Network Working Group                                         J.G. Gould
Internet-Draft                                                D.S. Smith
Intended status: Standards Track                          VeriSign, Inc.
Expires: 27 November 26 December 2022                                    J.K. Kolker
                                                             R.C. Carney
                                                            GoDaddy Inc.
                                                             26 May
                                                            24 June 2022

Redacted Fields in the Registration Data Access Protocol (RDAP) Response
                   draft-ietf-regext-rdap-redacted-07
                   draft-ietf-regext-rdap-redacted-08

Abstract

   This document describes an RDAP extension for explicitly identifying
   redacted RDAP response fields, using JSONPath as the default
   expression language.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on 27 November 26 December 2022.

Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   Please review these documents carefully, as they describe your rights
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
   3.  Redaction Methods . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Redaction by Removal Method . . . . . . . . . . . . . . .   4
     3.2.  Redaction by Empty Value Method . . . . . . . . . . . . .   5
     3.3.  Redaction by Replacement Value Method . . . . . . . . . .   6
   4.  Redacted RDAP Response  . . . . . . . . . . . . . . . . . . .   8
     4.1.  RDAP Conformance  . . . . . . . . . . . . . . . . . . . .   8
     4.2.  "redacted" Member . . . . . . . . . . . . . . . . . . . .   8
   5.  JSONPath Considerations . . . . . . . . . . . . . . . . . . .  29
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  30
     6.1.  RDAP Extensions Registry  . . . . . . . . . . . . . . . .  31
     6.2.  JSON Values Registry  . . . . . . . . . . . . . . . . . .  31
   7.  Implementation Status . . . . . . . . . . . . . . . . . . . .  31
     7.1.  IIT-CNR/Registro.it RDAP Server . . . . . . . . . . . . .  32
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  32
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  32
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  32
     10.1.  Informative References . . . . . . . . . . . . . . . . .  32
     10.2.  Normative References . . . . . . . . . . . . . . . . . .  33
   Appendix A.  Change History . . . . . . . . . . . . . . . . . . .  34
     A.1.  Change from 00 to 01  . . . . . . . . . . . . . . . . . .  34
     A.2.  Change from 01 to 02  . . . . . . . . . . . . . . . . . .  35
     A.3.  Change from 02 to 03  . . . . . . . . . . . . . . . . . .  35
     A.4.  Change from 03 to 04  . . . . . . . . . . . . . . . . . .  35
     A.5.  Change from 04 to 05  . . . . . . . . . . . . . . . . . .  36
     A.6.  Change from 05 to 06  . . . . . . . . . . . . . . . . . .  36
     A.7.  Change from 06 to 07  . . . . . . . . . . . . . . . . . .  36
     A.8.  Change from 07 to 08  . . . . . . . . . . . . . . . . . .  36
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  36

1.  Introduction

   This document describes an RDAP extension for explicitly identifying
   redacted RDAP response fields, using JSONPath as the default
   expression language.  A redacted RDAP field is one that has data
   removed from or replaced in the RDAP response due to server policy, such
   as the lack of client privilege to receive the field.  This extension
   can be used to identify redacted RDAP fields in any RDAP object
   class, as defined in [RFC9083], or RDAP fields defined in RDAP
   extensions.  Because an RDAP response may exclude a field due to
   either the lack of data or based on the lack of RDAP client
   privileges, this extension is used to explicitly specify which RDAP
   fields are not included in the RDAP response due to redaction.  It
   thereby provides a capability for disambiguation between redaction
   and possible other reasons for data or field absence.

   In [RFC9082] RDAP supports both lookup and search queries, where a
   lookup query responds with a single object and a search query
   responds with a list of objects.  This document applies to redaction
   of a single object of a lookup response and in each of the objects of
   a search response.

   JSONPath, as defined in [I-D.ietf-jsonpath-base], is used as the
   default expression language to reference RDAP fields that have been
   redacted.  The redacted JSON fields will either be removed or have
   empty values in the RDAP response.  JSON is defined by [RFC8259].

2.  Conventions Used in This Document

   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.

   The JSON examples include extra line breaks and whitespace.  For
   instance, the JSONPath expressions are broken out into multiple lines
   when required for illustration.

3.  Redaction Methods

   Redaction in RDAP can be handled in multiple ways.  The use of
   placeholder text for the values of the RDAP fields, such as the
   placeholder text "XXXX", MUST NOT be used for redaction.  A
   placeholder text value will not match the format requirements of each
   of the RDAP fields and provides an inconsistent and unreliable
   redaction signal.  This section covers the redaction methods that can
   be used with the redaction signaling defined in Section 4.2.

   RDAP responses, as defined in [RFC9083], include a mix of JSON
   objects and JSON arrays, where JSON arrays are heavily used for
   entity objects with jCard [RFC7095].  jCard [RFC7095] is a JSON
   representation of vCard [RFC6350] that inherits its dependency on
   arrays.  An example is the vCard [RFC6350] "ADR" property / jCard
   [RFC7095] "adr" property that defines a sequence of address
   components.  According to [RFC6350], when an "ADR" property component
   value is missing, the associated component separator MUST still be
   specified.  jCard [RFC7095] extends the use of arrays with each
   individual vCard property being represented by an array of three
   fixed elements, followed by one or more additional elements.  The mix
   of JSON objects and JSON arrays impacts the methods used for
   redaction in RDAP.

   The redaction of RDAP fields fall into the two three categories of
   Redaction by Removal Method (Section 3.1) and Redaction by Empty
   Value Method (Section 3.2), defined
   in the following sub-sections.

