rfc7235.txt   draft-ietf-httpbis-auth-00.txt 
Internet Engineering Task Force (IETF) R. Fielding, Ed. HTTP Working Group R. Fielding, Ed.
Request for Comments: 7235 Adobe Internet-Draft Adobe
Obsoletes: 2616 J. Reschke, Ed. Obsoletes: 7235 (if approved) M. Nottingham, Ed.
Updates: 2617 greenbytes Updates: 2617 (if approved) Fastly
Category: Standards Track June 2014 Intended status: Standards Track J. Reschke, Ed.
ISSN: 2070-1721 Expires: October 5, 2018 greenbytes
April 3, 2018
Hypertext Transfer Protocol (HTTP/1.1): Authentication Hypertext Transfer Protocol (HTTP): Authentication
draft-ietf-httpbis-auth-00
Abstract Abstract
The Hypertext Transfer Protocol (HTTP) is a stateless application- The Hypertext Transfer Protocol (HTTP) is a stateless application-
level protocol for distributed, collaborative, hypermedia information level protocol for distributed, collaborative, hypermedia information
systems. This document defines the HTTP Authentication framework. systems. This document defines the HTTP Authentication framework.
This document obsoletes RFC 7235.
Editorial Note
This note is to be removed before publishing as an RFC.
Discussion of this draft takes place on the HTTP working group
mailing list (ietf-http-wg@w3.org), which is archived at
<http://lists.w3.org/Archives/Public/ietf-http-wg/>.
Working Group information can be found at <http://httpwg.github.io/>;
source code and issues list for this draft can be found at
<https://github.com/httpwg/http-core>.
The changes in this draft are summarized in Appendix D.1.
Status of This Memo Status of This Memo
This is an Internet Standards Track document. This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
This document is a product of the Internet Engineering Task Force Internet-Drafts are working documents of the Internet Engineering
(IETF). It represents the consensus of the IETF community. It has Task Force (IETF). Note that other groups may also distribute
received public review and has been approved for publication by the working documents as Internet-Drafts. The list of current Internet-
Internet Engineering Steering Group (IESG). Further information on Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata, Internet-Drafts are draft documents valid for a maximum of six months
and how to provide feedback on it may be obtained at and may be updated, replaced, or obsoleted by other documents at any
http://www.rfc-editor.org/info/rfc7235. time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 5, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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This document may contain material from IETF Documents or IETF This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November Contributions published or made publicly available before November
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modifications of such material outside the IETF Standards Process. modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling Without obtaining an adequate license from the person(s) controlling
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it for publication as an RFC or to translate it into languages other it for publication as an RFC or to translate it into languages other
than English. than English.
Table of Contents Table of Contents
1. Introduction ....................................................3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conformance and Error Handling .............................3 1.1. Conformance and Error Handling . . . . . . . . . . . . . 3
1.2. Syntax Notation ............................................3 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 4
2. Access Authentication Framework .................................3 2. Access Authentication Framework . . . . . . . . . . . . . . . 4
2.1. Challenge and Response .....................................3 2.1. Challenge and Response . . . . . . . . . . . . . . . . . 4
2.2. Protection Space (Realm) ...................................5 2.2. Protection Space (Realm) . . . . . . . . . . . . . . . . 6
3. Status Code Definitions .........................................6 3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 6
3.1. 401 Unauthorized ...........................................6 3.1. 401 Unauthorized . . . . . . . . . . . . . . . . . . . . 7
3.2. 407 Proxy Authentication Required ..........................6 3.2. 407 Proxy Authentication Required . . . . . . . . . . . . 7
4. Header Field Definitions ........................................7 4. Header Field Definitions . . . . . . . . . . . . . . . . . . 7
4.1. WWW-Authenticate ...........................................7 4.1. WWW-Authenticate . . . . . . . . . . . . . . . . . . . . 7
4.2. Authorization ..............................................8 4.2. Authorization . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Proxy-Authenticate .........................................8 4.3. Proxy-Authenticate . . . . . . . . . . . . . . . . . . . 9
4.4. Proxy-Authorization ........................................9 4.4. Proxy-Authorization . . . . . . . . . . . . . . . . . . . 9
5. IANA Considerations .............................................9 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5.1. Authentication Scheme Registry .............................9 5.1. Authentication Scheme Registry . . . . . . . . . . . . . 10
5.1.1. Procedure ...........................................9 5.1.1. Procedure . . . . . . . . . . . . . . . . . . . . . . 10
5.1.2. Considerations for New Authentication Schemes ......10 5.1.2. Considerations for New Authentication Schemes . . . . 10
