< draft-housley-spasm-eku-constraints-00.txt		draft-housley-spasm-eku-constraints-01.txt >
	INTERNET-DRAFT R. Housley		INTERNET-DRAFT R. Housley
	Intended Status: Standards Track Vigil Security		Intended Status: Standards Track Vigil Security
	Updates: RFC 5280 (if approved)		Updates: RFC 5280 (if approved)
	Expires: 14 November 2016 13 May 2016		Expires: 18 November 2016 17 May 2016
	Extended Key Usage Constraints		Extended Key Usage Constraints
	draft-housley-spasm-eku-constraints-00		draft-housley-spasm-eku-constraints-01
	Abstract		Abstract
	This document specifies the extended key usage constraints		This document specifies the extended key usage constraints
	certificate extension, which is used to place restrictions on the key		certificate extension, which is used to place restrictions on the key
	purpose identifiers that are authorized to appear in subsequent		purpose identifiers that are authorized to appear in the end-entity
	certificates in a certification path. Restrictions apply to the		certificate in a certification path. Restrictions apply to the
	extended key usage certificate extension, which is described in RFC		extended key usage certificate extension, which is described in
	5280.		RFC 5280.
	Status of this Memo		Status of this Memo
	This Internet-Draft is submitted to IETF in full conformance with the		This Internet-Draft is submitted to IETF 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), its areas, and its working groups. Note that		Task Force (IETF), its areas, and its working groups. Note that
	other groups may also distribute working documents as		other groups may also distribute working documents as Internet-
	Internet-Drafts.		Drafts.
	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."
	The list of current Internet-Drafts can be accessed at		The list of current Internet-Drafts can be accessed at
	http://www.ietf.org/1id-abstracts.html		http://www.ietf.org/1id-abstracts.html
	The list of Internet-Draft Shadow Directories can be accessed at		The list of Internet-Draft Shadow Directories can be accessed at
	skipping to change at page 2, line 27 ¶		skipping to change at page 2, line 32 ¶
	Section 4.2.1.12 of RFC 5280 [RFC5280].		Section 4.2.1.12 of RFC 5280 [RFC5280].
	1.1 Terminology		1.1 Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in RFC 2119 [RFC2119].		document are to be interpreted as described in RFC 2119 [RFC2119].
	1.2. ASN.1		1.2. ASN.1
	Certificates are generated using ASN.1 [X680], which uses the Basic		Certificates are generated using ASN.1 [X680] and the Distinguished
	Encoding Rules (BER) and the Distinguished Encoding Rules (DER)		Encoding Rules (DER) [X690].
	[X690].
			RFC 5280 [RFC5280] contains two ASN.1 modules that make use of an
			older version of the syntax (the 1988 Syntax). RFC 5912 [RFC5912]
			provides these same ASN.1 modules in the newer syntax. The appendix
			of this document provides an ASN.1 module; it employs the newer
			syntax.
	2. Extended Key Usage Constraints Certificate Extension		2. Extended Key Usage Constraints Certificate Extension
	The extended key usage (EKU) constraints certificate extension, which		The extended key usage (EKU) constraints certificate extension, which
	MUST be used only in a CA certificate, indicates the extended key		MUST be used only in a CA certificate, indicates the extended key
	usage values that are authorized to appear in subsequent certificates		usage values that are authorized to appear in subsequent certificates
	in a certification path. Restrictions apply to the extended key		in a certification path. Restrictions apply to the extended key
	usage certificate extension, which is described in Section 4.2.1.12		usage certificate extension, which is described in Section 4.2.1.12
	of RFC 5280 [RFC5280].		of RFC 5280 [RFC5280].
	Restrictions are defined in terms of permitted or excluded key		Restrictions are defined in terms of permitted or excluded key
	purpose identifiers. Any key purpose identifier matching an entry in		purpose identifiers.
	the excludedKeyPurposeIds field is invalid regardless of information
	appearing in the permittedKeyPurposeIds.		The permitted key purpose identifiers begins with the universal set.
