source: draft-ietf-httpbis/latest/p7-auth.html @ 454

Last change on this file since 454 was 454, checked in by julian.reschke@…, 14 years ago

fix line wrap in ABNF prose problem; update XSLT for collected ABNF to move diagnostics into separate figure
  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/html;charset=utf-8
File size: 66.0 KB
Line 
1<!DOCTYPE html
2  PUBLIC "-//W3C//DTD HTML 4.01//EN">
3<html lang="en">
4   <head profile="http://www.w3.org/2006/03/hcard">
5      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
6      <title>HTTP/1.1, part 7: Authentication</title><style type="text/css" title="Xml2Rfc (sans serif)">
7a {
8  text-decoration: none;
9}
10a.smpl {
11  color: black;
12}
13a:hover {
14  text-decoration: underline;
15}
16a:active {
17  text-decoration: underline;
18}
19address {
20  margin-top: 1em;
21  margin-left: 2em;
22  font-style: normal;
23}
24body {
25  color: black;
26  font-family: verdana, helvetica, arial, sans-serif;
27  font-size: 10pt;
28}
29cite {
30  font-style: normal;
31}
32dd {
33  margin-right: 2em;
34}
35dl {
36  margin-left: 2em;
37}
38
39dl.empty dd {
40  margin-top: .5em;
41}
42dl p {
43  margin-left: 0em;
44}
45dt {
46  margin-top: .5em;
47}
48h1 {
49  font-size: 14pt;
50  line-height: 21pt;
51  page-break-after: avoid;
52}
53h1.np {
54  page-break-before: always;
55}
56h1 a {
57  color: #333333;
58}
59h2 {
60  font-size: 12pt;
61  line-height: 15pt;
62  page-break-after: avoid;
63}
64h3, h4, h5, h6 {
65  font-size: 10pt;
66  page-break-after: avoid;
67}
68h2 a, h3 a, h4 a, h5 a, h6 a {
69  color: black;
70}
71img {
72  margin-left: 3em;
73}
74li {
75  margin-left: 2em;
76  margin-right: 2em;
77}
78ol {
79  margin-left: 2em;
80  margin-right: 2em;
81}
82ol p {
83  margin-left: 0em;
84}
85p {
86  margin-left: 2em;
87  margin-right: 2em;
88}
89pre {
90  margin-left: 3em;
91  background-color: lightyellow;
92  padding: .25em;
93}
94pre.text2 {
95  border-style: dotted;
96  border-width: 1px;
97  background-color: #f0f0f0;
98  width: 69em;
99}
100pre.inline {
101  background-color: white;
102  padding: 0em;
103}
104pre.text {
105  border-style: dotted;
106  border-width: 1px;
107  background-color: #f8f8f8;
108  width: 69em;
109}
110pre.drawing {
111  border-style: solid;
112  border-width: 1px;
113  background-color: #f8f8f8;
114  padding: 2em;
115}
116table {
117  margin-left: 2em;
118}
119table.tt {
120  vertical-align: top;
121}
122table.full {
123  border-style: outset;
124  border-width: 1px;
125}
126table.headers {
127  border-style: outset;
128  border-width: 1px;
129}
130table.tt td {
131  vertical-align: top;
132}
133table.full td {
134  border-style: inset;
135  border-width: 1px;
136}
137table.tt th {
138  vertical-align: top;
139}
140table.full th {
141  border-style: inset;
142  border-width: 1px;
143}
144table.headers th {
145  border-style: none none inset none;
146  border-width: 1px;
147}
148caption {
149  caption-side: bottom;
150  font-weight: bold;
151  font-size: 9pt;
152  margin-top: .5em;
153}
154
155table.header {
156  width: 95%;
157  font-size: 10pt;
158  color: white;
159}
160td.top {
161  vertical-align: top;
162}
163td.topnowrap {
164  vertical-align: top;
165  white-space: nowrap;
166}
167td.header {
168  background-color: gray;
169  width: 50%;
170}
171td.header a {
172  color: white;
173}
174td.reference {
175  vertical-align: top;
176  white-space: nowrap;
177  padding-right: 1em;
178}
179thead {
180  display:table-header-group;
181}
182ul.toc {
183  list-style: none;
184  margin-left: 1.5em;
185  margin-right: 0em;
186  padding-left: 0em;
187}
188li.tocline0 {
189  line-height: 150%;
190  font-weight: bold;
191  font-size: 10pt;
192  margin-left: 0em;
193  margin-right: 0em;
194}
195li.tocline1 {
196  line-height: normal;
197  font-weight: normal;
198  font-size: 9pt;
199  margin-left: 0em;
200  margin-right: 0em;
201}
202li.tocline2 {
203  font-size: 0pt;
204}
205ul p {
206  margin-left: 0em;
207}
208ul.ind {
209  list-style: none;
210  margin-left: 1.5em;
211  margin-right: 0em;
212  padding-left: 0em;
213  page-break-before: avoid;
214}
215li.indline0 {
216  font-weight: bold;
217  line-height: 200%;
218  margin-left: 0em;
219  margin-right: 0em;
220}
221li.indline1 {
222  font-weight: normal;
223  line-height: 150%;
224  margin-left: 0em;
225  margin-right: 0em;
226}
227.bcp14 {
228  font-style: normal;
229  text-transform: lowercase;
230  font-variant: small-caps;
231}
232.comment {
233  background-color: yellow;
234}
235.center {
236  text-align: center;
237}
238.error {
239  color: red;
240  font-style: italic;
241  font-weight: bold;
242}
243.figure {
244  font-weight: bold;
245  text-align: center;
246  font-size: 9pt;
247}
248.filename {
249  color: #333333;
250  font-weight: bold;
251  font-size: 12pt;
252  line-height: 21pt;
253  text-align: center;
254}
255.fn {
256  font-weight: bold;
257}
258.hidden {
259  display: none;
260}
261.left {
262  text-align: left;
263}
264.right {
265  text-align: right;
266}
267.title {
268  color: #990000;
269  font-size: 18pt;
270  line-height: 18pt;
271  font-weight: bold;
272  text-align: center;
273  margin-top: 36pt;
274}
275.vcardline {
276  display: block;
277}
278.warning {
279  font-size: 14pt;
280  background-color: yellow;
281}
282
283
284@media print {
285  .noprint {
286    display: none;
287  }
288 
289  a {
290    color: black;
291    text-decoration: none;
292  }
293
294  table.header {
295    width: 90%;
296  }
297
298  td.header {
299    width: 50%;
300    color: black;
301    background-color: white;
302    vertical-align: top;
303    font-size: 12pt;
304  }
305
306  ul.toc a::after {
307    content: leader('.') target-counter(attr(href), page);
308  }
309 
310  a.iref {
311    content: target-counter(attr(href), page);
312  }
313 
314  .print2col {
315    column-count: 2;
316    -moz-column-count: 2;
317    column-fill: auto;
318  }
319}
320
321@page {
322  @top-left {
323       content: "INTERNET DRAFT";
324  }
325  @top-right {
326       content: "February 2009";
327  }
328  @top-center {
329       content: "HTTP/1.1, Part 7";
330  }
331  @bottom-left {
332       content: "Fielding, et al.";
333  }
334  @bottom-center {
335       content: "Standards Track";
336  }
337  @bottom-right {
338       content: "[Page " counter(page) "]";
339  }
340}
341
342@page:first {
343    @top-left {
344      content: normal;
345    }
346    @top-right {
347      content: normal;
348    }
349    @top-center {
350      content: normal;
351    }
352}
353</style><link rel="Contents" href="#rfc.toc">
354      <link rel="Author" href="#rfc.authors">
355      <link rel="Copyright" href="#rfc.copyright">
356      <link rel="Index" href="#rfc.index">
357      <link rel="Chapter" title="1 Introduction" href="#rfc.section.1">
358      <link rel="Chapter" title="2 Status Code Definitions" href="#rfc.section.2">
359      <link rel="Chapter" title="3 Header Field Definitions" href="#rfc.section.3">
360      <link rel="Chapter" title="4 IANA Considerations" href="#rfc.section.4">
361      <link rel="Chapter" title="5 Security Considerations" href="#rfc.section.5">
362      <link rel="Chapter" title="6 Acknowledgments" href="#rfc.section.6">
363      <link rel="Chapter" href="#rfc.section.7" title="7 References">
364      <link rel="Appendix" title="A Compatibility with Previous Versions" href="#rfc.section.A">
365      <link rel="Appendix" title="B Collected ABNF" href="#rfc.section.B">
366      <link rel="Appendix" title="C Change Log (to be removed by RFC Editor before publication)" href="#rfc.section.C">
