Deprecating Secure Sockets Layer Version 3.0
RFC 7568
| Document | Type |
RFC - Proposed Standard
(June 2015; Errata)
Updates RFC 5246
|
|
|---|---|---|---|
| Last updated | 2015-12-08 | ||
| Replaces | draft-thomson-sslv3-diediedie | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Joseph Salowey | ||
| Shepherd write-up | Show (last changed 2015-03-01) | ||
| IESG | IESG state | RFC 7568 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Stephen Farrell | ||
| Send notices to | (None) | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | No IC | ||
Internet Engineering Task Force (IETF) R. Barnes
Request for Comments: 7568 M. Thomson
Updates: 5246 Mozilla
Category: Standards Track A. Pironti
ISSN: 2070-1721 INRIA
A. Langley
Google
June 2015
Deprecating Secure Sockets Layer Version 3.0
Abstract
The Secure Sockets Layer version 3.0 (SSLv3), as specified in RFC
6101, is not sufficiently secure. This document requires that SSLv3
not be used. The replacement versions, in particular, Transport
Layer Security (TLS) 1.2 (RFC 5246), are considerably more secure and
capable protocols.
This document updates the backward compatibility section of RFC 5246
and its predecessors to prohibit fallback to SSLv3.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7568.
Barnes, et al. Standards Track [Page 1]
RFC 7568 SSLv3 Is Not Secure June 2015
Copyright Notice
Copyright (c) 2015 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
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
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Do Not Use SSL Version 3.0 . . . . . . . . . . . . . . . . . 3
4. SSLv3 Is Comprehensively Broken . . . . . . . . . . . . . . . 3
4.1. Record Layer . . . . . . . . . . . . . . . . . . . . . . 3
4.2. Key Exchange . . . . . . . . . . . . . . . . . . . . . . 4
4.3. Custom Cryptographic Primitives . . . . . . . . . . . . . 4
5. Limited Capabilities . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Since it was released in 1996, the SSLv3 protocol [RFC6101] has been
subject to a long series of attacks, both on its key exchange
mechanism and on the encryption schemes it supports. Despite being
replaced by TLS 1.0 [RFC2246] in 1999, and subsequently TLS 1.1 in
2002 [RFC4346] and 1.2 in 2006 [RFC5246], availability of these
replacement versions has not been universal. As a result, many
implementations of TLS have permitted the negotiation of SSLv3.
The predecessor of SSLv3, SSL version 2, is no longer considered
sufficiently secure [RFC6176]. SSLv3 now follows.
Barnes, et al. Standards Track [Page 2]
RFC 7568 SSLv3 Is Not Secure June 2015
2. Terminology
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 RFC 2119 [RFC2119].
3. Do Not Use SSL Version 3.0
SSLv3 MUST NOT be used. Negotiation of SSLv3 from any version of TLS
MUST NOT be permitted.
Any version of TLS is more secure than SSLv3, though the highest
version available is preferable.
Pragmatically, clients MUST NOT send a ClientHello with
ClientHello.client_version set to {03,00}. Similarly, servers MUST
NOT send a ServerHello with ServerHello.server_version set to
{03,00}. Any party receiving a Hello message with the protocol
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