First-Party Cookies
draft-west-first-party-cookies-00

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Document Type Active Internet-Draft (individual)
Last updated 2014-10-27
Replaced by draft-ietf-httpbis-cookie-same-site
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HTTPbis                                                          M. West
Internet-Draft                                               Google, Inc
Updates: 6265 (if approved)                             October 27, 2014
Intended status: Standards Track
Expires: April 30, 2015

                          First-Party Cookies
                   draft-west-first-party-cookies-00

Abstract

   This document updates RFC6265, defining the "First-Party" attribute
   for cookies, which allows servers to mitigate the risk of cross-site
   request forgery and related information leakage attacks by asserting
   that a particular cookie should only be sent in a "first-party"
   context.

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
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   This Internet-Draft will expire on April 30, 2015.

Copyright Notice

   Copyright (c) 2014 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

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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Examples  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology and notation  . . . . . . . . . . . . . . . . . .   3
     2.1.  First-party and Third-party Requests  . . . . . . . . . .   3
   3.  Server Requirements . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  Grammar . . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Semantics of the "First-Party" Attribute (Non-Normative)    4
   4.  User Agent Requirements . . . . . . . . . . . . . . . . . . .   5
     4.1.  The "First-Party" attribute . . . . . . . . . . . . . . .   5
     4.2.  Monkey-patching the Storage Model . . . . . . . . . . . .   5
     4.3.  Monkey-patching the "Cookie" header . . . . . . . . . . .   6
   5.  Authoring Considerations  . . . . . . . . . . . . . . . . . .   6
     5.1.  Mashups and Widgets . . . . . . . . . . . . . . . . . . .   6
   6.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .   6
     6.1.  User Controls . . . . . . . . . . . . . . . . . . . . . .   6
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
     7.1.  Limitations . . . . . . . . . . . . . . . . . . . . . . .   7
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   Section 8.2 of [RFC6265] eloquently notes that cookies are a form of
   ambient authority, attached by default to requests the user agent
   sends on a user's behalf.  Even when an attacker doesn't know the
   contents of a user's cookies, she can still execute commands on the
   user's behalf (and with the user's authority) by asking the user
   agent to send HTTP requests to unwary servers.

   Here, we update [RFC6265] with a simple mitigation strategy that
   allows servers to declare certain cookies as "First-party cookies"
   which should be attached to requests if and only if they occur in a
   first-party context.

   Note that the mechanism outlined here is backwards compatible with
   the existing cookie syntax.  Servers may serve first-party cookies to
   all user agents; those that do not support the "First-Party"
   attribute will simply store a non-first-party cookie, just as they do
   today.

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1.1.  Examples

   First-party cookies are set via the "First-Party" attribute in the
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