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JSON Binding of the Incident Object Description Exchange Format
RFC 8727

Document Type RFC - Proposed Standard (August 2020) Errata
Authors Takeshi Takahashi , Roman Danyliw , Mio Suzuki
Last updated 2023-03-30
RFC stream Internet Engineering Task Force (IETF)
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IESG Responsible AD Alexey Melnikov
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RFC 8727


Internet Engineering Task Force (IETF)                      T. Takahashi
Request for Comments: 8727                                          NICT
Category: Standards Track                                     R. Danyliw
ISSN: 2070-1721                                                     CERT
                                                               M. Suzuki
                                                                    NICT
                                                             August 2020

    JSON Binding of the Incident Object Description Exchange Format

Abstract

   The Incident Object Description Exchange Format (IODEF) defined in
   RFC 7970 provides an information model and a corresponding XML data
   model for exchanging incident and indicator information.  This
   document gives implementers and operators an alternative format to
   exchange the same information by defining an alternative data model
   implementation in JSON and its encoding in Concise Binary Object
   Representation (CBOR).

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc8727.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction
     1.1.  Requirements Language
   2.  IODEF Data Types
     2.1.  Abstract Data Type to JSON Data Type Mapping
     2.2.  Complex JSON Types
       2.2.1.  Integer
       2.2.2.  Multilingual Strings
       2.2.3.  Enum
       2.2.4.  Software and Software Reference
       2.2.5.  Structured Information
       2.2.6.  EXTENSION
   3.  IODEF JSON Data Model
     3.1.  Classes and Elements
     3.2.  Mapping between JSON and XML IODEF
   4.  Examples
     4.1.  Minimal Example
     4.2.  Indicators from a Campaign
   5.  Mapkeys
   6.  The IODEF Data Model (CDDL)
   7.  IANA Considerations
   8.  Security Considerations
   9.  References
     9.1.  Normative References
     9.2.  Informative References
   Appendix A.  Data Types Used in This Document
   Appendix B.  The IODEF Data Model (JSON Schema)
   Acknowledgments
   Authors' Addresses

1.  Introduction

   The Incident Object Description Exchange Format (IODEF) [RFC7970]
   defines a data representation for security incident reports and
   indicators commonly exchanged by operational security teams.  It
   facilitates the automated exchange of this information to enable
   mitigation and watch-and-warning.  An information model using Unified
   Modeling Language (UML) is defined in Section 3 of [RFC7970] and a
   corresponding Extensible Markup Language (XML) schema data model is
   defined in Section 8 of [RFC7970].  This UML-based information model
   and XML-based data model are referred to as IODEF UML and IODEF XML,
   respectively, in this document.

   IODEF documents are structured and thus suitable for machine
   processing.  They will streamline incident response operations.
   Another well-used and structured format that is suitable for machine
   processing is JavaScript Object Notation (JSON) [RFC8259].  To
   facilitate the automation of incident response operations, IODEF
   documents and implementations should support JSON representation and
   its encoding in Concise Binary Object Representation (CBOR)
   [RFC7049].

   This document defines an alternate implementation of the IODEF UML
   information model by specifying a JSON data model using Concise Data
   Definition Language (CDDL) [RFC8610] and a JSON Schema [JSON-SCHEMA].
   This JSON data model is referred to as IODEF JSON in this document.
   IODEF JSON provides all of the expressivity of IODEF XML.  It gives
   implementers and operators an alternative format to exchange the same
   information.

   The normative IODEF JSON data model is found in Section 6.  Sections
   2 and 3 describe the data types and elements of this data model.
   Section 4 provides examples.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  IODEF Data Types

   IODEF JSON implements the abstract data types specified in Section 2
   of [RFC7970].

2.1.  Abstract Data Type to JSON Data Type Mapping

   IODEF JSON uses native and derived JSON data types.  Table 1
   describes the mapping between the abstract data types in Section 2 of
   [RFC7970] and their corresponding implementations in IODEF JSON.

   +=================+==========================+================+
   | IODEF Data Type | Reference                | JSON Data Type |
   +=================+==========================+================+
   | INTEGER         | Section 2.1 of [RFC7970] | integer; see   |
   |                 |                          | Section 2.2.1  |
   +-----------------+--------------------------+----------------+
   | REAL            | Section 2.2 of [RFC7970] | "number" per   |
   |                 |                          | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | CHARACTER       | Section 2.3 of [RFC7970] | "string" per   |
   |                 |                          | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | STRING          | Section 2.3 of [RFC7970] | "string" per   |
   |                 |                          | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | ML_STRING       | Section 2.4 of [RFC7970] | see            |
   |                 |                          | Section 2.2.2  |
   +-----------------+--------------------------+----------------+
   | BYTE            | Section 2.5.1 of         | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | BYTE[]          | Section 2.5.1 of         | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | HEXBIN          | Section 2.5.2 of         | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | HEXBIN[]        | Section 2.5.2 of         | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | ENUM            | Section 2.6 of [RFC7970] | see            |
   |                 |                          | Section 2.2.3  |
   +-----------------+--------------------------+----------------+
   | DATETIME        | Section 2.7 of [RFC7970] | "string" per   |
   |                 |                          | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | TIMEZONE        | Section 2.8 of [RFC7970] | "string" per   |
   |                 |                          | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | PORTLIST        | Section 2.9 of [RFC7970] | "string" per   |
   |                 |                          | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | POSTAL          | Section 2.10 of          | ML_STRING; see |
   |                 | [RFC7970]                | Section 2.2.2  |
   +-----------------+--------------------------+----------------+
   | PHONE           | Section 2.11 of          | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | EMAIL           | Section 2.12 of          | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | URL             | Section 2.13 of          | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | ID              | Section 2.14 of          | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | IDREF           | Section 2.14 of          | "string" per   |
   |                 | [RFC7970]                | [RFC8259]      |
   +-----------------+--------------------------+----------------+
   | SOFTWARE        | Section 2.15 of          | see            |
   |                 | [RFC7970]                | Section 2.2.4  |
   +-----------------+--------------------------+----------------+
   | STRUCTUREDINFO  | Section 4.4 of [RFC7203] | see            |
   |                 |                          | Section 2.2.5  |
   +-----------------+--------------------------+----------------+
   | EXTENSION       | Section 2.16 of          | see            |
   |                 | [RFC7970]                | Section 2.2.6  |
   +-----------------+--------------------------+----------------+

                       Table 1: JSON Data Types

   +=================+================+=============================+
   | IODEF Data Type | CBOR Data Type | CDDL Prelude [RFC8610]      |
   +=================+================+=============================+
   | INTEGER         | 0, 1, 6 tag 2, | integer                     |
   |                 | 6 tag 3        |                             |
   +-----------------+----------------+-----------------------------+
   | REAL            | 7 bits 26      | float32                     |
   +-----------------+----------------+-----------------------------+
   | CHARACTER       | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | STRING          | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | ML_STRING       | 5              | Maps/Structs (Section 3.5.1 |
   |                 |                | of [RFC8610])               |
   +-----------------+----------------+-----------------------------+
   | BYTE            | 6 tag 22       | eb64legacy                  |
   +-----------------+----------------+-----------------------------+
   | BYTE[]          | 6 tag 22       | eb64legacy                  |
   +-----------------+----------------+-----------------------------+
   | HEXBIN          | 6 tag 23       | eb16                        |
   +-----------------+----------------+-----------------------------+
   | HEXBIN[]        | 6 tag 23       | eb16                        |
   +-----------------+----------------+-----------------------------+
   | ENUM            | -              | Choices (Section 2.2.2 of   |
   |                 |                | [RFC8610])                  |
   +-----------------+----------------+-----------------------------+
   | DATETIME        | 6 tag 0        | tdate                       |
   +-----------------+----------------+-----------------------------+
   | TIMEZONE        | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | PORTLIST        | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | POSTAL          | 3              | ML_STRING (Section 2.2.2)   |
   +-----------------+----------------+-----------------------------+
   | PHONE           | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | EMAIL           | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | URL             | 6 tag 32       | uri                         |
   +-----------------+----------------+-----------------------------+
   | ID              | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | IDREF           | 3              | text                        |
   +-----------------+----------------+-----------------------------+
   | SOFTWARE        | 5              | Maps/Structs (Section 3.5.1 |
   |                 |                | of [RFC8610])               |
   +-----------------+----------------+-----------------------------+
   | STRUCTUREDINFO  | 5              | Maps/Structs (Section 3.5.1 |
   |                 |                | of [RFC8610])               |
   +-----------------+----------------+-----------------------------+
   | EXTENSION       | 5              | Maps/Structs (Section 3.5.1 |
   |                 |                | of [RFC8610])               |
   +-----------------+----------------+-----------------------------+

                        Table 2: CBOR Data Types

2.2.  Complex JSON Types

2.2.1.  Integer

   An integer is a subset of the "number" type of JSON, which represents
   signed digits encoded in Base 10.  The definition of this integer is
   "[ minus ] int" per [RFC8259], Section 6.

2.2.2.  Multilingual Strings

   A string that needs to be represented in a human-readable language
   different from the default encoding of the document is represented in
   the information model by the ML_STRING data type.  This data type is
   implemented as either an object with "value", "lang", and
   "translation-id" elements or a text string as defined in Section 6.
   An example is shown below.

   "MLStringType": {
     "value": "free-form text",                              # STRING
     "lang": "en",                                             # ENUM
     "translation-id": "jp2en0023"                           # STRING
   }

   Note that in figures throughout this document, some supplementary
   information follows "#", but these are not valid syntax in JSON;
   instead, they are intended to facilitate reader understanding.

2.2.3.  Enum

   Enum is an ordered list of acceptable string values.  Each value has
   a representative keyword.  Within the data model, the enumerated type
   keywords are used as attribute values.

2.2.4.  Software and Software Reference

   A particular version of software is represented in the information
   model by the SOFTWARE data type.  This software can be described by
   using a reference, a Uniform Resource Locator (URL) [RFC3986], or
   free-form text.  The SOFTWARE data type is implemented as an object
   with "SoftwareReference", "URL", and "Description" elements as
   defined in Section 6.  Examples are shown below.

   "SoftwareType": {
     "SoftwareReference": {...},                  # SoftwareReference
     "Description": ["MS Windows"]                           # STRING
   }

   SoftwareReference class is a reference to a particular version of
   software.  Examples are shown below.

   "SoftwareReference": {
     "value": "cpe:/a:google:chrome:59.0.3071.115",          # STRING
     "spec-name": "cpe",                                       # ENUM
     "dtype": "string"                                         # ENUM
   }

2.2.5.  Structured Information

   Information provided in the form of a structured string, such as an
   ID, or structured information, such as XML documents, is represented
   in the information model by the STRUCTUREDINFO data type.  Note that
   this type was originally specified in Section 4.4 of [RFC7203] as a
   basic structure of its extension classes.  The STRUCTUREDINFO data
   type is implemented as an object with "SpecID", "ext-SpecID",
   "ContentID", "RawData", and "Reference" elements.  An example for
   embedding a structured ID is shown below.

   "STRUCTUREDINFO": {
     "SpecID": "urn:ietf:params:xml:ns:mile:cwe:3.3",          # ENUM
     "ContentID": "CWE-89"                                   # STRING
   }

   When embedding the raw data, it should be encoded as a BYTE type
   object, as shown below.

   "STRUCTUREDINFO": {
     "SpecID": "urn:ietf:params:xml:ns:mile:mmdef:1.2",        # ENUM
     "RawData": "<<< encoded structured data >>>"              # BYTE
   }

   When embedding the raw data, base64 encoding defined in Section 4 of
   [RFC4648] MUST be used for JSON IODEF while binary representation
   MUST be used for CBOR IODEF.

2.2.6.  EXTENSION

   Information not otherwise represented in the IODEF can be added using
   the EXTENSION data type.  This data type is a generic extension
   mechanism.  The EXTENSION data type is implemented as an
   ExtensionType object with "value", "name", "dtype", "ext-dtype",
   "meaning", "formatid", "restriction", "ext-restriction", and
   "observable-id" elements.  An example for embedding a structured ID
   is shown below.

   "ExtensionType": {
     "value": "xxxxxxx",                                     # STRING
     "name": "Syslog",                                       # STRING
     "dtype": "string",                                        # ENUM
     "meaning": "Syslog from the security appliance X"       # STRING
   }

   Note that this data type is specified in [RFC7970] as its generic
   extension mechanism.  If a data item has internal structure that is
   intended to be processed outside of the IODEF framework, one may
   consider using the STRUCTUREDINFO data type mentioned in
   Section 2.2.5.

3.  IODEF JSON Data Model

3.1.  Classes and Elements

   The following table shows the list of IODEF classes and their
   elements and the corresponding sections in [RFC7970].  Note that the
   complete JSON schema is defined in Section 6 using CDDL.