			Then, as each certificate in the certification path is processed, the
			permitted key purpose identifiers are reduced to the intersection of
			the previous set and the ones listed in the permittedKeyPurposeIds
			field. Finally, each key purpose identifier in the extended key
			usage extension of the end-entity certificate MUST appear in the
			permitted key purpose identifiers set.
			The excluded key purpose identifiers begins with the empty set.
			Then, as each certificate in the certification path is processed, the
			excluded key purpose identifiers are increased to the union of the
			previous set and the ones listed in the excludedKeyPurposeIds field.
			Finally, each key purpose identifier in the extended key usage
			extension of the end-entity certificate MUST NOT appear in the
			excluded key purpose identifiers set.
			The special key purpose identifier anyExtendedKeyUsage is not treated
			differently than any other key purpose identifier in processing the
			constraints. If the anyExtendedKeyUsage key purpose identifier
			appears in the extended key usage extension of the end-entity
			certificate, then the anyExtendedKeyUsage key purpose identifier MUST
			appear in the permitted key purpose identifiers set and the
			anyExtendedKeyUsage key purpose identifier MUST NOT appear in the
			excluded key purpose identifiers set.
	Conforming CAs MUST mark this extension as critical, and conforming		Conforming CAs MUST mark this extension as critical, and conforming
	CAs MUST NOT issue certificates where this extension is an empty		CAs MUST NOT issue certificates where this extension is an empty
	sequence. That is, either the permittedKeyPurposeIds field or the		sequence. That is, at least one of the permittedKeyPurposeIds field
	excludedKeyPurposeIds field MUST be present.		or the excludedKeyPurposeIds field MUST be present.
	Conforming applications MUST be able to process this extension. If		Conforming applications MUST be able to process this extension. If
	any CA certificate in the certification path includes an EKU		any CA certificate in the certification path includes an extended key
	constraints extension that is marked as critical, and the end-entity		usage constraints extension and the end-entity certificate includes
	certificate includes an extended key usage certificate extension,		an extended key usage certificate extension, then the application
	then the application MUST either process the EKU constraint or reject		MUST either process the extended key usage extension constraint or
	the certificate.		reject the certificate.
	ekuConstraints EXTENSION ::= { SYNTAX EKUConstraints		ext-ExtKeyUsageConstraints EXTENSION ::= {
			SYNTAX EKUConstraints
	IDENTIFIED BY id-ce-ekuConstraints }		IDENTIFIED BY id-ce-ekuConstraints }
	id-ce-ekuConstraints OBJECT IDENTIFIER ::= { id-ce TBD }		id-ce-ekuConstraints OBJECT IDENTIFIER ::= { id-pe TBD }
	EKUConstraints ::= SEQUENCE {		EKUConstraints ::= SEQUENCE {
	permittedKeyPurposeIds [0] KeyPurposeIds OPTIONAL,		permittedKeyPurposeIds [0] KeyPurposeIds OPTIONAL,
	excludedKeyPurposeIds [1] KeyPurposeIds OPTIONAL }		excludedKeyPurposeIds [1] KeyPurposeIds OPTIONAL }
			( WITH COMPONENTS { ..., permittedKeyPurposeIds PRESENT } |
			WITH COMPONENTS { ..., excludedKeyPurposeIds PRESENT } )
	KeyPurposeIds ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId		KeyPurposeIds ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
	3. Basic Path Validation		3. Basic Path Validation
	Certification path validation is described in Section 6.1 of RFC 5280		Certification path validation is described in Section 6.1 of RFC 5280
	[RFC5280]. Certification path processing verifies the binding		[RFC5280]. Certification path processing verifies the binding
	between the subject name and the subject public key. The binding is		between the subject name and the subject public key. The binding is
	limited by constraints that are specified in the certificates that		limited by constraints that are specified in the certificates that
	comprise the path and inputs that are specified by the relying party.		comprise the path and inputs that are specified by the relying party.
