< draft-ietf-ipsecme-rfc4307bis-12.txt		draft-ietf-ipsecme-rfc4307bis-13.txt >
	Network Working Group Y. Nir		Network Working Group Y. Nir
	Internet-Draft Check Point		Internet-Draft Check Point
	Obsoletes: 4307 (if approved) T. Kivinen		Obsoletes: 4307 (if approved) T. Kivinen
	Updates: 7296 (if approved) INSIDE Secure		Updates: 7296 (if approved) INSIDE Secure
	Intended status: Standards Track P. Wouters		Intended status: Standards Track P. Wouters
	Expires: March 13, 2017 Red Hat		Expires: March 16, 2017 Red Hat
	D. Migault		D. Migault
	Ericsson		Ericsson
	September 9, 2016		September 12, 2016
	Algorithm Implementation Requirements and Usage Guidance for IKEv2		Algorithm Implementation Requirements and Usage Guidance for IKEv2
	draft-ietf-ipsecme-rfc4307bis-12		draft-ietf-ipsecme-rfc4307bis-13
	Abstract		Abstract
	The IPsec series of protocols makes use of various cryptographic		The IPsec series of protocols makes use of various cryptographic
	algorithms in order to provide security services. The Internet Key		algorithms in order to provide security services. The Internet Key
	Exchange (IKE) protocol is used to negotiate the IPsec Security		Exchange (IKE) protocol is used to negotiate the IPsec Security
	Association (IPsec SA) parameters, such as which algorithms should be		Association (IPsec SA) parameters, such as which algorithms should be
	used. To ensure interoperability between different implementations,		used. To ensure interoperability between different implementations,
	it is necessary to specify a set of algorithm implementation		it is necessary to specify a set of algorithm implementation
	requirements and usage guidance to ensure that there is at least one		requirements and usage guidance to ensure that there is at least one
	algorithm that all implementations support. This document defines		algorithm that all implementations support. This document updates
	the current algorithm implementation requirements and usage guidance		RFC 7296 and obsoletes RFC 4307 in defining the current algorithm
	for IKEv2 and does minor cleaning up of IKEv2 IANA registry. This		implementation requirements and usage guidance for IKEv2, and does
	document does not update the algorithms used for packet encryption		minor cleaning up of the IKEv2 IANA registry. This document does not
	using IPsec Encapsulated Security Payload (ESP).		update the algorithms used for packet encryption using IPsec
			Encapsulated Security Payload (ESP).
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on March 13, 2017.		This Internet-Draft will expire on March 16, 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2016 IETF Trust and the persons identified as the		Copyright (c) 2016 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 4, line 27 ¶		skipping to change at page 4, line 27 ¶
	downgraded from MUST to MUST- or SHOULD, instead of MUST NOT.		downgraded from MUST to MUST- or SHOULD, instead of MUST NOT.
	Similarly, an algorithm that has not been mentioned as mandatory-to-		Similarly, an algorithm that has not been mentioned as mandatory-to-
	implement is expected to be introduced with a SHOULD instead of a		implement is expected to be introduced with a SHOULD instead of a
	MUST.		MUST.
	The current trend toward Internet of Things and its adoption of IKEv2		The current trend toward Internet of Things and its adoption of IKEv2
	requires this specific use case to be taken into account as well.		requires this specific use case to be taken into account as well.
	IoT devices are resource constrained devices and their choice of		IoT devices are resource constrained devices and their choice of
	algorithms are motivated by minimizing the footprint of the code, the		algorithms are motivated by minimizing the footprint of the code, the
	computation effort and the size of the messages to send. This		computation effort and the size of the messages to send. This
	document indicates "[IoT]" when a specified algorithm is specifically		document indicates "(IoT)" when a specified algorithm is specifically
	listed for IoT devices. Requirement levels that are marked as "IoT"		listed for IoT devices. Requirement levels that are marked as "IoT"
	apply to IoT devices and to server-side implementations that might		apply to IoT devices and to server-side implementations that might
	presumably need to interoperate with them, including any general-		presumably need to interoperate with them, including any general-
	purpose VPN gateways.		purpose VPN gateways.
