Internet DRAFT - draft-bonnell-lamps-rfc8398bis
draft-bonnell-lamps-rfc8398bis
Network Working Group A. Melnikov
Internet-Draft Isode Ltd
Obsoletes: 8398 (if approved) W. Chuang
Updates: 5280 (if approved) Google, Inc.
Intended status: Standards Track C. Bonnell
Expires: 8 January 2024 DigiCert
7 July 2023
Internationalized Email Addresses in X.509 Certificates
draft-bonnell-lamps-rfc8398bis-00
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.
This document updates RFC 5280 and obsoletes RFC 8398.
About This Document
This note is to be removed before publishing as an RFC.
The latest revision of this draft can be found at
https://CBonnell.github.io/draft-lamps-rfc8398-bis/draft-bonnell-
lamps-rfc8398bis.html. Status information for this document may be
found at https://datatracker.ietf.org/doc/draft-bonnell-lamps-
rfc8398bis/.
Discussion of this document takes place on the Limited Additional
Mechanisms for PKIX and SMIME (lamps) Working Group mailing list
(mailto:spasm@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/spasm/. Subscribe at
https://www.ietf.org/mailman/listinfo/spasm/.
Source for this draft and an issue tracker can be found at
https://github.com/CBonnell/draft-lamps-rfc8398-bis.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Melnikov, et al. Expires 8 January 2024 [Page 1]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
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 8 January 2024.
Copyright Notice
Copyright (c) 2023 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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Name Definitions . . . . . . . . . . . . . . . . . . . . . . 3
4. IDNA2008 . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Matching of Internationalized Email Addresses in X.509
Certificates . . . . . . . . . . . . . . . . . . . . . . 5
6. Name Constraints in Path Validation . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
8. Differences from RFC 8398 . . . . . . . . . . . . . . . . . . 8
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9
10.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. ASN.1 Module . . . . . . . . . . . . . . . . . . . . 10
Appendix B. Example of SmtpUTF8Mailbox . . . . . . . . . . . . . 12
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
Melnikov, et al. Expires 8 January 2024 [Page 2]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
1. Introduction
[RFC5280] defines the rfc822Name subjectAltName name type for
representing email addresses as described in [RFC5321]. 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 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 and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Name Definitions
The GeneralName structure is defined in [RFC5280] and supports many
different name forms including otherName for extensibility. This
section specifies the SmtpUTF8Mailbox 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-SmtpUTF8Mailbox OBJECT IDENTIFIER ::= { id-on 9 }
SmtpUTF8Mailbox ::= UTF8String (SIZE (1..MAX))
-- SmtpUTF8Mailbox conforms to Mailbox as specified
-- in Section 3.3 of RFC 6531. Additionally, all domain
-- labels included in the SmtpUTF8Mailbox value are
-- encoded as LDH-labels. In particular, domain labels
-- are not encoded as U-labels and instead are encoded
-- using their A-label representation.
When the subjectAltName (or issuerAltName) extension contains an
internationalized email address with a non-ASCII Local-part, the
address MUST be stored in the SmtpUTF8Mailbox name form of otherName.
The format of SmtpUTF8Mailbox is defined as the ABNF rule
SmtpUTF8Mailbox. SmtpUTF8Mailbox is a modified version of the
internationalized Mailbox that was defined in Section 3.3 of
[RFC6531], which was derived from Mailbox as defined in Section 4.1.2
of [RFC5321]. [RFC6531] defines the following ABNF rules for Mailbox
whose parts are modified for internationalization: Local-part, Dot-
string, Quoted-string, QcontentSMTP, Domain, and Atom. In
Melnikov, et al. Expires 8 January 2024 [Page 3]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
particular, Local-part 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-labels, as defined in [RFC5890].