   +===========================+============================+==========+
   | IODEF Class               | Class, Element, and        |Section in|
   |                           | Attribute                  |[RFC7970] |
   +===========================+============================+==========+
   | IODEF-Document            | version                    | 3.1      |
   |                           | lang?                      |          |
   |                           | format-id?                 |          |
   |                           | private-enum-name?         |          |
   |                           | private-enum-id?           |          |
   |                           | Incident+                  |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Incident                  | purpose                    | 3.2      |
   |                           | ext-purpose?               |          |
   |                           | status?                    |          |
   |                           | ext-status?                |          |
   |                           | lang?                      |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | IncidentID                 |          |
   |                           | AlternativeID?             |          |
   |                           | RelatedActivity*           |          |
   |                           | DetectTime?                |          |
   |                           | StartTime?                 |          |
   |                           | EndTime?                   |          |
   |                           | RecoveryTime?              |          |
   |                           | ReportTime?                |          |
   |                           | GenerationTime             |          |
   |                           | Description*               |          |
   |                           | Discovery*                 |          |
   |                           | Assessment*                |          |
   |                           | Method*                    |          |
   |                           | Contact+                   |          |
   |                           | EventData*                 |          |
   |                           | Indicator*                 |          |
   |                           | History?                   |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | IncidentID                | id                         | 3.4      |
   |                           | name                       |          |
   |                           | instance?                  |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   +---------------------------+----------------------------+----------+
   | AlternativeID             | restriction?               | 3.5      |
   |                           | ext-restriction?           |          |
   |                           | IncidentID+                |          |
   +---------------------------+----------------------------+----------+
   | RelatedActivity           | restriction?               | 3.6      |
   |                           | ext-restriction?           |          |
   |                           | IncidentID*                |          |
   |                           | URL*                       |          |
   |                           | ThreatActor*               |          |
   |                           | Campaign*                  |          |
   |                           | IndicatorID*               |          |
   |                           | Confidence?                |          |
   |                           | Description*               |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | ThreatActor               | restriction?               | 3.7      |
   |                           | ext-restriction?           |          |
   |                           | ThreatActorID*             |          |
   |                           | URL*                       |          |
   |                           | Description*               |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Campaign                  | restriction?               | 3.8      |
   |                           | ext-restriction?           |          |
   |                           | CampaignID*                |          |
   |                           | URL*                       |          |
   |                           | Description*               |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Contact                   | role                       | 3.9      |
   |                           | ext-role?                  |          |
   |                           | type                       |          |
   |                           | ext-type?                  |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | ContactName*               |          |
   |                           | ContactTitle*              |          |
   |                           | Description*               |          |
   |                           | RegistryHandle*            |          |
   |                           | PostalAddress*             |          |
   |                           | Email*                     |          |
   |                           | Telephone*                 |          |
   |                           | Timezone?                  |          |
   |                           | Contact*                   |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | RegistryHandle            | handle                     | 3.9.1    |
   |                           | registry                   |          |
   |                           | ext-registry?              |          |
   +---------------------------+----------------------------+----------+
   | PostalAddress             | type?                      | 3.9.2    |
   |                           | ext-type?                  |          |
   |                           | PAddress                   |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | Email                     | type?                      | 3.9.3    |
   |                           | ext-type?                  |          |
   |                           | EmailTo                    |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | Telephone                 | type?                      | 3.9.4    |
   |                           | ext-type?                  |          |
   |                           | TelephoneNumber            |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | Discovery                 | source?                    | 3.10     |
   |                           | ext-source?                |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | Description*               |          |
   |                           | Contact*                   |          |
   |                           | DetectionPattern*          |          |
   +---------------------------+----------------------------+----------+
   | DetectionPattern          | restriction?               | 3.10.1   |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | Application                |          |
   |                           | Description*               |          |
   |                           | DetectionConfiguration*    |          |
   +---------------------------+----------------------------+----------+
   | Method                    | restriction?               | 3.11     |
   |                           | ext-restriction?           |          |
   |                           | Reference*                 |          |
   |                           | Description*               |          |
   |                           | AttackPattern*             |          |
   |                           | Vulnerability*             |          |
   |                           | Weakness*                  |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Weakness                  | restriction?               | 4.5.5 in |
   |                           | ext-restriction?           |[RFC7203] |
   +---------------------------+----------------------------+----------+
   | Reference                 | observable-id?             | 3.11.1   |
   |                           | ReferenceName?             |          |
   |                           | URL*                       |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | Assessment                | occurrence?                | 3.12     |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | IncidentCategory*          |          |
   |                           | SystemImpact*              |          |
   |                           | BusinessImpact*            |          |
   |                           | TimeImpact*                |          |
   |                           | MonetaryImpact*            |          |
   |                           | IntendedImpact*            |          |
   |                           | Counter*                   |          |
   |                           | MitigatingFactor*          |          |
   |                           | Cause*                     |          |
   |                           | Confidence?                |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | SystemImpact              | severity?                  | 3.12.1   |
   |                           | completion?                |          |
   |                           | type                       |          |
   |                           | ext-type?                  |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | BusinessImpact            | severity?                  | 3.12.2   |
   |                           | ext-severity?              |          |
   |                           | type                       |          |
   |                           | ext-type?                  |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | TimeImpact                | value                      | 3.12.3   |
   |                           | severity?                  |          |
   |                           | metric                     |          |
   |                           | ext-metric?                |          |
   |                           | duration?                  |          |
   |                           | ext-duration?              |          |
   +---------------------------+----------------------------+----------+
   | MonetaryImpact            | value                      | 3.12.4   |
   |                           | severity?                  |          |
   |                           | currency?                  |          |
   +---------------------------+----------------------------+----------+
   | Confidence                | value                      | 3.12.5   |
   |                           | rating                     |          |
   |                           | ext-rating?                |          |
   +---------------------------+----------------------------+----------+
   | History                   | restriction?               | 3.13     |
   |                           | ext-restriction?           |          |
   |                           | HistoryItem+               |          |
   +---------------------------+----------------------------+----------+
   | HistoryItem               | action                     | 3.13.1   |
   |                           | ext-action?                |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | DateTime                   |          |
   |                           | IncidentID?                |          |
   |                           | Contact?                   |          |
   |                           | Description*               |          |
   |                           | DefinedCOA*                |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | EventData                 | restriction?               | 3.14     |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | Description*               |          |
   |                           | DetectTime?                |          |
   |                           | StartTime?                 |          |
   |                           | EndTime?                   |          |
   |                           | RecoveryTime?              |          |
   |                           | ReportTime?                |          |
   |                           | Contact*                   |          |
   |                           | Discovery*                 |          |
   |                           | Assessment?                |          |
   |                           | Method*                    |          |
   |                           | System*                    |          |
   |                           | Expectation*               |          |
   |                           | RecordData*                |          |
   |                           | EventData*                 |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Expectation               | action?                    | 3.15     |
   |                           | ext-action?                |          |
   |                           | severity?                  |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | Description*               |          |
   |                           | DefinedCOA*                |          |
   |                           | StartTime?                 |          |
   |                           | EndTime?                   |          |
   |                           | Contact?                   |          |
   +---------------------------+----------------------------+----------+
   | System                    | category?                  | 3.17     |
   |                           | ext-category?              |          |
   |                           | interface?                 |          |
   |                           | spoofed?                   |          |
   |                           | virtual?                   |          |
   |                           | ownership?                 |          |
   |                           | ext-ownership?             |          |
   |                           | restriction?               |          |
   |                           | ext-restriction?           |          |
   |                           | Node                       |          |
   |                           | NodeRole*                  |          |
   |                           | Service*                   |          |
   |                           | OperatingSystem*           |          |
   |                           | Counter*                   |          |
   |                           | AssetID*                   |          |
   |                           | Description*               |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Node                      | DomainData*                | 3.18     |
   |                           | Address*                   |          |
   |                           | PostalAddress?             |          |
   |                           | Location*                  |          |
   |                           | Counter*                   |          |
   +---------------------------+----------------------------+----------+
   | Address                   | value                      | 3.18.1   |
   |                           | category                   |          |
   |                           | ext-category?              |          |
   |                           | vlan-name?                 |          |
   |                           | vlan-num?                  |          |
   |                           | observable-id?             |          |
   +---------------------------+----------------------------+----------+
   | NodeRole                  | category                   | 3.18.2   |
   |                           | ext-category?              |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | Counter                   | value                      | 3.18.3   |
   |                           | type                       |          |
   |                           | ext-type?                  |          |
   |                           | unit                       |          |
   |                           | ext-unit?                  |          |
   |                           | meaning?                   |          |
   |                           | duration?                  |          |
   |                           | ext-duration?              |          |
   +---------------------------+----------------------------+----------+
   | DomainData                | system-status              | 3.19     |
   |                           | ext-system-status?         |          |
   |                           | domain-status              |          |
   |                           | ext-domain-status?         |          |
   |                           | observable-id?             |          |
   |                           | Name                       |          |
   |                           | DateDomainWasChecked?      |          |
   |                           | RegistrationDate?          |          |
   |                           | ExpirationDate?            |          |
   |                           | RelatedDNS*                |          |
   |                           | Nameservers*               |          |
   |                           | DomainContacts?            |          |
   +---------------------------+----------------------------+----------+
   | Nameservers               | Server                     | 3.19.1   |
   |                           | Address*                   |          |
   +---------------------------+----------------------------+----------+
   | DomainContacts            | SameDomainContact?         | 3.19.2   |
   |                           | Contact+                   |          |
   +---------------------------+----------------------------+----------+
   | Service                   | ip-protocol?               | 3.20     |
   |                           | observable-id?             |          |
   |                           | ServiceName?               |          |
   |                           | Port?                      |          |
   |                           | Portlist?                  |          |
   |                           | ProtoCode?                 |          |
   |                           | ProtoType?                 |          |
   |                           | ProtoField?                |          |
   |                           | ApplicationHeaderField*    |          |
   |                           | EmailData?                 |          |
   |                           | Application?               |          |
   +---------------------------+----------------------------+----------+
   | ServiceName               | IANAService?               | 3.20.1   |
   |                           | URL*                       |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | EmailData                 | observable-id?             | 3.21     |
   |                           | EmailTo*                   |          |
   |                           | EmailFrom?                 |          |
   |                           | EmailSubject?              |          |
   |                           | EmailX-Mailer?             |          |
   |                           | EmailHeaderField*          |          |
   |                           | EmailHeaders?              |          |
   |                           | EmailBody?                 |          |
   |                           | EmailMessage?              |          |
   |                           | HashData*                  |          |
   |                           | Signature*                 |          |
   +---------------------------+----------------------------+----------+
   | RecordData                | restriction?               | 3.22.1   |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | DateTime?                  |          |
   |                           | Description*               |          |
   |                           | Application?               |          |
   |                           | RecordPattern*             |          |
   |                           | RecordItem*                |          |
   |                           | URL*                       |          |
   |                           | FileData*                  |          |
   |                           |WindowsRegistryKeysModified*|          |
   |                           | CertificateData*           |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | RecordPattern             | type                       | 3.22.2   |
   |                           | ext-type?                  |          |
   |                           | offset?                    |          |
   |                           | offsetunit?                |          |
   |                           | ext-offsetunit?            |          |
   |                           | instance?                  |          |
   |                           | value                      |          |
   +---------------------------+----------------------------+----------+
   |WindowsRegistryKeysModified| observable-id?             | 3.23     |
   |                           | Key+                       |          |
   +---------------------------+----------------------------+----------+
   | Key                       | registryaction?            | 3.23.1   |
   |                           | ext-registryaction?        |          |
   |                           | observable-id?             |          |
   |                           | KeyName                    |          |
   |                           | KeyValue?                  |          |
   +---------------------------+----------------------------+----------+
   | CertificateData           | restriction?               | 3.24     |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | Certificate+               |          |
   +---------------------------+----------------------------+----------+
   | Certificate               | observable-id?             | 3.24.1   |
   |                           | X509Data                   |          |
   |                           | Description*               |          |
   +---------------------------+----------------------------+----------+
   | FileData                  | restriction?               | 3.25     |
   |                           | ext-restriction?           |          |
   |                           | observable-id?             |          |
   |                           | File+                      |          |
   +---------------------------+----------------------------+----------+
   | File                      | observable-id?             | 3.25.1   |
   |                           | FileName?                  |          |
   |                           | FileSize?                  |          |
   |                           | FileType?                  |          |
   |                           | URL*                       |          |
   |                           | HashData?                  |          |
   |                           | Signature*                 |          |
   |                           | AssociatedSoftware?        |          |
   |                           | FileProperties*            |          |
   +---------------------------+----------------------------+----------+
   | HashData                  | scope                      | 3.26     |
   |                           | HashTargetID?              |          |
   |                           | Hash*                      |          |
   |                           | FuzzyHash*                 |          |
   +---------------------------+----------------------------+----------+
   | Hash                      | DigestMethod               | 3.26.1   |
   |                           | DigestValue                |          |
   |                           | CanonicalizationMethod?    |          |
   |                           | Application?               |          |
   +---------------------------+----------------------------+----------+
   | FuzzyHash                 | FuzzyHashValue+            | 3.26.2   |
   |                           | Application?               |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | Indicator                 | restriction?               | 3.29     |
   |                           | ext-restriction?           |          |
   |                           | IndicatorID                |          |
   |                           | AlternativeIndicatorID*    |          |
   |                           | Description*               |          |
   |                           | StartTime?                 |          |
   |                           | EndTime?                   |          |
   |                           | Confidence?                |          |
   |                           | Contact*                   |          |
   |                           | Observable?                |          |
   |                           | uid-ref?                   |          |
   |                           | IndicatorExpression?       |          |
   |                           | IndicatorReference?        |          |
   |                           | NodeRole*                  |          |
   |                           | AttackPhase*               |          |
   |                           | Reference*                 |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | IndicatorID               | id                         | 3.29.1   |
   |                           | name                       |          |
   |                           | version                    |          |
   +---------------------------+----------------------------+----------+
   | AlternativeIndicatorID    | restriction?               | 3.29.2   |
   |                           | ext-restriction?           |          |
   |                           | IndicatorID+               |          |
   +---------------------------+----------------------------+----------+
   | Observable                | restriction?               | 3.29.3   |
   |                           | ext-restriction?           |          |
   |                           | System?                    |          |
   |                           | Address?                   |          |
   |                           | DomainData?                |          |
   |                           | Service?                   |          |
   |                           | EmailData?                 |          |
   |                           |WindowsRegistryKeysModified?|          |
   |                           | FileData?                  |          |
   |                           | CertificateData?           |          |
   |                           | RegistryHandle?            |          |
   |                           | RecordData?                |          |
   |                           | EventData?                 |          |
   |                           | Incident?                  |          |
   |                           | Expectation?               |          |
   |                           | Reference?                 |          |
   |                           | Assessment?                |          |
   |                           | DetectionPattern?          |          |
   |                           | HistoryItem?               |          |
   |                           | BulkObservable?            |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | BulkObservable            | type?                      | 3.29.3.1 |
   |                           | ext-type?                  |          |
   |                           | BulkObservableFormat?      |          |
   |                           | BulkObservableList         |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | BulkObservableFormat      | Hash?                      |3.29.3.1.1|
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | IndicatorExpression       | operator?                  | 3.29.4   |
   |                           | ext-operator?              |          |
   |                           | IndicatorExpression*       |          |
   |                           | Observable*                |          |
   |                           | uid-ref*                   |          |
   |                           | IndicatorReference*        |          |
   |                           | Confidence?                |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+
   | IndicatorReference        | uid-ref?                   | 3.29.7   |
   |                           | euid-ref?                  |          |
   |                           | version?                   |          |
   +---------------------------+----------------------------+----------+
   | AttackPhase               | AttackPhaseID*             | 3.29.8   |
   |                           | URL*                       |          |
   |                           | Description*               |          |
   |                           | AdditionalData*            |          |
   +---------------------------+----------------------------+----------+

                           Table 3: IODEF Classes

3.2.  Mapping between JSON and XML IODEF

   *  Attributes and elements of each class in the XML IODEF document
      are both presented as JSON attributes in the JSON IODEF document,
      and the order of their appearances is ignored.

   *  Flow class is deleted, and classes with its instances now directly
      have instances of the EventData class that used to belong to the
      Flow class.

   *  ApplicationHeader class is deleted, and classes with its instances
      now directly have instances of the ApplicationHeaderField class
      that used to belong to the ApplicationHeader class.

