1、 Reference number ISO/IEC 8825-2:2015(E) ISO/IEC 2015INTERNATIONAL STANDARD ISO/IEC 8825-2 Fifth edition 2015-11-15 Information technology ASN.1 encoding rules: Specification of Packed Encoding Rules (PER) Technologies de linformation Rgles de codage ASN.1: Spcification des rgles de codage compact (
2、PER) ISO/IEC 8825-2:2015(E) 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 form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an i
3、ntranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs 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
4、 Published in Switzerland ii ISO/IEC 2015 All rights reservedISO/IEC 8825-2:2015(E) ISO/IEC 2015 All rights reserved iiiForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization.
5、 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 int
6、erest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance wit
7、h 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 req
8、uires 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 fifth edition can
9、cels and replaces the fourth edition of ISO/IEC 8825-2:2008 which has been technically revised. It also incorporates ISO/IEC 8825-2:2008/Cor.1:2012, ISO/IEC 8825-5:2008.Cor.2:2012, ISO/IEC 8825-2:2008/Cor.3:2015 and ISO/IEC 8825-2:2008/Cor.4:2015. ISO/IEC 8825-1 was prepared by Joint Technical Commi
10、ttee ISO/IEC JTC 1, Information technology, Subcommittee SC 6, Telecommunications and information exchange between systems, in collaboration with ITU-T. The identical text is published as ITU-T X.691 (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.691 TELECOM
11、MUNICATION 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 ASN.1 encoding rules: Specification of Packed Encoding Rules (PER) Recommendation ITU-T X.
12、691 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 Network aspects X.90X.149 Maintenance X.150X.179 Administrative arrangements X.180X.199 O
13、PEN 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.240X.259 Protocol Identification X.260X.269 Security Protocols X.270X.279 Layer Managed
14、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 DIRECTORY X.500X.599 OSI NETWORKING AND SYSTEM ASPECTS Networking X.600X.629 Efficiency X
15、.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 Management communication service and protocol X.710X.719 Structure of management information
16、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 Generic applications of ASN.1 X.890X.899 OPEN DISTRIBUTED PROCESSING X.900X.999 INFORMATIO
17、N 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 COMPUTING SECURITY X.1600X.1699 For further details, please refer to the list of ITU-
18、T Recommendations. Rec. ITU-T X.691 (08/2015) i INTERNATIONAL STANDARD ISO/IEC 8825-2 RECOMMENDATION ITU-T X.691 Information technology ASN.1 encoding rules: Specification of Packed Encoding Rules (PER) Summary Recommendation ITU-T X.691 | ISO/IEC 8825-2 describes a set of encoding rules that can be
19、 applied to values of all ASN.1 types to achieve a much more compact representation than that achieved by the Basic Encoding Rules and its derivatives (described in Rec. ITU-T X.690 | ISO/IEC 8825-1). History Edition Recommendation Approval Study Group Unique ID *1.0 ITU-T X.691 1995-04-10 7 11.1002
20、/1000/3047 1.1 ITU-T X.691 (1995) Technical Cor. 1 1997-12-12 7 11.1002/1000/4184 1.2 ITU-T X.691 (1995) Technical Cor. 2 1997-12-12 7 11.1002/1000/4185 2.0 ITU-T X.691 1997-12-12 7 11.1002/1000/4448 2.1 ITU-T X.691 (1997) Technical Cor. 1 1999-06-18 7 11.1002/1000/4707 2.2 ITU-T X.691 (1997) Amd. 1
21、 1999-06-18 7 11.1002/1000/4706 2.3 ITU-T X.691 (1997) Technical Cor. 2 2001-02-02 7 11.1002/1000/5337 2.4 ITU-T X.691 (1997) Technical Cor. 3 2001-03-15 7 11.1002/1000/5338 3.0 ITU-T X.691 2002-07-14 17 11.1002/1000/6090 3.1 ITU-T X.691 (2002) Amd. 1 2003-10-29 17 11.1002/1000/7022 3.2 ITU-T X.691
22、(2002) Technical Cor. 1 2005-05-14 17 11.1002/1000/8513 3.3 ITU-T X.691 (2002) Technical Cor. 2 2005-11-29 17 11.1002/1000/8638 3.4 ITU-T X.691 (2002) Amd. 2 2006-06-13 17 11.1002/1000/8839 3.5 ITU-T X.691 (2002) Amd. 3 2007-05-29 17 11.1002/1000/9109 4.0 ITU-T X.691 2008-11-13 17 11.1002/1000/9609
23、4.1 ITU-T X.691 (2008) Cor. 1 2011-10-14 17 11.1002/1000/11379 4.2 ITU-T X.691 (2008) Cor. 2 2012-04-13 17 11.1002/1000/11585 4.3 ITU-T X.691 (2008) Cor. 3 2014-11-13 17 11.1002/1000/12337 4.4 ITU-T X.691 (2008) Cor. 4 2014-11-13 17 11.1002/1000/12339 5.0 ITU-T X.691 2015-08-13 17 11.1002/1000/12484
24、 *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.691 (08/2015) FOREWORD The International Telecommunication Union (ITU) is t
25、he 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 ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Re
26、commendations 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. T
27、he 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 on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Admi
28、nistration“ 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 c
29、ompliance 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 Recommendati
30、on 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 claime
31、d 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 Recommen
32、dation. 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 rights reserved. No part of this publication may be reproduced, by any means whatsoever, wi