3.1.  Redaction by Removal Method

   The Redaction by Removal Method is when the RDAP field is removed
   from the RDAP response, which is the preferred method.  The Redaction
   by Removal Method can be done for all RDAP response fields other than
   response fields using the position in an array to signal the redacted
   field (e.g., the JSON arrays used with jCard [RFC7095]).  RDAP
   extensions such as JSContact in Registration Data Access Protocol
   (RDAP) JSON Responses [I-D.ietf-regext-rdap-jscontact] do not have a
   dependency on the use of positional JSON arrays and are therefore
   suited for the Redaction by Removal Method.

   When an RDAP object is redacted by removal, all of the RDAP object's
   child fields are also removed.  Only the redacted RDAP object needs
   to be referenced in the list of redacted fields, as defined in
   Section 4.2.

   An example of redacting an RDAP object is removing the administrative
   contact from the RDAP response and including the following "redacted"
   member:

   "redacted": [
     {
       "name": {
         "type": "Administrative Contact"
       },
       "path": "$.entities[?(@.roles[0]=='administrative')]",
       "method": "removal"
     }
   ]

                 Figure 1: Redacted Administrative Contact

   The Redaction by Removal Method MUST NOT be used to remove a field
   using the position in a fixed length array to signal the redacted
   field.  For example, removal of an individual data field in jCard
   [RFC7095] will result in a non-conformant jCard [RFC7095] array
   definition.

3.2.  Redaction by Empty Value Method

   The Redaction by Empty Value Method is when a redacted field is not
   removed, but its value is set to an empty value, such as "" for a
   jCard [RFC7095] Text ("text") property or null for non-Text ("text")
   properties.  The empty jCard [RFC7095] values ("" or null) are
   referenced in the "redacted" member in place of the jCard [RFC7095]
   property name, such as referencing the "fn" jCard property value at
   position 3 instead of referencing the "fn" jCard property name at
   position 0.  The Redaction by Empty Value Method SHOULD be used only
   when redacting JSON response fields that use the position in an array
   to signal the redacted field (e.g., jCard [RFC7095] arrays).
   Optional jCard [RFC7095] properties SHOULD use the Redaction by
   Removal Method (Section 3.1) to redact the entire property.  The
   required jCard [RFC7095] "fn" property, defined in section 6.2.1 of
   vCard [RFC6350], MUST use the Redaction by Empty Value Method to
   redact the property value.  Removing the "fn" property would violate
   vCard [RFC6350] and removing the property value would violate the
   fixed array positions defined in jCard [RFC7095].

   An example of the redacted "fn" jCard property using the Redaction by
   Empty Value Method:

   [
     "fn",
     {},
     "text",
     ""
   ]

      Figure 2: Redacted "fn" jCard property using Redaction by Empty
                                Value Method

   An example of the "redacted" member for the redacted "fn" jCard
   property value, which is array position 3:

   "redacted": [
     {
       "name": {
         "type": "Registrant Name"
       },
       "path": "$.entities[?(@.roles[0]=='registrant')].
         vcardArray[1][?(@[0]=='fn')][3]",
       "pathLang": "jsonpath",
       "method": "emptyValue",
       "reason": {
         "type": "Server policy"
       }
     }
   ]

          Figure 3: Redacted Registrant Name using Array Position

3.3.  Redaction by Replacement Value Method

   The Redaction by Replacement Value Method is when a redacted field is
   not removed, but its value is replaced with a different value, such
   as protecting the "email" jCard [RFC7095] property value with an
   anonymized email "text" value or the use of an alternate "uri" value
   to a web form.  Replacing a property value is a form of redaction,
   since it protects the true property value for privacy reasons.

   An example of the redacted "email" jCard property using the Redaction
   by Replacement Value Method with an anonymized email:

   [
     "email",
     {},
     "text",
     "anonymized123@example.com"
   ]

        Figure 4: Redacted "email" jCard property using Redaction by
             Replacement Value Method with an anonymized email

   An example of the "redacted" member for the redacted registrant
   "email" jCard property value with an anonymized "text" value.

   "redacted": [
     {
       "name": {
         "type": "Registrant Email"
       },
       "path": "$.entities[?(@.roles[0]=='registrant')].
                  vcardArray[1][?(@[0]=='email')][3]",
       "pathLang": "jsonpath",
       "method": "replacementValue",
     }
   ]

          Figure 5: Redacted Email using Replacement Value with an
                          anonymized "text" value

   An example of the redacted "email" jCard property using the Redaction
   by Replacement Value Method with a [RFC8605] "contact-uri" jCard
   property to a web form:

   [
     "contact-uri",
     {},
     "uri",
     "https://email.example.com/123"
   ]

        Figure 6: Redacted "email" jCard property using Redaction by
     Replacement Value Method with a "contact-uri" jCard property to a
                                  web form

   An example of the "redacted" member for the redacted registrant
   "email" jCard property value with a [RFC8605] "contact-uri" jCard
   property to a web form:

   "redacted": [
     {
       "name": {
         "type": "Registrant Email"
       },
       "path": "$.entities[?(@.roles[0]=='registrant')].
                  vcardArray[1][?(@[0]=='email')][3]",
       "replacementPath": "$.entities[?(@.roles[0]=='registrant')].
                  vcardArray[1][?(@[0]=='contact-uri')][3]",
       "pathLang": "jsonpath",
       "method": "replacementValue",
     }
   ]
     Figure 7: Redacted Email using Replacement Value with a "contact-
                     uri" jCard property to a web form

4.  Redacted RDAP Response

4.1.  RDAP Conformance

   RDAP responses that contain values described in this document MUST
   indicate conformance with this specification by including an
   "rdapConformance" ([RFC9083]) value of "redacted_level_0_3".  The
   "redacted_level_0_3" extension identifier is described in
   Section 6.1.