This document further refines internationalized Mailbox ABNF rules as
described in [RFC6531] and calls this SmtpUTF8Mailbox. In
SmtpUTF8Mailbox, labels that include non-ASCII characters MUST be
stored in A-label (rather than U-label) form [RFC5890]. This
restriction reduces complexity for implementations of the
certification path validation algorithm defined in Section 6 of
[RFC5280]. In SmtpUTF8Mailbox, domain labels that solely use ASCII
characters (meaning neither A- nor U-labels) SHALL use NR-LDH
restrictions as specified by Section 2.3.1 of [RFC5890]. NR-LDH
stands for "Non-Reserved 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. To facilitate octet-for-octet comparisons of
SmtpUTF8Mailbox values, all NR-LDH and A-label labels which
constitute the domain part SHALL only be encoded with lowercase
letters. Consistent with the treatment of rfc822Name in [RFC5280],
SmtpUTF8Mailbox is an envelope Mailbox 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 ">"
characters.
Due to name constraint compatibility reasons described in Section 6,
SmtpUTF8Mailbox subjectAltName MUST NOT be used unless the Local-part
of the email address contains non-ASCII characters. When the Local-
part is ASCII, rfc822Name subjectAltName MUST be used instead of
SmtpUTF8Mailbox. This is compatible with legacy software that
supports only rfc822Name (and not SmtpUTF8Mailbox). The appropriate
usage of rfc822Name and SmtpUTF8Mailbox is summarized in Table 1
below.
SmtpUTF8Mailbox is encoded as UTF8String. The UTF8String encoding
MUST NOT contain a Byte-Order-Mark (BOM) [RFC3629] to aid consistency
across implementations, particularly for comparison.
+=================+=================+
| Local-part char | subjectAltName |
+=================+=================+
| ASCII-only | rfc822Name |
+-----------------+-----------------+
| non-ASCII | SmtpUTF8Mailbox |
+-----------------+-----------------+
Table 1: Email Address Formatting
Melnikov, et al. Expires 8 January 2024 [Page 4]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
Non-ASCII Local-part values may additionally include ASCII
characters.
4. IDNA2008
To facilitate comparison between email addresses, all email address
domains in X.509 certificates MUST conform to IDNA2008 [RFC5890] (and
avoid any "mappings" mentioned in that document). Use of non-
conforming email address domains introduces the possibility of
conversion errors between alternate forms. This applies to
SmtpUTF8Mailbox and rfc822Name in subjectAltName, issuerAltName, and
anywhere else that these are used.
5. Matching of Internationalized Email Addresses in X.509 Certificates
Equivalence comparisons with SmtpUTF8Mailbox consist of a domain part
step and a Local-part step. The comparison form for Local-parts is
always UTF-8. The comparison form for domain parts is always
performed with the LDH-label ([RFC5890]) encoding of the relevant
domain labels. The comparison of LDH-labels in domain parts reduces
complexity for implementations of the certification path validation
algorithm as defined Section 6 of [RFC5280] by obviating the need to
convert domain labels to their Unicode representation.
Comparison of two SmtpUTF8Mailboxes is straightforward with no setup
work needed. They are considered equivalent if there is an exact
octet-for-octet match.
Comparison of a SmtpUTF8Mailbox and rfc822Name will always fail.
SmtpUTF8Mailbox values SHALL contain a Local-part which includes one
or more non-ASCII characters, while rfc822Names only include ASCII
characters (including the Local-part). Thus, a SmtpUTF8Mailbox and
rfc822Name will never match.
Comparison of SmtpUTF8Mailbox values with internationalized email
addresses from other sources (such as received email messages, user
input, etc.) requires additional setup steps for domain part and
Local-part. The initial preparation for the email address to compare
with the SmtpUTF8Mailbox value is to remove any phrases, comments,
and "<" or ">" characters.
For the setup of the domain part, the following conversions SHALL be
performed:
Melnikov, et al. Expires 8 January 2024 [Page 5]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
1. Convert all labels which constitute the domain part that include
non-ASCII characters to A-labels if not already in that form. a.
Detect all U-labels present within the domain part using
Section 5.1 of [RFC5891]. b. Transform all detected U-labels
(Unicode) to A-labels (ASCII) as specified in Section 5.5 of
[RFC5891].
2. Convert all uppercase letters found within the NR-LDH and A-label
labels which constitute the domain part to lowercase letters.
For the setup of the Local-part, the Local-part MUST be verified to
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
normalization of any kind. The Local-part part of an
internationalized email address is already in UTF-8. Once setup is
complete, they are again compared octet-for-octet.
