Internet Engineering Task Force K. Moriarty
Internet-Draft Dell EMC
Updates: [[List TBD]] (if approved) S. Farrell
Intended status: Standards Track Trinity College Dublin
Expires: January 26, 2019 July 25, 2018
Deprecating TLSv1.0 and TLSv1.1
draft-moriarty-tls-oldversions-diediedie-01
Abstract
This document [if approved] formally deprecates Transport Layer
Security (TLS) versions 1.0 [RFC2246] and 1.1 [RFC4346] and moves
these documents to the historic state. These versions lack support
for current and recommended cipher suites, and various government and
industry profiiles of applications using TLS now mandate avoiding
these old TLS versions. TLSv1.2 has been the recommended version for
IETF protocols since 2008, providing sufficient time to transition
away from older versions. Products having to support older versions
increase the attack surface unnecessarily and increase opportunities
for misconfigurations. Supporting these older versions also requires
additional effort for library and product maintenance.
This document updates the backward compatibility sections of TLS RFCs
[[list TBD]] to prohibit fallback to TLSv1.0 and TLSv1.1. This
document also updates RFC 7525.
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 January 26, 2019.
Moriarty & Farrell Expires January 26, 2019 [Page 1]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. Support for Deprecation . . . . . . . . . . . . . . . . . . . 4
3. Removing Support . . . . . . . . . . . . . . . . . . . . . . 5
4. Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Web . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2. Mail . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Operating Systems . . . . . . . . . . . . . . . . . . . . 7
4.4. Enterprise Networks . . . . . . . . . . . . . . . . . . . 7
5. SHA-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Do Not Use TLSv1.0 . . . . . . . . . . . . . . . . . . . . . 8
7. Do Not Use TLSv1.1 . . . . . . . . . . . . . . . . . . . . . 9
8. Do Not Use SHA-1 in TLSv1.2 . . . . . . . . . . . . . . . . . 9
9. Updates to RFC7525 . . . . . . . . . . . . . . . . . . . . . 9
10. Security Considerations . . . . . . . . . . . . . . . . . . . 10
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
13.1. Normative References . . . . . . . . . . . . . . . . . . 11
13.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
[[Text in double-square brackets is intended to be fixed as the draft
evolves. You've seen that we need to figure out the list of RFCs
that this'd update in the abstract. There is a repo for this at:
https://github.com/sftcd/tls-oldversions-diediedie - PRs (on the xml
file) are welcome there.]]
Moriarty & Farrell Expires January 26, 2019 [Page 2]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
Transport Layer Security (TLS) versions 1.0 [RFC2246] and 1.1
[RFC4346] were superceded by TLSv1.2 [RFC5246] in 2008, which has now
itself been superceded by TLSv1.3 [I-D.ietf-tls-tls13]. It is
therefore timely to further deprecate these old versions. The
expection is that TLSv1.2 will continue to be used for many years
alongside TLSv1.3.
TLSv1.1 and TLSv1.0 are also actively being deprecated in accordance
with guidance from government agencies (e.g. NIST SP 80052r2
[NIST800-52r2]) and industry consortia such as the Payment Card
Industry Association (PCI) [PCI-TLS1].
The primary technical reasons for deprecating these versions include:
o They require implementation of older cipher suites that are no
longer desirable for cryptographic reasons, e.g. TLSv1.0 makes
TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA mandatory to implement
o Lack of support for current recommended cipher suites, especially
using AEAD ciphers which are not supported prior to TLS 1.2.
Note: registry entries for no-longer-desirable ciphersuites remain
in the registries, but many TLS registries are being updated
through [I-D.ietf-tls-iana-registry-updates] which denotes such
entries as "not recommended."
o Integrity of the handshake depends on SHA-1 hash
o Authentication of the peers depends on SHA-1 signatures
o Support for four protocol versions increases the likelihood of
misconfiguration
o At least one widely-used library has plans to drop TLSv1.1 and
TLSv1.0 support in upcoming releases; products using such
libraries would need to use older versions of the libraries to
support TLSv1.0 and TLSv1.1, which is clearly undesirable
Deprecation of these versions is intended to assist developers as
additional justification to no longer support older TLS versions and
to migrate to a minimum of TLSv1.2. Deprecation also assists product
teams with phasing out support for the older versions to reduce the
attack surface and the scope of maintenance for protocols in their
offerings.
