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2 HTTPbis Working Group R. Fielding, Ed.
3 Internet-Draft Adobe
4 Obsoletes: 2616 (if approved) J. Reschke, Ed.
5 Updates: 2617 (if approved) greenbytes
6 Intended status: Standards Track November 17, 2013
7 Expires: May 21, 2014
9 Hypertext Transfer Protocol (HTTP/1.1): Authentication
10 draft-ietf-httpbis-p7-auth-25
12 Abstract
14 The Hypertext Transfer Protocol (HTTP) is an application-level
15 protocol for distributed, collaborative, hypermedia information
16 systems. This document defines the HTTP Authentication framework.
18 Editorial Note (To be removed by RFC Editor)
20 Discussion of this draft takes place on the HTTPBIS working group
21 mailing list (ietf-http-wg@w3.org), which is archived at
22 .
24 The current issues list is at
25 and related
26 documents (including fancy diffs) can be found at
27 .
29 The changes in this draft are summarized in Appendix D.1.
31 Status of This Memo
33 This Internet-Draft is submitted in full conformance with the
34 provisions of BCP 78 and BCP 79.
36 Internet-Drafts are working documents of the Internet Engineering
37 Task Force (IETF). Note that other groups may also distribute
38 working documents as Internet-Drafts. The list of current Internet-
39 Drafts is at http://datatracker.ietf.org/drafts/current/.
41 Internet-Drafts are draft documents valid for a maximum of six months
42 and may be updated, replaced, or obsoleted by other documents at any
43 time. It is inappropriate to use Internet-Drafts as reference
44 material or to cite them other than as "work in progress."
46 This Internet-Draft will expire on May 21, 2014.
48 Copyright Notice
49 Copyright (c) 2013 IETF Trust and the persons identified as the
50 document authors. All rights reserved.
52 This document is subject to BCP 78 and the IETF Trust's Legal
53 Provisions Relating to IETF Documents
54 (http://trustee.ietf.org/license-info) in effect on the date of
55 publication of this document. Please review these documents
56 carefully, as they describe your rights and restrictions with respect
57 to this document. Code Components extracted from this document must
58 include Simplified BSD License text as described in Section 4.e of
59 the Trust Legal Provisions and are provided without warranty as
60 described in the Simplified BSD License.
62 This document may contain material from IETF Documents or IETF
63 Contributions published or made publicly available before November
64 10, 2008. The person(s) controlling the copyright in some of this
65 material may not have granted the IETF Trust the right to allow
66 modifications of such material outside the IETF Standards Process.
67 Without obtaining an adequate license from the person(s) controlling
68 the copyright in such materials, this document may not be modified
69 outside the IETF Standards Process, and derivative works of it may
70 not be created outside the IETF Standards Process, except to format
71 it for publication as an RFC or to translate it into languages other
72 than English.
