source: draft-ietf-httpbis/latest/p7-auth.xml @ 1737

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Work-in-progress: hyperlink header field definitions(P7)

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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 "July">
16  <!ENTITY ID-YEAR "2012">
17  <!ENTITY mdash "&#8212;">
18  <!ENTITY Note "<x:h xmlns:x='http://purl.org/net/xml2rfc/ext'>Note:</x:h>">
19  <!ENTITY architecture                 "<xref target='Part1' x:rel='#architecture' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
20  <!ENTITY notation                     "<xref target='Part1' x:rel='#notation' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
21  <!ENTITY abnf-extension               "<xref target='Part1' x:rel='#abnf.extension' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
22  <!ENTITY acks                         "<xref target='Part1' x:rel='#acks' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
23  <!ENTITY whitespace                   "<xref target='Part1' x:rel='#whitespace' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
24  <!ENTITY field-components             "<xref target='Part1' x:rel='#field.components' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
25  <!ENTITY effective-request-uri        "<xref target='Part1' x:rel='#effective.request.uri' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
26  <!ENTITY msg-orient-and-buffering     "<xref target='Part1' x:rel='#intermediaries' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
27  <!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'/>">
28  <!ENTITY status.403                   "<xref target='Part2' x:rel='#status.403' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
29  <!ENTITY shared-and-non-shared-caches "<xref target='Part6' x:rel='#shared.and.non-shared.caches' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
30]>
31<?rfc toc="yes" ?>
32<?rfc symrefs="yes" ?>
33<?rfc sortrefs="yes" ?>
34<?rfc compact="yes"?>
35<?rfc subcompact="no" ?>
36<?rfc linkmailto="no" ?>
37<?rfc editing="no" ?>
38<?rfc comments="yes"?>
39<?rfc inline="yes"?>
40<?rfc rfcedstyle="yes"?>
41<?rfc-ext allow-markup-in-artwork="yes" ?>
42<?rfc-ext include-references-in-index="yes" ?>
43<rfc obsoletes="2616" updates="2617" category="std" x:maturity-level="proposed"
44     ipr="pre5378Trust200902" docName="draft-ietf-httpbis-p7-auth-&ID-VERSION;"
45     xmlns:x='http://purl.org/net/xml2rfc/ext'>
46<x:link rel="prev" basename="p6-cache"/>
47<x:feedback template="mailto:ietf-http-wg@w3.org?subject={docname},%20%22{section}%22&amp;body=&lt;{ref}&gt;:"/>
48<front>
49
50  <title abbrev="HTTP/1.1, Part 7">HTTP/1.1, part 7: Authentication</title>
51
52  <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
53    <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
54    <address>
55      <postal>
56        <street>345 Park Ave</street>
57        <city>San Jose</city>
58        <region>CA</region>
59        <code>95110</code>
60        <country>USA</country>
61      </postal>
62      <email>fielding@gbiv.com</email>
63      <uri>http://roy.gbiv.com/</uri>
64    </address>
65  </author>
66
67  <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
68    <organization abbrev="W3C">World Wide Web Consortium</organization>
69    <address>
70      <postal>
71        <street>W3C / ERCIM</street>
72        <street>2004, rte des Lucioles</street>
73        <city>Sophia-Antipolis</city>
74        <region>AM</region>
75        <code>06902</code>
76        <country>France</country>
77      </postal>
78      <email>ylafon@w3.org</email>
79      <uri>http://www.raubacapeu.net/people/yves/</uri>
80    </address>
81  </author>
82
83  <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
84    <organization abbrev="greenbytes">greenbytes GmbH</organization>
85    <address>
86      <postal>
87        <street>Hafenweg 16</street>
88        <city>Muenster</city><region>NW</region><code>48155</code>
89        <country>Germany</country>
90      </postal>
91      <email>julian.reschke@greenbytes.de</email>
92      <uri>http://greenbytes.de/tech/webdav/</uri>
93    </address>
94  </author>
95
96  <date month="&ID-MONTH;" year="&ID-YEAR;"/>
97  <workgroup>HTTPbis Working Group</workgroup>
98
99<abstract>
100<t>
101   The Hypertext Transfer Protocol (HTTP) is an application-level protocol for
102   distributed, collaborative, hypermedia information systems. HTTP has been in
103   use by the World Wide Web global information initiative since 1990. This
104   document is Part 7 of the seven-part specification that defines the protocol
105   referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616.
106</t>
107<t>
108   Part 7 defines the HTTP Authentication framework.
109</t>
110</abstract>
111
112<note title="Editorial Note (To be removed by RFC Editor)">
113  <t>
114    Discussion of this draft ought to take place on the HTTPBIS working group
115    mailing list (ietf-http-wg@w3.org), which is archived at
116    <eref target="http://lists.w3.org/Archives/Public/ietf-http-wg/"/>.
117  </t>
118  <t>
119    The current issues list is at
120    <eref target="http://tools.ietf.org/wg/httpbis/trac/report/3"/> and related
121    documents (including fancy diffs) can be found at
122    <eref target="http://tools.ietf.org/wg/httpbis/"/>.
123  </t>
124  <t>
125    The changes in this draft are summarized in <xref target="changes.since.19"/>.
126  </t>
127</note>
128</front>
129<middle>
130<section title="Introduction" anchor="introduction">
131<t>
132   This document defines HTTP/1.1 access control and authentication. It
133   includes the relevant parts of <xref target="RFC2616" x:fmt="none">RFC 2616</xref>
134   with only minor changes (<xref target="RFC2616"/>), plus the general framework for HTTP authentication,
135   as previously defined in "HTTP Authentication: Basic and Digest Access
136   Authentication" (<xref target="RFC2617"/>).
137</t>
138<t>
139   HTTP provides several &OPTIONAL; challenge-response authentication
140   mechanisms which can be used by a server to challenge a client request and
141   by a client to provide authentication information. The "basic" and "digest"
142   authentication schemes continue to be specified in
143   <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
144</t>
145
146<section title="Conformance and Error Handling" anchor="intro.conformance.and.error.handling">
147<t>
148   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
149   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
150   document are to be interpreted as described in <xref target="RFC2119"/>.
151</t>
152<t>
153   This document defines conformance criteria for several roles in HTTP
154   communication, including Senders, Recipients, Clients, Servers, User-Agents,
155   Origin Servers, Intermediaries, Proxies and Gateways. See &architecture;
156   for definitions of these terms.