   Example "rdapConformance" member with the redacted extension:

   "rdapConformance": [
     "rdap_level_0",
     "redacted_level_0_3"
   ]

            Figure 8: "rdapConformance" with Redacted Extension

4.2.  "redacted" Member

   The "redacted" member MUST be added to the RDAP response when there
   are
   is one or more redacted fields.  The "redacted" member is included as
   a member of the object class in a lookup response, such as the object
   classes defined in [RFC9083], and as a member of the object instances
   in a search response, such as the object instances defined in
   [RFC9083].  The "redacted" member contains an array of redacted
   objects with the following child members:

   "name":  A logical name for the redacted field.  The logical name
       used for the redacted field is up to server policy.  The logical
       name is defined using an object with a "type" field denoting a
       registered redacted name (see Section 6.2) or a "description"
       field denoting an unregistered redacted name.  The registered
       redacted names and the chosen unregistered names can meet the
       needs of different RDAP services or industries.

   "path":  The JSON expression references a removed JSON field in the
       case of Redaction By Removal Method (Section 3.1), an empty field
       in the case of Redaction by Empty Value Method (Section 3.2), or
       the field that is replaced in the case of Redaction by
       Replacement Value Method (Section 3.3).  The replaced field can
       be either removed or empty when using a replacement field
       referenced by the "replacementPath" member.

   "replacementPath":  OPTIONAL JSON expression of the replacement field
       of the redacted field with the Redaction by Replacement Value
       Method (Section 3.3), using the expression language defined by
       the "pathLang" member.

   "pathLang":  OPTIONAL JSON path expression language used, with the
       default value of "jsonpath" for JSONPath
       ([I-D.ietf-jsonpath-base]).  Other JSON path expression languages
       MAY be used based on server policy.

   "method":  OPTIONAL redaction method used used; with one of the following
       values:

       *  "removal" indicating the Redaction By Removal Method
          (Section 3.1),

       *  "emptyValue" indicating the Redaction by Empty Value Method
          (Section 3.2), and or

       *  "replacementValue" indicating the Redaction by Replacement
          Value
       Method Method.  (Section 3.3). 3.3)

       The default value is "removal" when not provided.

   "reason":  OPTIONAL human readable reason(s) for the redacted field
       in the language defined by the [RFC9083] "lang" member.  The
       default language is "en" if the [RFC9083] "lang" member is not
       specified.  The reason is defined using an object with an
       OPTIONAL "type" field denoting a registered redacted reason (see
       see Section 6.2) and an OPTIONAL "description" field denoting an
       unregistered redacted reason.  The "description" field MUST NOT
       be a client processing dependency.

   Example unredacted version of an RDAP lookup response:

       {
         "rdapConformance": [
           "rdap_level_0"
         ],
         "objectClassName": "domain",
         "handle": "ABC123",
         "ldhName": "example.com",
         "secureDNS": {
           "delegationSigned": false
         },
         "notices": [
           {
             "title": "Terms of Use",
             "description": [
               "Service subject to Terms of Use."
             ],
             "links": [
               {
                 "rel": "self",
                 "href": "https://www.example.com/terms-of-use",
                 "type": "text/html",
                 "value": "https://www.example.com/terms-of-use"
               }
             ]
           }
         ],
         "nameservers": [
           {
             "objectClassName": "nameserver",
             "ldhName": "ns1.example.com"
           },
           {
             "objectClassName": "nameserver",
             "ldhName": "ns2.example.com"
           }
         ],
         "entities": [
           {
             "objectClassName": "entity",
             "handle": "123",
             "roles": [
               "registrar"
             ],
             "publicIds": [
               {
                 "type": "IANA Registrar ID",
                 "identifier": "1"
               }
             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   "Example Registrar Inc."
                 ],
                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "Suite 100",
                     "123 Example Dr.",
                     "Dulles",
                     "VA",
                     "20166-6503",
                     "US"
                   ]
                 ],
                 [
                   "email",
                   {},
                   "text",
                   "contact@organization.example"
                 ],
                 [
                   "tel",
                   {
                     "type": "voice"
                   },
                   "uri",
                   "tel:+1.7035555555;ext=1234"
                 ],
                 [
                   "tel",
                   {
                     "type": "fax"
                   },
                   "uri",
                   "tel:+1.7035555556"
                 ]
               ]
             ],
             "entities": [
               {
                 "objectClassName": "entity",
                 "roles": [
                   "abuse"
                 ],
                 "vcardArray": [
                   "vcard",
                   [
                     [
                       "version",
                       {},
                       "text",
                       "4.0"
                     ],
                     [
                       "fn",
                       {},
                       "text",
                       "Abuse Contact"
                     ],
                     [
                       "email",
                       {},
                       "text",
                       "abuse@organization.example"
                     ],
                     [
                       "tel",
                       {
                         "type": "voice"
                       },
                       "uri",
                       "tel:+1.7035555555;ext=1234"
                     ]
                   ]
                 ]
               }
             ]
           },
           {
             "objectClassName": "entity",
             "handle": "XXXX",
             "roles": [
               "registrant"
             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],

