Internet DRAFT - draft-ietf-cbor-tags-oid
draft-ietf-cbor-tags-oid
Network Working Group C. Bormann
Internet-Draft Universität Bremen TZI
Intended status: Standards Track 21 May 2021
Expires: 22 November 2021
Concise Binary Object Representation (CBOR) Tags for Object Identifiers
draft-ietf-cbor-tags-oid-08
Abstract
The Concise Binary Object Representation (CBOR, RFC 8949) is a data
format whose design goals include the possibility of extremely small
code size, fairly small message size, and extensibility without the
need for version negotiation.
The present document defines CBOR tags for object identifiers (OIDs).
It is intended as the reference document for the IANA registration of
the CBOR tags so defined.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 22 November 2021.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Object Identifiers . . . . . . . . . . . . . . . . . . . . . 4
2.1. Requirements on the byte string being tagged . . . . . . 5
2.2. Preferred Serialization Considerations . . . . . . . . . 6
2.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . 6
3. Basic Examples . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. Encoding of the SHA-256 OID . . . . . . . . . . . . . . . 7
3.2. Encoding of a MIB Relative OID . . . . . . . . . . . . . 7
4. Tag Factoring with Arrays and Maps . . . . . . . . . . . . . 8
4.1. Preferred Serialization Considerations . . . . . . . . . 8
4.2. Tag Factoring Example: X.500 Distinguished Name . . . . . 9
5. CDDL Control Operators . . . . . . . . . . . . . . . . . . . 10
6. CDDL typenames . . . . . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7.1. CBOR Tags . . . . . . . . . . . . . . . . . . . . . . . . 11
7.2. CDDL Control Operators . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
9.1. Normative References . . . . . . . . . . . . . . . . . . 13
9.2. Informative References . . . . . . . . . . . . . . . . . 14
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 15
A.1. Changes from -06 to -07 . . . . . . . . . . . . . . . . . 15
A.2. Changes from -05 to -06 . . . . . . . . . . . . . . . . . 15
A.3. Changes from -04 to -05 . . . . . . . . . . . . . . . . . 15
A.4. Changes from -03 to -04 . . . . . . . . . . . . . . . . . 15
A.5. Changes from -02 to -03 . . . . . . . . . . . . . . . . . 15
A.6. Changes from -01 to -02 . . . . . . . . . . . . . . . . . 15
A.7. Changes from -00 to -01 . . . . . . . . . . . . . . . . . 15
A.8. Changes from -07 (bormann) to -00 (ietf) . . . . . . . . 16
A.9. Changes from -06 to -07 . . . . . . . . . . . . . . . . . 16
A.10. Changes from -05 to -06 . . . . . . . . . . . . . . . . . 16
A.11. Changes from -04 to -05 . . . . . . . . . . . . . . . . . 16
A.12. Changes from -03 to -04 . . . . . . . . . . . . . . . . . 16
A.13. Changes from -02 to -03 . . . . . . . . . . . . . . . . . 16
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 17
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 17
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Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
The Concise Binary Object Representation (CBOR, [RFC8949]) provides
for the interchange of structured data without a requirement for a
pre-agreed schema. [RFC8949] defines a basic set of data types, as
well as a tagging mechanism that enables extending the set of data
types supported via an IANA registry.
The present document defines CBOR tags for object identifiers (OIDs,
[X.660]), which many IETF protocols carry. The ASN.1 Basic Encoding
Rules (BER, [X.690]) specify binary encodings of both (absolute)
object identifiers and relative object identifiers. The contents of
these encodings (the "value" part of BER's type-length-value
structure) can be carried in a CBOR byte string. This document
defines two CBOR tags that cover the two kinds of ASN.1 object
identifiers encoded in this way, and a third one to enable a common
optimization. The tags can also be applied to arrays and maps to
efficiently tag all elements of an array or all keys of a map. It is
intended as the reference document for the IANA registration of the
tags so defined.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The terminology of [RFC8949] applies; in particular the term "byte"
is used in its now customary sense as a synonym for "octet". The
verb "to tag (something)" is used to express the construction of a
CBOR tag with the object (something) as the tag content and a tag
number indicated elsewhere in the sentence (for instance in a "with"
clause, or by the shorthand "an NNN tag" for "a tag with tag number
NNN"). The term "SDNV" (Self-Delimiting Numeric Value) is used as
defined in [RFC6256], with the additional restriction detailed in
Section 2.1 (no leading zeros).