157</t>
158<t>
159   An implementation is considered conformant if it complies with all of the
160   requirements associated with its role(s). Note that SHOULD-level requirements
161   are relevant here, unless one of the documented exceptions is applicable.
162</t>
163<t>
164   This document also uses ABNF to define valid protocol elements
165   (<xref target="notation"/>). In addition to the prose requirements placed
166   upon them, Senders &MUST-NOT; generate protocol elements that are invalid.
167</t>
168<t>
169   Unless noted otherwise, Recipients &MUST; be able to parse all protocol
170   elements matching the ABNF rules defined for them and &MAY; take steps to
171   recover a usable protocol element from an invalid construct. However, HTTP does not define
172   specific error handling mechanisms, except in cases where it has direct
173   impact on security. This is because different uses of the protocol require
174   different error handling strategies; for example, a Web browser might wish to
175   transparently recover from a response where the Location header field
176   doesn't parse according to the ABNF, whereby in a systems control protocol
177   using HTTP, this type of error recovery could lead to dangerous consequences.
178</t>
179</section>
180
181<section title="Syntax Notation" anchor="notation">
182  <x:anchor-alias value="ALPHA"/>
183  <x:anchor-alias value="CR"/>
184  <x:anchor-alias value="DIGIT"/>
185  <x:anchor-alias value="LF"/>
186  <x:anchor-alias value="OCTET"/>
187  <x:anchor-alias value="VCHAR"/>
188  <x:anchor-alias value="SP"/>
189<t>
190   This specification uses the Augmented Backus-Naur Form (ABNF) notation
191   of <xref target="RFC5234"/> with the list rule extension defined in
192   &notation;<xref target="collected.abnf"/> shows the collected ABNF
193   with the list rule expanded.
194</t>
195<t>
196  The following core rules are included by
197  reference, as defined in <xref target="RFC5234" x:fmt="," x:sec="B.1"/>:
198  ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls),
199  DIGIT (decimal 0-9), DQUOTE (double quote),
200  HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed),
201  OCTET (any 8-bit sequence of data), SP (space), and
202  VCHAR (any visible US-ASCII character).
203</t>
204
205<section title="Core Rules" anchor="core.rules">
206   <x:anchor-alias value="quoted-string"/>
207   <x:anchor-alias value="token"/>
208   <x:anchor-alias value="BWS"/>
209   <x:anchor-alias value="OWS"/>
210<t>
211   The core rules below are defined in <xref target="Part1"/>:
212</t>
213<figure><artwork type="abnf2616">
214  <x:ref>BWS</x:ref>           = &lt;BWS, defined in &whitespace;&gt;
215  <x:ref>OWS</x:ref>           = &lt;OWS, defined in &whitespace;&gt;
216  <x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in &field-components;&gt;
217  <x:ref>token</x:ref>         = &lt;token, defined in &field-components;&gt;
218</artwork></figure>
219</section>
220</section>
221</section>
222
223<section title="Access Authentication Framework" anchor="access.authentication.framework">
224
225<section title="Challenge and Response" anchor="challenge.and.response">
226  <x:anchor-alias value="auth-scheme"/>
227  <x:anchor-alias value="auth-param"/>
228  <x:anchor-alias value="b64token"/>
229  <x:anchor-alias value="challenge"/>
230  <x:anchor-alias value="credentials"/>
231<t>
232   HTTP provides a simple challenge-response authentication mechanism
233   that can be used by a server to challenge a client request and by a
234   client to provide authentication information. It uses an extensible,
235   case-insensitive token to identify the authentication scheme, followed
236   by additional information necessary for achieving authentication via that
237   scheme. The latter can either be a comma-separated list of parameters or a
238   single sequence of characters capable of holding base64-encoded
239   information.
240</t>
241<t>
242   Parameters are name-value pairs where the name is matched case-insensitively,
243   and each parameter name &MUST; only occur once per challenge.
244</t>
245<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"/>
246  auth-scheme    = <x:ref>token</x:ref>
247 
248  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> )
249
250  b64token       = 1*( <x:ref>ALPHA</x:ref> / <x:ref>DIGIT</x:ref> /
251                       "-" / "." / "_" / "~" / "+" / "/" ) *"="
252</artwork></figure>
253<t>
254   The "b64token" syntax allows the 66 unreserved URI characters (<xref target="RFC3986"/>),
255   plus a few others, so that it can hold a base64, base64url (URL and filename
256   safe alphabet), base32, or base16 (hex) encoding, with or without padding, but
257   excluding whitespace (<xref target="RFC4648"/>).
258</t>
259<t>
260   The <x:ref>401 (Unauthorized)</x:ref> response message is used by an origin server
261   to challenge the authorization of a user agent. This response &MUST;
262   include a <x:ref>WWW-Authenticate</x:ref> header field containing at least one
263   challenge applicable to the requested resource.
264</t>
265<t>   
266   The <x:ref>407 (Proxy Authentication Required)</x:ref> response message is
267   used by a proxy to challenge the authorization of a client and &MUST;
268   include a <x:ref>Proxy-Authenticate</x:ref> header field containing at least
269   one challenge applicable to the proxy for the requested resource.
270</t>
271<figure><artwork type="abnf2616"><iref item="challenge" primary="true"/><iref primary="true" item="Grammar" subitem="challenge"/>
272  <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> ) ]
273</artwork></figure>
274<x:note>
275  <t>
276     &Note; User agents will need to take special care in parsing the
277     <x:ref>WWW-Authenticate</x:ref> and <x:ref>Proxy-Authenticate</x:ref>
278     header field values because they can contain more than one challenge, or
279     if more than one of each is provided, since the contents of a challenge
280     can itself contain a comma-separated list of authentication parameters.
281  </t>
282</x:note>
283<x:note>
284  <t>
285     &Note; Many clients fail to parse challenges containing unknown
286     schemes. A workaround for this problem is to list well-supported schemes
287     (such as "basic") first.<!-- see http://greenbytes.de/tech/tc/httpauth/#multibasicunknown2 -->
288  </t>
289</x:note>
290<t>
291   A user agent that wishes to authenticate itself with an origin server
292   &mdash; usually, but not necessarily, after receiving a <x:ref>401 (Unauthorized)</x:ref>
293   &mdash; can do so by including an <x:ref>Authorization</x:ref> header field with the
294   request.
