c069980_ISO_IEC_8825-6_2015.pdf

Reference number ISO/IEC 8825-62015E ISO/IEC 2015 INTERNATIONAL STANDARD ISO/IEC 8825-6 Third edition 2015-11-15 Ination technology ASN.1 encoding rules Registration and application of PER encoding instructions Technologies de lination Rgles de codage ASN.1 Enregistrement et application des instructions de codage PER ISO/IEC 8825-62015E COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2015 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. 41 22 749 01 11 Fax 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2015 – All rights reserved ISO/IEC 8825-62015E ISO/IEC 2015 – All rights reserved iii Foreword ISO the International Organization for Standardization and IEC the International Electrotechnical Commission the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of ination technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. This third edition cancels and replaces the second edition of ISO/IEC 8825-62008 which has been technically revised. ISO/IEC 8825-6 was prepared by Joint Technical Committee ISO/IEC JTC 1, Ination technology, Subcommittee SC 6, Telecommunications and ination exchange between systems, in collaboration with ITU-T. The identical text is published as ITU-T X.695 08/2015. 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.695 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 Ination technology – ASN.1 encoding rules Registration and application of PER encoding instructions Recommendation ITU-T X.695 ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY PUBLIC DATA NETWORKS Services and facilities X.1–X.19 Interfaces X.20–X.49 Transmission, signalling and switching X.50–X.89 Network aspects X.90–X.149 Maintenance X.150–X.179 Administrative arrangements X.180–X.199 OPEN SYSTEMS INTERCONNECTION Model and notation X.200–X.209 Service definitions X.210–X.219 Connection-mode protocol specifications X.220–X.229 Connectionless-mode protocol specifications X.230–X.239 PICS proas X.240–X.259 Protocol Identification X.260–X.269 Security Protocols X.270–X.279 Layer Managed Objects X.280–X.289 Conance testing X.290–X.299 INTERWORKING BETWEEN NETWORKS General X.300–X.349 Satellite data transmission systems X.350–X.369 IP-based networks X.370–X.379 MESSAGE HANDLING SYSTEMS X.400–X.499 DIRECTORY X.500–X.599 OSI NETWORKING AND SYSTEM ASPECTS Networking X.600–X.629 Efficiency X.630–X.639 Quality of service X.640–X.649 Naming, Addressing and Registration X.650–X.679 Abstract Syntax Notation One ASN.1 X.680–X.699 OSI MANAGEMENT Systems management framework and architecture X.700–X.709 Management communication service and protocol X.710–X.719 Structure of management ination X.720–X.729 Management functions and ODMA functions X.730–X.799 SECURITY X.800–X.849 OSI APPLICATIONS Commitment, concurrency and recovery X.850–X.859 Transaction processing X.860–X.879 Remote operations X.880–X.889 Generic applications of ASN.1 X.890–X.899 OPEN DISTRIBUTED PROCESSING X.900–X.999 INATION AND NETWORK SECURITY X.1000–X.1099 SECURE APPLICATIONS AND SERVICES X.1100–X.1199 CYBERSPACE SECURITY X.1200–X.1299 SECURE APPLICATIONS AND SERVICES X.1300–X.1399 CYBERSECURITY INATION EXCHANGE X.1500–X.1599 CLOUD COMPUTING SECURITY X.1600–X.1699 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T X.695 08/2015 i INTERNATIONAL STANDARD ISO/IEC 8825-6 RECOMMENDATION ITU-T X.695 Ination technology – ASN.1 encoding rules Registration and application of PER encoding instructions Summary Recommendation ITU-T X.695 | ISO/IEC 8825-6 specifies the rules for applying PER encoding instructions using either type prefixes or an encoding control section. Encoding instructions are a means of modifying the encodings of ASN.1 types for some specified encoding rule in this case PER. They can be inserted in an ASN.1 specification in square brackets much like a tag in the Basic Encoding Rules, BER immediately before the type that they affect type prefixes, or they can be collected together at the end of an ASN.1 module an encoding control section. It also specifies the procedures for developing, registering and publishing new PER encoding instructions from time to time. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T X.695 2007-05-29 17 11.1002/1000/9112 2.0 ITU-T X.695 2008-11-13 17 11.1002/1000/9613 3.0 ITU-T X.695 2015-08-13 17 11.1002/1000/12488 ____________________ * 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. ii Rec. ITU-T X.695 08/2015 FOREWORD The International Telecommunication Union ITU is the United Nations specialized agency in the field of telecommunications, ination 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 standardizing 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 by the procedure laid down in WTSA Resolution 1. In some areas of ination 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 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 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 express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU 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 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 this may not represent the latest ination 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. ITU-T X.695 08/2015 iii CONTENTS Page 1 Scope ...................................................................................................................................................................... 1 2 Normative references.............................................................................................................................................. 