ISO/IEC 8825-8:2021

INTERNATIONAL ISO/IEC
STANDARD 8825-8
Second edition
2021-06
Information technology — ASN.1
encoding rules —
Part 8:
Specification of JavaScript Object
Notation Encoding Rules (JER)
Reference number
©
ISO/IEC 2021
© ISO/IEC 2021
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ii © ISO/IEC 2021 – All rights reserved

Foreword
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This document was prepared by Joint Technical Committee 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.697 (02/2021).
This second edition cancels and replaces the first edition (ISO/IEC 8825-8:2018), which has been
technically revised.
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© ISO/IEC 2021 – All rights reserved iii

CONTENTS
Page
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 Object Specification . 2
3.3 Constraint Specification . 2
3.4 Parameterization of ASN.1 Specification . 2
3.5 Basic Encoding Rules (BER) . 2
3.6 Packed Encoding Rules (PER) . 2
3.7 Additional definitions . 2
4 Abbreviations . 3
5 Encodings specified by this Recommendation | International Standard . 3
6 Conformance . 4
7 General provisions . 4
7.1 Use of the type notation . 4
7.2 Constraints . 5
7.3 Type and value model used for encoding . 6
7.4 Types to be encoded . 6
7.5 Encoding instructions . 6
7.6 Production of a complete JER encoding . 7
8 Notation, lexical items and keywords used in JER encoding instructions . 7
9 Specifying JER encoding instructions . 8
10 Assigning a JER encoding instruction using a type prefix . 9
11 Assigning a JER encoding instruction using a JER encoding control section . 9
12 Identification of the targets for a JER encoding instruction . 9
12.1 General rules . 9
12.2 Types defined in the module . 10
12.3 Built-in types . 10
12.4 Types imported from another module . 10
13 Multiple assignment of JER encoding instructions . 10
13.1 Order in which multiple assignments are considered . 10
13.2 Effect of assigning a negating encoding instruction . 11
13.3 Multiple assignment of JER encoding instructions of the same category . 11
14 The ARRAY encoding instruction . 11
14.1 General . 11
Rec. ITU-T X.697 (02/2021) iii
© ISO/IEC 2021 – All rights reserved

14.2 Restrictions . 11
15 The BASE64 encoding instruction . 11
15.1 General . 11
15.2 Restrictions . 12
16 The NAME encoding instruction . 12
16.1 General . 12
16.2 Restrictions . 13
17 The OBJECT encoding instruction . 13
17.1 General . 13
17.2 Restrictions . 13
18 The TEXT encoding instruction . 13
18.1 General . 13
18.2 Restrictions . 14
19 The UNWRAPPED encoding instruction . 14
19.1 General . 14
19.2 Restrictions . 14
20 Encoding of boolean values . 14
21 Encoding of integer values . 15
22 Encoding of enumerated values . 15
23 Encoding of real values . 15
23.1 General . 15
23.2 Encoding of the special real values . 15
23.3 Encoding as a JSON number. 16
23.4 Encoding as a JSON object . 16
24 Encoding of bitstring values . 16
24.1 General . 16
24.2 Encoding of bitstring types with a fixed size . 16
24.3 Encoding of bitstring types with a variable size . 16
24.4 Alternative encoding of bitstring types with a JER-visible contents constraint . 16
25 Encoding of octetstring values . 17
25.1 General . 17
25.2 Encoding of an octetstring value as a JSON string containing a Base64 encoding . 17
25.3 Encoding of an octetstring value as a JSON string containing a hexadecimal encoding . 1
...