ROHC channel parameters will be signaled at either the establishment ROHC channel parameters MUST be signaled at either the establishment
or rekeying of a Child SA. Specifically, a new Notify message type or rekeying of a Child SA. Specifically, a new Notify message type
is used during the IKE_AUTH and CREATE_CHILD_SA exchanges to convey is used during the IKE_AUTH and CREATE_CHILD_SA exchanges to convey
these parameters. these parameters.
The Notify payload sent by the initiator contains the channel The Notify payload sent by the initiator MUST contain the channel
parameters for the ROHC implementation. Specifically, these parameters for the ROHC session. These parameters indicate the
parameters indicate the capabilities of the ROHC decompressor at the capabilities of the ROHC decompressor at the initiator. Upon receipt
initiator. Upon receipt of the initiator's request, the responder of the initiator's request, the responder will either ignore the
will either ignore the payload (if it doesn't support ROHC or the payload (if it doesn't support ROHC or the proposed parameters) or
proposed parameters) or respond with a Notify payload that contains respond with a Notify payload that contains its own ROHC channel
its own ROHC channel parameters. parameters.
Note that only one Notify payload is used to convey ROHC parameters. Note that only one Notify payload is used to convey ROHC parameters.
If multiple Notify payloads containing ROHC parameters are received, If multiple Notify payloads containing ROHC parameters are received,
all but the first such Notify payload must be dropped. If the all but the first such Notify payload MUST be dropped. If the
initiator does not receive a Notify Payload with the responder's ROHC initiator does not receive a Notify Payload with the responder's ROHC
channel parameters, ROHC must not be enabled on the Child SA. channel parameters, ROHC MUST NOT be enabled on the Child SA.
A new Notify Message Type value, denoted ROHC_SUPPORTED, indicates A new Notify Message Type value, denoted ROHC_SUPPORTED, indicates
that the Notify payload is conveying ROHC channel parameters. The that the Notify payload is conveying ROHC channel parameters (Section
value for the ROHC_SUPPORTED message is specified in Section 4. 4).
The Notify Payload (defined in [IKEV2]) is illustrated in Figure 1. The Notify Payload (defined in RFC 4306 [IKEV2]) is illustrated in
Figure 1.
1 2 3 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length ! ! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Protocol ID ! SPI Size ! Notify Message Type ! ! Protocol ID ! SPI Size ! Notify Message Type !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! ! ! !
~ Security Parameter Index (SPI) ~ ~ Security Parameter Index (SPI) ~
skipping to change at page 5, line 27 skipping to change at page 5, line 35
~ Notification Data ~ ~ Notification Data ~
! ! ! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1. Notify Payload format. Figure 1. Notify Payload format.
The fields of the Notify Payload are set as follows: The fields of the Notify Payload are set as follows:
Next Payload (1 octet) Next Payload (1 octet)
Identifier for the payload type of the next payload in the Identifier for the payload type of the next payload in the
message. Further details can be found in [IKEV2]. message. Further details can be found in RFC 4306 [IKEV2].
Critical (1 bit) Critical (1 bit)
Since all IKEv2 implementations must support the Notify Payload, Since all IKEv2 implementations support the Notify Payload, this
this value is zero. value MUST be set to zero.
Payload Length (2 octets) Payload Length (2 octets)
As defined in [IKEV2], this field indicates the length of the As defined in RFC 4306 [IKEV2], this field indicates the length of
current payload, including the generic payload header. the current payload, including the generic payload header.
Protocol ID (1 octet) Protocol ID (1 octet)
Since this Notification message is used during the creation of a Since this Notification message is used during the creation of a
Child SA, this field must be set to zero. Child SA, this field MUST be set to zero.
SPI Size (1 octet) SPI Size (1 octet)
This value must be set to zero, since no SPI is applicable (ROHC This value MUST be set to zero, since no SPI is applicable (ROHC
parameters are set at SA creation, thus the SPI has not been parameters are set at SA creation, thus the SPI has not been
defined). defined).