1 2.1 Identical Recommendations | International Standards ................................................................................ 1 3 Definitions .............................................................................................................................................................. 1 4 Abbreviations ......................................................................................................................................................... 2 5 Notation .................................................................................................................................................................. 2 6 Ination to be provided to specify a PER encoding instruction ........................................................................ 2 7 Status of a PER EI proposal during the approval process ...................................................................................... 3 8 Approval process .................................................................................................................................................... 3 9 Publication by the Registration Authority .............................................................................................................. 4 10 Restrictions on the use of PER Encoding Instructions ........................................................................................... 4 11 Assigning a PER EI to an ASN.1 type using a type prefix ..................................................................................... 4 12 Assigning a PER encoding instruction using an encoding control section ............................................................. 5 12.1 The encoding instruction assignment list .................................................................................................... 5 12.2 Identification of the targets for a PER encoding instruction using a target list ........................................... 5 12.2.1 General rules ................................................................................................................................. 5 12.2.2 Target identification using an ASN.1 type reference and identifiers ............................................ 7 12.2.3 Target identification using a built-in type name ............................................................................ 8 12.2.4 Use of identifiers in context .......................................................................................................... 8 13 Multiple assignment of PER encoding instructions ................................................................................................ 9 13.1 Order in which multiple assignments are considered .................................................................................. 9 13.2 Effect of assigning a negating encoding instruction .................................................................................... 9 13.3 Multiple assignment of PER encoding instructions .................................................................................... 9 Annex A − Example of the application of PER EIs using prefixed encoding instructions ...............................................11 Annex B − Example of the application of PER EIs using targeted encoding instructions ...............................................14 Annex C − Summary of the ASN.1 notation ....................................................................................................................16 iv Rec. ITU-T X.695 08/2015 Introduction Rec. ITU-T X.680 | ISO/IEC 8824-1 makes syntactic provision for the application of encoding instructions to modify the behaviour of a particular set of encoding rules, identified by an encoding reference see Rec. ITU-T X.680 | ISO/IEC 8824-1. Rec. ITU-T X.691 | ISO/IEC 8825-2 specifies the BASIC-PER and CANONICAL-PER encoding rules, each with two variants the ALIGNED variant and the UNALIGNED variant. The PER encoding instructions allow minor variations to be made in parts of the UNALIGNED variant of a BASIC-PER and CANONICAL-PER encoding. They have no effect on the ALIGNED variant of these encodings. NOTE – The purpose of PER encoding instructions is to ease the task of producing an ASN.1 specification, which when encoded by the UNALIGNED variant of a PER encoding produces bit-patterns that exactly match those of a legacy protocol. It is unusual for the ALIGNED variant to be used for this purpose, and so for simplicity all PER encoding instructions have no effect on the ALIGNED variant. This Recommendation | International Standard specifies the use of type prefixes and encoding control sections see Rec. ITU-T X.680 | ISO/IEC 8824-1, 31.3 and clause 54 to associate one or more PER encoding instructions with an ASN.1 type. Where an encoding instruction is associated with an ASN.1 type, specific clauses in Rec. ITU-T X.691 | ISO/IEC 8825-2 are amended according to the specification of the encoding instruction. These mechanisms are similar to those for the application of XER encoding instructions specified in Rec. ITU-T X.693 | ISO/IEC 8825-4. This Recommendation | International Standard also specifies the procedures for the operation of a Registration Authority to receive, record and publish the specification of PER encoding instructions that are agreed from time to time. The Registration Authority is the ITU Telecommunication Standardizat