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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 September 25, 2013
7 Expires: March 29, 2014
9 Hypertext Transfer Protocol (HTTP/1.1): Authentication
10 draft-ietf-httpbis-p7-auth-24
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.5.
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 March 29, 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
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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 . . . . . . . . . . . . . . . . . . . . . . 8
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-19 . . . . . . . . . . . 16
109 D.2. Since draft-ietf-httpbis-p7-auth-20 . . . . . . . . . . . 17
110 D.3. Since draft-ietf-httpbis-p7-auth-21 . . . . . . . . . . . 17
111 D.4. Since draft-ietf-httpbis-p7-auth-22 . . . . . . . . . . . 17
112 D.5. Since draft-ietf-httpbis-p7-auth-23 . . . . . . . . . . . 17
113 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
115 1. Introduction
117 This document defines HTTP/1.1 access control and authentication. It
118 includes the relevant parts of RFC 2616 with only minor changes
119 ([RFC2616]), plus the general framework for HTTP authentication, as
120 previously defined in "HTTP Authentication: Basic and Digest Access
121 Authentication" ([RFC2617]).
123 HTTP provides several OPTIONAL challenge-response authentication
124 schemes that can be used by a server to challenge a client request
125 and by a client to provide authentication information. The "basic"
126 and "digest" authentication schemes continue to be specified in RFC
127 2617.
129 1.1. Conformance and Error Handling
131 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
132 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
133 document are to be interpreted as described in [RFC2119].
135 Conformance criteria and considerations regarding error handling are
136 defined in Section 2.5 of [Part1].
138 1.2. Syntax Notation
140 This specification uses the Augmented Backus-Naur Form (ABNF)
141 notation of [RFC5234] with the list rule extension defined in Section
142 7 of [Part1]. Appendix B describes rules imported from other
143 documents. Appendix C shows the collected ABNF with the list rule
144 expanded.
146 2. Access Authentication Framework
148 2.1. Challenge and Response
150 HTTP provides a simple challenge-response authentication framework
151 that can be used by a server to challenge a client request and by a
152 client to provide authentication information. It uses a case-
153 insensitive token as a means to identify the authentication scheme,
154 followed by additional information necessary for achieving
155 authentication via that scheme. The latter can either be a comma-
156 separated list of parameters or a single sequence of characters
157 capable of holding base64-encoded information.
159 Parameters are name-value pairs where the name is matched case-
160 insensitively, and each parameter name MUST only occur once per
161 challenge.
163 auth-scheme = token
165 auth-param = token BWS "=" BWS ( token / quoted-string )
167 token68 = 1*( ALPHA / DIGIT /
168 "-" / "." / "_" / "~" / "+" / "/" ) *"="
170 The "token68" syntax allows the 66 unreserved URI characters
171 ([RFC3986]), plus a few others, so that it can hold a base64,
172 base64url (URL and filename safe alphabet), base32, or base16 (hex)
173 encoding, with or without padding, but excluding whitespace
174 ([RFC4648]).
176 The 401 (Unauthorized) response message is used by an origin server
177 to challenge the authorization of a user agent. This response MUST
178 include a WWW-Authenticate header field containing at least one
179 challenge applicable to the requested resource.
181 The 407 (Proxy Authentication Required) response message is used by a
182 proxy to challenge the authorization of a client and MUST include a
183 Proxy-Authenticate header field containing at least one challenge
184 applicable to the proxy for the requested resource.
186 challenge = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
188 Note: User agents will need to take special care in parsing the
189 WWW-Authenticate and Proxy-Authenticate header field values
190 because they can contain more than one challenge, or if more than
191 one of each is provided, since the contents of a challenge can
192 itself contain a comma-separated list of authentication
193 parameters.
195 Note: Many clients fail to parse challenges containing unknown
196 schemes. A workaround for this problem is to list well-supported
197 schemes (such as "basic") first.
199 A user agent that wishes to authenticate itself with an origin server
200 -- usually, but not necessarily, after receiving a 401 (Unauthorized)
201 -- can do so by including an Authorization header field with the
202 request.
