source: draft-ietf-httpbis/latest/p7-auth.xml @ 1684

Last change on this file since 1684 was 1684, checked in by julian.reschke@…, 7 years ago

Replace "may" by "might" (see #362)

  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/xml
File size: 49.5 KB
Line 
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 "June">
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="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
66    <organization abbrev="W3C">World Wide Web Consortium</organization>
67    <address>
68      <postal>
69        <street>W3C / ERCIM</street>
70        <street>2004, rte des Lucioles</street>
71        <city>Sophia-Antipolis</city>
72        <region>AM</region>
73        <code>06902</code>
74        <country>France</country>
75      </postal>
76      <email>ylafon@w3.org</email>
77      <uri>http://www.raubacapeu.net/people/yves/</uri>
78    </address>
79  </author>
80
81  <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
82    <organization abbrev="greenbytes">greenbytes GmbH</organization>
83    <address>
84      <postal>
85        <street>Hafenweg 16</street>
86        <city>Muenster</city><region>NW</region><code>48155</code>
87        <country>Germany</country>
88      </postal>
89      <phone>+49 251 2807760</phone>
90      <facsimile>+49 251 2807761</facsimile>
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 should 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 401 (Unauthorized) response message is used by an origin server
261   to challenge the authorization of a user agent. This response &MUST;
262   include a WWW-Authenticate header field containing at least one
263   challenge applicable to the requested resource.
264</t>
265<t>   
266   The 407 (Proxy Authentication Required) response message is used by a proxy to
267   challenge the authorization of a client and &MUST; include a Proxy-Authenticate
268   header field containing at least one challenge
269   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     <x:h>Note:</x:h> User agents will need to take special care in parsing the
277     WWW-Authenticate and Proxy-Authenticate header field values because they
278     can contain more than one challenge, or if more than one of each is
279     provided, since the contents of a challenge can itself contain a
280     comma-separated list of authentication parameters.
281  </t>
282</x:note>
283<x:note>
284  <t>
285     <x:h>Note:</x:h> 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 401 (Unauthorized)
293   &mdash; can do so by including an Authorization 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 407 (Proxy Authentication Required)
299   &mdash; can do so by including a Proxy-Authorization header field with the
300   request.
301</t>
302<t>
303   Both the Authorization field value and the Proxy-Authorization 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   Requests for protected resources that omit credentials, contain invalid
316   credentials (e.g., a bad password), or partial credentials (e.g., when the
317   authentication scheme requires more than one round trip) &SHOULD; return a
318   401 (Unauthorized) response. Such responses &MUST; include a
319   WWW-Authenticate header field containing at least one (possibly new)
320   challenge applicable to the requested resource.
321</t>
322<t>
323   Likewise, requests that require authentication by proxies that omit
324   credentials, or contain invalid or partial credentials &SHOULD; return a
325   407 (Proxy Authentication Required) response. Such responses &MUST;
326   include a Proxy-Authenticate header field containing a (possibly new)
327   challenge applicable to the proxy.
328</t>
329<t>
330   A server receiving credentials that are valid, but not adequate to gain
331   access, ought to respond with the 403 (Forbidden) status code.
332</t>
333<t>
334   The HTTP protocol does not restrict applications to this simple
335   challenge-response mechanism for access authentication. Additional
336   mechanisms &MAY; be used, such as encryption at the transport level or
337   via message encapsulation, and with additional header fields
338   specifying authentication information. However, such additional
339   mechanisms are not defined by this specification.
340</t>
341<t>
342   Proxies &MUST; forward the WWW-Authenticate and Authorization headers
343   unmodified and follow the rules found in <xref target="header.authorization"/>.
344</t>
345</section>
346
347<section title="Protection Space (Realm)" anchor="protection.space">
348  <iref item="Protection Space"/>
349  <iref item="Realm"/>
350  <iref item="Canonical Root URI"/>
351<t>
352   The authentication parameter realm is reserved for use by authentication
353   schemes that wish to indicate the scope of protection.
354</t>
355<t>
356   A <x:dfn>protection space</x:dfn> is defined by the canonical root URI (the
357   scheme and authority components of the effective request URI; see
358   <xref target="Part1" x:fmt="of" x:rel="#effective.request.uri"/>) of the
359   server being accessed, in combination with the realm value if present.
360   These realms allow the protected resources on a server to be
361   partitioned into a set of protection spaces, each with its own
362   authentication scheme and/or authorization database. The realm value
363   is a string, generally assigned by the origin server, which can have
364   additional semantics specific to the authentication scheme. Note that
365   there can be multiple challenges with the same auth-scheme but
366   different realms.