367      <meta name="generator" content="http://greenbytes.de/tech/webdav/rfc2629.xslt, Revision 1.424, 2009-02-24 16:15:29, XSLT vendor: SAXON 8.9 from Saxonica http://www.saxonica.com/">
368      <link rel="schema.DC" href="http://purl.org/dc/elements/1.1/">
369      <meta name="DC.Creator" content="Fielding, R.">
370      <meta name="DC.Creator" content="Gettys, J.">
371      <meta name="DC.Creator" content="Mogul, J.">
372      <meta name="DC.Creator" content="Frystyk, H.">
373      <meta name="DC.Creator" content="Masinter, L.">
374      <meta name="DC.Creator" content="Leach, P.">
375      <meta name="DC.Creator" content="Berners-Lee, T.">
376      <meta name="DC.Creator" content="Lafon, Y.">
377      <meta name="DC.Creator" content="Reschke, J. F.">
378      <meta name="DC.Identifier" content="urn:ietf:id:draft-ietf-httpbis-p7-auth-latest">
379      <meta name="DC.Date.Issued" scheme="ISO8601" content="2009-02">
380      <meta name="DC.Relation.Replaces" content="urn:ietf:rfc:2616">
381      <meta name="DC.Description.Abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 7 of the seven-part specification that defines the protocol referred to as &#34;HTTP/1.1&#34; and, taken together, obsoletes RFC 2616. Part 7 defines HTTP Authentication.">
382   </head>
383   <body>
384      <table summary="header information" class="header" border="0" cellpadding="1" cellspacing="1">
385         <tr>
386            <td class="header left">HTTPbis Working Group</td>
387            <td class="header right">R. Fielding, Editor</td>
388         </tr>
389         <tr>
390            <td class="header left">Internet Draft</td>
391            <td class="header right">Day Software</td>
392         </tr>
393         <tr>
394            <td class="header left">
395               &lt;draft-ietf-httpbis-p7-auth-latest&gt;
396               
397            </td>
398            <td class="header right">J. Gettys</td>
399         </tr>
400         <tr>
401            <td class="header left">Obsoletes: <a href="http://tools.ietf.org/html/rfc2616">2616</a> (if approved)
402            </td>
403            <td class="header right">One Laptop per Child</td>
404         </tr>
405         <tr>
406            <td class="header left">Updates: <a href="http://tools.ietf.org/html/rfc2617">2617</a> (if approved)
407            </td>
408            <td class="header right">J. Mogul</td>
409         </tr>
410         <tr>
411            <td class="header left">Intended status: Standards Track</td>
412            <td class="header right">HP</td>
413         </tr>
414         <tr>
415            <td class="header left">Expires: August 2009</td>
416            <td class="header right">H. Frystyk</td>
417         </tr>
418         <tr>
419            <td class="header left"></td>
420            <td class="header right">Microsoft</td>
421         </tr>
422         <tr>
423            <td class="header left"></td>
424            <td class="header right">L. Masinter</td>
425         </tr>
426         <tr>
427            <td class="header left"></td>
428            <td class="header right">Adobe Systems</td>
429         </tr>
430         <tr>
431            <td class="header left"></td>
432            <td class="header right">P. Leach</td>
433         </tr>
434         <tr>
435            <td class="header left"></td>
436            <td class="header right">Microsoft</td>
437         </tr>
438         <tr>
439            <td class="header left"></td>
440            <td class="header right">T. Berners-Lee</td>
441         </tr>
442         <tr>
443            <td class="header left"></td>
444            <td class="header right">W3C/MIT</td>
445         </tr>
446         <tr>
447            <td class="header left"></td>
448            <td class="header right">Y. Lafon, Editor</td>
449         </tr>
450         <tr>
451            <td class="header left"></td>
452            <td class="header right">W3C</td>
453         </tr>
454         <tr>
455            <td class="header left"></td>
456            <td class="header right">J. F. Reschke, Editor</td>
457         </tr>
458         <tr>
459            <td class="header left"></td>
460            <td class="header right">greenbytes</td>
461         </tr>
462         <tr>
463            <td class="header left"></td>
464            <td class="header right">February 28, 2009</td>
465         </tr>
466      </table>
467      <p class="title">HTTP/1.1, part 7: Authentication<br><span class="filename">draft-ietf-httpbis-p7-auth-latest</span></p>
468      <h1><a id="rfc.status" href="#rfc.status">Status of this Memo</a></h1>
469      <p>This Internet-Draft is submitted to IETF pursuant to, and in full conformance with, the provisions of BCP 78 and BCP 79. This
470         document may contain material from IETF Documents or IETF Contributions published or made publicly available before November
471         10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to
472         allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s)
473         controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative
474         works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate
475         it into languages other than English.
476      </p>
477      <p>Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note
478         that other groups may also distribute working documents as Internet-Drafts.
479      </p>
480      <p>Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other
481         documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as “work
482         in progress”.
483      </p>
484      <p>The list of current Internet-Drafts can be accessed at &lt;<a href="http://www.ietf.org/ietf/1id-abstracts.txt">http://www.ietf.org/ietf/1id-abstracts.txt</a>&gt;.
485      </p>
486      <p>The list of Internet-Draft Shadow Directories can be accessed at &lt;<a href="http://www.ietf.org/shadow.html">http://www.ietf.org/shadow.html</a>&gt;.
487      </p>
488      <p>This Internet-Draft will expire in August 2009.</p>
489      <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1>
490      <p>Copyright © 2009 IETF Trust and the persons identified as the document authors. All rights reserved.</p>
491      <p>This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date
492         of publication of this document (<a href="http://trustee.ietf.org/license-info">http://trustee.ietf.org/license-info</a>). Please review these documents carefully, as they describe your rights and restrictions with respect to this document.
493      </p>
494      <h1 id="rfc.abstract"><a href="#rfc.abstract">Abstract</a></h1>
495      <p>The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information
496         systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 7 of the
497         seven-part specification that defines the protocol referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part
498         7 defines HTTP Authentication.
499      </p>
500      <h1 id="rfc.note.1"><a href="#rfc.note.1">Editorial Note (To be removed by RFC Editor)</a></h1>
501      <p>Discussion of this draft should take place on the HTTPBIS working group mailing list (ietf-http-wg@w3.org). The current issues
502         list is at &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/report/11">http://tools.ietf.org/wg/httpbis/trac/report/11</a>&gt; and related documents (including fancy diffs) can be found at &lt;<a href="http://tools.ietf.org/wg/httpbis/">http://tools.ietf.org/wg/httpbis/</a>&gt;.
503      </p> 
504      <p>The changes in this draft are summarized in <a href="#changes.since.05" title="Since draft-ietf-httpbis-p7-auth-05">Appendix&nbsp;C.7</a>.