	1.3. Document Audience		1.3. Document Audience
	The recommendations of this document mostly target IKEv2 implementers		The recommendations of this document mostly target IKEv2 implementers
	as implementations need to meet both high security expectations as		as implementations need to meet both high security expectations as
	well as high interoperability between various vendors and with		well as high interoperability between various vendors and with
	skipping to change at page 6, line 8 ¶		skipping to change at page 6, line 8 ¶
	and used for the Encrypted Payload. References to the specification		and used for the Encrypted Payload. References to the specification
	defining these algorithms and the ones in the following subsections		defining these algorithms and the ones in the following subsections
	are in the IANA registry [IKEV2-IANA]. Some of these algorithms are		are in the IANA registry [IKEV2-IANA]. Some of these algorithms are
	Authenticated Encryption with Associated Data (AEAD - [RFC5282]).		Authenticated Encryption with Associated Data (AEAD - [RFC5282]).
	Algorithms that are not AEAD MUST be used in conjunction with an		Algorithms that are not AEAD MUST be used in conjunction with an
	integrity algorithms in Section 3.3.		integrity algorithms in Section 3.3.
	+------------------------+----------+-------+---------+		+------------------------+----------+-------+---------+
	| Name | Status | AEAD? | Comment |		| Name | Status | AEAD? | Comment |
	+------------------------+----------+-------+---------+		+------------------------+----------+-------+---------+
	| ENCR_AES_CBC | MUST | No | [1] |		| ENCR_AES_CBC | MUST | No | (1) |
	| ENCR_CHACHA20_POLY1305 | SHOULD | Yes | |		| ENCR_CHACHA20_POLY1305 | SHOULD | Yes | |
	| ENCR_AES_GCM_16 | SHOULD | Yes | [1] |		| ENCR_AES_GCM_16 | SHOULD | Yes | (1) |
	| ENCR_AES_CCM_8 | SHOULD | Yes | [IoT] |		| ENCR_AES_CCM_8 | SHOULD | Yes | (IoT) |
	| ENCR_3DES | MAY | No | |		| ENCR_3DES | MAY | No | |
	| ENCR_DES | MUST NOT | No | |		| ENCR_DES | MUST NOT | No | |
	+------------------------+----------+-------+---------+		+------------------------+----------+-------+---------+
	[1] - This requirement level is for 128-bit and 256-bit keys.		(1) - This requirement level is for 128-bit and 256-bit keys.
	192-bit keys remain at MAY level. [IoT] - This requirement is for		192-bit keys remain at MAY level. (IoT) - This requirement is for
	interoperability with IoT. Only 128-bit keys are at MUST level.		interoperability with IoT. Only 128-bit keys are at MUST level.
	192-bit and 256-bit keys are at the MAY level.		192-bit and 256-bit keys are at the MAY level.
	ENCR_AES_CBC is raised from SHOULD+ in [RFC4307] to MUST. It is the		ENCR_AES_CBC is raised from SHOULD+ in [RFC4307] to MUST. It is the
	only shared mandatory-to-implement algorithm with RFC4307 and as a		only shared mandatory-to-implement algorithm with RFC4307 and as a
	result it is necessary for interoperability with IKEv2 implementation		result it is necessary for interoperability with IKEv2 implementation
	compatible with RFC4307.		compatible with RFC4307.
	ENCR_CHACHA20_POLY1305 was not ready to be considered at the time of		ENCR_CHACHA20_POLY1305 was not ready to be considered at the time of
	RFC4307. It has been recommended by the CRFG and others as an		RFC4307. It has been recommended by the CRFG and others as an
	skipping to change at page 7, line 33 ¶		skipping to change at page 7, line 33 ¶
	If an algorithm is selected as the integrity algorithm, it SHOULD		If an algorithm is selected as the integrity algorithm, it SHOULD
	also be used as the PRF. When using an AEAD cipher, a choice of PRF		also be used as the PRF. When using an AEAD cipher, a choice of PRF
	needs to be made. The table below lists the recommended algorithms.		needs to be made. The table below lists the recommended algorithms.
