source: draft-ietf-httpbis/latest/p7-auth.xml @ 1537

Last change on this file since 1537 was 1533, checked in by julian.reschke@…, 8 years ago

Note the ambiguity in the Proxy-A and WWW-A ABNF (see #342)

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  • Property svn:mime-type set to text/xml
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1<?xml version="1.0" encoding="utf-8"?>
2<?xml-stylesheet type='text/xsl' href='../myxml2rfc.xslt'?>
3<!DOCTYPE rfc [
4  <!ENTITY MAY "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>MAY</bcp14>">
5  <!ENTITY MUST "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>MUST</bcp14>">
6  <!ENTITY MUST-NOT "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>MUST NOT</bcp14>">
7  <!ENTITY OPTIONAL "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>OPTIONAL</bcp14>">
8  <!ENTITY RECOMMENDED "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>RECOMMENDED</bcp14>">
9  <!ENTITY REQUIRED "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>REQUIRED</bcp14>">
10  <!ENTITY SHALL "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHALL</bcp14>">
11  <!ENTITY SHALL-NOT "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHALL NOT</bcp14>">
12  <!ENTITY SHOULD "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHOULD</bcp14>">
13  <!ENTITY SHOULD-NOT "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHOULD NOT</bcp14>">
14  <!ENTITY ID-VERSION "latest">
15  <!ENTITY ID-MONTH "February">
16  <!ENTITY ID-YEAR "2012">
17  <!ENTITY mdash "&#8212;">
18  <!ENTITY architecture                 "<xref target='Part1' x:rel='#architecture' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
19  <!ENTITY notation                     "<xref target='Part1' x:rel='#notation' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
20  <!ENTITY abnf-extension               "<xref target='Part1' x:rel='#abnf.extension' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
21  <!ENTITY acks                         "<xref target='Part1' x:rel='#acks' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
22  <!ENTITY whitespace                   "<xref target='Part1' x:rel='#whitespace' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
23  <!ENTITY field-components             "<xref target='Part1' x:rel='#field.components' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
24  <!ENTITY effective-request-uri        "<xref target='Part1' x:rel='#effective.request.uri' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
25  <!ENTITY msg-orient-and-buffering     "<xref target='Part1' x:rel='#intermediaries' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
26  <!ENTITY end-to-end.and-hop-by-hop    "<xref target='Part1' x:rel='#end-to-end.and.hop-by-hop.header-fields' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
27  <!ENTITY shared-and-non-shared-caches "<xref target='Part6' x:rel='#shared.and.non-shared.caches' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
28]>
29<?rfc toc="yes" ?>
30<?rfc symrefs="yes" ?>
31<?rfc sortrefs="yes" ?>
32<?rfc compact="yes"?>
33<?rfc subcompact="no" ?>
34<?rfc linkmailto="no" ?>
35<?rfc editing="no" ?>
36<?rfc comments="yes"?>
37<?rfc inline="yes"?>
38<?rfc rfcedstyle="yes"?>
39<?rfc-ext allow-markup-in-artwork="yes" ?>
40<?rfc-ext include-references-in-index="yes" ?>
41<rfc obsoletes="2616" updates="2617" category="std" x:maturity-level="proposed"
42     ipr="pre5378Trust200902" docName="draft-ietf-httpbis-p7-auth-&ID-VERSION;"
43     xmlns:x='http://purl.org/net/xml2rfc/ext'>
44<x:link rel="prev" basename="p6-cache"/>
45<x:feedback template="mailto:ietf-http-wg@w3.org?subject={docname},%20%22{section}%22&amp;body=&lt;{ref}&gt;:"/>
46<front>
47
48  <title abbrev="HTTP/1.1, Part 7">HTTP/1.1, part 7: Authentication</title>
49
50  <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
51    <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
52    <address>
53      <postal>
54        <street>345 Park Ave</street>
55        <city>San Jose</city>
56        <region>CA</region>
57        <code>95110</code>
58        <country>USA</country>
59      </postal>
60      <email>fielding@gbiv.com</email>
61      <uri>http://roy.gbiv.com/</uri>
62    </address>
63  </author>
64
65  <author initials="J." surname="Gettys" fullname="Jim Gettys">
66    <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
67    <address>
68      <postal>
69        <street>21 Oak Knoll Road</street>
70        <city>Carlisle</city>
71        <region>MA</region>
72        <code>01741</code>
73        <country>USA</country>
74      </postal>
75      <email>jg@freedesktop.org</email>
76      <uri>http://gettys.wordpress.com/</uri>
77    </address>
78  </author>
79 
80  <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
81    <organization abbrev="HP">Hewlett-Packard Company</organization>
82    <address>
83      <postal>
84        <street>HP Labs, Large Scale Systems Group</street>
85        <street>1501 Page Mill Road, MS 1177</street>
86        <city>Palo Alto</city>
87        <region>CA</region>
88        <code>94304</code>
89        <country>USA</country>
90      </postal>
91      <email>JeffMogul@acm.org</email>
92    </address>
93  </author>
94
95  <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
96    <organization abbrev="Microsoft">Microsoft Corporation</organization>
97    <address>
98      <postal>
99        <street>1 Microsoft Way</street>
100        <city>Redmond</city>
101        <region>WA</region>
102        <code>98052</code>
103        <country>USA</country>
104      </postal>
105      <email>henrikn@microsoft.com</email>
106    </address>
107  </author>
108
109  <author initials="L." surname="Masinter" fullname="Larry Masinter">
110    <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
111    <address>
112      <postal>
113        <street>345 Park Ave</street>
114        <city>San Jose</city>
115        <region>CA</region>
116        <code>95110</code>
117        <country>USA</country>
118      </postal>
119      <email>LMM@acm.org</email>
120      <uri>http://larry.masinter.net/</uri>
121    </address>
122  </author>
123 
124  <author initials="P." surname="Leach" fullname="Paul J. Leach">
125    <organization abbrev="Microsoft">Microsoft Corporation</organization>
126    <address>
127      <postal>
128        <street>1 Microsoft Way</street>
129        <city>Redmond</city>
130        <region>WA</region>
131        <code>98052</code>
132      </postal>
133      <email>paulle@microsoft.com</email>
134    </address>
135  </author>
136   
137  <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
138    <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
139    <address>
140      <postal>
141        <street>MIT Computer Science and Artificial Intelligence Laboratory</street>
142        <street>The Stata Center, Building 32</street>
143        <street>32 Vassar Street</street>
144        <city>Cambridge</city>
145        <region>MA</region>
146        <code>02139</code>
147        <country>USA</country>
148      </postal>
149      <email>timbl@w3.org</email>
150      <uri>http://www.w3.org/People/Berners-Lee/</uri>
151    </address>
152  </author>
153
154  <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
155    <organization abbrev="W3C">World Wide Web Consortium</organization>
156    <address>
157      <postal>
158        <street>W3C / ERCIM</street>
159        <street>2004, rte des Lucioles</street>
160        <city>Sophia-Antipolis</city>
161        <region>AM</region>
162        <code>06902</code>
163        <country>France</country>
164      </postal>
165      <email>ylafon@w3.org</email>
166      <uri>http://www.raubacapeu.net/people/yves/</uri>
167    </address>
168  </author>
169
170  <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
171    <organization abbrev="greenbytes">greenbytes GmbH</organization>
172    <address>
173      <postal>
174        <street>Hafenweg 16</street>
175        <city>Muenster</city><region>NW</region><code>48155</code>
176        <country>Germany</country>
177      </postal>
178      <phone>+49 251 2807760</phone>
179      <facsimile>+49 251 2807761</facsimile>
180      <email>julian.reschke@greenbytes.de</email>
181      <uri>http://greenbytes.de/tech/webdav/</uri>
182    </address>
183  </author>
184
185  <date month="&ID-MONTH;" year="&ID-YEAR;"/>
186  <workgroup>HTTPbis Working Group</workgroup>
187
188<abstract>
189<t>
190   The Hypertext Transfer Protocol (HTTP) is an application-level protocol for
191   distributed, collaborative, hypermedia information systems. HTTP has been in
192   use by the World Wide Web global information initiative since 1990. This
193   document is Part 7 of the seven-part specification that defines the protocol
194   referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616.