74 Table of Contents
76 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
77 1.1. Conformance and Error Handling . . . . . . . . . . . . . . 4
78 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 4
79 2. Access Authentication Framework . . . . . . . . . . . . . . . 4
80 2.1. Challenge and Response . . . . . . . . . . . . . . . . . . 4
81 2.2. Protection Space (Realm) . . . . . . . . . . . . . . . . . 6
82 3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 7
83 3.1. 401 Unauthorized . . . . . . . . . . . . . . . . . . . . . 7
84 3.2. 407 Proxy Authentication Required . . . . . . . . . . . . 7
85 4. Header Field Definitions . . . . . . . . . . . . . . . . . . . 7
86 4.1. Authorization . . . . . . . . . . . . . . . . . . . . . . 7
87 4.2. Proxy-Authenticate . . . . . . . . . . . . . . . . . . . . 8
88 4.3. Proxy-Authorization . . . . . . . . . . . . . . . . . . . 8
89 4.4. WWW-Authenticate . . . . . . . . . . . . . . . . . . . . . 9
90 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
91 5.1. Authentication Scheme Registry . . . . . . . . . . . . . . 10
92 5.1.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 10
93 5.1.2. Considerations for New Authentication Schemes . . . . 10
94 5.2. Status Code Registration . . . . . . . . . . . . . . . . . 11
95 5.3. Header Field Registration . . . . . . . . . . . . . . . . 12
96 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
97 6.1. Authentication Credentials and Idle Clients . . . . . . . 12
98 6.2. Protection Spaces . . . . . . . . . . . . . . . . . . . . 13
99 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
100 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
101 8.1. Normative References . . . . . . . . . . . . . . . . . . . 14
102 8.2. Informative References . . . . . . . . . . . . . . . . . . 14
103 Appendix A. Changes from RFCs 2616 and 2617 . . . . . . . . . . . 15
104 Appendix B. Imported ABNF . . . . . . . . . . . . . . . . . . . . 15
105 Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 15
106 Appendix D. Change Log (to be removed by RFC Editor before
107 publication) . . . . . . . . . . . . . . . . . . . . 16
108 D.1. Since draft-ietf-httpbis-p7-auth-24 . . . . . . . . . . . 16
109 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
111 1. Introduction
113 This document defines HTTP/1.1 access control and authentication. It
114 includes the relevant parts of RFC 2616 with only minor changes
115 ([RFC2616]), plus the general framework for HTTP authentication, as
116 previously defined in "HTTP Authentication: Basic and Digest Access
117 Authentication" ([RFC2617]).
119 HTTP provides several OPTIONAL challenge-response authentication
120 schemes that can be used by a server to challenge a client request
121 and by a client to provide authentication information. The "basic"
122 and "digest" authentication schemes continue to be specified in RFC
123 2617.
125 1.1. Conformance and Error Handling
127 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
128 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
129 document are to be interpreted as described in [RFC2119].
131 Conformance criteria and considerations regarding error handling are
132 defined in Section 2.5 of [Part1].
134 1.2. Syntax Notation
136 This specification uses the Augmented Backus-Naur Form (ABNF)
137 notation of [RFC5234] with the list rule extension defined in Section
138 7 of [Part1]. Appendix B describes rules imported from other
139 documents. Appendix C shows the collected ABNF with the list rule
140 expanded.
142 2. Access Authentication Framework
144 2.1. Challenge and Response
146 HTTP provides a simple challenge-response authentication framework
147 that can be used by a server to challenge a client request and by a
148 client to provide authentication information. It uses a case-
149 insensitive token as a means to identify the authentication scheme,
150 followed by additional information necessary for achieving
151 authentication via that scheme. The latter can either be a comma-
152 separated list of parameters or a single sequence of characters
153 capable of holding base64-encoded information.
155 Parameters are name-value pairs where the name is matched case-
156 insensitively, and each parameter name MUST only occur once per
157 challenge.
159 auth-scheme = token
161 auth-param = token BWS "=" BWS ( token / quoted-string )
163 token68 = 1*( ALPHA / DIGIT /
164 "-" / "." / "_" / "~" / "+" / "/" ) *"="
166 The "token68" syntax allows the 66 unreserved URI characters
167 ([RFC3986]), plus a few others, so that it can hold a base64,
168 base64url (URL and filename safe alphabet), base32, or base16 (hex)
169 encoding, with or without padding, but excluding whitespace
170 ([RFC4648]).
172 The 401 (Unauthorized) response message is used by an origin server
173 to challenge the authorization of a user agent. This response MUST
174 include a WWW-Authenticate header field containing at least one
175 challenge applicable to the requested resource.
177 The 407 (Proxy Authentication Required) response message is used by a
178 proxy to challenge the authorization of a client and MUST include a
179 Proxy-Authenticate header field containing at least one challenge
180 applicable to the proxy for the requested resource.
182 challenge = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
184 Note: Many clients fail to parse challenges containing unknown
185 schemes. A workaround for this problem is to list well-supported
186 schemes (such as "basic") first.