5.2. Status Code Registration ..................................11 5.2. Status Code Registration . . . . . . . . . . . . . . . . 12
5.3. Header Field Registration .................................11 5.3. Header Field Registration . . . . . . . . . . . . . . . . 12
6. Security Considerations ........................................12 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
6.1. Confidentiality of Credentials ............................12 6.1. Confidentiality of Credentials . . . . . . . . . . . . . 13
6.2. Authentication Credentials and Idle Clients ...............12 6.2. Authentication Credentials and Idle Clients . . . . . . . 13
6.3. Protection Spaces .........................................13 6.3. Protection Spaces . . . . . . . . . . . . . . . . . . . . 14
7. Acknowledgments ................................................14 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
8. References .....................................................14 7.1. Normative References . . . . . . . . . . . . . . . . . . 14
8.1. Normative References ......................................14 7.2. Informative References . . . . . . . . . . . . . . . . . 15
8.2. Informative References ....................................14 Appendix A. Changes from RFC 7235 . . . . . . . . . . . . . . . 16
Appendix A. Changes from RFCs 2616 and 2617 .......................16 Appendix B. Imported ABNF . . . . . . . . . . . . . . . . . . . 16
Appendix B. Imported ABNF .........................................16 Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 16
Appendix C. Collected ABNF ........................................17 Appendix D. Change Log . . . . . . . . . . . . . . . . . . . . . 17
Index .............................................................18 D.1. Since RFC 7235 . . . . . . . . . . . . . . . . . . . . . 17
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
HTTP provides a general framework for access control and HTTP provides a general framework for access control and
authentication, via an extensible set of challenge-response authentication, via an extensible set of challenge-response
authentication schemes, which can be used by a server to challenge a authentication schemes, which can be used by a server to challenge a
client request and by a client to provide authentication information. client request and by a client to provide authentication information.
This document defines HTTP/1.1 authentication in terms of the This document defines HTTP/1.1 authentication in terms of the
architecture defined in "Hypertext Transfer Protocol (HTTP/1.1): architecture defined in "Hypertext Transfer Protocol (HTTP/1.1):
Message Syntax and Routing" [RFC7230], including the general Message Syntax and Routing" [MESSGNG].
framework previously described in "HTTP Authentication: Basic and
Digest Access Authentication" [RFC2617] and the related fields and
status codes previously defined in "Hypertext Transfer Protocol --
HTTP/1.1" [RFC2616].
The IANA Authentication Scheme Registry (Section 5.1) lists The IANA Authentication Scheme Registry (Section 5.1) lists
registered authentication schemes and their corresponding registered authentication schemes and their corresponding
specifications, including the "basic" and "digest" authentication specifications.
schemes previously defined by RFC 2617.
This specification obsoletes RFC 7235, with the changes being
summarized in Appendix A.
1.1. Conformance and Error Handling 1.1. Conformance and Error Handling
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
Conformance criteria and considerations regarding error handling are Conformance criteria and considerations regarding error handling are
defined in Section 2.5 of [RFC7230]. defined in Section 2.5 of [MESSGNG].
1.2. Syntax Notation 1.2. Syntax Notation
This specification uses the Augmented Backus-Naur Form (ABNF) This specification uses the Augmented Backus-Naur Form (ABNF)
notation of [RFC5234] with a list extension, defined in Section 7 of notation of [RFC5234] with a list extension, defined in Section 7 of
[RFC7230], that allows for compact definition of comma-separated [MESSGNG], that allows for compact definition of comma-separated
lists using a '#' operator (similar to how the '*' operator indicates lists using a '#' operator (similar to how the '*' operator indicates
repetition). Appendix B describes rules imported from other repetition). Appendix B describes rules imported from other
documents. Appendix C shows the collected grammar with all list documents. Appendix C shows the collected grammar with all list
operators expanded to standard ABNF notation. operators expanded to standard ABNF notation.
2. Access Authentication Framework 2. Access Authentication Framework
2.1. Challenge and Response 2.1. Challenge and Response
HTTP provides a simple challenge-response authentication framework HTTP provides a simple challenge-response authentication framework
skipping to change at page 4, line 26 skipping to change at page 4, line 46
token68 = 1*( ALPHA / DIGIT / token68 = 1*( ALPHA / DIGIT /
"-" / "." / "_" / "~" / "+" / "/" ) *"=" "-" / "." / "_" / "~" / "+" / "/" ) *"="
The token68 syntax allows the 66 unreserved URI characters The token68 syntax allows the 66 unreserved URI characters
([RFC3986]), plus a few others, so that it can hold a base64, ([RFC3986]), plus a few others, so that it can hold a base64,
base64url (URL and filename safe alphabet), base32, or base16 (hex) base64url (URL and filename safe alphabet), base32, or base16 (hex)
encoding, with or without padding, but excluding whitespace encoding, with or without padding, but excluding whitespace
([RFC4648]). ([RFC4648]).