   *  SignatureData class is deleted, and classes with its instances now
      directly have instances of the Signature class that used to belong
      to the SignatureData class.

   *  IndicatorData class is deleted, and classes with its instances now
      directly have instances of the Indicator class that used to belong
      to the IndicatorData class.

   *  ObservableReference class is deleted, and classes with its
      instances now directly have uid-ref as an element.

   *  Record class is deleted, and classes with its instances now
      directly have instances of the RecordData class that used to
      belong to the Record class.

   *  The MLStringType was modified to support simple string by allowing
      the type to have not only a predefined object type but also a text
      type, in order to allow simple descriptions of elements of the
      type.  Implementations need to be capable of parsing an
      MLStringType that could take the form of both text and an object.

   *  The elements of the ML_STRING type in the XML IODEF document are
      presented as either STRING type or ML_STRING type in the JSON
      IODEF document.  When converting from the XML IODEF document to
      the JSON IODEF document, or vice versa, the information contained
      in the original data of the ML_STRING type must be preserved.
      When STRING is used instead of ML_STRING, parsers can assume that
      its "xml:lang" is set to "en".

   *  Data models of the extension classes defined by [RFC7203] and
      referenced by [RFC7970] are represented by the STRUCTUREDINFO
      class defined in this document.

   *  Signature, X509Data, and RawData are encoded using base64 encoding
      for JSON IODEF and binary representation for CBOR IODEF to
      represent them as BYTE objects.

   *  EmailBody represents a whole message body including MIME structure
      in the same manner defined in [RFC7970].  In case of an email
      composed of a MIME multipart, the EmailBody contains multiple body
      parts separated by boundary strings.

   *  The "ipv6-net-mask" type attribute of the BulkObservable class
      remains available for the purpose of backward compatibility, but
      the use of this attribute is not recommended because IPv6 does not
      use netmask any more.

   *  ENUM values in this document are extensible and managed by IANA,
      which is also the case in [RFC7970].  The values in the table are
      used both by [RFC7970] implementations and by their JSON (and
      CBOR) bindings as specified by this document.

   *  This document uses JSON's "number" type to represent integers that
      only have full precision for integer values between -2^(53) and
      2^(53).  When dealing with integers outside the range, this issue
      needs to be considered.

   *  Binaries are encoded in bytes.  Note that XML IODEF in [RFC7970]
      uses HEXBIN due to the incapability of XML for embedding binaries
      as they are.

4.  Examples

   This section provides examples of IODEF documents.  These examples do
   not represent the full capabilities of the data model or the only way
   to encode particular information.

4.1.  Minimal Example

   A document containing only the mandatory elements and attributes is
   shown below in JSON and CBOR, respectively.

   {
     "version": "2.0",
     "lang": "en",
     "Incident": [{
         "purpose": "reporting",
         "restriction": "private",
         "IncidentID": {
           "id": "492382",
           "name": "csirt.example.com"
         },
         "GenerationTime": "2015-07-18T09:00:00-05:00",
         "Contact": [{
             "type": "organization",
             "role": "creator",
             "Email": [{"EmailTo": "contact@csirt.example.com"}]
         }]
     }]
   }

                    Figure 1: A Minimal Example in JSON

   A3                                    # map(3)
      37                                 # negative(23)
      63                                 # text(3)
         322E30                          # "2.0"
      36                                 # negative(22)
      62                                 # text(2)
         656E                            # "en"
      32                                 # negative(18)
      81                                 # array(1)
         A5                              # map(5)
            21                           # negative(1)
            69                           # text(9)
               7265706F7274696E67        # "reporting"
            29                           # negative(9)
            67                           # text(7)
               70726976617465            # "private"
            02                           # unsigned(2)
            A2                           # map(2)
               12                        # unsigned(18)
               66                        # text(6)
                  343932333832           # "492382"
               2E                        # negative(14)
               71                        # text(17)
                  63736972742E6578616D706C652E636F6D
                                         # "csirt.example.com"
            0A                           # unsigned(10)
            78 19                        # text(25)
               323031352D30372D31385430393A30303A30302D30353A3030
                                         # "2015-07-18T09:00:00
                                         # -05:00"
            0E                           # unsigned(14)
            81                           # array(1)
               A3                        # map(3)
                  18 1C                  # unsigned(28)
                  6C                     # text(12)
                     6F7267616E697A6174696F6E # "organization"
                  18 1A                  # unsigned(26)
                  67                     # text(7)
                     63726561746F72      # "creator"
                  18 22                  # unsigned(34)
                  81                     # array(1)
                     A1                  # map(1)
                        18 29            # unsigned(41)
                        78 19            # text(25)
                           636F6E746163744063736972742E6578616D70
                           6C652E636F6D
                                         # "contact@csirt.example.com"

                    Figure 2: A Minimal Example in CBOR

4.2.  Indicators from a Campaign

   An example of C2 domains from a given campaign is shown below in JSON
   and CBOR, respectively.

   {
     "version": "2.0",
     "lang": "en",
     "Incident": [{
       "purpose": "watch",
       "restriction": "green",
       "IncidentID": {
         "id": "897923",
         "name": "csirt.example.com"
       },
       "RelatedActivity": [{
         "ThreatActor": [{
           "ThreatActorID": ["TA-12-AGGRESSIVE-BUTTERFLY"],
           "Description": ["Aggressive Butterfly"]}],
         "Campaign": [{
           "CampaignID": ["C-2015-59405"],
           "Description": ["Orange Giraffe"]
         }]
       }],
       "GenerationTime": "2015-10-02T11:18:00-05:00",
       "Description": ["Summarizes the Indicators of Compromise for the
         Orange Giraffe campaign of the Aggressive Butterfly crime
         gang."],
       "Assessment": [{
         "Impact": [{"BusinessImpact": {"type": "breach-proprietary"}}]
       }],
       "Contact": [{
         "type": "organization",
         "role": "creator",
         "ContactName": ["CSIRT for example.com"],
         "Email": [{
           "EmailTo": "contact@csirt.example.com"
         }]
       }],
       "Indicator": [{
         "IndicatorID": {
           "id": "G90823490",
           "name": "csirt.example.com",
           "version": "1"
         },
         "Description": ["C2 domains"],
         "StartTime": "2014-12-02T11:18:00-05:00",
         "Observable": {
           "BulkObservable": {
             "type": "domain-name",
             "BulkObservableList": "kj290023j09r34.example.com"}
         }
       }]
     }]
   }

                Figure 3: Indicators from a Campaign in JSON

   A3                                      # map(3)
      37                                   # negative(23)
      63                                   # text(3)
         322E30                            # "2.0"
      36                                   # negative(22)
      62                                   # text(2)
         656E                              # "en"
      32                                   # negative(18)
      81                                   # array(1)
         A9                                # map(9)
            21                             # negative(1)
            65                             # text(5)
               7761746368                  # "watch"
            29                             # negative(9)
            65                             # text(5)
               677265656E                  # "green"
            02                             # unsigned(2)
            A2                             # map(2)
               12                          # unsigned(18)
               66                          # text(6)
                  383937393233             # "897923"
               2E                          # negative(14)
               71                          # text(17)
                  63736972742E6578616D706C652E636F6D
                                           # "csirt.example.com"
            04                             # unsigned(4)
            81                             # array(1)
               A2                          # map(2)
                  14                       # unsigned(20)
                  81                       # array(1)
                     A2                    # map(2)
                        18 18              # unsigned(24)
                        81                 # array(1)
                           78 1A           # text(26)
                              54412D31322D414747524553534956452D4
                              25554544552464C59
                                           # "TA-12-AGGRESSIVE
                                           # -BUTTERFLY"
                        24                 # negative(4)
                        81                 # array(1)
                           74              # text(20)
                              41676772657373697665204275747465726
                              66C79
                                           # "Aggressive Butterfly"
                  15                       # unsigned(21)
                  81                       # array(1)
                     A2                    # map(2)
                        18 19              # unsigned(25)
                        81                 # array(1)
                           6C              # text(12)
                              432D323031352D3539343035
                                           # "C-2015-59405"
                        24                 # negative(4)
                        81                 # array(1)
                           6E              # text(14)
                              4F72616E67652047697261666665
    # "Orange Giraffe"
            0A                             # unsigned(10)
            78 19                          # text(25)
               323031352D31302D30325431313A31383A30302D30353A3030
                                          # "2015-10-02T11:18:00-05:00"
            24                             # negative(4)
            81                             # array(1)
               78 6F                       # text(111)
                  53756D6D6172697A65732074686520496E64696361746F7
                  273206F6620436F6D70726F6D69736520666F7220746865
                  204F72616E676520476972616666652063616D706169676
                  E206F662074686520416767726573736976652042757474
                  6572666C79206372696D652067616E672E
                                           # "Summarizes the Indicators
                                           # of Compromise for the
                                           # Orange Giraffe campaign
                                           # of the Aggressive
                                           # Butterfly crime gang."
            0C                             # unsigned(12)
            81                             # array(1)
               A1                          # map(1)
                  18 3F                    # unsigned(63)
                  81                       # array(1)
                     A1                    # map(1)
                        18 41              # unsigned(65)
                        A1                 # map(1)
                           18 1C           # unsigned(28)
                           72              # text(18)
                              6272656163682D70726F7072696574617279
                                           # "breach-proprietary"
            0E                             # unsigned(14)
            81                             # array(1)
               A4                          # map(4)
                  18 1C                    # unsigned(28)
                  6C                       # text(12)
                     6F7267616E697A6174696F6E
                                           # "organization"
                  18 1A                    # unsigned(26)
                  67                       # text(7)
                     63726561746F72        # "creator"
                  18 1E                    # unsigned(30)
                  81                       # array(1)
                     75                    # text(21)
                        435349525420666F72206578616D706C652E636F6D
                                           # "CSIRT for example.com"
                  18 22                    # unsigned(34)
                  81                       # array(1)
                     A1                    # map(1)
                        18 29              # unsigned(41)
                        78 19              # text(25)
                           636F6E746163744063736972742E6578616D70
                           6C652E636F6D
                                          # "contact@csirt.example.com"
            10                             # unsigned(16)
            81                             # array(1)
               A4                          # map(4)
                  16                       # unsigned(22)
                  A3                       # map(3)
                     12                    # unsigned(18)
                     69                    # text(9)
                        473930383233343930 # "G90823490"
                     2E                    # negative(14)
                     71                    # text(17)
                        63736972742E6578616D706C652E636F6D
                                           # "csirt.example.com"
                     37                    # negative(23)
                     61                    # text(1)
                        31                 # "1"
                  24                       # negative(4)
                  81                       # array(1)
                     6A                    # text(10)
                        433220646F6D61696E73 # "C2 domains"
                  06                       # unsigned(6)
                  78 19                    # text(25)
                     323031342D31322D30325431313A31383A30302D30353A3030
                                          # "2014-12-02T11:18:00-05:00"
                  18 AB                    # unsigned(171)
                  A1                       # map(1)
                     18 B0                 # unsigned(176)
                     A2                    # map(2)
                        18 1C              # unsigned(28)
                        6B                 # text(11)
                           646F6D61696E2D6E616D65
                                           # "domain-name"
                        18 B2              # unsigned(178)
                        78 1A              # text(26)
                           6B6A3239303032336A30397233342E6578616D
                           706C652E636F6D
                                         # "kj290023j09r34.example.com"

                Figure 4: Indicators from a Campaign in CBOR

5.  Mapkeys

   The mapkeys are provided in Table 4 for minimizing the CBOR size.