Notify Message Type (2 octets) Notify Message Type (2 octets)
This field must be set to ROHC_SUPPORTED. This field MUST be set to ROHC_SUPPORTED.
2.1.1. ROHC_SUPPORTED Notify Message Security Parameter Index (SPI)
Since the SPI Size field is 0, this field MUST NOT be transmitted.
Notification Data (variable)
This field MUST contain at least three ROHC Attributes (Section
3.1.1).
3.1.1. ROHC Attributes
The ROHC_SUPPORTED Notify message is used to signal channel The ROHC_SUPPORTED Notify message is used to signal channel
parameters between ROHCoIPsec compressor and decompressor. The parameters between ROHCoIPsec compressor and decompressor. The
message contains a list of "ROHC Attributes" which contain the message contains a list of "ROHC Attributes" which contain the
parameters required for the ROHCoIPsec session. parameters required for the ROHCoIPsec session.
The format for signaling ROHC Attributes takes a similar format to The format for signaling ROHC Attributes takes a similar format to
the Transform Attributes described in Section 3.3.5 of [IKEV2]. The the Transform Attributes described in Section 3.3.5 of RFC
ROHC Attribute is shown in Figure 2. 4306[IKEV2]. The ROHC Attribute is shown in Figure 2.
1 2 3 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
!A! ROHC Attribute Type ! AF=0 ROHC Attribute Length ! !A! ROHC Attribute Type ! AF=0 ROHC Attribute Length !
!F! ! AF=1 ROHC Attribute Value ! !F! ! AF=1 ROHC Attribute Value !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! AF=0 ROHC Attribute Value ! ! AF=0 ROHC Attribute Value !
! AF=1 Not Transmitted ! ! AF=1 Not Transmitted !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2. Format of the ROHC Attribute. Figure 2. Format of the ROHC Attribute.
o ROHC Attribute Type (2 octets) - Unique identifier for each type o Attribute Format (AF) (1 bit) - If the AF bit is a zero (0), then
of ROHC attribute (see Section 2.1.2). The most significant bit the ROHC Attribute is expressed in a Type/Length/Value format. If
in the field is the Attribute Format (AF) bit. If the AF bit is a the AF bit is a one (1), then the ROHC attribute is expressed in a
zero (0), then the ROHC Attribute is expressed in a Type/Length/ Type/Value (TV) format.
Value (TLV) format. If the AF bit is a one (1), then the ROHC o ROHC Attribute Type (15 bits) - Unique identifier for each type of
Attribute is expressed in a Type/Value (TV) format. ROHC attribute (Section 3.1.2).
o ROHC Attribute Length (2 octets) - Length (in octets) of the o ROHC Attribute Length (2 octets) - Length (in octets) of the
Attribute Value. When the AF bit is a one (1), the ROHC Attribute Attribute Value. When the AF bit is a one (1), the ROHC Attribute
Value is 2 octets and the ROHC Attribute Length field is not Value is 2 octets and the ROHC Attribute Length field is not
present. present.
o ROHC Attribute Value (variable length) - Value of the ROHC o ROHC Attribute Value (variable length) - Value of the ROHC
Attribute associated with the ROHC Attribute Type. If the AF bit Attribute associated with the ROHC Attribute Type. If the AF bit
is a zero (0), this field's length is defined by the ROHC is a zero (0), this field's length is defined by the ROHC
Attribute Length field. If the AF bit is a one (1), the length of Attribute Length field. If the AF bit is a one (1), the length of
the ROHC Attribute Value is 2 octets. the ROHC Attribute Value is 2 octets.