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2. Object Identifiers
The International Object Identifier tree [X.660] is a hierarchically
managed space of identifiers, each of which is uniquely represented
as a sequence of unsigned integer values [X.680]. (These integer
values are called "primary integer values" in X.660 because they can
be accompanied by (not necessarily unambiguous) secondary
identifiers. We ignore the latter and simply use the term "integer
values" here, occasionally calling out their unsignedness. We also
use the term "arc" when the focus is on the edge of the tree labeled
by such an integer value, as well as in the sense of a "long arc",
i.e., a (sub)sequence of such integer values.)
While these sequences can easily be represented in CBOR arrays of
unsigned integers, a more compact representation can often be
achieved by adopting the widely used representation of object
identifiers defined in BER; this representation may also be more
amenable to processing by other software that makes use of object
identifiers.
BER represents the sequence of unsigned integers by concatenating
self-delimiting [RFC6256] representations of each of the integer
values in sequence.
ASN.1 distinguishes absolute object identifiers (ASN.1 Type "OBJECT
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 to some object identifier known from context ([X.680] Clause
3.8.63). As a special optimization, BER combines the first two
integers in an absolute object identifier into one numeric identifier
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
and 1 are limited to the integer values between 0 and 39. (The root
arc "joint-iso-itu-t(2)" has no such limitations on its second arc.)
If X and Y are the first two integer values, the single integer value
actually encoded is computed as:
X * 40 + Y
The inverse transformation (again making use of the known ranges of X
and Y) is applied when decoding the object identifier.
Since the semantics of absolute and relative object identifiers
differ, and it is very common for companies to use self-assigned
numbers under the arc "1.3.6.1.4.1" (IANA Private Enterprise Number
OID, [IANA.enterprise-numbers]) that adds 5 fixed bytes to an encoded
OID value, this specification defines three tags, collectively called
the "OID tags" here:
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Tag number TBD111: used to tag a byte string as the [X.690] encoding
of an absolute object identifier (simply "object identifier" or
"OID").
Tag number TBD110: used to tag a byte string as the [X.690] encoding
of a relative object identifier (also "relative OID"). Since the
encoding of each number is the same as for [RFC6256] Self-Delimiting
Numeric Values (SDNVs), this tag can also be used for tagging a byte
string that contains a sequence of zero or more SDNVs (or a more
application-specific tag can be created for such an application).
Tag TBD112: structurally like TBD110, but understood to be relative
to "1.3.6.1.4.1" (IANA Private Enterprise Number OID,
[IANA.enterprise-numbers]). Hence, the semantics of the result are
that of an absolute object identifier.
2.1. Requirements on the byte string being tagged
To form a valid tag, a byte string tagged with TBD111, TBD110, or
TBD112 MUST be syntactically valid contents (the value part) for a
BER representation of an object identifier (Sections 8.19, 8.20, and
8.20 of [X.690], respectively): A concatenation of zero or more SDNV
values, where each SDNV value is a sequence of one or more bytes that
all have their most significant bit set, except for the last byte,
where it is unset. Also, the first byte of each SDNV cannot be a
leading zero in SDNV's base-128 arithmetic, so it cannot take the
value 0x80 (bullet (c) in Section 8.1.2.4.2 of [X.690]).
In other words:
* the byte string's first byte, and any byte that follows a byte
that has the most significant bit unset, MUST NOT be 0x80 (this
requirement requires expressing the integer values in their
shortest form, with no leading zeroes)
* the byte string's last byte MUST NOT have the most significant bit
set (this requirement excludes an incomplete final integer value)
If either of these invalid conditions are encountered, the tag is
invalid.
[X.680] restricts RELATIVE-OID values to have at least one arc, i.e.,
their encoding would have at least one SDNV. This specification
permits empty relative object identifiers; they may still be excluded
by application semantics.
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To facilitate the search for specific object ID values, it is
RECOMMENDED that definite length encoding (see Section 3.2.3 of
[RFC8949]) is used for the byte strings used as tag content for these
tags.
The valid set of byte strings can also be expressed using regular
expressions on bytes, using no specific notation but resembling
[PCRE]. Unlike typical regular expressions that operate on character
sequences, the following regular expressions take bytes as their
domain, so they can be applied directly to CBOR byte strings.
