Internet DRAFT - draft-lvelvindron-tls-for-email
draft-lvelvindron-tls-for-email
Network Working Group L. Velvindron
Internet-Draft cyberstorm.mu
Updates: 8314 (if approved) S. Farrell
Intended status: Standards Track Trinity College Dublin
Expires: April 18, 2019 October 15, 2018
Use of TLS for Email Submission and Access
draft-lvelvindron-tls-for-email-02
Abstract
This specification updates current recommendation for the use of
Transport Layer Security (TLS) protocol to provide confidentiality of
email between a Mail User Agent (MUA) and a Mail Submission Server or
Mail Access Server. This document updates RFC8314.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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 April 18, 2019.
Copyright Notice
Copyright (c) 2018 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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Velvindron & Farrell Expires April 18, 2019 [Page 1]
Internet-Draft TLS For Email October 2018
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 2
3. Updates to RFC8314 . . . . . . . . . . . . . . . . . . . . . 2
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
6.1. Informative References . . . . . . . . . . . . . . . . . 4
6.2. Normative References . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
[RFC8314] defines the minimum recommended version for TLS as version
1.1. Due to the deprecation of TLS 1.1 in
[I-D.ietf-tls-oldversions-deprecate], this recommendation is no
longer valid. Therefore this document updates [RFC8314] so that the
minimum version for TLS is TLS 1.2.
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] when they
appear in ALL CAPS. These words may also appear in this document in
lower case as plain English words, absent their normative meanings.
3. Updates to RFC8314
OLD:
"4.1. Deprecation of Services Using Cleartext and TLS Versions Less
Than 1.1"
NEW:
"4.1. Deprecation of Services Using Cleartext and TLS Versions Less
Than 1.2"
OLD
"As soon as practicable, MSPs currently supporting Secure Sockets
Layer (SSL) 2.x, SSL 3.0, or TLS 1.0 SHOULD transition their users to
TLS 1.1 or later and discontinue support for those earlier versions
of SSL and TLS."
NEW:
Velvindron & Farrell Expires April 18, 2019 [Page 2]
Internet-Draft TLS For Email October 2018
"As soon as practicable, MSPs currently supporting Secure Sockets
Layer (SSL) 2.x, SSL 3.0, or TLS 1.0 SHOULD transition their users to
TLS 1.2 or later and discontinue support for those earlier versions
of SSL and TLS."
OLD:
In Section 4.1, the text should be revised from: "It is RECOMMENDED
that new users be required to use TLS version 1.1 or greater from the
start. However, an MSP may find it necessary to make exceptions to
accommodate some legacy systems that support only earlier versions of
TLS or only cleartext."
NEW:
"It is RECOMMENDED that new users be required to use TLS version 1.2
or greater from the start. However, an MSP may find it necessary to
make exceptions to accommodate some legacy systems that support only
earlier versions of TLS or only cleartext."
OLD:
" If, however, an MUA provides such an indication, it MUST NOT
indicate confidentiality for any connection that does not at least
use TLS 1.1 with certificate verification and also meet the minimum
confidentiality requirements associated with that account. "
NEW:
" If, however, an MUA provides such an indication, it MUST NOT
indicate confidentiality for any connection that does not at least
use TLS 1.2 with certificate verification and also meet the minimum
confidentiality requirements associated with that account. "
OLD
" MUAs MUST implement TLS 1.2 [RFC5246] or later. Earlier TLS and
SSL versions MAY also be supported, so long as the MUA requires at
least TLS 1.1 [RFC4346] when accessing accounts that are configured
to impose minimum confidentiality requirements. "
NEW:
" MUAs MUST implement TLS 1.2 [RFC5246] or later e.g TLS 1.3
[RFC8446]. Earlier TLS and SSL versions MAY also be supported, so
long as the MUA requires at least TLS 1.2 [RFC5246] when accessing
accounts that are configured to impose minimum confidentiality
requirements. "
Velvindron & Farrell Expires April 18, 2019 [Page 3]
Internet-Draft TLS For Email October 2018
OLD:
" The default minimum expected level of confidentiality for all new
accounts MUST require successful validation of the server's
certificate and SHOULD require negotiation of TLS version 1.2 or
greater. (Future revisions to this specification may raise these
requirements or impose additional requirements to address newly
discovered weaknesses in protocols or cryptographic algorithms. "
NEW:
" The default minimum expected level of confidentiality for all new
accounts MUST require successful validation of the server's
certificate and SHOULD require negotiation of TLS version 1.2 or
greater. (Future revisions to this specification may raise these
requirements or impose additional requirements to address newly
discovered weaknesses in protocols or cryptographic algorithms. "
4. IANA Considerations
None of the proposed measures have an impact on IANA.
5. Security Considerations
The purpose of this document is to document updated recommendations
for using TLS with Email services. Those recommendations are based
on [I-D.ietf-tls-oldversions-deprecate].
6. References
6.1. Informative References
[RFC4346] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.1", RFC 4346,
DOI 10.17487/RFC4346, April 2006,
<https://www.rfc-editor.org/info/rfc4346>.
6.2. Normative References
[I-D.ietf-tls-oldversions-deprecate]
Moriarty, K. and S. Farrell, "Deprecating TLSv1.0 and
TLSv1.1", draft-ietf-tls-oldversions-deprecate-00 (work in
progress), September 2018.
[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/info/rfc2119>.
Velvindron & Farrell Expires April 18, 2019 [Page 4]
Internet-Draft TLS For Email October 2018
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/info/rfc5246>.
[RFC8314] Moore, K. and C. Newman, "Cleartext Considered Obsolete:
Use of Transport Layer Security (TLS) for Email Submission
and Access", RFC 8314, DOI 10.17487/RFC8314, January 2018,
<https://www.rfc-editor.org/info/rfc8314>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
Authors' Addresses
Loganaden Velvindron
cyberstorm.mu
88 Avenue De Plevitz Roches Brunes
Rose Hill 71259
Mauritius
Phone: +230 59762817
Email: loganaden@gmail.com
Stephen Farrell
Trinity College Dublin
Dublin 2
Ireland
Phone: +353-1-896-2354
Email: stephen.farrell@cs.tcd.ie
Velvindron & Farrell Expires April 18, 2019 [Page 5]