505      </p>
506      <hr class="noprint">
507      <h1 class="np" id="rfc.toc"><a href="#rfc.toc">Table of Contents</a></h1>
508      <ul class="toc">
509         <li class="tocline0">1.&nbsp;&nbsp;&nbsp;<a href="#introduction">Introduction</a><ul class="toc">
510               <li class="tocline1">1.1&nbsp;&nbsp;&nbsp;<a href="#intro.requirements">Requirements</a></li>
511               <li class="tocline1">1.2&nbsp;&nbsp;&nbsp;<a href="#notation">Syntax Notation</a><ul class="toc">
512                     <li class="tocline1">1.2.1&nbsp;&nbsp;&nbsp;<a href="#core.rules">Core Rules</a></li>
513                     <li class="tocline1">1.2.2&nbsp;&nbsp;&nbsp;<a href="#abnf.dependencies">ABNF Rules defined in other Parts of the Specification</a></li>
514                  </ul>
515               </li>
516            </ul>
517         </li>
518         <li class="tocline0">2.&nbsp;&nbsp;&nbsp;<a href="#rfc.section.2">Status Code Definitions</a><ul class="toc">
519               <li class="tocline1">2.1&nbsp;&nbsp;&nbsp;<a href="#status.401">401 Unauthorized</a></li>
520               <li class="tocline1">2.2&nbsp;&nbsp;&nbsp;<a href="#status.407">407 Proxy Authentication Required</a></li>
521            </ul>
522         </li>
523         <li class="tocline0">3.&nbsp;&nbsp;&nbsp;<a href="#header.fields">Header Field Definitions</a><ul class="toc">
524               <li class="tocline1">3.1&nbsp;&nbsp;&nbsp;<a href="#header.authorization">Authorization</a></li>
525               <li class="tocline1">3.2&nbsp;&nbsp;&nbsp;<a href="#header.proxy-authenticate">Proxy-Authenticate</a></li>
526               <li class="tocline1">3.3&nbsp;&nbsp;&nbsp;<a href="#header.proxy-authorization">Proxy-Authorization</a></li>
527               <li class="tocline1">3.4&nbsp;&nbsp;&nbsp;<a href="#header.www-authenticate">WWW-Authenticate</a></li>
528            </ul>
529         </li>
530         <li class="tocline0">4.&nbsp;&nbsp;&nbsp;<a href="#IANA.considerations">IANA Considerations</a><ul class="toc">
531               <li class="tocline1">4.1&nbsp;&nbsp;&nbsp;<a href="#message.header.registration">Message Header Registration</a></li>
532            </ul>
533         </li>
534         <li class="tocline0">5.&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul class="toc">
535               <li class="tocline1">5.1&nbsp;&nbsp;&nbsp;<a href="#auth.credentials.and.idle.clients">Authentication Credentials and Idle Clients</a></li>
536            </ul>
537         </li>
538         <li class="tocline0">6.&nbsp;&nbsp;&nbsp;<a href="#ack">Acknowledgments</a></li>
539         <li class="tocline0">7.&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul class="toc">
540               <li class="tocline1">7.1&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li>
541               <li class="tocline1">7.2&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li>
542            </ul>
543         </li>
544         <li class="tocline0"><a href="#rfc.authors">Authors' Addresses</a></li>
545         <li class="tocline0">A.&nbsp;&nbsp;&nbsp;<a href="#compatibility">Compatibility with Previous Versions</a><ul class="toc">
546               <li class="tocline1">A.1&nbsp;&nbsp;&nbsp;<a href="#changes.from.rfc.2616">Changes from RFC 2616</a></li>
547            </ul>
548         </li>
549         <li class="tocline0">B.&nbsp;&nbsp;&nbsp;<a href="#collected.abnf">Collected ABNF</a></li>
550         <li class="tocline0">C.&nbsp;&nbsp;&nbsp;<a href="#change.log">Change Log (to be removed by RFC Editor before publication)</a><ul class="toc">
551               <li class="tocline1">C.1&nbsp;&nbsp;&nbsp;<a href="#rfc.section.C.1">Since RFC2616</a></li>
552               <li class="tocline1">C.2&nbsp;&nbsp;&nbsp;<a href="#rfc.section.C.2">Since draft-ietf-httpbis-p7-auth-00</a></li>
553               <li class="tocline1">C.3&nbsp;&nbsp;&nbsp;<a href="#rfc.section.C.3">Since draft-ietf-httpbis-p7-auth-01</a></li>
554               <li class="tocline1">C.4&nbsp;&nbsp;&nbsp;<a href="#changes.since.02">Since draft-ietf-httpbis-p7-auth-02</a></li>
555               <li class="tocline1">C.5&nbsp;&nbsp;&nbsp;<a href="#changes.since.03">Since draft-ietf-httpbis-p7-auth-03</a></li>
556               <li class="tocline1">C.6&nbsp;&nbsp;&nbsp;<a href="#changes.since.04">Since draft-ietf-httpbis-p7-auth-04</a></li>
557               <li class="tocline1">C.7&nbsp;&nbsp;&nbsp;<a href="#changes.since.05">Since draft-ietf-httpbis-p7-auth-05</a></li>
558            </ul>
559         </li>
560         <li class="tocline0"><a href="#rfc.index">Index</a></li>
561      </ul>
562      <h1 id="rfc.section.1" class="np"><a href="#rfc.section.1">1.</a>&nbsp;<a id="introduction" href="#introduction">Introduction</a></h1>
563      <p id="rfc.section.1.p.1">This document defines HTTP/1.1 access control and authentication. Right now it includes the extracted relevant sections of <cite title="Hypertext Transfer Protocol -- HTTP/1.1" id="rfc.xref.RFC2616.1">RFC 2616</cite> with only minor changes. The intention is to move the general framework for HTTP authentication here, as currently specified
564         in <a href="#RFC2617" id="rfc.xref.RFC2617.1"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>, and allow the individual authentication mechanisms to be defined elsewhere. This introduction will be rewritten when that
565         occurs.
566      </p>
567      <p id="rfc.section.1.p.2">HTTP provides several <em class="bcp14">OPTIONAL</em> challenge-response authentication mechanisms which can be used by a server to challenge a client request and by a client to
568         provide authentication information. The general framework for access authentication, and the specification of "basic" and
569         "digest" authentication, are specified in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.2"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. This specification adopts the definitions of "challenge" and "credentials" from that specification.
570      </p>
571      <h2 id="rfc.section.1.1"><a href="#rfc.section.1.1">1.1</a>&nbsp;<a id="intro.requirements" href="#intro.requirements">Requirements</a></h2>
572      <p id="rfc.section.1.1.p.1">The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
573         in this document are to be interpreted as described in <a href="#RFC2119" id="rfc.xref.RFC2119.1"><cite title="Key words for use in RFCs to Indicate Requirement Levels">[RFC2119]</cite></a>.
574      </p>
575      <p id="rfc.section.1.1.p.2">An implementation is not compliant if it fails to satisfy one or more of the <em class="bcp14">MUST</em> or <em class="bcp14">REQUIRED</em> level requirements for the protocols it implements. An implementation that satisfies all the <em class="bcp14">MUST</em> or <em class="bcp14">REQUIRED</em> level and all the <em class="bcp14">SHOULD</em> level requirements for its protocols is said to be "unconditionally compliant"; one that satisfies all the <em class="bcp14">MUST</em> level requirements but not all the <em class="bcp14">SHOULD</em> level requirements for its protocols is said to be "conditionally compliant."
576      </p>
577      <h2 id="rfc.section.1.2"><a href="#rfc.section.1.2">1.2</a>&nbsp;<a id="notation" href="#notation">Syntax Notation</a></h2>
578      <p id="rfc.section.1.2.p.1">This specification uses the ABNF syntax defined in <a href="p1-messaging.html#notation" title="Syntax Notation">Section 1.2</a> of <a href="#Part1" id="rfc.xref.Part1.1"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. The following core rules are included by reference, as defined in <a href="#RFC5234" id="rfc.xref.RFC5234.1"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>, <a href="http://tools.ietf.org/html/rfc5234#appendix-B.1">Appendix B.1</a>: ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double quote), HEXDIG
579         (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any 8-bit sequence of data), SP (space), VCHAR (any visible USASCII character),
580         and WSP (whitespace).