	skipping to change at page 3, line 49 ¶		skipping to change at page 4, line 36 ¶
	all of the key purpose identifiers in the end-entity certificate		all of the key purpose identifiers in the end-entity certificate
	MUST be included in this set. If the set is empty, then the		MUST be included in this set. If the set is empty, then the
	certification path will be considered invalid if the end-entity		certification path will be considered invalid if the end-entity
	certificate includes an extended key usage extension. The		certificate includes an extended key usage extension. The
	initial value is a special value that represents the universal		initial value is a special value that represents the universal
	set.		set.
	(m) excluded_key_purpose_ids: a set of key purpose identifiers; the		(m) excluded_key_purpose_ids: a set of key purpose identifiers; the
	key purpose identifiers in the end-entity certificate MUST NOT		key purpose identifiers in the end-entity certificate MUST NOT
	be included in this set. If the set is empty, then no key		be included in this set. If the set is empty, then no key
	purpose identifiers are excluded. The initial value is a is the		purpose identifiers are excluded. The initial value is the
	empty set.		empty set.
	3.3. Basic Certificate Processing		3.3. Basic Certificate Processing
	No additional processing steps are needed.		No additional processing steps are needed.
	3.4. Preparation for Certificate i+1		3.4. Preparation for Certificate i+1
	One additional processing step is needed.		One additional processing step is needed.
	skipping to change at page 4, line 36 ¶		skipping to change at page 5, line 32 ¶
	3.5. Wrap-Up Procedure		3.5. Wrap-Up Procedure
	One additional processing step is needed.		One additional processing step is needed.
	(h) If the EKU extension is included in the end-entity certificate,		(h) If the EKU extension is included in the end-entity certificate,
	then confirm that the values meet the restrictions in the		then confirm that the values meet the restrictions in the
	permitted_key_purpose_ids and excluded_key_purpose_ids state		permitted_key_purpose_ids and excluded_key_purpose_ids state
	variables as follows:		variables as follows:
	(1) If permitted_key_purpose_ids state variable is not special		(1) If permitted_key_purpose_ids state variable is empty, then
	value that represents the universal set, then confirm that		return a failure indication and an appropriate reason.
	all of the key purpose identifiers are present in the set.
	If any are missing, then returning a failure indication and
	an appropriate reason.
	(2) If excluded_key_purpose_ids state variable is not empty,		(2) If excluded_key_purpose_ids state variable is not empty,
	then confirm that none of the key purpose identifiers are		then confirm that none of the key purpose identifiers in
	present in the set. If any are present, then returning a		the state variable are present in the end-entity
	failure indication and an appropriate reason.		certificate. If any are present, then return a failure
			indication and an appropriate reason.
			(3) If permitted_key_purpose_ids state variable is not the
			special value that represents the universal set, then
			confirm that all of the key purpose identifiers in the end-
			entity certificate are present in the state variable. If
			any are missing, then return a failure indication and an
			appropriate reason.
	3.6. Outputs		3.6. Outputs
	No additional output values are returned.		No additional output values are returned.
	4. IANA Considerations		4. IANA Considerations
	Please assign an object identifier for the certificate extension		Please assign an object identifier for the certificate extension
	specified in this document. Once the ASN.1 module is added, then an		specified in this document. Once the ASN.1 module is added, then an
	object identifier for that will be needed too.		object identifier for that will be needed too.
	5. Security Considerations		5. Security Considerations
	TBD		When a CA includes the extended key usage constraints certificate
			extension for a subordinate CA, the OCSPSigning key purpose
			identifier SHOULD be included in the permittedKeyPurposeIds field to
			enable the issuance of delegated OCSP Responder certificates.
	6. Normative References		6. Normative References
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, DOI		Requirement Levels", BCP 14, RFC 2119, DOI
	10.17487/RFC2119, March 1997, <http://www.rfc-		10.17487/RFC2119, March 1997, <http://www.rfc-
	editor.org/info/rfc2119>.		editor.org/info/rfc2119>.
