< draft-bormann-cbor-tags-oid-01.txt		draft-bormann-cbor-tags-oid-02.txt >
	Network Working Group C. Bormann		Network Working Group C. Bormann
	Internet-Draft Universitaet Bremen TZI		Internet-Draft Universitaet Bremen TZI
	Intended status: Standards Track S. Leonard		Intended status: Standards Track S. Leonard
	Expires: January 7, 2016 Penango, Inc.		Expires: July 9, 2016 Penango, Inc.
	July 06, 2015		January 06, 2016
	Concise Binary Object Representation (CBOR) Tags for		Concise Binary Object Representation (CBOR) Tags for
	ASN.1 Object Identifiers		ASN.1 Object Identifiers
	draft-bormann-cbor-tags-oid-01		draft-bormann-cbor-tags-oid-02
	Abstract		Abstract
	The Concise Binary Object Representation (CBOR, RFC 7049) is a data		The Concise Binary Object Representation (CBOR, RFC 7049) is a data
	format whose design goals include the possibility of extremely small		format whose design goals include the possibility of extremely small
	code size, fairly small message size, and extensibility without the		code size, fairly small message size, and extensibility without the
	need for version negotiation.		need for version negotiation.
	The present document makes use of this extensibility to define CBOR		The present document makes use of this extensibility to define CBOR
	tags <<O>> and <<R>> [values TBD] for ASN.1 object identifiers. It		tags <<O>> and <<R>> [values TBD] for ASN.1 object identifiers. It
	skipping to change at page 1, line 40 ¶		skipping to change at page 1, line 40 ¶
	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 January 7, 2016.		This Internet-Draft will expire on July 9, 2016.
	Copyright Notice		Copyright Notice
	Copyright (c) 2015 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
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	skipping to change at page 2, line 21 ¶		skipping to change at page 2, line 21 ¶
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. ASN.1 Object Identifiers . . . . . . . . . . . . . . . . . . 3		2. ASN.1 Object Identifiers . . . . . . . . . . . . . . . . . . 3
	3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 4		3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 4
	4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 6		4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 6
	5. Diagnostic Notation . . . . . . . . . . . . . . . . . . . . . 7		5. Diagnostic Notation . . . . . . . . . . . . . . . . . . . . . 7
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 8		7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
	8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9		8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
	1. Introduction		1. Introduction
	The Concise Binary Object Representation (CBOR, [RFC7049]) provides		The Concise Binary Object Representation (CBOR, [RFC7049]) provides
	for the interchange of structured data without a requirement for a		for the interchange of structured data without a requirement for a
	pre-agreed schema. RFC 7049 defines a basic set of data types, as		pre-agreed schema. RFC 7049 defines a basic set of data types, as
	well as a tagging mechanism that enables extending the set of data		well as a tagging mechanism that enables extending the set of data
	types supported via an IANA registry.		types supported via an IANA registry.
	Many IETF protocols carry ASN.1 object identifiers, originally		Many IETF protocols carry ASN.1 object identifiers, originally
	defined in 1988 [CCITT.X208.1988] and most recently in 2008 [X.680].		defined in 1988 [CCITT.X208.1988] and most recently in 2008 [X.680].
	The ASN.1 Basic Encoding Rules (BER, [X.690]) specifies the binary		The ASN.1 Basic Encoding Rules (BER, [X.690]) specify the binary
	encodings of both ASN.1 object identifiers and relative object		encodings of both ASN.1 object identifiers and relative object
	identifiers. The contents of these encodings can be carried in a		identifiers. The contents of these encodings can be carried in a
	CBOR byte string.		CBOR byte string.
	This document defines two CBOR tags that cover the two kinds of ASN.1		This document defines two CBOR tags that cover the two kinds of ASN.1
	object identifiers encoded in this way. It is intended as the		object identifiers encoded in this way. It is intended as the
	reference document for the IANA registration of the tags so defined.		reference document for the IANA registration of the tags so defined.
