--- 1/draft-ietf-dmarc-eaiauth-02.txt 2019-02-27 19:13:42.267264687 -0800 +++ 2/draft-ietf-dmarc-eaiauth-03.txt 2019-02-27 19:13:42.283265074 -0800 @@ -1,19 +1,19 @@ Network Working Group J. Levine Internet-Draft Taughannock Networks -Updates: 6376, 7208, 7489 (if approved) February 22, 2019 +Updates: 6376, 7208, 7489 (if approved) February 27, 2019 Intended status: Standards Track -Expires: August 26, 2019 +Expires: August 31, 2019 E-mail Authentication for Internationalized Mail - draft-ietf-dmarc-eaiauth-02 + draft-ietf-dmarc-eaiauth-03 Abstract SPF (RFC7208), DKIM (RFC6376), and DMARC (RFC7489) enable a domain owner to publish e-mail authentication and policy information in the DNS. In internationalized e-mail, domain names can occur both as U-labels and A-labels. The Authentication-Results header reports the result of authentication checks made with SPF, DKIM, DMARC, and other schemes. This specification updates the SPF, DKIM, and DMARC specifications to clarify which form of internationalized domain @@ -28,21 +28,21 @@ 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 August 26, 2019. + This Internet-Draft will expire on August 31, 2019. 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 @@ -52,26 +52,26 @@ the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. General principles . . . . . . . . . . . . . . . . . . . . . 3 4. SPF and internationalized mail . . . . . . . . . . . . . . . 3 5. DKIM and internationalized mail . . . . . . . . . . . . . . . 4 - 6. DMARC and internationalized mail . . . . . . . . . . . . . . 4 + 6. DMARC and internationalized mail . . . . . . . . . . . . . . 5 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 8. Security Considerations . . . . . . . . . . . . . . . . . . . 5 9. Normative References . . . . . . . . . . . . . . . . . . . . 5 Appendix A. Change history . . . . . . . . . . . . . . . . . . . 6 - Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction SPF [RFC7208], DKIM [RFC6376], and DMARC [RFC7489] enable a domain owner to publish e-mail authentication and policy information in the DNS. SPF primarily publishes information about what host addresses are authorized to send mail for a domain. DKIM places cryptographic signatures on e-mail messages, with the validation keys published in the DNS. DMARC publishes policy information related to the domain in the From: header of e-mail messages. @@ -128,39 +128,48 @@ be either U-labels or A-labels. All U-labels MUST be converted to A-labels before being used for an SPF validation. This includes both the original DNS lookup, described in Section 3 of [RFC7208] and the macro expansion of domain-spec described in section 7. Section 4.3 of [RFC7208] states that all IDNs in an SPF DNS record MUST be A-labels; this rule is unchanged since any SPF record can be used to authorize either EAI or conventional mail. - SPF macros %s and %l expand the local-part of the sender's mailbox. - If the local-part contains non-ASCII characters, terms that include - %s or %l do not match anything. (Note that unlike U-labels, there is - no way to rewrite non-ASCII local parts into ASCII.) + SPF macros %{s} and %{l} expand the local-part of the sender's + mailbox. If the local-part contains non-ASCII characters, terms that + include %{s} or %{l} do not match anything. (Note that unlike + U-labels in domains, there is no way to rewrite non-ASCII local parts + into ASCII.) 5. DKIM and internationalized mail DKIM [RFC6376] specifies a message header that contains a cryptographic message signature and a DNS record that contains the validation key. Section 2.11 of [RFC6376] defines dkim-quoted-printable. Its definition is modified in internationalized messages so that non- ASCII UTF-8 characters need not be quoted. The ABNF for dkim-safe- - char in internationalized messages is replaced by the following: + char in internationalized messages is replaced by the following, + adding non-ASCII UTF-8 characters from [RFC3629]: - dkim-safe-char = %x21-3A / %x3C / %x3E-7E / %x80-FF + dkim-safe-char = %x21-3A / %x3C / %x3E-7E / + UTF8-2 / UTF8-3 / UTF8-4 ; '!' - ':', '<', '>' - '~', non-ASCII + UTF8-2 = + + UTF8-3 = + + UTF8-4 = + Section 3.5 of [RFC6376] states that IDNs in the d=, i=, and s= tags of a DKIM-Signature header MUST be encoded as A-labels. This rule is relaxed only for headers in internationalized messages [RFC6532] so IDNs SHOULD be represented as U-labels but MAY be A-labels. This provides improved consistency with other headers. The set of allowable characters in the local-part of an i= tag is extended as described in [RFC6532]. When computing or verifying the hash in a DKIM signature as described in section 3.7, the hash MUST use the domain name in the format it occurs in the header. @@ -201,20 +210,24 @@ document attempts to slightly mitigate some of them but does not, as far as the author knows, add any new ones. 9. 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, . + [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO + 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November + 2003, . + [RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322, DOI 10.17487/RFC5322, October 2008, . [RFC5890] Klensin, J., "Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework", RFC 5890, DOI 10.17487/RFC5890, August 2010, . [RFC5891] Klensin, J., "Internationalized Domain Names in @@ -248,20 +261,22 @@ Message Authentication, Reporting, and Conformance (DMARC)", RFC 7489, DOI 10.17487/RFC7489, March 2015, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Appendix A. Change history + 02 to 03 minor edits per Alexey + 01 to 02 update references 00 to 01 Relaxed canon, Typos 00 First WG version Author's Address John Levine Taughannock Networks