	+-------------------+----------+---------+		+-------------------+----------+---------+
	| Name | Status | Comment |		| Name | Status | Comment |
	+-------------------+----------+---------+		+-------------------+----------+---------+
	| PRF_HMAC_SHA2_256 | MUST | |		| PRF_HMAC_SHA2_256 | MUST | |
	| PRF_HMAC_SHA2_512 | SHOULD+ | |		| PRF_HMAC_SHA2_512 | SHOULD+ | |
	| PRF_HMAC_SHA1 | MUST- | |		| PRF_HMAC_SHA1 | MUST- | |
	| PRF_AES128_XCBC | SHOULD | [IoT] |		| PRF_AES128_XCBC | SHOULD | (IoT) |
	| PRF_HMAC_MD5 | MUST NOT | |		| PRF_HMAC_MD5 | MUST NOT | |
	+-------------------+----------+---------+		+-------------------+----------+---------+
	[IoT] - This requirement is for interoperability with IoT		(IoT) - This requirement is for interoperability with IoT
	PRF_HMAC_SHA2_256 was not mentioned in RFC4307, as no SHA2 based		PRF_HMAC_SHA2_256 was not mentioned in RFC4307, as no SHA2 based
	transforms were mentioned. PRF_HMAC_SHA2_256 MUST be implemented in		transforms were mentioned. PRF_HMAC_SHA2_256 MUST be implemented in
	order to replace SHA1 and PRF_HMAC_SHA1.		order to replace SHA1 and PRF_HMAC_SHA1.
	PRF_HMAC_SHA2_512 SHOULD be implemented as a future replacement for		PRF_HMAC_SHA2_512 SHOULD be implemented as a future replacement for
	PRF_HMAC_SHA2_256 or when stronger security is required.		PRF_HMAC_SHA2_256 or when stronger security is required.
	PRF_HMAC_SHA2_512 is preferred over PRF_HMAC_SHA2_384, as the		PRF_HMAC_SHA2_512 is preferred over PRF_HMAC_SHA2_384, as the
	additional overhead of PRF_HMAC_SHA2_512 is negligible.		additional overhead of PRF_HMAC_SHA2_512 is negligible.
	skipping to change at page 8, line 31 ¶		skipping to change at page 8, line 31 ¶
	defining these algorithms are in the IANA registry. When an AEAD		defining these algorithms are in the IANA registry. When an AEAD
	algorithm (see Section 3.1) is proposed, this algorithm transform		algorithm (see Section 3.1) is proposed, this algorithm transform
	type is not in use.		type is not in use.
	+------------------------+----------+---------+		+------------------------+----------+---------+
	| Name | Status | Comment |		| Name | Status | Comment |
	+------------------------+----------+---------+		+------------------------+----------+---------+
	| AUTH_HMAC_SHA2_256_128 | MUST | |		| AUTH_HMAC_SHA2_256_128 | MUST | |
	| AUTH_HMAC_SHA2_512_256 | SHOULD | |		| AUTH_HMAC_SHA2_512_256 | SHOULD | |
	| AUTH_HMAC_SHA1_96 | MUST- | |		| AUTH_HMAC_SHA1_96 | MUST- | |
	| AUTH_AES_XCBC_96 | SHOULD | [IoT] |		| AUTH_AES_XCBC_96 | SHOULD | (IoT) |
	| AUTH_HMAC_MD5_96 | MUST NOT | |		| AUTH_HMAC_MD5_96 | MUST NOT | |
	| AUTH_DES_MAC | MUST NOT | |		| AUTH_DES_MAC | MUST NOT | |
	| AUTH_KPDK_MD5 | MUST NOT | |		| AUTH_KPDK_MD5 | MUST NOT | |
	+------------------------+----------+---------+		+------------------------+----------+---------+
	[IoT] - This requirement is for interoperability with IoT		(IoT) - This requirement is for interoperability with IoT
	AUTH_HMAC_SHA2_256_128 was not mentioned in RFC4307, as no SHA2 based		AUTH_HMAC_SHA2_256_128 was not mentioned in RFC4307, as no SHA2 based
	transforms were mentioned. AUTH_HMAC_SHA2_256_128 MUST be		transforms were mentioned. AUTH_HMAC_SHA2_256_128 MUST be
	implemented in order to replace AUTH_HMAC_SHA1_96.		implemented in order to replace AUTH_HMAC_SHA1_96.