	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", "NOT RECOMMENDED", "MAY", and
	document are to be interpreted as described in RFC 2119 [RFC2119].		"OPTIONAL" in this document are to be interpreted as described in RFC
			2119 [RFC2119].
	The terminology of RFC 7049 applies; in particular the term "byte" is		The terminology of RFC 7049 applies; in particular the term "byte" is
	used in its now customary sense as a synonym for "octet".		used in its now customary sense as a synonym for "octet".
	2. ASN.1 Object Identifiers		2. ASN.1 Object Identifiers
	The International Object Identifier tree [X.660] is a hierarchically		The International Object Identifier tree [X.660] is a hierarchically
	managed space of identifiers, each of which is uniquely represented		managed space of identifiers, each of which is uniquely represented
	as a sequence of unsigned integers ("sub-identifiers") [X.680].		as a sequence of unsigned integers ("sub-identifiers") [X.680].
	While these sequences can easily be represented in CBOR arrays of		While these sequences can easily be represented in CBOR arrays of
	unsigned integers, a more compact representation can often be		unsigned integers, a more compact representation can often be
	achieved by adopting the widely used representation of ASN.1 object		achieved by adopting the widely used representation of ASN.1 object
	identifiers defined in BER; this representation may also be more		identifiers defined in BER; this representation may also be more
	amenable to processing by other software making use of ASN.1 object		amenable to processing by other software making use of ASN.1 object
	identifiers.		identifiers.
	BER represents the sequence of unsigned integers by concatenating		BER represents the sequence of unsigned integers by concatenating
	self-delimiting [RFC6256] representations of each of the sub-		self-delimiting [RFC6256] representations of each of the sub-
	identifier in sequence.		identifiers in sequence.
	ASN.1 distinguishes absolute object identifiers (ASN.1 Type "OBJECT		ASN.1 distinguishes absolute object identifiers (ASN.1 Type "OBJECT
	IDENTIFIER"), which begin at a root arc ([X.660] Clause 3.5.21), from		IDENTIFIER"), which begin at a root arc ([X.660] Clause 3.5.21), from
	relative object identifiers (ASN.1 Type "RELATIVE-OID"), which begin		relative object identifiers (ASN.1 Type "RELATIVE-OID"), which begin
	relative to some object identifier known from context ([X.680] Clause		relative to some object identifier known from context ([X.680] Clause
	3.8.63). As a special optimization, BER combines the first two		3.8.63). As a special optimization, BER combines the first two
	integers in an absolute object identifier into one numeric identifier		integers in an absolute object identifier into one numeric identifier
	by making use of the property of the hierarchy that the first arc has		by making use of the property of the hierarchy that the first arc has
	only three integer values (0, 1, and 2), and the second arcs under 0		only three integer values (0, 1, and 2), and the second arcs under 0
	and 1 are limited to the integer values between 0 and 39. (The root		and 1 are limited to the integer values between 0 and 39. (The root
	skipping to change at page 4, line 48 ¶		skipping to change at page 4, line 48 ¶
	also to be treated as indivisible units: They MUST be encoded in		also to be treated as indivisible units: They MUST be encoded in
	definite-length form; indefinite-length form is treated as an		definite-length form; indefinite-length form is treated as an
	encoding error (and the same considerations as above apply). (An		encoding error (and the same considerations as above apply). (An
	added convenience is that CBOR encodings can be searched through		added convenience is that CBOR encodings can be searched through
	efficiently for specific OIDs or relative OIDs, without initiating		efficiently for specific OIDs or relative OIDs, without initiating
	the decoding process.)		the decoding process.)
	3. Examples		3. Examples
	In the following examples, we are using tag number 6 for <<O>> and		In the following examples, we are using tag number 6 for <<O>> and
	tag number 7 for <<O>>. See Section 6.1.		tag number 7 for <<R>>. See Section 6.1.