188 A user agent that wishes to authenticate itself with an origin server
189 -- usually, but not necessarily, after receiving a 401 (Unauthorized)
190 -- can do so by including an Authorization header field with the
191 request.
193 A client that wishes to authenticate itself with a proxy -- usually,
194 but not necessarily, after receiving a 407 (Proxy Authentication
195 Required) -- can do so by including a Proxy-Authorization header
196 field with the request.
198 Both the Authorization field value and the Proxy-Authorization field
199 value contain the client's credentials for the realm of the resource
200 being requested, based upon a challenge received in a response
201 (possibly at some point in the past). When creating their values,
202 the user agent ought to do so by selecting the challenge with what it
203 considers to be the most secure auth-scheme that it understands,
204 obtaining credentials from the user as appropriate.
206 credentials = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
208 Upon receipt of a request for a protected resource that omits
209 credentials, contains invalid credentials (e.g., a bad password) or
210 partial credentials (e.g., when the authentication scheme requires
211 more than one round trip), an origin server SHOULD send a 401
212 (Unauthorized) response that contains a WWW-Authenticate header field
213 with at least one (possibly new) challenge applicable to the
214 requested resource.
216 Likewise, upon receipt of a request that requires authentication by
217 proxies that omit credentials or contain invalid or partial
218 credentials, a proxy SHOULD send a 407 (Proxy Authentication
219 Required) response that contains a Proxy-Authenticate header field
220 with a (possibly new) challenge applicable to the proxy.
222 A server receiving credentials that are valid, but not adequate to
223 gain access, ought to respond with the 403 (Forbidden) status code
224 (Section 6.5.3 of [Part2]).
226 HTTP does not restrict applications to this simple challenge-response
227 framework for access authentication. Additional mechanisms can be
228 used, such as authentication at the transport level or via message
229 encapsulation, and with additional header fields specifying
230 authentication information. However, such additional mechanisms are
231 not defined by this specification.
233 A proxy MUST forward the WWW-Authenticate and Authorization header
234 fields unmodified and follow the rules found in Section 4.1.
236 2.2. Protection Space (Realm)
238 The authentication parameter realm is reserved for use by
239 authentication schemes that wish to indicate the scope of protection.
241 A protection space is defined by the canonical root URI (the scheme
242 and authority components of the effective request URI; see Section
243 5.5 of [Part1]) of the server being accessed, in combination with the
244 realm value if present. These realms allow the protected resources
245 on a server to be partitioned into a set of protection spaces, each
246 with its own authentication scheme and/or authorization database.
247 The realm value is a string, generally assigned by the origin server,
248 which can have additional semantics specific to the authentication
249 scheme. Note that a response can have multiple challenges with the
250 same auth-scheme but different realms.
252 The protection space determines the domain over which credentials can
253 be automatically applied. If a prior request has been authorized,
254 the user agent MAY reuse the same credentials for all other requests
255 within that protection space for a period of time determined by the
256 authentication scheme, parameters, and/or user preferences (such as a
257 configurable inactivity timeout). Unless specifically allowed by the
258 authentication scheme, a single protection space cannot extend
259 outside the scope of its server.
261 For historical reasons, a sender MUST only generate the quoted-string
262 syntax. Recipients might have to support both token and quoted-
263 string syntax for maximum interoperability with existing clients that
264 have been accepting both notations for a long time.
266 3. Status Code Definitions
268 3.1. 401 Unauthorized
270 The 401 (Unauthorized) status code indicates that the request has not
271 been applied because it lacks valid authentication credentials for
272 the target resource. The origin server MUST send a WWW-Authenticate
273 header field (Section 4.4) containing at least one challenge
274 applicable to the target resource. If the request included
275 authentication credentials, then the 401 response indicates that
276 authorization has been refused for those credentials. The user agent
277 MAY repeat the request with a new or replaced Authorization header
278 field (Section 4.1). If the 401 response contains the same challenge
279 as the prior response, and the user agent has already attempted
280 authentication at least once, then the user agent SHOULD present the
281 enclosed representation to the user, since it usually contains
282 relevant diagnostic information.