295</t>
296<t>   
297   A client that wishes to authenticate itself with a proxy &mdash; usually,
298   but not necessarily, after receiving a <x:ref>407 (Proxy Authentication Required)</x:ref>
299   &mdash; can do so by including a <x:ref>Proxy-Authorization</x:ref> header field with the
300   request.
301</t>
302<t>
303   Both the <x:ref>Authorization</x:ref> field value and the <x:ref>Proxy-Authorization</x:ref> field value
304   contain the client's credentials for the realm of the resource being
305   requested, based upon a challenge received from the server (possibly at
306   some point in the past). When creating their values, the user agent ought to
307   do so by selecting the challenge with what it considers to be the most
308   secure auth-scheme that it understands, obtaining credentials from the user
309   as appropriate.
310</t>
311<figure><artwork type="abnf2616"><iref item="credentials" primary="true"/><iref primary="true" item="Grammar" subitem="credentials"/>
312  <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> ) ]
313</artwork></figure>
314<t>
315   Upon a request for a protected resource that omits credentials, contains
316   invalid credentials (e.g., a bad password) or partial credentials (e.g.,
317   when the authentication scheme requires more than one round trip), an origin
318   server &SHOULD; return a <x:ref>401 (Unauthorized)</x:ref> response. Such
319   responses &MUST; include a <x:ref>WWW-Authenticate</x:ref> header field
320   containing at least one (possibly new) challenge applicable to the
321   requested resource.
322</t>
323<t>
324   Likewise, upon a request that requires authentication by proxies that omit
325   credentials or contain invalid or partial credentials, a proxy &SHOULD;
326   return a <x:ref>407 (Proxy Authentication Required)</x:ref> response. Such responses
327   &MUST; include a <x:ref>Proxy-Authenticate header</x:ref> field containing a (possibly
328   new) challenge applicable to the proxy.
329</t>
330<t>
331   A server receiving credentials that are valid, but not adequate to gain
332   access, ought to respond with the <x:ref>403 (Forbidden)</x:ref> status code (&status.403;).
333</t>
334<t>
335   The HTTP protocol does not restrict applications to this simple
336   challenge-response mechanism for access authentication. Additional
337   mechanisms &MAY; be used, such as encryption at the transport level or
338   via message encapsulation, and with additional header fields
339   specifying authentication information. However, such additional
340   mechanisms are not defined by this specification.
341</t>
342<t>
343   Proxies &MUST; forward the <x:ref>WWW-Authenticate</x:ref> and
344   <x:ref>Authorization</x:ref> header fields unmodified and follow the rules
345   found in <xref target="header.authorization"/>.
346</t>
347</section>
348
349<section title="Protection Space (Realm)" anchor="protection.space">
350  <iref item="Protection Space"/>
351  <iref item="Realm"/>
352  <iref item="Canonical Root URI"/>
353<t>
354   The authentication parameter realm is reserved for use by authentication
355   schemes that wish to indicate the scope of protection.
356</t>
357<t>
358   A <x:dfn>protection space</x:dfn> is defined by the canonical root URI (the
359   scheme and authority components of the effective request URI; see
360   <xref target="Part1" x:fmt="of" x:rel="#effective.request.uri"/>) of the
361   server being accessed, in combination with the realm value if present.
362   These realms allow the protected resources on a server to be
363   partitioned into a set of protection spaces, each with its own
364   authentication scheme and/or authorization database. The realm value
365   is a string, generally assigned by the origin server, which can have
366   additional semantics specific to the authentication scheme. Note that
367   there can be multiple challenges with the same auth-scheme but
368   different realms.
369</t>
370<t>
371   The protection space determines the domain over which credentials can
372   be automatically applied. If a prior request has been authorized, the
373   same credentials &MAY; be reused for all other requests within that
374   protection space for a period of time determined by the
375   authentication scheme, parameters, and/or user preference. Unless
376   otherwise defined by the authentication scheme, a single protection
377   space cannot extend outside the scope of its server.
378</t>
379<t>
380   For historical reasons, senders &MUST; only use the quoted-string syntax.
381   Recipients might have to support both token and quoted-string syntax for
382   maximum interoperability with existing clients that have been accepting both
383   notations for a long time.
384</t>
385</section>
386
387<section title="Authentication Scheme Registry" anchor="authentication.scheme.registry">
388<t>
389  The HTTP Authentication Scheme Registry defines the name space for the
390  authentication schemes in challenges and credentials.
391</t>
392<t>
393  Registrations &MUST; include the following fields:
394  <list style="symbols">
395    <t>Authentication Scheme Name</t>
396    <t>Pointer to specification text</t>
397    <t>Notes (optional)</t>
398  </list>
399</t>
400<t>
401  Values to be added to this name space require IETF Review
402  (see <xref target="RFC5226" x:fmt="," x:sec="4.1"/>).
403</t>
404<t>
405  The registry itself is maintained at <eref target="http://www.iana.org/assignments/http-authschemes"/>.
406</t>
407
408<section title="Considerations for New Authentication Schemes" anchor="considerations.for.new.authentication.schemes">
409<t>
410  There are certain aspects of the HTTP Authentication Framework that put
411  constraints on how new authentication schemes can work:
412</t>
413<t>
414  <list style="symbols">
415    <x:lt>
416    <t>
417      HTTP authentication is presumed to be stateless: all of the information
418      necessary to authenticate a request &MUST; be provided in the request,
419      rather than be dependent on the server remembering prior requests.
420      Authentication based on, or bound to, the underlying connection is
421      outside the scope of this specification and inherently flawed unless
422      steps are taken to ensure that the connection cannot be used by any
423      party other than the authenticated user
424      (see &msg-orient-and-buffering;).
425    </t>
426    </x:lt>
427    <x:lt>
428    <t>
429      The authentication parameter "realm" is reserved for defining Protection
430      Spaces as defined in <xref target="protection.space"/>. New schemes
431      &MUST-NOT; use it in a way incompatible with that definition.
432    </t>
433    </x:lt>
434    <x:lt>
435    <t>
436      The "b64token" notation was introduced for compatibility with existing
437      authentication schemes and can only be used once per challenge/credentials.
438      New schemes thus ought to use the "auth-param" syntax instead, because
439      otherwise future extensions will be impossible.
