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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 February 23, 2013
7 Expires: August 27, 2013
9 Hypertext Transfer Protocol (HTTP/1.1): Authentication
10 draft-ietf-httpbis-p7-auth-22
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.3.
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 August 27, 2013.
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
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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
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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 2.3. Authentication Scheme Registry . . . . . . . . . . . . . . 7
83 2.3.1. Considerations for New Authentication Schemes . . . . 7
84 3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 9
85 3.1. 401 Unauthorized . . . . . . . . . . . . . . . . . . . . . 9
86 3.2. 407 Proxy Authentication Required . . . . . . . . . . . . 9
87 4. Header Field Definitions . . . . . . . . . . . . . . . . . . . 9
88 4.1. Authorization . . . . . . . . . . . . . . . . . . . . . . 9
89 4.2. Proxy-Authenticate . . . . . . . . . . . . . . . . . . . . 10
90 4.3. Proxy-Authorization . . . . . . . . . . . . . . . . . . . 10
91 4.4. WWW-Authenticate . . . . . . . . . . . . . . . . . . . . . 10
92 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
93 5.1. Authentication Scheme Registry . . . . . . . . . . . . . . 11
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 . . . . . . . . . . . . . . . . . . . . . . . . . . 13
101 8.1. Normative References . . . . . . . . . . . . . . . . . . . 13
102 8.2. Informative References . . . . . . . . . . . . . . . . . . 14
103 Appendix A. Changes from RFCs 2616 and 2617 . . . . . . . . . . . 14
104 Appendix B. Imported ABNF . . . . . . . . . . . . . . . . . . . . 15
105 Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 16
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 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
113 1. Introduction
115 This document defines HTTP/1.1 access control and authentication. It
116 includes the relevant parts of RFC 2616 with only minor changes
117 ([RFC2616]), plus the general framework for HTTP authentication, as
118 previously defined in "HTTP Authentication: Basic and Digest Access
119 Authentication" ([RFC2617]).
121 HTTP provides several OPTIONAL challenge-response authentication
122 mechanisms that can be used by a server to challenge a client request
123 and by a client to provide authentication information. The "basic"
124 and "digest" authentication schemes continue to be specified in RFC
125 2617.
127 1.1. Conformance and Error Handling
129 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
130 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
131 document are to be interpreted as described in [RFC2119].
133 Conformance criteria and considerations regarding error handling are
134 defined in Section 2.5 of [Part1].
136 1.2. Syntax Notation
138 This specification uses the Augmented Backus-Naur Form (ABNF)
139 notation of [RFC5234] with the list rule extension defined in Section
140 1.2 of [Part1]. Appendix B describes rules imported from other
141 documents. Appendix C shows the collected ABNF with the list rule
142 expanded.
144 2. Access Authentication Framework
146 2.1. Challenge and Response
148 HTTP provides a simple challenge-response authentication mechanism
149 that can be used by a server to challenge a client request and by a
150 client to provide authentication information. It uses an extensible,
151 case-insensitive token to identify the authentication scheme,
152 followed by additional information necessary for achieving
153 authentication via that scheme. The latter can either be a comma-
154 separated list of parameters or a single sequence of characters
155 capable of holding base64-encoded information.
157 Parameters are name-value pairs where the name is matched case-
158 insensitively, and each parameter name MUST only occur once per
159 challenge.
161 auth-scheme = token
163 auth-param = token BWS "=" BWS ( token / quoted-string )
165 token68 = 1*( ALPHA / DIGIT /
166 "-" / "." / "_" / "~" / "+" / "/" ) *"="
168 The "token68" syntax allows the 66 unreserved URI characters
169 ([RFC3986]), plus a few others, so that it can hold a base64,
170 base64url (URL and filename safe alphabet), base32, or base16 (hex)
171 encoding, with or without padding, but excluding whitespace
172 ([RFC4648]).
174 The 401 (Unauthorized) response message is used by an origin server
175 to challenge the authorization of a user agent. This response MUST
176 include a WWW-Authenticate header field containing at least one
177 challenge applicable to the requested resource.