	AUTH_HMAC_SHA2_512_256 SHOULD be implemented as a future replacement		AUTH_HMAC_SHA2_512_256 SHOULD be implemented as a future replacement
	of AUTH_HMAC_SHA2_256_128 or when stronger security is required.		of AUTH_HMAC_SHA2_256_128 or when stronger security is required.
	This value has been preferred over AUTH_HMAC_SHA2_384, as the		This value has been preferred over AUTH_HMAC_SHA2_384, as the
	additional overhead of AUTH_HMAC_SHA2_512 is negligible.		additional overhead of AUTH_HMAC_SHA2_512 is negligible.
	skipping to change at page 9, line 19 ¶		skipping to change at page 9, line 19 ¶
	in RFC4307 so their default status ware MAY. They have been		in RFC4307 so their default status ware MAY. They have been
	downgraded to MUST NOT. There is an industry-wide trend to deprecate		downgraded to MUST NOT. There is an industry-wide trend to deprecate
	DES and MD5. MD5 support is being removed from cryptographic		DES and MD5. MD5 support is being removed from cryptographic
	libraries in general because its non-HMAC use is known to be subject		libraries in general because its non-HMAC use is known to be subject
	to collision attacks, for example as mentioned in [TRANSCRIPTION].		to collision attacks, for example as mentioned in [TRANSCRIPTION].
	3.4. Type 4 - IKEv2 Diffie-Hellman Group Transforms		3.4. Type 4 - IKEv2 Diffie-Hellman Group Transforms
	There are several Modular Exponential (MODP) groups and several		There are several Modular Exponential (MODP) groups and several
	Elliptic Curve groups (ECC) that are defined for use in IKEv2. These		Elliptic Curve groups (ECC) that are defined for use in IKEv2. These
	groups are defined in both the [IKEv2] base document and in		groups are defined in both the [RFC7296] base document and in
	extensions documents and are identified by group number. Note that		extensions documents and are identified by group number. Note that
	it is critical to enforce a secure Diffie-Hellman exchange as this		it is critical to enforce a secure Diffie-Hellman exchange as this
	exchange provides keys for the session. If an attacker can retrieve		exchange provides keys for the session. If an attacker can retrieve
	the private numbers (a, or b) and the public values (g**a, and g**b),		the private numbers (a, or b) and the public values (g**a, and g**b),
	then the attacker can compute the secret and the keys used and		then the attacker can compute the secret and the keys used and
	decrypt the exchange and IPsec SA created inside the IKEv2 SA. Such		decrypt the exchange and IPsec SA created inside the IKEv2 SA. Such
	an attack can be performed off-line on a previously recorded		an attack can be performed off-line on a previously recorded
	communication, years after the communication happened. This differs		communication, years after the communication happened. This differs
	from attacks that need to be executed during the authentication which		from attacks that need to be executed during the authentication which
	must be performed online and in near real-time.		must be performed online and in near real-time.
	skipping to change at page 11, line 8 ¶		skipping to change at page 11, line 8 ¶
	3.5. Summary of Changes from RFC 4307		3.5. Summary of Changes from RFC 4307
	The following table summarizes the changes from RFC 4307.		The following table summarizes the changes from RFC 4307.