For byte strings with tag TBD111:
"/^(([\x81-\xFF][\x80-\xFF]*)?[\x00-\x7F])+$/"
For byte strings with tag TBD110 or TBD112:
"/^(([\x81-\xFF][\x80-\xFF]*)?[\x00-\x7F])*$/"
A tag with tagged content that does not conform to the applicable
regular expression is invalid.
2.2. Preferred Serialization Considerations
For an absolute OID with a prefix of "1.3.6.1.4.1", representations
with both the TBD111 and TBD112 tags are applicable, where the
representation with TBD112 will be five bytes shorter (by leaving out
the prefix h'2b06010401' from the enclosed byte string). This
specification makes that shorter representation the preferred
serialization (see Sections 3.4 and 4.1 of [RFC8949]). Note that
this also implies that the Core Deterministic Encoding Requirements
(Section 4.2.1 of [RFC8949]) require the use of TBD112 tags instead
of TBD111 wherever that is possible.
2.3. Discussion
Staying close to the way object identifiers are encoded in ASN.1 BER
makes back-and-forth translation easy; otherwise we would choose a
more efficient encoding. Object identifiers in IETF protocols are
serialized in dotted decimal form or BER form, so there is an
advantage in not inventing a third form. Also, expectations of the
cost of encoding object identifiers are based on BER; using a
different encoding might not be aligned with these expectations. If
additional information about an OID is desired, lookup services such
as the OID Resolution Service (ORS) [X.672] and the OID Repository
[OID-INFO] are available.
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3. Basic Examples
This section gives simple examples of an absolute and a relative
object identifier, represented via tag number TBD111 and TBD110,
respectively.
RFC editor: These and other examples assume the allocation of 111 for
TBD111 and 110 for TBD110 and need to be changed if that isn't the
actual allocation. Please remove this paragraph.
3.1. Encoding of the SHA-256 OID
ASN.1 Value Notation: { joint-iso-itu-t(2) country(16) us(840)
organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2)
sha256(1) }
Dotted Decimal Notation: 2.16.840.1.101.3.4.2.1
06 # UNIVERSAL TAG 6
09 # 9 bytes, primitive
60 86 48 01 65 03 04 02 01 # X.690 Clause 8.19
# | 840 1 | 3 4 2 1 show component encoding
# 2.16 101
Figure 1: SHA-256 OID in BER
D8 6F # tag(111)
49 # 0b010_01001: mt 2, 9 bytes
60 86 48 01 65 03 04 02 01 # X.690 Clause 8.19
Figure 2: SHA-256 OID in CBOR
3.2. Encoding of a MIB Relative OID
Given some OID (e.g., "lowpanMib", assumed to be "1.3.6.1.2.1.226"
[RFC7388]), to which the following is added:
ASN.1 Value Notation: { lowpanObjects(1) lowpanStats(1)
lowpanOutTransmits(29) }
Dotted Decimal Notation: .1.1.29
0D # UNIVERSAL TAG 13
03 # 3 bytes, primitive
01 01 1D # X.690 Clause 8.20
# 1 1 29 show component encoding
Figure 3: MIB relative object identifier, in BER
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D8 6E # tag(110)
43 # 0b010_00011: mt 2 (bstr), 3 bytes
01 01 1D # X.690 Clause 8.20
Figure 4: MIB relative object identifier, in CBOR
This relative OID saves seven bytes compared to the full OID
encoding.
4. Tag Factoring with Arrays and Maps
The tag content of OID tags can be byte strings (as discussed above),
but also CBOR arrays and maps. The idea in the latter case is that
the tag construct is factored out from each individual item in the
container; the tag is placed on the array or map instead.
When the tag content of an OID tag is an array, this means that the
respective tag is imputed to all elements of the array that are byte
strings, arrays, or maps. (There is no effect on other elements,
including text strings or tags.) For example, when the tag content
of a TBD111 tag is an array, every array element that is a byte
string is an OID, and every element that is an array or map is in
turn treated as discussed here.
When the tag content of an OID tag is a map, this means that a tag
with the same tag number is imputed to all keys in the map that are
byte strings, arrays, or maps; again, there is no effect on keys of
other major types. Note that there is also no effect on the values
in the map.