440    </t>
441    </x:lt>
442    <x:lt>
443    <t>
444      The parsing of challenges and credentials is defined by this specification,
445      and cannot be modified by new authentication schemes. When the auth-param
446      syntax is used, all parameters ought to support both token and
447      quoted-string syntax, and syntactical constraints ought to be defined on
448      the field value after parsing (i.e., quoted-string processing). This is
449      necessary so that recipients can use a generic parser that applies to
450      all authentication schemes.
451    </t>
452    <t>
453      &Note; The fact that the value syntax for the "realm" parameter
454      is restricted to quoted-string was a bad design choice not to be repeated
455      for new parameters.
456    </t>
457    </x:lt>
458    <x:lt>
459    <t>
460      Definitions of new schemes ought to define the treatment of unknown
461      extension parameters. In general, a "must-ignore" rule is preferable
462      over "must-understand", because otherwise it will be hard to introduce
463      new parameters in the presence of legacy recipients. Furthermore,
464      it's good to describe the policy for defining new parameters (such
465      as "update the specification", or "use this registry").
466    </t>
467    </x:lt>
468    <x:lt>
469    <t>
470      Authentication schemes need to document whether they are usable in
471      origin-server authentication (i.e., using <x:ref>WWW-Authenticate</x:ref>),
472      and/or proxy authentication (i.e., using <x:ref>Proxy-Authenticate</x:ref>).
473    </t>
474    </x:lt>
475    <x:lt>
476    <t>
477      The credentials carried in an <x:ref>Authorization</x:ref> header field are specific to
478      the User Agent, and therefore have the same effect on HTTP caches as the
479      "private" Cache-Control response directive, within the scope of the
480      request they appear in.
481    </t>
482    <t>
483      Therefore, new authentication schemes which choose not to carry
484      credentials in the <x:ref>Authorization</x:ref> header field (e.g., using a newly defined
485      header field) will need to explicitly disallow caching, by mandating the use of
486      either Cache-Control request directives (e.g., "no-store") or response
487      directives (e.g., "private").
488    </t>
489    </x:lt>
490  </list>
491</t>
492</section>
493
494</section>
495
496</section>
497
498<section title="Status Code Definitions" anchor="status.code.definitions">
499<section title="401 Unauthorized" anchor="status.401">
500  <iref primary="true" item="401 Unauthorized (status code)" x:for-anchor=""/>
501  <iref primary="true" item="Status Codes" subitem="401 Unauthorized" x:for-anchor=""/>
502  <x:anchor-alias value="401 (Unauthorized)"/>
503<t>
504   The request requires user authentication. The response &MUST; include a
505   <x:ref>WWW-Authenticate</x:ref> header field (<xref target="header.www-authenticate"/>)
506   containing a challenge applicable to the target resource. The client &MAY;
507   repeat the request with a suitable <x:ref>Authorization</x:ref> header field
508   (<xref target="header.authorization"/>). If the request already included
509   Authorization credentials, then the 401 response indicates that authorization
510   has been refused for those credentials. If the 401 response contains the
511   same challenge as the prior response, and the user agent has already attempted
512   authentication at least once, then the user &SHOULD; be presented the
513   representation that was given in the response, since that representation might
514   include relevant diagnostic information.
515</t>
516</section>
517<section title="407 Proxy Authentication Required" anchor="status.407">
518  <iref primary="true" item="407 Proxy Authentication Required (status code)" x:for-anchor=""/>
519  <iref primary="true" item="Status Codes" subitem="407 Proxy Authentication Required" x:for-anchor=""/>
520  <x:anchor-alias value="407 (Proxy Authentication Required)"/>
521<t>
522   This code is similar to <x:ref>401 (Unauthorized)</x:ref>, but indicates that the
523   client ought to first authenticate itself with the proxy. The proxy &MUST;
524   return a <x:ref>Proxy-Authenticate</x:ref> header field (<xref target="header.proxy-authenticate"/>) containing a
525   challenge applicable to the proxy for the target resource. The
526   client &MAY; repeat the request with a suitable <x:ref>Proxy-Authorization</x:ref>
527   header field (<xref target="header.proxy-authorization"/>).
528</t>
529</section>
530</section>
531
532<section title="Header Field Definitions" anchor="header.field.definitions">
533<t>
534   This section defines the syntax and semantics of HTTP/1.1 header fields
535   related to authentication.
536</t>
537
538<section title="Authorization" anchor="header.authorization">
539  <iref primary="true" item="Authorization header field" x:for-anchor=""/>
540  <iref primary="true" item="Header Fields" subitem="Authorization" x:for-anchor=""/>
541  <x:anchor-alias value="Authorization"/>
542<t>
543   The "Authorization" header field allows a user agent to authenticate
544   itself with a server &mdash; usually, but not necessarily, after receiving a <x:ref>401
545   (Unauthorized)</x:ref> response. Its value consists of credentials containing
546   information of the user agent for the realm of the resource being
547   requested.
548</t>
549<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Authorization"/>
550  <x:ref>Authorization</x:ref> = <x:ref>credentials</x:ref>
551</artwork></figure>
552<t>
553   If a request is
554   authenticated and a realm specified, the same credentials &SHOULD;
555   be valid for all other requests within this realm (assuming that
556   the authentication scheme itself does not require otherwise, such
557   as credentials that vary according to a challenge value or using
558   synchronized clocks).
559</t>
560<t>
561      When a shared cache (see &shared-and-non-shared-caches;) receives a request
562      containing an Authorization field, it &MUST-NOT; return the
563      corresponding response as a reply to any other request, unless one
564      of the following specific exceptions holds:
565</t>
566<t>
567  <list style="numbers">
568      <t>If the response includes the "s-maxage" cache-control
569         directive, the cache &MAY; use that response in replying to a
570         subsequent request. But (if the specified maximum age has
571         passed) a proxy cache &MUST; first revalidate it with the origin
572         server, using the header fields from the new request to allow
573         the origin server to authenticate the new request. (This is the
574         defined behavior for s-maxage.) If the response includes "s-maxage=0",
575         the proxy &MUST; always revalidate it before re-using
576         it.</t>
577
578      <t>If the response includes the "must-revalidate" cache-control
579         directive, the cache &MAY; use that response in replying to a
580         subsequent request. But if the response is stale, all caches
581         &MUST; first revalidate it with the origin server, using the
582         header fields from the new request to allow the origin server
583         to authenticate the new request.</t>
584
585      <t>If the response includes the "public" cache-control directive,
586         it &MAY; be returned in reply to any subsequent request.</t>
587  </list>
588</t>
589</section>
590
591<section title="Proxy-Authenticate" anchor="header.proxy-authenticate">
592  <iref primary="true" item="Proxy-Authenticate header field" x:for-anchor=""/>
593  <iref primary="true" item="Header Fields" subitem="Proxy-Authenticate" x:for-anchor=""/>
594  <x:anchor-alias value="Proxy-Authenticate"/>
595<t>
596   The "Proxy-Authenticate" header field consists of at least one
597   challenge that indicates the authentication scheme(s) and parameters
598   applicable to the proxy for this effective request URI (&effective-request-uri;).