	3.1. Encoding of the SHA-256 OID		3.1. Encoding of the SHA-256 OID
	ASN.1 Value Notation		ASN.1 Value Notation
	{ joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101)		{ joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101)
	csor(3) nistalgorithm(4) hashalgs(2) sha256(1) }		csor(3) nistalgorithm(4) hashalgs(2) sha256(1) }
	Dotted Decimal Notation (also XML Value Notation)		Dotted Decimal Notation (also XML Value Notation)
	2.16.840.1.101.3.4.2.1		2.16.840.1.101.3.4.2.1
	skipping to change at page 5, line 35 ¶		skipping to change at page 5, line 35 ¶
	Figure 2: SHA-256 OID in CBOR		Figure 2: SHA-256 OID in CBOR
	3.2. Encoding of a UUID OID		3.2. Encoding of a UUID OID
	UUID		UUID
	8b0d1a20-dcc5-11d9-bda9-0002a5d5c51b		8b0d1a20-dcc5-11d9-bda9-0002a5d5c51b
	ASN.1 Value Notation		ASN.1 Value Notation
	{ joint-iso-itu-t(2) uuid(25)		{ joint-iso-itu-t(2) uuid(25)
	geomicaGPAS(2957291539512641589387040445673640841648) }		geomicaGPAS(184830721219540099336690027854602552603) }
	Dotted Decimal Notation (also XML Value Notation)		Dotted Decimal Notation (also XML Value Notation)
	2.25.2957291539512641589387040445673640841648		2.25.184830721219540099336690027854602552603
	06 # UNIVERSAL TAG 6		06 # UNIVERSAL TAG 6
	14 # 20 bytes, primitive		14 # 20 bytes, primitive
	69 A2 E1 D1 D1 83 B9 C5 88 F6 B7 DA C8 80 85 A5 EA F1 A3 30		69 82 96 8D 8D 88 9B CC A8 C7 B3 BD D4 C0 80 AA AE D7 8A 1B
	# | 2957291539512641589387040445673640841648		# | 184830721219540099336690027854602552603
	# 2.25		# 2.25
	Figure 3: UUID in an object identifier, in BER		Figure 3: UUID in an object identifier, in BER
	C6 # 0b110_00110: mt 6, tag 6		C6 # 0b110_00110: mt 6, tag 6
	54 # 0b010_10100: mt 2, 20 bytes		54 # 0b010_10100: mt 2, 20 bytes
	69 A2 E1 D1 D1 83 B9 C5 88 F6 B7 DA C8 80 85 A5 EA F1 A3 30`		69 82 96 8D 8D 88 9B CC A8 C7 B3 BD D4 C0 80 AA AE D7 8A 1B
	Figure 4: UUID in an object identifier, in CBOR		Figure 4: UUID in an object identifier, in CBOR
	3.3. Encoding of a MIB Relative OID		3.3. Encoding of a MIB Relative OID
	Given some OID (e.g., "lowpanMib", assumed to be "1.3.6.1.2.1.226"		Given some OID (e.g., "lowpanMib", assumed to be "1.3.6.1.2.1.226"
	[RFC7388]), to which the following is added:		[RFC7388]), to which the following is added:
	ASN.1 Value Notation (not suitable for diagnostic notation)		ASN.1 Value Notation (not suitable for diagnostic notation)
	{ lowpanObjects(1) lowpanStats(1) lowpanOutTransmits(29) }		{ lowpanObjects(1) lowpanStats(1) lowpanOutTransmits(29) }
	skipping to change at page 6, line 49 ¶		skipping to change at page 6, line 49 ¶
	based on BER; using a different encoding might not be aligned with		based on BER; using a different encoding might not be aligned with
	these expectations. If additional information about an OID is		these expectations. If additional information about an OID is
	desired, lookup services such as the OID Resolution Service (ORS,		desired, lookup services such as the OID Resolution Service (ORS,
	[X.672]) and the OID Repository (oid-info.com, [OIDINFO]) are		[X.672]) and the OID Repository (oid-info.com, [OIDINFO]) are
	available.		available.