367</t>
368<t>
369   The protection space determines the domain over which credentials can
370   be automatically applied. If a prior request has been authorized, the
371   same credentials &MAY; be reused for all other requests within that
372   protection space for a period of time determined by the
373   authentication scheme, parameters, and/or user preference. Unless
374   otherwise defined by the authentication scheme, a single protection
375   space cannot extend outside the scope of its server.
376</t>
377<t>
378   For historical reasons, senders &MUST; only use the quoted-string syntax.
379   Recipients might have to support both token and quoted-string syntax for
380   maximum interoperability with existing clients that have been accepting both
381   notations for a long time.
382</t>
383</section>
384
385<section title="Authentication Scheme Registry" anchor="authentication.scheme.registry">
386<t>
387  The HTTP Authentication Scheme Registry defines the name space for the
388  authentication schemes in challenges and credentials.
389</t>
390<t>
391  Registrations &MUST; include the following fields:
392  <list style="symbols">
393    <t>Authentication Scheme Name</t>
394    <t>Pointer to specification text</t>
395    <t>Notes (optional)</t>
396  </list>
397</t>
398<t>
399  Values to be added to this name space require IETF Review
400  (see <xref target="RFC5226" x:fmt="," x:sec="4.1"/>).
401</t>
402<t>
403  The registry itself is maintained at <eref target="http://www.iana.org/assignments/http-authschemes"/>.
404</t>
405
406<section title="Considerations for New Authentication Schemes" anchor="considerations.for.new.authentication.schemes">
407<t>
408  There are certain aspects of the HTTP Authentication Framework that put
409  constraints on how new authentication schemes can work:
410</t>
411<t>
412  <list style="symbols">
413    <x:lt>
414    <t>
415      HTTP authentication is presumed to be stateless: all of the information
416      necessary to authenticate a request &MUST; be provided in the request,
417      rather than be dependent on the server remembering prior requests.
418      Authentication based on, or bound to, the underlying connection is
419      outside the scope of this specification and inherently flawed unless
420      steps are taken to ensure that the connection cannot be used by any
421      party other than the authenticated user
422      (see &msg-orient-and-buffering;).
423    </t>
424    </x:lt>
425    <x:lt>
426    <t>
427      The authentication parameter "realm" is reserved for defining Protection
428      Spaces as defined in <xref target="protection.space"/>. New schemes
429      &MUST-NOT; use it in a way incompatible with that definition.
430    </t>
431    </x:lt>
432    <x:lt>
433    <t>
434      The "b64token" notation was introduced for compatibility with existing
435      authentication schemes and can only be used once per challenge/credentials.
436      New schemes thus ought to use the "auth-param" syntax instead, because
437      otherwise future extensions will be impossible.
438    </t>
439    </x:lt>
440    <x:lt>
441    <t>
442      The parsing of challenges and credentials is defined by this specification,
443      and cannot be modified by new authentication schemes. When the auth-param
444      syntax is used, all parameters ought to support both token and
445      quoted-string syntax, and syntactical constraints ought to be defined on
446      the field value after parsing (i.e., quoted-string processing). This is
447      necessary so that recipients can use a generic parser that applies to
448      all authentication schemes.
449    </t>
450    <t>
451      <x:h>Note:</x:h> the fact that the value syntax for the "realm" parameter
452      is restricted to quoted-string was a bad design choice not to be repeated
453      for new parameters.
454    </t>
455    </x:lt>
456    <x:lt>
457    <t>
458      Definitions of new schemes ought to define the treatment of unknown
459      extension parameters. In general, a "must-ignore" rule is preferable
460      over "must-understand", because otherwise it will be hard to introduce
461      new parameters in the presence of legacy recipients. Furthermore,
462      it's good to describe the policy for defining new parameters (such
463      as "update the specification", or "use this registry").
464    </t>
465    </x:lt>
466    <x:lt>
467    <t>
468      Authentication schemes need to document whether they are usable in
469      origin-server authentication (i.e., using WWW-Authenticate), and/or
470      proxy authentication (i.e., using Proxy-Authenticate).
471    </t>
472    </x:lt>
473    <x:lt>
474    <t>
475      The credentials carried in an Authorization header field are specific to
476      the User Agent, and therefore have the same effect on HTTP caches as the
477      "private" Cache-Control response directive, within the scope of the
478      request they appear in.
479    </t>
480    <t>
481      Therefore, new authentication schemes which choose not to carry
482      credentials in the Authorization header (e.g., using a newly defined
483      header) will need to explicitly disallow caching, by mandating the use of
484      either Cache-Control request directives (e.g., "no-store") or response
485      directives (e.g., "private").