[[This draft is being written now so that the TLS WG chairs can just
hit the "publication requested" button as soon as there is WG
consensus to deprecate these ancient versions of TLS. The authors
however think that deprecation now is timely.]]
Moriarty & Farrell Expires January 26, 2019 [Page 3]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
1.1. Terminology
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.
2. Support for Deprecation
Industry has actively followed guidance provided by NIST and the PCI
Council to deprecate TLSv1.0 and TLSv1.1 by June 30, 2018. TLSv1.2
should remain a minimum baseline for TLS support at this time.
Specific details on attacks against TLSv1.0 and TLSv1.1 as well as
their mitigations are provided in NIST SP800-52r2 [NIST800-52r2], RFC
7457 [RFC7457] and other referenced RFCs. Although the attacks have
been mitigated, if support is dropped for future library releases for
these versions, it is unlikely attacks found going forward will be
mitigated in older library releases.
NIST for example have provided the following rationale, copied with
permission from NIST SP800-52r2 [NIST800-52r2], section 1.2 "History
of TLS" (with references changed for RFC formating).
TLS 1.1, specified in [RFC4346], was developed to address
weaknesses discovered in TLS 1.0, primarily in the areas of
initialization vector selection and padding error processing.
Initialization vectors were made explicit to prevent a certain
class of attacks on the Cipher Block Chaining (CBC) mode of
operation used by TLS. The handling of padding errors was altered
to treat a padding error as a bad message authentication code,
rather than a decryption failure. In addition, the TLS 1.1 RFC
acknowledges attacks on CBC mode that rely on the time to compute
the message authentication code (MAC). The TLS 1.1 specification
states that to defend against such attacks, an implementation must
process records in the same manner regardless of whether padding
errors exist. Further implementation considerations for CBC modes
(which were not included in RFC4346 [RFC4346]) are discussed in
Section 3.3.2.
TLS 1.2, specified in RFC5246 [RFC5246], made several
cryptographic enhancements, particularly in the area of hash
functions, with the ability to use or specify the SHA-2 family
algorithms for hash, MAC, and Pseudorandom Function (PRF)
computations. TLS 1.2 also adds authenticated encryption with
associated data (AEAD) cipher suites.
Moriarty & Farrell Expires January 26, 2019 [Page 4]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
TLS 1.3, specified in TLSv1.3 [I-D.ietf-tls-tls13], represents a
significant change to TLS that aims to address threats that have
arisen over the years. Among the changes are a new handshake
protocol, a new key derivation process that uses the HMAC-based
Extract-and-Expand Key Derivation Function (HKDF), and the removal
of cipher suites that use static RSA or DH key exchanges, the CBC
mode of operation, or SHA-1. The list of extensions that can be
used with TLS 1.3 has been reduced considerably.
The Canadian government treasury board have mandated that these old
versions of TLS not be used. [Canada]
3. Removing Support
[[This section can be removed upon publication - or maybe keep it?]]
Support for TLSv1.0 has been removed by the July 2018 PCI deadline
from the following standards, products, and services:
o 3GPP 5G
o Amazon Elastic Load Balancing [Amazon]
o CloudFare [CloudFlare]
o Digicert [Digicert]
o GitHub [GIT]
o KeyCDN [KeyCDN]
o PayPal [paypal]
o Stripe [stripe]
o [[Numerous web sites...]]
Many web sites have taken the action of including the deprecation of
TLSv1.1 into their plans for deprecating TLSv1.0 for the PCI council
deadline. Support for TLSv1.1 has been removed by the July 2018 PCI
deadline from the following standards, products, and services:
o 3GPP 5G Release 16
o Amazon Elastic Load Balancing [Amazon]
o CloudFare [CloudFlare]
o GitHub [GIT]
o PayPal [paypal]
o Stripe [stripe]
o [[Numerous web sites...]]