A 401 (Unauthorized) response message is used by an origin server to A 401 (Unauthorized) response message is used by an origin server to
challenge the authorization of a user agent, including a challenge the authorization of a user agent, including a WWW-
WWW-Authenticate header field containing at least one challenge Authenticate header field containing at least one challenge
applicable to the requested resource. applicable to the requested resource.
A 407 (Proxy Authentication Required) response message is used by a A 407 (Proxy Authentication Required) response message is used by a
proxy to challenge the authorization of a client, including a proxy to challenge the authorization of a client, including a Proxy-
Proxy-Authenticate header field containing at least one challenge Authenticate header field containing at least one challenge
applicable to the proxy for the requested resource. applicable to the proxy for the requested resource.
challenge = auth-scheme [ 1*SP ( token68 / #auth-param ) ] challenge = auth-scheme [ 1*SP ( token68 / #auth-param ) ]
Note: Many clients fail to parse a challenge that contains an Note: Many clients fail to parse a challenge that contains an
unknown scheme. A workaround for this problem is to list well- unknown scheme. A workaround for this problem is to list well-
supported schemes (such as "basic") first. supported schemes (such as "basic") first.
A user agent that wishes to authenticate itself with an origin server A user agent that wishes to authenticate itself with an origin server
-- usually, but not necessarily, after receiving a 401 (Unauthorized) -- usually, but not necessarily, after receiving a 401 (Unauthorized)
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requested resource. requested resource.
Likewise, upon receipt of a request that omits proxy credentials or Likewise, upon receipt of a request that omits proxy credentials or
contains invalid or partial proxy credentials, a proxy that requires contains invalid or partial proxy credentials, a proxy that requires
authentication SHOULD generate a 407 (Proxy Authentication Required) authentication SHOULD generate a 407 (Proxy Authentication Required)
response that contains a Proxy-Authenticate header field with at response that contains a Proxy-Authenticate header field with at
least one (possibly new) challenge applicable to the proxy. least one (possibly new) challenge applicable to the proxy.
A server that receives valid credentials that are not adequate to A server that receives valid credentials that are not adequate to
gain access ought to respond with the 403 (Forbidden) status code gain access ought to respond with the 403 (Forbidden) status code
(Section 6.5.3 of [RFC7231]). (Section 6.5.3 of [SEMNTCS]).
HTTP does not restrict applications to this simple challenge-response HTTP does not restrict applications to this simple challenge-response
framework for access authentication. Additional mechanisms can be framework for access authentication. Additional mechanisms can be
used, such as authentication at the transport level or via message used, such as authentication at the transport level or via message
encapsulation, and with additional header fields specifying encapsulation, and with additional header fields specifying
authentication information. However, such additional mechanisms are authentication information. However, such additional mechanisms are
not defined by this specification. not defined by this specification.
2.2. Protection Space (Realm) 2.2. Protection Space (Realm)
The "realm" authentication parameter is reserved for use by The "realm" authentication parameter is reserved for use by
authentication schemes that wish to indicate a scope of protection. authentication schemes that wish to indicate a scope of protection.
A protection space is defined by the canonical root URI (the scheme A protection space is defined by the canonical root URI (the scheme
and authority components of the effective request URI; see Section and authority components of the effective request URI; see
5.5 of [RFC7230]) of the server being accessed, in combination with Section 5.5 of [MESSGNG]) of the server being accessed, in
the realm value if present. These realms allow the protected combination with the realm value if present. These realms allow the
resources on a server to be partitioned into a set of protection protected resources on a server to be partitioned into a set of
spaces, each with its own authentication scheme and/or authorization protection spaces, each with its own authentication scheme and/or
database. The realm value is a string, generally assigned by the authorization database. The realm value is a string, generally
origin server, that can have additional semantics specific to the assigned by the origin server, that can have additional semantics
authentication scheme. Note that a response can have multiple specific to the authentication scheme. Note that a response can have
challenges with the same auth-scheme but with different realms. multiple challenges with the same auth-scheme but with different
realms.