599   It &MUST; be included as part of a <x:ref>407 (Proxy Authentication Required)</x:ref> response.
600</t>
601<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authenticate"/>
602  <x:ref>Proxy-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
603</artwork></figure>
604<t>
605   Unlike <x:ref>WWW-Authenticate</x:ref>, the Proxy-Authenticate header field
606   applies only to the current connection, and intermediaries &SHOULD-NOT;
607   forward it to downstream clients. However, an intermediate proxy might need
608   to obtain its own credentials by requesting them from the downstream client,
609   which in some circumstances will appear as if the proxy is forwarding the
610   Proxy-Authenticate header field.
611</t>
612<t>
613   Note that the parsing considerations for <x:ref>WWW-Authenticate</x:ref>
614   apply to this header field as well; see <xref target="header.www-authenticate"/>
615   for details.
616</t>
617</section>
618
619<section title="Proxy-Authorization" anchor="header.proxy-authorization">
620  <iref primary="true" item="Proxy-Authorization header field" x:for-anchor=""/>
621  <iref primary="true" item="Header Fields" subitem="Proxy-Authorization" x:for-anchor=""/>
622  <x:anchor-alias value="Proxy-Authorization"/>
623<t>
624   The "Proxy-Authorization" header field allows the client to
625   identify itself (or its user) to a proxy which requires
626   authentication. Its value consists of
627   credentials containing the authentication information of the user
628   agent for the proxy and/or realm of the resource being requested.
629</t>
630<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authorization"/>
631  <x:ref>Proxy-Authorization</x:ref> = <x:ref>credentials</x:ref>
632</artwork></figure>
633<t>
634   Unlike <x:ref>Authorization</x:ref>, the Proxy-Authorization header field applies only to
635   the next outbound proxy that demanded authentication using the <x:ref>Proxy-Authenticate</x:ref>
636   field. When multiple proxies are used in a chain, the
637   Proxy-Authorization header field is consumed by the first outbound
638   proxy that was expecting to receive credentials. A proxy &MAY; relay
639   the credentials from the client request to the next proxy if that is
640   the mechanism by which the proxies cooperatively authenticate a given
641   request.
642</t>
643</section>
644
645<section title="WWW-Authenticate" anchor="header.www-authenticate">
646  <iref primary="true" item="WWW-Authenticate header field" x:for-anchor=""/>
647  <iref primary="true" item="Header Fields" subitem="WWW-Authenticate" x:for-anchor=""/>
648  <x:anchor-alias value="WWW-Authenticate"/>
649<t>
650   The "WWW-Authenticate" header field consists of at least one
651   challenge that indicates the authentication scheme(s) and parameters
652   applicable to the effective request URI (&effective-request-uri;).
653</t>
654<t>   
655   It &MUST; be included in <x:ref>401 (Unauthorized)</x:ref> response messages and &MAY; be
656   included in other response messages to indicate that supplying credentials
657   (or different credentials) might affect the response.
658</t>
659<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="WWW-Authenticate"/>
660  <x:ref>WWW-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
661</artwork></figure>
662<t>
663   User agents are advised to take special care in parsing the WWW-Authenticate
664   field value as it might contain more than one challenge,
665   or if more than one WWW-Authenticate header field is provided, the
666   contents of a challenge itself can contain a comma-separated list of
667   authentication parameters.
668</t>
669<figure>
670  <preamble>For instance:</preamble>
671  <artwork type="example">
672  WWW-Authenticate: Newauth realm="apps", type=1,
673                    title="Login to \"apps\"", Basic realm="simple"
674</artwork>
675  <postamble>
676  This header field contains two challenges; one for the "Newauth" scheme
677  with a realm value of "apps", and two additional parameters "type" and
678  "title", and another one for the "Basic" scheme with a realm value of
679  "simple".
680</postamble></figure>
681<x:note>
682  <t>
683    &Note; The challenge grammar production uses the list syntax as
684    well. Therefore, a sequence of comma, whitespace, and comma can be
685    considered both as applying to the preceding challenge, or to be an
686    empty entry in the list of challenges. In practice, this ambiguity
687    does not affect the semantics of the header field value and thus is
688    harmless.
689  </t>
690</x:note>
691</section>
692
693</section>
694
695<section title="IANA Considerations" anchor="IANA.considerations">
696
697<section title="Authenticaton Scheme Registry" anchor="authentication.scheme.registration">
698<t>
699  The registration procedure for HTTP Authentication Schemes is defined by
700  <xref target="authentication.scheme.registry"/> of this document.
701</t>
702<t>
703   The HTTP Method Authentication Scheme shall be created at <eref target="http://www.iana.org/assignments/http-authschemes"/>.