2.1.2. ROHC Attribute Types 3.1.2. ROHC Attribute Types
This section describes five ROHC Attribute Types: MAX_CID, This section describes five ROHC Attribute Types: MAX_CID,
ROHC_PROFILE, ROHC_INTEG, ROHC_ICV_LEN, and MRRU. The value ROHC_PROFILE, ROHC_INTEG, ROHC_ICV_LEN, and MRRU. The value
allocated for each ROHC Attribute Type is specified in Section 4. allocated for each ROHC Attribute Type is specified in Section 4.
Maximum Context Identifier (MAX_CID, AF = 1) MAX_CID (Maximum Context Identifier, AF = 1)
The MAX_CID attribute is a mandatory attribute. Exactly one The MAX_CID attribute is a mandatory attribute. Exactly one
MAX_CID attribute must be sent. The MAX_CID field indicates the MAX_CID attribute MUST be sent. The MAX_CID field indicates the
maximum value of a context Identifier supported by the ROHCoIPsec maximum value of a context Identifier supported by the ROHCoIPsec
decompressor. This attribute value is two octets in length. The decompressor. This attribute value is two octets in length. The
range of values for MAX_CID must be at least 0 and at most 16383 range of values for MAX_CID MUST be at least 0 and at most 16383
(the value 0 implies having one context). The recipient of the (the value 0 implies having one context). The recipient of the
MAX_CID Attribute must only use up to MAX_CID context identifiers MAX_CID Attribute MUST only use up to MAX_CID context identifiers
for compression. for compression.
ROHC Profile (ROHC_PROFILE, AF = 1) Note that the MAX_CID parameter is a one-way notification (i.e.,
the sender of the attribute indicates what it can handle to the
other end); therefore, different values for MAX_CID may be
announced in each direction.
ROHC_PROFILE (ROHC Profile, AF = 1)
The ROHC_PROFILE attribute is a mandatory attribute. Each The ROHC_PROFILE attribute is a mandatory attribute. Each
ROHC_PROFILE attribute has a fixed length of 4 octets, and its ROHC_PROFILE attribute has a fixed length of 4 octets, and its
attribute value is a two-octet long profile identifier. There may attribute value is a two-octet long ROHC Profile Identifier
be one or more ROHC_PROFILE attribute(s) included in the [ROHCPROF]. There MUST be at least one ROHC_PROFILE attribute
ROHC_SUPPORTED Notify Message. If multiple ROHC_PROFILE included in the ROHC_SUPPORTED Notify Message. If multiple
attributes are sent, the order is arbitrary. The recipient of a ROHC_PROFILE attributes are sent, the order is arbitrary. The
ROHC_PROFILE attribute(s) must only use the profile(s) proposed recipient of a ROHC_PROFILE attribute(s) MUST only use the
for compression. profile(s) proposed for compression.
Several common profiles are defined in [ROHCV1] and [ROHCV2]. Several common profiles are defined in RFC 3095 [ROHCV1] and 5225
Note, however, that two versions of the same profile must not be [ROHCV2]. Note, however, that two versions of the same profile
signaled. For example, if a ROHCoIPsec decompressor supports both MUST NOT be signaled. For example, if a ROHCoIPsec decompressor
ROHCv1 UDP (0x0002) and ROHCv2 UDP (0x0102), both profiles must supports both ROHCv1 UDP (0x0002) and ROHCv2 UDP (0x0102), both
not be signaled. This restriction is needed, as packets profiles MUST NOT be signaled. This restriction is needed, as
compressed by ROHC express only the 8 least significant bits of packets compressed by ROHC express only the 8 least significant
the profile identifier; since the 8 least significant bits for bits of the profile identifier; since the 8 least significant bits
corresponding profiles in ROHCv1 and ROHCv2 are identical, the for corresponding profiles in ROHCv1 and ROHCv2 are identical, the
decompressor is not capable of determining the ROHC version that decompressor is not capable of determining the ROHC version that
was used to compress the packet. was used to compress the packet.