   +===================================+=========+
   | mapkey                            | cborkey |
   +===================================+=========+
   | iodef-version                     | -24     |
   +-----------------------------------+---------+
   | iodef-lang                        | -23     |
   +-----------------------------------+---------+
   | iodef-format-id                   | -22     |
   +-----------------------------------+---------+
   | iodef-private-enum-name           | -21     |
   +-----------------------------------+---------+
   | iodef-private-enum-id             | -20     |
   +-----------------------------------+---------+
   | iodef-Incident                    | -19     |
   +-----------------------------------+---------+
   | iodef-AdditionalData              | -18     |
   +-----------------------------------+---------+
   | iodef-value                       | -17     |
   +-----------------------------------+---------+
   | iodef-translation-id              | -16     |
   +-----------------------------------+---------+
   | iodef-name                        | -15     |
   +-----------------------------------+---------+
   | iodef-dtype                       | -14     |
   +-----------------------------------+---------+
   | iodef-ext-dtype                   | -13     |
   +-----------------------------------+---------+
   | iodef-meaning                     | -12     |
   +-----------------------------------+---------+
   | iodef-formatid                    | -11     |
   +-----------------------------------+---------+
   | iodef-restriction                 | -10     |
   +-----------------------------------+---------+
   | iodef-ext-restriction             | -9      |
   +-----------------------------------+---------+
   | iodef-observable-id               | -8      |
   +-----------------------------------+---------+
   | iodef-SoftwareReference           | -7      |
   +-----------------------------------+---------+
   | iodef-URL                         | -6      |
   +-----------------------------------+---------+
   | iodef-Description                 | -5      |
   +-----------------------------------+---------+
   | iodef-spec-name                   | -4      |
   +-----------------------------------+---------+
   | iodef-ext-spec-name               | -3      |
   +-----------------------------------+---------+
   | iodef-purpose                     | -2      |
   +-----------------------------------+---------+
   | iodef-ext-purpose                 | -1      |
   +-----------------------------------+---------+
   | iodef-status                      | 0       |
   +-----------------------------------+---------+
   | iodef-ext-status                  | 1       |
   +-----------------------------------+---------+
   | iodef-IncidentID                  | 2       |
   +-----------------------------------+---------+
   | iodef-AlternativeID               | 3       |
   +-----------------------------------+---------+
   | iodef-RelatedActivity             | 4       |
   +-----------------------------------+---------+
   | iodef-DetectTime                  | 5       |
   +-----------------------------------+---------+
   | iodef-StartTime                   | 6       |
   +-----------------------------------+---------+
   | iodef-EndTime                     | 7       |
   +-----------------------------------+---------+
   | iodef-RecoveryTime                | 8       |
   +-----------------------------------+---------+
   | iodef-ReportTime                  | 9       |
   +-----------------------------------+---------+
   | iodef-GenerationTime              | 10      |
   +-----------------------------------+---------+
   | iodef-Discovery                   | 11      |
   +-----------------------------------+---------+
   | iodef-Assessment                  | 12      |
   +-----------------------------------+---------+
   | iodef-Method                      | 13      |
   +-----------------------------------+---------+
   | iodef-Contact                     | 14      |
   +-----------------------------------+---------+
   | iodef-EventData                   | 15      |
   +-----------------------------------+---------+
   | iodef-Indicator                   | 16      |
   +-----------------------------------+---------+
   | iodef-History                     | 17      |
   +-----------------------------------+---------+
   | iodef-id                          | 18      |
   +-----------------------------------+---------+
   | iodef-instance                    | 19      |
   +-----------------------------------+---------+
   | iodef-ThreatActor                 | 20      |
   +-----------------------------------+---------+
   | iodef-Campaign                    | 21      |
   +-----------------------------------+---------+
   | iodef-IndicatorID                 | 22      |
   +-----------------------------------+---------+
   | iodef-Confidence                  | 23      |
   +-----------------------------------+---------+
   | iodef-ThreatActorID               | 24      |
   +-----------------------------------+---------+
   | iodef-CampaignID                  | 25      |
   +-----------------------------------+---------+
   | iodef-role                        | 26      |
   +-----------------------------------+---------+
   | iodef-ext-role                    | 27      |
   +-----------------------------------+---------+
   | iodef-type                        | 28      |
   +-----------------------------------+---------+
   | iodef-ext-type                    | 29      |
   +-----------------------------------+---------+
   | iodef-ContactName                 | 30      |
   +-----------------------------------+---------+
   | iodef-ContactTitle                | 31      |
   +-----------------------------------+---------+
   | iodef-RegistryHandle              | 32      |
   +-----------------------------------+---------+
   | iodef-PostalAddress               | 33      |
   +-----------------------------------+---------+
   | iodef-Email                       | 34      |
   +-----------------------------------+---------+
   | iodef-Telephone                   | 35      |
   +-----------------------------------+---------+
   | iodef-Timezone                    | 36      |
   +-----------------------------------+---------+
   | iodef-handle                      | 37      |
   +-----------------------------------+---------+
   | iodef-registry                    | 38      |
   +-----------------------------------+---------+
   | iodef-ext-registry                | 39      |
   +-----------------------------------+---------+
   | iodef-PAddress                    | 40      |
   +-----------------------------------+---------+
   | iodef-EmailTo                     | 41      |
   +-----------------------------------+---------+
   | iodef-TelephoneNumber             | 42      |
   +-----------------------------------+---------+
   | iodef-source                      | 43      |
   +-----------------------------------+---------+
   | iodef-ext-source                  | 44      |
   +-----------------------------------+---------+
   | iodef-DetectionPattern            | 45      |
   +-----------------------------------+---------+
   | iodef-DetectionConfiguration      | 46      |
   +-----------------------------------+---------+
   | iodef-Application                 | 47      |
   +-----------------------------------+---------+
   | iodef-Reference                   | 48      |
   +-----------------------------------+---------+
   | iodef-AttackPattern               | 49      |
   +-----------------------------------+---------+
   | iodef-Vulnerability               | 50      |
   +-----------------------------------+---------+
   | iodef-Weakness                    | 51      |
   +-----------------------------------+---------+
   | iodef-SpecID                      | 52      |
   +-----------------------------------+---------+
   | iodef-ext-SpecID                  | 53      |
   +-----------------------------------+---------+
   | iodef-ContentID                   | 54      |
   +-----------------------------------+---------+
   | iodef-RawData                     | 55      |
   +-----------------------------------+---------+
   | iodef-Platform                    | 56      |
   +-----------------------------------+---------+
   | iodef-Scoring                     | 57      |
   +-----------------------------------+---------+
   | iodef-ReferenceName               | 58      |
   +-----------------------------------+---------+
   | iodef-specIndex                   | 59      |
   +-----------------------------------+---------+
   | iodef-ID                          | 60      |
   +-----------------------------------+---------+
   | iodef-occurrence                  | 61      |
   +-----------------------------------+---------+
   | iodef-IncidentCategory            | 62      |
   +-----------------------------------+---------+
   | iodef-Impact                      | 63      |
   +-----------------------------------+---------+
   | iodef-SystemImpact                | 64      |
   +-----------------------------------+---------+
   | iodef-BusinessImpact              | 65      |
   +-----------------------------------+---------+
   | iodef-TimeImpact                  | 66      |
   +-----------------------------------+---------+
   | iodef-MonetaryImpact              | 67      |
   +-----------------------------------+---------+
   | iodef-IntendedImpact              | 68      |
   +-----------------------------------+---------+
   | iodef-Counter                     | 69      |
   +-----------------------------------+---------+
   | iodef-MitigatingFactor            | 70      |
   +-----------------------------------+---------+
   | iodef-Cause                       | 71      |
   +-----------------------------------+---------+
   | iodef-severity                    | 72      |
   +-----------------------------------+---------+
   | iodef-completion                  | 73      |
   +-----------------------------------+---------+
   | iodef-ext-severity                | 74      |
   +-----------------------------------+---------+
   | iodef-metric                      | 75      |
   +-----------------------------------+---------+
   | iodef-ext-metric                  | 76      |
   +-----------------------------------+---------+
   | iodef-duration                    | 77      |
   +-----------------------------------+---------+
   | iodef-ext-duration                | 78      |
   +-----------------------------------+---------+
   | iodef-currency                    | 79      |
   +-----------------------------------+---------+
   | iodef-rating                      | 80      |
   +-----------------------------------+---------+
   | iodef-ext-rating                  | 81      |
   +-----------------------------------+---------+
   | iodef-HistoryItem                 | 82      |
   +-----------------------------------+---------+
   | iodef-action                      | 83      |
   +-----------------------------------+---------+
   | iodef-ext-action                  | 84      |
   +-----------------------------------+---------+
   | iodef-DateTime                    | 85      |
   +-----------------------------------+---------+
   | iodef-DefinedCOA                  | 86      |
   +-----------------------------------+---------+
   | iodef-System                      | 87      |
   +-----------------------------------+---------+
   | iodef-Expectation                 | 88      |
   +-----------------------------------+---------+
   | iodef-RecordData                  | 89      |
   +-----------------------------------+---------+
   | iodef-category                    | 90      |
   +-----------------------------------+---------+
   | iodef-ext-category                | 91      |
   +-----------------------------------+---------+
   | iodef-interface                   | 92      |
   +-----------------------------------+---------+
   | iodef-spoofed                     | 93      |
   +-----------------------------------+---------+
   | iodef-virtual                     | 94      |
   +-----------------------------------+---------+
   | iodef-ownership                   | 95      |
   +-----------------------------------+---------+
   | iodef-ext-ownership               | 96      |
   +-----------------------------------+---------+
   | iodef-Node                        | 97      |
   +-----------------------------------+---------+
   | iodef-NodeRole                    | 98      |
   +-----------------------------------+---------+
   | iodef-Service                     | 99      |
   +-----------------------------------+---------+
   | iodef-OperatingSystem             | 100     |
   +-----------------------------------+---------+
   | iodef-AssetID                     | 101     |
   +-----------------------------------+---------+
   | iodef-DomainData                  | 102     |
   +-----------------------------------+---------+
   | iodef-Address                     | 103     |
   +-----------------------------------+---------+
   | iodef-Location                    | 104     |
   +-----------------------------------+---------+
   | iodef-vlan-name                   | 105     |
   +-----------------------------------+---------+
   | iodef-vlan-num                    | 106     |
   +-----------------------------------+---------+
   | iodef-unit                        | 107     |
   +-----------------------------------+---------+
   | iodef-ext-unit                    | 108     |
   +-----------------------------------+---------+
   | iodef-system-status               | 109     |
   +-----------------------------------+---------+
   | iodef-ext-system-status           | 110     |
   +-----------------------------------+---------+
   | iodef-domain-status               | 111     |
   +-----------------------------------+---------+
   | iodef-ext-domain-status           | 112     |
   +-----------------------------------+---------+
   | iodef-Name                        | 113     |
   +-----------------------------------+---------+
   | iodef-DateDomainWasChecked        | 114     |
   +-----------------------------------+---------+
   | iodef-RegistrationDate            | 115     |
   +-----------------------------------+---------+
   | iodef-ExpirationDate              | 116     |
   +-----------------------------------+---------+
   | iodef-RelatedDNS                  | 117     |
   +-----------------------------------+---------+
   | iodef-NameServers                 | 118     |
   +-----------------------------------+---------+
   | iodef-DomainContacts              | 119     |
   +-----------------------------------+---------+
   | iodef-Server                      | 120     |
   +-----------------------------------+---------+
   | iodef-SameDomainContact           | 121     |
   +-----------------------------------+---------+
   | iodef-ip-protocol                 | 122     |
   +-----------------------------------+---------+
   | iodef-ServiceName                 | 123     |
   +-----------------------------------+---------+
   | iodef-Port                        | 124     |
   +-----------------------------------+---------+
   | iodef-Portlist                    | 125     |
   +-----------------------------------+---------+
   | iodef-ProtoCode                   | 126     |
   +-----------------------------------+---------+
   | iodef-ProtoType                   | 127     |
   +-----------------------------------+---------+
   | iodef-ProtoField                  | 128     |
   +-----------------------------------+---------+
   | iodef-ApplicationHeaderField      | 129     |
   +-----------------------------------+---------+
   | iodef-EmailData                   | 130     |
   +-----------------------------------+---------+
   | iodef-IANAService                 | 131     |
   +-----------------------------------+---------+
   | iodef-EmailFrom                   | 132     |
   +-----------------------------------+---------+
   | iodef-EmailSubject                | 133     |
   +-----------------------------------+---------+
   | iodef-EmailX-Mailer               | 134     |
   +-----------------------------------+---------+
   | iodef-EmailHeaderField            | 135     |
   +-----------------------------------+---------+
   | iodef-EmailHeaders                | 136     |
   +-----------------------------------+---------+
   | iodef-EmailBody                   | 137     |
   +-----------------------------------+---------+
   | iodef-EmailMessage                | 138     |
   +-----------------------------------+---------+
   | iodef-HashData                    | 139     |
   +-----------------------------------+---------+
   | iodef-Signature                   | 140     |
   +-----------------------------------+---------+
   | iodef-RecordPattern               | 141     |
   +-----------------------------------+---------+
   | iodef-RecordItem                  | 142     |
   +-----------------------------------+---------+
   | iodef-FileData                    | 143     |
   +-----------------------------------+---------+
   | iodef-WindowsRegistryKeysModified | 144     |
   +-----------------------------------+---------+
   | iodef-CertificateData             | 145     |
   +-----------------------------------+---------+
   | iodef-offset                      | 146     |
   +-----------------------------------+---------+
   | iodef-offsetunit                  | 147     |
   +-----------------------------------+---------+
   | iodef-ext-offsetunit              | 148     |
   +-----------------------------------+---------+
   | iodef-Key                         | 149     |
   +-----------------------------------+---------+
   | iodef-registryaction              | 150     |
   +-----------------------------------+---------+
   | iodef-ext-registryaction          | 151     |
   +-----------------------------------+---------+
   | iodef-KeyName                     | 152     |
   +-----------------------------------+---------+
   | iodef-KeyValue                    | 153     |
   +-----------------------------------+---------+
   | iodef-Certificate                 | 154     |
   +-----------------------------------+---------+
   | iodef-X509Data                    | 155     |
   +-----------------------------------+---------+
   | iodef-File                        | 156     |
   +-----------------------------------+---------+
   | iodef-FileName                    | 157     |
   +-----------------------------------+---------+
   | iodef-FileSize                    | 158     |
   +-----------------------------------+---------+
   | iodef-FileType                    | 159     |
   +-----------------------------------+---------+
   | iodef-AssociatedSoftware          | 160     |
   +-----------------------------------+---------+
   | iodef-FileProperties              | 161     |
   +-----------------------------------+---------+
   | iodef-scope                       | 162     |
   +-----------------------------------+---------+
   | iodef-HashTargetID                | 163     |
   +-----------------------------------+---------+
   | iodef-Hash                        | 164     |
   +-----------------------------------+---------+
   | iodef-FuzzyHash                   | 165     |
   +-----------------------------------+---------+
   | iodef-DigestMethod                | 166     |
   +-----------------------------------+---------+
   | iodef-DigestValue                 | 167     |
   +-----------------------------------+---------+
   | iodef-CanonicalizationMethod      | 168     |
   +-----------------------------------+---------+
   | iodef-FuzzyHashValue              | 169     |
   +-----------------------------------+---------+
   | iodef-AlternativeIndicatorID      | 170     |
   +-----------------------------------+---------+
   | iodef-Observable                  | 171     |
   +-----------------------------------+---------+
   | iodef-uid-ref                     | 172     |
   +-----------------------------------+---------+
   | iodef-IndicatorExpression         | 173     |
   +-----------------------------------+---------+
   | iodef-IndicatorReference          | 174     |
   +-----------------------------------+---------+
   | iodef-AttackPhase                 | 175     |
   +-----------------------------------+---------+
   | iodef-BulkObservable              | 176     |
   +-----------------------------------+---------+
   | iodef-BulkObservableFormat        | 177     |
   +-----------------------------------+---------+
   | iodef-BulkObservableList          | 178     |
   +-----------------------------------+---------+
   | iodef-operator                    | 179     |
   +-----------------------------------+---------+
   | iodef-ext-operator                | 180     |
   +-----------------------------------+---------+
   | iodef-euid-ref                    | 181     |
   +-----------------------------------+---------+
   | iodef-AttackPhaseID               | 182     |
   +-----------------------------------+---------+

                   Table 4: Mapkeys

6.  The IODEF Data Model (CDDL)

   This section provides the IODEF data model.  Note that mapkeys are
   described at the beginning of the CDDL data model for better
   readability.