581      </p>
582      <h3 id="rfc.section.1.2.1"><a href="#rfc.section.1.2.1">1.2.1</a>&nbsp;<a id="core.rules" href="#core.rules">Core Rules</a></h3>
583      <p id="rfc.section.1.2.1.p.1">The core rules below are defined in <a href="p1-messaging.html#basic.rules" title="Basic Rules">Section 1.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.2"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>:
584      </p>
585      <div id="rfc.figure.u.1"></div><pre class="inline">  <a href="#core.rules" class="smpl">OWS</a>         = &lt;OWS, defined in <a href="#Part1" id="rfc.xref.Part1.3"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#basic.rules" title="Basic Rules">Section 1.2.2</a>&gt;
586</pre><h3 id="rfc.section.1.2.2"><a href="#rfc.section.1.2.2">1.2.2</a>&nbsp;<a id="abnf.dependencies" href="#abnf.dependencies">ABNF Rules defined in other Parts of the Specification</a></h3>
587      <p id="rfc.section.1.2.2.p.1">  The ABNF rules below are defined in other specifications:</p>
588      <div id="rfc.figure.u.2"></div><pre class="inline"><span id="rfc.iref.g.1"></span><span id="rfc.iref.g.2"></span>  <a href="#abnf.dependencies" class="smpl">challenge</a>   = &lt;challenge, defined in <a href="#RFC2617" id="rfc.xref.RFC2617.3"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>, <a href="http://tools.ietf.org/html/rfc2617#section-1.2">Section 1.2</a>&gt;
589  <a href="#abnf.dependencies" class="smpl">credentials</a> = &lt;credentials, defined in <a href="#RFC2617" id="rfc.xref.RFC2617.4"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>, <a href="http://tools.ietf.org/html/rfc2617#section-1.2">Section 1.2</a>&gt;
590</pre><h1 id="rfc.section.2"><a href="#rfc.section.2">2.</a>&nbsp;Status Code Definitions
591      </h1>
592      <div id="rfc.iref.2"></div>
593      <div id="rfc.iref.s.1"></div>
594      <h2 id="rfc.section.2.1"><a href="#rfc.section.2.1">2.1</a>&nbsp;<a id="status.401" href="#status.401">401 Unauthorized</a></h2>
595      <p id="rfc.section.2.1.p.1">The request requires user authentication. The response <em class="bcp14">MUST</em> include a WWW-Authenticate header field (<a href="#header.www-authenticate" id="rfc.xref.header.www-authenticate.1" title="WWW-Authenticate">Section&nbsp;3.4</a>) containing a challenge applicable to the requested resource. The client <em class="bcp14">MAY</em> repeat the request with a suitable Authorization header field (<a href="#header.authorization" id="rfc.xref.header.authorization.1" title="Authorization">Section&nbsp;3.1</a>). If the request already included Authorization credentials, then the 401 response indicates that authorization has been
596         refused for those credentials. If the 401 response contains the same challenge as the prior response, and the user agent has
597         already attempted authentication at least once, then the user <em class="bcp14">SHOULD</em> be presented the entity that was given in the response, since that entity might include relevant diagnostic information. HTTP
598         access authentication is explained in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.5"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>.
599      </p>
600      <div id="rfc.iref.3"></div>
601      <div id="rfc.iref.s.2"></div>
602      <h2 id="rfc.section.2.2"><a href="#rfc.section.2.2">2.2</a>&nbsp;<a id="status.407" href="#status.407">407 Proxy Authentication Required</a></h2>
603      <p id="rfc.section.2.2.p.1">This code is similar to 401 (Unauthorized), but indicates that the client must first authenticate itself with the proxy. The
604         proxy <em class="bcp14">MUST</em> return a Proxy-Authenticate header field (<a href="#header.proxy-authenticate" id="rfc.xref.header.proxy-authenticate.1" title="Proxy-Authenticate">Section&nbsp;3.2</a>) containing a challenge applicable to the proxy for the requested resource. The client <em class="bcp14">MAY</em> repeat the request with a suitable Proxy-Authorization header field (<a href="#header.proxy-authorization" id="rfc.xref.header.proxy-authorization.1" title="Proxy-Authorization">Section&nbsp;3.3</a>). HTTP access authentication is explained in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.6"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>.
605      </p>
606      <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a id="header.fields" href="#header.fields">Header Field Definitions</a></h1>
607      <p id="rfc.section.3.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to authentication.</p>
608      <div id="rfc.iref.a.1"></div>
609      <div id="rfc.iref.h.1"></div>
610      <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a>&nbsp;<a id="header.authorization" href="#header.authorization">Authorization</a></h2>
611      <p id="rfc.section.3.1.p.1">A user agent that wishes to authenticate itself with a server-- usually, but not necessarily, after receiving a 401 response--does
612         so by including an Authorization request-header field with the request. The field "Authorization" consists of credentials
613         containing the authentication information of the user agent for the realm of the resource being requested.
614      </p>
615      <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.3"></span><span id="rfc.iref.g.4"></span>  <a href="#header.authorization" class="smpl">Authorization</a>   = "Authorization" ":" <a href="#core.rules" class="smpl">OWS</a> <a href="#header.authorization" class="smpl">Authorization-v</a>
616  <a href="#header.authorization" class="smpl">Authorization-v</a> = <a href="#abnf.dependencies" class="smpl">credentials</a>
617</pre><p id="rfc.section.3.1.p.3">HTTP access authentication is described in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.7"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. If a request is authenticated and a realm specified, the same credentials <em class="bcp14">SHOULD</em> be valid for all other requests within this realm (assuming that the authentication scheme itself does not require otherwise,
618         such as credentials that vary according to a challenge value or using synchronized clocks).
619      </p>
620      <p id="rfc.section.3.1.p.4">When a shared cache (see <a href="p6-cache.html#shared.and.non-shared.caches" title="Shared and Non-Shared Caches">Section 8</a> of <a href="#Part6" id="rfc.xref.Part6.1"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) receives a request containing an Authorization field, it <em class="bcp14">MUST NOT</em> return the corresponding response as a reply to any other request, unless one of the following specific exceptions holds:
621      </p>
622      <p id="rfc.section.3.1.p.5"> </p>
623      <ol>
624         <li>If the response includes the "s-maxage" cache-control directive, the cache <em class="bcp14">MAY</em> use that response in replying to a subsequent request. But (if the specified maximum age has passed) a proxy cache <em class="bcp14">MUST</em> first revalidate it with the origin server, using the request-headers from the new request to allow the origin server to authenticate
625            the new request. (This is the defined behavior for s-maxage.) If the response includes "s-maxage=0", the proxy <em class="bcp14">MUST</em> always revalidate it before re-using it.
626         </li>
627         <li>If the response includes the "must-revalidate" cache-control directive, the cache <em class="bcp14">MAY</em> use that response in replying to a subsequent request. But if the response is stale, all caches <em class="bcp14">MUST</em> first revalidate it with the origin server, using the request-headers from the new request to allow the origin server to authenticate
628            the new request.
629         </li>
630         <li>If the response includes the "public" cache-control directive, it <em class="bcp14">MAY</em> be returned in reply to any subsequent request.
631         </li>
632      </ol>
633      <div id="rfc.iref.p.1"></div>
634      <div id="rfc.iref.h.2"></div>
635      <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a>&nbsp;<a id="header.proxy-authenticate" href="#header.proxy-authenticate">Proxy-Authenticate</a></h2>
636      <p id="rfc.section.3.2.p.1">The response-header field "Proxy-Authenticate" <em class="bcp14">MUST</em> be included as part of a 407 (Proxy Authentication Required) response. The field value consists of a challenge that indicates
637         the authentication scheme and parameters applicable to the proxy for this request-target.
638      </p>
639      <div id="rfc.figure.u.4"></div><pre class="inline"><span id="rfc.iref.g.5"></span><span id="rfc.iref.g.6"></span>  <a href="#header.proxy-authenticate" class="smpl">Proxy-Authenticate</a>   = "Proxy-Authenticate" ":" <a href="#core.rules" class="smpl">OWS</a>
640                         <a href="#header.proxy-authenticate" class="smpl">Proxy-Authenticate-v</a>
641  <a href="#header.proxy-authenticate" class="smpl">Proxy-Authenticate-v</a> = 1#<a href="#abnf.dependencies" class="smpl">challenge</a>
642</pre><p id="rfc.section.3.2.p.3">The HTTP access authentication process is described in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.8"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. Unlike WWW-Authenticate, the Proxy-Authenticate header field applies only to the current connection and <em class="bcp14">SHOULD NOT</em> be passed on to downstream clients. However, an intermediate proxy might need to obtain its own credentials by requesting
643         them from the downstream client, which in some circumstances will appear as if the proxy is forwarding the Proxy-Authenticate
644         header field.
645      </p>
646      <div id="rfc.iref.p.2"></div>
647      <div id="rfc.iref.h.3"></div>
648      <h2 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3</a>&nbsp;<a id="header.proxy-authorization" href="#header.proxy-authorization">Proxy-Authorization</a></h2>
649      <p id="rfc.section.3.3.p.1">The request-header field "Proxy-Authorization" allows the client to identify itself (or its user) to a proxy which requires
650         authentication. The Proxy-Authorization field value consists of credentials containing the authentication information of the
651         user agent for the proxy and/or realm of the resource being requested.