Integrity Algorithm for Verification of Decompressed Headers Note that the ROHC_PROFILE attribute is a one-way notification;
(ROHC_INTEG, AF = 1) therefore, different values for ROHC_PROFILE may be announced in
The ROHC_INTEG attribute is a mandatory attribute. There must be each direction.
at least one ROHC_INTEG attribute contained within the
ROHC_SUPPORTED Notify message. The attribute contains an
integrity algorithm that is used to ensure the integrity of the
decompressed packets (i.e. ensure that the packet headers are
properly decompressed).
Authentication algorithms that must be supported are specified in ROHC_INTEG (Integrity Algorithm for Verification of Decompressed
Section 3.2 of [CRYPTO-ALG]. More explicitly, the implementation Headers, AF = 1)
conformance requirements for authentication algorithms are as The ROHC_INTEG attribute is a mandatory attribute. There MUST be
follows: at least one ROHC_INTEG attribute contained within the
ROHC_SUPPORTED Notify message. The attribute value contains the
identifier of an integrity algorithm that is used to ensure the
integrity of the decompressed packets (i.e. ensure that the
decompressed packet headers are identical to the original packet
headers prior to compression).
Requirement Algorithm Authentication algorithms that MUST be supported are specified in
----------- ---------------- the "Authentication Algorithms" table in section 3.1.1 ("ESP
Must AUTH_HMAC_SHA1_96 Encryption and Authentication Algorithms") of RFC 4835 [CRYPTO-
Should+ AUTH_AES_XCBC_MAC_96 ALG] (or its successor).
May AUTH_HMAC_MD5_96
The integrity algorithm is represented by a two octet value that The integrity algorithm is represented by a two octet value that
corresponds to the value listed in [IKEV2-PARA] "For Transform corresponds to the value listed in the IKEv2 Parameters registry
Type 3 (Integrity Algorithm)" section. Upon receipt of the [IKEV2-PARA] "For Transform Type 3 (Integrity Algorithm)" section.
ROHC_INTEG attribute(s), the responder must select exactly one of Upon receipt of the ROHC_INTEG attribute(s), the responder MUST
proposed algorithms and send the selected algorithm back to the select exactly one of the proposed algorithms; the chosen value is
initiator. The selected integrity algorithm must be used in both sent back in the ROHC_SUPPORTED Notify message returned by the
directions. responder to the initiator. The selected integrity algorithm MUST
be used in both directions. If the responder does not accept any
of the algorithms proposed by the initiator, ROHC MUST NOT be
enabled on the SA.
It is noted that: It is noted that:
1. The key for this Integrity Algorithm is computed using the 1. The keys (one for each direction) for this Integrity Algorithm
same method as is used to compute IPsec's Integrity Algorithm are derived from the IKEv2 KEYMAT (see [IKEV2], Section 2.17).
key ([IKEV2], Section 2.17). When a ROHC-enabled CHILD_SA is For the purposes of this key derivation, ROHC is considered to
be an IPsec protocol. When a ROHC-enabled CHILD_SA is
rekeyed, the key associated with this integrity algorithm is rekeyed, the key associated with this integrity algorithm is
rekeyed as well. rekeyed as well.
2. A ROHCoIPsec initiator may signal a value of zero (0x0000) in 2. A ROHCoIPsec initiator MAY signal a value of zero (0x0000) in
a ROHC_INTEG attribute. This corresponds to "NONE" in the a ROHC_INTEG attribute. This corresponds to "NONE" in the
Integrity Algorithm Transform ID registry. The ROHCoIPsec Integrity Algorithm Transform ID registry. The ROHCoIPsec
responder may select this value by responding to the initiator responder MAY select this value by responding to the initiator
with a ROHC_INTEG attribute of zero (0x0000). In this with a ROHC_INTEG attribute of zero (0x0000). In this
scenario, no integrity algorithm is applied in either scenario, no integrity algorithm is applied in either
direction. direction.
