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
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   described in the Simplified BSD License.

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].

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.

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.

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