source: draft-ietf-httpbis/latest/p7-auth.xml @ 1928

Last change on this file since 1928 was 1924, checked in by julian.reschke@…, 8 years ago

bump up document dates

  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/xml
File size: 48.5 KB
[29]1<?xml version="1.0" encoding="utf-8"?>
[101]2<?xml-stylesheet type='text/xsl' href='../myxml2rfc.xslt'?>
[8]3<!DOCTYPE rfc [
4  <!ENTITY MAY "<bcp14 xmlns=''>MAY</bcp14>">
5  <!ENTITY MUST "<bcp14 xmlns=''>MUST</bcp14>">
6  <!ENTITY MUST-NOT "<bcp14 xmlns=''>MUST NOT</bcp14>">
7  <!ENTITY OPTIONAL "<bcp14 xmlns=''>OPTIONAL</bcp14>">
8  <!ENTITY RECOMMENDED "<bcp14 xmlns=''>RECOMMENDED</bcp14>">
9  <!ENTITY REQUIRED "<bcp14 xmlns=''>REQUIRED</bcp14>">
10  <!ENTITY SHALL "<bcp14 xmlns=''>SHALL</bcp14>">
11  <!ENTITY SHALL-NOT "<bcp14 xmlns=''>SHALL NOT</bcp14>">
12  <!ENTITY SHOULD "<bcp14 xmlns=''>SHOULD</bcp14>">
13  <!ENTITY SHOULD-NOT "<bcp14 xmlns=''>SHOULD NOT</bcp14>">
[29]14  <!ENTITY ID-VERSION "latest">
[1924]15  <!ENTITY ID-MONTH "October">
[1497]16  <!ENTITY ID-YEAR "2012">
[1101]17  <!ENTITY mdash "&#8212;">
[1692]18  <!ENTITY Note "<x:h xmlns:x=''>Note:</x:h>">
[1452]19  <!ENTITY architecture                 "<xref target='Part1' x:rel='#architecture' xmlns:x=''/>">
[1875]20  <!ENTITY conformance                  "<xref target='Part1' x:rel='#conformance' xmlns:x=''/>">
[424]21  <!ENTITY notation                     "<xref target='Part1' x:rel='#notation' xmlns:x=''/>">
[1518]22  <!ENTITY abnf-extension               "<xref target='Part1' x:rel='#abnf.extension' xmlns:x=''/>">
[1399]23  <!ENTITY acks                         "<xref target='Part1' x:rel='#acks' xmlns:x=''/>">
[1518]24  <!ENTITY whitespace                   "<xref target='Part1' x:rel='#whitespace' xmlns:x=''/>">
25  <!ENTITY field-components             "<xref target='Part1' x:rel='#field.components' xmlns:x=''/>">
[961]26  <!ENTITY effective-request-uri        "<xref target='Part1' x:rel='#effective.request.uri' xmlns:x=''/>">
[1518]27  <!ENTITY msg-orient-and-buffering     "<xref target='Part1' x:rel='#intermediaries' xmlns:x=''/>">
[998]28  <!ENTITY end-to-end.and-hop-by-hop    "<xref target='Part1' x:rel='#end-to-end.and.hop-by-hop.header-fields' xmlns:x=''/>">
[1693]29  <!ENTITY status.403                   "<xref target='Part2' x:rel='#status.403' xmlns:x=''/>">
[31]30  <!ENTITY shared-and-non-shared-caches "<xref target='Part6' x:rel='#shared.and.non-shared.caches' xmlns:x=''/>">
32<?rfc toc="yes" ?>
[29]33<?rfc symrefs="yes" ?>
34<?rfc sortrefs="yes" ?>
[8]35<?rfc compact="yes"?>
36<?rfc subcompact="no" ?>
37<?rfc linkmailto="no" ?>
38<?rfc editing="no" ?>
[205]39<?rfc comments="yes"?>
40<?rfc inline="yes"?>
[799]41<?rfc rfcedstyle="yes"?>
[8]42<?rfc-ext allow-markup-in-artwork="yes" ?>
43<?rfc-ext include-references-in-index="yes" ?>
[1477]44<rfc obsoletes="2616" updates="2617" category="std" x:maturity-level="proposed"
[446]45     ipr="pre5378Trust200902" docName="draft-ietf-httpbis-p7-auth-&ID-VERSION;"
[153]46     xmlns:x=''>
[1472]47<x:link rel="prev" basename="p6-cache"/>
[1522]48<x:feedback template="{docname},%20%22{section}%22&amp;body=&lt;{ref}&gt;:"/>
[1864]51  <title abbrev="HTTP/1.1 Authentication">Hypertext Transfer Protocol (HTTP/1.1): Authentication</title>
[29]53  <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
[1106]54    <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
[8]55    <address>
56      <postal>
[1106]57        <street>345 Park Ave</street>
58        <city>San Jose</city>
[8]59        <region>CA</region>
[1106]60        <code>95110</code>
[29]61        <country>USA</country>
[8]62      </postal>
[29]63      <email></email>
64      <uri></uri>
[8]65    </address>
66  </author>
[95]68  <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
69    <organization abbrev="greenbytes">greenbytes GmbH</organization>
70    <address>
71      <postal>
72        <street>Hafenweg 16</street>
73        <city>Muenster</city><region>NW</region><code>48155</code>
74        <country>Germany</country>
75      </postal>
[609]76      <email></email>
77      <uri></uri>
[95]78    </address>
79  </author>
[31]81  <date month="&ID-MONTH;" year="&ID-YEAR;"/>
[440]82  <workgroup>HTTPbis Working Group</workgroup>
[1373]86   The Hypertext Transfer Protocol (HTTP) is an application-level protocol for
[1808]87   distributed, collaborative, hypermedia information systems. This document
88   defines the HTTP Authentication framework.
92<note title="Editorial Note (To be removed by RFC Editor)">
93  <t>
[1764]94    Discussion of this draft takes place on the HTTPBIS working group
[1268]95    mailing list (, which is archived at
96    <eref target=""/>.