	This specification allocates two numbers out of the single-byte tag		This specification allocates two numbers out of the single-byte tag
	space. This use of code point space is justified by the wide use of		space. This use of code point space is justified by the wide use of
	object identifiers in data interchange. For most common OIDs in use		object identifiers in data interchange. For most common OIDs in use
	(namely those whose contents encode to less than 24 bytes), the CBOR		(namely those whose contents encode to less than 24 bytes), the CBOR
	encoding will match the efficiency of [X.690].		encoding will match the efficiency of [X.690]. (This preliminary
			conclusion is likely to generate some discussion, see Section 6.1.)
	5. Diagnostic Notation		5. Diagnostic Notation
	Implementers will likely want to see OIDs and relative OIDs in their		Implementers will likely want to see OIDs and relative OIDs in their
	"natural forms" (as sequences of unsigned integers) for diagnostic		"natural forms" (as sequences of decimal unsigned integers) for
	purposes. Accordingly, this section defines additional syntactic		diagnostic purposes. Accordingly, this section defines additional
	elements that can be used in conjunction with the diagnostic notation		syntactic elements that can be used in conjunction with the
	described in Section 6 of [RFC7049].		diagnostic notation described in Section 6 of [RFC7049].
	An object identifier may be written in ASN.1 value notation (with		An object identifier may be written in ASN.1 value notation (with
	enclosing braces and secondary identifiers), or in dotted decimal		enclosing braces and secondary identifiers), or in dotted decimal
	notation with at least three arcs. Both examples are shown in		notation with at least three arcs. Both examples are shown in
	Section 3. The surrounding tag notation is optional. The ASN.1		Section 3. The surrounding tag notation is optional. The ASN.1
	value notation for OIDs does not overlap with JSON object notation		value notation for OIDs does not overlap with JSON object notation
	for CBOR maps, because at least two arcs are required for a valid		for CBOR maps, because at least two arcs are required for a valid
	OID.		OID.
	A relative object identifier may be written in dotted decimal		A relative object identifier may be written in dotted decimal
	notation only, prefixed with a dot as shown in Section 3.3. The		notation only, prefixed with a dot as shown in Section 3.3. The
	surrounding tag notation is optional. ASN.1 value notation is not		surrounding tag notation is optional. ASN.1 value notation is not
	suitable for the diagnostic notation of relative OIDs because		suitable for the diagnostic notation of relative OIDs because
	knowledge of the base OID cannot be determined from the encoding		knowledge of the base OID cannot be determined from the encoding
	alone; such knowledge requires a protocol on top of CBOR.		alone; such knowledge requires a protocol on top of CBOR.
	The notation in this section may be employed in addition to the basic		The notation in this section may be employed in addition to the basic
	notation, which would be a tagged binary string.		notation, which would be a tagged binary string.
	+------------------------------+----------------+------------+		+------------------------------+--------------+------------+
	| RFC 7049 diagnostic notation | 6(h'2b030601') | 7(h'0601') |		| RFC 7049 diagnostic notation | 6(h'2b0601') | 7(h'0601') |
	+------------------------------+----------------+------------+		+------------------------------+--------------+------------+
	| Dotted decimal notation | 1.3.6.1 | .6.1 |		| Dotted decimal notation | 1.3.6.1 | .6.1 |
	| ASN.1 value notation | {1 3 6 1} | -N/A- |		| ASN.1 value notation | {1 3 6 1} | -N/A- |
	+------------------------------+----------------+------------+		+------------------------------+--------------+------------+
	Table 1: Examples for extended diagnostic notation		Table 1: Examples for extended diagnostic notation
	6. IANA Considerations		6. IANA Considerations
	(This section to be edited by the RFC editor.)		(This section to be edited by the RFC editor.)
