Internet-Draft | Redacted Fields in RDAP | August 2022 |
Gould, et al. | Expires 17 February 2023 | [Page] |
This document describes an RDAP extension for explicitly identifying redacted RDAP response fields, using JSONPath as the default expression language.¶
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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 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].¶
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.¶
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 three categories defined in the following sub-sections.¶
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:¶
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.¶
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:¶
An example of the "redacted" member for the redacted "fn" jCard property value, which is array position 3:¶
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:¶
An example of the "redacted" member for the redacted registrant "email" jCard property 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:¶
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:¶
RDAP responses that contain values described in this document MUST indicate conformance with this specification by including an "rdapConformance" ([RFC9083]) value of "redacted". The "redacted" extension identifier is described in Section 6.1.¶
Example "rdapConformance" member with the redacted extension:¶
The "redacted" member MUST be added to the RDAP response when there 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:¶
OPTIONAL redaction method used; with one of the following values:¶
The default value is "removal" when not provided.¶
Example unredacted version of an RDAP lookup response:¶
Example redacted version of an RDAP lookup response:¶
Example unredacted version of an RDAP search response:¶
Example redacted version of an RDAP search response:¶
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:¶
IANA is requested to register the following value in the RDAP Extensions 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:¶
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".¶
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¶
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.¶
The authors wish to thank the following persons for their feedback and suggestions: Marc Blanchet, Scott Hollenbeck, Mario Loffredo, Gustavo Lozano, and Rick Wilhelm.¶
Updates based on the Gustavo Lozano feedback:¶
Updates based on the Marc Blanchet feedback:¶
Updates based on the Mario Loffredo feedback:¶
Updates to add support for RDAP search responses:¶
Updates based on the Rick Wilhelm feedback:¶