97  </t>
98  <t>
99    The current issues list is at
100    <eref target=""/> and related
101    documents (including fancy diffs) can be found at
[324]102    <eref target=""/>.
[36]103  </t>
[153]104  <t>
[1807]105    The changes in this draft are summarized in <xref target="changes.since.20"/>.
[153]106  </t>
110<section title="Introduction" anchor="introduction">
[998]112   This document defines HTTP/1.1 access control and authentication. It
113   includes the relevant parts of <xref target="RFC2616" x:fmt="none">RFC 2616</xref>
[1636]114   with only minor changes (<xref target="RFC2616"/>), plus the general framework for HTTP authentication,
[998]115   as previously defined in "HTTP Authentication: Basic and Digest Access
116   Authentication" (<xref target="RFC2617"/>).
119   HTTP provides several &OPTIONAL; challenge-response authentication
[998]120   mechanisms which can be used by a server to challenge a client request and
121   by a client to provide authentication information. The "basic" and "digest"
122   authentication schemes continue to be specified in
123   <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
[1875]126<section title="Conformance and Error Handling" anchor="conformance">
128   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
129   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
130   document are to be interpreted as described in <xref target="RFC2119"/>.
[1875]133   Conformance criteria and considerations regarding error handling
134   are defined in &conformance;.
[424]138<section title="Syntax Notation" anchor="notation">
[1518]140   This specification uses the Augmented Backus-Naur Form (ABNF) notation
141   of <xref target="RFC5234"/> with the list rule extension defined in
[1805]142   &notation;. <xref target="imported.abnf"/> describes rules imported from
143   other documents. <xref target="collected.abnf"/> shows the collected ABNF
[1518]144   with the list rule expanded.
[998]149<section title="Access Authentication Framework" anchor="access.authentication.framework">
151<section title="Challenge and Response" anchor="challenge.and.response">
[998]152  <x:anchor-alias value="auth-scheme"/>
153  <x:anchor-alias value="auth-param"/>
[1815]154  <x:anchor-alias value="token68"/>
[229]155  <x:anchor-alias value="challenge"/>
156  <x:anchor-alias value="credentials"/>
[998]158   HTTP provides a simple challenge-response authentication mechanism
159   that can be used by a server to challenge a client request and by a
160   client to provide authentication information. It uses an extensible,
[1394]161   case-insensitive token to identify the authentication scheme, followed
162   by additional information necessary for achieving authentication via that
[1473]163   scheme. The latter can either be a comma-separated list of parameters or a
164   single sequence of characters capable of holding base64-encoded
[1394]165   information.
168   Parameters are name-value pairs where the name is matched case-insensitively,
169   and each parameter name &MUST; only occur once per challenge.
[1902]171<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="auth-scheme"/><iref primary="true" item="Grammar" subitem="auth-param"/><iref primary="true" item="Grammar" subitem="token68"/>
[1386]172  auth-scheme    = <x:ref>token</x:ref>
[1386]174  auth-param     = <x:ref>token</x:ref> <x:ref>BWS</x:ref> "=" <x:ref>BWS</x:ref> ( <x:ref>token</x:ref> / <x:ref>quoted-string</x:ref> )
[1815]176  token68        = 1*( <x:ref>ALPHA</x:ref> / <x:ref>DIGIT</x:ref> /
[1394]177                       "-" / "." / "_" / "~" / "+" / "/" ) *"="
[1815]180   The "token68" syntax allows the 66 unreserved URI characters (<xref target="RFC3986"/>),
[1394]181   plus a few others, so that it can hold a base64, base64url (URL and filename
182   safe alphabet), base32, or base16 (hex) encoding, with or without padding, but
183   excluding whitespace (<xref target="RFC4648"/>).
[1708]186   The <x:ref>401 (Unauthorized)</x:ref> response message is used by an origin server
[998]187   to challenge the authorization of a user agent. This response &MUST;
[1736]188   include a <x:ref>WWW-Authenticate</x:ref> header field containing at least one
[1344]189   challenge applicable to the requested resource.
[1736]192   The <x:ref>407 (Proxy Authentication Required)</x:ref> response message is
193   used by a proxy to challenge the authorization of a client and &MUST;
194   include a <x:ref>Proxy-Authenticate</x:ref> header field containing at least
195   one challenge applicable to the proxy for the requested resource.
[1902]197<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="challenge"/>
[1815]198  <x:ref>challenge</x:ref>   = <x:ref>auth-scheme</x:ref> [ 1*<x:ref>SP</x:ref> ( <x:ref>token68</x:ref> / #<x:ref>auth-param</x:ref> ) ]
201  <t>
[1692]202     &Note; User agents will need to take special care in parsing the
[1736]203     <x:ref>WWW-Authenticate</x:ref> and <x:ref>Proxy-Authenticate</x:ref>
204     header field values because they can contain more than one challenge, or
205     if more than one of each is provided, since the contents of a challenge
206     can itself contain a comma-separated list of authentication parameters.
[998]207  </t>
210  <t>
[1692]211     &Note; Many clients fail to parse challenges containing unknown
[1343]212     schemes. A workaround for this problem is to list well-supported schemes
[1344]213     (such as "basic") first.<!-- see -->
[1018]214  </t>
[1344]217   A user agent that wishes to authenticate itself with an origin server
[1708]218   &mdash; usually, but not necessarily, after receiving a <x:ref>401 (Unauthorized)</x:ref>
[1736]219   &mdash; can do so by including an <x:ref>Authorization</x:ref> header field with the
[1344]220   request.
223   A client that wishes to authenticate itself with a proxy &mdash; usually,
[1708]224   but not necessarily, after receiving a <x:ref>407 (Proxy Authentication Required)</x:ref>
[1736]225   &mdash; can do so by including a <x:ref>Proxy-Authorization</x:ref> header field with the
[1344]226   request.
