HTTP State Management Mechanism
RFC 6265

Internet Engineering Task Force (IETF)                          A. Barth
Request for Comments: 6265                                 U.C. Berkeley
Obsoletes: 2965                                               April 2011
Category: Standards Track
ISSN: 2070-1721

                    HTTP State Management Mechanism

Abstract

   This document defines the HTTP Cookie and Set-Cookie header fields.
   These header fields can be used by HTTP servers to store state
   (called cookies) at HTTP user agents, letting the servers maintain a
   stateful session over the mostly stateless HTTP protocol.  Although
   cookies have many historical infelicities that degrade their security
   and privacy, the Cookie and Set-Cookie header fields are widely used
   on the Internet.  This document obsoletes RFC 2965.

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/rfc6265.

Copyright Notice

   Copyright (c) 2011 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
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   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.

Barth                        Standards Track                    [Page 1]
RFC 6265             HTTP State Management Mechanism          April 2011

   This document may contain material from IETF Documents or IETF
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   Without obtaining an adequate license from the person(s) controlling
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   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1. Introduction ....................................................3
   2. Conventions .....................................................4
      2.1. Conformance Criteria .......................................4
      2.2. Syntax Notation ............................................5
      2.3. Terminology ................................................5
   3. Overview ........................................................6
      3.1. Examples ...................................................6
   4. Server Requirements .............................................8
      4.1. Set-Cookie .................................................8
           4.1.1. Syntax ..............................................8
           4.1.2. Semantics (Non-Normative) ..........................10
      4.2. Cookie ....................................................13
           4.2.1. Syntax .............................................13
           4.2.2. Semantics ..........................................13
   5. User Agent Requirements ........................................14
      5.1. Subcomponent Algorithms ...................................14
           5.1.1. Dates ..............................................14
           5.1.2. Canonicalized Host Names ...........................16
           5.1.3. Domain Matching ....................................16
           5.1.4. Paths and Path-Match ...............................16
      5.2. The Set-Cookie Header .....................................17
           5.2.1. The Expires Attribute ..............................19
           5.2.2. The Max-Age Attribute ..............................20
           5.2.3. The Domain Attribute ...............................20
           5.2.4. The Path Attribute .................................21
           5.2.5. The Secure Attribute ...............................21