--- 1/draft-ietf-lamps-eai-addresses-12.txt 2017-08-30 11:13:14.348853294 -0700 +++ 2/draft-ietf-lamps-eai-addresses-13.txt 2017-08-30 11:13:14.372853870 -0700 @@ -1,19 +1,19 @@ LAMPS A. Melnikov, Ed. Internet-Draft Isode Ltd Intended status: Standards Track W. Chuang, Ed. -Expires: December 31, 2017 Google, Inc. - June 29, 2017 +Expires: March 3, 2018 Google, Inc. + August 30, 2017 Internationalized Email Addresses in X.509 certificates - draft-ietf-lamps-eai-addresses-12 + draft-ietf-lamps-eai-addresses-13 Abstract This document defines a new name form for inclusion in the otherName field of an X.509 Subject Alternative Name and Issuer Alternative Name extension that allows a certificate subject to be associated with an Internationalized Email Address. Status of This Memo @@ -23,21 +23,21 @@ 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 http://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 December 31, 2017. + This Internet-Draft will expire on March 3, 2018. Copyright Notice Copyright (c) 2017 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -65,74 +65,76 @@ Appendix B. Example of SmtpUTF8Name . . . . . . . . . . . . . . 10 Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 1. Introduction [RFC5280] defines the rfc822Name subjectAltName name type for representing [RFC5321] email addresses. The syntax of rfc822Name is restricted to a subset of US-ASCII characters and thus can't be used to represent Internationalized Email addresses [RFC6531]. This - document calls for a new otherName variant to represent - Internationalized Email addresses. In addition this document calls - for all email address domains in X.509 certificates to conform to - IDNA2008 [RFC5890]. + document defines a new otherName variant to represent + Internationalized Email addresses. In addition this document + requires all email address domains in X.509 certificates to conform + to IDNA2008 [RFC5890]. 2. Conventions Used in This Document 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 [RFC2119]. - The formal syntax use the Augmented Backus-Naur Form (ABNF) [RFC5234] - notation. + The formal syntax uses the Augmented Backus-Naur Form (ABNF) + [RFC5234] notation. 3. Name Definitions The GeneralName structure is defined in [RFC5280], and supports many different name forms including otherName for extensibility. This section specifies the SmtpUTF8Name name form of otherName, so that Internationalized Email addresses can appear in the subjectAltName of a certificate, the issuerAltName of a certificate, or anywhere else that GeneralName is used. id-on-SmtpUTF8Name OBJECT IDENTIFIER ::= { id-on 9 } SmtpUTF8Name ::= UTF8String (SIZE (1..MAX)) + -- SmtpUTF8Name conforms to Mailbox as specified + -- in Section 3.3 of RFC 6531. When the subjectAltName (or issuerAltName) extension contains an Internationalized Email address with a non-ASCII local-part, the address MUST be stored in the SmtpUTF8Name name form of otherName. The format of SmtpUTF8Name is defined as the ABNF rule SmtpUTF8Mailbox. SmtpUTF8Mailbox is a modified version of the Internationalized Mailbox which was defined in Section 3.3 of [RFC6531] which was itself derived from SMTP Mailbox from Section 4.1.2 of [RFC5321]. [RFC6531] defines the following ABNF rules for Mailbox whose parts are modified for internationalization: , , , , , and . In particular, was updated to also support UTF8-non-ascii. UTF8-non-ascii was described by Section 3.1 of [RFC6532]. Also, domain was extended to support - U-label, as defined in [RFC5890]. + U-labels, as defined in [RFC5890]. This document further refines Internationalized [RFC6531] Mailbox ABNF rules and calls this SmtpUTF8Mailbox. In SmtpUTF8Mailbox, labels that include non-ASCII characters MUST be stored in U-label (rather than A-label) [RFC5890] form. This restriction removes the need to determine which label encoding A- or U-label is present in the Domain. As per Section 2.3.2.1 of [RFC5890], U-label are encoded as UTF-8 [RFC3629] in Normalization Form C and other properties specified there. In SmtpUTF8Mailbox, domain labels that solely use ASCII characters (meaning not A- nor U-labels) SHALL use NR-LDH restrictions as specified by Section 2.3.1 of [RFC5890] and SHALL be restricted to lower case letters. NR-LDH stands for "Non-Reserved - Letters Digits Hyphen" and is the set LDH labels that do not have + Letters Digits Hyphen" and is the set of LDH labels that do not have "--" characters in the third and forth character position, which excludes "tagged domain names" such as