[1736]229   Both the <x:ref>Authorization</x:ref> field value and the <x:ref>Proxy-Authorization</x:ref> field value
[1669]230   contain the client's credentials for the realm of the resource being
231   requested, based upon a challenge received from the server (possibly at
232   some point in the past). When creating their values, the user agent ought to
233   do so by selecting the challenge with what it considers to be the most
234   secure auth-scheme that it understands, obtaining credentials from the user
235   as appropriate.
[1902]237<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="credentials"/>
[1815]238  <x:ref>credentials</x:ref> = <x:ref>auth-scheme</x:ref> [ 1*<x:ref>SP</x:ref> ( <x:ref>token68</x:ref> / #<x:ref>auth-param</x:ref> ) ]
[1694]241   Upon a request for a protected resource that omits credentials, contains
242   invalid credentials (e.g., a bad password) or partial credentials (e.g.,
243   when the authentication scheme requires more than one round trip), an origin
[1736]244   server &SHOULD; return a <x:ref>401 (Unauthorized)</x:ref> response. Such
245   responses &MUST; include a <x:ref>WWW-Authenticate</x:ref> header field
246   containing at least one (possibly new) challenge applicable to the
247   requested resource.
[1694]250   Likewise, upon a request that requires authentication by proxies that omit
251   credentials or contain invalid or partial credentials, a proxy &SHOULD;
[1708]252   return a <x:ref>407 (Proxy Authentication Required)</x:ref> response. Such responses
[1740]253   &MUST; include a <x:ref>Proxy-Authenticate</x:ref> header field containing a (possibly
[1694]254   new) challenge applicable to the proxy.
[1681]257   A server receiving credentials that are valid, but not adequate to gain
[1713]258   access, ought to respond with the <x:ref>403 (Forbidden)</x:ref> status code (&status.403;).
[998]261   The HTTP protocol does not restrict applications to this simple
262   challenge-response mechanism for access authentication. Additional
263   mechanisms &MAY; be used, such as encryption at the transport level or
264   via message encapsulation, and with additional header fields
[1107]265   specifying authentication information. However, such additional
[998]266   mechanisms are not defined by this specification.
[1736]269   Proxies &MUST; forward the <x:ref>WWW-Authenticate</x:ref> and
270   <x:ref>Authorization</x:ref> header fields unmodified and follow the rules
271   found in <xref target="header.authorization"/>.
[1344]275<section title="Protection Space (Realm)" anchor="">
[1354]276  <iref item="Protection Space"/>
277  <iref item="Realm"/>
[1672]278  <iref item="Canonical Root URI"/>
[1354]280   The authentication parameter realm is reserved for use by authentication
[1478]281   schemes that wish to indicate the scope of protection.
[1354]284   A <x:dfn>protection space</x:dfn> is defined by the canonical root URI (the
285   scheme and authority components of the effective request URI; see
286   <xref target="Part1" x:fmt="of" x:rel="#effective.request.uri"/>) of the
287   server being accessed, in combination with the realm value if present.
[1344]288   These realms allow the protected resources on a server to be
289   partitioned into a set of protection spaces, each with its own
290   authentication scheme and/or authorization database. The realm value
291   is a string, generally assigned by the origin server, which can have
292   additional semantics specific to the authentication scheme. Note that
293   there can be multiple challenges with the same auth-scheme but
294   different realms.
297   The protection space determines the domain over which credentials can
298   be automatically applied. If a prior request has been authorized, the
299   same credentials &MAY; be reused for all other requests within that
300   protection space for a period of time determined by the
301   authentication scheme, parameters, and/or user preference. Unless
302   otherwise defined by the authentication scheme, a single protection
303   space cannot extend outside the scope of its server.
306   For historical reasons, senders &MUST; only use the quoted-string syntax.
307   Recipients might have to support both token and quoted-string syntax for
308   maximum interoperability with existing clients that have been accepting both
309   notations for a long time.
[1026]313<section title="Authentication Scheme Registry" anchor="authentication.scheme.registry">
315  The HTTP Authentication Scheme Registry defines the name space for the
316  authentication schemes in challenges and credentials.
319  Registrations &MUST; include the following fields:
320  <list style="symbols">
321    <t>Authentication Scheme Name</t>
322    <t>Pointer to specification text</t>
[1371]323    <t>Notes (optional)</t>
[1026]324  </list>
[1567]327  Values to be added to this name space require IETF Review
328  (see <xref target="RFC5226" x:fmt="," x:sec="4.1"/>).
331  The registry itself is maintained at <eref target=""/>.
334<section title="Considerations for New Authentication Schemes" anchor="">
336  There are certain aspects of the HTTP Authentication Framework that put
337  constraints on how new authentication schemes can work:
340  <list style="symbols">
[1360]341    <x:lt>
[1356]342    <t>
[1518]343      HTTP authentication is presumed to be stateless: all of the information
344      necessary to authenticate a request &MUST; be provided in the request,
345      rather than be dependent on the server remembering prior requests.
346      Authentication based on, or bound to, the underlying connection is
347      outside the scope of this specification and inherently flawed unless
348      steps are taken to ensure that the connection cannot be used by any
349      party other than the authenticated user
350      (see &msg-orient-and-buffering;).
[1356]351    </t>
[1360]352    </x:lt>
353    <x:lt>
[1356]354    <t>
355      The authentication parameter "realm" is reserved for defining Protection
356      Spaces as defined in <xref target=""/>. New schemes
357      &MUST-NOT; use it in a way incompatible with that definition.
358    </t>
[1360]359    </x:lt>
360    <x:lt>
[1356]361    <t>
[1815]362      The "token68" notation was introduced for compatibility with existing
[1394]363      authentication schemes and can only be used once per challenge/credentials.
364      New schemes thus ought to use the "auth-param" syntax instead, because
365      otherwise future extensions will be impossible.
366    </t>
367    </x:lt>
368    <x:lt>
369    <t>
[1465]370      The parsing of challenges and credentials is defined by this specification,
371      and cannot be modified by new authentication schemes. When the auth-param
372      syntax is used, all parameters ought to support both token and
373      quoted-string syntax, and syntactical constraints ought to be defined on
374      the field value after parsing (i.e., quoted-string processing). This is
375      necessary so that recipients can use a generic parser that applies to
376      all authentication schemes.