179 The 407 (Proxy Authentication Required) response message is used by a
180 proxy to challenge the authorization of a client and MUST include a
181 Proxy-Authenticate header field containing at least one challenge
182 applicable to the proxy for the requested resource.
184 challenge = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
186 Note: User agents will need to take special care in parsing the
187 WWW-Authenticate and Proxy-Authenticate header field values
188 because they can contain more than one challenge, or if more than
189 one of each is provided, since the contents of a challenge can
190 itself contain a comma-separated list of authentication
191 parameters.
193 Note: Many clients fail to parse challenges containing unknown
194 schemes. A workaround for this problem is to list well-supported
195 schemes (such as "basic") first.
197 A user agent that wishes to authenticate itself with an origin server
198 -- usually, but not necessarily, after receiving a 401 (Unauthorized)
199 -- can do so by including an Authorization header field with the
200 request.
202 A client that wishes to authenticate itself with a proxy -- usually,
203 but not necessarily, after receiving a 407 (Proxy Authentication
204 Required) -- can do so by including a Proxy-Authorization header
205 field with the request.
207 Both the Authorization field value and the Proxy-Authorization field
208 value contain the client's credentials for the realm of the resource
209 being requested, based upon a challenge received from the server
210 (possibly at some point in the past). When creating their values,
211 the user agent ought to do so by selecting the challenge with what it
212 considers to be the most secure auth-scheme that it understands,
213 obtaining credentials from the user as appropriate.
215 credentials = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
217 Upon a request for a protected resource that omits credentials,
218 contains invalid credentials (e.g., a bad password) or partial
219 credentials (e.g., when the authentication scheme requires more than
220 one round trip), an origin server SHOULD send a 401 (Unauthorized)
221 response that contains a WWW-Authenticate header field with at least
222 one (possibly new) challenge applicable to the requested resource.
224 Likewise, upon a request that requires authentication by proxies that
225 omit credentials or contain invalid or partial credentials, a proxy
226 SHOULD send a 407 (Proxy Authentication Required) response that
227 contains a Proxy-Authenticate header field with a (possibly new)
228 challenge applicable to the proxy.
230 A server receiving credentials that are valid, but not adequate to
231 gain access, ought to respond with the 403 (Forbidden) status code
232 (Section 6.5.3 of [Part2]).
234 The HTTP protocol does not restrict applications to this simple
235 challenge-response mechanism for access authentication. Additional
236 mechanisms MAY be used, such as encryption at the transport level or
237 via message encapsulation, and with additional header fields
238 specifying authentication information. However, such additional
239 mechanisms are not defined by this specification.
241 Proxies MUST forward the WWW-Authenticate and Authorization header
242 fields unmodified and follow the rules found in Section 4.1.
244 2.2. Protection Space (Realm)
246 The authentication parameter realm is reserved for use by
247 authentication schemes that wish to indicate the scope of protection.
249 A protection space is defined by the canonical root URI (the scheme
250 and authority components of the effective request URI; see Section
251 5.5 of [Part1]) of the server being accessed, in combination with the
252 realm value if present. These realms allow the protected resources
253 on a server to be partitioned into a set of protection spaces, each
254 with its own authentication scheme and/or authorization database.
255 The realm value is a string, generally assigned by the origin server,
256 that can have additional semantics specific to the authentication
257 scheme. Note that there can be multiple challenges with the same
258 auth-scheme but different realms.
260 The protection space determines the domain over which credentials can
261 be automatically applied. If a prior request has been authorized,
262 the same credentials MAY be reused for all other requests within that
263 protection space for a period of time determined by the
264 authentication scheme, parameters, and/or user preference. Unless
265 otherwise defined by the authentication scheme, a single protection
266 space cannot extend outside the scope of its server.
268 For historical reasons, senders MUST only use the quoted-string
269 syntax. Recipients might have to support both token and quoted-
270 string syntax for maximum interoperability with existing clients that
271 have been accepting both notations for a long time.
