Message Queuing Telemetry Transport (MQTT)-TLS profile of Authentication and Authorization for Constrained Environments (ACE) Framework
draft-ietf-ace-mqtt-tls-profile-07
ACE Working Group C. Sengul
Internet-Draft Brunel University
Intended status: Standards Track A. Kirby
Expires: February 26, 2021 Oxbotica
P. Fremantle
University of Portsmouth
August 25, 2020
Message Queuing Telemetry Transport (MQTT)-TLS profile of Authentication
and Authorization for Constrained Environments (ACE) Framework
draft-ietf-ace-mqtt-tls-profile-07
Abstract
This document specifies a profile for the ACE (Authentication and
Authorization for Constrained Environments) framework to enable
authorization in an Message Queuing Telemetry Transport (MQTT)-based
publish-subscribe messaging system. Proof-of-possession keys, bound
to OAuth2.0 access tokens, are used to authenticate and authorize
MQTT Clients. The protocol relies on TLS for confidentiality and
MQTT server (broker) authentication.
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 February 26, 2021.
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
Sengul, et al. Expires February 26, 2021 [Page 1]
Internet-Draft MQTT-TLS profile of ACE August 2020
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 . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.2. ACE-Related Terminology . . . . . . . . . . . . . . . . . 4
1.3. MQTT-Related Terminology . . . . . . . . . . . . . . . . 5
2. Authorizing Connection Requests . . . . . . . . . . . . . . . 7
2.1. Client Token Request to the Authorization Server (AS) . . 8
2.2. Client Connection Request to the Broker (C) . . . . . . . 9
2.2.1. Client-Server Authentication over TLS and MQTT . . . 9
2.2.2. authz-info: The Authorization Information Topic . . . 10
2.2.3. Transporting Access Token Inside the MQTT CONNECT . . 11
2.2.4. Authentication Using AUTH Property . . . . . . . . . 14
2.2.4.1. Proof-of-Possession Using a Challenge from the
TLS session . . . . . . . . . . . . . . . . . . . 14
2.2.4.2. Proof-of-Possession via Broker-generated
Challenge/Response . . . . . . . . . . . . . . . 14
2.2.5. Token Validation . . . . . . . . . . . . . . . . . . 15
2.2.6. The Broker's Response to Client Connection Request . 16
2.2.6.1. Unauthorised Request: Authorisation Server
Discovery . . . . . . . . . . . . . . . . . . . . 16
2.2.6.2. Authorisation Success . . . . . . . . . . . . . . 16
3. Authorizing PUBLISH and SUBSCRIBE Messages . . . . . . . . . 16
3.1. PUBLISH Messages from the Publisher Client to the Broker 17
3.2. PUBLISH Messages from the Broker to the Subscriber
Clients . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.3. Authorizing SUBSCRIBE Messages . . . . . . . . . . . . . 18
4. Token Expiration and Reauthentication . . . . . . . . . . . . 18
5. Handling Disconnections and Retained Messages . . . . . . . . 19
6. Reduced Protocol Interactions for MQTT v3.1.1 . . . . . . . . 19
6.1. Token Transport . . . . . . . . . . . . . . . . . . . . . 20
6.2. Handling Authorization Errors . . . . . . . . . . . . . . 21
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
8. Security Considerations . . . . . . . . . . . . . . . . . . . 23
Show full document text