To summarize non-normatively, the comparison steps, including setup,
are:
1. If the domain contains U-labels, transform them to A-labels.
2. If any NR-LDH or A-label domain label in the domain part contains
uppercase letters, lowercase them.
3. Compare strings octet-for-octet for equivalence.
This specification expressly does not define any wildcard characters,
and SmtpUTF8Mailbox comparison implementations MUST NOT interpret any
characters as wildcards. Instead, to specify multiple email
addresses through SmtpUTF8Mailbox, the certificate MUST use multiple
subjectAltNames or issuerAltNames to explicitly carry any additional
email addresses.
6. Name Constraints in Path Validation
This section updates Section 4.2.1.10 of [RFC5280] to extend
rfc822Name name constraints to SmtpUTF8Mailbox subjectAltNames.
SmtpUTF8Mailbox-aware path validators will apply name constraint
comparison to the subject distinguished name and both forms of
subject alternative names rfc822Name and SmtpUTF8Mailbox.
Both rfc822Name and SmtpUTF8Mailbox subject alternative names
represent the same underlying email address namespace. Since legacy
CAs constrained to issue certificates for a specific set of domains
would lack corresponding UTF-8 constraints, [RFC8399BIS] updates,
modifies, and extends rfc822Name name constraints defined in
Melnikov, et al. Expires 8 January 2024 [Page 6]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
[RFC5280] to cover SmtpUTF8Mailbox subject alternative names. This
ensures that the introduction of SmtpUTF8Mailbox does not violate
existing name constraints. Since it is not valid to include non-
ASCII UTF-8 characters in the Local-part of rfc822Name name
constraints, and since name constraints that include a Local-part are
rarely, if at all, used in practice, name constraints updated in
[RFC8399BIS] allow the forms that represent all addresses at a host
or all mailboxes in a domain and deprecates rfc822Name name
constraints that represent a particular mailbox. That is, rfc822Name
constraints with a Local-part SHOULD NOT be used.
Constraint comparison with SmtpUTF8Mailbox subjectAltName starts with
the setup steps defined by Section 5. Setup converts the inputs of
the comparison (which is one of a subject distinguished name, an
rfc822Name, or an SmtpUTF8Mailbox subjectAltName, and one of an
rfc822Name name constraint) to constraint comparison form. For both
the name constraint and the subject, this will convert all A-labels
and NR-LDH labels to lowercase. Strip the Local-part and "@"
separator from each rfc822Name and SmtpUTF8Mailbox, leaving just the
domain part. After setup, this follows the comparison steps defined
in Section 4.2.1.10 of [RFC5280] as follows. If the resulting name
constraint domain starts with a "." character, then for the name
constraint to match, a suffix of the resulting subject alternative
name domain MUST match the name constraint (including the leading
".") octet-for-octet. If the resulting name constraint domain does
not start with a "." character, then for the name constraint to
match, the entire resulting subject alternative name domain MUST
match the name constraint octet-for-octet.
Certificate Authorities that wish to issue CA certificates with email
address name constraints MUST use rfc822Name subject alternative
names only. These MUST be IDNA2008-conformant names with no mappings
and with non-ASCII domains encoded in A-labels only.
The name constraint requirement with SmtpUTF8Mailbox subject
alternative name is illustrated in the non-normative diagram in
Figure 1. The first example (1) illustrates a permitted rfc822Name
ASCII-only host name name constraint and the corresponding valid
rfc822Name subjectAltName and SmtpUTF8Mailbox subjectAltName email
addresses. The second example (2) illustrates a permitted rfc822Name
host name name constraint with A-label, and the corresponding valid
rfc822Name subjectAltName and SmtpUTF8Mailbox subjectAltName email
addresses. Note that an email address with ASCII-only Local-part is
encoded as rfc822Name despite also having Unicode present in the
domain.
