Internet Engineering Task Force R. Roda, Ed. Internet-Draft 5 December 2023 Intended status: Informational Expires: 7 June 2024 An HTTP Status Code to Report Requester Impairment draft-richardroda-420requesterimpaired-00 Abstract This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when an operation or resource is denied due to requester impairment. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 7 June 2024. Copyright Notice Copyright (c) 2023 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Roda Expires 7 June 2024 [Page 1] Internet-Draft HTTP Requester Impairment Status Code December 2023 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. 420 Requester Impaired . . . . . . . . . . . . . . . . . . . 2 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 5.1. Normative References . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when a request is denied because the requester is impaired. This request code may be used to provide visibility in cases where one or more valid requests create a dangerous situation, there is a pattern of erratic requests with the potential for danger, or the requester is otherwise detected as impaired. Network-controlled devices are being used for beneficial but potentially dangerous activities such as construction and remote surgery. Identifying requester impairment is important for both accurately assessing the risk a given requester presents and preventing damage caused by a high-risk requester. 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. 420 Requester Impaired The status code 420 indicates that the server is denying the request as a consequence of evidence of requester impairment. The server in question might not be an origin server. An intermediate proxy closer to the requester may be in a better position to assess potential requester impairment. Such a proxy may refuse to forward the request and respond with this error code. Roda Expires 7 June 2024 [Page 2] Internet-Draft HTTP Requester Impairment Status Code December 2023 There is no requirement that the requester be human. Certain AI systems can exhibit behaviors such as giving hallucinated, incorrect, and differing answers for a given input. Given the speed at which such AI operates, it is no less important to detect the impairment of AI requesters as human requesters. This response code provides greater visibility for requester impairment than the 403 Forbidden code. Such visibility will aid network monitoring for impaired requesters. This will improve remediation and risk assessment of possibly impaired requesters. Such responses MAY include the inputs or evidence used to determine impairment, but SHOULD NOT reveal information that a requester can use to evade impairment detection. A 420 response is non-cacheable by default, i.e., unless otherwise indicated by the method definition or explicit cache controls; see [RFC9111]. AI An artificial intelligence system that is capable of making independent decisions without direct human control. proxy A server with a primary purpose of forwarding requests to other servers to process. HTTP/1.1 420 Requester Impaired Content-Type: text/html Requester Impaired

Requester Impaired

This request is denied due to detection of impairment.

Figure 1: Example Response 3. IANA Considerations IANA is asked to update the HTTP Status Codes Registry with the following entry: * Code: 420 Roda Expires 7 June 2024 [Page 3] Internet-Draft HTTP Requester Impairment Status Code December 2023 * Description: Requester Impaired * Specification: This RFC 4. Security Considerations If the requesters are identifiable because they have been authenticated and authorized, their authorization SHOULD be revoked until they have been determined not to be impaired. If the requesters are unauthenticated, further requests SHOULD be denied until it can be determined that no impaired requesters are using the system. 5. References 5.1. 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, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC9111] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Caching", STD 98, RFC 9111, DOI 10.17487/RFC9111, June 2022, . Author's Address Richard Roda (editor) Email: richard_roda@hotmail.com URI: https://www.linkedin.com/in/richardroda/ Roda Expires 7 June 2024 [Page 4]