4. Usage
[[This section can be removed upon publication - or maybe keep it?]]
Moriarty & Farrell Expires January 26, 2019 [Page 5]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
4.1. Web
Usage statistics for TLSv1.0 and TLSv1.1 on the public web vary, but
have been in general very low and declined further with the impending
PCI deadline to migrate off of TLSv1.0 by June 30, 2018. As of
January 2018, [StackExchange] quoted 4 percent of browsers using
TLSv1.0.
The number of websites supporting TLS 1.2 is still growing (+0.4%),
and has reached 92% according to sslpulse as of June 19, 2018.
[SSLpulse] Deprecating TLS 1.0 and TLS 1.1 will thus not have a major
impact on browser or web server implementations.
Figure 1 presents statistics for use of TLS versions in the web.
+----------------+----------+------+-------+-------+-------+-------+
| Name/Ref | Date | SSLv3|TLSv1.0|TLSv1.1|TLSv1.2|TLSv1.3|
+----------------+----------+------+-------+-------+-------+-------+
! Alexa [1] | 20180226 | - | 2.0 | <0.1 | 97.9 | - |
| Cloudflare [2] | 20180518 | 0.0 | 9.3 | 0.2 | 84.9 | 5.5 |
| Firefox [3] | 20180709 | - | 1.0 | - | 94.0 | 5.0 |
| Chrome [4] | 20180711 | - | 0.4 | <0.1 | - | - |
+----------------+----------+------+-------+-------+-------+-------+
[1] https://scotthelme.co.uk/alexa-top-1-million-analysis-february-2018/
[2] https://www.ietf.org/mail-archive/web/tls/current/msg26578.html
[3] https://www.ietf.org/mail-archive/web/tls/current/msg26575.html
[4] https://www.ietf.org/mail-archive/web/tls/current/msg26620.html
Figure 1: Web Statistics
4.2. Mail
E-Mail uses TLS for SMTP, submission (port 587), POP/POP3 and IMAP.
Typically email deployments lag public web deployments in terms of
the rate of adoption of new TLS versions. Figure 2 presents
statistics for use of TLS versions in the email applications.
Moriarty & Farrell Expires January 26, 2019 [Page 6]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
+----------------+----------+------+-------+-------+-------+-------+
| Name/Ref | Date | SSLv3|TLSv1.0|TLSv1.1|TLSv1.2|TLSv1.3|
+----------------+----------+------+-------+-------+-------+-------+
| Clusters [1] | 20180316 | <0.1 | 10.6 | <0.1 | 89.3 | - |
| TLSA [2] | 20180710 | - | 1.4 | 0.1 | 98.5 | - |
| UK-ESP [3] | 20180710 | - | 19.9 | <0.1 | - | - |
+----------------+----------+------+-------+-------+-------+-------+
[1] https://eprint.iacr.org/2018/299
[2] https://www.ietf.org/mail-archive/web/tls/current/msg26603.html
[3] https://www.ietf.org/mail-archive/web/tls/current/msg26603.html
Figure 2: Mail Statistics
4.3. Operating Systems
Figure 3 presents statistics for use of TLS versions in operating
systems.
+----------------+----------+------+-------+-------+-------+-------+
| Name/Ref | Date | SSLv3|TLSv1.0|TLSv1.1|TLSv1.2|TLSv1.3|
+----------------+----------+------+-------+-------+-------+-------+
| Windows cli [1]| 20180709 | - | >10.0 | ~0.3 | - | - |
| Windows svr [1]| 20180709 | - | ~1.5 | ~0.0 | - | - |
| Apple [2] | 20180709 | - | 0.4 | - | 99.6 | - |
+----------------+----------+------+-------+-------+-------+-------+
[1] https://www.ietf.org/mail-archive/web/tls/current/msg26577.html
[2] https://www.ietf.org/mail-archive/web/tls/current/msg26634.html
Figure 3: Operating System Statistics
4.4. Enterprise Networks
Figure 4 presents statistics for use of TLS versions in the
enterprise networks. The tcd.ie numbers below were the result of a
student project and need further validation.