273 2.3. Authentication Scheme Registry
275 The HTTP Authentication Scheme Registry defines the name space for
276 the authentication schemes in challenges and credentials.
278 Registrations MUST include the following fields:
280 o Authentication Scheme Name
282 o Pointer to specification text
284 o Notes (optional)
286 Values to be added to this name space require IETF Review (see
287 [RFC5226], Section 4.1).
289 The registry itself is maintained at
290 .
292 2.3.1. Considerations for New Authentication Schemes
294 There are certain aspects of the HTTP Authentication Framework that
295 put constraints on how new authentication schemes can work:
297 o HTTP authentication is presumed to be stateless: all of the
298 information necessary to authenticate a request MUST be provided
299 in the request, rather than be dependent on the server remembering
300 prior requests. Authentication based on, or bound to, the
301 underlying connection is outside the scope of this specification
302 and inherently flawed unless steps are taken to ensure that the
303 connection cannot be used by any party other than the
304 authenticated user (see Section 2.3 of [Part1]).
306 o The authentication parameter "realm" is reserved for defining
307 Protection Spaces as defined in Section 2.2. New schemes MUST NOT
308 use it in a way incompatible with that definition.
310 o The "token68" notation was introduced for compatibility with
311 existing authentication schemes and can only be used once per
312 challenge/credentials. New schemes thus ought to use the "auth-
313 param" syntax instead, because otherwise future extensions will be
314 impossible.
316 o The parsing of challenges and credentials is defined by this
317 specification, and cannot be modified by new authentication
318 schemes. When the auth-param syntax is used, all parameters ought
319 to support both token and quoted-string syntax, and syntactical
320 constraints ought to be defined on the field value after parsing
321 (i.e., quoted-string processing). This is necessary so that
322 recipients can use a generic parser that applies to all
323 authentication schemes.
325 Note: The fact that the value syntax for the "realm" parameter is
326 restricted to quoted-string was a bad design choice not to be
327 repeated for new parameters.
329 o Definitions of new schemes ought to define the treatment of
330 unknown extension parameters. In general, a "must-ignore" rule is
331 preferable over "must-understand", because otherwise it will be
332 hard to introduce new parameters in the presence of legacy
333 recipients. Furthermore, it's good to describe the policy for
334 defining new parameters (such as "update the specification", or
335 "use this registry").
337 o Authentication schemes need to document whether they are usable in
338 origin-server authentication (i.e., using WWW-Authenticate),
339 and/or proxy authentication (i.e., using Proxy-Authenticate).
341 o The credentials carried in an Authorization header field are
342 specific to the User Agent, and therefore have the same effect on
343 HTTP caches as the "private" Cache-Control response directive,
344 within the scope of the request they appear in.
346 Therefore, new authentication schemes that choose not to carry
347 credentials in the Authorization header field (e.g., using a newly
348 defined header field) will need to explicitly disallow caching, by
349 mandating the use of either Cache-Control request directives
350 (e.g., "no-store") or response directives (e.g., "private").
352 3. Status Code Definitions
354 3.1. 401 Unauthorized
356 The 401 (Unauthorized) status code indicates that the request has not
357 been applied because it lacks valid authentication credentials for
358 the target resource. The origin server MUST send a WWW-Authenticate
359 header field (Section 4.4) containing at least one challenge
360 applicable to the target resource. If the request included
361 authentication credentials, then the 401 response indicates that
362 authorization has been refused for those credentials. The client MAY
363 repeat the request with a new or replaced Authorization header field
364 (Section 4.1). If the 401 response contains the same challenge as
365 the prior response, and the user agent has already attempted
366 authentication at least once, then the user agent SHOULD present the
367 enclosed representation to the user, since it usually contains
368 relevant diagnostic information.
