1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T X.682 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (08/2015) SERIES X: DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY OSI networking and system aspects Abstract Syntax Notation One (ASN.1) Information technology
2、Abstract Syntax Notation One (ASN.1): Constraint specification Recommendation ITU-T X.682 ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY PUBLIC DATA NETWORKS Services and facilities X.1X.19 Interfaces X.20X.49 Transmission, signalling and switching X.50X.89 Net
3、work aspects X.90X.149 Maintenance X.150X.179 Administrative arrangements X.180X.199 OPEN SYSTEMS INTERCONNECTION Model and notation X.200X.209 Service definitions X.210X.219 Connection-mode protocol specifications X.220X.229 Connectionless-mode protocol specifications X.230X.239 PICS proformas X.24
4、0X.259 Protocol Identification X.260X.269 Security Protocols X.270X.279 Layer Managed Objects X.280X.289 Conformance testing X.290X.299 INTERWORKING BETWEEN NETWORKS General X.300X.349 Satellite data transmission systems X.350X.369 IP-based networks X.370X.379 MESSAGE HANDLING SYSTEMS X.400X.499 DIR
5、ECTORY X.500X.599 OSI NETWORKING AND SYSTEM ASPECTS Networking X.600X.629 Efficiency X.630X.639 Quality of service X.640X.649 Naming, Addressing and Registration X.650X.679 Abstract Syntax Notation One (ASN.1) X.680X.699 OSI MANAGEMENT Systems management framework and architecture X.700X.709 Managem
6、ent communication service and protocol X.710X.719 Structure of management information X.720X.729 Management functions and ODMA functions X.730X.799 SECURITY X.800X.849 OSI APPLICATIONS Commitment, concurrency and recovery X.850X.859 Transaction processing X.860X.879 Remote operations X.880X.889 Gene
7、ric applications of ASN.1 X.890X.899 OPEN DISTRIBUTED PROCESSING X.900X.999 INFORMATION AND NETWORK SECURITY X.1000X.1099 SECURE APPLICATIONS AND SERVICES X.1100X.1199 CYBERSPACE SECURITY X.1200X.1299 SECURE APPLICATIONS AND SERVICES X.1300X.1399 CYBERSECURITY INFORMATION EXCHANGE X.1500X.1599 CLOUD
8、 COMPUTING SECURITY X.1600X.1699 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T X.682 (08/2015) i INTERNATIONAL STANDARD ISO/IEC 8824-3 RECOMMENDATION ITU-T X.682 Information technology Abstract Syntax Notation One (ASN.1): Constraint specification Summary Recomme
9、ndation ITU-T X.682 | ISO/IEC 8824-3 provides the ASN.1 notation for the general case of constraint and exception specification by which the data values of a structured data type can be limited. The notation also provides for signalling if and when a constraint is violated. History Edition Recommend
10、ation Approval Study Group Unique ID* 1.0 ITU-T X.682 1994-07-01 7 11.1002/1000/3044 2.0 ITU-T X.682 1997-12-12 7 11.1002/1000/4445 2.1 ITU-T X.682 (1997) Technical Cor. 1 2000-03-31 7 11.1002/1000/5047 2.2 ITU-T X.682 (1997) Technical Cor. 2 2001-02-02 7 11.1002/1000/5334 2.3 ITU-T X.682 (1997) Tec
11、hnical Cor. 3 2001-03-15 7 11.1002/1000/5434 3.0 ITU-T X.682 2002-07-14 17 11.1002/1000/6087 4.0 ITU-T X.682 2008-11-13 17 11.1002/1000/9606 4.1 ITU-T X.682 (2008) Cor. 1 2014-03-01 17 11.1002/1000/12145 5.0 ITU-T X.682 2015-08-13 17 11.1002/1000/12481 * To access the Recommendation, type the URL ht
12、tp:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T X.682 (08/2015) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the fie
13、ld of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardiz
14、ing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered
15、 by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate
16、 both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved w
17、hen all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPE
18、RTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted
19、 by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that
20、 this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec.