204 A client that wishes to authenticate itself with a proxy -- usually,
205 but not necessarily, after receiving a 407 (Proxy Authentication
206 Required) -- can do so by including a Proxy-Authorization header
207 field with the request.
209 Both the Authorization field value and the Proxy-Authorization field
210 value contain the client's credentials for the realm of the resource
211 being requested, based upon a challenge received in a response
212 (possibly at some point in the past). When creating their values,
213 the user agent ought to do so by selecting the challenge with what it
214 considers to be the most secure auth-scheme that it understands,
215 obtaining credentials from the user as appropriate.
217 credentials = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
219 Upon a request for a protected resource that omits credentials,
220 contains invalid credentials (e.g., a bad password) or partial
221 credentials (e.g., when the authentication scheme requires more than
222 one round trip), an origin server SHOULD send a 401 (Unauthorized)
223 response that contains a WWW-Authenticate header field with at least
224 one (possibly new) challenge applicable to the requested resource.
226 Likewise, upon a request that requires authentication by proxies that
227 omit credentials or contain invalid or partial credentials, a proxy
228 SHOULD send a 407 (Proxy Authentication Required) response that
229 contains a Proxy-Authenticate header field with a (possibly new)
230 challenge applicable to the proxy.
232 A server receiving credentials that are valid, but not adequate to
233 gain access, ought to respond with the 403 (Forbidden) status code
234 (Section 6.5.3 of [Part2]).
236 The HTTP protocol does not restrict applications to this simple
237 challenge-response framework for access authentication. Additional
238 mechanisms MAY be used, such as encryption at the transport level or
239 via message encapsulation, and with additional header fields
240 specifying authentication information. However, such additional
241 mechanisms are not defined by this specification.
243 A proxy MUST forward the WWW-Authenticate and Authorization header
244 fields unmodified and follow the rules found in Section 4.1.
246 2.2. Protection Space (Realm)
248 The authentication parameter realm is reserved for use by
249 authentication schemes that wish to indicate the scope of protection.
251 A protection space is defined by the canonical root URI (the scheme
252 and authority components of the effective request URI; see Section
253 5.5 of [Part1]) of the server being accessed, in combination with the
254 realm value if present. These realms allow the protected resources
255 on a server to be partitioned into a set of protection spaces, each
256 with its own authentication scheme and/or authorization database.
257 The realm value is a string, generally assigned by the origin server,
258 which can have additional semantics specific to the authentication
259 scheme. Note that a response can have multiple challenges with the
260 same auth-scheme but different realms.
262 The protection space determines the domain over which credentials can
263 be automatically applied. If a prior request has been authorized,
264 the user agent MAY reuse the same credentials for all other requests
265 within that protection space for a period of time determined by the
266 authentication scheme, parameters, and/or user preference. Unless
267 specifically allowed by the authentication scheme, a single
268 protection space cannot extend outside the scope of its server.
270 For historical reasons, a sender MUST only generate the quoted-string
271 syntax. Recipients might have to support both token and quoted-
272 string syntax for maximum interoperability with existing clients that
273 have been accepting both notations for a long time.
275 3. Status Code Definitions
277 3.1. 401 Unauthorized
279 The 401 (Unauthorized) status code indicates that the request has not
280 been applied because it lacks valid authentication credentials for
281 the target resource. The origin server MUST send a WWW-Authenticate
282 header field (Section 4.4) containing at least one challenge
283 applicable to the target resource. If the request included
284 authentication credentials, then the 401 response indicates that
285 authorization has been refused for those credentials. The user agent
286 MAY repeat the request with a new or replaced Authorization header
287 field (Section 4.1). If the 401 response contains the same challenge
288 as the prior response, and the user agent has already attempted
289 authentication at least once, then the user agent SHOULD present the
290 enclosed representation to the user, since it usually contains
291 relevant diagnostic information.
293 3.2. 407 Proxy Authentication Required
295 The 407 (Proxy Authentication Required) status code is similar to 401
296 (Unauthorized), but indicates that the client needs to authenticate
297 itself in order to use a proxy. The proxy MUST send a Proxy-
298 Authenticate header field (Section 4.2) containing a challenge
299 applicable to that proxy for the target resource. The client MAY
300 repeat the request with a new or replaced Proxy-Authorization header
301 field (Section 4.3).