   start = iodef

   ;;; iodef.json: IODEF-Document

   iodef-version = -24
   iodef-lang = -23
   iodef-format-id = -22
   iodef-private-enum-name = -21
   iodef-private-enum-id = -20
   iodef-Incident = -19
   iodef-AdditionalData = -18
   iodef-value = -17
   iodef-translation-id = -16
   iodef-name = -15
   iodef-dtype = -14
   iodef-ext-dtype = -13
   iodef-meaning = -12
   iodef-formatid = -11
   iodef-restriction = -10
   iodef-ext-restriction = -9
   iodef-observable-id = -8
   iodef-SoftwareReference = -7
   iodef-URL = -6
   iodef-Description = -5
   iodef-spec-name = -4
   iodef-ext-spec-name = -3
   iodef-purpose = -2
   iodef-ext-purpose = -1
   iodef-status = 0
   iodef-ext-status = 1
   iodef-IncidentID = 2
   iodef-AlternativeID = 3
   iodef-RelatedActivity = 4
   iodef-DetectTime = 5
   iodef-StartTime = 6
   iodef-EndTime = 7
   iodef-RecoveryTime = 8
   iodef-ReportTime = 9
   iodef-GenerationTime = 10
   iodef-Discovery = 11
   iodef-Assessment = 12
   iodef-Method = 13
   iodef-Contact = 14
   iodef-EventData = 15
   iodef-Indicator = 16
   iodef-History = 17
   iodef-id = 18
   iodef-instance = 19
   iodef-ThreatActor = 20
   iodef-Campaign = 21
   iodef-IndicatorID = 22
   iodef-Confidence = 23
   iodef-ThreatActorID = 24
   iodef-CampaignID = 25
   iodef-role = 26
   iodef-ext-role = 27
   iodef-type = 28
   iodef-ext-type = 29
   iodef-ContactName = 30
   iodef-ContactTitle = 31
   iodef-RegistryHandle = 32
   iodef-PostalAddress = 33
   iodef-Email = 34
   iodef-Telephone = 35
   iodef-Timezone = 36
   iodef-handle = 37
   iodef-registry = 38
   iodef-ext-registry = 39
   iodef-PAddress = 40
   iodef-EmailTo = 41
   iodef-TelephoneNumber = 42
   iodef-source = 43
   iodef-ext-source = 44
   iodef-DetectionPattern = 45
   iodef-DetectionConfiguration = 46
   iodef-Application = 47
   iodef-Reference = 48
   iodef-AttackPattern = 49
   iodef-Vulnerability = 50
   iodef-Weakness = 51
   iodef-SpecID = 52
   iodef-ext-SpecID = 53
   iodef-ContentID = 54
   iodef-RawData = 55
   iodef-Platform = 56
   iodef-Scoring = 57
   iodef-ReferenceName = 58
   iodef-specIndex = 59
   iodef-ID = 60
   iodef-occurrence = 61
   iodef-IncidentCategory = 62
   iodef-Impact = 63
   iodef-SystemImpact = 64
   iodef-BusinessImpact = 65
   iodef-TimeImpact = 66
   iodef-MonetaryImpact = 67
   iodef-IntendedImpact = 68
   iodef-Counter = 69
   iodef-MitigatingFactor = 70
   iodef-Cause = 71
   iodef-severity = 72
   iodef-completion = 73
   iodef-ext-severity = 74
   iodef-metric = 75
   iodef-ext-metric = 76
   iodef-duration = 77
   iodef-ext-duration = 78
   iodef-currency = 79
   iodef-rating = 80
   iodef-ext-rating = 81
   iodef-HistoryItem = 82
   iodef-action = 83
   iodef-ext-action = 84
   iodef-DateTime = 85
   iodef-DefinedCOA = 86
   iodef-System = 87
   iodef-Expectation = 88
   iodef-RecordData = 89
   iodef-category = 90
   iodef-ext-category = 91
   iodef-interface = 92
   iodef-spoofed = 93
   iodef-virtual = 94
   iodef-ownership = 95
   iodef-ext-ownership = 96
   iodef-Node = 97
   iodef-NodeRole = 98
   iodef-Service = 99
   iodef-OperatingSystem = 100
   iodef-AssetID = 101
   iodef-DomainData = 102
   iodef-Address = 103
   iodef-Location = 104
   iodef-vlan-name = 105
   iodef-vlan-num = 106
   iodef-unit = 107
   iodef-ext-unit = 108
   iodef-system-status = 109
   iodef-ext-system-status = 110
   iodef-domain-status = 111
   iodef-ext-domain-status = 112
   iodef-Name = 113
   iodef-DateDomainWasChecked = 114
   iodef-RegistrationDate = 115
   iodef-ExpirationDate = 116
   iodef-RelatedDNS = 117
   iodef-NameServers = 118
   iodef-DomainContacts = 119
   iodef-Server = 120
   iodef-SameDomainContact = 121
   iodef-ip-protocol = 122
   iodef-ServiceName = 123
   iodef-Port = 124
   iodef-Portlist = 125
   iodef-ProtoCode = 126
   iodef-ProtoType = 127
   iodef-ProtoField = 128
   iodef-ApplicationHeaderField = 129
   iodef-EmailData = 130
   iodef-IANAService = 131
   iodef-EmailFrom = 132
   iodef-EmailSubject = 133
   iodef-EmailX-Mailer = 134
   iodef-EmailHeaderField = 135
   iodef-EmailHeaders = 136
   iodef-EmailBody = 137
   iodef-EmailMessage = 138
   iodef-HashData = 139
   iodef-Signature = 140
   iodef-RecordPattern = 141
   iodef-RecordItem = 142
   iodef-FileData = 143
   iodef-WindowsRegistryKeysModified = 144
   iodef-CertificateData = 145
   iodef-offset = 146
   iodef-offsetunit = 147
   iodef-ext-offsetunit = 148
   iodef-Key = 149
   iodef-registryaction = 150
   iodef-ext-registryaction = 151
   iodef-KeyName = 152
   iodef-KeyValue = 153
   iodef-Certificate = 154
   iodef-X509Data = 155
   iodef-File = 156
   iodef-FileName = 157
   iodef-FileSize = 158
   iodef-FileType = 159
   iodef-AssociatedSoftware = 160
   iodef-FileProperties = 161
   iodef-scope = 162
   iodef-HashTargetID = 163
   iodef-Hash = 164
   iodef-FuzzyHash = 165
   iodef-DigestMethod = 166
   iodef-DigestValue = 167
   iodef-CanonicalizationMethod = 168
   iodef-FuzzyHashValue = 169
   iodef-AlternativeIndicatorID = 170
   iodef-Observable = 171
   iodef-uid-ref = 172
   iodef-IndicatorExpression = 173
   iodef-IndicatorReference = 174
   iodef-AttackPhase = 175
   iodef-BulkObservable = 176
   iodef-BulkObservableFormat = 177
   iodef-BulkObservableList = 178
   iodef-operator = 179
   iodef-ext-operator = 180
   iodef-euid-ref = 181
   iodef-AttackPhaseID = 182

   iodef = {
    iodef-version => text,
    ? iodef-lang => lang,
    ? iodef-format-id => text
    ? iodef-private-enum-name => text,
    ? iodef-private-enum-id => text,
    iodef-Incident => [+ Incident],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   duration = "second" / "minute" / "hour" / "day" / "month" /
   "quarter" / "year" / "ext-value"
   lang = "" / text .regexp "[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*"

   restriction = "public" / "partner" / "need-to-know" / "private" /
   "default" / "white" / "green" / "amber" / "red" /
   "ext-value"
   SpecID = "urn:ietf:params:xml:ns:mile:mmdef:1.2" /  "private"
   IDtype = text .regexp "[a-zA-Z_][a-zA-Z0-9_.-]*"
   IDREFType = IDtype
   URLtype = uri
   TimeZonetype = text .regexp "Z|[\\+\\-](0[0-9]|1[0-4]):[0-5][0-9]"
   PortlistType = text .regexp
                           "[0-9]+(\\-[0-9]+)?(,[0-9]+(\\-[0-9]+)?)*"
   action = "nothing" / "contact-source-site" / "contact-target-site" /
   "contact-sender" / "investigate" / "block-host" /
   "block-network" / "block-port" / "rate-limit-host" /
   "rate-limit-network" / "rate-limit-port" / "redirect-traffic" /
   "honeypot" / "upgrade-software" / "rebuild-asset" /
   "harden-asset" / "remediate-other" / "status-triage" /
   "status-new-info" / "watch-and-report" / "training" /
   "defined-coa" / "other" / "ext-value"

   DATETIME = tdate

   BYTE = eb64legacy

   MLStringType = {
       iodef-value => text,
       ? iodef-lang => lang,
       ? iodef-translation-id => text
   } / text

   PositiveFloatType = float32 .gt 0

   PAddressType = MLStringType

   ExtensionType  = {
    iodef-value => text,
    ? iodef-name => text,
    iodef-dtype => "boolean" / "byte" / "bytes" / "character" /
   "date-time" / "ntpstamp" / "integer" / "portlist" / "real" /
   "string" / "file" / "path" / "frame" / "packet" / "ipv4-packet" /
   "json" / "ipv6-packet" / "url" / "csv" / "winreg" / "xml" /
   "ext-value"
   .default "string"
    ? iodef-ext-dtype => text,
    ? iodef-meaning => text,
    ? iodef-formatid => text,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
   }

   SoftwareType = {
    ? iodef-SoftwareReference => SoftwareReference,
    ? iodef-URL => [+ URLtype],
    ? iodef-Description => [+ MLStringType]
   }

   SoftwareReference = {
    ? iodef-value => text,
    iodef-spec-name => "custom" / "cpe" / "swid" / "ext-value",
    ? iodef-ext-spec-name => text,
    ? iodef-dtype => "bytes" / "integer" / "real" / "string" / "xml" /
   "ext-value" .default "string",
    ? iodef-ext-dtype => text
   }

   Incident = {
    iodef-purpose => "traceback" / "mitigation" / "reporting" /
   "watch" / "other" / "ext-value",
    ? iodef-ext-purpose => text,
    ? iodef-status => "new" / "in-progress"/ "forwarded" / "resolved" /
   "future" / "ext-value",
    ? iodef-ext-status => text,
    ? iodef-lang => lang,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    iodef-IncidentID => IncidentID,
    ? iodef-AlternativeID => AlternativeID,
    ? iodef-RelatedActivity => [+ RelatedActivity],
    ? iodef-DetectTime => DATETIME,
    ? iodef-StartTime => DATETIME,
    ? iodef-EndTime => DATETIME,
    ? iodef-RecoveryTime => DATETIME,
    ? iodef-ReportTime => DATETIME,
    iodef-GenerationTime => DATETIME,
    ? iodef-Description => [+ MLStringType],
    ? iodef-Discovery => [+ Discovery],
    ? iodef-Assessment => [+ Assessment],
    ? iodef-Method => [+ Method],
    iodef-Contact => [+ Contact],
    ? iodef-EventData => [+ EventData],
    ? iodef-Indicator => [+ Indicator],
    ? iodef-History => History,
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   IncidentID = {
    iodef-id => text,
    iodef-name => text,
    ? iodef-instance => text,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text
   }

   AlternativeID = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    iodef-IncidentID => [+ IncidentID]
   }

   RelatedActivity = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-IncidentID => [+ IncidentID],
    ? iodef-URL => [+ URLtype],
    ? iodef-ThreatActor => [+ ThreatActor],
    ? iodef-Campaign => [+ Campaign],
    ? iodef-IndicatorID => [+ IndicatorID],
    ? iodef-Confidence => Confidence,
    ? iodef-Description => [+ text],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   ThreatActor = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-ThreatActorID => [+ text],
    ? iodef-URL => [+ URLtype],
    ? iodef-Description => [+ MLStringType],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   Campaign  = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-CampaignID => [+ text],
    ? iodef-URL => [+ URLtype],
    ? iodef-Description => [+ MLStringType],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   Contact = {
    iodef-role => "creator" / "reporter" / "admin" / "tech" /
   "provider" / "user" / "billing" / "legal" / "irt" / "abuse" /
   "cc" / "cc-irt" / "leo" / "vendor" / "vendor-support" /
   "victim" / "victim-notified" / "ext-value",
    ? iodef-ext-role => text,
    iodef-type => "person" / "organization" / "ext-value",
    ? iodef-ext-type => text,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-ContactName => [+ MLStringType],
    ? iodef-ContactTitle => [+ MLStringType],
    ? iodef-Description => [+ MLStringType],
    ? iodef-RegistryHandle => [+ RegistryHandle],
    ? iodef-PostalAddress => [+ PostalAddress],
    ? iodef-Email => [+ Email],
    ? iodef-Telephone => [+ Telephone],
    ? iodef-Timezone => TimeZonetype,
    ? iodef-Contact => [+ Contact],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   RegistryHandle = {
    iodef-handle => text,
    iodef-registry => "internic" / "apnic" / "arin" / "lacnic" /
   "ripe" / "afrinic" / "local" / "ext-value",
    ? iodef-ext-registry => text
   }

   PostalAddress = {
    ? iodef-type => "street" / "mailing" / "ext-value",
    ? iodef-ext-type => text,
    iodef-PAddress => PAddressType,
    ? iodef-Description => [+ MLStringType]
   }

   Email = {
    ? iodef-type => "direct" / "hotline" / "ext-value",
    ? iodef-ext-type => text,
    iodef-EmailTo => text,
    ? iodef-Description => [+ MLStringType]
   }

   Telephone = {
    ? iodef-type => "wired" / "mobile" / "fax" / "hotline" /
    "ext-value",
    ? iodef-ext-type => text,
    iodef-TelephoneNumber => text,
    ? iodef-Description => [+ MLStringType]
   }

   Discovery = {
    ? iodef-source => "nidps" / "hips" / "siem" / "av" /
   "third-party-monitoring" / "incident" / "os-log" /
   "application-log" / "device-log" / "network-flow" /
   "passive-dns" / "investigation" / "audit" /
   "internal-notification" / "external-notification" /
   "leo" / "partner" / "actor" / "unknown" / "ext-value",
    ? iodef-ext-source => text,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-Description => [+ MLStringType],
    ? iodef-Contact => [+ Contact],
    ? iodef-DetectionPattern => [+ DetectionPattern]
   }

   DetectionPattern = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    (iodef-Description => [+ MLStringType] //
                  iodef-DetectionConfiguration => [+ text]),
    iodef-Application => SoftwareType
   }

   Method = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-Reference => [+ Reference],
    ? iodef-Description => [+ MLStringType],
    ? iodef-AttackPattern => [+ STRUCTUREDINFO],
    ? iodef-Vulnerability => [+ STRUCTUREDINFO],
    ? iodef-Weakness => [+ STRUCTUREDINFO],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   STRUCTUREDINFO = {
    iodef-SpecID => SpecID,
    ? iodef-ext-SpecID => text,
    ? iodef-ContentID => text,
    ? (iodef-RawData => [+ BYTE] // iodef-Reference => [+ Reference]),
    ? iodef-Platform => [+ Platform],
    ? iodef-Scoring => [+ Scoring]
   }

   Platform = {
       iodef-SpecID => SpecID,
       ? iodef-ext-SpecID => text,
       ? iodef-ContentID => text,
       ? iodef-RawData => [+ BYTE],
       ? iodef-Reference => [+ Reference]
   }
   Scoring = {
       iodef-SpecID => SpecID,
       ? iodef-ext-SpecID => text,
       ? iodef-ContentID => text,
       ? iodef-RawData => [+ BYTE],
       ? iodef-Reference => [+ Reference]
   }
   Reference = {
    ? iodef-observable-id => IDtype,
    ? iodef-ReferenceName => ReferenceName,
    ? iodef-URL => [+ URLtype],
    ? iodef-Description => [+ MLStringType]
   }