195</t>
196<t>
197   Part 7 defines the HTTP Authentication framework.
198</t>
199</abstract>
200
201<note title="Editorial Note (To be removed by RFC Editor)">
202  <t>
203    Discussion of this draft should take place on the HTTPBIS working group
204    mailing list (ietf-http-wg@w3.org), which is archived at
205    <eref target="http://lists.w3.org/Archives/Public/ietf-http-wg/"/>.
206  </t>
207  <t>
208    The current issues list is at
209    <eref target="http://tools.ietf.org/wg/httpbis/trac/report/3"/> and related
210    documents (including fancy diffs) can be found at
211    <eref target="http://tools.ietf.org/wg/httpbis/"/>.
212  </t>
213  <t>
214    The changes in this draft are summarized in <xref target="changes.since.18"/>.
215  </t>
216</note>
217</front>
218<middle>
219<section title="Introduction" anchor="introduction">
220<t>
221   This document defines HTTP/1.1 access control and authentication. It
222   includes the relevant parts of <xref target="RFC2616" x:fmt="none">RFC 2616</xref>
223   with only minor changes, plus the general framework for HTTP authentication,
224   as previously defined in "HTTP Authentication: Basic and Digest Access
225   Authentication" (<xref target="RFC2617"/>).
226</t>
227<t>
228   HTTP provides several &OPTIONAL; challenge-response authentication
229   mechanisms which can be used by a server to challenge a client request and
230   by a client to provide authentication information. The "basic" and "digest"
231   authentication schemes continue to be specified in
232   <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
233</t>
234
235<section title="Conformance and Error Handling" anchor="intro.conformance.and.error.handling">
236<t>
237   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
238   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
239   document are to be interpreted as described in <xref target="RFC2119"/>.
240</t>
241<t>
242   This document defines conformance criteria for several roles in HTTP
243   communication, including Senders, Recipients, Clients, Servers, User-Agents,
244   Origin Servers, Intermediaries, Proxies and Gateways. See &architecture;
245   for definitions of these terms.
246</t>
247<t>
248   An implementation is considered conformant if it complies with all of the
249   requirements associated with its role(s). Note that SHOULD-level requirements
250   are relevant here, unless one of the documented exceptions is applicable.
251</t>
252<t>
253   This document also uses ABNF to define valid protocol elements
254   (<xref target="notation"/>). In addition to the prose requirements placed
255   upon them, Senders &MUST-NOT; generate protocol elements that are invalid.
256</t>
257<t>
258   Unless noted otherwise, Recipients &MAY; take steps to recover a usable
259   protocol element from an invalid construct. However, HTTP does not define
260   specific error handling mechanisms, except in cases where it has direct
261   impact on security. This is because different uses of the protocol require
262   different error handling strategies; for example, a Web browser may wish to
263   transparently recover from a response where the Location header field
264   doesn't parse according to the ABNF, whereby in a systems control protocol
265   using HTTP, this type of error recovery could lead to dangerous consequences.
266</t>
267</section>
268
269<section title="Syntax Notation" anchor="notation">
270  <x:anchor-alias value="ALPHA"/>
271  <x:anchor-alias value="CR"/>
272  <x:anchor-alias value="DIGIT"/>
273  <x:anchor-alias value="LF"/>
274  <x:anchor-alias value="OCTET"/>
275  <x:anchor-alias value="VCHAR"/>
276  <x:anchor-alias value="SP"/>
277<t>
278   This specification uses the Augmented Backus-Naur Form (ABNF) notation
279   of <xref target="RFC5234"/> with the list rule extension defined in
280   &notation;<xref target="collected.abnf"/> shows the collected ABNF
281   with the list rule expanded.
282</t>
283<t>
284  The following core rules are included by
285  reference, as defined in <xref target="RFC5234" x:fmt="," x:sec="B.1"/>:
286  ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls),
287  DIGIT (decimal 0-9), DQUOTE (double quote),
288  HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed),
289  OCTET (any 8-bit sequence of data), SP (space), and
290  VCHAR (any visible US-ASCII character).
291</t>
292
293<section title="Core Rules" anchor="core.rules">
294   <x:anchor-alias value="quoted-string"/>
295   <x:anchor-alias value="token"/>
296   <x:anchor-alias value="BWS"/>
297   <x:anchor-alias value="OWS"/>
298<t>
299   The core rules below are defined in <xref target="Part1"/>:
300</t>
301<figure><artwork type="abnf2616">
302  <x:ref>BWS</x:ref>           = &lt;BWS, defined in &whitespace;&gt;
303  <x:ref>OWS</x:ref>           = &lt;OWS, defined in &whitespace;&gt;
304  <x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in &field-components;&gt;
305  <x:ref>token</x:ref>         = &lt;token, defined in &field-components;&gt;
306</artwork></figure>
307</section>
308</section>
309</section>
310
311<section title="Access Authentication Framework" anchor="access.authentication.framework">
312
313<section title="Challenge and Response" anchor="challenge.and.response">
314  <x:anchor-alias value="auth-scheme"/>
315  <x:anchor-alias value="auth-param"/>
316  <x:anchor-alias value="b64token"/>
317  <x:anchor-alias value="challenge"/>
318  <x:anchor-alias value="credentials"/>
319<t>
320   HTTP provides a simple challenge-response authentication mechanism
321   that can be used by a server to challenge a client request and by a
322   client to provide authentication information. It uses an extensible,
323   case-insensitive token to identify the authentication scheme, followed
324   by additional information necessary for achieving authentication via that
325   scheme. The latter can either be a comma-separated list of parameters or a
326   single sequence of characters capable of holding base64-encoded
327   information.
328</t>
329<t>
330   Parameters are name-value pairs where the name is matched case-insensitively,
331   and each parameter name &MUST; only occur once per challenge.
332</t>
333<figure><artwork type="abnf2616"><iref item="auth-scheme" primary="true"/><iref item="auth-param" primary="true"/><iref primary="true" item="Grammar" subitem="auth-scheme"/><iref primary="true" item="Grammar" subitem="auth-param"/><iref item="b64token" primary="true"/><iref primary="true" item="Grammar" subitem="b64token"/>
334  auth-scheme    = <x:ref>token</x:ref>
335 
336  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> )
337
338  b64token       = 1*( <x:ref>ALPHA</x:ref> / <x:ref>DIGIT</x:ref> /
339                       "-" / "." / "_" / "~" / "+" / "/" ) *"="
340</artwork></figure>
341<t>
342   The "b64token" syntax allows the 66 unreserved URI characters (<xref target="RFC3986"/>),
343   plus a few others, so that it can hold a base64, base64url (URL and filename
344   safe alphabet), base32, or base16 (hex) encoding, with or without padding, but
345   excluding whitespace (<xref target="RFC4648"/>).