303 4. Header Field Definitions
305 This section defines the syntax and semantics of HTTP/1.1 header
306 fields related to authentication.
308 4.1. Authorization
310 The "Authorization" header field allows a user agent to authenticate
311 itself with an origin server -- usually, but not necessarily, after
312 receiving a 401 (Unauthorized) response. Its value consists of
313 credentials containing the authentication information of the user
314 agent for the realm of the resource being requested.
316 Authorization = credentials
318 If a request is authenticated and a realm specified, the same
319 credentials are presumed to be valid for all other requests within
320 this realm (assuming that the authentication scheme itself does not
321 require otherwise, such as credentials that vary according to a
322 challenge value or using synchronized clocks).
324 See Section 3.2 of [Part6] for details of and requirements pertaining
325 to handling of the Authorization field by HTTP caches.
327 4.2. Proxy-Authenticate
329 The "Proxy-Authenticate" header field consists of at least one
330 challenge that indicates the authentication scheme(s) and parameters
331 applicable to the proxy for this effective request URI (Section 5.5
332 of [Part1]). It MUST be included as part of a 407 (Proxy
333 Authentication Required) response.
335 Proxy-Authenticate = 1#challenge
337 Unlike WWW-Authenticate, the Proxy-Authenticate header field applies
338 only to the next outbound client on the response chain that chose to
339 direct its request to the responding proxy. If that recipient is
340 also a proxy, it will generally consume the Proxy-Authenticate header
341 field (and generate an appropriate Proxy-Authorization in a
342 subsequent request) rather than forward the header field to its own
343 outbound clients. However, if a recipient proxy needs to obtain its
344 own credentials by requesting them from a further outbound client, it
345 will generate its own 407 response, which might have the appearance
346 of forwarding the Proxy-Authenticate header field if both proxies use
347 the same challenge set.
349 Note that the parsing considerations for WWW-Authenticate apply to
350 this header field as well; see Section 4.4 for details.
352 4.3. Proxy-Authorization
354 The "Proxy-Authorization" header field allows the client to identify
355 itself (or its user) to a proxy that requires authentication. Its
356 value consists of credentials containing the authentication
357 information of the client for the proxy and/or realm of the resource
358 being requested.
360 Proxy-Authorization = credentials
362 Unlike Authorization, the Proxy-Authorization header field applies
363 only to the next inbound proxy that demanded authentication using the
364 Proxy-Authenticate field. When multiple proxies are used in a chain,
365 the Proxy-Authorization header field is consumed by the first inbound
366 proxy that was expecting to receive credentials. A proxy MAY relay
367 the credentials from the client request to the next proxy if that is
368 the mechanism by which the proxies cooperatively authenticate a given
369 request.
371 4.4. WWW-Authenticate
373 The "WWW-Authenticate" header field consists of at least one
374 challenge that indicates the authentication scheme(s) and parameters
375 applicable to the effective request URI (Section 5.5 of [Part1]).
377 It MUST be included in 401 (Unauthorized) response messages and MAY
378 be included in other response messages to indicate that supplying
379 credentials (or different credentials) might affect the response.
381 WWW-Authenticate = 1#challenge
383 User agents are advised to take special care in parsing the WWW-
384 Authenticate field value as it might contain more than one challenge,
385 or if more than one WWW-Authenticate header field is provided, the
386 contents of a challenge itself can contain a comma-separated list of
387 authentication parameters.
389 For instance:
391 WWW-Authenticate: Newauth realm="apps", type=1,
392 title="Login to \"apps\"", Basic realm="simple"
394 This header field contains two challenges; one for the "Newauth"
395 scheme with a realm value of "apps", and two additional parameters
396 "type" and "title", and another one for the "Basic" scheme with a
397 realm value of "simple".