486    </t>
487    </x:lt>
488  </list>
489</t>
490</section>
491
492</section>
493
494</section>
495
496<section title="Status Code Definitions" anchor="status.code.definitions">
497<section title="401 Unauthorized" anchor="status.401">
498  <iref primary="true" item="401 Unauthorized (status code)" x:for-anchor=""/>
499  <iref primary="true" item="Status Codes" subitem="401 Unauthorized" x:for-anchor=""/>
500<t>
501   The request requires user authentication. The response &MUST; include a
502   WWW-Authenticate header field (<xref target="header.www-authenticate"/>) containing a challenge
503   applicable to the target resource. The client &MAY; repeat the
504   request with a suitable Authorization header field (<xref target="header.authorization"/>). If
505   the request already included Authorization credentials, then the 401
506   response indicates that authorization has been refused for those
507   credentials. If the 401 response contains the same challenge as the
508   prior response, and the user agent has already attempted
509   authentication at least once, then the user &SHOULD; be presented the
510   representation that was given in the response, since that representation might
511   include relevant diagnostic information.
512</t>
513</section>
514<section title="407 Proxy Authentication Required" anchor="status.407">
515  <iref primary="true" item="407 Proxy Authentication Required (status code)" x:for-anchor=""/>
516  <iref primary="true" item="Status Codes" subitem="407 Proxy Authentication Required" x:for-anchor=""/>
517<t>
518   This code is similar to 401 (Unauthorized), but indicates that the
519   client ought to first authenticate itself with the proxy. The proxy &MUST;
520   return a Proxy-Authenticate header field (<xref target="header.proxy-authenticate"/>) containing a
521   challenge applicable to the proxy for the target resource. The
522   client &MAY; repeat the request with a suitable Proxy-Authorization
523   header field (<xref target="header.proxy-authorization"/>).
524</t>
525</section>
526</section>
527
528<section title="Header Field Definitions" anchor="header.field.definitions">
529<t>
530   This section defines the syntax and semantics of HTTP/1.1 header fields
531   related to authentication.
532</t>
533
534<section title="Authorization" anchor="header.authorization">
535  <iref primary="true" item="Authorization header field" x:for-anchor=""/>
536  <iref primary="true" item="Header Fields" subitem="Authorization" x:for-anchor=""/>
537  <x:anchor-alias value="Authorization"/>
538<t>
539   The "Authorization" header field allows a user agent to authenticate
540   itself with a server &mdash; usually, but not necessarily, after receiving a 401
541   (Unauthorized) response. Its value consists of credentials containing
542   information of the user agent for the realm of the resource being
543   requested.
544</t>
545<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Authorization"/>
546  <x:ref>Authorization</x:ref> = <x:ref>credentials</x:ref>
547</artwork></figure>
548<t>
549   If a request is
550   authenticated and a realm specified, the same credentials &SHOULD;
551   be valid for all other requests within this realm (assuming that
552   the authentication scheme itself does not require otherwise, such
553   as credentials that vary according to a challenge value or using
554   synchronized clocks).
555</t>
556<t>
557      When a shared cache (see &shared-and-non-shared-caches;) receives a request
558      containing an Authorization field, it &MUST-NOT; return the
559      corresponding response as a reply to any other request, unless one
560      of the following specific exceptions holds:
561</t>
562<t>
563  <list style="numbers">
564      <t>If the response includes the "s-maxage" cache-control
565         directive, the cache &MAY; use that response in replying to a
566         subsequent request. But (if the specified maximum age has
567         passed) a proxy cache &MUST; first revalidate it with the origin
568         server, using the header fields from the new request to allow
569         the origin server to authenticate the new request. (This is the
570         defined behavior for s-maxage.) If the response includes "s-maxage=0",
571         the proxy &MUST; always revalidate it before re-using
572         it.</t>
573
574      <t>If the response includes the "must-revalidate" cache-control
575         directive, the cache &MAY; use that response in replying to a
576         subsequent request. But if the response is stale, all caches
577         &MUST; first revalidate it with the origin server, using the
578         header fields from the new request to allow the origin server
579         to authenticate the new request.</t>
580
581      <t>If the response includes the "public" cache-control directive,
582         it &MAY; be returned in reply to any subsequent request.</t>
583  </list>
584</t>
585</section>
586
587<section title="Proxy-Authenticate" anchor="header.proxy-authenticate">
588  <iref primary="true" item="Proxy-Authenticate header field" x:for-anchor=""/>
589  <iref primary="true" item="Header Fields" subitem="Proxy-Authenticate" x:for-anchor=""/>
590  <x:anchor-alias value="Proxy-Authenticate"/>
591<t>
592   The "Proxy-Authenticate" header field consists of at least one
593   challenge that indicates the authentication scheme(s) and parameters
594   applicable to the proxy for this effective request URI (&effective-request-uri;).
