Subject: RFC 7627 on Transport Layer Security (TLS) Session Hash and Extended Master Secret Extension

From: [email-masked]
Date: Wed, 16 Sep 2015 13:44:58 -0700 (PDT)

A new Request for Comments is now available in online RFC libraries.

        RFC 7627

        Title:      Transport Layer Security (TLS) Session 
                    Hash and Extended Master Secret Extension 
        Author:     K. Bhargavan, Ed., A. Delignat-Lavaud,
                    A. Pironti, A. Langley, M. Ray
        Status:     Standards Track
        Stream:     IETF
        Date:       September 2015
        Mailbox:    [email-masked], 
                    [email-masked], 
                    [email-masked],
                    [email-masked], 
                    [email-masked]
        Pages:      15
        Characters: 34788
        Updates:    RFC 5246

        I-D Tag:    draft-ietf-tls-session-hash-06.txt

        URL:        https://www.rfc-editor.org/info/rfc7627

        DOI:        http://dx.doi.org/10.17487/RFC7627

The Transport Layer Security (TLS) master secret is not
cryptographically bound to important session parameters such as the
server certificate.  Consequently, it is possible for an active
attacker to set up two sessions, one with a client and another with a
server, such that the master secrets on the two sessions are the
same.  Thereafter, any mechanism that relies on the master secret for
authentication, including session resumption, becomes vulnerable to a
man-in-the-middle attack, where the attacker can simply forward
messages back and forth between the client and server.  This
specification defines a TLS extension that contextually binds the
master secret to a log of the full handshake that computes it, thus
preventing such attacks.

This document is a product of the Transport Layer Security Working Group of the IETF.

This is now a Proposed Standard.

STANDARDS TRACK: This document specifies an Internet Standards Track
protocol for the Internet community, and requests discussion and suggestions
for improvements.  Please refer to the current edition of the Official
Internet Protocol Standards (https://www.rfc-editor.org/standards) for the 
standardization state and status of this protocol.  Distribution of this 
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