346</t>
347<t>
348   The 401 (Unauthorized) response message is used by an origin server
349   to challenge the authorization of a user agent. This response &MUST;
350   include a WWW-Authenticate header field containing at least one
351   challenge applicable to the requested resource.
352</t>
353<t>   
354   The 407 (Proxy Authentication Required) response message is used by a proxy to
355   challenge the authorization of a client and &MUST; include a Proxy-Authenticate
356   header field containing at least one challenge
357   applicable to the proxy for the requested resource.
358</t>
359<figure><artwork type="abnf2616"><iref item="challenge" primary="true"/><iref primary="true" item="Grammar" subitem="challenge"/>
360  <x:ref>challenge</x:ref>   = <x:ref>auth-scheme</x:ref> [ 1*<x:ref>SP</x:ref> ( <x:ref>b64token</x:ref> / #<x:ref>auth-param</x:ref> ) ]
361</artwork></figure>
362<x:note>
363  <t>
364     <x:h>Note:</x:h> User agents will need to take special care in parsing the
365     WWW-Authenticate and Proxy-Authenticate header field values because they
366     can contain more than one challenge, or if more than one of each is
367     provided, since the contents of a challenge can itself contain a
368     comma-separated list of authentication parameters.
369  </t>
370</x:note>
371<x:note>
372  <t>
373     <x:h>Note:</x:h> Many browsers fail to parse challenges containing unknown
374     schemes. A workaround for this problem is to list well-supported schemes
375     (such as "basic") first.<!-- see http://greenbytes.de/tech/tc/httpauth/#multibasicunknown2 -->
376  </t>
377</x:note>
378<t>
379   A user agent that wishes to authenticate itself with an origin server
380   &mdash; usually, but not necessarily, after receiving a 401 (Unauthorized)
381   &mdash; &MAY; do so by including an Authorization header field with the
382   request.
383</t>
384<t>   
385   A client that wishes to authenticate itself with a proxy &mdash; usually,
386   but not necessarily, after receiving a 407 (Proxy Authentication Required)
387   &mdash; &MAY; do so by including a Proxy-Authorization header field with the
388   request.
389</t>
390<t>   
391   Both the Authorization field value and the Proxy-Authorization field value
392   consist of credentials containing the authentication information of the
393   client for the realm of the resource being requested. The user agent &MUST;
394   choose to use one of the challenges with the strongest auth-scheme it
395   understands and request credentials from the user based upon that challenge.
396</t>
397<figure><artwork type="abnf2616"><iref item="credentials" primary="true"/><iref primary="true" item="Grammar" subitem="credentials"/>
398  <x:ref>credentials</x:ref> = <x:ref>auth-scheme</x:ref> [ 1*<x:ref>SP</x:ref> ( <x:ref>b64token</x:ref> / #<x:ref>auth-param</x:ref> ) ]
399</artwork></figure>
400<t>
401   If the origin server does not wish to accept the credentials sent
402   with a request, it &SHOULD; return a 401 (Unauthorized) response. The
403   response &MUST; include a WWW-Authenticate header field containing at
404   least one (possibly new) challenge applicable to the requested
405   resource.
406</t>
407<t>
408   If a proxy does not accept the credentials sent with a
409   request, it &SHOULD; return a 407 (Proxy Authentication Required). The
410   response &MUST; include a Proxy-Authenticate header field containing a
411   (possibly new) challenge applicable to the proxy for the requested
412   resource.
413</t>
414<t>
415   The HTTP protocol does not restrict applications to this simple
416   challenge-response mechanism for access authentication. Additional
417   mechanisms &MAY; be used, such as encryption at the transport level or
418   via message encapsulation, and with additional header fields
419   specifying authentication information. However, such additional
420   mechanisms are not defined by this specification.
421</t>
422<t>
423   Proxies &MUST; forward the WWW-Authenticate and Authorization headers
424   unmodified and follow the rules found in <xref target="header.authorization"/>.
425</t>
426</section>
427
428<section title="Protection Space (Realm)" anchor="protection.space">
429  <iref item="Protection Space"/>
430  <iref item="Realm"/>
431<t>
432   The authentication parameter realm is reserved for use by authentication
433   schemes that wish to indicate the scope of protection.
434</t>
435<t>
436   A <x:dfn>protection space</x:dfn> is defined by the canonical root URI (the
437   scheme and authority components of the effective request URI; see
438   <xref target="Part1" x:fmt="of" x:rel="#effective.request.uri"/>) of the
439   server being accessed, in combination with the realm value if present.
440   These realms allow the protected resources on a server to be
441   partitioned into a set of protection spaces, each with its own
442   authentication scheme and/or authorization database. The realm value
443   is a string, generally assigned by the origin server, which can have
444   additional semantics specific to the authentication scheme. Note that
445   there can be multiple challenges with the same auth-scheme but
446   different realms.
447</t>
448<t>
449   The protection space determines the domain over which credentials can
450   be automatically applied. If a prior request has been authorized, the
451   same credentials &MAY; be reused for all other requests within that
452   protection space for a period of time determined by the
453   authentication scheme, parameters, and/or user preference. Unless
454   otherwise defined by the authentication scheme, a single protection
455   space cannot extend outside the scope of its server.
456</t>
457<t>
458   For historical reasons, senders &MUST; only use the quoted-string syntax.
459   Recipients might have to support both token and quoted-string syntax for
460   maximum interoperability with existing clients that have been accepting both
461   notations for a long time.
462</t>
463</section>
464
465<section title="Authentication Scheme Registry" anchor="authentication.scheme.registry">
466<t>
467  The HTTP Authentication Scheme Registry defines the name space for the
468  authentication schemes in challenges and credentials.
469</t>
470<t>
471  Registrations &MUST; include the following fields:
472  <list style="symbols">
473    <t>Authentication Scheme Name</t>
474    <t>Pointer to specification text</t>
475    <t>Notes (optional)</t>
476  </list>
477</t>
478<t>
479  Values to be added to this name space are subject to IETF review
480  (<xref target="RFC5226" x:fmt="," x:sec="4.1"/>).
481</t>
482<t>
483  The registry itself is maintained at <eref target="http://www.iana.org/assignments/http-authschemes"/>.
484</t>
485
486<section title="Considerations for New Authentication Schemes" anchor="considerations.for.new.authentication.schemes">
487<t>
488  There are certain aspects of the HTTP Authentication Framework that put
489  constraints on how new authentication schemes can work:
490</t>
491<t>
492  <list style="symbols">
493    <x:lt>
494    <t>
495      HTTP authentication is presumed to be stateless: all of the information
496      necessary to authenticate a request &MUST; be provided in the request,
497      rather than be dependent on the server remembering prior requests.
498      Authentication based on, or bound to, the underlying connection is
499      outside the scope of this specification and inherently flawed unless
500      steps are taken to ensure that the connection cannot be used by any
501      party other than the authenticated user
502      (see &msg-orient-and-buffering;).
503    </t>
504    </x:lt>
505    <x:lt>
506    <t>
507      The authentication parameter "realm" is reserved for defining Protection
508      Spaces as defined in <xref target="protection.space"/>. New schemes
509      &MUST-NOT; use it in a way incompatible with that definition.
510    </t>
511    </x:lt>
512    <x:lt>
513    <t>
514      The "b64token" notation was introduced for compatibility with existing
515      authentication schemes and can only be used once per challenge/credentials.