	IANA is requested to assign the CBOR tags in Table 2, with the		IANA is requested to assign the CBOR tags in Table 2, with the
	present document as the specification reference.		present document as the specification reference.
	skipping to change at page 9, line 30 ¶		skipping to change at page 9, line 30 ¶
	certainly be able to cause the accumulator to overflow. Compact and		certainly be able to cause the accumulator to overflow. Compact and
	efficient techniques for such conversions, such as the double dabble		efficient techniques for such conversions, such as the double dabble
	algorithm [DOUBLEDABBLE] are well-known in the art; their application		algorithm [DOUBLEDABBLE] are well-known in the art; their application
	to this field is left as an exercise to the reader.		to this field is left as an exercise to the reader.
	8. References		8. References
	8.1. Normative References		8.1. 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, March 1997.		Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
			RFC2119, March 1997,
			<http://www.rfc-editor.org/info/rfc2119>.
	[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object		[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
	Representation (CBOR)", RFC 7049, October 2013.		Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
			October 2013, <http://www.rfc-editor.org/info/rfc7049>.
	[X.660] International Telecommunications Union, "Information		[X.660] International Telecommunications Union, "Information
	technology -- Procedures for the operation of object		technology -- Procedures for the operation of object
	identifier registration authorities: General procedures		identifier registration authorities: General procedures
	and top arcs of the international object identifier tree",		and top arcs of the international object identifier tree",
	ITU-T Recommendation X.660, July 2011.		ITU-T Recommendation X.660, July 2011.
	[X.680] International Telecommunications Union, "Information		[X.680] International Telecommunications Union, "Information
	technology -- Abstract Syntax Notation One (ASN.1):		technology -- Abstract Syntax Notation One (ASN.1):
	Specification of basic notation", ITU-T Recommendation		Specification of basic notation", ITU-T Recommendation
	skipping to change at page 10, line 29 ¶		skipping to change at page 10, line 35 ¶
	<http://www.oid-info.com/>.		<http://www.oid-info.com/>.
	[PKILCAKE]		[PKILCAKE]
	Kaminsky, D., Patterson, M., and L. Sassaman, "PKI Layer		Kaminsky, D., Patterson, M., and L. Sassaman, "PKI Layer
	Cake: New Collision Attacks Against the Global X.509		Cake: New Collision Attacks Against the Global X.509
	Infrastructure", FC 2010, Lecture Notes in Computer		Infrastructure", FC 2010, Lecture Notes in Computer
	Science 6052 289-303, DOI: 10.1007/978-3-642-14577-3_22,		Science 6052 289-303, DOI: 10.1007/978-3-642-14577-3_22,
	January 2010, <http://dl.acm.org/citation.cfm?id=2163593>.		January 2010, <http://dl.acm.org/citation.cfm?id=2163593>.
	[RFC6256] Eddy, W. and E. Davies, "Using Self-Delimiting Numeric		[RFC6256] Eddy, W. and E. Davies, "Using Self-Delimiting Numeric
	Values in Protocols", RFC 6256, May 2011.		Values in Protocols", RFC 6256, DOI 10.17487/RFC6256, May
			2011, <http://www.rfc-editor.org/info/rfc6256>.
	[RFC7388] Schoenwaelder, J., Sehgal, A., Tsou, T., and C. Zhou,		[RFC7388] Schoenwaelder, J., Sehgal, A., Tsou, T., and C. Zhou,
	"Definition of Managed Objects for IPv6 over Low-Power		"Definition of Managed Objects for IPv6 over Low-Power
	Wireless Personal Area Networks (6LoWPANs)", RFC 7388,		Wireless Personal Area Networks (6LoWPANs)", RFC 7388, DOI
	October 2014.		10.17487/RFC7388, October 2014,
			<http://www.rfc-editor.org/info/rfc7388>.
	[X.672] International Telecommunications Union, "Information		[X.672] International Telecommunications Union, "Information
	technology -- Open systems interconnection -- Object		technology -- Open systems interconnection -- Object
	identifier resolution system", ITU-T Recommendation X.672,		identifier resolution system", ITU-T Recommendation X.672,
	August 2010.		August 2010.
	Authors' Addresses		Authors' Addresses
	Carsten Bormann		Carsten Bormann
	Universitaet Bremen TZI		Universitaet Bremen TZI
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