21、ITU-T X.682 (08/2015) iii CONTENTS Page Introduction . iv Information technology Abstract Syntax Notation One (ASN.1): Constraint specification . 1 1 Scope 1 2 Normative references 1 2.1 Identical Recommendations | International Standards . 1 3 Definitions 1 3.1 Specification of basic notation 1 3.2
22、 Information object specification 1 3.3 Parameterization of ASN.1 specification 1 3.4 Additional definitions 1 4 Abbreviations . 2 5 Convention . 2 6 Notation 2 6.1 Constraint 2 7 ASN.1 lexical items 2 7.1 Additional keywords . 2 8 General constraint specification . 2 9 User-defined constraints . 3
23、10 Table constraints, including component relation constraints 4 11 Contents constraints 7 Annex A Constraining instance-of types . 8 A.4 Example 8 Annex B Summary of the notation . 9 iv Rec. ITU-T X.682 (08/2015) Introduction Application designers require a notation to define a structured data type
24、 to convey their semantics. This is provided in Rec. ITU-T X.680 | ISO/IEC 8824-1 and Rec. ITU-T X.681 | ISO/IEC 8824-2. A notation is also required to further constrain the values that can appear. Examples of such constraints are restricting the range of some component(s), or using a specified info
25、rmation object set to constrain an “ObjectClassFieldType“ component, or using the “AtNotation“ to specify a relation between components. This Recommendation | International Standard provides the notation for the general case of constraint specification. NOTE 1 For historical reasons the special case
26、 of a “subtype constraint“ is specified in Rec. ITU-T X.680 | ISO/IEC 8824-1. Constraint notation can appear (in round brackets) after any use of the syntactic construct “Type“, and the purpose of this Recommendation | International Standard is to specify the general case of what goes in the round b
27、rackets. NOTE 2 Multiple constraints (each inside its own round brackets) can be applied to the same “Type“, as the result of constraining a “Type“ is itself formally a “Type“ construct. When a constraint is applied to the textually outermost use of a “Type“ construct, it results in the creation of
28、a new type which is a subtype of the original (parent) type. A subtype of a parent type can itself be used in defining other subtypes of the same parent type in other uses of the constraint notation. Thus the subset of values constituting a subtype can be defined either by limiting the range of the
29、parent type, or by specifying the subtype as a union of sets of values. NOTE 3 The “ValueSet“ notation specified in Rec. ITU-T X.680 | ISO/IEC 8824-1, 16.7, provides a further means of specifying a subtype. Constraints may also be used to produce a subtype of a parent type (as described above) when
30、the notation is embedded within another type. However, some “component relation“ constraints are textually included following a “Type“ (within a set or sequence type definition), but are not used to restrict the set of possible values of the “Type“ which they follow (the referencing component). Rath
31、er, they specify a relation between the value of the referencing component and the value of one or more other “Type“s in the same set or sequence type (called the referenced components). Component relation constraints can be seen as subtyping the sequence type within which they are embedded, but not
32、 necessarily the referencing type. A constraint on an “ObjectClassFieldType“ component can be applied by restricting the type or values in the component by using an information object set. Such constraints are called table constraints, since they are specified in terms of the “associated table“ of t
33、he object set. The component relation constraints defined in this Recommendation | International Standard are a special case of table constraints. Finally, a “Type“ may be subtyped by specifying the set of values in the subtype by human-readable text. Such a constraint is called a user-defined const
34、raint. For example, a user-defined constraint can be specified to constrain a BIT STRING to the set of values produced by the encryption of a value of a specified ASN.1 type. It is the purpose of this Recommendation | International Standard to provide the notation to be used for specifying table con
35、straints (including component relation constraints), and user-defined constraints. NOTE 4 In general, full support for the specification of constraints in a flexible way (particularly component relation constraints, subtyping constraints, and user-defined constraints with a formally defined body) wo
36、uld require notation with a power comparable to that of programming languages. Such power can only be sensibly provided by the establishment of links from the ASN.1 notation into some other defined computer language. This version of this Recommendation | International Standard does not provide such
37、links, and hence supports only a small number of constraining mechanisms. While the embedding of notation defining constraints (subtypes and relationships) will frequently be the most convenient form of specification (particularly for the simple subtyping of primitive components of structures), sepa
38、rate (external) specification will sometimes be preferred, particularly where the constraints are being imposed by a separate group from that which defined the basic protocol. NOTE 5 The parameterization defined in Rec. ITU-T X.683 | ISO/IEC 8824-4 is specifically designed to enable a piece of ASN.1
39、 specification (and in particular, a constraint) to be parameterized, allowing the actual constraint to be imposed by some other group that provides actual parameters for the parameterized construct. Rec. ITU-T X.682 (08/2015) v The notations for constraint specification supported here are: user-def
40、ined constraints (see clause 9); table constraints, including component relation constraints between two components which are carrying values related to an information object, defined using the notation of Rec. ITU-T X.681 | ISO/IEC 8824-2 (see clause 10); contents constraints (see clause 11). The a
41、pplication of table constraints to the “InstanceOfType“ construct of Rec. ITU-T X.681 | ISO/IEC 8824-2, Annex C, is specified in Annex A. ISO/IEC 8824-3:2005 (E) Rec. ITU-T X.682 (08/2015) 1 INTERNATIONAL STANDARD ITU-T RECOMMENDATION Information technology Abstract Syntax Notation One (ASN.1): Cons
42、traint specification 1 Scope This Recommendation | International Standard is part of Abstract Syntax Notation One (ASN.1) and provides notation for specifying user-defined constraints, table constraints, and contents constraints. 2 Normative references The following Recommendations and International
43、 Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on thi
44、s Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization B
45、ureau of the ITU maintains a list of currently valid ITU-T Recommendations. 2.1 Identical Recommendations | International Standards Recommendation ITU-T X.680 (2015) | ISO/IEC 8824-1:2015, Information technology Abstract Syntax Notation One (ASN.1): Specification of basic notation. Recommendation IT
46、U-T X.681 (2015) | ISO/IEC 8824-2:2015, Information technology Abstract Syntax Notation One (ASN.1): Information object specification. Recommendation ITU-T X.683 (2015) | ISO/IEC 8824-4:2015, Information technology Abstract Syntax Notation One (ASN.1): Parameterization of ASN.1 specifications. 3 Def
47、initions For the purposes of this Recommendation | International Standard, the following definitions apply. 3.1 Specification of basic notation This Recommendation | International Standard uses the terms defined in Rec. ITU-T X.680 | ISO/IEC 8824-1. 3.2 Information object specification This Recommen
48、dation | International Standard uses the terms defined in Rec. ITU-T X.681 | ISO/IEC 8824-2. 3.3 Parameterization of ASN.1 specification This Recommendation | International Standard uses the following term defined in Rec. ITU-T X.683 | ISO/IEC 8824-4: parameterized type. 3.4 Additional definitions 3
49、.4.1 component relation constraint: A constraint on the values of a set type or sequence type which is textually associated with one of the component types (the referencing component) of the set type or sequence type, and which specifies the relationship between the value of that component and the values of one or more other components (the referenced components). ISO/IEC 8824-3:2005 (E) 2 Rec. ITU-T X.682 (08/2015) 3.4.2 constrained type: The innermost “Type“ which contains the referenci