516      New schemes thus ought to use the "auth-param" syntax instead, because
517      otherwise future extensions will be impossible.
518    </t>
519    </x:lt>
520    <x:lt>
521    <t>
522      The parsing of challenges and credentials is defined by this specification,
523      and cannot be modified by new authentication schemes. When the auth-param
524      syntax is used, all parameters ought to support both token and
525      quoted-string syntax, and syntactical constraints ought to be defined on
526      the field value after parsing (i.e., quoted-string processing). This is
527      necessary so that recipients can use a generic parser that applies to
528      all authentication schemes.
529    </t>
530    <t>
531      <x:h>Note:</x:h> the fact that the value syntax for the "realm" parameter
532      is restricted to quoted-string was a bad design choice not to be repeated
533      for new parameters.
534    </t>
535    </x:lt>
536    <x:lt>
537    <t>
538      Authentication schemes need to document whether they are usable in
539      origin-server authentication (i.e., using WWW-Authenticate), and/or
540      proxy authentication (i.e., using Proxy-Authenticate).
541    </t>
542    </x:lt>
543    <x:lt>
544    <t>
545      The credentials carried in an Authorization header field are specific to
546      the User Agent, and therefore have the same effect on HTTP caches as the
547      "private" Cache-Control response directive, within the scope of the
548      request they appear in.
549    </t>
550    <t>
551      Therefore, new authentication schemes which choose not to carry
552      credentials in the Authorization header (e.g., using a newly defined
553      header) will need to explicitly disallow caching, by mandating the use of
554      either Cache-Control request directives (e.g., "no-store") or response
555      directives (e.g., "private").
556    </t>
557    </x:lt>
558  </list>
559</t>
560</section>
561
562</section>
563
564</section>
565
566<section title="Status Code Definitions" anchor="status.code.definitions">
567<section title="401 Unauthorized" anchor="status.401">
568  <iref primary="true" item="401 Unauthorized (status code)" x:for-anchor=""/>
569  <iref primary="true" item="Status Codes" subitem="401 Unauthorized" x:for-anchor=""/>
570<t>
571   The request requires user authentication. The response &MUST; include a
572   WWW-Authenticate header field (<xref target="header.www-authenticate"/>) containing a challenge
573   applicable to the target resource. The client &MAY; repeat the
574   request with a suitable Authorization header field (<xref target="header.authorization"/>). If
575   the request already included Authorization credentials, then the 401
576   response indicates that authorization has been refused for those
577   credentials. If the 401 response contains the same challenge as the
578   prior response, and the user agent has already attempted
579   authentication at least once, then the user &SHOULD; be presented the
580   representation that was given in the response, since that representation might
581   include relevant diagnostic information.
582</t>
583</section>
584<section title="407 Proxy Authentication Required" anchor="status.407">
585  <iref primary="true" item="407 Proxy Authentication Required (status code)" x:for-anchor=""/>
586  <iref primary="true" item="Status Codes" subitem="407 Proxy Authentication Required" x:for-anchor=""/>
587<t>
588   This code is similar to 401 (Unauthorized), but indicates that the
589   client ought to first authenticate itself with the proxy. The proxy &MUST;
590   return a Proxy-Authenticate header field (<xref target="header.proxy-authenticate"/>) containing a
591   challenge applicable to the proxy for the target resource. The
592   client &MAY; repeat the request with a suitable Proxy-Authorization
593   header field (<xref target="header.proxy-authorization"/>).
594</t>
595</section>
596</section>
597
598<section title="Header Field Definitions" anchor="header.field.definitions">
599<t>
600   This section defines the syntax and semantics of HTTP/1.1 header fields
601   related to authentication.
602</t>
603
604<section title="Authorization" anchor="header.authorization">
605  <iref primary="true" item="Authorization header field" x:for-anchor=""/>
606  <iref primary="true" item="Header Fields" subitem="Authorization" x:for-anchor=""/>
607  <x:anchor-alias value="Authorization"/>
608<t>
609   The "Authorization" header field allows a user agent to authenticate
610   itself with a server &mdash; usually, but not necessarily, after receiving a 401
611   (Unauthorized) response. Its value consists of credentials containing
612   information of the user agent for the realm of the resource being
613   requested.
614</t>
615<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Authorization"/>
616  <x:ref>Authorization</x:ref> = <x:ref>credentials</x:ref>
617</artwork></figure>
618<t>
619   If a request is
620   authenticated and a realm specified, the same credentials &SHOULD;
621   be valid for all other requests within this realm (assuming that
622   the authentication scheme itself does not require otherwise, such
623   as credentials that vary according to a challenge value or using
624   synchronized clocks).
625</t>
626<t>
627      When a shared cache (see &shared-and-non-shared-caches;) receives a request
628      containing an Authorization field, it &MUST-NOT; return the
629      corresponding response as a reply to any other request, unless one
630      of the following specific exceptions holds:
631</t>
632<t>
633  <list style="numbers">
634      <t>If the response includes the "s-maxage" cache-control
635         directive, the cache &MAY; use that response in replying to a
636         subsequent request. But (if the specified maximum age has
637         passed) a proxy cache &MUST; first revalidate it with the origin
638         server, using the header fields from the new request to allow
639         the origin server to authenticate the new request. (This is the
640         defined behavior for s-maxage.) If the response includes "s-maxage=0",
641         the proxy &MUST; always revalidate it before re-using
642         it.</t>
643
644      <t>If the response includes the "must-revalidate" cache-control
645         directive, the cache &MAY; use that response in replying to a
646         subsequent request. But if the response is stale, all caches
647         &MUST; first revalidate it with the origin server, using the
648         header fields from the new request to allow the origin server
649         to authenticate the new request.</t>
650
651      <t>If the response includes the "public" cache-control directive,
652         it &MAY; be returned in reply to any subsequent request.</t>
653  </list>
654</t>
655</section>
656
657<section title="Proxy-Authenticate" anchor="header.proxy-authenticate">
658  <iref primary="true" item="Proxy-Authenticate header field" x:for-anchor=""/>
659  <iref primary="true" item="Header Fields" subitem="Proxy-Authenticate" x:for-anchor=""/>
660  <x:anchor-alias value="Proxy-Authenticate"/>
661<t>
662   The "Proxy-Authenticate" header field consists of a challenge that
663   indicates the authentication scheme and parameters applicable to the proxy
664   for this effective request URI (&effective-request-uri;). It &MUST; be included as part
665   of a 407 (Proxy Authentication Required) response.
666</t>
667<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authenticate"/>
668  <x:ref>Proxy-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
669</artwork></figure>
670<t>
671   Unlike WWW-Authenticate, the Proxy-Authenticate header field applies only to
672   the current connection and &SHOULD-NOT;  be passed on to downstream
673   clients. However, an intermediate proxy might need to obtain its own
674   credentials by requesting them from the downstream client, which in
675   some circumstances will appear as if the proxy is forwarding the
676   Proxy-Authenticate header field.
677</t>
678<t>
679   Note that the parsing considerations for WWW-Authenticate apply to this
680   header field as well; see <xref target="header.www-authenticate"/> for
681   details.
682</t>
683</section>
684
685<section title="Proxy-Authorization" anchor="header.proxy-authorization">
686  <iref primary="true" item="Proxy-Authorization header field" x:for-anchor=""/>
687  <iref primary="true" item="Header Fields" subitem="Proxy-Authorization" x:for-anchor=""/>
688  <x:anchor-alias value="Proxy-Authorization"/>
689<t>
690   The "Proxy-Authorization" header field allows the client to
691   identify itself (or its user) to a proxy which requires
692   authentication. Its value consists of
693   credentials containing the authentication information of the user
694   agent for the proxy and/or realm of the resource being requested.