704</t>
705</section>
706
707<section title="Status Code Registration" anchor="status.code.registration">
708<t>
709   The HTTP Status Code Registry located at <eref target="http://www.iana.org/assignments/http-status-codes"/>
710   shall be updated with the registrations below:
711</t>
712<?BEGININC p7-auth.iana-status-codes ?>
713<!--AUTOGENERATED FROM extract-status-code-defs.xslt, do not edit manually-->
714<texttable align="left" suppress-title="true" anchor="iana.status.code.registration.table">
715   <ttcol>Value</ttcol>
716   <ttcol>Description</ttcol>
717   <ttcol>Reference</ttcol>
718   <c>401</c>
719   <c>Unauthorized</c>
720   <c>
721      <xref target="status.401"/>
722   </c>
723   <c>407</c>
724   <c>Proxy Authentication Required</c>
725   <c>
726      <xref target="status.407"/>
727   </c>
728</texttable>
729<!--(END)-->
730<?ENDINC p7-auth.iana-status-codes ?>
731</section>
732
733<section title="Header Field Registration" anchor="header.field.registration">
734<t>
735   The Message Header Field Registry located at <eref target="http://www.iana.org/assignments/message-headers/message-header-index.html"/> shall be updated
736   with the permanent registrations below (see <xref target="RFC3864"/>):
737</t>
738<?BEGININC p7-auth.iana-headers ?>
739<!--AUTOGENERATED FROM extract-header-defs.xslt, do not edit manually-->
740<texttable align="left" suppress-title="true" anchor="iana.header.registration.table">
741   <ttcol>Header Field Name</ttcol>
742   <ttcol>Protocol</ttcol>
743   <ttcol>Status</ttcol>
744   <ttcol>Reference</ttcol>
745
746   <c>Authorization</c>
747   <c>http</c>
748   <c>standard</c>
749   <c>
750      <xref target="header.authorization"/>
751   </c>
752   <c>Proxy-Authenticate</c>
753   <c>http</c>
754   <c>standard</c>
755   <c>
756      <xref target="header.proxy-authenticate"/>
757   </c>
758   <c>Proxy-Authorization</c>
759   <c>http</c>
760   <c>standard</c>
761   <c>
762      <xref target="header.proxy-authorization"/>
763   </c>
764   <c>WWW-Authenticate</c>
765   <c>http</c>
766   <c>standard</c>
767   <c>
768      <xref target="header.www-authenticate"/>
769   </c>
770</texttable>
771<!--(END)-->
772<?ENDINC p7-auth.iana-headers ?>
773<t>
774   The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
775</t>
776</section>
777</section>
778
779<section title="Security Considerations" anchor="security.considerations">
780<t>
781   This section is meant to inform application developers, information
782   providers, and users of the security limitations in HTTP/1.1 as
783   described by this document. The discussion does not include
784   definitive solutions to the problems revealed, though it does make
785   some suggestions for reducing security risks.
786</t>
787
788<section title="Authentication Credentials and Idle Clients" anchor="auth.credentials.and.idle.clients">
789<t>
790   Existing HTTP clients and user agents typically retain authentication
791   information indefinitely. HTTP/1.1 does not provide a method for a
792   server to direct clients to discard these cached credentials. This is
793   a significant defect that requires further extensions to HTTP.
794   Circumstances under which credential caching can interfere with the
795   application's security model include but are not limited to:
796  <list style="symbols">
797     <t>Clients which have been idle for an extended period following
798        which the server might wish to cause the client to reprompt the
799        user for credentials.</t>
800
801     <t>Applications which include a session termination indication
802        (such as a "logout" or "commit" button on a page) after which
803        the server side of the application "knows" that there is no
804        further reason for the client to retain the credentials.</t>
805  </list>
806</t>
807<t>
808   This is currently under separate study. There are a number of work-arounds
809   to parts of this problem, and we encourage the use of
810   password protection in screen savers, idle time-outs, and other
811   methods which mitigate the security problems inherent in this
812   problem. In particular, user agents which cache credentials are
813   encouraged to provide a readily accessible mechanism for discarding
814   cached credentials under user control.
815</t>
816</section>
817
818<section title="Protection Spaces" anchor="protection.spaces">
819<t>
820  Authentication schemes that solely rely on the "realm" mechanism for
821  establishing a protection space will expose credentials to all resources on a
822  server. Clients that have successfully made authenticated requests with a
823  resource can use the same authentication credentials for other resources on
824  the same server. This makes it possible for a different resource to harvest
825  authentication credentials for other resources.
826</t>
827<t>
828  This is of particular concern when a server hosts resources for multiple
829  parties under the same canonical root URI (<xref target="protection.spaces"/>).
830  Possible mitigation strategies include restricting direct access to
831  authentication credentials (i.e., not making the content of the
832  <x:ref>Authorization</x:ref> request header field available), and separating protection
833  spaces by using a different host name for each party.
834</t>
835</section>
836</section>
837
838<section title="Acknowledgments" anchor="acks">
839<t>
840  This specification takes over the definition of the HTTP Authentication
841  Framework, previously defined in <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
842  We thank John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D. Lawrence,
843  Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for their work
844  on that specification. See <xref target="RFC2617" x:fmt="of" x:sec="6"/>
845  for further acknowledgements. 
846</t>
847<t>
848  See &acks; for the Acknowledgments related to this document revision.
849</t>
850</section>
851</middle>
852
853<back>
854
855<references title="Normative References">
856
857<reference anchor="Part1">
858  <front>
859    <title>HTTP/1.1, part 1: URIs, Connections, and Message Parsing</title>
860    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
861      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
862      <address><email>fielding@gbiv.com</email></address>
863    </author>
864    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
865      <organization abbrev="W3C">World Wide Web Consortium</organization>
866      <address><email>ylafon@w3.org</email></address>
867    </author>
868    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
869      <organization abbrev="greenbytes">greenbytes GmbH</organization>
870      <address><email>julian.reschke@greenbytes.de</email></address>
871    </author>
872    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
873  </front>