	RFC EDITOR: PLEASE REMOVE THIS PARAGRAPH AND REPLACE XXXX IN THE		RFC EDITOR: PLEASE REMOVE THIS PARAGRAPH AND REPLACE XXXX IN THE
	TABLE BELOW WITH THE NUMBER OF THIS RFC		TABLE BELOW WITH THE NUMBER OF THIS RFC
	+---------------------+------------------+------------+		+---------------------+------------------+------------+
	| Algorithm | RFC 4307 | RFC XXXX |		| Algorithm | RFC 4307 | RFC XXXX |
	+---------------------+------------------+------------+		+---------------------+------------------+------------+
	| ENCR_3DES | MUST- | MAY |		| ENCR_3DES | MUST- | MAY |
	| ENCR_NULL | MUST NOT[errata] | (*) |		| ENCR_NULL | MUST NOT[errata] | MUST NOT |
	| ENCR_AES_CBC | SHOULD+ | MUST |		| ENCR_AES_CBC | SHOULD+ | MUST |
	| ENCR_AES_CTR | SHOULD | (*) |		| ENCR_AES_CTR | SHOULD | (*) |
	| PRF_HMAC_MD5 | MAY | MUST NOT |		| PRF_HMAC_MD5 | MAY | MUST NOT |
	| PRF_HMAC_SHA1 | MUST | MUST- |		| PRF_HMAC_SHA1 | MUST | MUST- |
	| PRF_AES128_XCBC | SHOULD+ | SHOULD |		| PRF_AES128_XCBC | SHOULD+ | SHOULD |
	| AUTH_HMAC_MD5_96 | MAY | MUST NOT |		| AUTH_HMAC_MD5_96 | MAY | MUST NOT |
	| AUTH_HMAC_SHA1_96 | MUST | MUST- |		| AUTH_HMAC_SHA1_96 | MUST | MUST- |
	| AUTH_AES_XCBC_96 | SHOULD+ | SHOULD |		| AUTH_AES_XCBC_96 | SHOULD+ | SHOULD |
	| Group 2 (1024-bit) | MUST- | SHOULD NOT |		| Group 2 (1024-bit) | MUST- | SHOULD NOT |
	| Group 14 (2048-bit) | SHOULD+ | MUST |		| Group 14 (2048-bit) | SHOULD+ | MUST |
	+---------------------+------------------+------------+		+---------------------+------------------+------------+
	(*) These algorithms are not mentioned in the above sections, so they		(*) This algorithm is not mentioned in the above sections, so it
	default to MAY.		defaults to MAY.
	4. IKEv2 Authentication		4. IKEv2 Authentication
	IKEv2 authentication may involve a signatures verification.		IKEv2 authentication may involve a signatures verification.
	Signatures may be used to validate a certificate or to check the		Signatures may be used to validate a certificate or to check the
	signature of the AUTH value. Cryptographic recommendations regarding		signature of the AUTH value. Cryptographic recommendations regarding
	certificate validation are out of scope of this document. What is		certificate validation are out of scope of this document. What is
	mandatory to implement is provided by the PKIX Community. This		mandatory to implement is provided by the PKIX Community. This
	document is mostly concerned on signature verification and generation		document is mostly concerned on signature verification and generation
	for the authentication.		for the authentication.
	skipping to change at page 15, line 14 ¶		skipping to change at page 15, line 14 ¶
	7. IANA Considerations		7. IANA Considerations
	This document renames some of the names in the "Transform Type 1 -		This document renames some of the names in the "Transform Type 1 -
	Encryption Algorithm Transform IDs" registry of the "Internet Key		Encryption Algorithm Transform IDs" registry of the "Internet Key
	Exchange Version 2 (IKEv2) Parameters". All the other names have		Exchange Version 2 (IKEv2) Parameters". All the other names have
	ENCR_ prefix except 3, and all other entries use names in format of		ENCR_ prefix except 3, and all other entries use names in format of
	uppercase words separated with underscores except 6. This document		uppercase words separated with underscores except 6. This document
	changes those names to match others.		changes those names to match others.