695</t>
696<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authorization"/>
697  <x:ref>Proxy-Authorization</x:ref> = <x:ref>credentials</x:ref>
698</artwork></figure>
699<t>
700   Unlike Authorization, the Proxy-Authorization header field applies only to
701   the next outbound proxy that demanded authentication using the Proxy-Authenticate
702   field. When multiple proxies are used in a chain, the
703   Proxy-Authorization header field is consumed by the first outbound
704   proxy that was expecting to receive credentials. A proxy &MAY; relay
705   the credentials from the client request to the next proxy if that is
706   the mechanism by which the proxies cooperatively authenticate a given
707   request.
708</t>
709</section>
710
711<section title="WWW-Authenticate" anchor="header.www-authenticate">
712  <iref primary="true" item="WWW-Authenticate header field" x:for-anchor=""/>
713  <iref primary="true" item="Header Fields" subitem="WWW-Authenticate" x:for-anchor=""/>
714  <x:anchor-alias value="WWW-Authenticate"/>
715<t>
716   The "WWW-Authenticate" header field consists of at least one
717   challenge that indicates the authentication scheme(s) and parameters
718   applicable to the effective request URI (&effective-request-uri;).
719</t>
720<t>   
721   It &MUST; be included in 401 (Unauthorized) response messages and &MAY; be
722   included in other response messages to indicate that supplying credentials
723   (or different credentials) might affect the response.
724</t>
725<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="WWW-Authenticate"/>
726  <x:ref>WWW-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
727</artwork></figure>
728<t>
729   User agents are advised to take special care in parsing the WWW-Authenticate
730   field value as it might contain more than one challenge,
731   or if more than one WWW-Authenticate header field is provided, the
732   contents of a challenge itself can contain a comma-separated list of
733   authentication parameters.
734</t>
735<figure>
736  <preamble>For instance:</preamble>
737  <artwork type="example">
738  WWW-Authenticate: Newauth realm="apps", type=1,
739                    title="Login to \"apps\"", Basic realm="simple"
740</artwork>
741  <postamble>
742  This header field contains two challenges; one for the "Newauth" scheme
743  with a realm value of "apps", and two additional parameters "type" and
744  "title", and another one for the "Basic" scheme with a realm value of
745  "simple".
746</postamble></figure>
747<x:note>
748  <t>
749    <x:h>Note:</x:h> The challenge grammar production uses the list syntax as
750    well. Therefore, a sequence of comma, whitespace, and comma can be
751    considered both as applying to the preceding challenge, or to be an
752    empty entry in the list of challenges. In practice, this ambiguity
753    does not affect the semantics of the header field value and thus is
754    harmless.
755  </t>
756</x:note>
757</section>
758
759</section>
760
761<section title="IANA Considerations" anchor="IANA.considerations">
762
763<section title="Authenticaton Scheme Registry" anchor="authentication.scheme.registration">
764<t>
765  The registration procedure for HTTP Authentication Schemes is defined by
766  <xref target="authentication.scheme.registry"/> of this document.
767</t>
768<t>
769   The HTTP Method Authentication Scheme shall be created at <eref target="http://www.iana.org/assignments/http-authschemes"/>.
770</t>
771</section>
772
773<section title="Status Code Registration" anchor="status.code.registration">
774<t>
775   The HTTP Status Code Registry located at <eref target="http://www.iana.org/assignments/http-status-codes"/>
776   shall be updated with the registrations below:
777</t>
778<?BEGININC p7-auth.iana-status-codes ?>
779<!--AUTOGENERATED FROM extract-status-code-defs.xslt, do not edit manually-->
780<texttable align="left" suppress-title="true" anchor="iana.status.code.registration.table">
781   <ttcol>Value</ttcol>
782   <ttcol>Description</ttcol>
783   <ttcol>Reference</ttcol>
784   <c>401</c>
785   <c>Unauthorized</c>
786   <c>
787      <xref target="status.401"/>
788   </c>
789   <c>407</c>
790   <c>Proxy Authentication Required</c>
791   <c>
792      <xref target="status.407"/>
793   </c>
794</texttable>
795<!--(END)-->
796<?ENDINC p7-auth.iana-status-codes ?>
797</section>
798
799<section title="Header Field Registration" anchor="header.field.registration">
800<t>
801   The Message Header Field Registry located at <eref target="http://www.iana.org/assignments/message-headers/message-header-index.html"/> shall be updated
802   with the permanent registrations below (see <xref target="RFC3864"/>):
803</t>
804<?BEGININC p7-auth.iana-headers ?>
805<!--AUTOGENERATED FROM extract-header-defs.xslt, do not edit manually-->
806<texttable align="left" suppress-title="true" anchor="iana.header.registration.table">
807   <ttcol>Header Field Name</ttcol>
808   <ttcol>Protocol</ttcol>
809   <ttcol>Status</ttcol>
810   <ttcol>Reference</ttcol>
811
812   <c>Authorization</c>
813   <c>http</c>
814   <c>standard</c>
815   <c>
816      <xref target="header.authorization"/>
817   </c>
818   <c>Proxy-Authenticate</c>
819   <c>http</c>
820   <c>standard</c>
821   <c>
822      <xref target="header.proxy-authenticate"/>
823   </c>
824   <c>Proxy-Authorization</c>
825   <c>http</c>
826   <c>standard</c>
827   <c>
828      <xref target="header.proxy-authorization"/>
829   </c>
830   <c>WWW-Authenticate</c>
831   <c>http</c>
832   <c>standard</c>
833   <c>
834      <xref target="header.www-authenticate"/>
835   </c>
836</texttable>
837<!--(END)-->
838<?ENDINC p7-auth.iana-headers ?>
839<t>
840   The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
841</t>
842</section>
843</section>
844
845<section title="Security Considerations" anchor="security.considerations">
846<t>
847   This section is meant to inform application developers, information
848   providers, and users of the security limitations in HTTP/1.1 as
849   described by this document. The discussion does not include
850   definitive solutions to the problems revealed, though it does make
851   some suggestions for reducing security risks.
852</t>
853
854<section title="Authentication Credentials and Idle Clients" anchor="auth.credentials.and.idle.clients">
855<t>
856   Existing HTTP clients and user agents typically retain authentication
857   information indefinitely. HTTP/1.1 does not provide a method for a
858   server to direct clients to discard these cached credentials. This is
859   a significant defect that requires further extensions to HTTP.
860   Circumstances under which credential caching can interfere with the
861   application's security model include but are not limited to:
862  <list style="symbols">
863     <t>Clients which have been idle for an extended period following
864        which the server might wish to cause the client to reprompt the
865        user for credentials.</t>
866
867     <t>Applications which include a session termination indication
868        (such as a "logout" or "commit" button on a page) after which
869        the server side of the application "knows" that there is no
870        further reason for the client to retain the credentials.</t>
871  </list>
872</t>
873<t>
874   This is currently under separate study. There are a number of work-arounds
875   to parts of this problem, and we encourage the use of
876   password protection in screen savers, idle time-outs, and other
877   methods which mitigate the security problems inherent in this
878   problem. In particular, user agents which cache credentials are
879   encouraged to provide a readily accessible mechanism for discarding
880   cached credentials under user control.