   ReferenceName = {
    iodef-specIndex => integer,
    iodef-ID => IDtype
   }

   Assessment = {
    ? iodef-occurrence => "actual" / "potential",
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    ? iodef-IncidentCategory => [+ MLStringType],
    iodef-Impact => [+ {iodef-SystemImpact => SystemImpact} /
             {iodef-BusinessImpact => BusinessImpact /
             {iodef-TimeImpact => TimeImpact} /
             {iodef-MonetaryImpact => MonetaryImpact} /
             {iodef-IntendedImpact => BusinessImpact}],
    ? iodef-Counter => [+ Counter],
    ? iodef-MitigatingFactor => [+ MLStringType],
    ? iodef-Cause => [+ MLStringType],
    ? iodef-Confidence => Confidence,
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   SystemImpact = {
    ? iodef-severity => "low" / "medium" / "high",
    ? iodef-completion => "failed" / "succeeded",
    iodef-type => "takeover-account" / "takeover-service" /
   "takeover-system" / "cps-manipulation" / "cps-damage" /
   "availability-data" / "availability-account" /
   "availability-service" / "availability-system" / "damaged-system" /
   "damaged-data" / "breach-proprietary" / "breach-privacy" /
   "breach-credential" / "breach-configuration" / "integrity-data" /
   "integrity-configuration" / "integrity-hardware" /
   "traffic-redirection" / "monitoring-traffic" / "monitoring-host" /
   "policy" / "unknown" / "ext-value" .default "unknown",
    ? iodef-ext-type => text,
    ? iodef-Description => [+ MLStringType]
   }

   BusinessImpact = {
   ? iodef-severity => "none" / "low" / "medium" / "high" / "unknown" /
   "ext-value" .default "unknown",
    ? iodef-ext-severity => text,
    iodef-type => "breach-proprietary" / "breach-privacy" /
   "breach-credential" / "loss-of-integrity" / "loss-of-service" /
   "theft-financial" / "theft-service" / "degraded-reputation" /
   "asset-damage" / "asset-manipulation" / "legal" / "extortion" /
   "unknown" / "ext-value" .default "unknown",
    ? iodef-ext-type => text,
    ? iodef-Description => [+ MLStringType]
   }

   TimeImpact = {
    iodef-value => PositiveFloatType,
    ? iodef-severity => "low" / "medium" / "high",
    iodef-metric => "labor" / "elapsed" / "downtime" / "ext-value",
    ? iodef-ext-metric => text,
    ? iodef-duration => duration .default "hour",
    ? iodef-ext-duration => text
   }

   MonetaryImpact = {
    iodef-value => PositiveFloatType,
    ? iodef-severity => "low" / "medium" / "high",
    ? iodef-currency => text
   }

   Confidence = {
    iodef-value => float32,
    iodef-rating => "low" / "medium" / "high" / "numeric" / "unknown" /
   "ext-value",
    ? iodef-ext-rating => text
   }

   History = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    iodef-HistoryItem => [+ HistoryItem]
   }

   HistoryItem = {
    iodef-action => action .default "other",
    ? iodef-ext-action => text,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    iodef-DateTime => DATETIME,
    ? iodef-IncidentID => IncidentID,
    ? iodef-Contact => Contact,
    ? iodef-Description => [+ MLStringType],
    ? iodef-DefinedCOA => [+ text],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   EventData = {
    ? iodef-restriction => restriction .default "default",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    ? iodef-Description => [+ MLStringType],
    ? iodef-DetectTime => DATETIME,
    ? iodef-StartTime => DATETIME,
    ? iodef-EndTime => DATETIME,
    ? iodef-RecoveryTime => DATETIME,
    ? iodef-ReportTime => DATETIME,
    ? iodef-Contact => [+ Contact],
    ? iodef-Discovery => [+ Discovery],
    ? iodef-Assessment => Assessment,
    ? iodef-Method => [+ Method],
    ? iodef-System => [+ System],
    ? iodef-Expectation => [+ Expectation],
    ? iodef-RecordData => [+ RecordData],
    ? iodef-EventData => [+ EventData],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   Expectation = {
    ? iodef-action => action .default "other",
    ? iodef-ext-action => text,
    ? iodef-severity => "low" / "medium" / "high",
    ? iodef-restriction => restriction .default "default",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    ? iodef-Description => [+ MLStringType],
    ? iodef-DefinedCOA => [+ text],
    ? iodef-StartTime => DATETIME,
    ? iodef-EndTime => DATETIME,
    ? iodef-Contact => Contact
   }

   System = {
    ? iodef-category => "source" / "target" / "intermediate" /
   "sensor" / "infrastructure" / "ext-value",
    ? iodef-ext-category => text,
    ? iodef-interface => text,
    ? iodef-spoofed => "unknown" / "yes" / "no" .default "unknown",
    ? iodef-virtual => "yes" / "no" / "unknown" .default "unknown",
    ? iodef-ownership => "organization" / "personal" / "partner" /
   "customer" / "no-relationship" / "unknown" / "ext-value",
    ? iodef-ext-ownership => text,
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    iodef-Node => Node,
    ? iodef-NodeRole => [+ NodeRole],
    ? iodef-Service => [+ Service],
    ? iodef-OperatingSystem => [+ SoftwareType],
    ? iodef-Counter => [+ Counter],
    ? iodef-AssetID => [+ text],
    ? iodef-Description => [+ MLStringType],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   Node = {
    (iodef-DomainData => [+ DomainData] //
                                  iodef-Address => [+ Address]),
    ? iodef-PostalAddress => PostalAddress,
    ? iodef-Location => [+ MLStringType],
    ? iodef-Counter => [+ Counter]
   }

   Address = {
    iodef-value => text,
    iodef-category => "asn" / "atm" / "e-mail" / "ipv4-addr" /
   "ipv4-net" / "ipv4-net-masked" / "ipv4-net-mask" / "ipv6-addr" /
   "ipv6-net" / "ipv6-net-masked" / "mac" / "site-uri" /
   "ext-value" .default "ipv6-addr",
    ? iodef-ext-category => text,
    ? iodef-vlan-name => text,
    ? iodef-vlan-num => integer,
    ? iodef-observable-id => IDtype
   }

   NodeRole = {
    iodef-category => "client" / "client-enterprise" /
   "client-partner" / "client-remote" / "client-kiosk" /
   "client-mobile" / "server-internal" / "server-public" /
   "www" / "mail" / "webmail" / "messaging" / "streaming" /
   "voice" / "file" / "ftp" / "p2p" / "name" / "directory" /
   "credential" / "print" / "application" / "database" /
   "backup" / "dhcp" / "assessment" / "source-control" /
   "config-management" / "monitoring" / "infra" / "infra-firewall" /
   "infra-router" / "infra-switch" / "camera" / "proxy" /
   "remote-access" / "log" / "virtualization" / "pos" /  "scada" /
   "scada-supervisory" / "sinkhole" / "honeypot" /
   "anomyzation" / "c2-server" / "malware-distribution" /
   "drop-server" / "hop-point" / "reflector" /
   "phishing-site" / "spear-phishing-site" / "recruiting-site" /
   "fraudulent-site" / "ext-value",
    ? iodef-ext-category => text,
    ? iodef-Description => [+ MLStringType]
   }

   Counter = {
    iodef-value => float32,
    iodef-type => "count" / "peak" / "average" / "ext-value",
    ? iodef-ext-type => text,
    iodef-unit => "byte" / "mbit" / "packet" / "flow" / "session" /
   "alert" / "message" / "event" / "host" / "site" / "organization" /
   "ext-value",
    ? iodef-ext-unit => text,
    ? iodef-meaning => text,
    ? iodef-duration => duration .default "hour",
    ? iodef-ext-duration => text
   }

   DomainData = {
    iodef-system-status => "spoofed" / "fraudulent" /
   "innocent-hacked" / "innocent-hijacked" / "unknown" / "ext-value",
    ? iodef-ext-system-status => text,
    iodef-domain-status => "reservedDelegation" / "assignedAndActive" /
   "assignedAndInactive" / "assignedAndOnHold" /
   "revoked" / "transferPending" / "registryLock" /
   "registrarLock" / "other" / "unknown" / "ext-value",
    ? iodef-ext-domain-status => text,
    ? iodef-observable-id => IDtype,
    iodef-Name => text,
    ? iodef-DateDomainWasChecked => DATETIME,
    ? iodef-RegistrationDate => DATETIME,
    ? iodef-ExpirationDate => DATETIME,
    ? iodef-RelatedDNS => [+ ExtensionType],
    ? iodef-NameServers => [+ NameServers],
    ? iodef-DomainContacts => DomainContacts
   }

   NameServers = {
    iodef-Server => text,
    iodef-Address => [+ Address]
   }

   DomainContacts = {
    (iodef-SameDomainContact => text // iodef-Contact => [+ Contact])
   }

   Service = {
    ? iodef-ip-protocol => integer,
    ? iodef-observable-id => IDtype,
    ? iodef-ServiceName => ServiceName,
    ? iodef-Port => integer,
    ? iodef-Portlist => PortlistType,
    ? iodef-ProtoCode => integer,
    ? iodef-ProtoType => integer,
    ? iodef-ProtoField => integer,
    ? iodef-ApplicationHeaderField => [+ ExtensionType],
    ? iodef-EmailData => EmailData,
    ? iodef-Application => SoftwareType
   }

   ServiceName = {
    ? iodef-IANAService => text,
    ? iodef-URL => [+ URLtype],
    ? iodef-Description => [+ MLStringType]
   }

   EmailData = {
    ? iodef-observable-id => IDtype,
    ? iodef-EmailTo => [+ text],
    ? iodef-EmailFrom => text,
    ? iodef-EmailSubject => text,
    ? iodef-EmailX-Mailer => text,
    ? iodef-EmailHeaderField => [+ ExtensionType],
    ? iodef-EmailHeaders => text,
    ? iodef-EmailBody => text,
    ? iodef-EmailMessage => text,
    ? iodef-HashData => [+ HashData],
    ? iodef-Signature => [+ BYTE]
   }

   RecordData = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    ? iodef-DateTime => DATETIME,
    ? iodef-Description => [+ MLStringType],
    ? iodef-Application => SoftwareType,
    ? iodef-RecordPattern => [+ RecordPattern],
    ? iodef-RecordItem => [+ ExtensionType],
    ? iodef-URL => [+ URLtype],
    ? iodef-FileData => [+ FileData],
    ? iodef-WindowsRegistryKeysModified =>
                                   [+ WindowsRegistryKeysModified],
    ? iodef-CertificateData => [+ CertificateData],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   RecordPattern = {
    iodef-value => text,
    iodef-type => "regex" / "binary" / "xpath" /
   "ext-value"  .default "regex",
    ? iodef-ext-type => text,
    ? iodef-offset => integer,
    ? iodef-offsetunit => "line" / "byte" /
   "ext-value" .default "line",
    ? iodef-ext-offsetunit => text,
    ? iodef-instance => integer
   }

   WindowsRegistryKeysModified = {
    ? iodef-observable-id => IDtype,
    iodef-Key => [+ Key]
   }

   Key = {
    ? iodef-registryaction => "add-key" / "add-value" / "delete-key" /
   "delete-value" / "modify-key" / "modify-value" /
   "ext-value",
    ? iodef-ext-registryaction => text,
    ? iodef-observable-id => IDtype,
    iodef-KeyName => text,
    ? iodef-KeyValue => text
   }

   CertificateData = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    iodef-Certificate => [+ Certificate]
   }

   Certificate = {
    ? iodef-observable-id => IDtype,
    iodef-X509Data => BYTE,
    ? iodef-Description => [+ MLStringType]
   }

   FileData = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? iodef-observable-id => IDtype,
    iodef-File => [+ File]
   }

   File = {
    ? iodef-observable-id => IDtype,
    ? iodef-FileName => text,
    ? iodef-FileSize => integer,
    ? iodef-FileType => text,
    ? iodef-URL => [+ URLtype],
    ? iodef-HashData => HashData,
    ? iodef-Signature => [+ BYTE],
    ? iodef-AssociatedSoftware => SoftwareType,
    ? iodef-FileProperties => [+ ExtensionType]
   }

   HashData = {
    iodef-scope => "file-contents" / "file-pe-section" /
   "file-pe-iat" / "file-pe-resource" / "file-pdf-object" /
   "email-hash" / "email-headers-hash" / "email-body-hash" /
   "ext-value",
    ? iodef-HashTargetID => text,
    ? iodef-Hash => [+ Hash],
    ? iodef-FuzzyHash => [+ FuzzyHash]
   }

   Hash = {
    iodef-DigestMethod => BYTE,
    iodef-DigestValue => BYTE,
    ? iodef-CanonicalizationMethod => BYTE,
    ? iodef-Application => SoftwareType
   }

   FuzzyHash = {
    iodef-FuzzyHashValue => [+ ExtensionType],
    ? iodef-Application => SoftwareType,
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   Indicator = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    iodef-IndicatorID => IndicatorID,
    ? iodef-AlternativeIndicatorID => [+ AlternativeIndicatorID],
    ? iodef-Description => [+ MLStringType],
    ? iodef-StartTime => DATETIME,
    ? iodef-EndTime => DATETIME,
    ? iodef-Confidence => Confidence,
    ? iodef-Contact => [+ Contact],
    (iodef-Observable => Observable // iodef-uid-ref => IDREFType //
     iodef-IndicatorExpression => IndicatorExpression //
     iodef-IndicatorReference => IndicatorReference),
    ? iodef-NodeRole => [+ NodeRole],
    ? iodef-AttackPhase => [+ AttackPhase],
    ? iodef-Reference => [+ Reference],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   IndicatorID = {
    iodef-id => IDtype,
    iodef-name => text,
    iodef-version => text
   }

   AlternativeIndicatorID = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    iodef-IndicatorID => [+ IndicatorID]
   }

   Observable = {
    ? iodef-restriction => restriction .default "private",
    ? iodef-ext-restriction => text,
    ? (iodef-System => System // iodef-Address => Address //
       iodef-DomainData => DomainData //
       iodef-EmailData => EmailData //
       iodef-Service => Service //
       iodef-WindowsRegistryKeysModified =>
                                     WindowsRegistryKeysModified //
       iodef-FileData => FileData //iodef-CertificateData =>
                                                 CertificateData //
       iodef-RegistryHandle =>RegistryHandle// iodef-RecordData =>
                                                     RecordData //
       iodef-EventData => EventData // iodef-Incident => Incident //
       iodef-Expectation => Expectation // iodef-Reference =>
                                                       Reference //
       iodef-Assessment => Assessment //
       iodef-DetectionPattern => DetectionPattern //
       iodef-HistoryItem => HistoryItem //
       iodef-BulkObservable => BulkObservable //
       iodef-AdditionalData => [+ ExtensionType])
   }