                 [
                   "fn",
                   {},
                   "text",
                   "Registrant User"
                 ],
                 [
                   "org",
                   {},
                   "text",
                   "Example Inc."
                 ],
                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "Suite 1235",
                     "4321 Rue Somewhere",
                     "Quebec",
                     "QC",
                     "G1V 2M2",
                     "Canada"
                   ]
                 ],
                 [
                   "email",
                   {},
                   "text",
                   "registrant.user@example.com"
                 ],
                 [
                   "tel",
                   {
                     "type": "voice"
                   },
                   "uri",
                   "tel:+1-555-555-1235;ext=123"
                 ],
                 [
                   "tel",
                   {
                     "type": "fax"
                   },
                   "uri",
                   "tel:+1-555-555-5321"
                 ]

               ]
             ]
           },
           {
             "objectClassName": "entity",
             "handle": "YYYY",
             "roles": [
               "technical"
             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   "Technical User"
                 ],
                 [
                   "org",
                   {},
                   "text",
                   "Example Inc."
                 ],
                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "Suite 1234",
                     "4321 Rue Somewhere",
                     "Quebec",
                     "QC",
                     "G1V 2M2",
                     "Canada"
                   ]
                 ],
                 [
                   "email",
                   {},
                   "text",
                   "technical.user@example.com"
                 ],
                 [
                   "tel",
                   {
                     "type": "voice"
                   },
                   "uri",
                   "tel:+1-555-555-1234;ext=321"
                 ],
                 [
                   "tel",
                   {
                     "type": "fax"
                   },
                   "uri",
                   "tel:+1-555-555-4321"
                 ]
               ]
             ]
           },
           {
             "objectClassName": "entity",
             "handle": "ZZZZ",
             "roles": [
               "administrative"
             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   "Administrative User"
                 ],
                 [
                   "org",
                   {},
                   "text",
                   "Example Inc."
                 ],

                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "Suite 1236",
                     "4321 Rue Somewhere",
                     "Quebec",
                     "QC",
                     "G1V 2M2",
                     "Canada"
                   ]
                 ],
                 [
                   "email",
                   {},
                   "text",
                   "administrative.user@example.com"
                 ],
                 [
                   "tel",
                   {
                     "type": "voice"
                   },
                   "uri",
                   "tel:+1-555-555-1236;ext=789"
                 ],
                 [
                   "tel",
                   {
                     "type": "fax"
                   },
                   "uri",
                   "tel:+1-555-555-6321"
                 ]
               ]
             ]
           },
           {
             "objectClassName": "entity",
             "handle": "WWWW",
             "roles": [
               "billing"
             ],
             "vcardArray": [
               "vcard",
               [

                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   "Billing User"
                 ],
                 [
                   "email",
                   {},
                   "text",
                   "billing.user@example.com"
                 ]
               ]
             ]
           }
         ],
         "events": [
           {
             "eventAction": "registration",
             "eventDate": "1997-06-03T00:00:00Z"
           },
           {
             "eventAction": "last changed",
             "eventDate": "2020-05-28T01:35:00Z"
           },
           {
             "eventAction": "expiration",
             "eventDate": "2021-06-03T04:00:00Z"
           }
         ],
         "status": [
           "server delete prohibited",
           "server update prohibited",
           "server transfer prohibited",
           "client transfer prohibited"
         ]
       }

                 Figure 9: Unredacted RDAP Lookup Response

   Example redacted version of an RDAP lookup response:

       {
         "rdapConformance": [
           "rdap_level_0",
           "redacted_level_0_3"
         ],
         "objectClassName": "domain",
         "ldhName": "example.com",
         "secureDNS": {
           "delegationSigned": false
         },
         "notices": [
           {
             "title": "Terms of Use",
             "description": [
               "Service subject to Terms of Use."
             ],
             "links": [
               {
                 "rel": "self",
                 "href": "https://www.example.com/terms-of-use",
                 "type": "text/html",
                 "value": "https://www.example.com/terms-of-use"
               }
             ]
           }
         ],
         "nameservers": [
           {
             "objectClassName": "nameserver",
             "ldhName": "ns1.example.com"
           },
           {
             "objectClassName": "nameserver",
             "ldhName": "ns2.example.com"
           }
         ],
         "entities": [
           {
             "objectClassName": "entity",
             "handle": "123",
             "roles": [
               "registrar"
             ],
             "publicIds": [
               {
                 "type": "IANA Registrar ID",
                 "identifier": "1"
               }

             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   "Example Registrar Inc."
                 ],
                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "Suite 100",
                     "123 Example Dr.",
                     "Dulles",
                     "VA",
                     "20166-6503",
                     "US"
                   ]
                 ],
                 [
                   "email",
                   {},
                   "text",
                   "contact@organization.example"
                 ],
                 [
                   "tel",
                   {
                     "type": "voice"
                   },
                   "uri",
                   "tel:+1.7035555555"
                 ],
                 [
                   "tel",
                   {
                     "type": "fax"