The protection space determines the domain over which credentials can The protection space determines the domain over which credentials can
be automatically applied. If a prior request has been authorized, be automatically applied. If a prior request has been authorized,
the user agent MAY reuse the same credentials for all other requests the user agent MAY reuse the same credentials for all other requests
within that protection space for a period of time determined by the within that protection space for a period of time determined by the
authentication scheme, parameters, and/or user preferences (such as a authentication scheme, parameters, and/or user preferences (such as a
configurable inactivity timeout). Unless specifically allowed by the configurable inactivity timeout). Unless specifically allowed by the
authentication scheme, a single protection space cannot extend authentication scheme, a single protection space cannot extend
outside the scope of its server. outside the scope of its server.
For historical reasons, a sender MUST only generate the quoted-string For historical reasons, a sender MUST only generate the quoted-string
syntax. Recipients might have to support both token and syntax. Recipients might have to support both token and quoted-
quoted-string syntax for maximum interoperability with existing string syntax for maximum interoperability with existing clients that
clients that have been accepting both notations for a long time. have been accepting both notations for a long time.
3. Status Code Definitions 3. Status Code Definitions
3.1. 401 Unauthorized 3.1. 401 Unauthorized
The 401 (Unauthorized) status code indicates that the request has not The 401 (Unauthorized) status code indicates that the request has not
been applied because it lacks valid authentication credentials for been applied because it lacks valid authentication credentials for
the target resource. The server generating a 401 response MUST send the target resource. The server generating a 401 response MUST send
a WWW-Authenticate header field (Section 4.1) containing at least one a WWW-Authenticate header field (Section 4.1) containing at least one
challenge applicable to the target resource. challenge applicable to the target resource.
If the request included authentication credentials, then the 401 If the request included authentication credentials, then the 401
response indicates that authorization has been refused for those response indicates that authorization has been refused for those
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This section defines the syntax and semantics of header fields This section defines the syntax and semantics of header fields
related to the HTTP authentication framework. related to the HTTP authentication framework.
4.1. WWW-Authenticate 4.1. WWW-Authenticate
The "WWW-Authenticate" header field indicates the authentication The "WWW-Authenticate" header field indicates the authentication
scheme(s) and parameters applicable to the target resource. scheme(s) and parameters applicable to the target resource.
WWW-Authenticate = 1#challenge WWW-Authenticate = 1#challenge
A server generating a 401 (Unauthorized) response MUST send a A server generating a 401 (Unauthorized) response MUST send a WWW-
WWW-Authenticate header field containing at least one challenge. A Authenticate header field containing at least one challenge. A
server MAY generate a WWW-Authenticate header field in other response server MAY generate a WWW-Authenticate header field in other response
messages to indicate that supplying credentials (or different messages to indicate that supplying credentials (or different
credentials) might affect the response. credentials) might affect the response.
A proxy forwarding a response MUST NOT modify any WWW-Authenticate A proxy forwarding a response MUST NOT modify any WWW-Authenticate
fields in that response. fields in that response.
User agents are advised to take special care in parsing the field User agents are advised to take special care in parsing the field
value, as it might contain more than one challenge, and each value, as it might contain more than one challenge, and each
challenge can contain a comma-separated list of authentication challenge can contain a comma-separated list of authentication
skipping to change at page 8, line 22 skipping to change at page 8, line 45
Authorization = credentials Authorization = credentials
If a request is authenticated and a realm specified, the same If a request is authenticated and a realm specified, the same
credentials are presumed to be valid for all other requests within credentials are presumed to be valid for all other requests within
this realm (assuming that the authentication scheme itself does not this realm (assuming that the authentication scheme itself does not
require otherwise, such as credentials that vary according to a require otherwise, such as credentials that vary according to a
challenge value or using synchronized clocks). challenge value or using synchronized clocks).
A proxy forwarding a request MUST NOT modify any Authorization fields A proxy forwarding a request MUST NOT modify any Authorization fields
in that request. See Section 3.2 of [RFC7234] for details of and in that request. See Section 3.2 of [CACHING] for details of and
requirements pertaining to handling of the Authorization field by requirements pertaining to handling of the Authorization field by
HTTP caches. HTTP caches.
4.3. Proxy-Authenticate 4.3. Proxy-Authenticate
The "Proxy-Authenticate" header field consists of at least one The "Proxy-Authenticate" header field consists of at least one
challenge that indicates the authentication scheme(s) and parameters challenge that indicates the authentication scheme(s) and parameters
applicable to the proxy for this effective request URI (Section 5.5 applicable to the proxy for this effective request URI (Section 5.5
of [RFC7230]). A proxy MUST send at least one Proxy-Authenticate of [MESSGNG]). A proxy MUST send at least one Proxy-Authenticate
header field in each 407 (Proxy Authentication Required) response header field in each 407 (Proxy Authentication Required) response
that it generates. that it generates.