As a result of these rules, tag factoring in nested arrays and maps
is supported. For example, a 3-dimensional array of OIDs can be
composed by using a single TBD111 tag containing an array of arrays
of arrays of byte strings. All such byte strings are then considered
OIDs.
4.1. Preferred Serialization Considerations
Where tag factoring with tag number TBD111 is used, some OIDs
enclosed in the tag may be encoded in a shorter way by using tag
number TBD112 instead of encoding an unadorned byte string. This
remains the preferred serialization (see also Section 2.2). However,
this specification does not make the presence or absence of tag
factoring a preferred serialization; application protocols can define
where tag factoring is to be used or not (and will need to do so if
they have deterministic encoding requirements).
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4.2. Tag Factoring Example: X.500 Distinguished Name
Consider the X.500 distinguished name:
+==============================+=============+
| Attribute Types | Attribute |
| | Values |
+==============================+=============+
| c (2.5.4.6) | US |
+------------------------------+-------------+
| l (2.5.4.7) | Los Angeles |
| s (2.5.4.8) | CA |
| postalCode (2.5.4.17) | 90013 |
+------------------------------+-------------+
| street (2.5.4.9) | 532 S Olive |
| | St |
+------------------------------+-------------+
| businessCategory (2.5.4.15) | Public Park |
| buildingName | Pershing |
| (0.9.2342.19200300.100.1.48) | Square |
+------------------------------+-------------+
Table 1: Example X.500 Distinguished Name
Table 1 has four "relative distinguished names" (RDNs). The country
(first) and street (third) RDNs are single-valued. The second and
fourth RDNs are multi-valued.
The equivalent representations in CBOR diagnostic notation (Section 8
of [RFC8949]) and CBOR are:
111([{ h'550406': "US" },
{ h'550407': "Los Angeles",
h'550408': "CA",
h'550411': "90013" },
{ h'550409': "532 S Olive St" },
{ h'55040f': "Public Park",
h'0992268993f22c640130': "Pershing Square" }])
Figure 5: Distinguished Name, in CBOR Diagnostic Notation
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d8 6f # tag(111)
84 # array(4)
a1 # map(1)
43 550406 # 2.5.4.6 (4)
62 # text(2)
5553 # "US"
a3 # map(3)
43 550407 # 2.5.4.7 (4)
6b # text(11)
4c6f7320416e67656c6573 # "Los Angeles"
43 550408 # 2.5.4.8 (4)
62 # text(2)
4341 # "CA"
43 550411 # 2.5.4.17 (4)
65 # text(5)
3930303133 # "90013"
a1 # map(1)
43 550409 # 2.5.4.9 (4)
6e # text(14)
3533322053204f6c697665205374 # "532 S Olive St"
a2 # map(2)
43 55040f # 2.5.4.15 (4)
6b # text(11)
5075626c6963205061726b # "Public Park"
4a 0992268993f22c640130 # 0.9.2342.19200300.100.1.48 (11)
6f # text(15)
5065727368696e6720537175617265 # "Pershing Square"
Figure 6: Distinguished Name, in CBOR (109 bytes)
(This example encoding assumes that all attribute values are UTF-8
strings, or can be represented as UTF-8 strings with no loss of
information.)
5. CDDL Control Operators
Concise Data Definition Language (CDDL [RFC8610]) specifications may
want to specify the use of SDNVs or SDNV sequences (as defined for
the tag content for TBD110). This document introduces two new
control operators that can be applied to a target value that is a
byte string:
* ".sdnv", with a control type that contains unsigned integers. The
byte string is specified to be encoded as an [RFC6256] SDNV (BER
encoding) for the matching values of the control type.
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* ".sdnvseq", with a control type that contains arrays of unsigned
integers. The byte string is specified to be encoded as a
sequence of [RFC6256] SDNVs (BER encoding) that decodes to an
array of unsigned integers matching the control type.
* ".oid", like ".sdnvseq", except that the X*40+Y translation for
absolute OIDs is included (see Figure 8).
Figure 7 shows an example for the use of ".sdnvseq" for a part of a
structure using OIDs that could be used in Figure 6; Figure 8 shows
the same with the ".oid" operator.
country-rdn = {country-oid => country-value}
country-oid = bytes .sdnvseq [85, 4, 6]
country-value = text .size 2
Figure 7: Using .sdnvseq
country-rdn = {country-oid => country-value}
country-oid = bytes .oid [2, 5, 4, 6]
country-value = text .size 2
Figure 8: Using .oid
Note that the control type need not be a literal; e.g., "bytes .oid
[2, 5, 4, *uint]" matches all OIDs inside OID arc 2.5.4,
"attributeType".