+----------------+----------+------+-------+-------+-------+-------+
| Name/Ref | Date | SSLv3|TLSv1.0|TLSv1.1|TLSv1.2|TLSv1.3|
+----------------+----------+------+-------+-------+-------+-------+
| tcd.ie [1] | 20180713 | 18.0 | 35.0 | 0 | 45.0 | 0 |
+----------------+----------+------+-------+-------+-------+-------+
[1] https://www.ietf.org/mail-archive/web/tls/current/msg26633.html
Figure 4: Enterprise Network Statistics
Moriarty & Farrell Expires January 26, 2019 [Page 7]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
5. SHA-1
The integrity of both TLSv1.0 and TLSv1.1 depends on a running SHA-1
hash of the exchanged messages. This makes it possible to perform a
downgrade attack on the handshake by an attacker able to perform 2^77
operations, well below the acceptable modern security margin.
Similarly, the authentication of the handshake depends on signatures
made using SHA-1 hash or a not stronger concatenation of MD-5 and
SHA-1 hashes, allowing the attacker to impersonate a server when it
is able to break the severly weakened SHA-1 hash.
Neither TLSv1.0 nor TLSv1.1 allow the peers to select a stronger hash
for signatures in the ServerKeyExchange or CertificateVerify
messages, making the only upgrade path the use of a newer protocol
version.
See [Bhargavan2016] for additional detail.
6. Do Not Use TLSv1.0
TLSv1.0 MUST NOT be used. Negotiation of TLSv1.0 from any version of
TLS MUST NOT be permitted.
Any other version of TLS is more secure then TLSv1.0. TLSv1.0 can be
configured to prevent interception, though using the highest version
available is preferable.
Pragmatically, clients MUST NOT send a ClientHello with
ClientHello.client_version set to {03,01}. Similarly, servers MUST
NOT send a ServerHello with ServerHello.server_version set to
{03,01}. Any party receiving a Hello message with the protocol
version set to {03,01} MUST respond with a "protocol_version" alert
message and close the connection.
Historically, TLS specifications were not clear on what the record
layer version number (TLSPlaintext.version) could contain when
sending ClientHello. Appendix E of [RFC5246] notes that
TLSPlaintext.version could be selected to maximize interoperability,
though no definitive value is identified as ideal. That guidance is
still applicable; therefore, TLS servers MUST accept any value
{03,XX} (including {03,00}) as the record layer version number for
ClientHello, but they MUST NOT negotiate TLSv1.0.
[[Text here is derived (or stolen:-) from [RFC7568]]]
Moriarty & Farrell Expires January 26, 2019 [Page 8]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
7. Do Not Use TLSv1.1
TLSv1.1 MUST NOT be used. Negotiation of TLSv1.1 from any version of
TLS MUST NOT be permitted.
Pragmatically, clients MUST NOT send a ClientHello with
ClientHello.client_version set to {03,02}. Similarly, servers MUST
NOT send a ServerHello with ServerHello.server_version set to
{03,02}. Any party receiving a Hello message with the protocol
version set to {03,02} MUST respond with a "protocol_version" alert
message and close the connection.
Any newer version of TLS is more secure then TLSv1.1. TLSv1.1 can be
configured to prevent interception, though using the highest version
available is preferable. Support for TLSv1.1 is dwindling in
libraries and will impact security going forward if mitagations for
attacks cannot be easily addressed and supported in older libraries.
Historically, TLS specifications were not clear on what the record
layer version number (TLSPlaintext.version) could contain when
sending ClientHello. Appendix E of [RFC5246] notes that
TLSPlaintext.version could be selected to maximize interoperability,
though no definitive value is identified as ideal. That guidance is
still applicable; therefore, TLS servers MUST accept any value
{03,XX} (including {03,00}) as the record layer version number for
ClientHello, but they MUST NOT negotiate TLSv1.1.