Proxy-Authenticate = 1#challenge Proxy-Authenticate = 1#challenge
Unlike WWW-Authenticate, the Proxy-Authenticate header field applies Unlike WWW-Authenticate, the Proxy-Authenticate header field applies
only to the next outbound client on the response chain. This is only to the next outbound client on the response chain. This is
because only the client that chose a given proxy is likely to have because only the client that chose a given proxy is likely to have
the credentials necessary for authentication. However, when multiple the credentials necessary for authentication. However, when multiple
proxies are used within the same administrative domain, such as proxies are used within the same administrative domain, such as
skipping to change at page 10, line 17 skipping to change at page 10, line 39
There are certain aspects of the HTTP Authentication Framework that There are certain aspects of the HTTP Authentication Framework that
put constraints on how new authentication schemes can work: put constraints on how new authentication schemes can work:
o HTTP authentication is presumed to be stateless: all of the o HTTP authentication is presumed to be stateless: all of the
information necessary to authenticate a request MUST be provided information necessary to authenticate a request MUST be provided
in the request, rather than be dependent on the server remembering in the request, rather than be dependent on the server remembering
prior requests. Authentication based on, or bound to, the prior requests. Authentication based on, or bound to, the
underlying connection is outside the scope of this specification underlying connection is outside the scope of this specification
and inherently flawed unless steps are taken to ensure that the and inherently flawed unless steps are taken to ensure that the
connection cannot be used by any party other than the connection cannot be used by any party other than the
authenticated user (see Section 2.3 of [RFC7230]). authenticated user (see Section 2.3 of [MESSGNG]).
o The authentication parameter "realm" is reserved for defining o The authentication parameter "realm" is reserved for defining
protection spaces as described in Section 2.2. New schemes MUST protection spaces as described in Section 2.2. New schemes MUST
NOT use it in a way incompatible with that definition. NOT use it in a way incompatible with that definition.
o The "token68" notation was introduced for compatibility with o The "token68" notation was introduced for compatibility with
existing authentication schemes and can only be used once per existing authentication schemes and can only be used once per
challenge or credential. Thus, new schemes ought to use the challenge or credential. Thus, new schemes ought to use the auth-
auth-param syntax instead, because otherwise future extensions param syntax instead, because otherwise future extensions will be
will be impossible. impossible.
o The parsing of challenges and credentials is defined by this o The parsing of challenges and credentials is defined by this
specification and cannot be modified by new authentication specification and cannot be modified by new authentication
schemes. When the auth-param syntax is used, all parameters ought schemes. When the auth-param syntax is used, all parameters ought
to support both token and quoted-string syntax, and syntactical to support both token and quoted-string syntax, and syntactical
constraints ought to be defined on the field value after parsing constraints ought to be defined on the field value after parsing
(i.e., quoted-string processing). This is necessary so that (i.e., quoted-string processing). This is necessary so that
recipients can use a generic parser that applies to all recipients can use a generic parser that applies to all
authentication schemes. authentication schemes.
skipping to change at page 10, line 51 skipping to change at page 11, line 29
o Definitions of new schemes ought to define the treatment of o Definitions of new schemes ought to define the treatment of
unknown extension parameters. In general, a "must-ignore" rule is unknown extension parameters. In general, a "must-ignore" rule is
preferable to a "must-understand" rule, because otherwise it will preferable to a "must-understand" rule, because otherwise it will
be hard to introduce new parameters in the presence of legacy be hard to introduce new parameters in the presence of legacy
recipients. Furthermore, it's good to describe the policy for recipients. Furthermore, it's good to describe the policy for
defining new parameters (such as "update the specification" or defining new parameters (such as "update the specification" or
"use this registry"). "use this registry").
o Authentication schemes need to document whether they are usable in o Authentication schemes need to document whether they are usable in
origin-server authentication (i.e., using WWW-Authenticate), origin-server authentication (i.e., using WWW-Authenticate), and/
and/or proxy authentication (i.e., using Proxy-Authenticate). or proxy authentication (i.e., using Proxy-Authenticate).
o The credentials carried in an Authorization header field are o The credentials carried in an Authorization header field are
specific to the user agent and, therefore, have the same effect on specific to the user agent and, therefore, have the same effect on
HTTP caches as the "private" Cache-Control response directive HTTP caches as the "private" Cache-Control response directive
(Section 5.2.2.6 of [RFC7234]), within the scope of the request in (Section 5.2.2.6 of [CACHING]), within the scope of the request in
which they appear. which they appear.