6. CDDL typenames
For the use with CDDL, the typenames defined in Figure 9 are
recommended:
oid = #6.111(bstr)
roid = #6.110(bstr)
pen = #6.112(bstr)
Figure 9: Recommended typenames for CDDL
7. IANA Considerations
7.1. CBOR Tags
IANA is requested to assign in the 1+1 byte space (24..255) of the
CBOR tags registry [IANA.cbor-tags] the CBOR tag numbers in Table 2,
with the present document as the specification reference.
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+========+================+============================+============+
| Tag | Data Item | Semantics | Reference |
+========+================+============================+============+
| TBD111 | byte string | object identifier (BER | [this |
| | or array or | encoding) | document, |
| | map | | Section 2] |
+--------+----------------+----------------------------+------------+
| TBD110 | byte string | relative object identifier | [this |
| | or array or | (BER encoding); | document, |
| | map | SDNV [RFC6256] sequence | Section 2] |
+--------+----------------+----------------------------+------------+
| TBD112 | byte string | object identifier (BER | [this |
| | or array or | encoding), relative to | document, |
| | map | 1.3.6.1.4.1 | Section 2] |
+--------+----------------+----------------------------+------------+
Table 2: New Tag Numbers
7.2. CDDL Control Operators
IANA is requested to assign in the CDDL Control Operators registry
[IANA.cddl] the CDDL Control Operators in Table 3, with the present
document as the specification reference.
+==========+============================+
| Name | Reference |
+==========+============================+
| .sdnv | [this document, Section 5] |
+----------+----------------------------+
| .sdnvseq | [this document, Section 5] |
+----------+----------------------------+
| .oid | [this document, Section 5] |
+----------+----------------------------+
Table 3: New CDDL Operators
8. Security Considerations
The security considerations of [RFC8949] apply.
The encodings in Clauses 8.19 and 8.20 of [X.690] are quite compact
and unambiguous, but MUST be followed precisely to avoid security
pitfalls. In particular, the requirements set out in Section 2.1 of
this document need to be followed; otherwise, an attacker may be able
to subvert a checking process by submitting alternative
representations that are later taken as the original (or even
something else entirely) by another decoder supposed to be protected
by the checking process.
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OIDs and relative OIDs can always be treated as opaque byte strings.
Actually understanding the structure that was used for generating
them is not necessary, and, except for checking the structure
requirements, it is strongly NOT RECOMMENDED to perform any
processing of this kind (e.g., converting into dotted notation and
back) unless absolutely necessary. If the OIDs are translated into
other representations, the usual security considerations for non-
trivial representation conversions apply; the integer values are
unlimited in range.
An attacker might trick an application into using a byte string
inside a tag-factored data item, where the byte string is not
actually intended to fall under one of the tags defined here. This
may cause the application to emit data with semantics different from
what was intended. Applications therefore need to be restrictive
with respect to what data items they apply tag factoring to.
9. References
9.1. Normative References
[IANA.cbor-tags]
IANA, "Concise Binary Object Representation (CBOR) Tags",
<http://www.iana.org/assignments/cbor-tags>.
[IANA.cddl]
IANA, "Concise Data Definition Language (CDDL)",
<http://www.iana.org/assignments/cddl>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC6256] Eddy, W. and E. Davies, "Using Self-Delimiting Numeric
Values in Protocols", RFC 6256, DOI 10.17487/RFC6256, May
2011, <https://www.rfc-editor.org/info/rfc6256>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/info/rfc8610>.
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[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/info/rfc8949>.
[X.660] International Telecommunications Union, "Information
technology — Procedures for the operation of object
identifier registration authorities: General procedures
and top arcs of the international object identifier tree",
ITU-T Recommendation X.660, July 2011,
<https://www.itu.int/rec/T-REC-X.660>.
[X.680] International Telecommunications Union, "Information
technology — Abstract Syntax Notation One (ASN.1):
Specification of basic notation", ITU-T Recommendation
X.680, August 2015, <https://www.itu.int/rec/T-REC-X.680>.
[X.690] International Telecommunications Union, "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, August 2015, <https://www.itu.int/rec/T-REC-X.690>.