3. The ROHC_INTEG attribute is a parameter that is negotiated
between two ends. In other words, the initiator indicates
what it supports; the responder selects one of the ROHC_INTEG
values proposed, and sends the selected value to the
initiator.
Integrity Algorithm Length (ROHC_ICV_LEN, AF = 1) ROHC_ICV_LEN (Integrity Algorithm Length, AF = 1)
The ROHC_ICV_LEN attribute is an optional attribute. There may be The ROHC_ICV_LEN attribute is an optional attribute. There MAY be
zero or one ROHC_ICV_LEN attribute contained within the zero or one ROHC_ICV_LEN attribute contained within the
ROHC_SUPPORTED Notify message. The attribute specifies the number ROHC_SUPPORTED Notify message. The attribute specifies the number
of ICV octets the sender expects to receive on incoming ROHC of Integrity Check Value (ICV) octets the sender expects to
packets. The ICV of the negotiated ROHC_INTEG algorithms are receive on incoming ROHC packets. The ICV of the negotiated
truncated to ROHC_ICV_LEN bytes by taking the first ROHC_ICV_LEN ROHC_INTEG algorithms MUST be truncated to ROHC_ICV_LEN bytes by
bytes of the output. Both the initiator and responder announce taking the first ROHC_ICV_LEN bytes of the output. Both the
their preference for their own ICV length. The recipient of the initiator and responder announce a single value for their own ICV
ROHC_ICV_LEN attribute must truncate the ICV to the length length. The recipient of the ROHC_ICV_LEN attribute MUST truncate
contained in the message. If ROHC_ICV_LEN length is zero, then no the ICV to the length contained in the message. If the value of
ICV is calculated or sent. If no ROHC_ICV_LEN attribute is sent the ROHC_ICV_LEN attribute is zero, then an ICV MUST NOT be sent.
at all or the ROHC_ICV_LEN is larger than the length of the ICV of If no ROHC_ICV_LEN attribute is sent at all or the ROHC_ICV_LEN is
selected algorithm, then the full ICV length as specified by the larger than the length of the ICV of selected algorithm, then the
ROHC_INTEG algorithm is sent. full ICV length as specified by the ROHC_INTEG algorithm MUST be
sent.
Maximum reconstructed reception unit (MRRU, AF = 1) Note that the ROHC_ICV_LEN attribute is a one-way notification;
The MRRU attribute is an optional attribute. There may be zero or therefore, different values for ROHC_ICV_LEN may be announced in
each direction.
MRRU (Maximum Reconstructed Reception Unit, AF = 1)
The MRRU attribute is an optional attribute. There MAY be zero or
one MRRU attribute contained within the ROHC_SUPPORTED Notify one MRRU attribute contained within the ROHC_SUPPORTED Notify
message. If present, the attribute value is two octets in length. message. The attribute value is two octets in length. The
The attribute specifies the size of the largest reconstructed unit attribute specifies the size of the largest reconstructed unit in
in octets that the ROHCoIPsec decompressor is expected to octets that the ROHCoIPsec decompressor is expected to reassemble
reassemble from ROHC segments. This size includes the CRC, and from ROHC segments (see Section 5.2.5 of [ROHCV1]). This size
the ROHC ICV. If MRRU is 0 or if no MRRU attribute is sent, no includes the CRC, and the ROHC ICV. If MRRU is 0 or if no MRRU
segment headers are allowed on the ROHCoIPsec channel. attribute is sent, segment headers MUST NOT be transmitted on the
ROHCoIPsec channel.
If an unknown ROHC Attribute Type Value is received, it is silently Note that the MRRU attribute is a one-way notification; therefore,
ignored. different values for MRRU may be announced in each direction.
2.2. ROHC Channel Parameters that are Implicitly Set If an unknown ROHC Attribute Type Value is received, it MUST be
silently ignored.