652      </p>
653      <div id="rfc.figure.u.5"></div><pre class="inline"><span id="rfc.iref.g.7"></span><span id="rfc.iref.g.8"></span>  <a href="#header.proxy-authorization" class="smpl">Proxy-Authorization</a>   = "Proxy-Authorization" ":" <a href="#core.rules" class="smpl">OWS</a>
654                          <a href="#header.proxy-authorization" class="smpl">Proxy-Authorization-v</a>
655  <a href="#header.proxy-authorization" class="smpl">Proxy-Authorization-v</a> = <a href="#abnf.dependencies" class="smpl">credentials</a>
656</pre><p id="rfc.section.3.3.p.3">The HTTP access authentication process is described in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.9"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. Unlike Authorization, the Proxy-Authorization header field applies only to the next outbound proxy that demanded authentication
657         using the Proxy-Authenticate field. When multiple proxies are used in a chain, the Proxy-Authorization header field is consumed
658         by the first outbound proxy that was expecting to receive credentials. A proxy <em class="bcp14">MAY</em> relay the credentials from the client request to the next proxy if that is the mechanism by which the proxies cooperatively
659         authenticate a given request.
660      </p>
661      <div id="rfc.iref.w.1"></div>
662      <div id="rfc.iref.h.4"></div>
663      <h2 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4</a>&nbsp;<a id="header.www-authenticate" href="#header.www-authenticate">WWW-Authenticate</a></h2>
664      <p id="rfc.section.3.4.p.1">The WWW-Authenticate response-header field <em class="bcp14">MUST</em> be included in 401 (Unauthorized) response messages. The field value consists of at least one challenge that indicates the
665         authentication scheme(s) and parameters applicable to the request-target.
666      </p>
667      <div id="rfc.figure.u.6"></div><pre class="inline"><span id="rfc.iref.g.9"></span><span id="rfc.iref.g.10"></span>  <a href="#header.www-authenticate" class="smpl">WWW-Authenticate</a>   = "WWW-Authenticate" ":" <a href="#core.rules" class="smpl">OWS</a> <a href="#header.www-authenticate" class="smpl">WWW-Authenticate-v</a>
668  <a href="#header.www-authenticate" class="smpl">WWW-Authenticate-v</a> = 1#<a href="#abnf.dependencies" class="smpl">challenge</a>
669</pre><p id="rfc.section.3.4.p.3">The HTTP access authentication process is described in "HTTP Authentication: Basic and Digest Access Authentication" <a href="#RFC2617" id="rfc.xref.RFC2617.10"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. User agents are advised to take special care in parsing the WWW-Authenticate field value as it might contain more than one
670         challenge, or if more than one WWW-Authenticate header field is provided, the contents of a challenge itself can contain a
671         comma-separated list of authentication parameters.
672      </p>
673      <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1>
674      <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a>&nbsp;<a id="message.header.registration" href="#message.header.registration">Message Header Registration</a></h2>
675      <p id="rfc.section.4.1.p.1">The Message Header Registry located at &lt;<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>&gt; should be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>):
676      </p>
677      <div id="rfc.table.1">
678         <div id="iana.header.registration.table"></div>
679         <table summary="" class="tt full" cellpadding="3" cellspacing="0">
680            <thead>
681               <tr>
682                  <th>Header Field Name</th>
683                  <th>Protocol</th>
684                  <th>Status</th>
685                  <th>Reference</th>
686               </tr>
687            </thead>
688            <tbody>
689               <tr>
690                  <td>Authorization</td>
691                  <td>http</td>
692                  <td>standard</td>
693                  <td> <a href="#header.authorization" id="rfc.xref.header.authorization.2" title="Authorization">Section&nbsp;3.1</a>
694                  </td>
695               </tr>
696               <tr>
697                  <td>Proxy-Authenticate</td>
698                  <td>http</td>
699                  <td>standard</td>
700                  <td> <a href="#header.proxy-authenticate" id="rfc.xref.header.proxy-authenticate.2" title="Proxy-Authenticate">Section&nbsp;3.2</a>
701                  </td>
702               </tr>
703               <tr>
704                  <td>Proxy-Authorization</td>
705                  <td>http</td>
706                  <td>standard</td>
707                  <td> <a href="#header.proxy-authorization" id="rfc.xref.header.proxy-authorization.2" title="Proxy-Authorization">Section&nbsp;3.3</a>
708                  </td>
709               </tr>
710               <tr>
711                  <td>WWW-Authenticate</td>
712                  <td>http</td>
713                  <td>standard</td>
714                  <td> <a href="#header.www-authenticate" id="rfc.xref.header.www-authenticate.2" title="WWW-Authenticate">Section&nbsp;3.4</a>
715                  </td>
716               </tr>
717            </tbody>
718         </table>
719      </div>
720      <p id="rfc.section.4.1.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p>
721      <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a id="security.considerations" href="#security.considerations">Security Considerations</a></h1>
722      <p id="rfc.section.5.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1
723         as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does
724         make some suggestions for reducing security risks.
725      </p>
726      <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a>&nbsp;<a id="auth.credentials.and.idle.clients" href="#auth.credentials.and.idle.clients">Authentication Credentials and Idle Clients</a></h2>
727      <p id="rfc.section.5.1.p.1">Existing HTTP clients and user agents typically retain authentication information indefinitely. HTTP/1.1 does not provide
728         a method for a server to direct clients to discard these cached credentials. This is a significant defect that requires further
729         extensions to HTTP. Circumstances under which credential caching can interfere with the application's security model include
730         but are not limited to:
731      </p>
732      <ul>
733         <li>Clients which have been idle for an extended period following which the server might wish to cause the client to reprompt
734            the user for credentials.
735         </li>
736         <li>Applications which include a session termination indication (such as a `logout' or `commit' button on a page) after which
737            the server side of the application `knows' that there is no further reason for the client to retain the credentials.
738         </li>
739      </ul>
740      <p id="rfc.section.5.1.p.2">This is currently under separate study. There are a number of work-arounds to parts of this problem, and we encourage the
741         use of password protection in screen savers, idle time-outs, and other methods which mitigate the security problems inherent
742         in this problem. In particular, user agents which cache credentials are encouraged to provide a readily accessible mechanism
743         for discarding cached credentials under user control.
744      </p>
745      <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a id="ack" href="#ack">Acknowledgments</a></h1>
746      <p id="rfc.section.6.p.1"> <span class="comment">[rfc.comment.1: TBD.]</span>
747      </p>
748      <h1 id="rfc.references"><a id="rfc.section.7" href="#rfc.section.7">7.</a> References
749      </h1>
750      <h2 id="rfc.references.1"><a href="#rfc.section.7.1" id="rfc.section.7.1">7.1</a> Normative References
751      </h2>
752      <table summary="Normative References">         
753         <tr>
754            <td class="reference"><b id="Part1">[Part1]</b></td>
755            <td class="top"><a title="Day Software">Fielding, R., Ed.</a>, <a title="One Laptop per Child">Gettys, J.</a>, <a title="Hewlett-Packard Company">Mogul, J.</a>, <a title="Microsoft Corporation">Frystyk, H.</a>, <a title="Adobe Systems, Incorporated">Masinter, L.</a>, <a title="Microsoft Corporation">Leach, P.</a>, <a title="World Wide Web Consortium">Berners-Lee, T.</a>, <a title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a title="greenbytes GmbH">J. F. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-latest">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p1-messaging-latest (work in progress), February&nbsp;2009.
756            </td>
757         </tr>
758         <tr>
759            <td class="reference"><b id="Part6">[Part6]</b></td>
760            <td class="top"><a title="Day Software">Fielding, R., Ed.</a>, <a title="One Laptop per Child">Gettys, J.</a>, <a title="Hewlett-Packard Company">Mogul, J.</a>, <a title="Microsoft Corporation">Frystyk, H.</a>, <a title="Adobe Systems, Incorporated">Masinter, L.</a>, <a title="Microsoft Corporation">Leach, P.</a>, <a title="World Wide Web Consortium">Berners-Lee, T.</a>, <a title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a title="greenbytes GmbH">J. F. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-latest">HTTP/1.1, part 6: Caching</a>”, Internet-Draft&nbsp;draft-ietf-httpbis-p6-cache-latest (work in progress), February&nbsp;2009.