595   It &MUST; be included as part of a 407 (Proxy Authentication Required) response.
596</t>
597<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authenticate"/>
598  <x:ref>Proxy-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
599</artwork></figure>
600<t>
601   Unlike WWW-Authenticate, the Proxy-Authenticate header field applies only to
602   the current connection and &SHOULD-NOT;  be passed on to downstream
603   clients. However, an intermediate proxy might need to obtain its own
604   credentials by requesting them from the downstream client, which in
605   some circumstances will appear as if the proxy is forwarding the
606   Proxy-Authenticate header field.
607</t>
608<t>
609   Note that the parsing considerations for WWW-Authenticate apply to this
610   header field as well; see <xref target="header.www-authenticate"/> for
611   details.
612</t>
613</section>
614
615<section title="Proxy-Authorization" anchor="header.proxy-authorization">
616  <iref primary="true" item="Proxy-Authorization header field" x:for-anchor=""/>
617  <iref primary="true" item="Header Fields" subitem="Proxy-Authorization" x:for-anchor=""/>
618  <x:anchor-alias value="Proxy-Authorization"/>
619<t>
620   The "Proxy-Authorization" header field allows the client to
621   identify itself (or its user) to a proxy which requires
622   authentication. Its value consists of
623   credentials containing the authentication information of the user
624   agent for the proxy and/or realm of the resource being requested.
625</t>
626<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Proxy-Authorization"/>
627  <x:ref>Proxy-Authorization</x:ref> = <x:ref>credentials</x:ref>
628</artwork></figure>
629<t>
630   Unlike Authorization, the Proxy-Authorization header field applies only to
631   the next outbound proxy that demanded authentication using the Proxy-Authenticate
632   field. When multiple proxies are used in a chain, the
633   Proxy-Authorization header field is consumed by the first outbound
634   proxy that was expecting to receive credentials. A proxy &MAY; relay
635   the credentials from the client request to the next proxy if that is
636   the mechanism by which the proxies cooperatively authenticate a given
637   request.
638</t>
639</section>
640
641<section title="WWW-Authenticate" anchor="header.www-authenticate">
642  <iref primary="true" item="WWW-Authenticate header field" x:for-anchor=""/>
643  <iref primary="true" item="Header Fields" subitem="WWW-Authenticate" x:for-anchor=""/>
644  <x:anchor-alias value="WWW-Authenticate"/>
645<t>
646   The "WWW-Authenticate" header field consists of at least one
647   challenge that indicates the authentication scheme(s) and parameters
648   applicable to the effective request URI (&effective-request-uri;).
649</t>
650<t>   
651   It &MUST; be included in 401 (Unauthorized) response messages and &MAY; be
652   included in other response messages to indicate that supplying credentials
653   (or different credentials) might affect the response.
654</t>
655<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="WWW-Authenticate"/>
656  <x:ref>WWW-Authenticate</x:ref> = 1#<x:ref>challenge</x:ref>
657</artwork></figure>
658<t>
659   User agents are advised to take special care in parsing the WWW-Authenticate
660   field value as it might contain more than one challenge,
661   or if more than one WWW-Authenticate header field is provided, the
662   contents of a challenge itself can contain a comma-separated list of
663   authentication parameters.
664</t>
665<figure>
666  <preamble>For instance:</preamble>
667  <artwork type="example">
668  WWW-Authenticate: Newauth realm="apps", type=1,
669                    title="Login to \"apps\"", Basic realm="simple"
670</artwork>
671  <postamble>
672  This header field contains two challenges; one for the "Newauth" scheme
673  with a realm value of "apps", and two additional parameters "type" and
674  "title", and another one for the "Basic" scheme with a realm value of
675  "simple".
676</postamble></figure>
677<x:note>
678  <t>
679    <x:h>Note:</x:h> The challenge grammar production uses the list syntax as
680    well. Therefore, a sequence of comma, whitespace, and comma can be
681    considered both as applying to the preceding challenge, or to be an
682    empty entry in the list of challenges. In practice, this ambiguity
683    does not affect the semantics of the header field value and thus is
684    harmless.
685  </t>
686</x:note>
687</section>
688
689</section>
690
691<section title="IANA Considerations" anchor="IANA.considerations">
692
693<section title="Authenticaton Scheme Registry" anchor="authentication.scheme.registration">
694<t>
695  The registration procedure for HTTP Authentication Schemes is defined by
696  <xref target="authentication.scheme.registry"/> of this document.
697</t>
698<t>
699   The HTTP Method Authentication Scheme shall be created at <eref target="http://www.iana.org/assignments/http-authschemes"/>.