370 3.2. 407 Proxy Authentication Required
372 The 407 (Proxy Authentication Required) status code is similar to 401
373 (Unauthorized), but indicates that the client needs to authenticate
374 itself in order to use a proxy. The proxy MUST send a Proxy-
375 Authenticate header field (Section 4.2) containing a challenge
376 applicable to that proxy for the target resource. The client MAY
377 repeat the request with a new or replaced Proxy-Authorization header
378 field (Section 4.3).
380 4. Header Field Definitions
382 This section defines the syntax and semantics of HTTP/1.1 header
383 fields related to authentication.
385 4.1. Authorization
387 The "Authorization" header field allows a user agent to authenticate
388 itself with a server -- usually, but not necessarily, after receiving
389 a 401 (Unauthorized) response. Its value consists of credentials
390 containing information of the user agent for the realm of the
391 resource being requested.
393 Authorization = credentials
395 If a request is authenticated and a realm specified, the same
396 credentials SHOULD be valid for all other requests within this realm
397 (assuming that the authentication scheme itself does not require
398 otherwise, such as credentials that vary according to a challenge
399 value or using synchronized clocks).
401 See Section 3.2 of [Part6] for details of and requirements pertaining
402 to handling of the Authorization field by HTTP caches.
404 4.2. Proxy-Authenticate
406 The "Proxy-Authenticate" header field consists of at least one
407 challenge that indicates the authentication scheme(s) and parameters
408 applicable to the proxy for this effective request URI (Section 5.5
409 of [Part1]). It MUST be included as part of a 407 (Proxy
410 Authentication Required) response.
412 Proxy-Authenticate = 1#challenge
414 Unlike WWW-Authenticate, the Proxy-Authenticate header field applies
415 only to the current connection, and intermediaries SHOULD NOT forward
416 it to downstream clients. However, an intermediate proxy might need
417 to obtain its own credentials by requesting them from the downstream
418 client, which in some circumstances will appear as if the proxy is
419 forwarding the Proxy-Authenticate header field.
421 Note that the parsing considerations for WWW-Authenticate apply to
422 this header field as well; see Section 4.4 for details.
424 4.3. Proxy-Authorization
426 The "Proxy-Authorization" header field allows the client to identify
427 itself (or its user) to a proxy that requires authentication. Its
428 value consists of credentials containing the authentication
429 information of the user agent for the proxy and/or realm of the
430 resource being requested.
432 Proxy-Authorization = credentials
434 Unlike Authorization, the Proxy-Authorization header field applies
435 only to the next outbound proxy that demanded authentication using
436 the Proxy-Authenticate field. When multiple proxies are used in a
437 chain, the Proxy-Authorization header field is consumed by the first
438 outbound proxy that was expecting to receive credentials. A proxy
439 MAY relay the credentials from the client request to the next proxy
440 if that is the mechanism by which the proxies cooperatively
441 authenticate a given request.
443 4.4. WWW-Authenticate
445 The "WWW-Authenticate" header field consists of at least one
446 challenge that indicates the authentication scheme(s) and parameters
447 applicable to the effective request URI (Section 5.5 of [Part1]).
449 It MUST be included in 401 (Unauthorized) response messages and MAY
450 be included in other response messages to indicate that supplying
451 credentials (or different credentials) might affect the response.
453 WWW-Authenticate = 1#challenge
455 User agents are advised to take special care in parsing the WWW-
456 Authenticate field value as it might contain more than one challenge,
457 or if more than one WWW-Authenticate header field is provided, the
458 contents of a challenge itself can contain a comma-separated list of
459 authentication parameters.
461 For instance:
463 WWW-Authenticate: Newauth realm="apps", type=1,
464 title="Login to \"apps\"", Basic realm="simple"
466 This header field contains two challenges; one for the "Newauth"
467 scheme with a realm value of "apps", and two additional parameters
468 "type" and "title", and another one for the "Basic" scheme with a
469 realm value of "simple".
471 Note: The challenge grammar production uses the list syntax as
472 well. Therefore, a sequence of comma, whitespace, and comma can
473 be considered both as applying to the preceding challenge, or to
474 be an empty entry in the list of challenges. In practice, this
475 ambiguity does not affect the semantics of the header field value
476 and thus is harmless.