399 Note: The challenge grammar production uses the list syntax as
400 well. Therefore, a sequence of comma, whitespace, and comma can
401 be considered both as applying to the preceding challenge, or to
402 be an empty entry in the list of challenges. In practice, this
403 ambiguity does not affect the semantics of the header field value
404 and thus is harmless.
406 5. IANA Considerations
408 5.1. Authentication Scheme Registry
410 The HTTP Authentication Scheme Registry defines the name space for
411 the authentication schemes in challenges and credentials. It will be
412 created and maintained at
413 .
415 5.1.1. Procedure
417 Registrations MUST include the following fields:
419 o Authentication Scheme Name
421 o Pointer to specification text
423 o Notes (optional)
425 Values to be added to this name space require IETF Review (see
426 [RFC5226], Section 4.1).
428 5.1.2. Considerations for New Authentication Schemes
430 There are certain aspects of the HTTP Authentication Framework that
431 put constraints on how new authentication schemes can work:
433 o HTTP authentication is presumed to be stateless: all of the
434 information necessary to authenticate a request MUST be provided
435 in the request, rather than be dependent on the server remembering
436 prior requests. Authentication based on, or bound to, the
437 underlying connection is outside the scope of this specification
438 and inherently flawed unless steps are taken to ensure that the
439 connection cannot be used by any party other than the
440 authenticated user (see Section 2.3 of [Part1]).
442 o The authentication parameter "realm" is reserved for defining
443 Protection Spaces as defined in Section 2.2. New schemes MUST NOT
444 use it in a way incompatible with that definition.
446 o The "token68" notation was introduced for compatibility with
447 existing authentication schemes and can only be used once per
448 challenge or credential. New schemes thus ought to use the "auth-
449 param" syntax instead, because otherwise future extensions will be
450 impossible.
452 o The parsing of challenges and credentials is defined by this
453 specification, and cannot be modified by new authentication
454 schemes. When the auth-param syntax is used, all parameters ought
455 to support both token and quoted-string syntax, and syntactical
456 constraints ought to be defined on the field value after parsing
457 (i.e., quoted-string processing). This is necessary so that
458 recipients can use a generic parser that applies to all
459 authentication schemes.
461 Note: The fact that the value syntax for the "realm" parameter is
462 restricted to quoted-string was a bad design choice not to be
463 repeated for new parameters.
465 o Definitions of new schemes ought to define the treatment of
466 unknown extension parameters. In general, a "must-ignore" rule is
467 preferable over "must-understand", because otherwise it will be
468 hard to introduce new parameters in the presence of legacy
469 recipients. Furthermore, it's good to describe the policy for
470 defining new parameters (such as "update the specification", or
471 "use this registry").
473 o Authentication schemes need to document whether they are usable in
474 origin-server authentication (i.e., using WWW-Authenticate),
475 and/or proxy authentication (i.e., using Proxy-Authenticate).
477 o The credentials carried in an Authorization header field are
478 specific to the User Agent, and therefore have the same effect on
479 HTTP caches as the "private" Cache-Control response directive
480 (Section 5.2.2.6 of [Part6]), within the scope of the request they
481 appear in.
483 Therefore, new authentication schemes that choose not to carry
484 credentials in the Authorization header field (e.g., using a newly
485 defined header field) will need to explicitly disallow caching, by
486 mandating the use of either Cache-Control request directives
487 (e.g., "no-store", Section 5.2.1.5 of [Part6]) or response
488 directives (e.g., "private").
490 5.2. Status Code Registration
492 The HTTP Status Code Registry located at
493 shall be updated
494 with the registrations below:
