The Authenticated Received Chain (ARC) Protocol
RFC 8617
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Type |
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RFC - Experimental
(July 2019; No errata)
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Last updated |
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2019-07-09
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Replaces |
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draft-andersen-arc
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Stream |
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IETF
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Formats |
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plain text
pdf
html
bibtex
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Reviews |
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WG state
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Submitted to IESG for Publication
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Document shepherd |
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Tim Wicinski
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Shepherd write-up |
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Show
(last changed 2018-12-13)
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| IESG |
IESG state |
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RFC 8617 (Experimental)
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Consensus Boilerplate |
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Yes
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Telechat date |
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Responsible AD |
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Alexey Melnikov
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Send notices to |
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Barry Leiba <barryleiba@computer.org>, Tim Wicinski <tjw.ietf@gmail.com>
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| IANA |
IANA review state |
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IANA OK - Actions Needed
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IANA action state |
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RFC-Ed-Ack
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Internet Engineering Task Force (IETF) K. Andersen
Request for Comments: 8617 LinkedIn
Category: Experimental B. Long, Ed.
ISSN: 2070-1721 Google
S. Blank, Ed.
Valimail
M. Kucherawy, Ed.
TDP
July 2019
The Authenticated Received Chain (ARC) Protocol
Abstract
The Authenticated Received Chain (ARC) protocol provides an
authenticated "chain of custody" for a message, allowing each entity
that handles the message to see what entities handled it before and
what the message's authentication assessment was at each step in the
handling.
ARC allows Internet Mail Handlers to attach assertions of message
authentication assessment to individual messages. As messages
traverse ARC-enabled Internet Mail Handlers, additional ARC
assertions can be attached to messages to form ordered sets of ARC
assertions that represent the authentication assessment at each step
of the message-handling paths.
ARC-enabled Internet Mail Handlers can process sets of ARC assertions
to inform message disposition decisions, identify Internet Mail
Handlers that might break existing authentication mechanisms, and
convey original authentication assessments across trust boundaries.
Andersen, et al. Experimental [Page 1]
RFC 8617 The ARC Protocol July 2019
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for examination, experimental implementation, and
evaluation.
This document defines an Experimental Protocol for the Internet
community. 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). Not
all documents approved by the IESG are candidates for any level of
Internet Standard; see 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/rfc8617.
Copyright Notice
Copyright (c) 2019 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.
Andersen, et al. Experimental [Page 2]
RFC 8617 The ARC Protocol July 2019
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. General Concepts . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Evidence . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2. Custody . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Chain of Custody . . . . . . . . . . . . . . . . . . . . 6
2.4. Validation of Chain of Custody . . . . . . . . . . . . . 6
3. Terminology and Definitions . . . . . . . . . . . . . . . . . 6
3.1. ARC Set . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2. Authenticated Received Chain (ARC) . . . . . . . . . . . 7
3.3. Internet Mail Handlers / Intermediaries . . . . . . . . . 7
3.4. Authentication Assessment . . . . . . . . . . . . . . . . 7
3.5. Signing vs. Sealing . . . . . . . . . . . . . . . . . . . 8
3.6. Sealer . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.7. Validator . . . . . . . . . . . . . . . . . . . . . . . . 8
3.8. Imported ABNF Tokens . . . . . . . . . . . . . . . . . . 8
3.9. Common ABNF Tokens . . . . . . . . . . . . . . . . . . . 8
4. Protocol Elements . . . . . . . . . . . . . . . . . . . . . . 9
4.1. ARC Header Fields . . . . . . . . . . . . . . . . . . . . 9
4.1.1. ARC-Authentication-Results (AAR) . . . . . . . . . . 9
4.1.2. ARC-Message-Signature (AMS) . . . . . . . . . . . . . 9
4.1.3. ARC-Seal (AS) . . . . . . . . . . . . . . . . . . . . 11
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