The following ROHC channel parameters are not signaled: 3.2. ROHC Channel Parameters that are Implicitly Set
The following ROHC channel parameters MUST NOT be signaled:
o LARGE_CIDS: This value is implicitly determined by the value of o LARGE_CIDS: This value is implicitly determined by the value of
MAX_CID (e.g. if MAX_CID is <= 15, LARGE_CIDS is assumed to be 0). MAX_CID (e.g. if MAX_CID is <= 15, LARGE_CIDS is assumed to be 0).
o FEEDBACK_FOR: When a pair of SAs are created (one in each o FEEDBACK_FOR: When a pair of SAs are created (one in each
direction), the ROHC channel parameter FEEDBACK_FOR is set direction), the ROHC channel parameter FEEDBACK_FOR MUST be set
implicitly to the other SA of the pair (i.e. the SA pointing in implicitly to the other SA of the pair (i.e. the SA pointing in
the reverse direction). the reverse direction).
3. Security Considerations 4. Security Considerations
The ROHC channel parameters signaled via IKEv2 do not add any new The ability to negotiate the length of the ROHC ICV may introduce
vulnerabilities beyond those associated with the normal operation of vulnerabilities to the ROHCoIPsec protocol. Specifically, the
IKEv2. capability to signal a short ICV length may result in scenarios where
erroneous packets are forwarded into the protected domain. This
security consideration is documented in further detail in Section
6.1.4 of [ROHCOIPSEC] and Section 5 of [IPSEC-ROHC].
4. IANA Considerations This security consideration can be mitigated by using longer ICVs,
but this comes at the cost of additional overhead, which reduces the
overall benefits offered by ROHCoIPsec.
5. IANA Considerations
This document defines a new Notify Message (Status Type). Therefore, This document defines a new Notify Message (Status Type). Therefore,
IANA is requested to allocate one value from the IKEv2 Notify Message IANA is requested to allocate one value from the IKEv2 Notify Message
registry to indicate ROHC_SUPPORTED. Note that, since this Notify registry to indicate ROHC_SUPPORTED. Note that, since this Notify
Message is a Status Type, values ranging from 0 to 16383 must not be Message is a Status Type, values ranging from 0 to 16383 must not be
allocated for ROHC_SUPPORTED. allocated for ROHC_SUPPORTED.
In addition, IANA is requested to allocate a "ROHC Attribute Types" In addition, IANA is requested to create a new "ROHC Attribute Types"
registry in the IKEv2 Parameters Registry [IKEV2-PARA]. Within the registry in the IKEv2 Parameters Registry [IKEV2-PARA]. Within the
"ROHC Attribute Types" registry, this document allocates the "ROHC Attribute Types" registry, this document allocates the
following values: following values:
Registry Registry:
Value ROHC Attribute Type Reference Value ROHC Attribute Type Format Reference
------------------------------------------------------------------ ----------- -------------------------------------- ------ ---------
0 RESERVED [rfcThis] 0 RESERVED [rfcThis]
1 Maximum Context Identifier (MAX_CID) [rfcThis] 1 Maximum Context Identifier (MAX_CID) TV [rfcThis]
2 ROHC Profile (ROHC_PROFILE) [rfcThis] 2 ROHC Profile (ROHC_PROFILE) TV [rfcThis]
3 ROHC Integrity Algorithm (ROHC_INTEG) [rfcThis] 3 ROHC Integrity Algorithm (ROHC_INTEG) TV [rfcThis]
4 ROHC ICV Length in bytes (ROHC_ICV_LEN) [rfcThis] 4 ROHC ICV Length in bytes (ROHC_ICV_LEN) TV [rfcThis]
5 Maximum Reconstructed Reception Unit (MRRU) [rfcThis] 5 Maximum Reconstructed Reception Unit (MRRU) TV [rfcThis]
6-65536 Unassigned 6-16383 Unassigned [rfcThis]
16384-32767 Private use [rfcThis]
Following the policies outlined in [IANA-CONSIDERATIONS], the IANA Following the policies outlined in [IANA-CONSIDERATIONS], the IANA
policy for assigning new values for the ROHC Attribute Types registry policy for assigning new values for the ROHC Attribute Types registry
shall be Specification Required: values and their meanings must be shall be Designated Expert.
documented in a permanent and readily available public specification,
in sufficient detail so that interoperability between independent
implementations is possible.