33、thout the prior written permission of ITU. Rec. ITU-T X.691 (08/2015) iii CONTENTS Page Introduction . vi 1 Scope 1 2 Normative references 1 2.1 Identical Recommendations | International Standards . 1 2.2 Additional references 1 3 Definitions 2 3.1 Specification of Basic Notation . 2 3.2 Information
34、 Object Specification 2 3.3 Constraint Specification 2 3.4 Parameterization of ASN.1 Specification 2 3.5 Basic Encoding Rules 2 3.6 PER Encoding Instructions . 2 3.7 Additional definitions 2 4 Abbreviations . 5 5 Notation 5 6 Convention . 5 7 Encoding rules defined in this Recommendation | Internati
35、onal Standard 5 8 Conformance 6 9 PER encoding instructions 6 10 The approach to encoding used for PER 7 10.1 Use of the type notation. 7 10.2 Use of tags to provide a canonical order . 7 10.3 PER-visible constraints . 7 10.4 Type and value model used for encoding 9 10.5 Structure of an encoding 9 1
36、0.6 Types to be encoded 10 11 Encoding procedures 10 11.1 Production of the complete encoding 10 11.2 Open type fields 11 11.3 Encoding as a non-negative-binary-integer . 11 11.4 Encoding as a 2s-complement-binary-integer . 12 11.5 Encoding of a constrained whole number . 12 11.6 Encoding of a norma
37、lly small non-negative whole number . 13 11.7 Encoding of a semi-constrained whole number . 13 11.8 Encoding of an unconstrained whole number 14 11.9 General rules for encoding a length determinant . 14 12 Encoding the boolean type . 16 13 Encoding the integer type . 16 14 Encoding the enumerated ty
38、pe 17 15 Encoding the real type 18 16 Encoding the bitstring type . 18 17 Encoding the octetstring type . 19 18 Encoding the null type 19 19 Encoding the sequence type 19 20 Encoding the sequence-of type . 20 iv Rec. ITU-T X.691 (08/2015) 21 Encoding the set type 21 22 Encoding the set-of type . 21
39、23 Encoding the choice type 22 24 Encoding the object identifier type . 22 25 Encoding the relative object identifier type 23 26 Encoding the internationalized resource reference type . 23 27 Encoding the relative internationalized resource reference type 23 28 Encoding the embedded-pdv type. 23 29
40、Encoding of a value of the external type 23 30 Encoding the restricted character string types 24 31 Encoding the unrestricted character string type 26 32 Encoding the time type, the useful time types, the defined time types and the additional time types . 26 32.1 General 26 32.2 Encoding subtypes wi
41、th the “Basic=Date“ property setting 31 32.3 Encoding subtypes with the “Basic=Time“ property setting . 33 32.4 Encoding subtypes with the “Basic=Date-Time“ property setting 36 32.5 Encoding subtypes with the “Basic=Interval Interval-type=SE“ property setting 36 32.6 Encoding subtypes with the “Basi
42、c=Interval Interval-type=D“ property setting . 36 32.7 Encoding subtypes with the “Basic=Interval Interval-type=SD“ or “Basic=Interval Interval-type=DE“ property setting . 37 32.8 Encoding subtypes with the “Basic=Rec-Interval Interval-type=SE“ property setting . 38 32.9 Encoding subtypes with the “
43、Basic=Rec-Interval Interval-type=D“ property setting . 39 32.10 Encoding subtypes with the “Basic=Rec-Interval Interval-type=SD“ or “Basic=Rec-Interval Interval-type=DE“ property setting 39 32.11 Encoding subtypes with mixed settings of the Basic property 40 33 Object identifiers for transfer syntax
44、es . 43 Annex A Example of encodings . 44 A.1 Record that does not use subtype constraints 44 A.1.1 ASN.1 description of the record structure . 44 A.1.2 ASN.1 description of a record value . 44 A.1.3 ALIGNED PER representation of this record value 44 A.1.4 UNALIGNED PER representation of this record
45、 value 45 A.2 Record that uses subtype constraints . 47 A.2.1 ASN.1 description of the record structure . 47 A.2.2 ASN.1 description of a record value . 47 A.2.3 ALIGNED PER representation of this record value 47 A.2.4 UNALIGNED PER representation of this record value 48 A.3 Record that uses extensi
46、on markers . 49 A.3.1 ASN.1 description of the record structure . 49 A.3.2 ASN.1 description of a record value . 50 A.3.3 ALIGNED PER representation of this record value 50 A.3.4 UNALIGNED PER representation of this record value 51 A.4 Record that uses extension addition groups 53 A.4.1 ASN.1 descri
47、ption of the record structure . 53 A.4.2 ASN.1 description of a record value . 53 A.4.3 ALIGNED PER representation of this record value 53 A.4.4 UNALIGNED PER representation of this record value 54 Annex B Combining PER-visible and non-PER-visible constraints . 55 B.1 General 55 B.2 Extensibility an
48、d visibility of constraints in PER 55 B.2.1 General 55 B.2.2 PER-visibility of constraints 56 B.2.3 Effective constraints 57 B.3 Examples . 58 Rec. ITU-T X.691 (08/2015) v Annex C Support for the PER algorithms . 60 Annex D Support for the ASN.1 rules of extensibility . 61 Annex E Tutorial annex on
49、concatenation of PER encodings 62 Annex F Identification of Encoding Rules 63 vi Rec. ITU-T X.691 (08/2015) Introduction Specifications Rec. ITU-T X.680 | ISO/IEC 8824-1, Rec. ITU-T X.681 | ISO/IEC 8824-2, Rec. ITU-T X.682 | ISO/IEC 8824-3, Rec. ITU-T X.683 | ISO/IEC 8824-4 together describe Abstract Syntax Notation One (ASN.1), a notation for the definition of messages to be exchanged between peer applications. This Recommendation | International Standard defines encoding rules that may be applied to values of typ