Therefore, new authentication schemes that choose not to carry Therefore, new authentication schemes that choose not to carry
credentials in the Authorization header field (e.g., using a newly credentials in the Authorization header field (e.g., using a newly
defined header field) will need to explicitly disallow caching, by defined header field) will need to explicitly disallow caching, by
mandating the use of either Cache-Control request directives mandating the use of either Cache-Control request directives
(e.g., "no-store", Section 5.2.1.5 of [RFC7234]) or response (e.g., "no-store", Section 5.2.1.5 of [CACHING]) or response
directives (e.g., "private"). directives (e.g., "private").
5.2. Status Code Registration 5.2. Status Code Registration
The "Hypertext Transfer Protocol (HTTP) Status Code Registry" located The "Hypertext Transfer Protocol (HTTP) Status Code Registry" located
at <http://www.iana.org/assignments/http-status-codes> has been at <http://www.iana.org/assignments/http-status-codes> has been
updated with the registrations below: updated with the registrations below:
+-------+-------------------------------+-------------+ +-------+-------------------------------+--------------+
| Value | Description | Reference | | Value | Description | Reference |
+-------+-------------------------------+-------------+ +-------+-------------------------------+--------------+
| 401 | Unauthorized | Section 3.1 | | 401 | Unauthorized | Section 3.1 |
| 407 | Proxy Authentication Required | Section 3.2 | | 407 | Proxy Authentication Required | Section 3.2 |
+-------+-------------------------------+-------------+ +-------+-------------------------------+--------------+
5.3. Header Field Registration 5.3. Header Field Registration
HTTP header fields are registered within the "Message Headers" HTTP header fields are registered within the "Message Headers"
registry maintained at registry maintained at <http://www.iana.org/assignments/message-
<http://www.iana.org/assignments/message-headers/>. headers/>.
This document defines the following HTTP header fields, so the This document defines the following HTTP header fields, so the
"Permanent Message Header Field Names" registry has been updated "Permanent Message Header Field Names" registry has been updated
accordingly (see [BCP90]). accordingly (see [BCP90]).
+---------------------+----------+----------+-------------+ +---------------------+----------+----------+--------------+
| Header Field Name | Protocol | Status | Reference | | Header Field Name | Protocol | Status | Reference |
+---------------------+----------+----------+-------------+ +---------------------+----------+----------+--------------+
| Authorization | http | standard | Section 4.2 | | Authorization | http | standard | Section 4.2 |
| Proxy-Authenticate | http | standard | Section 4.3 | | Proxy-Authenticate | http | standard | Section 4.3 |
| Proxy-Authorization | http | standard | Section 4.4 | | Proxy-Authorization | http | standard | Section 4.4 |
| WWW-Authenticate | http | standard | Section 4.1 | | WWW-Authenticate | http | standard | Section 4.1 |
+---------------------+----------+----------+-------------+ +---------------------+----------+----------+--------------+
The change controller is: "IETF (iesg@ietf.org) - Internet The change controller is: "IETF (iesg@ietf.org) - Internet
Engineering Task Force". Engineering Task Force".
6. Security Considerations 6. Security Considerations
This section is meant to inform developers, information providers, This section is meant to inform developers, information providers,
and users of known security concerns specific to HTTP authentication. and users of known security concerns specific to HTTP authentication.
More general security considerations are addressed in HTTP messaging More general security considerations are addressed in HTTP messaging
[RFC7230] and semantics [RFC7231]. [MESSGNG] and semantics [SEMNTCS].
Everything about the topic of HTTP authentication is a security Everything about the topic of HTTP authentication is a security
consideration, so the list of considerations below is not exhaustive. consideration, so the list of considerations below is not exhaustive.
Furthermore, it is limited to security considerations regarding the Furthermore, it is limited to security considerations regarding the
authentication framework, in general, rather than discussing all of authentication framework, in general, rather than discussing all of
the potential considerations for specific authentication schemes the potential considerations for specific authentication schemes
(which ought to be documented in the specifications that define those (which ought to be documented in the specifications that define those
schemes). Various organizations maintain topical information and schemes). Various organizations maintain topical information and
links to current research on Web application security (e.g., links to current research on Web application security (e.g.,
[OWASP]), including common pitfalls for implementing and using the [OWASP]), including common pitfalls for implementing and using the
skipping to change at page 14, line 5 skipping to change at page 14, line 29
authentication credentials for other resources. authentication credentials for other resources.