Melnikov, et al. Expires 8 January 2024 [Page 7]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
+-------------------------------------------------------------------+
| Root CA Cert |
+-------------------------------------------------------------------+
|
v
+-------------------------------------------------------------------+
| Intermediate CA Cert |
| Permitted |
| rfc822Name: elementary.school.example.com (1) |
| |
| rfc822Name: xn--pss25c.example.com (2) |
| |
+-------------------------------------------------------------------+
|
v
+-------------------------------------------------------------------+
| Entity Cert (w/explicitly permitted subjects) |
| SubjectAltName Extension |
| rfc822Name: student@elemenary.school.example.com (1) |
| SmtpUTF8Mailbox: u+5B66u+751F@elementary.school.example.com |
| (1) |
| |
| rfc822Name: student@xn--pss25c.example.com (2) |
| SmtpUTF8Mailbox: u+533Bu+751F@xn--pss25c.example.com (2) |
| |
+-------------------------------------------------------------------+
Figure 1: Name Constraints with SmtpUTF8Name and rfc822Name
7. Security Considerations
Use of SmtpUTF8Mailbox for certificate subjectAltName (and
issuerAltName) will incur many of the same security considerations as
in Section 8 in [RFC5280], but it introduces a new issue by
permitting non-ASCII characters in the email address Local-part.
This issue, as mentioned in Section 4.4 of [RFC5890] and in Section 4
of [RFC6532], is that use of Unicode introduces the risk of visually
similar and identical characters that can be exploited to deceive the
recipient. The former document references some means to mitigate
against these attacks. See [WEBER] for more background on security
issues with Unicode.
8. Differences from RFC 8398
This document obsoletes [RFC8398]. There are three major changes
defined in this specification which deviate from [RFC8398]:
Melnikov, et al. Expires 8 January 2024 [Page 8]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
1. In all cases, domain labels in mail addresses SHALL be encoded as
LDH-labels. In particular, domain names SHALL NOT be encoded
using U-Labels and instead use A-Labels.
2. To accommodate the first change listed above, the mail address
matching algorithm defined in Section 5 of [RFC8398] has been
modified to only accept domain labels that are encoded using
their A-label representation.
3. Additionally, the name constraints processing algorithm defined
in Section 6 of [RFC8398] has been modified to only accept domain
labels that are encoded using their A-label representation.
9. IANA Considerations
Update the document reference for the SmtpUTF8Mailbox otherName in
the "SMI Security for PKIX Other Name Forms" (1.3.6.1.5.5.7.8)
registry from RFC 8398 to this document.
10. References
10.1. 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,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/rfc/rfc3629>.
[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,
<https://www.rfc-editor.org/rfc/rfc5280>.
[RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
DOI 10.17487/RFC5321, October 2008,
<https://www.rfc-editor.org/rfc/rfc5321>.
[RFC5890] Klensin, J., "Internationalized Domain Names for
Applications (IDNA): Definitions and Document Framework",
RFC 5890, DOI 10.17487/RFC5890, August 2010,
<https://www.rfc-editor.org/rfc/rfc5890>.
Melnikov, et al. Expires 8 January 2024 [Page 9]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
[RFC5891] Klensin, J., "Internationalized Domain Names in
Applications (IDNA): Protocol", RFC 5891,
DOI 10.17487/RFC5891, August 2010,
<https://www.rfc-editor.org/rfc/rfc5891>.
[RFC6530] Klensin, J. and Y. Ko, "Overview and Framework for
Internationalized Email", RFC 6530, DOI 10.17487/RFC6530,
February 2012, <https://www.rfc-editor.org/rfc/rfc6530>.
[RFC6531] Yao, J. and W. Mao, "SMTP Extension for Internationalized
Email", RFC 6531, DOI 10.17487/RFC6531, February 2012,
<https://www.rfc-editor.org/rfc/rfc6531>.
[RFC6532] Yang, A., Steele, S., and N. Freed, "Internationalized
Email Headers", RFC 6532, DOI 10.17487/RFC6532, February
2012, <https://www.rfc-editor.org/rfc/rfc6532>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8398] Melnikov, A., Ed. and W. Chuang, Ed., "Internationalized
Email Addresses in X.509 Certificates", RFC 8398,
DOI 10.17487/RFC8398, May 2018,
<https://www.rfc-editor.org/rfc/rfc8398>.