377    </t>
378    <t>
[1692]379      &Note; The fact that the value syntax for the "realm" parameter
[1465]380      is restricted to quoted-string was a bad design choice not to be repeated
381      for new parameters.
382    </t>
383    </x:lt>
384    <x:lt>
385    <t>
[1562]386      Definitions of new schemes ought to define the treatment of unknown
387      extension parameters. In general, a "must-ignore" rule is preferable
388      over "must-understand", because otherwise it will be hard to introduce
389      new parameters in the presence of legacy recipients. Furthermore,
390      it's good to describe the policy for defining new parameters (such
391      as "update the specification", or "use this registry").
392    </t>
393    </x:lt>
394    <x:lt>
395    <t>
[1357]396      Authentication schemes need to document whether they are usable in
[1736]397      origin-server authentication (i.e., using <x:ref>WWW-Authenticate</x:ref>),
398      and/or proxy authentication (i.e., using <x:ref>Proxy-Authenticate</x:ref>).
[1360]399    </t>
400    </x:lt>
401    <x:lt>
402    <t>
[1736]403      The credentials carried in an <x:ref>Authorization</x:ref> header field are specific to
[1360]404      the User Agent, and therefore have the same effect on HTTP caches as the
405      "private" Cache-Control response directive, within the scope of the
406      request they appear in.
407    </t>
408    <t>
409      Therefore, new authentication schemes which choose not to carry
[1736]410      credentials in the <x:ref>Authorization</x:ref> header field (e.g., using a newly defined
411      header field) will need to explicitly disallow caching, by mandating the use of
[1360]412      either Cache-Control request directives (e.g., "no-store") or response
413      directives (e.g., "private").
414    </t>
415    </x:lt>
[1356]416  </list>
[838]424<section title="Status Code Definitions" anchor="status.code.definitions">
[39]425<section title="401 Unauthorized" anchor="status.401">
426  <iref primary="true" item="401 Unauthorized (status code)" x:for-anchor=""/>
[1708]427  <x:anchor-alias value="401 (Unauthorized)"/>
429   The request requires user authentication. The response &MUST; include a
[1736]430   <x:ref>WWW-Authenticate</x:ref> header field (<xref target="header.www-authenticate"/>)
431   containing a challenge applicable to the target resource. The client &MAY;
432   repeat the request with a suitable <x:ref>Authorization</x:ref> header field
433   (<xref target="header.authorization"/>). If the request already included
434   Authorization credentials, then the 401 response indicates that authorization
435   has been refused for those credentials. If the 401 response contains the
436   same challenge as the prior response, and the user agent has already attempted
[39]437   authentication at least once, then the user &SHOULD; be presented the
[874]438   representation that was given in the response, since that representation might
[998]439   include relevant diagnostic information.
442<section title="407 Proxy Authentication Required" anchor="status.407">
443  <iref primary="true" item="407 Proxy Authentication Required (status code)" x:for-anchor=""/>
[1708]444  <x:anchor-alias value="407 (Proxy Authentication Required)"/>
[1708]446   This code is similar to <x:ref>401 (Unauthorized)</x:ref>, but indicates that the
[998]447   client ought to first authenticate itself with the proxy. The proxy &MUST;
[1736]448   return a <x:ref>Proxy-Authenticate</x:ref> header field (<xref target="header.proxy-authenticate"/>) containing a
[965]449   challenge applicable to the proxy for the target resource. The
[1736]450   client &MAY; repeat the request with a suitable <x:ref>Proxy-Authorization</x:ref>
[998]451   header field (<xref target="header.proxy-authorization"/>).
[1415]456<section title="Header Field Definitions" anchor="header.field.definitions">
[117]458   This section defines the syntax and semantics of HTTP/1.1 header fields
459   related to authentication.
462<section title="Authorization" anchor="header.authorization">
[1120]463  <iref primary="true" item="Authorization header field" x:for-anchor=""/>
[229]464  <x:anchor-alias value="Authorization"/>
[1163]466   The "Authorization" header field allows a user agent to authenticate
[1708]467   itself with a server &mdash; usually, but not necessarily, after receiving a <x:ref>401
468   (Unauthorized)</x:ref> response. Its value consists of credentials containing
[698]469   information of the user agent for the realm of the resource being
470   requested.
[1230]472<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Authorization"/>
473  <x:ref>Authorization</x:ref> = <x:ref>credentials</x:ref>
[998]476   If a request is
[698]477   authenticated and a realm specified, the same credentials &SHOULD;
478   be valid for all other requests within this realm (assuming that
479   the authentication scheme itself does not require otherwise, such
480   as credentials that vary according to a challenge value or using
481   synchronized clocks).
[29]484      When a shared cache (see &shared-and-non-shared-caches;) receives a request
[8]485      containing an Authorization field, it &MUST-NOT; return the
486      corresponding response as a reply to any other request, unless one
487      of the following specific exceptions holds:
490  <list style="numbers">
491      <t>If the response includes the "s-maxage" cache-control
492         directive, the cache &MAY; use that response in replying to a
493         subsequent request. But (if the specified maximum age has
494         passed) a proxy cache &MUST; first revalidate it with the origin
[1163]495         server, using the header fields from the new request to allow
[8]496         the origin server to authenticate the new request. (This is the
497         defined behavior for s-maxage.) If the response includes "s-maxage=0",
498         the proxy &MUST; always revalidate it before re-using
499         it.</t>
501      <t>If the response includes the "must-revalidate" cache-control
502         directive, the cache &MAY; use that response in replying to a
503         subsequent request. But if the response is stale, all caches
504         &MUST; first revalidate it with the origin server, using the
[1163]505         header fields from the new request to allow the origin server
[8]506         to authenticate the new request.</t>
508      <t>If the response includes the "public" cache-control directive,
509         it &MAY; be returned in reply to any subsequent request.</t>
510  </list>
514<section title="Proxy-Authenticate" anchor="header.proxy-authenticate">
[1120]515  <iref primary="true" item="Proxy-Authenticate header field" x:for-anchor=""/>
[229]516  <x:anchor-alias value="Proxy-Authenticate"/>
[1601]518   The "Proxy-Authenticate" header field consists of at least one
519   challenge that indicates the authentication scheme(s) and parameters
520   applicable to the proxy for this effective request URI (&effective-request-uri;).