A-labels. Consistent with the treatment of rfc822Name in [RFC5280], SmtpUTF8Name is an envelope and has no phrase (such as a common name) before it, has no comment (text surrounded in parentheses) after it, and is not surrounded by "<" and ">". Due to operational reasons to be described shortly and name constraint compatibility reasons described in Section 6, SmtpUTF8Name subjectAltName MUST only be used when the local part of the email @@ -154,36 +156,36 @@ conversion errors between alternate forms. This applies to SmtpUTF8Name and rfc822Name in subjectAltName, issuerAltName and anywhere else that these are used. 5. Matching of Internationalized Email Addresses in X.509 certificates In equivalence comparison with SmtpUTF8Name, there may be some setup work on one or both inputs depending of whether the input is already in comparison form. Comparing SmtpUTF8Names consists of a domain part step and a local-part step. The comparison form for local-parts - always is UTF-8. The comparison form for domain parts depends on + is always UTF-8. The comparison form for domain parts depends on context. While some contexts such as certificate path validation in [RFC5280] specify transforming domain to A-label (Section 7.5 and 7.2 in [RFC5280] as updated by [ID-lamps-rfc5280-i18n-update]), this document RECOMMENDS transforming to UTF-8 U-label instead. This reduces the likelihood of errors by reducing conversions as more implementations natively support U- label domains. Comparison of two SmtpUTF8Name is straightforward with no setup work needed. They are considered equivalent if there is an exact octet- for-octet match. Comparison with email addresses such as Internationalized email address or rfc822Name requires additional setup steps for domain part and local-part. The initial preparation for the email addresses is to remove any phrases or comments, as well as "<" and ">" present. This document calls for comparison of domain - labels that include non-ASCII characters be tranformed to U-label if + labels that include non-ASCII characters be transformed to U-label if not already in that form. The first step is to detect use of the A-label by using Section 5.1 of [RFC5891]. Next if necessary, transform any A-labels to U-labels Unicode as specified in Section 5.2 of [RFC5891]. Finally if necessary convert the Unicode to UTF-8 as specified in Section 3 of [RFC3629]. For ASCII NR-LDH labels, upper case letters are converted to lower case letters. In setup for SmtpUTF8Mailbox, the email address local-part MUST conform to the requirements of [RFC6530] and [RFC6531], including being a string in UTF-8 form. In particular, the local-part MUST NOT be transformed in any way, such as by doing case folding or @@ -325,70 +327,70 @@ 9.1. Normative References [ID-lamps-rfc5280-i18n-update] Housley, R., "Internationalization Updates to RFC 5280", June 2017, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, - DOI 10.17487/RFC2119, March 1997, - . + 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, . + 2003, . [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, - DOI 10.17487/RFC5234, January 2008, - . + DOI 10.17487/RFC5234, January 2008, . [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008, - . + . [RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321, - DOI 10.17487/RFC5321, October 2008, - . + DOI 10.17487/RFC5321, 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 Applications (IDNA): Protocol", RFC 5891, - DOI 10.17487/RFC5891, August 2010, - . + DOI 10.17487/RFC5891, August 2010, . [RFC6530] Klensin, J. and Y. Ko, "Overview and Framework for Internationalized Email", RFC 6530, DOI 10.17487/RFC6530, - February 2012, . + February 2012, . [RFC6531] Yao, J. and W. Mao, "SMTP Extension for Internationalized Email", RFC 6531, DOI 10.17487/RFC6531, February 2012, - . + . [RFC6532] Yang, A., Steele, S., and N. Freed, "Internationalized Email Headers", RFC 6532, DOI 10.17487/RFC6532, February - 2012, . + 2012, . 9.2. Informative References [RFC5912] Hoffman, P. and J. Schaad, "New ASN.1 Modules for the Public Key Infrastructure Using X.509 (PKIX)", RFC 5912, - DOI 10.17487/RFC5912, June 2010, - . + DOI 10.17487/RFC5912, June 2010, . Appendix A. ASN.1 Module The following ASN.1 module normatively specifies the SmtpUTF8Name structure. This specification uses the ASN.1 definitions from [RFC5912] with the 2002 ASN.1 notation used in that document. [RFC5912] updates normative documents using older ASN.1 notation. LAMPS-EaiAddresses-2016 { iso(1) identified-organization(3) dod(6)