284 3.2. 407 Proxy Authentication Required
286 The 407 (Proxy Authentication Required) status code is similar to 401
287 (Unauthorized), but indicates that the client needs to authenticate
288 itself in order to use a proxy. The proxy MUST send a Proxy-
289 Authenticate header field (Section 4.2) containing a challenge
290 applicable to that proxy for the target resource. The client MAY
291 repeat the request with a new or replaced Proxy-Authorization header
292 field (Section 4.3).
294 4. Header Field Definitions
296 This section defines the syntax and semantics of HTTP/1.1 header
297 fields related to authentication.
299 4.1. Authorization
301 The "Authorization" header field allows a user agent to authenticate
302 itself with an origin server -- usually, but not necessarily, after
303 receiving a 401 (Unauthorized) response. Its value consists of
304 credentials containing the authentication information of the user
305 agent for the realm of the resource being requested.
307 Authorization = credentials
309 If a request is authenticated and a realm specified, the same
310 credentials are presumed to be valid for all other requests within
311 this realm (assuming that the authentication scheme itself does not
312 require otherwise, such as credentials that vary according to a
313 challenge value or using synchronized clocks).
315 See Section 3.2 of [Part6] for details of and requirements pertaining
316 to handling of the Authorization field by HTTP caches.
318 4.2. Proxy-Authenticate
320 The "Proxy-Authenticate" header field consists of at least one
321 challenge that indicates the authentication scheme(s) and parameters
322 applicable to the proxy for this effective request URI (Section 5.5
323 of [Part1]). It MUST be included as part of a 407 (Proxy
324 Authentication Required) response.
326 Proxy-Authenticate = 1#challenge
328 Unlike WWW-Authenticate, the Proxy-Authenticate header field applies
329 only to the next outbound client on the response chain that chose to
330 direct its request to the responding proxy. If that recipient is
331 also a proxy, it will generally consume the Proxy-Authenticate header
332 field (and generate an appropriate Proxy-Authorization in a
333 subsequent request) rather than forward the header field to its own
334 outbound clients. However, if a recipient proxy needs to obtain its
335 own credentials by requesting them from a further outbound client, it
336 will generate its own 407 response, which might have the appearance
337 of forwarding the Proxy-Authenticate header field if both proxies use
338 the same challenge set.
340 Note that the parsing considerations for WWW-Authenticate apply to
341 this header field as well; see Section 4.4 for details.
343 4.3. Proxy-Authorization
345 The "Proxy-Authorization" header field allows the client to identify
346 itself (or its user) to a proxy that requires authentication. Its
347 value consists of credentials containing the authentication
348 information of the client for the proxy and/or realm of the resource
349 being requested.
351 Proxy-Authorization = credentials
353 Unlike Authorization, the Proxy-Authorization header field applies
354 only to the next inbound proxy that demanded authentication using the
355 Proxy-Authenticate field. When multiple proxies are used in a chain,
356 the Proxy-Authorization header field is consumed by the first inbound
357 proxy that was expecting to receive credentials. A proxy MAY relay
358 the credentials from the client request to the next proxy if that is
359 the mechanism by which the proxies cooperatively authenticate a given
360 request.
362 4.4. WWW-Authenticate
364 The "WWW-Authenticate" header field consists of at least one
365 challenge that indicates the authentication scheme(s) and parameters
366 applicable to the effective request URI (Section 5.5 of [Part1]).
368 It MUST be included in 401 (Unauthorized) response messages and MAY
369 be included in other response messages to indicate that supplying
370 credentials (or different credentials) might affect the response.
372 WWW-Authenticate = 1#challenge
374 User agents are advised to take special care in parsing the field
375 value, as it might contain more than one challenge, and each
376 challenge can contain a comma-separated list of authentication
377 parameters. Furthermore, the header field itself can occur multiple
378 times.