	[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,		[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
	Housley, R., and W. Polk, "Internet X.509 Public Key		Housley, R., and W. Polk, "Internet X.509 Public Key
	Infrastructure Certificate and Certificate Revocation List		Infrastructure Certificate and Certificate Revocation List
	(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,		(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
	<http://www.rfc-editor.org/info/rfc5280>.		<http://www.rfc-editor.org/info/rfc5280>.
			[X680] ITU-T, "Information technology -- Abstract Syntax Notation
			One (ASN.1): Specification of basic notation", ITU-T
			Recommendation X.680, 2002.
			[X690] ITU-T, "Information technology -- ASN.1 encoding rules:
			Specification of Basic Encoding Rules (BER), Canonical
			Encoding Rules (CER) and Distinguished Encoding Rules
			(DER)", ITU-T Recommendation X.690, 2002.
			7. Informative References
			[RFC5912] Hoffman, P. and J. Schaad, "New ASN.1 Modules for the
			Public Key Infrastructure Using X.509 (PKIX)", RFC 5912,
			DOI 10.17487/RFC5912, June 2010, <http://www.rfc-
			editor.org/info/rfc5912>.
	Appendix: ASN.1 Module		Appendix: ASN.1 Module
	TBD		EKUConstraints2016 { iso(1) identified-organization(3) dod(6)
			internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
			id-mod-ekuConstraints2016(TBD) }
			DEFINITIONS IMPLICIT TAGS ::= BEGIN
			-- EXPORTS ALL --
			IMPORTS
			EXTENSION
			FROM PKIX-CommonTypes-2009
			{ iso(1) identified-organization(3) dod(6) internet(1)
			security(5) mechanisms(5) pkix(7) id-mod(0)
			id-mod-pkixCommon-02(57) }
			id-pe
			FROM PKIX1Explicit-2009
			{ iso(1) identified-organization(3) dod(6) internet(1)
			security(5) mechanisms(5) pkix(7) id-mod(0)
			id-mod-pkix1-explicit-02(51) }
			KeyPurposeId
			FROM PKIX1Implicit-2009
			{ iso(1) identified-organization(3) dod(6) internet(1)
			security(5) mechanisms(5) pkix(7) id-mod(0)
			id-mod-pkix1-implicit-02(59) } ;
			MoreCertExtensions EXTENSION ::= {
			ext-ExtKeyUsageConstraints, ... }
			ext-ExtKeyUsageConstraints EXTENSION ::= {
			SYNTAX EKUConstraints
			IDENTIFIED BY id-ce-ekuConstraints }
			id-ce-ekuConstraints OBJECT IDENTIFIER ::= { id-pe TBD }
			EKUConstraints ::= SEQUENCE {
			permittedKeyPurposeIds [0] KeyPurposeIds OPTIONAL,
			excludedKeyPurposeIds [1] KeyPurposeIds OPTIONAL }
			( WITH COMPONENTS { ..., permittedKeyPurposeIds PRESENT } |
			WITH COMPONENTS { ..., excludedKeyPurposeIds PRESENT } )
			KeyPurposeIds ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
			END
			Acknowledgements
			Many thanks to review and insightful comments from Santosh Chokhani,
			Stephen Farrell, Tom Gindin, Sean Leonard, Michael Richardson, Jim
			Schaad, and Mike St.Johns.
	Author's Address		Author's Address
	Russell Housley		Russell Housley
	Vigil Security, LLC		Vigil Security, LLC
	918 Spring Knoll Drive		918 Spring Knoll Drive
	Herndon, VA 20170		Herndon, VA 20170
	USA		USA
	EMail: housley@vigilsec.com		EMail: housley@vigilsec.com
End of changes. 17 change blocks.
	34 lines changed or deleted		139 lines changed or added
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