700</t>
701</section>
702
703<section title="Status Code Registration" anchor="status.code.registration">
704<t>
705   The HTTP Status Code Registry located at <eref target="http://www.iana.org/assignments/http-status-codes"/>
706   shall be updated with the registrations below:
707</t>
708<?BEGININC p7-auth.iana-status-codes ?>
709<!--AUTOGENERATED FROM extract-status-code-defs.xslt, do not edit manually-->
710<texttable align="left" suppress-title="true" anchor="iana.status.code.registration.table">
711   <ttcol>Value</ttcol>
712   <ttcol>Description</ttcol>
713   <ttcol>Reference</ttcol>
714   <c>401</c>
715   <c>Unauthorized</c>
716   <c>
717      <xref target="status.401"/>
718   </c>
719   <c>407</c>
720   <c>Proxy Authentication Required</c>
721   <c>
722      <xref target="status.407"/>
723   </c>
724</texttable>
725<!--(END)-->
726<?ENDINC p7-auth.iana-status-codes ?>
727</section>
728
729<section title="Header Field Registration" anchor="header.field.registration">
730<t>
731   The Message Header Field Registry located at <eref target="http://www.iana.org/assignments/message-headers/message-header-index.html"/> shall be updated
732   with the permanent registrations below (see <xref target="RFC3864"/>):
733</t>
734<?BEGININC p7-auth.iana-headers ?>
735<!--AUTOGENERATED FROM extract-header-defs.xslt, do not edit manually-->
736<texttable align="left" suppress-title="true" anchor="iana.header.registration.table">
737   <ttcol>Header Field Name</ttcol>
738   <ttcol>Protocol</ttcol>
739   <ttcol>Status</ttcol>
740   <ttcol>Reference</ttcol>
741
742   <c>Authorization</c>
743   <c>http</c>
744   <c>standard</c>
745   <c>
746      <xref target="header.authorization"/>
747   </c>
748   <c>Proxy-Authenticate</c>
749   <c>http</c>
750   <c>standard</c>
751   <c>
752      <xref target="header.proxy-authenticate"/>
753   </c>
754   <c>Proxy-Authorization</c>
755   <c>http</c>
756   <c>standard</c>
757   <c>
758      <xref target="header.proxy-authorization"/>
759   </c>
760   <c>WWW-Authenticate</c>
761   <c>http</c>
762   <c>standard</c>
763   <c>
764      <xref target="header.www-authenticate"/>
765   </c>
766</texttable>
767<!--(END)-->
768<?ENDINC p7-auth.iana-headers ?>
769<t>
770   The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
771</t>
772</section>
773</section>
774
775<section title="Security Considerations" anchor="security.considerations">
776<t>
777   This section is meant to inform application developers, information
778   providers, and users of the security limitations in HTTP/1.1 as
779   described by this document. The discussion does not include
780   definitive solutions to the problems revealed, though it does make
781   some suggestions for reducing security risks.
782</t>
783
784<section title="Authentication Credentials and Idle Clients" anchor="auth.credentials.and.idle.clients">
785<t>
786   Existing HTTP clients and user agents typically retain authentication
787   information indefinitely. HTTP/1.1 does not provide a method for a
788   server to direct clients to discard these cached credentials. This is
789   a significant defect that requires further extensions to HTTP.
790   Circumstances under which credential caching can interfere with the
791   application's security model include but are not limited to:
792  <list style="symbols">
793     <t>Clients which have been idle for an extended period following
794        which the server might wish to cause the client to reprompt the
795        user for credentials.</t>
796
797     <t>Applications which include a session termination indication
798        (such as a "logout" or "commit" button on a page) after which
799        the server side of the application "knows" that there is no
800        further reason for the client to retain the credentials.</t>
801  </list>
802</t>
803<t>
804   This is currently under separate study. There are a number of work-arounds
805   to parts of this problem, and we encourage the use of
806   password protection in screen savers, idle time-outs, and other
807   methods which mitigate the security problems inherent in this
808   problem. In particular, user agents which cache credentials are
809   encouraged to provide a readily accessible mechanism for discarding
810   cached credentials under user control.
811</t>
812</section>
813
814<section title="Protection Spaces" anchor="protection.spaces">
815<t>
816  Authentication schemes that solely rely on the "realm" mechanism for
817  establishing a protection space will expose credentials to all resources on a
818  server. Clients that have successfully made authenticated requests with a
819  resource can use the same authentication credentials for other resources on
820  the same server. This makes it possible for a different resource to harvest
821  authentication credentials for other resources.
822</t>
823<t>
824  This is of particular concern when a server hosts resources for multiple
825  parties under the same canonical root URI (<xref target="protection.spaces"/>).
826  Possible mitigation strategies include restricting direct access to
827  authentication credentials (i.e., not making the content of the
828  Authorization request header field available), and separating protection
829  spaces by using a different host name for each party.