761            </td>
762         </tr>
763         <tr>
764            <td class="reference"><b id="RFC2119">[RFC2119]</b></td>
765            <td class="top"><a title="Harvard University">Bradner, S.</a>, “<a href="http://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>”, BCP&nbsp;14, RFC&nbsp;2119, March&nbsp;1997.
766            </td>
767         </tr>
768         <tr>
769            <td class="reference"><b id="RFC2617">[RFC2617]</b></td>
770            <td class="top"><a title="Northwestern University, Department of Mathematics">Franks, J.</a>, <a title="Verisign Inc.">Hallam-Baker, P.M.</a>, <a title="AbiSource, Inc.">Hostetler, J.L.</a>, <a title="Agranat Systems, Inc.">Lawrence, S.D.</a>, <a title="Microsoft Corporation">Leach, P.J.</a>, Luotonen, A., and <a title="Open Market, Inc.">L. Stewart</a>, “<a href="http://tools.ietf.org/html/rfc2617">HTTP Authentication: Basic and Digest Access Authentication</a>”, RFC&nbsp;2617, June&nbsp;1999.
771            </td>
772         </tr>
773         <tr>
774            <td class="reference"><b id="RFC5234">[RFC5234]</b></td>
775            <td class="top"><a title="Brandenburg InternetWorking">Crocker, D., Ed.</a> and <a title="THUS plc.">P. Overell</a>, “<a href="http://tools.ietf.org/html/rfc5234">Augmented BNF for Syntax Specifications: ABNF</a>”, STD&nbsp;68, RFC&nbsp;5234, January&nbsp;2008.
776            </td>
777         </tr>
778      </table>
779      <h2 id="rfc.references.2"><a href="#rfc.section.7.2" id="rfc.section.7.2">7.2</a> Informative References
780      </h2>
781      <table summary="Informative References">   
782         <tr>
783            <td class="reference"><b id="RFC2616">[RFC2616]</b></td>
784            <td class="top"><a title="University of California, Irvine">Fielding, R.</a>, <a title="W3C">Gettys, J.</a>, <a title="Compaq Computer Corporation">Mogul, J.</a>, <a title="MIT Laboratory for Computer Science">Frystyk, H.</a>, <a title="Xerox Corporation">Masinter, L.</a>, <a title="Microsoft Corporation">Leach, P.</a>, and <a title="W3C">T. Berners-Lee</a>, “<a href="http://tools.ietf.org/html/rfc2616">Hypertext Transfer Protocol -- HTTP/1.1</a>”, RFC&nbsp;2616, June&nbsp;1999.
785            </td>
786         </tr>
787         <tr>
788            <td class="reference"><b id="RFC3864">[RFC3864]</b></td>
789            <td class="top"><a title="Nine by Nine">Klyne, G.</a>, <a title="BEA Systems">Nottingham, M.</a>, and <a title="HP Labs">J. Mogul</a>, “<a href="http://tools.ietf.org/html/rfc3864">Registration Procedures for Message Header Fields</a>”, BCP&nbsp;90, RFC&nbsp;3864, September&nbsp;2004.
790            </td>
791         </tr>
792      </table>
793      <h1 id="rfc.authors"><a href="#rfc.authors">Authors' Addresses</a></h1>
794      <address class="vcard"><span class="vcardline"><span class="fn">Roy T. Fielding</span>
795            (editor)
796            <span class="n hidden"><span class="family-name">Fielding</span><span class="given-name">Roy T.</span></span></span><span class="org vcardline">Day Software</span><span class="adr"><span class="street-address vcardline">23 Corporate Plaza DR, Suite 280</span><span class="vcardline"><span class="locality">Newport Beach</span>, <span class="region">CA</span>&nbsp;<span class="postal-code">92660</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline tel">Phone: <a href="tel:+1-949-706-5300"><span class="value">+1-949-706-5300</span></a></span><span class="vcardline tel"><span class="type">Fax</span>: <a href="fax:+1-949-706-5305"><span class="value">+1-949-706-5305</span></a></span><span class="vcardline">EMail: <a><span class="email">fielding@gbiv.com</span></a></span><span class="vcardline">URI: <a href="http://roy.gbiv.com/" class="url">http://roy.gbiv.com/</a></span></address>
797      <address class="vcard"><span class="vcardline"><span class="fn">Jim Gettys</span><span class="n hidden"><span class="family-name">Gettys</span><span class="given-name">Jim</span></span></span><span class="org vcardline">One Laptop per Child</span><span class="adr"><span class="street-address vcardline">21 Oak Knoll Road</span><span class="vcardline"><span class="locality">Carlisle</span>, <span class="region">MA</span>&nbsp;<span class="postal-code">01741</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">EMail: <a><span class="email">jg@laptop.org</span></a></span><span class="vcardline">URI: <a href="http://www.laptop.org/" class="url">http://www.laptop.org/</a></span></address>
798      <address class="vcard"><span class="vcardline"><span class="fn">Jeffrey C. Mogul</span><span class="n hidden"><span class="family-name">Mogul</span><span class="given-name">Jeffrey C.</span></span></span><span class="org vcardline">Hewlett-Packard Company</span><span class="adr"><span class="street-address vcardline">HP Labs, Large Scale Systems Group</span><span class="street-address vcardline">1501 Page Mill Road, MS 1177</span><span class="vcardline"><span class="locality">Palo Alto</span>, <span class="region">CA</span>&nbsp;<span class="postal-code">94304</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">EMail: <a><span class="email">JeffMogul@acm.org</span></a></span></address>
799      <address class="vcard"><span class="vcardline"><span class="fn">Henrik Frystyk Nielsen</span><span class="n hidden"><span class="family-name">Frystyk</span></span></span><span class="org vcardline">Microsoft Corporation</span><span class="adr"><span class="street-address vcardline">1 Microsoft Way</span><span class="vcardline"><span class="locality">Redmond</span>, <span class="region">WA</span>&nbsp;<span class="postal-code">98052</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">EMail: <a><span class="email">henrikn@microsoft.com</span></a></span></address>
800      <address class="vcard"><span class="vcardline"><span class="fn">Larry Masinter</span><span class="n hidden"><span class="family-name">Masinter</span><span class="given-name">Larry</span></span></span><span class="org vcardline">Adobe Systems, Incorporated</span><span class="adr"><span class="street-address vcardline">345 Park Ave</span><span class="vcardline"><span class="locality">San Jose</span>, <span class="region">CA</span>&nbsp;<span class="postal-code">95110</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">EMail: <a><span class="email">LMM@acm.org</span></a></span><span class="vcardline">URI: <a href="http://larry.masinter.net/" class="url">http://larry.masinter.net/</a></span></address>
801      <address class="vcard"><span class="vcardline"><span class="fn">Paul J. Leach</span><span class="n hidden"><span class="family-name">Leach</span><span class="given-name">Paul J.</span></span></span><span class="org vcardline">Microsoft Corporation</span><span class="adr"><span class="street-address vcardline">1 Microsoft Way</span><span class="vcardline"><span class="locality">Redmond</span>, <span class="region">WA</span>&nbsp;<span class="postal-code">98052</span></span></span><span class="vcardline">EMail: <a><span class="email">paulle@microsoft.com</span></a></span></address>
802      <address class="vcard"><span class="vcardline"><span class="fn">Tim Berners-Lee</span><span class="n hidden"><span class="family-name">Berners-Lee</span><span class="given-name">Tim</span></span></span><span class="org vcardline">World Wide Web Consortium</span><span class="adr"><span class="street-address vcardline">MIT Computer Science and Artificial Intelligence Laboratory</span><span class="street-address vcardline">The Stata Center, Building 32</span><span class="street-address vcardline">32 Vassar Street</span><span class="vcardline"><span class="locality">Cambridge</span>, <span class="region">MA</span>&nbsp;<span class="postal-code">02139</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">EMail: <a><span class="email">timbl@w3.org</span></a></span><span class="vcardline">URI: <a href="http://www.w3.org/People/Berners-Lee/" class="url">http://www.w3.org/People/Berners-Lee/</a></span></address>
803      <address class="vcard"><span class="vcardline"><span class="fn">Yves Lafon</span>
804            (editor)