[RFC8399BIS]
Housley, R., "Internationalization Updates to RFC 5280",
n.d., <https://datatracker.ietf.org/doc/draft-housley-
lamps-rfc8399bis/>.
10.2. 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,
<https://www.rfc-editor.org/rfc/rfc5912>.
[WEBER] Weber, C., "Attacking Software Globalization", March 2010,
<https://www.lookout.net/files/
Chris_Weber_Character%20Transformations%20v1.7_IUC33.pdf>.
Appendix A. ASN.1 Module
The following ASN.1 module normatively specifies the SmtpUTF8Mailbox
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.
Melnikov, et al. Expires 8 January 2024 [Page 10]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
LAMPS-EaiAddresses-2016
{ iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-lamps-eai-addresses-2016(92) }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
IMPORTS
OTHER-NAME
FROM PKIX1Implicit-2009
{ iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-implicit-02(59) }
id-pkix
FROM PKIX1Explicit-2009
{ iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-explicit-02(51) } ;
--
-- otherName carries additional name types for subjectAltName,
-- issuerAltName, and other uses of GeneralNames.
--
id-on OBJECT IDENTIFIER ::= { id-pkix 8 }
SmtpUtf8OtherNames OTHER-NAME ::= { on-SmtpUTF8Mailbox, ... }
on-SmtpUTF8Mailbox OTHER-NAME ::= {
SmtpUTF8Mailbox IDENTIFIED BY id-on-SmtpUTF8Mailbox
}
id-on-SmtpUTF8Mailbox OBJECT IDENTIFIER ::= { id-on 9 }
SmtpUTF8Mailbox ::= UTF8String (SIZE (1..MAX))
-- SmtpUTF8Mailbox conforms to Mailbox as specified
-- in Section 3.3 of RFC 6531. Additionally, all domain
-- labels included in the SmtpUTF8Mailbox value are
-- encoded as LDH-Labels. In particular, domain labels
-- are not encoded as U-Labels and instead are encoded
-- using their A-label representation.
END
Melnikov, et al. Expires 8 January 2024 [Page 11]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
Appendix B. Example of SmtpUTF8Mailbox
This non-normative example demonstrates using SmtpUTF8Mailbox as an
otherName in GeneralName to encode the email address
"u+533Bu+751F@xn--pss25c.example.com".
The hexadecimal DER encoding of the block is:
a02b0608 2b060105 05070809 a01f0c1d e58cbbe7 949f4078 6e2d2d70
73733235 632e6578 616d706c 652e636f 6d
The text decoding is:
0 43: [0] {
2 8: OBJECT IDENTIFIER '1 3 6 1 5 5 7 8 9'
12 31: [0] {
14 29: UTF8String 'u+533Bu+751F@xn--pss25c.example.com'
: }
: }
The example was encoded using Google's "der-ascii" program and the
above text decoding is an output of Peter Gutmann's "dumpasn1"
program.
Acknowledgments
TODO
Previous document:
Thank you to Magnus Nystrom for motivating this document. Thanks to
Russ Housley, Nicolas Lidzborski, Laetitia Baudoin, Ryan Sleevi, Sean
Leonard, Sean Turner, John Levine, and Patrik Falstrom for their
feedback. Also special thanks to John Klensin for his valuable input
on internationalization, Unicode, and ABNF formatting; to Jim Schaad
for his help with the ASN.1 example and his helpful feedback; and
especially to Viktor Dukhovni for helping us with name constraints
and his many detailed document reviews.
This document:
David Benjamin
Authors' Addresses
Alexey Melnikov
Isode Ltd
14 Castle Mews
Melnikov, et al. Expires 8 January 2024 [Page 12]
Internet-Draft I18N Mail Addresses in X.509 Certificate July 2023
Hampton
TW12 2NP
United Kingdom
Email: Alexey.Melnikov@isode.com
Wei Chuang
Google, Inc.
1600 Amphitheater Parkway
Mountain View, CA
United States of America
Email: weihaw@google.com
Corey Bonnell
DigiCert
Pittsburgh, PA
United States of America
Email: corey.bonnell@digicert.com
Melnikov, et al. Expires 8 January 2024 [Page 13]