This is of particular concern when an origin server hosts resources This is of particular concern when an origin server hosts resources
for multiple parties under the same canonical root URI (Section 2.2). for multiple parties under the same canonical root URI (Section 2.2).
Possible mitigation strategies include restricting direct access to Possible mitigation strategies include restricting direct access to
authentication credentials (i.e., not making the content of the authentication credentials (i.e., not making the content of the
Authorization request header field available), and separating Authorization request header field available), and separating
protection spaces by using a different host name (or port number) for protection spaces by using a different host name (or port number) for
each party. each party.
7. Acknowledgments 7. References
This specification takes over the definition of the HTTP
Authentication Framework, previously defined in RFC 2617. We thank
John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott D.
Lawrence, Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart for
their work on that specification. See Section 6 of [RFC2617] for
further acknowledgements.
See Section 10 of [RFC7230] for the Acknowledgments related to this 7.1. Normative References
document revision.
8. References [CACHING] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "Hypertext Transfer Protocol (HTTP): Caching", draft-
ietf-httpbis-cache-00 (work in progress), April 2018.
8.1. Normative References [MESSGNG] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "Hypertext Transfer Protocol (HTTP/1.1): Message
Syntax and Routing", draft-ietf-httpbis-messaging-00 (work
in progress), April 2018.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer <https://www.rfc-editor.org/info/rfc5234>.
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, June 2014.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
June 2014.
[RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, [SEMNTCS] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching", Ed., "Hypertext Transfer Protocol (HTTP): Semantics and
RFC 7234, June 2014. Content", draft-ietf-httpbis-semantics-00 (work in
progress), April 2018.
8.2. Informative References 7.2. Informative References
[BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration [BCP90] Klyne, G., Nottingham, M., and J. Mogul, "Registration
Procedures for Message Header Fields", BCP 90, RFC 3864, Procedures for Message Header Fields", BCP 90, RFC 3864,
September 2004. September 2004, <https://www.rfc-editor.org/info/bcp90>.
[OWASP] van der Stock, A., Ed., "A Guide to Building Secure Web [OWASP] van der Stock, A., Ed., "A Guide to Building Secure Web
Applications and Web Services", The Open Web Application Applications and Web Services", The Open Web Application
Security Project (OWASP) 2.0.1, July 2005, Security Project (OWASP) 2.0.1, July 2005,
<https://www.owasp.org/>. <https://www.owasp.org/>.
[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A., and L. Stewart, "HTTP Leach, P., Luotonen, A., and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication", Authentication: Basic and Digest Access Authentication",
RFC 2617, June 1999. RFC 2617, DOI 10.17487/RFC2617, June 1999,
<https://www.rfc-editor.org/info/rfc2617>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005. RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, October 2006. Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/info/rfc4648>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. DOI 10.17487/RFC5226, May 2008,
<https://www.rfc-editor.org/info/rfc5226>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
Appendix A. Changes from RFCs 2616 and 2617 <https://www.rfc-editor.org/info/rfc5246>.
The framework for HTTP Authentication is now defined by this
document, rather than RFC 2617.
The "realm" parameter is no longer always required on challenges; [RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
consequently, the ABNF allows challenges without any auth parameters. Protocol (HTTP/1.1): Authentication", RFC 7235,
(Section 2) DOI 10.17487/RFC7235, June 2014,
<https://www.rfc-editor.org/info/rfc7235>.
The "token68" alternative to auth-param lists has been added for Appendix A. Changes from RFC 7235
consistency with legacy authentication schemes such as "Basic".
(Section 2)
This specification introduces the Authentication Scheme Registry, None yet.
along with considerations for new authentication schemes.
(Section 5.1)
Appendix B. Imported ABNF Appendix B. Imported ABNF
The following core rules are included by reference, as defined in The following core rules are included by reference, as defined in
Appendix B.1 of [RFC5234]: ALPHA (letters), CR (carriage return), Appendix B.1 of [RFC5234]: ALPHA (letters), CR (carriage return),
CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double
quote), HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any quote), HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any
8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII 8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII
character). character).
The rules below are defined in [RFC7230]: The rules below are defined in [MESSGNG]:
BWS = <BWS, see [RFC7230], Section 3.2.3> BWS = <BWS, see [MESSGNG], Section 3.2.3>
OWS = <OWS, see [RFC7230], Section 3.2.3> OWS = <OWS, see [MESSGNG], Section 3.2.3>
quoted-string = <quoted-string, see [RFC7230], Section 3.2.6> quoted-string = <quoted-string, see [MESSGNG], Section 3.2.6>
token = <token, see [RFC7230], Section 3.2.6> token = <token, see [MESSGNG], Section 3.2.6>
Appendix C. Collected ABNF Appendix C. Collected ABNF
In the collected ABNF below, list rules are expanded as per Section In the collected ABNF below, list rules are expanded as per
1.2 of [RFC7230]. Section 1.2 of [MESSGNG].