380 For instance:
382 WWW-Authenticate: Newauth realm="apps", type=1,
383 title="Login to \"apps\"", Basic realm="simple"
385 This header field contains two challenges; one for the "Newauth"
386 scheme with a realm value of "apps", and two additional parameters
387 "type" and "title", and another one for the "Basic" scheme with a
388 realm value of "simple".
390 Note: The challenge grammar production uses the list syntax as
391 well. Therefore, a sequence of comma, whitespace, and comma can
392 be considered either as applying to the preceding challenge, or to
393 be an empty entry in the list of challenges. In practice, this
394 ambiguity does not affect the semantics of the header field value
395 and thus is harmless.
397 5. IANA Considerations
399 5.1. Authentication Scheme Registry
401 The HTTP Authentication Scheme Registry defines the name space for
402 the authentication schemes in challenges and credentials. It will be
403 created and maintained at (the suggested URI)
404 .
406 5.1.1. Procedure
408 Registrations MUST include the following fields:
410 o Authentication Scheme Name
412 o Pointer to specification text
414 o Notes (optional)
416 Values to be added to this name space require IETF Review (see
417 [RFC5226], Section 4.1).
419 5.1.2. Considerations for New Authentication Schemes
421 There are certain aspects of the HTTP Authentication Framework that
422 put constraints on how new authentication schemes can work:
424 o HTTP authentication is presumed to be stateless: all of the
425 information necessary to authenticate a request MUST be provided
426 in the request, rather than be dependent on the server remembering
427 prior requests. Authentication based on, or bound to, the
428 underlying connection is outside the scope of this specification
429 and inherently flawed unless steps are taken to ensure that the
430 connection cannot be used by any party other than the
431 authenticated user (see Section 2.3 of [Part1]).
433 o The authentication parameter "realm" is reserved for defining
434 Protection Spaces as defined in Section 2.2. New schemes MUST NOT
435 use it in a way incompatible with that definition.
437 o The "token68" notation was introduced for compatibility with
438 existing authentication schemes and can only be used once per
439 challenge or credential. New schemes thus ought to use the "auth-
440 param" syntax instead, because otherwise future extensions will be
441 impossible.
443 o The parsing of challenges and credentials is defined by this
444 specification, and cannot be modified by new authentication
445 schemes. When the auth-param syntax is used, all parameters ought
446 to support both token and quoted-string syntax, and syntactical
447 constraints ought to be defined on the field value after parsing
448 (i.e., quoted-string processing). This is necessary so that
449 recipients can use a generic parser that applies to all
450 authentication schemes.
452 Note: The fact that the value syntax for the "realm" parameter is
453 restricted to quoted-string was a bad design choice not to be
454 repeated for new parameters.
456 o Definitions of new schemes ought to define the treatment of
457 unknown extension parameters. In general, a "must-ignore" rule is
458 preferable over "must-understand", because otherwise it will be
459 hard to introduce new parameters in the presence of legacy
460 recipients. Furthermore, it's good to describe the policy for
461 defining new parameters (such as "update the specification", or
462 "use this registry").
464 o Authentication schemes need to document whether they are usable in
465 origin-server authentication (i.e., using WWW-Authenticate),
466 and/or proxy authentication (i.e., using Proxy-Authenticate).
468 o The credentials carried in an Authorization header field are
469 specific to the User Agent, and therefore have the same effect on
470 HTTP caches as the "private" Cache-Control response directive
471 (Section 5.2.2.6 of [Part6]), within the scope of the request they
472 appear in.
474 Therefore, new authentication schemes that choose not to carry
475 credentials in the Authorization header field (e.g., using a newly
476 defined header field) will need to explicitly disallow caching, by
477 mandating the use of either Cache-Control request directives
478 (e.g., "no-store", Section 5.2.1.5 of [Part6]) or response
479 directives (e.g., "private").
