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.694 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、ASN.1 encoding rules: Mapping W3C XML schema definitions into ASN.1 Recommendation ITU-T X.694 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.8
3、9 Network 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
4、 X.240X.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.49
5、9 DIRECTORY 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 Ma
6、nagement 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
7、 Generic 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
8、CLOUD COMPUTING SECURITY X.1600X.1699 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T X.694 (08/2015) i INTERNATIONAL STANDARD ISO/IEC 8825-5 RECOMMENDATION ITU-T X.694 Information technology ASN.1 encoding rules: Mapping W3C XML schema definitions into ASN.1 Summa
9、ry Recommendation ITU-T X.694 | ISO/IEC 8825-5 defines rules for mapping an XSD Schema (a schema conforming to the W3C XML Schema specification) to an ASN.1 schema in order to use ASN.1 encoding rules such as the Basic Encoding Rules (BER), the Distinguished Encoding Rules (DER), the Packed Encoding
10、 Rules (PER) or the XML Encoding Rules (XER) for the transfer of information defined by the XSD Schema. The use of this Recommendation | International Standard with the ASN.1 Extended XML Encoding Rules (EXTENDED-XER) provides the same XML representation of values as that defined by the original XSD
11、 Schema, but also provides the ability to encode the specified XML with an efficient binary representation (binary XML). An XML document can be converted to binary XML (for storage or transfer) using the ASN.1 generated by this mapping, and the resulting binary can be converted back to the same XML
12、document for further XML processing. Two versions of the mapping are defined. Version 1 of the mapping was published in 2004, and a Corrigendum was subsequently issued renaming the types DATE-TIME and DURATION in Annex A (in order to avoid conflict with the DATE-TIME and DURATION types defined in Re
13、c. ITU-T X.680 | ISO/IEC 8824-1). The Version 2 mapping is more efficient in two areas: the ASN.1 time types are used rather than VisibleString for mappings of dates and times; the FastInfoset specification (Rec. ITU-T X.891 | ISO/IEC 24824-1) is used for the mapping of XSD wild-cards. Both these ch
14、anges to the mapping provide much more compact binary encodings for the XML specified by the XSD. NOTE The specification of the Version 1 mapping (with applicable corrections) will be maintained in the next edition of this Recommendation | International Standard, but it is expected that subsequent e
15、ditions will document only the Version 2 mapping. Application of the ASN.1 extended XML Encoding Rules to both versions of the mapping will produce the same XML (which is the same as that specified by the XSD). However, application of other ASN.1 encoding rules to the Version 1 mapping results in a
16、verbose character-based encoding of date and time types and of XSD wild-cards, whilst application of the Version 2 mapping results in a more compact binary encoding using ASN.1 time types and the FastInfoset specification. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T X.69
17、4 2004-01-13 17 11.1002/1000/7106 1.1 ITU-T X.694 (2004) Technical Cor. 1 2005-11-29 17 11.1002/1000/8639 1.2 ITU-T X.694 (2004) Amd. 1 2007-05-29 17 11.1002/1000/9111 2.0 ITU-T X.694 2008-11-13 17 11.1002/1000/9612 2.1 ITU-T X.694 (2008) Cor. 1 2011-10-14 17 11.1002/1000/11382 2.2 ITU-T X.694 (2008
18、) Cor. 2 2014-03-01 17 11.1002/1000/12149 3.0 ITU-T X.694 2015-08-13 17 11.1002/1000/12486 _ * To access the Recommendation, type the URL http:/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
19、. ii Rec. ITU-T X.694 (08/2015) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of IT
20、U. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics f
21、or study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered 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
22、 on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may co
23、ntain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when 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 expre
24、ss requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Proper
25、ty Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted 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 i
26、ntellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that 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
27、 rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T X.694 (08/2015) iii CONTENTS Page 1 Scope 1 2 Normative references 1 2.1 Identical Recommendations | International Standards 1 2.2 Additional references 2
28、 3 Definitions 2 3.1 Imported definitions 2 3.2 Additional definitions 3 4 Abbreviations . 3 5 Notation 3 6 Purpose and extent of standardization 3 7 Mapping XSD Schemas . 4 8 Ignored schema components and properties . 5 9 ASN.1 modules 6 10 Name conversion 6 10.1 General 6 10.2 Generating ASN.1 typ
29、e definitions that are references to ASN.1 type assignments . 7 10.3 Generating identifiers and type reference names 7 10.4 Order of the mapping 9 11 Mapping uses of XSD built-in types 10 12 Mapping facets. 10 12.1 The length, minLength, and maxLength facets 11 12.2 The pattern facet . 11 12.3 The w
30、hiteSpace facet. 11 12.4 The enumeration facet . 12 12.5 Other facets . 14 13 Mapping simple type definitions . 14 14 Mapping element declarations . 16 15 Mapping attribute declarations . 17 16 Mapping values of simple type definitions . 17 17 Mapping model group definitions . 17 18 Mapping model gr
