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
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Stream WG state Submitted to IESG for Publication
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IESG IESG state RFC 7568 (Proposed Standard)
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Responsible AD Stephen Farrell
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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.
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