8. Do Not Use SHA-1 in TLSv1.2
[[This section was suggested in PR#2 by Hubert Kario. We're not
clear if the WG would like this draft to include this or not, so will
ask the TLS WG at the appropriate time.]]
SHA-1 as a signature hash MUST NOT be used. That means that clients
MUST send signature_algorithms extension and that extension MUST NOT
include pairs that include SHA-1 hash. In particular, values {2, 1},
{2, 2} and {2, 3} MUST NOT be present in the extension.
Note: this does not affect cipher suites that use SHA-1 HMAC for data
integrity as the HMAC construction is still considered secure and
when they are used in TLSv1.2 SHA-256 is used for handshake
integrity.
9. Updates to RFC7525
[[Since RFC7525 is BCP195, there'll probably be some process-fun to
do an update of that. Formally, it may be that this document becomes
Moriarty & Farrell Expires January 26, 2019 [Page 9]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
a new part of BCP195 I guess, but we can figure that out with chairs
and ADs.]]
This documents updates [RFC7525] Section 3.1.1 changing SHOULD NOT to
MUST NOT as follows:
o Implementations MUST NOT negotiate TLS version 1.0 [RFC2246].
Rationale: TLS 1.0 (published in 1999) does not support many
modern, strong cipher suites. In addition, TLS 1.0 lacks a per-
record Initialization Vector (IV) for CBC-based cipher suites and
does not warn against common padding errors.
o Implementations MUST NOT negotiate TLS version 1.1 [RFC4346].
Rationale: TLS 1.1 (published in 2006) is a security improvement
over TLS 1.0 but still does not support certain stronger cipher
suites.
This documents updates [RFC7525] Section 3.1.2 changing SHOULD NOT to
MUST NOT as follows:
o Implementations MUST NOT negotiate DTLS version 1.0 [RFC4347].
Version 1.0 of DTLS correlates to version 1.1 of TLS (see above).
10. Security Considerations
This document deprecates two older protocol versions for security
reasons already described. The attack surface is reduced when there
are a smaller number of supported protocols and fallback options are
removed.
11. Acknowledgements
Thanks to those that provided usage data, reviewed and/or improved
this document, including: David Benjamin, David Black, Viktor
Dukhovni, Alessandro Ghedini, Jeremy Harris, Russ Housley, Hubert
Kario, Loganaden Velvindron, Eric Mill, Yoav Nir, Andrei Popov, Eric
Rescorla, and Yaron Sheffer.
12. IANA Considerations
[[This memo includes no request to IANA.]]
Moriarty & Farrell Expires January 26, 2019 [Page 10]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
13. References
13.1. 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/info/rfc2119>.
[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",
RFC 2246, DOI 10.17487/RFC2246, January 1999,
<https://www.rfc-editor.org/info/rfc2246>.
[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>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <https://www.rfc-editor.org/info/rfc7525>.
[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/info/rfc8174>.
13.2. Informative References
[Amazon] Amazon, "Amazon Elastic Load Balancing Support Deprecated
TLSv1.0 and TLSv1.1 https://aws.amazon.com/about-aws/
whats-new/2017/02/elastic-load-balancing-support-for-tls-
1-1-and-tls-1-2-pre-defined-security-policies/", 2017.
[Bhargavan2016]
Bhargavan, K. and G. Leuren, "Transcript Collision
Attacks: Breaking Authentication in TLS, IKE, and SSH
https://www.mitls.org/downloads/
transcript-collisions.pdf", 2016.
[Canada] Treasury Board of Canada Secretariat, "Implementing HTTPS
for Secure Web Connections: Information Technology Policy
Implementation Notice (ITPIN)", June 2018,
<https://www.canada.ca/en/treasury-board-
secretariat/services/information-technology/
policy-implementation-notices/
implementing-https-secure-web-connections-itpin.html>.