874  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p1-messaging-&ID-VERSION;"/>
875  <x:source href="p1-messaging.xml" basename="p1-messaging"/>
876</reference>
877
878<reference anchor="Part2">
879  <front>
880    <title>HTTP/1.1, part 2: Message Semantics, Payload and Content Negotiation</title>
881    <author fullname="Roy T. Fielding" initials="R." role="editor" surname="Fielding">
882      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
883      <address><email>fielding@gbiv.com</email></address>
884    </author>
885    <author fullname="Yves Lafon" initials="Y." role="editor" surname="Lafon">
886      <organization abbrev="W3C">World Wide Web Consortium</organization>
887      <address><email>ylafon@w3.org</email></address>
888    </author>
889    <author fullname="Julian F. Reschke" initials="J. F." role="editor" surname="Reschke">
890      <organization abbrev="greenbytes">greenbytes GmbH</organization>
891      <address><email>julian.reschke@greenbytes.de</email></address>
892    </author>
893    <date month="&ID-MONTH;" year="&ID-YEAR;" />
894  </front>
895  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p2-semantics-&ID-VERSION;" />
896  <x:source basename="p2-semantics" href="p2-semantics.xml">
897    <x:defines>403 (Forbidden)</x:defines>
898  </x:source>
899</reference>
900
901<reference anchor="Part6">
902  <front>
903    <title>HTTP/1.1, part 6: Caching</title>
904    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
905      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
906      <address><email>fielding@gbiv.com</email></address>
907    </author>
908    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
909      <organization abbrev="W3C">World Wide Web Consortium</organization>
910      <address><email>ylafon@w3.org</email></address>
911    </author>
912    <author initials="M." surname="Nottingham" fullname="Mark Nottingham" role="editor">
913      <organization>Rackspace</organization>
914      <address><email>mnot@mnot.net</email></address>
915    </author>
916    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
917      <organization abbrev="greenbytes">greenbytes GmbH</organization>
918      <address><email>julian.reschke@greenbytes.de</email></address>
919    </author>
920    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
921  </front>
922  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p6-cache-&ID-VERSION;"/>
923  <x:source href="p6-cache.xml" basename="p6-cache"/>
924</reference>
925
926<reference anchor="RFC2119">
927  <front>
928    <title>Key words for use in RFCs to Indicate Requirement Levels</title>
929    <author initials="S." surname="Bradner" fullname="Scott Bradner">
930      <organization>Harvard University</organization>
931      <address><email>sob@harvard.edu</email></address>
932    </author>
933    <date month="March" year="1997"/>
934  </front>
935  <seriesInfo name="BCP" value="14"/>
936  <seriesInfo name="RFC" value="2119"/>
937</reference>
938
939<reference anchor="RFC5234">
940  <front>
941    <title abbrev="ABNF for Syntax Specifications">Augmented BNF for Syntax Specifications: ABNF</title>
942    <author initials="D." surname="Crocker" fullname="Dave Crocker" role="editor">
943      <organization>Brandenburg InternetWorking</organization>
944      <address>
945        <email>dcrocker@bbiw.net</email>
946      </address> 
947    </author>
948    <author initials="P." surname="Overell" fullname="Paul Overell">
949      <organization>THUS plc.</organization>
950      <address>
951        <email>paul.overell@thus.net</email>
952      </address>
953    </author>
954    <date month="January" year="2008"/>
955  </front>
956  <seriesInfo name="STD" value="68"/>
957  <seriesInfo name="RFC" value="5234"/>
958</reference>
959
960</references>
961
962<references title="Informative References">
963
964<reference anchor="RFC2616">
965  <front>
966    <title>Hypertext Transfer Protocol -- HTTP/1.1</title>
967    <author initials="R." surname="Fielding" fullname="R. Fielding">
968      <organization>University of California, Irvine</organization>
969      <address><email>fielding@ics.uci.edu</email></address>
970    </author>
971    <author initials="J." surname="Gettys" fullname="J. Gettys">
972      <organization>W3C</organization>
973      <address><email>jg@w3.org</email></address>
974    </author>
975    <author initials="J." surname="Mogul" fullname="J. Mogul">
976      <organization>Compaq Computer Corporation</organization>
977      <address><email>mogul@wrl.dec.com</email></address>
978    </author>
979    <author initials="H." surname="Frystyk" fullname="H. Frystyk">
980      <organization>MIT Laboratory for Computer Science</organization>
981      <address><email>frystyk@w3.org</email></address>
982    </author>
983    <author initials="L." surname="Masinter" fullname="L. Masinter">
984      <organization>Xerox Corporation</organization>
985      <address><email>masinter@parc.xerox.com</email></address>
986    </author>
987    <author initials="P." surname="Leach" fullname="P. Leach">
988      <organization>Microsoft Corporation</organization>
989      <address><email>paulle@microsoft.com</email></address>
990    </author>
991    <author initials="T." surname="Berners-Lee" fullname="T. Berners-Lee">
992      <organization>W3C</organization>
993      <address><email>timbl@w3.org</email></address>
994    </author>
995    <date month="June" year="1999"/>
996  </front>
997  <seriesInfo name="RFC" value="2616"/>
998</reference>
999
1000<reference anchor="RFC2617">
1001  <front>
1002    <title abbrev="HTTP Authentication">HTTP Authentication: Basic and Digest Access Authentication</title>
1003    <author initials="J." surname="Franks" fullname="John Franks">
1004      <organization>Northwestern University, Department of Mathematics</organization>
1005      <address><email>john@math.nwu.edu</email></address>
1006    </author>
1007    <author initials="P.M." surname="Hallam-Baker" fullname="Phillip M. Hallam-Baker">
1008      <organization>Verisign Inc.</organization>
1009      <address><email>pbaker@verisign.com</email></address>
1010    </author>
1011    <author initials="J.L." surname="Hostetler" fullname="Jeffery L. Hostetler">
1012      <organization>AbiSource, Inc.</organization>
1013      <address><email>jeff@AbiSource.com</email></address>
1014    </author>
1015    <author initials="S.D." surname="Lawrence" fullname="Scott D. Lawrence">
1016      <organization>Agranat Systems, Inc.</organization>
1017      <address><email>lawrence@agranat.com</email></address>
1018    </author>
1019    <author initials="P.J." surname="Leach" fullname="Paul J. Leach">
1020      <organization>Microsoft Corporation</organization>
1021      <address><email>paulle@microsoft.com</email></address>
1022    </author>
1023    <author initials="A." surname="Luotonen" fullname="Ari Luotonen">
1024      <organization>Netscape Communications Corporation</organization>