                   },
                   "uri",
                   "tel:+1.7035555556"
                 ]
               ]
             ],
             "entities": [
               {
                 "objectClassName": "entity",
                 "roles": [
                   "abuse"
                 ],
                 "vcardArray": [
                   "vcard",
                   [
                     [
                       "version",
                       {},
                       "text",
                       "4.0"
                     ],
                     [
                       "fn",
                       {},
                       "text",
                       "Abuse Contact"
                     ],
                     [
                       "email",
                       {},
                       "text",
                       "abuse@organization.example"
                     ],
                     [
                       "tel",
                       {
                         "type": "voice"
                       },
                       "uri",
                       "tel:+1.7035555555"
                     ]
                   ]
                 ]
               }
             ]
           },
           {
             "objectClassName": "entity",
             "handle": "XXXX",
             "roles": [
               "registrant"
             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   ""
                 ],
                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "",
                     "",
                     "",
                     "QC",
                     "",
                     "Canada"
                   ]
                 ]
               ]
             ]
           },
           {
             "objectClassName": "entity",
             "handle": "YYYY",
             "roles": [
               "technical"
             ],
             "vcardArray": [
               "vcard",
               [
                 [
                   "version",
                   {},
                   "text",
                   "4.0"
                 ],
                 [
                   "fn",
                   {},
                   "text",
                   ""
                 ],
                 [
                   "org",
                   {},
                   "text",
                   "Example Inc."
                 ],
                 [
                   "adr",
                   {},
                   "text",
                   [
                     "",
                     "Suite 1234",
                     "4321 Rue Somewhere",
                     "Quebec",
                     "QC",
                     "G1V 2M2",
                     "Canada"
                   ]
                 ]
               ]
             ]
           }
         ],
         "events": [
           {
             "eventAction": "registration",
             "eventDate": "1997-06-03T00:00:00Z"
           },
           {
             "eventAction": "last changed",
             "eventDate": "2020-05-28T01:35:00Z"
           },
           {
             "eventAction": "expiration",
             "eventDate": "2021-06-03T04:00:00Z"
           }
         ],
         "status": [
           "server delete prohibited",
           "server update prohibited",
           "server transfer prohibited",
           "client transfer prohibited"
         ],
         "redacted": [
           {
             "name": {
               "type": "Registry Domain ID"
             },
             "path": "$.handle",
             "pathLang": "jsonpath",
             "method": "removal",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant Name"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[0]=='fn')][3]",
             "pathLang": "jsonpath",
             "method": "emptyValue",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant Organization"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[0]=='org')]",
             "pathLang": "jsonpath",
             "method": "removal",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant Street"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[0]=='adr')][3][:3]",
             "pathLang": "jsonpath",
             "method": "emptyValue",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant City"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[0]=='adr')][3][3]",
             "pathLang": "jsonpath",
             "method": "emptyValue",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant Postal Code"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[0]=='adr')][3][5]",
             "pathLang": "jsonpath",
             "method": "emptyValue",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant Email"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[0]=='email')]",
             "method": "removal",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Registrant Phone"
             },
             "path": "$.entities[?(@.roles[0]=='registrant')].
               vcardArray[1][?(@[1].type=='voice')]",
             "method": "removal",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Technical Name"
             },
             "path": "$.entities[?(@.roles[0]=='technical')].
               vcardArray[1][?(@[0]=='fn')][3]",
             "method": "emptyValue",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Technical Email"
             },
             "path": "$.entities[?(@.roles[0]=='technical')].
               vcardArray[1][?(@[0]=='email')]",
             "method": "removal",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Technical Phone"
             },
             "path": "$.entities[?(@.roles[0]=='technical')].
               vcardArray[1][?(@[1].type=='voice')]",
             "method": "removal",
             "reason": {
               "type": "Server policy"
             }
           },
           {
             "name": {
               "type": "Technical Fax"
             },
             "path": "$.entities[?(@.roles[0]=='technical')].
               vcardArray[1][?(@[1].type=='fax')]",
             "reason": {
               "type": "Client request",
               "description": "Client requested the field redacted"
             }
           },
           {
             "name": {
               "description": "Administrative Contact"
             },
             "path": "$.entities[?(@.roles[0]=='administrative')]",
             "method": "removal",
             "reason": {
               "description": "Refer to the technical contact"
             }
           }
           {
             "name": {
               "description": "Billing Contact"
             },
             "path": "$.entities[?(@.roles[0]=='billing')]",
             "method": "removal",
             "reason": {
               "description": "Refer to the registrant contact"
             }
           }
         ]
       }

                  Figure 10: Redacted RDAP Lookup Response

   Example unredacted version of an RDAP search response:

     {
       "rdapConformance": [
         "rdap_level_0"
       ],
       "domainSearchResults":[
         {
           "objectClassName": "domain",
           "handle": "ABC121",
           "ldhName": "example1.com",
           "links":[
             {
               "value":"https://example.com/rdap/domain/example1.com",
               "rel":"self",
               "href":"https://example.com/rdap/domain/example1.com",
               "type":"application/rdap+json"
             },
             {
               "value":"https://example.com/rdap/domain/example1.com",
               "rel":"related",
               "href":"https://example.com/rdap/domain/example1.com",
               "type":"application/rdap+json"
             }
           ]
         },
         {
           "objectClassName": "domain",
           "handle": "ABC122",
           "ldhName": "example2.com",
           "links":[
             {
               "value":"https://example.com/rdap/domain/example2.com",
               "rel":"self",
               "href":"https://example.com/rdap/domain/example2.com",
               "type":"application/rdap+json"
             },
             {
               "value":"https://example.com/rdap/domain/example2.com",
               "rel":"related",
               "href":"https://example.com/rdap/domain/example2.com",
               "type":"application/rdap+json"
             }
           ]
         }
       ]
     }