881</t>
882</section>
883</section>
884
885<section title="Acknowledgments" anchor="acks">
886<t>
887  This specification takes over the definition of the HTTP Authentication
888  Framework, previously defined in <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
889  We thank John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D. Lawrence,
890  Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for their work
891  on that specification. See <xref target="RFC2617" x:fmt="of" x:sec="6"/>
892  for further acknowledgements. 
893</t>
894<t>
895  See &acks; for the Acknowledgments related to this document revision.
896</t>
897</section>
898</middle>
899
900<back>
901
902<references title="Normative References">
903
904<reference anchor="Part1">
905  <front>
906    <title abbrev="HTTP/1.1">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</title>
907    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
908      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
909      <address><email>fielding@gbiv.com</email></address>
910    </author>
911    <author initials="J." surname="Gettys" fullname="Jim Gettys">
912      <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
913      <address><email>jg@freedesktop.org</email></address>
914    </author>
915    <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
916      <organization abbrev="HP">Hewlett-Packard Company</organization>
917      <address><email>JeffMogul@acm.org</email></address>
918    </author>
919    <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
920      <organization abbrev="Microsoft">Microsoft Corporation</organization>
921      <address><email>henrikn@microsoft.com</email></address>
922    </author>
923    <author initials="L." surname="Masinter" fullname="Larry Masinter">
924      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
925      <address><email>LMM@acm.org</email></address>
926    </author>
927    <author initials="P." surname="Leach" fullname="Paul J. Leach">
928      <organization abbrev="Microsoft">Microsoft Corporation</organization>
929      <address><email>paulle@microsoft.com</email></address>
930    </author>
931    <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
932      <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
933      <address><email>timbl@w3.org</email></address>
934    </author>
935    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
936      <organization abbrev="W3C">World Wide Web Consortium</organization>
937      <address><email>ylafon@w3.org</email></address>
938    </author>
939    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
940      <organization abbrev="greenbytes">greenbytes GmbH</organization>
941      <address><email>julian.reschke@greenbytes.de</email></address>
942    </author>
943    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
944  </front>
945  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p1-messaging-&ID-VERSION;"/>
946  <x:source href="p1-messaging.xml" basename="p1-messaging"/>
947</reference>
948
949<reference anchor="Part6">
950  <front>
951    <title abbrev="HTTP/1.1">HTTP/1.1, part 6: Caching</title>
952    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
953      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
954      <address><email>fielding@gbiv.com</email></address>
955    </author>
956    <author initials="J." surname="Gettys" fullname="Jim Gettys">
957      <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
958      <address><email>jg@freedesktop.org</email></address>
959    </author>
960    <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
961      <organization abbrev="HP">Hewlett-Packard Company</organization>
962      <address><email>JeffMogul@acm.org</email></address>
963    </author>
964    <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
965      <organization abbrev="Microsoft">Microsoft Corporation</organization>
966      <address><email>henrikn@microsoft.com</email></address>
967    </author>
968    <author initials="L." surname="Masinter" fullname="Larry Masinter">
969      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
970      <address><email>LMM@acm.org</email></address>
971    </author>
972    <author initials="P." surname="Leach" fullname="Paul J. Leach">
973      <organization abbrev="Microsoft">Microsoft Corporation</organization>
974      <address><email>paulle@microsoft.com</email></address>
975    </author>
976    <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
977      <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
978      <address><email>timbl@w3.org</email></address>
979    </author>
980    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
981      <organization abbrev="W3C">World Wide Web Consortium</organization>
982      <address><email>ylafon@w3.org</email></address>
983    </author>
984    <author initials="M." surname="Nottingham" fullname="Mark Nottingham" role="editor">
985      <organization>Rackspace</organization>
986      <address><email>mnot@mnot.net</email></address>
987    </author>
988    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
989      <organization abbrev="greenbytes">greenbytes GmbH</organization>
990      <address><email>julian.reschke@greenbytes.de</email></address>
991    </author>
992    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
993  </front>
994  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p6-cache-&ID-VERSION;"/>
995  <x:source href="p6-cache.xml" basename="p6-cache"/>
996</reference>
997
998<reference anchor="RFC2119">
999  <front>
1000    <title>Key words for use in RFCs to Indicate Requirement Levels</title>
1001    <author initials="S." surname="Bradner" fullname="Scott Bradner">
1002      <organization>Harvard University</organization>
1003      <address><email>sob@harvard.edu</email></address>
1004    </author>
1005    <date month="March" year="1997"/>
1006  </front>
1007  <seriesInfo name="BCP" value="14"/>
1008  <seriesInfo name="RFC" value="2119"/>
1009</reference>
1010
1011<reference anchor="RFC5234">
1012  <front>
1013    <title abbrev="ABNF for Syntax Specifications">Augmented BNF for Syntax Specifications: ABNF</title>
1014    <author initials="D." surname="Crocker" fullname="Dave Crocker" role="editor">
1015      <organization>Brandenburg InternetWorking</organization>
1016      <address>
1017        <email>dcrocker@bbiw.net</email>
1018      </address> 
1019    </author>
1020    <author initials="P." surname="Overell" fullname="Paul Overell">
1021      <organization>THUS plc.</organization>
1022      <address>
1023        <email>paul.overell@thus.net</email>
1024      </address>
1025    </author>
1026    <date month="January" year="2008"/>
1027  </front>
1028  <seriesInfo name="STD" value="68"/>
1029  <seriesInfo name="RFC" value="5234"/>
1030</reference>
1031
1032</references>
1033
1034<references title="Informative References">
1035
1036<reference anchor="RFC2616">
1037  <front>
1038    <title>Hypertext Transfer Protocol -- HTTP/1.1</title>
1039    <author initials="R." surname="Fielding" fullname="R. Fielding">
1040      <organization>University of California, Irvine</organization>
1041      <address><email>fielding@ics.uci.edu</email></address>
1042    </author>
1043    <author initials="J." surname="Gettys" fullname="J. Gettys">
1044      <organization>W3C</organization>
1045      <address><email>jg@w3.org</email></address>
1046    </author>
1047    <author initials="J." surname="Mogul" fullname="J. Mogul">
1048      <organization>Compaq Computer Corporation</organization>
1049      <address><email>mogul@wrl.dec.com</email></address>
1050    </author>
1051    <author initials="H." surname="Frystyk" fullname="H. Frystyk">
1052      <organization>MIT Laboratory for Computer Science</organization>
1053      <address><email>frystyk@w3.org</email></address>
1054    </author>
1055    <author initials="L." surname="Masinter" fullname="L. Masinter">
1056      <organization>Xerox Corporation</organization>