[1708]521   It &MUST; be included as part of a <x:ref>407 (Proxy Authentication Required)</x:ref> response.
[1230]523<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authenticate"/>
524  <x:ref>Proxy-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
[1736]527   Unlike <x:ref>WWW-Authenticate</x:ref>, the Proxy-Authenticate header field
528   applies only to the current connection, and intermediaries &SHOULD-NOT;
529   forward it to downstream clients. However, an intermediate proxy might need
530   to obtain its own credentials by requesting them from the downstream client,
531   which in some circumstances will appear as if the proxy is forwarding the
[8]532   Proxy-Authenticate header field.
[1736]535   Note that the parsing considerations for <x:ref>WWW-Authenticate</x:ref>
536   apply to this header field as well; see <xref target="header.www-authenticate"/>
537   for details.
541<section title="Proxy-Authorization" anchor="header.proxy-authorization">
[1120]542  <iref primary="true" item="Proxy-Authorization header field" x:for-anchor=""/>
[229]543  <x:anchor-alias value="Proxy-Authorization"/>
[1163]545   The "Proxy-Authorization" header field allows the client to
[8]546   identify itself (or its user) to a proxy which requires
[698]547   authentication. Its value consists of
[8]548   credentials containing the authentication information of the user
549   agent for the proxy and/or realm of the resource being requested.
[1230]551<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authorization"/>
552  <x:ref>Proxy-Authorization</x:ref> = <x:ref>credentials</x:ref>
[1736]555   Unlike <x:ref>Authorization</x:ref>, the Proxy-Authorization header field applies only to
556   the next outbound proxy that demanded authentication using the <x:ref>Proxy-Authenticate</x:ref>
[8]557   field. When multiple proxies are used in a chain, the
558   Proxy-Authorization header field is consumed by the first outbound
559   proxy that was expecting to receive credentials. A proxy &MAY; relay
560   the credentials from the client request to the next proxy if that is
561   the mechanism by which the proxies cooperatively authenticate a given
562   request.
566<section title="WWW-Authenticate" anchor="header.www-authenticate">
[1120]567  <iref primary="true" item="WWW-Authenticate header field" x:for-anchor=""/>
[229]568  <x:anchor-alias value="WWW-Authenticate"/>
[1163]570   The "WWW-Authenticate" header field consists of at least one
[698]571   challenge that indicates the authentication scheme(s) and parameters
[1360]572   applicable to the effective request URI (&effective-request-uri;).
[1708]575   It &MUST; be included in <x:ref>401 (Unauthorized)</x:ref> response messages and &MAY; be
[1360]576   included in other response messages to indicate that supplying credentials
577   (or different credentials) might affect the response.
[1230]579<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="WWW-Authenticate"/>
580  <x:ref>WWW-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
[998]583   User agents are advised to take special care in parsing the WWW-Authenticate
[8]584   field value as it might contain more than one challenge,
585   or if more than one WWW-Authenticate header field is provided, the
586   contents of a challenge itself can contain a comma-separated list of
587   authentication parameters.
590  <preamble>For instance:</preamble>
591  <artwork type="example">
592  WWW-Authenticate: Newauth realm="apps", type=1,
593                    title="Login to \"apps\"", Basic realm="simple"
595  <postamble>
596  This header field contains two challenges; one for the "Newauth" scheme
597  with a realm value of "apps", and two additional parameters "type" and
[1533]598  "title", and another one for the "Basic" scheme with a realm value of
599  "simple".
602  <t>
[1692]603    &Note; The challenge grammar production uses the list syntax as
[1533]604    well. Therefore, a sequence of comma, whitespace, and comma can be
605    considered both as applying to the preceding challenge, or to be an
606    empty entry in the list of challenges. In practice, this ambiguity
607    does not affect the semantics of the header field value and thus is
608    harmless.
609  </t>
[29]615<section title="IANA Considerations" anchor="IANA.considerations">
[1759]617<section title="Authentication Scheme Registry" anchor="authentication.scheme.registration">
619  The registration procedure for HTTP Authentication Schemes is defined by
620  <xref target="authentication.scheme.registry"/> of this document.
623   The HTTP Method Authentication Scheme shall be created at <eref target=""/>.
[700]627<section title="Status Code Registration" anchor="status.code.registration">
629   The HTTP Status Code Registry located at <eref target=""/>
[969]630   shall be updated with the registrations below:
632<?BEGININC p7-auth.iana-status-codes ?>
633<!--AUTOGENERATED FROM extract-status-code-defs.xslt, do not edit manually-->
634<texttable align="left" suppress-title="true" anchor="iana.status.code.registration.table">
635   <ttcol>Value</ttcol>
636   <ttcol>Description</ttcol>
637   <ttcol>Reference</ttcol>
638   <c>401</c>
639   <c>Unauthorized</c>
640   <c>
641      <xref target="status.401"/>
642   </c>
643   <c>407</c>
644   <c>Proxy Authentication Required</c>
645   <c>
646      <xref target="status.407"/>
647   </c>
650<?ENDINC p7-auth.iana-status-codes ?>
[921]653<section title="Header Field Registration" anchor="header.field.registration">
[969]655   The Message Header Field Registry located at <eref target=""/> shall be updated
[290]656   with the permanent registrations below (see <xref target="RFC3864"/>):
[680]658<?BEGININC p7-auth.iana-headers ?>
[253]659<!--AUTOGENERATED FROM extract-header-defs.xslt, do not edit manually-->
[290]660<texttable align="left" suppress-title="true" anchor="iana.header.registration.table">
[253]661   <ttcol>Header Field Name</ttcol>
662   <ttcol>Protocol</ttcol>
663   <ttcol>Status</ttcol>
664   <ttcol>Reference</ttcol>
666   <c>Authorization</c>
667   <c>http</c>
668   <c>standard</c>
669   <c>
670      <xref target="header.authorization"/>
671   </c>
672   <c>Proxy-Authenticate</c>
673   <c>http</c>
674   <c>standard</c>
675   <c>
676      <xref target="header.proxy-authenticate"/>
677   </c>
678   <c>Proxy-Authorization</c>
679   <c>http</c>
680   <c>standard</c>
681   <c>
682      <xref target="header.proxy-authorization"/>
683   </c>
684   <c>WWW-Authenticate</c>
685   <c>http</c>
686   <c>standard</c>
687   <c>
688      <xref target="header.www-authenticate"/>
689   </c>
[680]692<?ENDINC p7-auth.iana-headers ?>
[290]694   The change controller is: "IETF ( - Internet Engineering Task Force".