                 Figure 11: Unredacted RDAP Search Response

   Example redacted version of an RDAP search response:

     {
       "rdapConformance": [
         "rdap_level_0",
         "redacted_level_0_3"
       ],
       "domainSearchResults":[
         {
           "objectClassName": "domain",
           "ldhName": "example1.com",
           "links":[
             {
               "value":"https://example.com/rdap/domain/example1.com",
               "rel":"self",
               "href":"https://example.com/rdap/domain/example1.com",
               "type":"application/rdap+json"
             },
             {
               "value":"https://example.com/rdap/domain/example1.com",
               "rel":"related",
               "href":"https://example.com/rdap/domain/example1.com",
               "type":"application/rdap+json"
             }
           ],
           "redacted": [
             {
               "name": {
                 "type": "Registry Domain ID"
               },
               "path": "$.domainSearchResults[0].handle",
               "pathLang": "jsonpath",
               "method": "removal",
               "reason": {
                 "type": "Server policy"
               }
             }
           ]
         },
         {
           "objectClassName": "domain",
           "ldhName": "example2.com",
           "links":[
             {
               "value":"https://example.com/rdap/domain/example2.com",
               "rel":"self",
               "href":"https://example.com/rdap/domain/example2.com",
               "type":"application/rdap+json"

             },
             {
               "value":"https://example.com/rdap/domain/example2.com",
               "rel":"related",
               "href":"https://example.com/rdap/domain/example2.com",
               "type":"application/rdap+json"
             }
           ],
           "redacted": [
             {
               "name": {
                 "type": "Registry Domain ID"
               },
               "path": "$.domainSearchResults[1].handle",
               "pathLang": "jsonpath",
               "method": "removal",
               "reason": {
                 "type": "Server policy"
               }
             }
           ]
         }
       ]
     }

                  Figure 12: Redacted RDAP Search Response

5.  JSONPath Considerations

   JSONPath [I-D.ietf-jsonpath-base] is the default JSON path expression
   language.  This section covers considerations for servers using
   [I-D.ietf-jsonpath-base] to identify redacted RDAP fields with the
   "path" member of redacted objects in the "redacted" member.  The list
   of JSONPath considerations include:

   1.  Use absolute paths with the '$' JSONPath element.  An example is
       "$.handle" for the "Registry Domain ID" in a lookup response or
       "$.domainSearchResults[0].handle" in a search response.
   2.  Validate a JSONPath expression using a non-redacted RDAP
       response, where evaluating the expression results in returning
       the redacted field.
   3.  Reference the removed object field when redacting an entire
       object by the Redaction by Removal Method (Section 3.1), where
       all of the object's child fields are explicitly removed.  An
       example is "$.entities[?(@.roles[0]=='administrative')]" for the
       entire "Administrative Contact".

   4.  When an entity has multiple roles, include "redacted" members for
       each role using the role index.  This will result in duplicate
       "redacted" members, but will enable the client to treat redaction
       consistently when there is a single role per entity or multiple
       roles per entity.  An example is when the "roles" member has the
       value '["registrant","administrative"]', redacting the "name"
       member of the entity will result in two "redacted" members with
       the JSONPath expressions "$.entities[?(@.roles[0]=='registrant')]
       .vcardArray[1][?(@[0]=='fn')][3]" and "$.entities[?(@.roles[1]=='
       administrative')].vcardArray[1][?(@[0]=='fn')][3]".
   5.  When there are multiple entities with the same role, include
       "redacted" members for each entity using the entity index instead
       of the role.  A JSONPath can be created that identifies the
       entity based on an index of a role selector nodelist, such as
       "$.entities[?(@.roles[0]=='technical')][0]" for the first entity
       with the "technical" role.  Using the entity index, such as
       "$.entities[1]", is simpler and recommended.
   6.  Reference the removed field when using the Redaction by Removal
       Method (Section 3.1).  An example is "$.handle" for the "Registry
       Domain ID".
   7.  Reference index 0 of the jCard [RFC7095] property array, which is
       the jCard [RFC7095] "name" property, with a filter expression
       containing the name of the field, when redacting a jCard
       [RFC7095] field using the Redaction by Removal Method
       (Section 3.1).  An example is "$.entities[?(@.roles[0]=='registra
       nt')].vcardArray[1][?(@[0]=='email')]" for the "Registrant
       Email".
   8.  Reference jCard [RFC7095] field value or values redacted by array
       index 3 and greater, when redacting a jCard [RFC7095] field using
       the Redaction by Empty Value Method (Section 3.2).  The jCard
       [RFC7095] property array index 3 and greater contain the property
       values, where the property values set with an empty value are
       referenced directly in place of the jCard [RFC7095] property
       name.  Servers can then systematically redact jCard [RFC7095]
       field value or values based on the JSONPath expressions and
       clients will directly know which jCard [RFC7095] property values
       have been redacted.  An example is "$.entities[?(@.roles[0]=='reg
       istrant')].vcardArray[1][?(@[0]=='fn')][3]" for the "Registrant
       Name" or "$.entities[?(@.roles[0]=='registrant')].vcardArray[1][?
       (@[0]=='adr')][3][5]" for the "Registrant Postal Code".
   9.  RDAP extensions should define any special JSONPath considerations
       required to identify redacted RDAP fields if these considerations
       are insufficient.