481 5.2. Status Code Registration
483 The HTTP Status Code Registry located at
484 shall be updated
485 with the registrations below:
487 +-------+-------------------------------+-------------+
488 | Value | Description | Reference |
489 +-------+-------------------------------+-------------+
490 | 401 | Unauthorized | Section 3.1 |
491 | 407 | Proxy Authentication Required | Section 3.2 |
492 +-------+-------------------------------+-------------+
494 5.3. Header Field Registration
496 HTTP header fields are registered within the Message Header Field
497 Registry maintained at .
500 This document defines the following HTTP header fields, so their
501 associated registry entries shall be updated according to the
502 permanent registrations below (see [BCP90]):
504 +---------------------+----------+----------+-------------+
505 | Header Field Name | Protocol | Status | Reference |
506 +---------------------+----------+----------+-------------+
507 | Authorization | http | standard | Section 4.1 |
508 | Proxy-Authenticate | http | standard | Section 4.2 |
509 | Proxy-Authorization | http | standard | Section 4.3 |
510 | WWW-Authenticate | http | standard | Section 4.4 |
511 +---------------------+----------+----------+-------------+
513 The change controller is: "IETF (iesg@ietf.org) - Internet
514 Engineering Task Force".
516 6. Security Considerations
518 This section is meant to inform developers, information providers,
519 and users of known security concerns specific to HTTP/1.1
520 authentication. More general security considerations are addressed
521 in HTTP messaging [Part1] and semantics [Part2].
523 6.1. Authentication Credentials and Idle Clients
525 Existing HTTP clients and user agents typically retain authentication
526 information indefinitely. HTTP does not provide a mechanism for the
527 origin server to direct clients to discard these cached credentials,
528 since the protocol has no awareness of how credentials are obtained
529 or managed by the user agent. The mechanisms for expiring or
530 revoking credentials can be specified as part of an authentication
531 scheme definition.
533 Circumstances under which credential caching can interfere with the
534 application's security model include but are not limited to:
536 o Clients that have been idle for an extended period, following
537 which the server might wish to cause the client to re-prompt the
538 user for credentials.
540 o Applications that include a session termination indication (such
541 as a "logout" or "commit" button on a page) after which the server
542 side of the application "knows" that there is no further reason
543 for the client to retain the credentials.
545 User agents that cache credentials are encouraged to provide a
546 readily accessible mechanism for discarding cached credentials under
547 user control.
549 6.2. Protection Spaces
551 Authentication schemes that solely rely on the "realm" mechanism for
552 establishing a protection space will expose credentials to all
553 resources on an origin server. Clients that have successfully made
554 authenticated requests with a resource can use the same
555 authentication credentials for other resources on the same origin
556 server. This makes it possible for a different resource to harvest
557 authentication credentials for other resources.
559 This is of particular concern when an origin server hosts resources
560 for multiple parties under the same canonical root URI (Section 2.2).
561 Possible mitigation strategies include restricting direct access to
562 authentication credentials (i.e., not making the content of the
563 Authorization request header field available), and separating
564 protection spaces by using a different host name (or port number) for
565 each party.
567 7. Acknowledgments
569 This specification takes over the definition of the HTTP
570 Authentication Framework, previously defined in RFC 2617. We thank
571 John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D.
572 Lawrence, Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for
573 their work on that specification. See Section 6 of [RFC2617] for
574 further acknowledgements.
576 See Section 10 of [Part1] for the Acknowledgments related to this
577 document revision.