1057      <address><email>masinter@parc.xerox.com</email></address>
1058    </author>
1059    <author initials="P." surname="Leach" fullname="P. Leach">
1060      <organization>Microsoft Corporation</organization>
1061      <address><email>paulle@microsoft.com</email></address>
1062    </author>
1063    <author initials="T." surname="Berners-Lee" fullname="T. Berners-Lee">
1064      <organization>W3C</organization>
1065      <address><email>timbl@w3.org</email></address>
1066    </author>
1067    <date month="June" year="1999"/>
1068  </front>
1069  <seriesInfo name="RFC" value="2616"/>
1070</reference>
1071
1072<reference anchor="RFC2617">
1073  <front>
1074    <title abbrev="HTTP Authentication">HTTP Authentication: Basic and Digest Access Authentication</title>
1075    <author initials="J." surname="Franks" fullname="John Franks">
1076      <organization>Northwestern University, Department of Mathematics</organization>
1077      <address><email>john@math.nwu.edu</email></address>
1078    </author>
1079    <author initials="P.M." surname="Hallam-Baker" fullname="Phillip M. Hallam-Baker">
1080      <organization>Verisign Inc.</organization>
1081      <address><email>pbaker@verisign.com</email></address>
1082    </author>
1083    <author initials="J.L." surname="Hostetler" fullname="Jeffery L. Hostetler">
1084      <organization>AbiSource, Inc.</organization>
1085      <address><email>jeff@AbiSource.com</email></address>
1086    </author>
1087    <author initials="S.D." surname="Lawrence" fullname="Scott D. Lawrence">
1088      <organization>Agranat Systems, Inc.</organization>
1089      <address><email>lawrence@agranat.com</email></address>
1090    </author>
1091    <author initials="P.J." surname="Leach" fullname="Paul J. Leach">
1092      <organization>Microsoft Corporation</organization>
1093      <address><email>paulle@microsoft.com</email></address>
1094    </author>
1095    <author initials="A." surname="Luotonen" fullname="Ari Luotonen">
1096      <organization>Netscape Communications Corporation</organization>
1097    </author>
1098    <author initials="L." surname="Stewart" fullname="Lawrence C. Stewart">
1099      <organization>Open Market, Inc.</organization>
1100      <address><email>stewart@OpenMarket.com</email></address>
1101    </author>
1102    <date month="June" year="1999"/>
1103  </front>
1104  <seriesInfo name="RFC" value="2617"/>
1105</reference>
1106
1107<reference anchor='RFC3864'>
1108  <front>
1109    <title>Registration Procedures for Message Header Fields</title>
1110    <author initials='G.' surname='Klyne' fullname='G. Klyne'>
1111      <organization>Nine by Nine</organization>
1112      <address><email>GK-IETF@ninebynine.org</email></address>
1113    </author>
1114    <author initials='M.' surname='Nottingham' fullname='M. Nottingham'>
1115      <organization>BEA Systems</organization>
1116      <address><email>mnot@pobox.com</email></address>
1117    </author>
1118    <author initials='J.' surname='Mogul' fullname='J. Mogul'>
1119      <organization>HP Labs</organization>
1120      <address><email>JeffMogul@acm.org</email></address>
1121    </author>
1122    <date year='2004' month='September' />
1123  </front>
1124  <seriesInfo name='BCP' value='90' />
1125  <seriesInfo name='RFC' value='3864' />
1126</reference>
1127
1128<reference anchor="RFC3986">
1129 <front>
1130  <title abbrev='URI Generic Syntax'>Uniform Resource Identifier (URI): Generic Syntax</title>
1131  <author initials='T.' surname='Berners-Lee' fullname='Tim Berners-Lee'>
1132    <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1133    <address>
1134       <email>timbl@w3.org</email>
1135       <uri>http://www.w3.org/People/Berners-Lee/</uri>
1136    </address>
1137  </author>
1138  <author initials='R.' surname='Fielding' fullname='Roy T. Fielding'>
1139    <organization abbrev="Day Software">Day Software</organization>
1140    <address>
1141      <email>fielding@gbiv.com</email>
1142      <uri>http://roy.gbiv.com/</uri>
1143    </address>
1144  </author>
1145  <author initials='L.' surname='Masinter' fullname='Larry Masinter'>
1146    <organization abbrev="Adobe Systems">Adobe Systems Incorporated</organization>
1147    <address>
1148      <email>LMM@acm.org</email>
1149      <uri>http://larry.masinter.net/</uri>
1150    </address>
1151  </author>
1152  <date month='January' year='2005'></date>
1153 </front>
1154 <seriesInfo name="STD" value="66"/>
1155 <seriesInfo name="RFC" value="3986"/>
1156</reference>
1157
1158<reference anchor="RFC4648">
1159  <front>
1160    <title>The Base16, Base32, and Base64 Data Encodings</title>
1161    <author fullname="S. Josefsson" initials="S." surname="Josefsson"/>
1162    <date year="2006" month="October"/>
1163  </front>
1164  <seriesInfo value="4648" name="RFC"/>
1165</reference>
1166
1167<reference anchor='RFC5226'>
1168  <front>
1169    <title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
1170    <author initials='T.' surname='Narten' fullname='T. Narten'>
1171      <organization>IBM</organization>
1172      <address><email>narten@us.ibm.com</email></address>
1173    </author>
1174    <author initials='H.' surname='Alvestrand' fullname='H. Alvestrand'>
1175      <organization>Google</organization>
1176      <address><email>Harald@Alvestrand.no</email></address>
1177    </author>
1178    <date year='2008' month='May' />
1179  </front>
1180  <seriesInfo name='BCP' value='26' />
1181  <seriesInfo name='RFC' value='5226' />
1182</reference>
1183
1184</references>
1185
1186<section title="Changes from RFCs 2616 and 2617" anchor="changes.from.rfc.2616">
1187<t>
1188  The "realm" parameter isn't required anymore in general; consequently, the
1189  ABNF allows challenges without any auth parameters.
1190  (<xref target="access.authentication.framework"/>)
1191</t>
1192<t>
1193  The "b64token" alternative to auth-param lists has been added for consistency
1194  with legacy authentication schemes such as "Basic".
1195  (<xref target="access.authentication.framework"/>)
1196</t>
1197<t>
1198  Change ABNF productions for header fields to only define the field value.
1199  (<xref target="header.field.definitions"/>)
1200</t>
1201</section>
1202 
1203<?BEGININC p7-auth.abnf-appendix ?>
1204<section xmlns:x="http://purl.org/net/xml2rfc/ext" title="Collected ABNF" anchor="collected.abnf">
1205<figure>
1206<artwork type="abnf" name="p7-auth.parsed-abnf">
1207<x:ref>Authorization</x:ref> = credentials
1208
1209<x:ref>BWS</x:ref> = &lt;BWS, defined in [Part1], Section 3.2.1&gt;
1210
1211<x:ref>OWS</x:ref> = &lt;OWS, defined in [Part1], Section 3.2.1&gt;
1212
1213<x:ref>Proxy-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS
1214 challenge ] )
1215<x:ref>Proxy-Authorization</x:ref> = credentials
1216
1217<x:ref>WWW-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS challenge
1218 ] )
1219
1220<x:ref>auth-param</x:ref> = token BWS "=" BWS ( token / quoted-string )
1221<x:ref>auth-scheme</x:ref> = token
1222
1223<x:ref>b64token</x:ref> = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
1224 *"="
1225
1226<x:ref>challenge</x:ref> = auth-scheme [ 1*SP ( b64token / [ ( "," / auth-param ) *(
1227 OWS "," [ OWS auth-param ] ) ] ) ]
1228<x:ref>credentials</x:ref> = auth-scheme [ 1*SP ( b64token / [ ( "," / auth-param )
1229 *( OWS "," [ OWS auth-param ] ) ] ) ]
1230
1231<x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in [Part1], Section 3.2.4&gt;
1232
1233<x:ref>token</x:ref> = &lt;token, defined in [Part1], Section 3.2.4&gt;
1234</artwork>
1235</figure>
1236<figure><preamble>ABNF diagnostics:</preamble><artwork type="inline">
1237; Authorization defined but not used
1238; Proxy-Authenticate defined but not used
1239; Proxy-Authorization defined but not used
1240; WWW-Authenticate defined but not used
1241</artwork></figure></section>
1242<?ENDINC p7-auth.abnf-appendix ?>
1243
1244<section title="Change Log (to be removed by RFC Editor before publication)"  anchor="change.log">