805            <span class="n hidden"><span class="family-name">Lafon</span><span class="given-name">Yves</span></span></span><span class="org vcardline">World Wide Web Consortium</span><span class="adr"><span class="street-address vcardline">W3C / ERCIM</span><span class="street-address vcardline">2004, rte des Lucioles</span><span class="vcardline"><span class="locality">Sophia-Antipolis</span>, <span class="region">AM</span>&nbsp;<span class="postal-code">06902</span></span><span class="country-name vcardline">France</span></span><span class="vcardline">EMail: <a><span class="email">ylafon@w3.org</span></a></span><span class="vcardline">URI: <a href="http://www.raubacapeu.net/people/yves/" class="url">http://www.raubacapeu.net/people/yves/</a></span></address>
806      <address class="vcard"><span class="vcardline"><span class="fn">Julian F. Reschke</span>
807            (editor)
808            <span class="n hidden"><span class="family-name">Reschke</span><span class="given-name">Julian F.</span></span></span><span class="org vcardline">greenbytes GmbH</span><span class="adr"><span class="street-address vcardline">Hafenweg 16</span><span class="vcardline"><span class="locality">Muenster</span>, <span class="region">NW</span>&nbsp;<span class="postal-code">48155</span></span><span class="country-name vcardline">Germany</span></span><span class="vcardline tel">Phone: <a href="tel:+492512807760"><span class="value">+49 251 2807760</span></a></span><span class="vcardline tel"><span class="type">Fax</span>: <a href="fax:+492512807761"><span class="value">+49 251 2807761</span></a></span><span class="vcardline">EMail: <a><span class="email">julian.reschke@greenbytes.de</span></a></span><span class="vcardline">URI: <a href="http://greenbytes.de/tech/webdav/" class="url">http://greenbytes.de/tech/webdav/</a></span></address>
809      <h1 id="rfc.section.A"><a href="#rfc.section.A">A.</a>&nbsp;<a id="compatibility" href="#compatibility">Compatibility with Previous Versions</a></h1>
810      <h2 id="rfc.section.A.1"><a href="#rfc.section.A.1">A.1</a>&nbsp;<a id="changes.from.rfc.2616" href="#changes.from.rfc.2616">Changes from RFC 2616</a></h2>
811      <h1 id="rfc.section.B"><a href="#rfc.section.B">B.</a>&nbsp;<a id="collected.abnf" href="#collected.abnf">Collected ABNF</a></h1>
812      <div id="rfc.figure.u.7"></div> <pre class="inline"><a href="#header.authorization" class="smpl">Authorization</a> = "Authorization:" OWS Authorization-v
813<a href="#header.authorization" class="smpl">Authorization-v</a> = credentials
814
815<a href="#core.rules" class="smpl">OWS</a> = &lt;OWS, defined in [Part1], Section 1.2.2&gt;
816
817<a href="#header.proxy-authenticate" class="smpl">Proxy-Authenticate</a> = "Proxy-Authenticate:" OWS Proxy-Authenticate-v
818<a href="#header.proxy-authenticate" class="smpl">Proxy-Authenticate-v</a> = *( "," OWS ) challenge *( OWS "," [ OWS
819 challenge ] )
820<a href="#header.proxy-authorization" class="smpl">Proxy-Authorization</a> = "Proxy-Authorization:" OWS
821 Proxy-Authorization-v
822<a href="#header.proxy-authorization" class="smpl">Proxy-Authorization-v</a> = credentials
823
824<a href="#header.www-authenticate" class="smpl">WWW-Authenticate</a> = "WWW-Authenticate:" OWS WWW-Authenticate-v
825<a href="#header.www-authenticate" class="smpl">WWW-Authenticate-v</a> = *( "," OWS ) challenge *( OWS "," [ OWS
826 challenge ] )
827
828<a href="#abnf.dependencies" class="smpl">challenge</a> = &lt;challenge, defined in [RFC2617], Section 1.2&gt;
829<a href="#abnf.dependencies" class="smpl">credentials</a> = &lt;credentials, defined in [RFC2617], Section 1.2&gt;
830
831
832</pre> <div id="rfc.figure.u.8"></div>
833      <p>ABNF diagnostics:</p><pre class="inline">; Authorization defined but not used
834; Proxy-Authenticate defined but not used
835; Proxy-Authorization defined but not used
836; WWW-Authenticate defined but not used
837</pre><h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a>&nbsp;<a id="change.log" href="#change.log">Change Log (to be removed by RFC Editor before publication)</a></h1>
838      <h2 id="rfc.section.C.1"><a href="#rfc.section.C.1">C.1</a>&nbsp;Since RFC2616
839      </h2>
840      <p id="rfc.section.C.1.p.1">Extracted relevant partitions from <a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>.
841      </p>
842      <h2 id="rfc.section.C.2"><a href="#rfc.section.C.2">C.2</a>&nbsp;Since draft-ietf-httpbis-p7-auth-00
843      </h2>
844      <p id="rfc.section.C.2.p.1">Closed issues: </p>
845      <ul>
846         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/35">http://tools.ietf.org/wg/httpbis/trac/ticket/35</a>&gt;: "Normative and Informative references"
847         </li>
848      </ul>
849      <h2 id="rfc.section.C.3"><a href="#rfc.section.C.3">C.3</a>&nbsp;Since draft-ietf-httpbis-p7-auth-01
850      </h2>
851      <p id="rfc.section.C.3.p.1">Ongoing work on ABNF conversion (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>&gt;):
852      </p>
853      <ul>
854         <li>Explicitly import BNF rules for "challenge" and "credentials" from RFC2617.</li>
855         <li>Add explicit references to BNF syntax and rules imported from other parts of the specification.</li>
856      </ul>
857      <h2 id="rfc.section.C.4"><a href="#rfc.section.C.4">C.4</a>&nbsp;<a id="changes.since.02" href="#changes.since.02">Since draft-ietf-httpbis-p7-auth-02</a></h2>
858      <p id="rfc.section.C.4.p.1">Ongoing work on IANA Message Header Registration (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/40">http://tools.ietf.org/wg/httpbis/trac/ticket/40</a>&gt;):
859      </p>
860      <ul>
861         <li>Reference RFC 3984, and update header registrations for headers defined in this document.</li>
862      </ul>
863      <h2 id="rfc.section.C.5"><a href="#rfc.section.C.5">C.5</a>&nbsp;<a id="changes.since.03" href="#changes.since.03">Since draft-ietf-httpbis-p7-auth-03</a></h2>
864      <h2 id="rfc.section.C.6"><a href="#rfc.section.C.6">C.6</a>&nbsp;<a id="changes.since.04" href="#changes.since.04">Since draft-ietf-httpbis-p7-auth-04</a></h2>
865      <p id="rfc.section.C.6.p.1">Ongoing work on ABNF conversion (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>&gt;):
866      </p>
867      <ul>
868         <li>Use "/" instead of "|" for alternatives.</li>
869         <li>Introduce new ABNF rules for "bad" whitespace ("BWS"), optional whitespace ("OWS") and required whitespace ("RWS").</li>
870         <li>Rewrite ABNFs to spell out whitespace rules, factor out header value format definitions.</li>
871      </ul>
872      <h2 id="rfc.section.C.7"><a href="#rfc.section.C.7">C.7</a>&nbsp;<a id="changes.since.05" href="#changes.since.05">Since draft-ietf-httpbis-p7-auth-05</a></h2>
873      <p id="rfc.section.C.7.p.1">Ongoing work on ABNF conversion (&lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>&gt;):
874      </p>
875      <ul>
876         <li>Add appendix containing collected and expanded ABNF, reorganize ABNF introduction.</li>
877      </ul>
878      <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1>
879      <p class="noprint"><a href="#rfc.index.4">4</a> <a href="#rfc.index.A">A</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.H">H</a> <a href="#rfc.index.P">P</a> <a href="#rfc.index.R">R</a> <a href="#rfc.index.S">S</a> <a href="#rfc.index.W">W</a>
880      </p>
881      <div class="print2col">
882         <ul class="ind">
883            <li class="indline0"><a id="rfc.index.4" href="#rfc.index.4"><b>4</b></a><ul class="ind">
884                  <li class="indline1">401 Unauthorized (status code)&nbsp;&nbsp;<a class="iref" href="#rfc.iref.2"><b>2.1</b></a></li>
885                  <li class="indline1">407 Proxy Authentication Required (status code)&nbsp;&nbsp;<a class="iref" href="#rfc.iref.3"><b>2.2</b></a></li>
886               </ul>
887            </li>
888            <li class="indline0"><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul class="ind">
889                  <li class="indline1">Authorization header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.authorization.1">2.1</a>, <a class="iref" href="#rfc.iref.a.1"><b>3.1</b></a>, <a class="iref" href="#rfc.xref.header.authorization.2">4.1</a></li>