579 8. References
580 8.1. Normative References
582 [Part1] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
583 Protocol (HTTP/1.1): Message Syntax and Routing",
584 draft-ietf-httpbis-p1-messaging-25 (work in progress),
585 November 2013.
587 [Part2] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
588 Protocol (HTTP/1.1): Semantics and Content",
589 draft-ietf-httpbis-p2-semantics-25 (work in progress),
590 November 2013.
592 [Part6] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
593 Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
594 draft-ietf-httpbis-p6-cache-25 (work in progress),
595 November 2013.
597 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
598 Requirement Levels", BCP 14, RFC 2119, March 1997.
600 [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
601 Specifications: ABNF", STD 68, RFC 5234, January 2008.
603 8.2. Informative References
605 [BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration
606 Procedures for Message Header Fields", BCP 90, RFC 3864,
607 September 2004.
609 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
610 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
611 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
613 [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
614 Leach, P., Luotonen, A., and L. Stewart, "HTTP
615 Authentication: Basic and Digest Access Authentication",
616 RFC 2617, June 1999.
618 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
619 Resource Identifier (URI): Generic Syntax", STD 66,
620 RFC 3986, January 2005.
622 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
623 Encodings", RFC 4648, October 2006.
625 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
626 IANA Considerations Section in RFCs", BCP 26, RFC 5226,
627 May 2008.
629 Appendix A. Changes from RFCs 2616 and 2617
631 The framework for HTTP Authentication is now defined by this
632 document, rather than RFC 2617.
634 The "realm" parameter is no longer always required on challenges;
635 consequently, the ABNF allows challenges without any auth parameters.
636 (Section 2)
638 The "token68" alternative to auth-param lists has been added for
639 consistency with legacy authentication schemes such as "Basic".
640 (Section 2)
642 This specification introduces the Authentication Scheme Registry,
643 along with considerations for new authentication schemes.
644 (Section 5.1)
646 Appendix B. Imported ABNF
648 The following core rules are included by reference, as defined in
649 Appendix B.1 of [RFC5234]: ALPHA (letters), CR (carriage return),
650 CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double
651 quote), HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any
652 8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII
653 character).
655 The rules below are defined in [Part1]:
657 BWS =
658 OWS =
659 quoted-string =
660 token =
662 Appendix C. Collected ABNF
664 In the collected ABNF below, list rules are expanded as per Section
665 1.2 of [Part1].
667 Authorization = credentials
669 BWS =
671 OWS =
673 Proxy-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS
674 challenge ] )
675 Proxy-Authorization = credentials
677 WWW-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS challenge
678 ] )
680 auth-param = token BWS "=" BWS ( token / quoted-string )
681 auth-scheme = token
683 challenge = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param ) *(
684 OWS "," [ OWS auth-param ] ) ] ) ]
685 credentials = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param )
686 *( OWS "," [ OWS auth-param ] ) ] ) ]
688 quoted-string =
690 token =
691 token68 = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
692 *"="
694 Appendix D. Change Log (to be removed by RFC Editor before publication)
696 Changes up to the IETF Last Call draft are summarized in .
699 D.1. Since draft-ietf-httpbis-p7-auth-24
701 Closed issues:
703 o : "SECDIR review
704 of draft-ietf-httpbis-p7-auth-24"
706 o : "APPSDIR
707 review of draft-ietf-httpbis-p7-auth-24"
709 o : "note about
710 WWW-A parsing potentially misleading"
712 Index
714 4
715 401 Unauthorized (status code) 7
716 407 Proxy Authentication Required (status code) 7
718 A
719 Authorization header field 7
721 C
722 Canonical Root URI 6
724 G
725 Grammar
726 auth-param 5
727 auth-scheme 5
728 Authorization 8
729 challenge 5
730 credentials 5
731 Proxy-Authenticate 8
732 Proxy-Authorization 8
733 token68 5
734 WWW-Authenticate 9
736 P
737 Protection Space 6
738 Proxy-Authenticate header field 8
739 Proxy-Authorization header field 8
741 R
742 Realm 6
744 W
745 WWW-Authenticate header field 9
747 Authors' Addresses
749 Roy T. Fielding (editor)
750 Adobe Systems Incorporated
751 345 Park Ave
752 San Jose, CA 95110
753 USA
755 EMail: fielding@gbiv.com
756 URI: http://roy.gbiv.com/
757 Julian F. Reschke (editor)
758 greenbytes GmbH
759 Hafenweg 16
760 Muenster, NW 48155
761 Germany
763 EMail: julian.reschke@greenbytes.de
764 URI: http://greenbytes.de/tech/webdav/