478 5. IANA Considerations
480 5.1. Authentication Scheme Registry
482 The registration procedure for HTTP Authentication Schemes is defined
483 by Section 2.3 of this document.
485 The HTTP Method Authentication Scheme shall be created at
486 .
488 5.2. Status Code Registration
490 The HTTP Status Code Registry located at
491 shall be updated
492 with the registrations below:
494 +-------+-------------------------------+-------------+
495 | Value | Description | Reference |
496 +-------+-------------------------------+-------------+
497 | 401 | Unauthorized | Section 3.1 |
498 | 407 | Proxy Authentication Required | Section 3.2 |
499 +-------+-------------------------------+-------------+
501 5.3. Header Field Registration
503 The Message Header Field Registry located at shall be
505 updated with the permanent registrations below (see [BCP90]):
507 +---------------------+----------+----------+-------------+
508 | Header Field Name | Protocol | Status | Reference |
509 +---------------------+----------+----------+-------------+
510 | Authorization | http | standard | Section 4.1 |
511 | Proxy-Authenticate | http | standard | Section 4.2 |
512 | Proxy-Authorization | http | standard | Section 4.3 |
513 | WWW-Authenticate | http | standard | Section 4.4 |
514 +---------------------+----------+----------+-------------+
516 The change controller is: "IETF (iesg@ietf.org) - Internet
517 Engineering Task Force".
519 6. Security Considerations
521 This section is meant to inform developers, information providers,
522 and users of known security concerns specific to HTTP/1.1
523 authentication. More general security considerations are addressed
524 in HTTP messaging [Part1] and semantics [Part2].
526 6.1. Authentication Credentials and Idle Clients
528 Existing HTTP clients and user agents typically retain authentication
529 information indefinitely. HTTP/1.1 does not provide a method for a
530 server to direct clients to discard these cached credentials. This
531 is a significant defect that requires further extensions to HTTP.
532 Circumstances under which credential caching can interfere with the
533 application's security model include but are not limited to:
535 o Clients that have been idle for an extended period, following
536 which the server might wish to cause the client to re-prompt the
537 user for credentials.
539 o Applications that include a session termination indication (such
540 as a "logout" or "commit" button on a page) after which the server
541 side of the application "knows" that there is no further reason
542 for the client to retain the credentials.
544 This is currently under separate study. There are a number of work-
545 arounds to parts of this problem, and we encourage the use of
546 password protection in screen savers, idle time-outs, and other
547 methods that mitigate the security problems inherent in this problem.
548 In particular, user agents that cache credentials are encouraged to
549 provide a readily accessible mechanism for discarding cached
550 credentials under user control.
552 6.2. Protection Spaces
554 Authentication schemes that solely rely on the "realm" mechanism for
555 establishing a protection space will expose credentials to all
556 resources on a server. Clients that have successfully made
557 authenticated requests with a resource can use the same
558 authentication credentials for other resources on the same server.
559 This makes it possible for a different resource to harvest
560 authentication credentials for other resources.
562 This is of particular concern when a server hosts resources for
563 multiple parties under the same canonical root URI (Section 2.2).
564 Possible mitigation strategies include restricting direct access to
565 authentication credentials (i.e., not making the content of the
566 Authorization request header field available), and separating
567 protection spaces by using a different host name for each party.
569 7. Acknowledgments
571 This specification takes over the definition of the HTTP
572 Authentication Framework, previously defined in RFC 2617. We thank
573 John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D.
574 Lawrence, Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for
575 their work on that specification. See Section 6 of [RFC2617] for
576 further acknowledgements.
578 See Section 9 of [Part1] for the Acknowledgments related to this
579 document revision.