699<section title="Security Considerations" anchor="security.considerations">
701   This section is meant to inform application developers, information
702   providers, and users of the security limitations in HTTP/1.1 as
703   described by this document. The discussion does not include
704   definitive solutions to the problems revealed, though it does make
705   some suggestions for reducing security risks.
708<section title="Authentication Credentials and Idle Clients" anchor="auth.credentials.and.idle.clients">
710   Existing HTTP clients and user agents typically retain authentication
[145]711   information indefinitely. HTTP/1.1 does not provide a method for a
[8]712   server to direct clients to discard these cached credentials. This is
713   a significant defect that requires further extensions to HTTP.
714   Circumstances under which credential caching can interfere with the
715   application's security model include but are not limited to:
716  <list style="symbols">
717     <t>Clients which have been idle for an extended period following
718        which the server might wish to cause the client to reprompt the
719        user for credentials.</t>
721     <t>Applications which include a session termination indication
[746]722        (such as a "logout" or "commit" button on a page) after which
723        the server side of the application "knows" that there is no
[8]724        further reason for the client to retain the credentials.</t>
725  </list>
728   This is currently under separate study. There are a number of work-arounds
729   to parts of this problem, and we encourage the use of
730   password protection in screen savers, idle time-outs, and other
731   methods which mitigate the security problems inherent in this
732   problem. In particular, user agents which cache credentials are
733   encouraged to provide a readily accessible mechanism for discarding
734   cached credentials under user control.
738<section title="Protection Spaces" anchor="protection.spaces">
740  Authentication schemes that solely rely on the "realm" mechanism for
741  establishing a protection space will expose credentials to all resources on a
742  server. Clients that have successfully made authenticated requests with a
743  resource can use the same authentication credentials for other resources on
744  the same server. This makes it possible for a different resource to harvest
745  authentication credentials for other resources.
748  This is of particular concern when a server hosts resources for multiple
[1791]749  parties under the same canonical root URI (<xref target=""/>).
[1672]750  Possible mitigation strategies include restricting direct access to
751  authentication credentials (i.e., not making the content of the
[1736]752  <x:ref>Authorization</x:ref> request header field available), and separating protection
[1672]753  spaces by using a different host name for each party.
[1364]758<section title="Acknowledgments" anchor="acks">
[998]760  This specification takes over the definition of the HTTP Authentication
[1363]761  Framework, previously defined in <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
762  We thank John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D. Lawrence,
[998]763  Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for their work
[1389]764  on that specification. See <xref target="RFC2617" x:fmt="of" x:sec="6"/>
[1363]765  for further acknowledgements. 
768  See &acks; for the Acknowledgments related to this document revision.
[119]775<references title="Normative References">
[205]777<reference anchor="Part1">
778  <front>
[1864]779    <title>Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing</title>
[205]780    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
[1106]781      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
[205]782      <address><email></email></address>
783    </author>
784    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
785      <organization abbrev="greenbytes">greenbytes GmbH</organization>
786      <address><email></email></address>
787    </author>
788    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
789  </front>
790  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p1-messaging-&ID-VERSION;"/>
791  <x:source href="p1-messaging.xml" basename="p1-messaging"/>
[1693]794<reference anchor="Part2">
795  <front>
[1864]796    <title>Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content</title>
[1693]797    <author fullname="Roy T. Fielding" initials="R." role="editor" surname="Fielding">
798      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
799      <address><email></email></address>
800    </author>
801    <author fullname="Julian F. Reschke" initials="J. F." role="editor" surname="Reschke">
802      <organization abbrev="greenbytes">greenbytes GmbH</organization>
803      <address><email></email></address>
804    </author>
805    <date month="&ID-MONTH;" year="&ID-YEAR;" />
806  </front>
807  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p2-semantics-&ID-VERSION;" />
[1713]808  <x:source basename="p2-semantics" href="p2-semantics.xml">
809    <x:defines>403 (Forbidden)</x:defines>
[1740]810    <x:defines>Location</x:defines>
[1713]811  </x:source>
[31]814<reference anchor="Part6">
[119]815  <front>
[1864]816    <title>Hypertext Transfer Protocol (HTTP/1.1): Caching</title>
[119]817    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
[1106]818      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
[119]819      <address><email></email></address>
820    </author>
[601]821    <author initials="M." surname="Nottingham" fullname="Mark Nottingham" role="editor">
[1915]822      <organization>Akamai</organization>
[601]823      <address><email></email></address>
824    </author>
[119]825    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
826      <organization abbrev="greenbytes">greenbytes GmbH</organization>
827      <address><email></email></address>
828    </author>
829    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
830  </front>
831  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p6-cache-&ID-VERSION;"/>
832  <x:source href="p6-cache.xml" basename="p6-cache"/>
[96]835<reference anchor="RFC2119">
836  <front>
837    <title>Key words for use in RFCs to Indicate Requirement Levels</title>
838    <author initials="S." surname="Bradner" fullname="Scott Bradner">
839      <organization>Harvard University</organization>
840      <address><email></email></address>
841    </author>
842    <date month="March" year="1997"/>
843  </front>
844  <seriesInfo name="BCP" value="14"/>
845  <seriesInfo name="RFC" value="2119"/>
[425]848<reference anchor="RFC5234">
849  <front>
850    <title abbrev="ABNF for Syntax Specifications">Augmented BNF for Syntax Specifications: ABNF</title>