5. Acknowledgments For registration requests, the responsible IESG area director will
appoint the Designated Expert during the IETF last call. The
intention is that any allocation will be accompanied by a published
RFC. The Designated expert will post a request to both the rohc and
ipsec mailing lists (or a successor designated by the Area Director)
for comment and review. Before expiration of the IETF last call, the
Designated Expert will either approve or deny the registration
request and publish a notice of the decision to both mailing lists
(or their successors), as well as informing IANA. A denial notice
must be justified by an explanation.
6. Acknowledgments
The authors would like to thank Mr. Sean O'Keeffe, Mr. James Kohler, The authors would like to thank Mr. Sean O'Keeffe, Mr. James Kohler,
and Ms. Linda Noone of the Department of Defense, as well as Mr. Rich and Ms. Linda Noone of the Department of Defense, as well as Mr. Rich
Espy of OPnet for their contributions and support in the development Espy of OPnet for their contributions and support in the development
of this document. of this document.
The authors would also like to thank Mr. Yoav Nir, and Mr. Robert A The authors would also like to thank Mr. Yoav Nir, and Mr. Robert A
Stangarone Jr.: both served as committed document reviewers for this Stangarone Jr.: both served as committed document reviewers for this
specification. specification.
skipping to change at page 10, line 34 skipping to change at page 11, line 35
o Dr. Stephen Kent o Dr. Stephen Kent
o Mr. Lars-Erik Jonsson o Mr. Lars-Erik Jonsson
o Mr. Pasi Eronen o Mr. Pasi Eronen
o Dr. Jonah Pezeshki o Dr. Jonah Pezeshki
o Mr. Carl Knutsson o Mr. Carl Knutsson
o Dr. Joseph Touch o Dr. Joseph Touch
Finally, the authors would also like to thank Mr. Tom Conkle, Ms. Finally, the authors would also like to thank Mr. Tom Conkle, Ms.
Michele Casey, and Mr. Etzel Brower. Michele Casey, and Mr. Etzel Brower.
6. References 7. References
6.1. Normative References 7.1. Normative References
[IPSEC] Kent, S. and K. Seo, "Security Architecture for the [IPSEC] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005. Internet Protocol", RFC 4301, December 2005.
[ROHC] Jonsson, L-E., Pelletier, G., and K. Sandlund, "The RObust [ROHC] Jonsson, L-E., Pelletier, G., and K. Sandlund, "The RObust
Header Compression (ROHC) Framework", RFC 4995, July 2007. Header Compression (ROHC) Framework", RFC 4995, July 2007.
[IKEV2] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", [IKEV2] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
RFC 4306, December 2005. RFC 4306, December 2005.
[BRA97] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[ROHCV1] Bormann, C., Burmeister, C., Degermark, M., Fukushima, H., [ROHCV1] Bormann, C., Burmeister, C., Degermark, M., Fukushima, H.,
Hannu, H., Jonsson, L., Hakenberg, R., Koren, T., Le, K., Hannu, H., Jonsson, L., Hakenberg, R., Koren, T., Le, K.,
Liu, Z., Martensson, A., Miyazaki, A., Svanbro, K., Liu, Z., Martensson, A., Miyazaki, A., Svanbro, K.,
Wiebke, T., Yoshimura, T., and H. Zheng, "RObust Header Wiebke, T., Yoshimura, T., and H. Zheng, "RObust Header
Compression (ROHC): Framework and four profiles: RTP, UDP, Compression (ROHC): Framework and four profiles: RTP, UDP,
ESP, and uncompressed", RFC 3095, July 2001. ESP, and uncompressed", RFC 3095, July 2001.