1025    </author>
1026    <author initials="L." surname="Stewart" fullname="Lawrence C. Stewart">
1027      <organization>Open Market, Inc.</organization>
1028      <address><email>stewart@OpenMarket.com</email></address>
1029    </author>
1030    <date month="June" year="1999"/>
1031  </front>
1032  <seriesInfo name="RFC" value="2617"/>
1033</reference>
1034
1035<reference anchor='RFC3864'>
1036  <front>
1037    <title>Registration Procedures for Message Header Fields</title>
1038    <author initials='G.' surname='Klyne' fullname='G. Klyne'>
1039      <organization>Nine by Nine</organization>
1040      <address><email>GK-IETF@ninebynine.org</email></address>
1041    </author>
1042    <author initials='M.' surname='Nottingham' fullname='M. Nottingham'>
1043      <organization>BEA Systems</organization>
1044      <address><email>mnot@pobox.com</email></address>
1045    </author>
1046    <author initials='J.' surname='Mogul' fullname='J. Mogul'>
1047      <organization>HP Labs</organization>
1048      <address><email>JeffMogul@acm.org</email></address>
1049    </author>
1050    <date year='2004' month='September' />
1051  </front>
1052  <seriesInfo name='BCP' value='90' />
1053  <seriesInfo name='RFC' value='3864' />
1054</reference>
1055
1056<reference anchor="RFC3986">
1057 <front>
1058  <title abbrev='URI Generic Syntax'>Uniform Resource Identifier (URI): Generic Syntax</title>
1059  <author initials='T.' surname='Berners-Lee' fullname='Tim Berners-Lee'>
1060    <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1061    <address>
1062       <email>timbl@w3.org</email>
1063       <uri>http://www.w3.org/People/Berners-Lee/</uri>
1064    </address>
1065  </author>
1066  <author initials='R.' surname='Fielding' fullname='Roy T. Fielding'>
1067    <organization abbrev="Day Software">Day Software</organization>
1068    <address>
1069      <email>fielding@gbiv.com</email>
1070      <uri>http://roy.gbiv.com/</uri>
1071    </address>
1072  </author>
1073  <author initials='L.' surname='Masinter' fullname='Larry Masinter'>
1074    <organization abbrev="Adobe Systems">Adobe Systems Incorporated</organization>
1075    <address>
1076      <email>LMM@acm.org</email>
1077      <uri>http://larry.masinter.net/</uri>
1078    </address>
1079  </author>
1080  <date month='January' year='2005'></date>
1081 </front>
1082 <seriesInfo name="STD" value="66"/>
1083 <seriesInfo name="RFC" value="3986"/>
1084</reference>
1085
1086<reference anchor="RFC4648">
1087  <front>
1088    <title>The Base16, Base32, and Base64 Data Encodings</title>
1089    <author fullname="S. Josefsson" initials="S." surname="Josefsson"/>
1090    <date year="2006" month="October"/>
1091  </front>
1092  <seriesInfo value="4648" name="RFC"/>
1093</reference>
1094
1095<reference anchor='RFC5226'>
1096  <front>
1097    <title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
1098    <author initials='T.' surname='Narten' fullname='T. Narten'>
1099      <organization>IBM</organization>
1100      <address><email>narten@us.ibm.com</email></address>
1101    </author>
1102    <author initials='H.' surname='Alvestrand' fullname='H. Alvestrand'>
1103      <organization>Google</organization>
1104      <address><email>Harald@Alvestrand.no</email></address>
1105    </author>
1106    <date year='2008' month='May' />
1107  </front>
1108  <seriesInfo name='BCP' value='26' />
1109  <seriesInfo name='RFC' value='5226' />
1110</reference>
1111
1112</references>
1113
1114<section title="Changes from RFCs 2616 and 2617" anchor="changes.from.rfc.2616">
1115<t>
1116  The "realm" parameter isn't required anymore in general; consequently, the
1117  ABNF allows challenges without any auth parameters.
1118  (<xref target="access.authentication.framework"/>)
1119</t>
1120<t>
1121  The "b64token" alternative to auth-param lists has been added for consistency
1122  with legacy authentication schemes such as "Basic".
1123  (<xref target="access.authentication.framework"/>)
1124</t>
1125<t>
1126  Change ABNF productions for header fields to only define the field value.
1127  (<xref target="header.field.definitions"/>)
1128</t>
1129</section>
1130 
1131<?BEGININC p7-auth.abnf-appendix ?>
1132<section xmlns:x="http://purl.org/net/xml2rfc/ext" title="Collected ABNF" anchor="collected.abnf">
1133<figure>
1134<artwork type="abnf" name="p7-auth.parsed-abnf">
1135<x:ref>Authorization</x:ref> = credentials
1136
1137<x:ref>BWS</x:ref> = &lt;BWS, defined in [Part1], Section 3.2.1&gt;
1138
1139<x:ref>OWS</x:ref> = &lt;OWS, defined in [Part1], Section 3.2.1&gt;
1140
1141<x:ref>Proxy-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS
1142 challenge ] )
1143<x:ref>Proxy-Authorization</x:ref> = credentials
1144
1145<x:ref>WWW-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS challenge
1146 ] )
1147
1148<x:ref>auth-param</x:ref> = token BWS "=" BWS ( token / quoted-string )
1149<x:ref>auth-scheme</x:ref> = token
1150
1151<x:ref>b64token</x:ref> = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
1152 *"="
1153
1154<x:ref>challenge</x:ref> = auth-scheme [ 1*SP ( b64token / [ ( "," / auth-param ) *(
1155 OWS "," [ OWS auth-param ] ) ] ) ]
1156<x:ref>credentials</x:ref> = auth-scheme [ 1*SP ( b64token / [ ( "," / auth-param )
1157 *( OWS "," [ OWS auth-param ] ) ] ) ]
1158
1159<x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in [Part1], Section 3.2.4&gt;
1160
1161<x:ref>token</x:ref> = &lt;token, defined in [Part1], Section 3.2.4&gt;
1162</artwork>
1163</figure>
1164<figure><preamble>ABNF diagnostics:</preamble><artwork type="inline">
1165; Authorization defined but not used
1166; Proxy-Authenticate defined but not used
1167; Proxy-Authorization defined but not used
1168; WWW-Authenticate defined but not used
1169</artwork></figure></section>
1170<?ENDINC p7-auth.abnf-appendix ?>
1171
1172<section title="Change Log (to be removed by RFC Editor before publication)"  anchor="change.log">
1173<t>
1174  Changes up to the first Working Group Last Call draft are summarized
1175  in <eref target="http://trac.tools.ietf.org/html/draft-ietf-httpbis-p7-auth-19#appendix-C"/>.
1176</t>
1177
1178<section title="Since draft-ietf-httpbis-p7-auth-19" anchor="changes.since.19">
1179<t>
1180  Closed issues:
1181  <list style="symbols">
1182    <t>
1183      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/348"/>:
1184      "Realms and scope"
1185    </t>
1186    <t>
1187      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/349"/>:
1188      "Strength"
1189    </t>
1190    <t>
1191      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/357"/>:
1192      "Authentication exchanges"
1193    </t>
1194    <t>
1195      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/361"/>:
1196      "ABNF requirements for recipients"
1197    </t>
1198  </list>
1199</t>
1200</section>
1201
1202</section>
1203
1204</back>
1205</rfc>
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