Internet Engineering Task Force (IETF) M. Kucherawy
Request for Comments: 6577 Cloudmark, Inc.
Updates: 5451 March 2012
Category: Standards Track
ISSN: 2070-1721
Authentication-Results Registration Update for
Sender Policy Framework (SPF) Results
Abstract
This memo updates the registry of authentication method results in
Authentication-Results: message header fields, correcting a
discontinuity between the original registry creation and the Sender
Policy Framework (SPF) specification.
This memo updates RFC 5451.
Status of This Memo
This is an Internet Standards Track document.
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). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6577.
Copyright Notice
Copyright (c) 2012 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Kucherawy Standards Track [Page 1]RFC 6577 Auth-Results SPF Erratum March 2012
Table of Contents
1. Introduction ....................................................2
2. Keywords ........................................................2
3. New 'fail' Definition ...........................................2
4. IANA Considerations .............................................2
4.1. Addition of 'Status' Columns ...............................3
4.2. Update to Result Names .....................................3
5. Security Considerations .........................................3
6. References ......................................................4
6.1. Normative References .......................................4
6.2. Informative References .....................................4
Appendix A. Examples in RFC 5451 ...................................5
Appendix B. Acknowledgements .......................................5
1. Introduction
[AUTHRES] defined a new header field for electronic mail messages
that presents the results of a message authentication effort in a
machine-readable format. That Request for Comments created a
registry of results for a few message authentication mechanisms, one
of which was the Sender Policy Framework [SPF]. The registry
contains one entry that is inconsistent with the latter
specification, which was noted in an erratum [ERR2617] filed with the
RFC Editor. This memo updates the IANA registries accordingly.
2. Keywords
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [KEYWORDS].
3. New 'fail' Definition
The new "fail" result, replacing the existing "hardfail" result for
[SPF] (and thus also for [SENDER-ID]) has the same definition for
"hardfail" that was used in Section 2.4.2 of [AUTHRES], namely:
This client is explicitly not authorized to inject or relay mail
using the sender's DNS domain.
4. IANA Considerations
This section enumerates requested actions of IANA, per [IANA].
Kucherawy Standards Track [Page 2]RFC 6577 Auth-Results SPF Erratum March 2012
4.1. Addition of 'Status' Columns
IANA has amended the Email Authentication Methods and Email
Authentication Result Names registries, both in the Email
Authentication Parameters group, by adding to each a column called
"Status" that will indicate for each entry its current status. Legal
values for these columns are as follows:
active: The entry is in current use.
deprecated: The entry is no longer in current use.
New registrations to either table MUST specify one of these values.
All existing entries, except as specified below, are to be noted as
"active" as of publication of this memo.
4.2. Update to Result Names
[AUTHRES] listed "hardfail" as the result to be used when a message
fails an [SPF] evaluation. However, this latter specification used
the string "fail" to denote such failures.
Therefore, IANA has marked "hardfail" in the Email Authentication
Result Names registry as "deprecated" and amended the "fail" entry as
follows:
Code: fail
Defined: [AUTHRES]
Auth Method: spf, sender-id
Meaning: [this memo] Section 3
Status: active
5. Security Considerations
This memo corrects a registry error. It is possible that older
implementations will not recognize or use the corrected entry. Thus,
implementers are advised to support both result strings for some
period of time. However, it is known that some implementations are
already using the SPF-defined result string.
Kucherawy Standards Track [Page 3]
RFC 6577 Auth-Results SPF Erratum March 2012
6. References
6.1. Normative References
[AUTHRES] Kucherawy, M., "Message Header Field for Indicating
Message Authentication Status", RFC 5451, April 2009.
[ERR2617] "RFC Errata", Errata ID 2617, RFC 5451,
<http://www.rfc-editor.org>.
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
6.2. Informative References
[ERR2818] "RFC Errata", Errata ID 2818, RFC 5451,
<http://www.rfc-editor.org>.
[IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[SENDER-ID] Lyon, J. and M. Wong, "Sender ID: Authenticating
E-Mail", RFC 4406, April 2006.
[SPF] Wong, M. and W. Schlitt, "Sender Policy Framework (SPF)
for Authorizing Use of Domains in E-Mail, Version 1",
RFC 4408, April 2006.
Kucherawy Standards Track [Page 4]RFC 6577 Auth-Results SPF Erratum March 2012
Appendix A. Examples in RFC 5451
It should be noted that this update also applies to the examples in
[AUTHRES], specifically the one in Appendix B.5. The error there
[ERR2818] is not corrected by this update, which only deals with the
normative portions of that specification and the related IANA
registrations. However, it is assumed one could easily see what
needs to be corrected there.
Corrected examples will be included in a full update to [AUTHRES] at
some future time.
Appendix B. Acknowledgements
The author wishes to acknowledge the following for their review and
constructive criticism of this proposal: S. Moonesamy, Scott
Kitterman.
Author's Address
Murray S. Kucherawy
Cloudmark, Inc.
128 King St., 2nd Floor
San Francisco, CA 94107
US
Phone: +1 415 946 3800
EMail: msk@cloudmark.com
Kucherawy Standards Track [Page 5]