	This document requests IANA to rename following entries:		This document requests IANA to rename following entries for the AES-
			GCM cipher [RFC4106] and the Camellia cipher [RFC5529]:
	+---------------------------------------+----------------------+		+---------------------------------------+----------------------+
	| Old name | New name |		| Old name | New name |
	+---------------------------------------+----------------------+		+---------------------------------------+----------------------+
	| AES-GCM with a 8 octet ICV | ENCR_AES_GCM_8 |		| AES-GCM with a 8 octet ICV | ENCR_AES_GCM_8 |
	| AES-GCM with a 12 octet ICV | ENCR_AES_GCM_12 |		| AES-GCM with a 12 octet ICV | ENCR_AES_GCM_12 |
	| AES-GCM with a 16 octet ICV | ENCR_AES_GCM_16 |		| AES-GCM with a 16 octet ICV | ENCR_AES_GCM_16 |
	| ENCR_CAMELLIA_CCM with an 8-octet ICV | ENCR_CAMELLIA_CCM_8 |		| ENCR_CAMELLIA_CCM with an 8-octet ICV | ENCR_CAMELLIA_CCM_8 |
	| ENCR_CAMELLIA_CCM with a 12-octet ICV | ENCR_CAMELLIA_CCM_12 |		| ENCR_CAMELLIA_CCM with a 12-octet ICV | ENCR_CAMELLIA_CCM_12 |
	| ENCR_CAMELLIA_CCM with a 16-octet ICV | ENCR_CAMELLIA_CCM_16 |		| ENCR_CAMELLIA_CCM with a 16-octet ICV | ENCR_CAMELLIA_CCM_16 |
	skipping to change at page 17, line 5 ¶		skipping to change at page 17, line 10 ¶
	[RFC6989] Sheffer, Y. and S. Fluhrer, "Additional Diffie-Hellman		[RFC6989] Sheffer, Y. and S. Fluhrer, "Additional Diffie-Hellman
	Tests for the Internet Key Exchange Protocol Version 2		Tests for the Internet Key Exchange Protocol Version 2
	(IKEv2)", RFC 6989, DOI 10.17487/RFC6989, July 2013,		(IKEv2)", RFC 6989, DOI 10.17487/RFC6989, July 2013,
	<http://www.rfc-editor.org/info/rfc6989>.		<http://www.rfc-editor.org/info/rfc6989>.
	[RFC7815] Kivinen, T., "Minimal Internet Key Exchange Version 2		[RFC7815] Kivinen, T., "Minimal Internet Key Exchange Version 2
	(IKEv2) Initiator Implementation", RFC 7815,		(IKEv2) Initiator Implementation", RFC 7815,
	DOI 10.17487/RFC7815, March 2016,		DOI 10.17487/RFC7815, March 2016,
	<http://www.rfc-editor.org/info/rfc7815>.		<http://www.rfc-editor.org/info/rfc7815>.
			[RFC5529] Kato, A., Kanda, M., and S. Kanno, "Modes of Operation for
			Camellia for Use with IPsec", RFC 5529,
			DOI 10.17487/RFC5529, April 2009,
			<http://www.rfc-editor.org/info/rfc5529>.
	[IKEV2-IANA]		[IKEV2-IANA]
	"Internet Key Exchange Version 2 (IKEv2) Parameters",		"Internet Key Exchange Version 2 (IKEv2) Parameters",
	<http://www.iana.org/assignments/ikev2-parameters>.		<http://www.iana.org/assignments/ikev2-parameters>.
	[TRANSCRIPTION]		[TRANSCRIPTION]
	Bhargavan, K. and G. Leurent, "Transcript Collision		Bhargavan, K. and G. Leurent, "Transcript Collision
	Attacks: Breaking Authentication in TLS, IKE, and SSH",		Attacks: Breaking Authentication in TLS, IKE, and SSH",
	NDSS , feb 2016.		NDSS , feb 2016.
	[IEEE-802-15-4]		[IEEE-802-15-4]
End of changes. 18 change blocks.
	24 lines changed or deleted		31 lines changed or added
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