830</t>
831</section>
832</section>
833
834<section title="Acknowledgments" anchor="acks">
835<t>
836  This specification takes over the definition of the HTTP Authentication
837  Framework, previously defined in <xref target="RFC2617" x:fmt="none">RFC 2617</xref>.
838  We thank John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D. Lawrence,
839  Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for their work
840  on that specification. See <xref target="RFC2617" x:fmt="of" x:sec="6"/>
841  for further acknowledgements. 
842</t>
843<t>
844  See &acks; for the Acknowledgments related to this document revision.
845</t>
846</section>
847</middle>
848
849<back>
850
851<references title="Normative References">
852
853<reference anchor="Part1">
854  <front>
855    <title abbrev="HTTP/1.1">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</title>
856    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
857      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
858      <address><email>fielding@gbiv.com</email></address>
859    </author>
860    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
861      <organization abbrev="W3C">World Wide Web Consortium</organization>
862      <address><email>ylafon@w3.org</email></address>
863    </author>
864    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
865      <organization abbrev="greenbytes">greenbytes GmbH</organization>
866      <address><email>julian.reschke@greenbytes.de</email></address>
867    </author>
868    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
869  </front>
870  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p1-messaging-&ID-VERSION;"/>
871  <x:source href="p1-messaging.xml" basename="p1-messaging"/>
872</reference>
873
874<reference anchor="Part6">
875  <front>
876    <title abbrev="HTTP/1.1">HTTP/1.1, part 6: Caching</title>
877    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
878      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
879      <address><email>fielding@gbiv.com</email></address>
880    </author>
881    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
882      <organization abbrev="W3C">World Wide Web Consortium</organization>
883      <address><email>ylafon@w3.org</email></address>
884    </author>
885    <author initials="M." surname="Nottingham" fullname="Mark Nottingham" role="editor">
886      <organization>Rackspace</organization>
887      <address><email>mnot@mnot.net</email></address>
888    </author>
889    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
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-p6-cache-&ID-VERSION;"/>
896  <x:source href="p6-cache.xml" basename="p6-cache"/>
897</reference>
898
899<reference anchor="RFC2119">
900  <front>
901    <title>Key words for use in RFCs to Indicate Requirement Levels</title>
902    <author initials="S." surname="Bradner" fullname="Scott Bradner">
903      <organization>Harvard University</organization>
904      <address><email>sob@harvard.edu</email></address>
905    </author>
906    <date month="March" year="1997"/>
907  </front>
908  <seriesInfo name="BCP" value="14"/>
909  <seriesInfo name="RFC" value="2119"/>
910</reference>
911
912<reference anchor="RFC5234">
913  <front>
914    <title abbrev="ABNF for Syntax Specifications">Augmented BNF for Syntax Specifications: ABNF</title>
915    <author initials="D." surname="Crocker" fullname="Dave Crocker" role="editor">
916      <organization>Brandenburg InternetWorking</organization>
917      <address>
918        <email>dcrocker@bbiw.net</email>
919      </address> 
920    </author>
921    <author initials="P." surname="Overell" fullname="Paul Overell">
922      <organization>THUS plc.</organization>
923      <address>
924        <email>paul.overell@thus.net</email>
925      </address>
926    </author>
927    <date month="January" year="2008"/>
928  </front>
929  <seriesInfo name="STD" value="68"/>
930  <seriesInfo name="RFC" value="5234"/>
931</reference>
932
933</references>
934
935<references title="Informative References">
936
937<reference anchor="RFC2616">
938  <front>
939    <title>Hypertext Transfer Protocol -- HTTP/1.1</title>
940    <author initials="R." surname="Fielding" fullname="R. Fielding">
941      <organization>University of California, Irvine</organization>
942      <address><email>fielding@ics.uci.edu</email></address>
943    </author>
944    <author initials="J." surname="Gettys" fullname="J. Gettys">
945      <organization>W3C</organization>
946      <address><email>jg@w3.org</email></address>
947    </author>
948    <author initials="J." surname="Mogul" fullname="J. Mogul">
949      <organization>Compaq Computer Corporation</organization>
950      <address><email>mogul@wrl.dec.com</email></address>
951    </author>
952    <author initials="H." surname="Frystyk" fullname="H. Frystyk">
953      <organization>MIT Laboratory for Computer Science</organization>
954      <address><email>frystyk@w3.org</email></address>
955    </author>
956    <author initials="L." surname="Masinter" fullname="L. Masinter">
957      <organization>Xerox Corporation</organization>
958      <address><email>masinter@parc.xerox.com</email></address>
959    </author>
960    <author initials="P." surname="Leach" fullname="P. Leach">
961      <organization>Microsoft Corporation</organization>