581 8. References
583 8.1. Normative References
585 [Part1] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
586 Protocol (HTTP/1.1): Message Syntax and Routing",
587 draft-ietf-httpbis-p1-messaging-22 (work in progress),
588 February 2013.
590 [Part2] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
591 Protocol (HTTP/1.1): Semantics and Content",
592 draft-ietf-httpbis-p2-semantics-22 (work in progress),
593 February 2013.
595 [Part6] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
596 Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
597 draft-ietf-httpbis-p6-cache-22 (work in progress),
598 February 2013.
600 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
601 Requirement Levels", BCP 14, RFC 2119, March 1997.
603 [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
604 Specifications: ABNF", STD 68, RFC 5234, January 2008.
606 8.2. Informative References
608 [BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration
609 Procedures for Message Header Fields", BCP 90, RFC 3864,
610 September 2004.
612 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
613 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
614 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
616 [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
617 Leach, P., Luotonen, A., and L. Stewart, "HTTP
618 Authentication: Basic and Digest Access Authentication",
619 RFC 2617, June 1999.
621 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
622 Resource Identifier (URI): Generic Syntax", STD 66,
623 RFC 3986, January 2005.
625 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
626 Encodings", RFC 4648, October 2006.
628 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
629 IANA Considerations Section in RFCs", BCP 26, RFC 5226,
630 May 2008.
632 Appendix A. Changes from RFCs 2616 and 2617
634 The framework for HTTP Authentication is now defined by this
635 document, rather than RFC 2617.
637 The "realm" parameter is no longer always required on challenges;
638 consequently, the ABNF allows challenges without any auth parameters.
639 (Section 2)
641 The "token68" alternative to auth-param lists has been added for
642 consistency with legacy authentication schemes such as "Basic".
643 (Section 2)
645 This specification introduces the Authentication Scheme Registry,
646 along with considerations for new authentication schemes.
647 (Section 2.3)
649 Appendix B. Imported ABNF
651 The following core rules are included by reference, as defined in
652 Appendix B.1 of [RFC5234]: ALPHA (letters), CR (carriage return),
653 CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double
654 quote), HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any
655 8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII
656 character).
658 The rules below are defined in [Part1]:
660 BWS =
661 OWS =
662 quoted-string =
663 token =
665 Appendix C. Collected ABNF
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 first Working Group Last Call draft are summarized
697 in .
700 D.1. Since draft-ietf-httpbis-p7-auth-19
702 Closed issues:
704 o : "Realms and
705 scope"
707 o : "Strength"
709 o :
710 "Authentication exchanges"
712 o : "ABNF
713 requirements for recipients"
715 o : "note
716 introduction of new IANA registries as normative changes"
718 D.2. Since draft-ietf-httpbis-p7-auth-20
720 Closed issues:
722 o : "rename
723 b64token for clarity"
725 Other changes:
727 o Conformance criteria and considerations regarding error handling
728 are now defined in Part 1.
730 D.3. Since draft-ietf-httpbis-p7-auth-21
732 Closed issues:
734 o :
735 "Authentication and caching - max-age"
737 Index
739 4
740 401 Unauthorized (status code) 9
741 407 Proxy Authentication Required (status code) 9
743 A
744 Authorization header field 9
746 C
747 Canonical Root URI 6
749 G
750 Grammar
751 auth-param 5
752 auth-scheme 5
753 Authorization 9
754 challenge 5
755 credentials 6
756 Proxy-Authenticate 10
757 Proxy-Authorization 10
758 token68 5
759 WWW-Authenticate 11
761 P
762 Protection Space 6
763 Proxy-Authenticate header field 10
764 Proxy-Authorization header field 10
766 R
767 Realm 6
769 W
770 WWW-Authenticate header field 10
772 Authors' Addresses
774 Roy T. Fielding (editor)
775 Adobe Systems Incorporated
776 345 Park Ave
777 San Jose, CA 95110
778 USA
780 EMail: fielding@gbiv.com
781 URI: http://roy.gbiv.com/
783 Julian F. Reschke (editor)
784 greenbytes GmbH
785 Hafenweg 16
786 Muenster, NW 48155
787 Germany
789 EMail: julian.reschke@greenbytes.de
790 URI: http://greenbytes.de/tech/webdav/