496 +-------+-------------------------------+-------------+
497 | Value | Description | Reference |
498 +-------+-------------------------------+-------------+
499 | 401 | Unauthorized | Section 3.1 |
500 | 407 | Proxy Authentication Required | Section 3.2 |
501 +-------+-------------------------------+-------------+
503 5.3. Header Field Registration
505 HTTP header fields are registered within the Message Header Field
506 Registry maintained at .
509 This document defines the following HTTP header fields, so their
510 associated registry entries shall be updated according to the
511 permanent registrations below (see [BCP90]):
513 +---------------------+----------+----------+-------------+
514 | Header Field Name | Protocol | Status | Reference |
515 +---------------------+----------+----------+-------------+
516 | Authorization | http | standard | Section 4.1 |
517 | Proxy-Authenticate | http | standard | Section 4.2 |
518 | Proxy-Authorization | http | standard | Section 4.3 |
519 | WWW-Authenticate | http | standard | Section 4.4 |
520 +---------------------+----------+----------+-------------+
522 The change controller is: "IETF (iesg@ietf.org) - Internet
523 Engineering Task Force".
525 6. Security Considerations
527 This section is meant to inform developers, information providers,
528 and users of known security concerns specific to HTTP/1.1
529 authentication. More general security considerations are addressed
530 in HTTP messaging [Part1] and semantics [Part2].
532 6.1. Authentication Credentials and Idle Clients
534 Existing HTTP clients and user agents typically retain authentication
535 information indefinitely. HTTP does not provide a mechanism for the
536 origin server to direct clients to discard these cached credentials,
537 since the protocol has no awareness of how credentials are obtained
538 or managed by the user agent. The mechanisms for expiring or
539 revoking credentials can be specified as part of an authentication
540 scheme definition.
542 Circumstances under which credential caching can interfere with the
543 application's security model include but are not limited to:
545 o Clients that have been idle for an extended period, following
546 which the server might wish to cause the client to re-prompt the
547 user for credentials.
549 o Applications that include a session termination indication (such
550 as a "logout" or "commit" button on a page) after which the server
551 side of the application "knows" that there is no further reason
552 for the client to retain the credentials.
554 User agents that cache credentials are encouraged to provide a
555 readily accessible mechanism for discarding cached credentials under
556 user control.
558 6.2. Protection Spaces
560 Authentication schemes that solely rely on the "realm" mechanism for
561 establishing a protection space will expose credentials to all
562 resources on an origin server. Clients that have successfully made
563 authenticated requests with a resource can use the same
564 authentication credentials for other resources on the same origin
565 server. This makes it possible for a different resource to harvest
566 authentication credentials for other resources.
568 This is of particular concern when an origin server hosts resources
569 for multiple parties under the same canonical root URI (Section 2.2).
570 Possible mitigation strategies include restricting direct access to
571 authentication credentials (i.e., not making the content of the
572 Authorization request header field available), and separating
573 protection spaces by using a different host name (or port number) for
574 each party.
576 7. Acknowledgments
578 This specification takes over the definition of the HTTP
579 Authentication Framework, previously defined in RFC 2617. We thank
580 John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D.
581 Lawrence, Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for
582 their work on that specification. See Section 6 of [RFC2617] for
583 further acknowledgements.
585 See Section 10 of [Part1] for the Acknowledgments related to this
586 document revision.
588 8. References
589 8.1. Normative References
591 [Part1] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
592 Protocol (HTTP/1.1): Message Syntax and Routing",
593 draft-ietf-httpbis-p1-messaging-24 (work in progress),
594 September 2013.
596 [Part2] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
597 Protocol (HTTP/1.1): Semantics and Content",
598 draft-ietf-httpbis-p2-semantics-24 (work in progress),
599 September 2013.
601 [Part6] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
602 Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
603 draft-ietf-httpbis-p6-cache-24 (work in progress),
604 September 2013.
606 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
607 Requirement Levels", BCP 14, RFC 2119, March 1997.
609 [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
610 Specifications: ABNF", STD 68, RFC 5234, January 2008.
612 8.2. Informative References
614 [BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration
615 Procedures for Message Header Fields", BCP 90, RFC 3864,
616 September 2004.
618 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
619 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
620 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
622 [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
623 Leach, P., Luotonen, A., and L. Stewart, "HTTP
624 Authentication: Basic and Digest Access Authentication",
625 RFC 2617, June 1999.
627 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
628 Resource Identifier (URI): Generic Syntax", STD 66,
629 RFC 3986, January 2005.
631 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
632 Encodings", RFC 4648, October 2006.
634 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
635 IANA Considerations Section in RFCs", BCP 26, RFC 5226,
636 May 2008.
638 Appendix A. Changes from RFCs 2616 and 2617
640 The framework for HTTP Authentication is now defined by this
641 document, rather than RFC 2617.