962      <address><email>paulle@microsoft.com</email></address>
963    </author>
964    <author initials="T." surname="Berners-Lee" fullname="T. Berners-Lee">
965      <organization>W3C</organization>
966      <address><email>timbl@w3.org</email></address>
967    </author>
968    <date month="June" year="1999"/>
969  </front>
970  <seriesInfo name="RFC" value="2616"/>
971</reference>
972
973<reference anchor="RFC2617">
974  <front>
975    <title abbrev="HTTP Authentication">HTTP Authentication: Basic and Digest Access Authentication</title>
976    <author initials="J." surname="Franks" fullname="John Franks">
977      <organization>Northwestern University, Department of Mathematics</organization>
978      <address><email>john@math.nwu.edu</email></address>
979    </author>
980    <author initials="P.M." surname="Hallam-Baker" fullname="Phillip M. Hallam-Baker">
981      <organization>Verisign Inc.</organization>
982      <address><email>pbaker@verisign.com</email></address>
983    </author>
984    <author initials="J.L." surname="Hostetler" fullname="Jeffery L. Hostetler">
985      <organization>AbiSource, Inc.</organization>
986      <address><email>jeff@AbiSource.com</email></address>
987    </author>
988    <author initials="S.D." surname="Lawrence" fullname="Scott D. Lawrence">
989      <organization>Agranat Systems, Inc.</organization>
990      <address><email>lawrence@agranat.com</email></address>
991    </author>
992    <author initials="P.J." surname="Leach" fullname="Paul J. Leach">
993      <organization>Microsoft Corporation</organization>
994      <address><email>paulle@microsoft.com</email></address>
995    </author>
996    <author initials="A." surname="Luotonen" fullname="Ari Luotonen">
997      <organization>Netscape Communications Corporation</organization>
998    </author>
999    <author initials="L." surname="Stewart" fullname="Lawrence C. Stewart">
1000      <organization>Open Market, Inc.</organization>
1001      <address><email>stewart@OpenMarket.com</email></address>
1002    </author>
1003    <date month="June" year="1999"/>
1004  </front>
1005  <seriesInfo name="RFC" value="2617"/>
1006</reference>
1007
1008<reference anchor='RFC3864'>
1009  <front>
1010    <title>Registration Procedures for Message Header Fields</title>
1011    <author initials='G.' surname='Klyne' fullname='G. Klyne'>
1012      <organization>Nine by Nine</organization>
1013      <address><email>GK-IETF@ninebynine.org</email></address>
1014    </author>
1015    <author initials='M.' surname='Nottingham' fullname='M. Nottingham'>
1016      <organization>BEA Systems</organization>
1017      <address><email>mnot@pobox.com</email></address>
1018    </author>
1019    <author initials='J.' surname='Mogul' fullname='J. Mogul'>
1020      <organization>HP Labs</organization>
1021      <address><email>JeffMogul@acm.org</email></address>
1022    </author>
1023    <date year='2004' month='September' />
1024  </front>
1025  <seriesInfo name='BCP' value='90' />
1026  <seriesInfo name='RFC' value='3864' />
1027</reference>
1028
1029<reference anchor="RFC3986">
1030 <front>
1031  <title abbrev='URI Generic Syntax'>Uniform Resource Identifier (URI): Generic Syntax</title>
1032  <author initials='T.' surname='Berners-Lee' fullname='Tim Berners-Lee'>
1033    <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1034    <address>
1035       <email>timbl@w3.org</email>
1036       <uri>http://www.w3.org/People/Berners-Lee/</uri>
1037    </address>
1038  </author>
1039  <author initials='R.' surname='Fielding' fullname='Roy T. Fielding'>
1040    <organization abbrev="Day Software">Day Software</organization>
1041    <address>
1042      <email>fielding@gbiv.com</email>
1043      <uri>http://roy.gbiv.com/</uri>
1044    </address>
1045  </author>
1046  <author initials='L.' surname='Masinter' fullname='Larry Masinter'>
1047    <organization abbrev="Adobe Systems">Adobe Systems Incorporated</organization>
1048    <address>
1049      <email>LMM@acm.org</email>
1050      <uri>http://larry.masinter.net/</uri>
1051    </address>
1052  </author>
1053  <date month='January' year='2005'></date>
1054 </front>
1055 <seriesInfo name="STD" value="66"/>
1056 <seriesInfo name="RFC" value="3986"/>
1057</reference>
1058
1059<reference anchor="RFC4648">
1060  <front>
1061    <title>The Base16, Base32, and Base64 Data Encodings</title>
1062    <author fullname="S. Josefsson" initials="S." surname="Josefsson"/>
1063    <date year="2006" month="October"/>
1064  </front>
1065  <seriesInfo value="4648" name="RFC"/>
1066</reference>
1067
1068<reference anchor='RFC5226'>
1069  <front>
1070    <title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
1071    <author initials='T.' surname='Narten' fullname='T. Narten'>
1072      <organization>IBM</organization>
1073      <address><email>narten@us.ibm.com</email></address>
1074    </author>
1075    <author initials='H.' surname='Alvestrand' fullname='H. Alvestrand'>
1076      <organization>Google</organization>
1077      <address><email>Harald@Alvestrand.no</email></address>
1078    </author>
1079    <date year='2008' month='May' />
1080  </front>
1081  <seriesInfo name='BCP' value='26' />
1082  <seriesInfo name='RFC' value='5226' />
1083</reference>
1084
1085</references>
1086
1087<section title="Changes from RFCs 2616 and 2617" anchor="changes.from.rfc.2616">