851    <author initials="D." surname="Crocker" fullname="Dave Crocker" role="editor">
852      <organization>Brandenburg InternetWorking</organization>
853      <address>
[728]854        <email></email>
855      </address> 
[425]856    </author>
857    <author initials="P." surname="Overell" fullname="Paul Overell">
858      <organization>THUS plc.</organization>
859      <address>
[728]860        <email></email>
861      </address>
[425]862    </author>
863    <date month="January" year="2008"/>
864  </front>
865  <seriesInfo name="STD" value="68"/>
866  <seriesInfo name="RFC" value="5234"/>
871<references title="Informative References">
873<reference anchor="RFC2616">
874  <front>
875    <title>Hypertext Transfer Protocol -- HTTP/1.1</title>
876    <author initials="R." surname="Fielding" fullname="R. Fielding">
877      <organization>University of California, Irvine</organization>
878      <address><email></email></address>
879    </author>
880    <author initials="J." surname="Gettys" fullname="J. Gettys">
881      <organization>W3C</organization>
882      <address><email></email></address>
883    </author>
884    <author initials="J." surname="Mogul" fullname="J. Mogul">
885      <organization>Compaq Computer Corporation</organization>
886      <address><email></email></address>
887    </author>
888    <author initials="H." surname="Frystyk" fullname="H. Frystyk">
889      <organization>MIT Laboratory for Computer Science</organization>
890      <address><email></email></address>
891    </author>
892    <author initials="L." surname="Masinter" fullname="L. Masinter">
893      <organization>Xerox Corporation</organization>
894      <address><email></email></address>
895    </author>
896    <author initials="P." surname="Leach" fullname="P. Leach">
897      <organization>Microsoft Corporation</organization>
898      <address><email></email></address>
899    </author>
900    <author initials="T." surname="Berners-Lee" fullname="T. Berners-Lee">
901      <organization>W3C</organization>
902      <address><email></email></address>
903    </author>
904    <date month="June" year="1999"/>
905  </front>
906  <seriesInfo name="RFC" value="2616"/>
[998]909<reference anchor="RFC2617">
910  <front>
911    <title abbrev="HTTP Authentication">HTTP Authentication: Basic and Digest Access Authentication</title>
912    <author initials="J." surname="Franks" fullname="John Franks">
913      <organization>Northwestern University, Department of Mathematics</organization>
914      <address><email></email></address>
915    </author>
916    <author initials="P.M." surname="Hallam-Baker" fullname="Phillip M. Hallam-Baker">
917      <organization>Verisign Inc.</organization>
918      <address><email></email></address>
919    </author>
920    <author initials="J.L." surname="Hostetler" fullname="Jeffery L. Hostetler">
921      <organization>AbiSource, Inc.</organization>
922      <address><email></email></address>
923    </author>
924    <author initials="S.D." surname="Lawrence" fullname="Scott D. Lawrence">
925      <organization>Agranat Systems, Inc.</organization>
926      <address><email></email></address>
927    </author>
928    <author initials="P.J." surname="Leach" fullname="Paul J. Leach">
929      <organization>Microsoft Corporation</organization>
930      <address><email></email></address>
931    </author>
932    <author initials="A." surname="Luotonen" fullname="Ari Luotonen">
933      <organization>Netscape Communications Corporation</organization>
934    </author>
935    <author initials="L." surname="Stewart" fullname="Lawrence C. Stewart">
936      <organization>Open Market, Inc.</organization>
937      <address><email></email></address>
938    </author>
939    <date month="June" year="1999"/>
940  </front>
941  <seriesInfo name="RFC" value="2617"/>
[253]944<reference anchor='RFC3864'>
945  <front>
946    <title>Registration Procedures for Message Header Fields</title>
947    <author initials='G.' surname='Klyne' fullname='G. Klyne'>
948      <organization>Nine by Nine</organization>
949      <address><email></email></address>
950    </author>
951    <author initials='M.' surname='Nottingham' fullname='M. Nottingham'>
952      <organization>BEA Systems</organization>
953      <address><email></email></address>
954    </author>
955    <author initials='J.' surname='Mogul' fullname='J. Mogul'>
956      <organization>HP Labs</organization>
957      <address><email></email></address>
958    </author>
959    <date year='2004' month='September' />
960  </front>
961  <seriesInfo name='BCP' value='90' />
962  <seriesInfo name='RFC' value='3864' />
[1394]965<reference anchor="RFC3986">
966 <front>
967  <title abbrev='URI Generic Syntax'>Uniform Resource Identifier (URI): Generic Syntax</title>
968  <author initials='T.' surname='Berners-Lee' fullname='Tim Berners-Lee'>
969    <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
970    <address>
971       <email></email>
972       <uri></uri>
973    </address>
974  </author>
975  <author initials='R.' surname='Fielding' fullname='Roy T. Fielding'>
976    <organization abbrev="Day Software">Day Software</organization>
977    <address>
978      <email></email>
979      <uri></uri>
980    </address>
981  </author>
982  <author initials='L.' surname='Masinter' fullname='Larry Masinter'>
983    <organization abbrev="Adobe Systems">Adobe Systems Incorporated</organization>
984    <address>
985      <email></email>
986      <uri></uri>
987    </address>
988  </author>
989  <date month='January' year='2005'></date>
990 </front>
991 <seriesInfo name="STD" value="66"/>
992 <seriesInfo name="RFC" value="3986"/>
995<reference anchor="RFC4648">
996  <front>
997    <title>The Base16, Base32, and Base64 Data Encodings</title>
998    <author fullname="S. Josefsson" initials="S." surname="Josefsson"/>
999    <date year="2006" month="October"/>
1000  </front>
1001  <seriesInfo value="4648" name="RFC"/>
[1026]1004<reference anchor='RFC5226'>
1005  <front>
1006    <title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
1007    <author initials='T.' surname='Narten' fullname='T. Narten'>
1008      <organization>IBM</organization>
1009      <address><email></email></address>
1010    </author>
1011    <author initials='H.' surname='Alvestrand' fullname='H. Alvestrand'>
1012      <organization>Google</organization>
1013      <address><email></email></address>
1014    </author>
1015    <date year='2008' month='May' />
1016  </front>
1017  <seriesInfo name='BCP' value='26' />
1018  <seriesInfo name='RFC' value='5226' />
[1385]1023<section title="Changes from RFCs 2616 and 2617" anchor="changes.from.rfc.2616">
[1385]1025  The "realm" parameter isn't required anymore in general; consequently, the