Moriarty & Farrell Expires January 26, 2019 [Page 11]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
[CloudFlare]
CloudFlare, "CloudFlare Deprecated TLSv1.0 and TLSv1.1
https://blog.cloudflare.com/deprecating-old-tls-versions-
on-cloudflare-dashboard-and-api/", 2018.
[Digicert]
Digicert, "Deprecating TLS 1.0 and 1.1
https://www.digicert.com/blog/
depreciating-tls-1-0-and-1-1/", 2018.
[GIT] GitHub, "GitHub Deprecates TLSv1.0 and TLSv1.1
https://githubengineering.com/crypto-removal-notice/",
2018.
[I-D.ietf-tls-iana-registry-updates]
Salowey, J. and S. Turner, "IANA Registry Updates for
Transport Layer Security (TLS) and Datagram Transport
Layer Security (DTLS)", draft-ietf-tls-iana-registry-
updates-05 (work in progress), May 2018.
[I-D.ietf-tls-tls13]
Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", draft-ietf-tls-tls13-28 (work in progress),
March 2018.
[KeyCDN] KeyCDN, "Deprecating TLS 1.0 and 1.1 Enhancing Security
for Everyone
https://www.keycdn.com/blog/deprecating-tls-1-0-and-1-1/",
2018.
[NIST800-52r2]
National Institute of Standards and Technology, "NIST
SP800-52r2 https://csrc.nist.gov/CSRC/media/Publications/
sp/800-52/rev-2/draft/documents/sp800-52r2-draft.pdf",
2018.
[paypal] Paypal, ""TLS1.2 and HTTP/1.1 Upgrade" https://www.paypal-
notice.com/en/TLS-1.2-and-HTTP1.1-Upgrade/", 2018.
[PCI-TLS1]
PCI Security Standards Council, "Migrating from SSL and
Early TLS https://www.pcisecuritystandards.org/documents/
Migrating-from-SSL-Early-TLS-Info-Supp-v1_1.pdf", 2016.
[RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security", RFC 4347, DOI 10.17487/RFC4347, April 2006,
<https://www.rfc-editor.org/info/rfc4347>.
Moriarty & Farrell Expires January 26, 2019 [Page 12]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 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>.
[RFC7457] Sheffer, Y., Holz, R., and P. Saint-Andre, "Summarizing
Known Attacks on Transport Layer Security (TLS) and
Datagram TLS (DTLS)", RFC 7457, DOI 10.17487/RFC7457,
February 2015, <https://www.rfc-editor.org/info/rfc7457>.
[RFC7568] Barnes, R., Thomson, M., Pironti, A., and A. Langley,
"Deprecating Secure Sockets Layer Version 3.0", RFC 7568,
DOI 10.17487/RFC7568, June 2015,
<https://www.rfc-editor.org/info/rfc7568>.
[SSLpulse]
SSLpulse - will be deleted before publication, "SSLpulse
https://www.ssllabs.com/ssl-pulse/", 2018.
[StackExchange]
StackExchange - will be deleted before publication,
"Stackexchange
https://security.stackexchange.com/questions/177182/is-
there-a-list-of-old-browsers-that-only-support-tls-1-0",
2018.
[stripe] Stripe, ""Upgrading to SHA-2 and TLS 1.2"
https://stripe.com/blog/upgrading-tls", 2018.
Moriarty & Farrell Expires January 26, 2019 [Page 13]
Internet-Draft Deprecating TLSv1.0 and TLSv1.1 July 2018
Appendix A. Change Log
[[RFC editor: please remove this before publication.]]
From -00 to -01:
o Added stats sent to list so far
o PR's #2,3
o a few more references
o added section on email
Authors' Addresses
Kathleen Moriarty
Dell EMC
176 South Street
Hopkinton
United States
EMail: Kathleen.Moriarty.ietf@gmail.com
Stephen Farrell
Trinity College Dublin
Dublin 2
Ireland
Phone: +353-1-896-2354
EMail: stephen.farrell@cs.tcd.ie
Moriarty & Farrell Expires January 26, 2019 [Page 14]