1088<t>
1089  The "realm" parameter isn't required anymore in general; consequently, the
1090  ABNF allows challenges without any auth parameters.
1091  (<xref target="access.authentication.framework"/>)
1092</t>
1093<t>
1094  The "b64token" alternative to auth-param lists has been added for consistency
1095  with legacy authentication schemes such as "Basic".
1096  (<xref target="access.authentication.framework"/>)
1097</t>
1098<t>
1099  Change ABNF productions for header fields to only define the field value.
1100  (<xref target="header.field.definitions"/>)
1101</t>
1102</section>
1103 
1104<?BEGININC p7-auth.abnf-appendix ?>
1105<section xmlns:x="http://purl.org/net/xml2rfc/ext" title="Collected ABNF" anchor="collected.abnf">
1106<figure>
1107<artwork type="abnf" name="p7-auth.parsed-abnf">
1108<x:ref>Authorization</x:ref> = credentials
1109
1110<x:ref>BWS</x:ref> = &lt;BWS, defined in [Part1], Section 3.2.1&gt;
1111
1112<x:ref>OWS</x:ref> = &lt;OWS, defined in [Part1], Section 3.2.1&gt;
1113
1114<x:ref>Proxy-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS
1115 challenge ] )
1116<x:ref>Proxy-Authorization</x:ref> = credentials
1117
1118<x:ref>WWW-Authenticate</x:ref> = *( "," OWS ) challenge *( OWS "," [ OWS challenge
1119 ] )
1120
1121<x:ref>auth-param</x:ref> = token BWS "=" BWS ( token / quoted-string )
1122<x:ref>auth-scheme</x:ref> = token
1123
1124<x:ref>b64token</x:ref> = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
1125 *"="
1126
1127<x:ref>challenge</x:ref> = auth-scheme [ 1*SP ( b64token / [ ( "," / auth-param ) *(
1128 OWS "," [ OWS auth-param ] ) ] ) ]
1129<x:ref>credentials</x:ref> = auth-scheme [ 1*SP ( b64token / [ ( "," / auth-param )
1130 *( OWS "," [ OWS auth-param ] ) ] ) ]
1131
1132<x:ref>quoted-string</x:ref> = &lt;quoted-string, defined in [Part1], Section 3.2.4&gt;
1133
1134<x:ref>token</x:ref> = &lt;token, defined in [Part1], Section 3.2.4&gt;
1135</artwork>
1136</figure>
1137<figure><preamble>ABNF diagnostics:</preamble><artwork type="inline">
1138; Authorization defined but not used
1139; Proxy-Authenticate defined but not used
1140; Proxy-Authorization defined but not used
1141; WWW-Authenticate defined but not used
1142</artwork></figure></section>
1143<?ENDINC p7-auth.abnf-appendix ?>
1144
1145<section title="Change Log (to be removed by RFC Editor before publication)"  anchor="change.log">
1146<t>
1147  Changes up to the first Working Group Last Call draft are summarized
1148  in <eref target="http://trac.tools.ietf.org/html/draft-ietf-httpbis-p7-auth-19#appendix-C"/>.
1149</t>
1150
1151<section title="Since draft-ietf-httpbis-p7-auth-19" anchor="changes.since.19">
1152<t>
1153  Closed issues:
1154  <list style="symbols">
1155    <t>
1156      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/348"/>:
1157      "Realms and scope"
1158    </t>
1159    <t>
1160      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/349"/>:
1161      "Strength"
1162    </t>
1163    <t>
1164      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/357"/>:
1165      "Authentication exchanges"
1166    </t>
1167    <t>
1168      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/361"/>:
1169      "ABNF requirements for recipients"
1170    </t>
1171  </list>
1172</t>
1173</section>
1174
1175</section>
1176
1177</back>
1178</rfc>
Note: See TracBrowser for help on using the repository browser.