1026  ABNF allows challenges without any auth parameters.
1027  (<xref target="access.authentication.framework"/>)
[1815]1030  The "token68" alternative to auth-param lists has been added for consistency
[1394]1031  with legacy authentication schemes such as "Basic".
1032  (<xref target="access.authentication.framework"/>)
[1760]1035  Introduce Authentication Scheme Registry.
1036  (<xref target="authentication.scheme.registry"/>)
[1805]1040<section title="Imported ABNF" anchor="imported.abnf">
1041  <x:anchor-alias value="ALPHA"/>
1042  <x:anchor-alias value="CR"/>
1043  <x:anchor-alias value="DIGIT"/>
1044  <x:anchor-alias value="LF"/>
1045  <x:anchor-alias value="OCTET"/>
1046  <x:anchor-alias value="VCHAR"/>
1047  <x:anchor-alias value="SP"/>
1048  <x:anchor-alias value="quoted-string"/>
1049  <x:anchor-alias value="token"/>
1050  <x:anchor-alias value="BWS"/>
1051  <x:anchor-alias value="OWS"/>
1053  The following core rules are included by
1054  reference, as defined in <xref target="RFC5234" x:fmt="of" x:sec="B.1"/>:
1055  ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls),
1056  DIGIT (decimal 0-9), DQUOTE (double quote),
1057  HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed),
1058  OCTET (any 8-bit sequence of data), SP (space), and
1059  VCHAR (any visible US-ASCII character).
1062   The rules below are defined in <xref target="Part1"/>:
1064<figure><artwork type="abnf2616">
1065  <x:ref>BWS</x:ref>           = &lt;BWS, defined in &whitespace;&gt;
1066  <x:ref>OWS</x:ref>           = &lt;OWS, defined in &whitespace;&gt;
1067  <x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in &field-components;&gt;
1068  <x:ref>token</x:ref>         = &lt;token, defined in &field-components;&gt;
[680]1072<?BEGININC p7-auth.abnf-appendix ?>
[427]1073<section xmlns:x="" title="Collected ABNF" anchor="collected.abnf">
1075<artwork type="abnf" name="p7-auth.parsed-abnf">
[1230]1076<x:ref>Authorization</x:ref> = credentials
[1523]1078<x:ref>BWS</x:ref> = &lt;BWS, defined in [Part1], Section 3.2.1&gt;
[1523]1080<x:ref>OWS</x:ref> = &lt;OWS, defined in [Part1], Section 3.2.1&gt;
[1230]1082<x:ref>Proxy-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS
[425]1083 challenge ] )
[1230]1084<x:ref>Proxy-Authorization</x:ref> = credentials
[1230]1086<x:ref>WWW-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS challenge
1087 ] )
[1386]1089<x:ref>auth-param</x:ref> = token BWS "=" BWS ( token / quoted-string )
[998]1090<x:ref>auth-scheme</x:ref> = token
[1815]1092<x:ref>challenge</x:ref> = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param ) *(
[1394]1093 OWS "," [ OWS auth-param ] ) ] ) ]
[1815]1094<x:ref>credentials</x:ref> = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param )
[1394]1095 *( OWS "," [ OWS auth-param ] ) ] ) ]
[1523]1097<x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in [Part1], Section 3.2.4&gt;
[1523]1099<x:ref>token</x:ref> = &lt;token, defined in [Part1], Section 3.2.4&gt;
[1815]1100<x:ref>token68</x:ref> = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
1101 *"="
[680]1105<?ENDINC p7-auth.abnf-appendix ?>
[252]1107<section title="Change Log (to be removed by RFC Editor before publication)"  anchor="change.log">
[1624]1109  Changes up to the first Working Group Last Call draft are summarized
1110  in <eref target=""/>.
[1592]1113<section title="Since draft-ietf-httpbis-p7-auth-19" anchor="changes.since.19">
[1669]1115  Closed issues:
1116  <list style="symbols">
1117    <t>
[1672]1118      <eref target=""/>:
1119      "Realms and scope"
1120    </t>
1121    <t>
[1669]1122      <eref target=""/>:
1123      "Strength"
1124    </t>
[1681]1125    <t>
1126      <eref target=""/>:
1127      "Authentication exchanges"
1128    </t>
[1682]1129    <t>
1130      <eref target=""/>:
1131      "ABNF requirements for recipients"
1132    </t>
[1760]1133    <t>
1134      <eref target=""/>:
1135      "note introduction of new IANA registries as normative changes"
1136    </t>
[1669]1137  </list>
[1807]1141<section title="Since draft-ietf-httpbis-p7-auth-20" anchor="changes.since.20">
[1815]1143  Closed issues:
1144  <list style="symbols">
1145    <t>
1146      <eref target=""/>:
1147      "rename b64token for clarity"
1148    </t>
1149  </list>
1152  Other changes:
1153  <list style="symbols">
1154    <t>
1155      Conformance criteria and considerations regarding error handling are
1156      now defined in Part 1.
1157    </t>
1158  </list>
Note: See TracBrowser for help on using the repository browser.