6.  IANA Considerations
6.1.  RDAP Extensions Registry

   IANA is requested to register the following value in the RDAP
   Extensions Registry:

   Extension identifier:  redacted_level_0_3
   Registry operator:  Any
   Published specification:  This document.
   Contact:  IESG <iesg@ietf.org>
   Intended usage:  This extension identifier is used for an
      "rdapConformance" value when returning the "redacted" member in
      the JSON response.

   Extension identifier:  redacted
   Registry operator:  Any
   Published specification:  This document.
   Contact:  IESG <iesg@ietf.org>
   Intended usage:  This extension prefix identifier is used for the
      "redacted" member returned in the JSON response.

6.2.  JSON Values Registry

   Section 10.2 of [RFC9083] defines the JSON Values Registry with pre-
   defined Type field values and the use of the "Expert Review" policy
   defined in [RFC8126].  Two new JSON Values Registry Type field values
   are used to register pre-defined redacted name and reason values:

   "redacted name":  Redacted name being registered.  The registered
       redacted name is referenced using the "type" field of the
       redacted "name" field.

   "redacted reason":  Redacted reason being registered.  The registered
       redacted reason is referenced using the "type" field of the
       redacted "reason" field.

7.  Implementation Status

   Note to RFC Editor: Please remove this section and the reference to
   RFC 7942 [RFC7942] before publication.

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in RFC 7942
   [RFC7942].  The description of implementations in this section is
   intended to assist the IETF in its decision processes in progressing
   drafts to RFCs.  Please note that the listing of any individual
   implementation here does not imply endorsement by the IETF.
   Furthermore, no effort has been spent to verify the information
   presented here that was supplied by IETF contributors.  This is not
   intended as, and must not be construed to be, a catalog of available
   implementations or their features.  Readers are advised to note that
   other implementations may exist.

   According to RFC 7942 [RFC7942], "this will allow reviewers and
   working groups to assign due consideration to documents that have the
   benefit of running code, which may serve as evidence of valuable
   experimentation and feedback that have made the implemented protocols
   more mature.  It is up to the individual working groups to use this
   information as they see fit".

7.1.  IIT-CNR/Registro.it RDAP Server

   Responsible Organization: Institute of Informatics and Telematics of
   National Research Council (IIT-CNR)/Registro.it

   Location: https://rdap.pubtest.nic.it/

   Description: This implementation includes support for RDAP queries
   using data from the public test environment of .it ccTLD.  The
   "redacted" array can be returned in the response to the domain lookup
   that is the only available to anonymous users.

   Level of Maturity: This is an "alpha" test implementation.

   Coverage: This implementation includes all of the features described
   in this specification.

   Contact Information: Mario Loffredo, mario.loffredo@iit.cnr.it

8.  Security Considerations

   The server including a redacted signal provides an unauthorized
   client additional information related to the existence of data.
   Servers MAY exclude the redacted members for RDAP fields that are
   considered a privacy issue in providing a data existence signal.

9.  Acknowledgements

   The authors wish to thank the following persons for their feedback
   and suggestions: Marc Blanchet, Scott Hollenbeck, Mario Loffredo,
   Gustavo Lozano, and Rick Wilhelm.

10.  References

10.1.  Informative References

   [I-D.ietf-regext-rdap-jscontact]
              Loffredo, M. and G. Brown, "Using JSContact in
              Registration Data Access Protocol (RDAP) JSON Responses",
              Work in Progress, Internet-Draft, draft-ietf-regext-rdap-
              jscontact-12, 2 May 2022,
              <https://datatracker.ietf.org/doc/html/draft-ietf-regext-
              rdap-jscontact-12>.

   [RFC8605]  Hollenbeck, S. and R. Carney, "vCard Format Extensions:
              ICANN Extensions for the Registration Data Access Protocol
              (RDAP)", RFC 8605, DOI 10.17487/RFC8605, May 2019,
              <https://www.rfc-editor.org/info/rfc8605>.

10.2.  Normative References

   [I-D.ietf-jsonpath-base]
              Gössner, S., Normington, G., and C. Bormann, "JSONPath:
              Query expressions for JSON", Work in Progress, Internet-
              Draft, draft-ietf-jsonpath-base-05, 25 April 2022,
              <https://datatracker.ietf.org/doc/html/draft-ietf-
              jsonpath-base-05>.

   [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>.

   [RFC6350]  Perreault, S., "vCard Format Specification", RFC 6350,
              DOI 10.17487/RFC6350, August 2011,
              <https://www.rfc-editor.org/info/rfc6350>.

   [RFC7095]  Kewisch, P., "jCard: The JSON Format for vCard", RFC 7095,
              DOI 10.17487/RFC7095, January 2014,
              <https://www.rfc-editor.org/info/rfc7095>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/info/rfc7942>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [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>.

   [RFC9082]  Hollenbeck, S. and A. Newton, "Registration Data Access
              Protocol (RDAP) Query Format", STD 95, RFC 9082,
              DOI 10.17487/RFC9082, June 2021,
              <https://www.rfc-editor.org/info/rfc9082>.

   [RFC9083]  Hollenbeck, S. and A. Newton, "JSON Responses for the
              Registration Data Access Protocol (RDAP)", STD 95,
              RFC 9083, DOI 10.17487/RFC9083, June 2021,
              <https://www.rfc-editor.org/info/rfc9083>.