890               </ul>
891            </li>
892            <li class="indline0"><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul class="ind">
893                  <li class="indline1"><tt>Grammar</tt>&nbsp;&nbsp;
894                     <ul class="ind">
895                        <li class="indline1"><tt>Authorization</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.3"><b>3.1</b></a></li>
896                        <li class="indline1"><tt>Authorization-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.4"><b>3.1</b></a></li>
897                        <li class="indline1"><tt>challenge</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.1"><b>1.2.2</b></a></li>
898                        <li class="indline1"><tt>credentials</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.2"><b>1.2.2</b></a></li>
899                        <li class="indline1"><tt>Proxy-Authenticate</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.5"><b>3.2</b></a></li>
900                        <li class="indline1"><tt>Proxy-Authenticate-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.6"><b>3.2</b></a></li>
901                        <li class="indline1"><tt>Proxy-Authorization</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.7"><b>3.3</b></a></li>
902                        <li class="indline1"><tt>Proxy-Authorization-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.8"><b>3.3</b></a></li>
903                        <li class="indline1"><tt>WWW-Authenticate</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.9"><b>3.4</b></a></li>
904                        <li class="indline1"><tt>WWW-Authenticate-v</tt>&nbsp;&nbsp;<a class="iref" href="#rfc.iref.g.10"><b>3.4</b></a></li>
905                     </ul>
906                  </li>
907               </ul>
908            </li>
909            <li class="indline0"><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul class="ind">
910                  <li class="indline1">Headers&nbsp;&nbsp;
911                     <ul class="ind">
912                        <li class="indline1">Authorization&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.authorization.1">2.1</a>, <a class="iref" href="#rfc.iref.h.1"><b>3.1</b></a>, <a class="iref" href="#rfc.xref.header.authorization.2">4.1</a></li>
913                        <li class="indline1">Proxy-Authenticate&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.proxy-authenticate.1">2.2</a>, <a class="iref" href="#rfc.iref.h.2"><b>3.2</b></a>, <a class="iref" href="#rfc.xref.header.proxy-authenticate.2">4.1</a></li>
914                        <li class="indline1">Proxy-Authorization&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.proxy-authorization.1">2.2</a>, <a class="iref" href="#rfc.iref.h.3"><b>3.3</b></a>, <a class="iref" href="#rfc.xref.header.proxy-authorization.2">4.1</a></li>
915                        <li class="indline1">WWW-Authenticate&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.www-authenticate.1">2.1</a>, <a class="iref" href="#rfc.iref.h.4"><b>3.4</b></a>, <a class="iref" href="#rfc.xref.header.www-authenticate.2">4.1</a></li>
916                     </ul>
917                  </li>
918               </ul>
919            </li>
920            <li class="indline0"><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul class="ind">
921                  <li class="indline1"><em>Part1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part1.1">1.2</a>, <a class="iref" href="#rfc.xref.Part1.2">1.2.1</a>, <a class="iref" href="#rfc.xref.Part1.3">1.2.1</a>, <a class="iref" href="#Part1"><b>7.1</b></a><ul class="ind">
922                        <li class="indline1"><em>Section 1.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part1.1">1.2</a></li>
923                        <li class="indline1"><em>Section 1.2.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part1.2">1.2.1</a>, <a class="iref" href="#rfc.xref.Part1.3">1.2.1</a></li>
924                     </ul>
925                  </li>
926                  <li class="indline1"><em>Part6</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.1">3.1</a>, <a class="iref" href="#Part6"><b>7.1</b></a><ul class="ind">
927                        <li class="indline1"><em>Section 8</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.Part6.1">3.1</a></li>
928                     </ul>
929                  </li>
930                  <li class="indline1">Proxy-Authenticate header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.proxy-authenticate.1">2.2</a>, <a class="iref" href="#rfc.iref.p.1"><b>3.2</b></a>, <a class="iref" href="#rfc.xref.header.proxy-authenticate.2">4.1</a></li>
931                  <li class="indline1">Proxy-Authorization header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.proxy-authorization.1">2.2</a>, <a class="iref" href="#rfc.iref.p.2"><b>3.3</b></a>, <a class="iref" href="#rfc.xref.header.proxy-authorization.2">4.1</a></li>
932               </ul>
933            </li>
934            <li class="indline0"><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul class="ind">
935                  <li class="indline1"><em>RFC2119</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2119.1">1.1</a>, <a class="iref" href="#RFC2119"><b>7.1</b></a></li>
936                  <li class="indline1"><em>RFC2616</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2616.1">1</a>, <a class="iref" href="#RFC2616"><b>7.2</b></a>, <a class="iref" href="#rfc.xref.RFC2616.2">C.1</a></li>
937                  <li class="indline1"><em>RFC2617</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2617.1">1</a>, <a class="iref" href="#rfc.xref.RFC2617.2">1</a>, <a class="iref" href="#rfc.xref.RFC2617.3">1.2.2</a>, <a class="iref" href="#rfc.xref.RFC2617.4">1.2.2</a>, <a class="iref" href="#rfc.xref.RFC2617.5">2.1</a>, <a class="iref" href="#rfc.xref.RFC2617.6">2.2</a>, <a class="iref" href="#rfc.xref.RFC2617.7">3.1</a>, <a class="iref" href="#rfc.xref.RFC2617.8">3.2</a>, <a class="iref" href="#rfc.xref.RFC2617.9">3.3</a>, <a class="iref" href="#rfc.xref.RFC2617.10">3.4</a>, <a class="iref" href="#RFC2617"><b>7.1</b></a><ul class="ind">
938                        <li class="indline1"><em>Section 1.2</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC2617.3">1.2.2</a>, <a class="iref" href="#rfc.xref.RFC2617.4">1.2.2</a></li>
939                     </ul>
940                  </li>
941                  <li class="indline1"><em>RFC3864</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC3864.1">4.1</a>, <a class="iref" href="#RFC3864"><b>7.2</b></a></li>
942                  <li class="indline1"><em>RFC5234</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5234.1">1.2</a>, <a class="iref" href="#RFC5234"><b>7.1</b></a><ul class="ind">
943                        <li class="indline1"><em>Appendix B.1</em>&nbsp;&nbsp;<a class="iref" href="#rfc.xref.RFC5234.1">1.2</a></li>
944                     </ul>
945                  </li>
946               </ul>
947            </li>
948            <li class="indline0"><a id="rfc.index.S" href="#rfc.index.S"><b>S</b></a><ul class="ind">
949                  <li class="indline1">Status Codes&nbsp;&nbsp;
950                     <ul class="ind">
951                        <li class="indline1">401 Unauthorized&nbsp;&nbsp;<a class="iref" href="#rfc.iref.s.1"><b>2.1</b></a></li>
952                        <li class="indline1">407 Proxy Authentication Required&nbsp;&nbsp;<a class="iref" href="#rfc.iref.s.2"><b>2.2</b></a></li>
953                     </ul>
954                  </li>
955               </ul>
956            </li>
957            <li class="indline0"><a id="rfc.index.W" href="#rfc.index.W"><b>W</b></a><ul class="ind">
958                  <li class="indline1">WWW-Authenticate header&nbsp;&nbsp;<a class="iref" href="#rfc.xref.header.www-authenticate.1">2.1</a>, <a class="iref" href="#rfc.iref.w.1"><b>3.4</b></a>, <a class="iref" href="#rfc.xref.header.www-authenticate.2">4.1</a></li>
959               </ul>
960            </li>
961         </ul>
962      </div>
963   </body>
964</html>
Note: See TracBrowser for help on using the repository browser.