1245
1246<section title="Since RFC 2616">
1247<t>
1248  Extracted relevant partitions from <xref target="RFC2616"/>.
1249</t>
1250</section>
1251
1252<section title="Since draft-ietf-httpbis-p7-auth-00">
1253<t>
1254  Closed issues:
1255  <list style="symbols"> 
1256    <t>
1257      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/35"/>:
1258      "Normative and Informative references"
1259    </t>
1260  </list>
1261</t>
1262</section>
1263
1264<section title="Since draft-ietf-httpbis-p7-auth-01">
1265<t>
1266  Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
1267  <list style="symbols"> 
1268    <t>
1269      Explicitly import BNF rules for "challenge" and "credentials" from RFC2617.
1270    </t>
1271    <t>
1272      Add explicit references to BNF syntax and rules imported from other parts of the specification.
1273    </t>
1274  </list>
1275</t>
1276</section>
1277
1278<section title="Since draft-ietf-httpbis-p7-auth-02" anchor="changes.since.02">
1279<t>
1280  Ongoing work on IANA Message Header Field Registration (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/40"/>):
1281  <list style="symbols"> 
1282    <t>
1283      Reference RFC 3984, and update header field registrations for header fields defined
1284      in this document.
1285    </t>
1286  </list>
1287</t>
1288</section>
1289
1290<section title="Since draft-ietf-httpbis-p7-auth-03" anchor="changes.since.03">
1291<t>
1292  None.
1293</t>
1294</section>
1295
1296<section title="Since draft-ietf-httpbis-p7-auth-04" anchor="changes.since.04">
1297<t>
1298  Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
1299  <list style="symbols"> 
1300    <t>
1301      Use "/" instead of "|" for alternatives.
1302    </t>
1303    <t>
1304      Introduce new ABNF rules for "bad" whitespace ("BWS"), optional
1305      whitespace ("OWS") and required whitespace ("RWS").
1306    </t>
1307    <t>
1308      Rewrite ABNFs to spell out whitespace rules, factor out
1309      header field value format definitions.
1310    </t>
1311  </list>
1312</t>
1313</section>
1314
1315<section title="Since draft-ietf-httpbis-p7-auth-05" anchor="changes.since.05">
1316<t>
1317  Final work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
1318  <list style="symbols"> 
1319    <t>
1320      Add appendix containing collected and expanded ABNF, reorganize ABNF introduction.
1321    </t>
1322  </list>
1323</t>
1324</section>
1325
1326<section title="Since draft-ietf-httpbis-p7-auth-06" anchor="changes.since.06">
1327<t>
1328  None.
1329</t>
1330</section>
1331
1332<section title="Since draft-ietf-httpbis-p7-auth-07" anchor="changes.since.07">
1333<t>
1334  Closed issues:
1335  <list style="symbols"> 
1336    <t>
1337      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/198"/>:
1338      "move IANA registrations for optional status codes"
1339    </t>
1340  </list>
1341</t>
1342</section>
1343
1344<section title="Since draft-ietf-httpbis-p7-auth-08" anchor="changes.since.08">
1345<t>
1346  No significant changes.
1347</t>
1348</section>
1349
1350<section title="Since draft-ietf-httpbis-p7-auth-09" anchor="changes.since.09">
1351<t>
1352  Partly resolved issues:
1353  <list style="symbols"> 
1354    <t>
1355      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/196"/>:
1356      "Term for the requested resource's URI"
1357    </t>
1358  </list>
1359</t>
1360</section>
1361
1362<section title="Since draft-ietf-httpbis-p7-auth-10" anchor="changes.since.10">
1363<t>
1364  None.
1365</t>
1366</section>
1367
1368<section title="Since draft-ietf-httpbis-p7-auth-11" anchor="changes.since.11">
1369<t>
1370  Closed issues:
1371  <list style="symbols"> 
1372    <t>
1373      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/130"/>:
1374      "introduction to part 7 is work-in-progress"
1375    </t>
1376    <t>
1377      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/195"/>:
1378      "auth-param syntax"
1379    </t>
1380    <t>
1381      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/224"/>:
1382      "Header Classification"
1383    </t>
1384    <t>
1385      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/237"/>:
1386      "absorbing the auth framework from 2617"
1387    </t>
1388  </list>
1389</t>
1390<t>
1391  Partly resolved issues:
1392  <list style="symbols"> 
1393    <t>
1394      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/141"/>:
1395      "should we have an auth scheme registry"
1396    </t>
1397  </list>
1398</t>
1399</section>
1400
1401<section title="Since draft-ietf-httpbis-p7-auth-12" anchor="changes.since.12">
1402<t>
1403  None.
1404</t>
1405</section>
1406
1407<section title="Since draft-ietf-httpbis-p7-auth-13" anchor="changes.since.13">
1408<t>
1409  Closed issues:
1410  <list style="symbols">
1411    <t>
1412      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/276"/>:
1413      "untangle ABNFs for header fields"
1414    </t>
1415  </list>
1416</t>
1417</section>
1418
1419<section title="Since draft-ietf-httpbis-p7-auth-14" anchor="changes.since.14">
1420<t>
1421  None.
1422</t>
1423</section>
1424
1425<section title="Since draft-ietf-httpbis-p7-auth-15" anchor="changes.since.15">
1426<t>
1427  Closed issues:
1428  <list style="symbols">
1429    <t>
1430      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/78"/>:
1431      "Relationship between 401, Authorization and WWW-Authenticate"
1432    </t>
1433    <t>
1434      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/177"/>:
1435      "Realm required on challenges"
1436    </t>
1437    <t>
1438      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/195"/>:
1439      "auth-param syntax"
1440    </t>
1441    <t>
1442      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/257"/>:
1443      "Considerations for new authentications schemes"
1444    </t>
1445    <t>
1446      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/287"/>:
1447      "LWS in auth-param ABNF"
1448    </t>
1449    <t>
1450      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/309"/>:
1451      "credentials ABNF missing SP (still using implied LWS?)"
1452    </t>
1453  </list>
1454</t>
1455</section>
1456
1457<section title="Since draft-ietf-httpbis-p7-auth-16" anchor="changes.since.16">
1458<t>
1459  Closed issues:
1460  <list style="symbols"> 
1461    <t>
1462      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/186"/>:
1463      "Document HTTP's error-handling philosophy"
1464    </t>
1465    <t>
1466      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/320"/>:
1467      "add advice on defining auth scheme parameters"
1468    </t>
1469  </list>
1470</t>
1471</section>
1472
1473<section title="Since draft-ietf-httpbis-p7-auth-17" anchor="changes.since.17">
1474<t>
1475  Closed issues:
1476  <list style="symbols"> 
1477    <t>
1478      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/314"/>:
1479      "allow unquoted realm parameters"
1480    </t>
1481    <t>
1482      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/321"/>:
1483      "Repeating auth-params"
1484    </t>
1485  </list>
1486</t>
1487</section>
1488
1489<section title="Since draft-ietf-httpbis-p7-auth-18" anchor="changes.since.18">
1490<t>
1491  Closed issues:
1492  <list style="symbols"> 
1493    <t>
1494      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/342"/>:
1495      "WWW-Authenticate ABNF slightly ambiguous"
1496    </t>
1497  </list>
1498</t>
1499</section>
1500
1501</section>
1502
1503</back>
1504</rfc>
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