[ROHCV2] Pelletier, G. and K. Sandlund, "RObust Header Compression [ROHCV2] Pelletier, G. and K. Sandlund, "RObust Header Compression
Version 2 (ROHCv2): Profiles for RTP, UDP, IP, ESP and UDP Version 2 (ROHCv2): Profiles for RTP, UDP, IP, ESP and UDP
Lite", RFC 5225, April 2008. Lite", RFC 5225, April 2008.
6.2. Informative References [IPSEC-ROHC]
Ertekin, E., Christou, C., and C. Bormann, "IPsec
Extensions to Support ROHCoIPsec", work in progress ,
December 2009.
7.2. Informative References
[ROHCOIPSEC] [ROHCOIPSEC]
Ertekin, E., Jasani, R., Christou, C., and C. Bormann, Ertekin, E., Jasani, R., Christou, C., and C. Bormann,
"Integration of Header Compression over IPsec Security "Integration of Header Compression over IPsec Security
Associations", work in progress , August 2009. Associations", work in progress , December 2009.
[ROHC-PPP] [ROHC-PPP]
Bormann, C., "Robust Header Compression (ROHC) over PPP", Bormann, C., "Robust Header Compression (ROHC) over PPP",
RFC 3241, April 2002. RFC 3241, April 2002.
[ROHCPROF]
"RObust Header Compression (ROHC) Profile Identifiers",
www.iana.org/assignments/rohc-pro-ids , May 2008.
[CRYPTO-ALG] [CRYPTO-ALG]
Manral, V., "Cryptographic Algorithm Implementation Manral, V., "Cryptographic Algorithm Implementation
Requirements for Encapsulating Security Payload (ESP) and Requirements for Encapsulating Security Payload (ESP) and
Authentication Header (AH)", RFC 4835, April 2007. Authentication Header (AH)", RFC 4835, April 2007.
[IKEV2-PARA] [IKEV2-PARA]
IANA, "IKEv2 Parameters, IANA, "IKEv2 Parameters,
http://www.iana.org/assignments/ikev2-parameters", http://www.iana.org/assignments/ikev2-parameters",
January 2008. November 2009.
[IANA-CONSIDERATIONS] [IANA-CONSIDERATIONS]
Narten, T. and H. Alvestrand, "Guidelines for Writing an Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, IANA Considerations Section in RFCs", RFC 5226,
October 1998. October 1998.
Authors' Addresses Authors' Addresses
Emre Ertekin Emre Ertekin
Booz Allen Hamilton Booz Allen Hamilton
13200 Woodland Park Dr. 5220 Pacific Concourse Drive, Suite 200
Herndon, VA 20171 Los Angeles, CA 90045
US US
Email: ertekin_emre@bah.com Email: ertekin_emre@bah.com
Chris Christou Chris Christou
Booz Allen Hamilton Booz Allen Hamilton
13200 Woodland Park Dr. 13200 Woodland Park Dr.
Herndon, VA 20171 Herndon, VA 20171
US US
Email: christou_chris@bah.com Email: christou_chris@bah.com
Rohan Jasani Rohan Jasani
Booz Allen Hamilton Booz Allen Hamilton
skipping to change at page 12, line 26 skipping to change at page 13, line 37
US US
Email: ro@breakcheck.com Email: ro@breakcheck.com
Tero Kivinen Tero Kivinen
Safenet, Inc. Safenet, Inc.
Fredrikinkatu 47 Fredrikinkatu 47
HELSINKI HELSINKI
FI FI
Email: kivinen@safenet-inc.com Email: kivinen@iki.fi
Carsten Bormann Carsten Bormann
Universitaet Bremen TZI Universitaet Bremen TZI
Postfach 330440 Postfach 330440
Bremen D-28334 Bremen D-28334
Germany Germany
Email: cabo@tzi.org Email: cabo@tzi.org
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