9.2. Informative References
[IANA.enterprise-numbers]
IANA, "Enterprise Numbers",
<http://www.iana.org/assignments/enterprise-numbers>.
[OID-INFO] Orange SA, "OID Repository", 2016,
<http://www.oid-info.com/>.
[PCRE] Ho, A., "PCRE - Perl Compatible Regular Expressions",
2018, <http://www.pcre.org/>.
[RFC7388] Schoenwaelder, J., Sehgal, A., Tsou, T., and C. Zhou,
"Definition of Managed Objects for IPv6 over Low-Power
Wireless Personal Area Networks (6LoWPANs)", RFC 7388,
DOI 10.17487/RFC7388, October 2014,
<https://www.rfc-editor.org/info/rfc7388>.
[X.672] International Telecommunications Union, "Information
technology — Open systems interconnection — Object
identifier resolution system", ITU-T Recommendation X.672,
August 2010, <https://www.itu.int/rec/T-REC-X.672>.
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Appendix A. Change Log
This section is to be removed before publishing as an RFC.
A.1. Changes from -06 to -07
* Various editorial changes prompted by IESG feedback; clarify the
usage of "SDNV" in this document (no leading zeros).
* Add security consideration about tag-factoring.
* Make TBD112, where applicable, the preferred serialization (and
thus the required deterministic encoding) over TBD111.
A.2. Changes from -05 to -06
Add references to specific section numbers of [X.690] to better
explain validity of enclosed byte string.
A.3. Changes from -04 to -05
* Update acknowledgements, contributor list, and author list
A.4. Changes from -03 to -04
Process WGLC and shepherd comments:
* Update references (RFC 8949, URIs for ITU-T)
* Define arc for this document, reference SDN definition
* Restructure, small editorial clarifications
A.5. Changes from -02 to -03
* Add tag TBD112 for PEN-relative OIDs
* Add suggested CDDL typenames; reference RFC8610
A.6. Changes from -01 to -02
Minor editorial changes, remove some remnants, ready for WGLC.
A.7. Changes from -00 to -01
Clean up OID tag factoring.
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A.8. Changes from -07 (bormann) to -00 (ietf)
Resubmitted as WG draft after adoption.
A.9. Changes from -06 to -07
Reduce the draft back to its basic mandate: Describe CBOR tags for
what is colloquially know as ASN.1 Object IDs.
A.10. Changes from -05 to -06
Refreshed the draft to the current date ("keep-alive").
A.11. Changes from -04 to -05
Discussed UUID usage in CBOR, and incorporated fixes proposed by
Olivier Dubuisson, including fixes regarding OID nomenclature.
A.12. Changes from -03 to -04
Changes occurred based on limited feedback, mainly centered around
the abstract and introduction, rather than substantive technical
changes. These changes include:
* Changed the title so that it is about tags and techniques.
* Rewrote the abstract to describe the content more accurately, and
to point out that no changes to the wire protocol are being
proposed.
* Removed "ASN.1" from "object identifiers", as OIDs are independent
of ASN.1.
* Rewrote the introduction to be more about the present text.
* Proposed a concise OID arc.
* Provided binary regular expression forms for OID validation.
* Updated IANA registration tables.
A.13. Changes from -02 to -03
Many significant changes occurred in this version. These changes
include:
* Expanded the draft scope to be a comprehensive CBOR update.
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* Added OID-related sections: OID Enumerations, OID Maps and Arrays,
and Applications and Examples of OIDs.
* Added Tag 36 update (binary MIME, better definitions).
* Added stub/experimental sections for X.690 Series Tags (tag <<X>>)
and Regular Expressions (tag 35).
* Added technique for representing sets and multisets.
* Added references and fixed typos.
Acknowledgments
Sean Leonard started the work on this document in 2014 with an
elaborate proposal. Jim Schaad provided a significant review of this
document. Rob Wilton's IESG review prompted us to provide preferred
serialization considerations.
Contributors
Sean Leonard
Penango, Inc.
5900 Wilshire Boulevard
21st Floor
Los Angeles, CA, 90036
United States of America
Email: dev+ietf@seantek.com
Author's Address
Carsten Bormann
Universität Bremen TZI
Postfach 330440
D-28359 Bremen
Germany
Phone: +49-421-218-63921
Email: cabo@tzi.org
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