31、oups . 17 19 Mapping particles 18 20 Mapping complex type definitions 19 21 Mapping wildcards . 20 22 Mapping attribute uses 22 23 Mapping uses of simple and complex type definitions (general case) . 22 24 Mapping special uses of simple and complex type definitions (substitutable) . 23 25 Mapping sp
32、ecial uses of simple and complex type definitions (substitutable, nillable) . 24 26 Mapping special uses of simple type definitions (nillable) . 25 27 Mapping special uses of complex type definitions (nillable) 26 28 Mapping special uses of element declarations (head of element substitution group) 2
33、7 29 Generating special ASN.1 type assignments for types used in element declarations 27 30 Generating special ASN.1 type assignments for types belonging to a derivation hierarchy 29 31 Generating special ASN.1 type assignments for element substitution groups 29 Annex A ASN.1 type definitions corres
34、ponding to XSD built-in types for the Version 1 mapping 30 Annex B ASN.1 type definitions corresponding to XSD built-in types for the Version 2 mapping. 34 iv Rec. ITU-T X.694 (08/2015) Page Annex C Identification of the XSD module 38 Annex D Examples of mappings 39 D.1 A Schema using simple type de
35、finitions 39 D.2 The corresponding ASN.1 definitions . 40 D.3 Further examples . 41 Annex E Use of the mapping to provide binary encodings for W3C XML Schema 61 E.1 Encoding XSD Schemas . 61 E.2 Transfer without using the XSD Schema for Schemas . 61 E.3 Transfer using the XSD Schema for Schemas 61 R
36、ec. ITU-T X.694 (08/2015) v Introduction This Recommendation | International Standard specifies Version 1 and Version 2 of a mapping from a W3C XML Schema definition (an XSD Schema) into an ASN.1 schema. The mappings can be applied to any XSD Schema. Both mappings specify the generation of one or mo
37、re ASN.1 modules containing type definitions, together with ASN.1 XER encoding instructions. These are jointly described as an ASN.1 schema for XML documents. This ASN.1 schema (produced by either Version of the mapping), when used with the ASN.1 Extended XML Encoding Rules (EXTENDED-XER), can be us
38、ed to generate and to validate the same set of W3C XML 1.0 documents as the original XSD Schema. The resulting ASN.1 types and encodings support the same semantic content as the XSD Schema. Thus ASN.1 tools can be used interchangeably with XSD tools for the generation and processing of the specified
39、 XML documents. Other standardized ASN.1 encoding rules, such as the Distinguished Encoding Rules (DER) or the Packed Encoding Rules (PER), can be used in conjunction with this standardized mapping, but produce encodings for Version 2 of the mapping that differ from (and are less verbose than) those
40、 produced by Version 1 for XSD constructs involving dates and times or wildcards. The combination of this Recommendation | International Standard with ASN.1 Encoding Rules provides fully-standardized and vendor-independent compact and canonical binary encodings for data originally defined using an X
41、SD Schema. The ASN.1 schema provides a clear separation between the specification of the information content of messages (their abstract syntax) and the precise form of the XML document (for example, use of attributes instead of elements). This results in both a clearer and generally a less verbose
42、schema than the original XSD Schema. Annex A forms an integral part of this Recommendation | International Standard, and is an ASN.1 module containing a set of ASN.1 type assignments that correspond to each of the XSD built-in types for Version 1 of the mapping. Mappings of XSD Schemas into ASN.1 sc
43、hemas either import the type reference names of those type assignments or include the type definitions in-line. Annex B also forms an integral part of this Recommendation | International Standard and provides the ASN.1 module for Version 2 of the mapping. Annex C does not form an integral part of th
44、is Recommendation | International Standard, and summarizes the object identifier, OID internationalized resource identifier and object descriptor values assigned in this Recommendation | International Standard.Annex D does not form an integral part of this Recommendation | International Standard, an
45、d gives examples of the mapping of XSD Schemas into ASN.1 schemas. Annex E does not form an integral part of this Recommendation | International Standard, and describes the use of the mapping defined in this Recommendation | International Standard, in conjunction with standardized ASN.1 Encoding Rul
46、es, to provide compact and canonical encodings for data defined using an XSD Schema. ISO/IEC 8825-5:2015 (E) Rec. ITU-T X.694 (08/2015) 1 INTERNATIONAL STANDARD ITU-T RECOMMENDATION Information technology ASN.1 encoding rules: Mapping W3C XML schema definitions into ASN.1 1 Scope This Recommendation
47、 | International Standard specifies two Versions of a mapping from any XSD Schema into an ASN.1 schema. The ASN.1 schema for both Versions support the same semantics and validate the same set of XML documents. This Recommendation | International Standard specifies the final XER encoding instructions
48、 that are to be applied as part of the defined mapping to ASN.1 types, but does not specify which syntactic form is to be used for the specification of those final XER encoding instructions, or the order or manner of their assignment. NOTE Implementers of tools generating these mappings may choose a
49、ny syntactic form or order of assignment that results in the specified final XER encoding instructions being applied. Examples in this Recommendation | International Standard generally use the type prefix form, but use of an XER Encoding Control Section may be preferred for the mapping of a complete XSD Schema, as a matter of style. There are different ways (syntactically) of assigning XER encoding instructions for use in EXTENDED-XER encodings (for example, use of ASN.1 type p