   BulkObservable = {
    ? iodef-type => "asn" / "atm" / "e-mail" / "ipv4-addr" /
   "ipv4-net" / "ipv4-net-mask" / "ipv6-addr" / "ipv6-net" /
   "ipv6-net-mask" / "mac" / "site-uri" / "domain-name" /
   "domain-to-ipv4" / "domain-to-ipv6" /
   "domain-to-ipv4-timestamp" / "domain-to-ipv6-timestamp" /
   "ipv4-port" / "ipv6-port" / "windows-reg-key" / "file-hash" /
   "email-x-mailer" / "email-subject" / "http-user-agent" /
   "http-request-uri" / "mutex" / "file-path" / "user-name" /
   "ext-value",
    ? iodef-ext-type => text,
    ? iodef-BulkObservableFormat => BulkObservableFormat,
    iodef-BulkObservableList => text,
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   BulkObservableFormat = {
    (iodef-Hash => Hash // iodef-AdditionalData => [+ ExtensionType])
   }

   IndicatorExpression = {
    ? iodef-operator => "not" / "and" / "or" / "xor" .default "and",
    ? iodef-ext-operator => text,
    ? iodef-IndicatorExpression => [+ IndicatorExpression],
    ? iodef-Observable => [+ Observable],
    ? iodef-uid-ref => [+ IDREFType],
    ? iodef-IndicatorReference => [+ IndicatorReference],
    ? iodef-Confidence => Confidence,
    ? iodef-AdditionalData => [+ ExtensionType]
   }

   IndicatorReference = {
    (iodef-uid-ref => IDREFType // iodef-euid-ref => text),
    ? iodef-version => text
   }

   AttackPhase = {
    ? iodef-AttackPhaseID => [+ text],
    ? iodef-URL => [+ URLtype],
    ? iodef-Description => [+ MLStringType],
    ? iodef-AdditionalData => [+ ExtensionType]
   }

                        Figure 5: Data Model in CDDL

7.  IANA Considerations

   This document has no IANA actions.

8.  Security Considerations

   This document provides a mapping from XML IODEF defined in [RFC7970]
   to JSON, and Section 3.2 describes several issues that arise when
   converting XML IODEF and JSON IODEF.  Though it does not provide any
   further security considerations other than the one described in
   [RFC7970], implementers of this document should be aware of those
   issues to avoid any unintended outcome.

9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
              <https://www.rfc-editor.org/info/rfc4648>.

   [RFC7049]  Bormann, C. and P. Hoffman, "Concise Binary Object
              Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
              October 2013, <https://www.rfc-editor.org/info/rfc7049>.

   [RFC7203]  Takahashi, T., Landfield, K., and Y. Kadobayashi, "An
              Incident Object Description Exchange Format (IODEF)
              Extension for Structured Cybersecurity Information",
              RFC 7203, DOI 10.17487/RFC7203, April 2014,
              <https://www.rfc-editor.org/info/rfc7203>.

   [RFC7970]  Danyliw, R., "The Incident Object Description Exchange
              Format Version 2", RFC 7970, DOI 10.17487/RFC7970,
              November 2016, <https://www.rfc-editor.org/info/rfc7970>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/info/rfc8259>.

   [RFC8610]  Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
              Definition Language (CDDL): A Notational Convention to
              Express Concise Binary Object Representation (CBOR) and
              JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
              June 2019, <https://www.rfc-editor.org/info/rfc8610>.

9.2.  Informative References

   [JSON-SCHEMA]
              Wright, A., Andrews, H., and B. Hutton, "JSON Schema
              Validation: A Vocabulary for Structural Validation of
              JSON", Work in Progress, Internet-Draft, draft-handrews-
              json-schema-validation-02, 17 September 2019,
              <https://tools.ietf.org/html/draft-handrews-json-schema-
              validation-02>.

Appendix A.  Data Types Used in This Document

   The CDDL prelude used in this document is mapped to JSON as shown in
   the table below.

   +==============+=========+==========+=============================+
   | CDDL Prelude | Use of  | Instance | Validation                  |
   |              | JSON    |          |                             |
   +==============+=========+==========+=============================+
   | bytes        | n/a     | string   | tool available              |
   +--------------+---------+----------+-----------------------------+
   | text         | string  | string   | unnecessary                 |
   +--------------+---------+----------+-----------------------------+
   | tdate        | n/a     | string   | date-time per Section 7.3.1 |
   |              |         |          | of [JSON-SCHEMA]            |
   +--------------+---------+----------+-----------------------------+
   | integer      | n/a     | number   | integer                     |
   +--------------+---------+----------+-----------------------------+
   | eb64legacy   | n/a     | string   | tool available              |
   +--------------+---------+----------+-----------------------------+
   | uri          | n/a     | string   | uri per Section 7.3.6 of    |
   |              |         |          | [JSON-SCHEMA]               |
   +--------------+---------+----------+-----------------------------+
   | float32      | float32 | number   | unnecessary                 |
   +--------------+---------+----------+-----------------------------+

                  Table 5: CDDL Prelude Mapping in JSON

Appendix B.  The IODEF Data Model (JSON Schema)

   This section provides a JSON schema [JSON-SCHEMA] that defines the
   IODEF data model defined in this document.  Note that this section is
   informative.