Appendix A.  Change History

A.1.  Change from 00 to 01

   1.  Changed rdapConformance to use pointed "redacted_0.1" value to
       support structural changes of the extension up to the target of
       "redacted_1.0".
   2.  Updates based on the Gustavo Lozano feedback:
       1.  Updated the language to change the special treatment of jCard
           to be more generic for future RDAP extensions that leverage
           fixed length JSON arrays.
       2.  Added "RDAP extensions should define any special JSONPath
           considerations required to identify redacted RDAP fields if
           the these considerations are insufficient." to the JSONPath
           Considerations section to generalize it.
   3.  Updates based on the Marc Blanchet feedback:
       1.  Added a reference to draft-ietf-regext-rdap-jscontact as an
           example of an RDAP extension that is suited for the Redaction
           by Removal Method based on the lack of dependency on
           positional JSON arrays.
       2.  Added support for registered and unregistered (free-form)
           redaction reasons by changing the "reason" property to be a
           JSON object with the "type" and "description" properties.
           The "type" property includes registration in the IANA JSON
           Values Registry.
       3.  Added a "JSON Values Registry" section in the IANA
           Considersations section to define the "redaction reason" JSON
           Values Registry Type values to support the registration of
           redaction reasons.
   4.  Updates based on the Mario Loffredo feedback:

       1.  Added support for registered and unregistered (free-form)
           redaction names by changing the "reason" property to be a
           JSON object with the "type" and "description" properties.
           The "type" property includes registration in the IANA JSON
           Values Registry.
       2.  Added a "JSON Values Registry" section in the IANA
           Considersations section to define the "redaction name" JSON
           Values Registry Type values to support the registration of
           redaction names.
       3.  Added a JSONPath Considerations item associated with handling
           entities with multiple roles.
       4.  Added language to restrict the extension to responses.

A.2.  Change from 01 to 02

   1.  Updates to add support for RDAP search responses:
       1.  Replaced "RDAP lookup response" with "RDAP response"
           throughout the draft to expand the scope to include search.
       2.  Updated the description in the second paragraph of the
           Introduction to cover both a lookup response and a search
           response.
       3.  Added an example of the use of an absoluate path for a search
           response to the "JSONPath Considerations" section.
       4.  Added a description of the placement of the "redacted" member
           in a lookup response and a search response in the ""redacted"
           Member" section.
       5.  Added an example of an unredacted search response and a
           redacted search response in the ""redacted" Member" section.

A.3.  Change from 02 to 03

   1.  Fixed mismatch of the extension identifier, which was updated to
       "redacted_0.1" throughout the draft based on feedback from Mario
       Loffredo.
   2.  Added the JSONPath Considerations item associated with redacting
       fields for multiple entities with the same role based on
       implementation feedback from Mario Loffredo.
   3.  Added the Implementation Status section that includes the server
       implementation by Mario Loffredo.
   4.  Added use of numbered figures for easy reference for JSON Values
       Registry registrations.
   5.  Updated the example unredacted and redacted lookup responses to
       include the "objectClassName" and "handle" members.
   6.  Changed RFC7482 and RFC7483 references to RFC9082 and RFC9083,
       respectively.

A.4.  Change from 03 to 04
   1.  Changed the extension identifier to be "redacted" instead of a
       versioned value, which will be leveraged for both the
       rdapConformance value and the JSON Values.
   2.  Changed the RDAP Conformance to be "redacted_level_0.2", which
       leveraged the extension identifier as a prefix along with
       "_level_" and a pointed version number.  The version number will
       become "1.0" once the draft passes WGLC.
   3.  Added the Redaction by Replacement Value Method.

A.5.  Change from 04 to 05

   1.  Update the RDAP Extensions Registry entries to include the
       identifier that is used for the RDAP conformance value and to
       include the "redacted" prefix indentifier to use for the JSON
       response member.
   2.  Changed the RDAP Conformance to be "redacted_level_0_3", which is
       registered in the RDAP Extensions Registry.  The RDAP Conformance
       value will become "redacted_level_1" once the draft passes WGLC.

A.6.  Change from 05 to 06

   1.  Fixed a couple nits.
   2.  Updated the Redaction by Replacement Value Method email web form
       examples to use the "contact-uri" jCard property of RFC 8605.

A.7.  Change from 06 to 07

   1.  Added the optional replacementPath child member for use with the
       Redaction by Replacement Value Method.

A.8.  Change from 07 to 08

   1.  Updates based on the Rick Wilhelm feedback:
       1.  Updated the definition of a redacted RDAP field in the
           Introduction section.
       2.  Updated the reference to three methods instead of two in the
           Redaction Methods section.
       3.  Created a new paragraph for the example in the Redaction by
           Removal Method section.
       4.  Explicity specified one or more redacted fields for inclusion
           of the "redacted" member in the "redacted" Member section.
       5.  Updated the description of the "method" member in the
           "redacted" Member section.

Authors' Addresses
   James Gould
   VeriSign, Inc.
   12061 Bluemont Way
   Reston, VA 20190
   United States of America
   Email: jgould@verisign.com
   URI:   http://www.verisigninc.com

   David Smith
   VeriSign, Inc.
   12061 Bluemont Way
   Reston, VA 20190
   United States of America
   Email: dsmith@verisign.com
   URI:   http://www.verisigninc.com

   Jody Kolker
   GoDaddy Inc.
   14455 N. Hayden Rd. #219
   Scottsdale, AZ 85260
   United States of America
   Email: jkolker@godaddy.com
   URI:   http://www.godaddy.com

   Roger Carney
   GoDaddy Inc.
   14455 N. Hayden Rd. #219
   Scottsdale, AZ 85260
   United States of America
   Email: rcarney@godaddy.com
   URI:   http://www.godaddy.com