643 The "realm" parameter is no longer always required on challenges;
644 consequently, the ABNF allows challenges without any auth parameters.
645 (Section 2)
647 The "token68" alternative to auth-param lists has been added for
648 consistency with legacy authentication schemes such as "Basic".
649 (Section 2)
651 This specification introduces the Authentication Scheme Registry,
652 along with considerations for new authentication schemes.
653 (Section 5.1)
655 Appendix B. Imported ABNF
657 The following core rules are included by reference, as defined in
658 Appendix B.1 of [RFC5234]: ALPHA (letters), CR (carriage return),
659 CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double
660 quote), HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any
661 8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII
662 character).
664 The rules below are defined in [Part1]:
666 BWS =
667 OWS =
668 quoted-string =
669 token =
671 Appendix C. Collected ABNF
673 In the collected ABNF below, list rules are expanded as per Section
674 1.2 of [Part1].
676 Authorization = credentials
678 BWS =
680 OWS =
682 Proxy-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS
683 challenge ] )
684 Proxy-Authorization = credentials
686 WWW-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS challenge
687 ] )
689 auth-param = token BWS "=" BWS ( token / quoted-string )
690 auth-scheme = token
692 challenge = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param ) *(
693 OWS "," [ OWS auth-param ] ) ] ) ]
694 credentials = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param )
695 *( OWS "," [ OWS auth-param ] ) ] ) ]
697 quoted-string =
699 token =
700 token68 = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
701 *"="
703 Appendix D. Change Log (to be removed by RFC Editor before publication)
705 Changes up to the first Working Group Last Call draft are summarized
706 in .
709 D.1. Since draft-ietf-httpbis-p7-auth-19
711 Closed issues:
713 o : "Realms and
714 scope"
716 o : "Strength"
718 o :
719 "Authentication exchanges"
721 o : "ABNF
722 requirements for recipients"
724 o : "note
725 introduction of new IANA registries as normative changes"
727 D.2. Since draft-ietf-httpbis-p7-auth-20
729 Closed issues:
731 o : "rename
732 b64token for clarity"
734 Other changes:
736 o Conformance criteria and considerations regarding error handling
737 are now defined in Part 1.
739 D.3. Since draft-ietf-httpbis-p7-auth-21
741 Closed issues:
743 o :
744 "Authentication and caching - max-age"
746 D.4. Since draft-ietf-httpbis-p7-auth-22
748 Closed issues:
750 o : "explain list
751 expansion in ABNF appendices"
753 o : "terminology:
754 mechanism vs framework vs scheme"
756 o : "Editorial
757 suggestions"
759 o : "placement of
760 extension point considerations"
762 D.5. Since draft-ietf-httpbis-p7-auth-23
764 Closed issues:
766 o : "Forwarding
767 Proxy-*"
769 Index
771 4
772 401 Unauthorized (status code) 7
773 407 Proxy Authentication Required (status code) 7
775 A
776 Authorization header field 8
778 C
779 Canonical Root URI 6
781 G
782 Grammar
783 auth-param 5
784 auth-scheme 5
785 Authorization 8
786 challenge 5
787 credentials 6
788 Proxy-Authenticate 8
789 Proxy-Authorization 9
790 token68 5
791 WWW-Authenticate 9
793 P
794 Protection Space 6
795 Proxy-Authenticate header field 8
796 Proxy-Authorization header field 8
798 R
799 Realm 6
801 W
802 WWW-Authenticate header field 9
804 Authors' Addresses
806 Roy T. Fielding (editor)
807 Adobe Systems Incorporated
808 345 Park Ave
809 San Jose, CA 95110
810 USA
812 EMail: fielding@gbiv.com
813 URI: http://roy.gbiv.com/
814 Julian F. Reschke (editor)
815 greenbytes GmbH
816 Hafenweg 16
817 Muenster, NW 48155
818 Germany
820 EMail: julian.reschke@greenbytes.de
821 URI: http://greenbytes.de/tech/webdav/