   { "$schema": "https://json-schema.org/draft-04/schema#",
     "definitions": {
       "action": {"enum": ["nothing", "contact-source-site",
          "contact-target-site", "contact-sender", "investigate",
          "block-host", "block-network", "block-port",
          "rate-limit-host", "rate-limit-network",
          "rate-limit-port", "redirect-traffic", "honeypot",
          "upgrade-software", "rebuild-asset", "harden-asset",
          "remediate-other", "status-triage", "status-new-info",
          "watch-and-report", "training", "defined-coa", "other",
          "ext-value"]},
       "duration":{"enum":["second", "minute", "hour", "day",
         "month", "quarter", "year", "ext-value"]},
       "SpecID":{
         "enum":["urn:ietf:params:xml:ns:mile:mmdef:1.2",
          "private"]},
       "lang": {
         "type":"string", "pattern":
           "^$|[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*"},
       "purpose": {"enum": ["traceback", "mitigation",
         "reporting", "watch", "other", "ext-value"]},
       "restriction":{"enum": ["public", "partner",
         "need-to-know", "private", "default", "white", "green",
         "amber", "red", "ext-value"]},
       "status": {"enum": ["new", "in-progress", "forwarded",
         "resolved", "future", "ext-value"]},
       "DATETIME": {"type": "string", "format": "date-time"},
       "BYTE": {"type": "string"},
       "PortlistType": {
         "type": "string", "pattern":
           "[0-9]+(\\-[0-9]+)?(,[0-9]+(\\-[0-9]+)?)*"},
       "TimeZonetype": {
         "type":"string", "pattern":
           "Z|[\\+\\-](0[0-9]|1[0-4]):[0-5][0-9]"},
       "URLtype": {
         "type": "string",
         "pattern":
           "^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\\?([^#]*))
             ?(#(.*))?"},
       "IDtype": {"type": "string", "pattern":
         "[a-zA-Z_][a-zA-Z0-9_.-]*"},
       "IDREFType": {"$ref": "#/definitions/IDtype"},
       "MLStringType": {
         "oneOf": [{"type": "string"},
                   {"type": "object",
                     "properties": {
                       "value": {"type": "string"},
                       "lang": {"$ref": "#/definitions/lang"},
                       "translation-id": {"type": "string"}},
                      "required": ["value"],
                      "additionalProperties":false}]},
       "PositiveFloatType": {"type": "number", "minimum": 0},
       "PAddressType": {"$ref": "#/definitions/MLStringType"},
       "ExtensionType": {
         "type": "object",
         "properties": {
           "value": {"type": "string"},
           "name": {"type": "string"},
           "dtype":{"enum":["boolean", "byte", "bytes",
             "character", "json", "date-time", "ntpstamp",
             "integer", "portlist", "real", "string", "file",
             "path", "frame", "packet", "ipv4-packet",
             "ipv6-packet", "url", "csv", "winreg",
             "xml", "ext-value"], "default": "string"},
           "ext-dtype": {"type": "string"},
           "meaning": {"type": "string"},
           "formatid": {"type": "string"},
           "restriction": {
             "$ref": "#/definitions/restriction", "default":
               "private"},
           "ext-restriction": {"type": "string"},
           "observable-id": {"$ref": "#/definitions/IDtype"}},
         "required": ["value", "dtype"],
         "additionalProperties":false},
       "ExtensionTypeList": {
         "type": "array",
         "items": {"$ref": "#/definitions/ExtensionType"},
         "minItems": 1},
       "SoftwareType": {
         "type": "object",
         "properties": {
           "SoftwareReference":{
             "$ref":"#/definitions/SoftwareReference"},
           "URL": {
             "type": "array",
             "items": {"$ref": "#/definitions/URLtype",
             "minItems": 1}},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1 }},
         "required": [],
         "additionalProperties": false},
       "SoftwareReference": {
         "type": "object",
         "properties": {
           "value": {"type": "string"},
           "spec-name": {"enum": ["custom", "cpe", "swid",
             "ext-value"]},
           "ext-spec-name": {"type": "string"},
           "dtype": {"enum": ["bytes", "integer", "real", "string",
             "xml", "ext-value"], "default": "string"},
           "ext-dtype": {"type": "string"}},
         "required": ["spec-name"],
         "additionalProperties": false},
       "STRUCTUREDINFO": {
         "type": "object",
         "properties": {
           "SpecID": {"$ref":"#/definitions/SpecID"},
           "ext-SpecID": {"type": "string"},
           "ContentID": {"type": "string"},
           "RawData": {
              "type": "array",
              "items": {"$ref":"#/definitions/BYTE"},
              "minItems": 1
           },
           "Reference": {
             "type": "array",
             "items": {"$ref": "#/definitions/Reference"},
             "minItems": 1
           },
           "Platform": {
             "type": "array",
             "items": {"$ref": "#/definitions/Platform"},
             "minItems": 1
           },
           "Scoring": {
             "type": "array",
             "items": {"$ref": "#/definitions/Scoring"},
             "minItems": 1}},
         "allOf": [
            {"required": ["SpecID"]},
            {"anyOf": [
              {"oneOf": [
                {"required":["Reference"]},
                {"required":["RawData"]}]},
              { "not" : {"required":["Reference", "RawData"]}}]}],
         "additionalProperties": false},
       "Platform": {
         "type": "object",
         "properties": {
           "SpecID": {"$ref":"#/definitions/SpecID"},
           "ext-SpecID": {"type": "string"},
           "ContentID": {"type": "string"},
           "RawData": {
              "type": "array",
              "items": {"$ref":"#/definitions/BYTE"},
              "minItems": 1
           },
           "Reference": {
             "type": "array",
             "items": {"$ref": "#/definitions/Reference"},
             "minItems": 1}},
         "required": ["SpecID"],
         "additionalProperties": false},
       "Scoring": {
         "type": "object",
         "properties": {
           "SpecID": {"$ref":"#/definitions/SpecID"},
           "ext-SpecID": {"type": "string"},
           "ContentID": {"type": "string"},
           "RawData": {
              "type": "array",
              "items": {"$ref":"#/definitions/BYTE"},
              "minItems": 1
           },
           "Reference": {
             "type": "array",
             "items": {"$ref": "#/definitions/Reference"},
             "minItems": 1}},
         "required": ["SpecID"],
         "additionalProperties": false},
       "Incident": {
         "title": "Incident",
         "description": "JSON schema for Incident class",
         "type": "object",
         "properties": {
           "purpose": {"$ref": "#/definitions/purpose"},
           "ext-purpose": {"type": "string"},
           "status": {"$ref": "#/definitions/status"},
           "ext-status": {"type": "string"},
           "lang": {"$ref": "#/definitions/lang"},
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "observable-id": {"$ref": "#/definitions/IDtype"},
           "IncidentID": {"$ref": "#/definitions/IncidentID"},
           "AlternativeID": {
             "$ref":"#/definitions/AlternativeID"},
           "RelatedActivity": {
             "type": "array",
             "items": {"$ref": "#/definitions/RelatedActivity"},
             "minItems": 1},
           "DetectTime": {"$ref": "#/definitions/DATETIME"},
           "StartTime": {"$ref": "#/definitions/DATETIME"},
           "EndTime": {"$ref": "#/definitions/DATETIME"},
           "RecoveryTime": {"$ref": "#/definitions/DATETIME"},
           "ReportTime": {"$ref": "#/definitions/DATETIME"},
           "GenerationTime": {"$ref": "#/definitions/DATETIME"},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "Discovery": {
             "type": "array",
             "items": {"$ref": "#/definitions/Discovery"},
             "minItems": 1},
           "Assessment": {
             "type": "array",
             "items": {"$ref": "#/definitions/Assessment"},
             "minItems": 1},
           "Method": {
             "type": "array",
             "items": {"$ref": "#/definitions/Method"},
             "minItems": 1},
           "Contact": {
             "type": "array",
             "items": {"$ref": "#/definitions/Contact"},
             "minItems": 1},
           "EventData": {
             "type": "array",
             "items": {"$ref": "#/definitions/EventData"},
             "minItems": 1},
           "Indicator": {
             "type": "array",
             "items": {"$ref": "#/definitions/Indicator"},
             "minItems": 1},
           "History": {"$ref": "#/definitions/History"},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": ["IncidentID", "GenerationTime", "Contact",
           "purpose"],
         "additionalProperties": false},
       "IncidentID": {
         "title": "IncidentID",
         "description": "JSON schema for IncidentID class",
         "type": "object",
         "properties": {
           "id": {"type": "string"},
           "name": {"type": "string"},
           "instance": {"type": "string"},
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"}},
         "required": ["id", "name"],
         "additionalProperties": false},
       "AlternativeID": {
         "title": "AlternativeID",
         "description": "JSON schema for AlternativeID class",
         "type": "object",
         "properties": {
           "IncidentID": {
             "type": "array",
             "items":{"$ref": "#/definitions/IncidentID"},
             "minItems": 1},
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"}},
         "required": ["IncidentID"],
         "additionalProperties": false},
       "RelatedActivity": {
         "properties": {
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "IncidentID": {
             "type": "array",
             "items": {"$ref": "#/definitions/IncidentID"},
             "minItems": 1},
           "URL": {
             "type": "array",
             "items": {"$ref": "#/definitions/URLtype"},
             "minItems": 1},
           "ThreatActor": {
             "type": "array",
             "items": {"$ref": "#/definitions/ThreatActor"},
             "minItems": 1},
           "Campaign": {
             "type": "array",
             "items": {"$ref": "#/definitions/Campaign"},
             "minItems": 1},
           "IndicatorID": {
             "type": "array",
             "items": {"$ref": "#/definitions/IndicatorID"},
             "minItems": 1},
           "Confidence": {"$ref": "#/definitions/Confidence"},
           "Description": {
             "type": "array",
             "items": {"type": "string"},
             "minItems": 1},
           "AdditionalData": {
             "$ref": "#/definitions/ExtensionTypeList"}},
         "additionalProperties": false},
       "ThreatActor": {
         "properties": {
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "ThreatActorID": {
             "type": "array",
             "items": {"type": "string"},
             "minItems": 1},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "URL": {
             "type":"array",
             "items":{"$ref":"#/definitions/URLtype"},
             "minItems": 1},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "additionalProperties": false},
       "Campaign": {
         "properties": {
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "CampaignID": {
             "type": "array",
             "items": {"type": "string"},
             "minItems": 1},
           "URL": {
             "type":"array",
             "items":{"$ref":"#/definitions/URLtype"},
             "minItems": 1},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}}},
       "Contact": {
         "type": "object",
         "properties": {
           "role": {
             "enum":["creator", "reporter", "admin", "tech",
                     "provider", "user", "billing", "legal",
                     "irt", "abuse", "cc", "cc-irt", "leo",
                     "vendor", "vendor-support", "victim",
                     "victim-notified", "ext-value"]},
           "ext-role": {"type": "string"},
           "type": {
             "enum": ["person", "organization", "ext-value"]},
           "ext-type": {"type": "string"},
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "ContactName": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "ContactTitle": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "RegistryHandle": {
             "type":"array",
             "items":{"$ref":"#/definitions/RegistryHandle"},
             "minItems": 1},
           "PostalAddress": {
             "type":"array",
             "items":{"$ref":"#/definitions/PostalAddress"},
             "minItems": 1},
           "Email": {
             "type": "array",
             "items": {"$ref": "#/definitions/Email"},
             "minItems": 1},
           "Telephone": {
             "type": "array",
             "items": {"$ref": "#/definitions/Telephone"},
             "minItems": 1},
           "Timezone": {"$ref": "#/definitions/TimeZonetype"},
           "Contact": {
             "type": "array",
             "items": {"$ref": "#/definitions/Contact"},
             "minItems": 1},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": ["role", "type"],
         "additionalProperties": false},
       "RegistryHandle": {
         "type": "object",
         "properties": {
           "handle": {"type": "string"},
           "registry": {
             "enum": ["internic", "apnic", "arin", "lacnic",
               "ripe", "afrinic", "local", "ext-value"]},
           "ext-registry": {"type": "string"}},
         "required": ["handle", "registry"],
         "additionalProperties": false},
       "PostalAddress": {
         "type": "object",
         "properties": {
           "type": {
             "enum": ["street", "mailing", "ext-value"]},
           "ext-type": {"type": "string"},
           "PAddress": {"$ref": "#/definitions/PAddressType"},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1}},
         "required": ["PAddress"],
         "additionalProperties": false},
       "Email": {
         "type": "object",
         "properties": {
           "type": {
             "enum":["direct", "hotline", "ext-value"]},
           "ext-type": {"type": "string"},
           "EmailTo": {"type": "string"},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1}},
         "required": ["EmailTo"],
         "additionalProperties": false},
       "Telephone": {
         "type": "object",
         "properties": {
           "type": {
             "enum":["wired", "mobile", "fax", "hotline",
               "ext-value"]},
           "ext-type": {"type": "string"},
           "TelephoneNumber": {"type": "string"},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1}},
         "required": ["TelephoneNumber"],
         "additionalProperties": false},
       "Discovery": {
         "type": "object",
         "properties": {
           "source": {
             "enum":["nidps", "hips", "siem", "av",
               "third-party-monitoring", "incident", "os-log",
               "application-log", "device-log", "network-flow",
               "passive-dns", "investigation", "audit",
               "internal-notification", "external-notification",
               "leo", "partner", "actor", "unknown", "ext-value"]},
           "ext-source": {"type": "string"},
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "Contact": {
             "type": "array",
             "items": {"$ref": "#/definitions/Contact"},
             "minItems": 1},
           "DetectionPattern": {
             "type":"array",
             "items":{"$ref":"#/definitions/DetectionPattern"},
             "minItems": 1}},
         "required": [],
         "additionalProperties": false},
       "DetectionPattern": {
         "type": "object",
         "properties": {
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "observable-id": {"$ref": "#/definitions/IDtype"},
           "Application": {"$ref": "#/definitions/SoftwareType"},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "DetectionConfiguration": {
             "type": "array",
             "items": {"type": "string"},
             "minItems": 1}},
         "allOf": [
           {"required": ["Application"]},
           {"oneOf": [
             {"required":["Description"]},
             {"required":["DetectionConfiguration"]}]}],
         "additionalProperties": false},
       "Method": {
         "type": "object",
         "properties": {
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "Reference": {
             "type": "array",
             "items": {"$ref": "#/definitions/Reference"},
             "minItems": 1},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "AttackPattern": {
             "type":"array",
             "items":{"$ref":"#/definitions/STRUCTUREDINFO"},
             "minItems": 1},
           "Vulnerability": {
             "type":"array",
             "items":{"$ref":"#/definitions/STRUCTUREDINFO"},
             "minItems": 1},
           "Weakness": {
             "type":"array",
             "items":{"$ref":"#/definitions/STRUCTUREDINFO"},
             "minItems": 1},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": [],
         "additionalProperties": false},
       "Reference": {
         "type": "object",
         "properties": {
           "observable-id": {"$ref": "#/definitions/IDtype"},
           "ReferenceName": {
             "$ref":"#/definitions/ReferenceName"},
           "URL":{
             "type":"array",
             "items":{"$ref":"#/definitions/URLtype"},
             "minItems": 1},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1}},
         "required": [],
         "additionalProperties": false},
       "ReferenceName" : {
         "type": "object",
         "properties": {
           "specIndex": {"type": "number"},
           "ID": {"$ref":"#/definitions/IDtype"}},
         "required": ["specIndex", "ID"],
         "additionalProperties": false},
       "Assessment": {
         "type": "object",
         "properties": {
           "occurrence": {"enum":["actual", "potential"]},
           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "observable-id": {"$ref": "#/definitions/IDtype"},
           "IncidentCategory": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "Impact": {
            "type": "array",
            "items": {
              "properties": {
                "SystemImpact":{
                  "$ref":"#/definitions/SystemImpact"},
                "BusinessImpact":{
                  "$ref":"#/definitions/BusinessImpact"},
                "TimeImpact":{"$ref":"#/definitions/TimeImpact"},
                "MonetaryImpact":{
                  "$ref":"#/definitions/MonetaryImpact"},
                "IntendedImpact":{
                  "$ref":"#/definitions/BusinessImpact"}},
              "additionalProperties":false},
            "minItems" : 1
           },
           "Counter": {
             "type": "array",
             "items": {"$ref": "#/definitions/Counter"},
             "minItems": 1},
           "MitigatingFactor": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "Cause": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "Confidence": {"$ref": "#/definitions/Confidence"},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": ["Impact"],
         "additionalProperties": false},
       "SystemImpact": {
         "type": "object",
         "properties": {
           "severity": {"enum":["low", "medium", "high"]},
           "completion": {"enum":["failed", "succeeded"]},
           "type": {
             "enum":["takeover-account", "takeover-service",
               "takeover-system", "cps-manipulation", "cps-damage",
               "availability-data", "availability-account",
               "availability-service", "availability-system",
               "damaged-system", "damaged-data",
               "breach-proprietary", "breach-privacy",
               "breach-credential", "breach-configuration",
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           "restriction": {"$ref": "#/definitions/restriction",
                           "default": "private"},
           "ext-restriction": {"type": "string"},
           "System": {"$ref": "#/definitions/System"},
           "Address": {"$ref": "#/definitions/Address"},
           "DomainData": {"$ref": "#/definitions/DomainData"},
           "EmailData": {"$ref": "#/definitions/EmailData"},
           "Service": {"$ref": "#/definitions/Service"},
           "WindowsRegistryKeysModified": {
             "$ref": "#/definitions/WindowsRegistryKeysModified"},
           "FileData": {"$ref": "#/definitions/FileData"},
           "CertificateData": {
             "$ref": "#/definitions/CertificateData"},
           "RegistryHandle": {
             "$ref": "#/definitions/RegistryHandle"},
           "RecordData":  {"$ref": "#/definitions/RecordData"},
           "EventData": {"$ref": "#/definitions/EventData"},
           "Incident": {"$ref": "#/definitions/Incident"},
           "Expectation": {"$ref": "#/definitions/Expectation"},
           "Reference": {"$ref": "#/definitions/Reference"},
           "Assessment": {"$ref": "#/definitions/Assessment"},
           "DetectionPattern": {
             "$ref": "#/definitions/DetectionPattern"},
           "HistoryItem": {"$ref": "#/definitions/HistoryItem"},
           "BulkObservable": {
             "$ref": "#/definitions/BulkObservable"},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
           "oneOf": [
             {"required":["System"]},
             {"required":["Address"]},
             {"required":["DomainData"]},
             {"required":["EmailData"]},
             {"required":["Service"]},
             {"required":["WindowsRegistryKeysModified"]},
             {"required":["FileData"]},
             {"required":["CertificateData"]},
             {"required":["RegistryHandle"]},
             {"required":["RecordData"]},
             {"required":["EventData"]},
             {"required":["Incident"]},
             {"required":["Expectation"]},
             {"required":["Reference"]},
             {"required":["Assessment"]},
             {"required":["DetectionPattern"]},
             {"required":["HistoryItem"]},
             {"required":["BulkObservable"]},
             {"required":["AdditionalData"]}],
         "additionalProperties": false},
       "BulkObservable": {
         "type": "object",
         "properties": {
           "type": {"enum": ["asn", "atm", "e-mail", "ipv4-addr",
             "ipv4-net", "ipv4-net-mask", "ipv6-addr", "ipv6-net",
             "ipv6-net-mask", "mac", "site-uri", "domain-name",
             "domain-to-ipv4", "domain-to-ipv6",
             "domain-to-ipv4-timestamp",
             "domain-to-ipv6-timestamp", "ipv4-port", "ipv6-port",
             "windows-reg-key", "file-hash", "email-x-mailer",
             "email-subject", "http-user-agent",
             "http-request-url", "mutex", "file-path", "user-name",
             "ext-value"]},
           "ext-type": {"type": "string"},
           "BulkObservableFormat":{
             "$ref": "#/definitions/BulkObservableFormat"},
           "BulkObservableList": {"type": "string"},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": ["BulkObservableList"],
         "additionalProperties": false},
       "BulkObservableFormat": {
         "type": "object",
         "properties": {
           "Hash": {"$ref": "#/definitions/Hash"},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "oneOf": [
            {"required": ["Hash"]},
            {"required": ["AdditionalData"]}
         ],
         "additionalProperties": false},
       "IndicatorExpression": {
         "type": "object",
         "properties": {
           "operator": {
             "enum": ["not", "and", "or", "xor"], "default": "and"},
           "ext-operator": {"type": "string"},
           "IndicatorExpression": {
             "type": "array",
             "items": {
               "$ref": "#/definitions/IndicatorExpression"},
             "minItems": 1},
           "Observable": {
             "type": "array",
             "items": {"$ref": "#/definitions/Observable"},
             "minItems": 1},
           "uid-ref": {
             "type": "array",
             "items": {"$ref": "#/definitions/IDREFType"},
             "minItems": 1},
           "IndicatorReference": {
             "type": "array",
             "items": {
               "$ref": "#/definitions/IndicatorReference"},
             "minItems": 1},
           "Confidence": {"$ref":"#/definitions/Confidence"},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": [],
         "additionalProperties": false},
       "IndicatorReference": {
         "type": "object",
         "properties": {
           "uid-ref": {"$ref":"#/definitions/IDREFType"},
           "euid-ref": {"type": "string"},
           "version": {"type": "string"}},
         "oneOf": [
            {"required": ["uid-ref"]},
            {"required": ["euid-ref"]}
         ],
         "additionalProperties": false},
       "AttackPhase": {
         "type": "object",
         "properties": {
           "AttackPhaseID": {
             "type": "array",
             "items": {"type": "string"},
             "minItems": 1},
           "URL": {
             "type": "array",
             "items": {"$ref": "#/definitions/URLtype"},
             "minItems": 1},
           "Description": {
             "type": "array",
             "items": {"$ref": "#/definitions/MLStringType"},
             "minItems": 1},
           "AdditionalData": {
             "$ref":"#/definitions/ExtensionTypeList"}},
         "required": [],
         "additionalProperties": false}},
     "title": "IODEF-Document",
     "description": "JSON schema for IODEF-Document class",
     "type": "object",
     "properties": {
       "version": {"type": "string"},
       "lang": {"$ref": "#/definitions/lang"},
       "format-id": {"type": "string"},
       "private-enum-name": {"type": "string"},
       "private-enum-id": {"type": "string"},
       "Incident": {
         "type": "array",
         "items": {"$ref": "#/definitions/Incident"},
         "minItems": 1},
       "AdditionalData": {
         "$ref":"#/definitions/ExtensionTypeList"}},
     "required": ["version", "Incident"],
     "additionalProperties": false}

                           Figure 6: JSON Schema

Acknowledgments

   We would like to thank Henk Birkholz, Carsten Bormann, Benjamin
   Kaduk, Alexey Melnikov, Yasuaki Morita, and Takahiko Nagata for their
   insightful comments on this document and CDDL.

Authors' Addresses

   Takeshi Takahashi
   National Institute of Information and Communications Technology
   4-2-1 Nukui-Kitamachi, Koganei, Tokyo
   184-8795
   Japan

   Phone: +81 42 327 5862
   Email: takeshi_takahashi@nict.go.jp

   Roman Danyliw
   CERT, Software Engineering Institute, Carnegie Mellon University
   4500 Fifth Avenue
   Pittsburgh, PA
   United States of America

   Email: rdd@cert.org

   Mio Suzuki
   National Institute of Information and Communications Technology
   4-2-1 Nukui-Kitamachi, Koganei, Tokyo
   184-8795
   Japan

   Email: mio@nict.go.jp