Authorization = credentials Authorization = credentials
BWS = <BWS, see [RFC7230], Section 3.2.3> BWS = <BWS, see [MESSGNG], Section 3.2.3>
OWS = <OWS, see [RFC7230], Section 3.2.3> OWS = <OWS, see [MESSGNG], Section 3.2.3>
Proxy-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS Proxy-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS
challenge ] ) challenge ] )
Proxy-Authorization = credentials Proxy-Authorization = credentials
WWW-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS challenge WWW-Authenticate = *( "," OWS ) challenge *( OWS "," [ OWS challenge
] ) ] )
auth-param = token BWS "=" BWS ( token / quoted-string ) auth-param = token BWS "=" BWS ( token / quoted-string )
auth-scheme = token auth-scheme = token
challenge = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param ) *( challenge = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param ) *(
OWS "," [ OWS auth-param ] ) ] ) ] OWS "," [ OWS auth-param ] ) ] ) ]
credentials = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param ) credentials = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param )
*( OWS "," [ OWS auth-param ] ) ] ) ] *( OWS "," [ OWS auth-param ] ) ] ) ]
quoted-string = <quoted-string, see [RFC7230], Section 3.2.6> quoted-string = <quoted-string, see [MESSGNG], Section 3.2.6>
token = <token, see [RFC7230], Section 3.2.6> token = <token, see [MESSGNG], Section 3.2.6>
token68 = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" ) token68 = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" )
*"=" *"="
Appendix D. Change Log
This section is to be removed before publishing as an RFC.
D.1. Since RFC 7235
The changes in this draft are purely editorial:
o Change boilerplate and abstract to indicate the "draft" status,
and update references to ancestor specifications.
o Remove version "1.1" from document title, indicating that this
specification applies to all HTTP versions.
o Adjust historical notes.
o Update links to sibling specifications.
o Replace sections listing changes from RFC 2617 by new empty
sections referring to RFC 723x.
o Remove acknowledgements specific to RFC 723x.
o Move "Acknowledgements" to the very end and make them unnumbered.
Index Index
4 4
401 Unauthorized (status code) 6 401 Unauthorized (status code) 7
407 Proxy Authentication Required (status code) 6 407 Proxy Authentication Required (status code) 7
A A
Authorization header field 8 Authorization header field 8
C C
Canonical Root URI 5 Canonical Root URI 6
G G
Grammar Grammar
auth-param 4 auth-param 4
auth-scheme 4 auth-scheme 4
Authorization 8 Authorization 8
challenge 4 challenge 5
credentials 5 credentials 5
Proxy-Authenticate 8 Proxy-Authenticate 9
Proxy-Authorization 9 Proxy-Authorization 9
token68 4 token68 4
WWW-Authenticate 7 WWW-Authenticate 7
P P
Protection Space 5 Protection Space 6
Proxy-Authenticate header field 8 Proxy-Authenticate header field 9
Proxy-Authorization header field 9 Proxy-Authorization header field 9
R R
Realm 5 Realm 6
W W
WWW-Authenticate header field 7 WWW-Authenticate header field 7
Acknowledgments
The previous specification took over the definition of the HTTP
Authentication Framework, previously defined in RFC 2617. We thank
John Franks, Phillip M. Hallam-Baker, Jeffery L. Hostetler, Scott
D. Lawrence, Paul J. Leach, Ari Luotonen, and Lawrence C. Stewart
for their work on that specification. See Section 6 of [RFC2617] for
further acknowledgements.
See Appendix "Acknowledgments" of [MESSGNG] for the Acknowledgments
related to this document revision.
Authors' Addresses Authors' Addresses
Roy T. Fielding (editor) Roy T. Fielding (editor)
Adobe Systems Incorporated Adobe
345 Park Ave 345 Park Ave
San Jose, CA 95110 San Jose, CA 95110
USA USA
EMail: fielding@gbiv.com EMail: fielding@gbiv.com
URI: http://roy.gbiv.com/ URI: http://roy.gbiv.com/
Mark Nottingham (editor)
Fastly
EMail: mnot@mnot.net
URI: https://www.mnot.net/
Julian F. Reschke (editor) Julian F. Reschke (editor)
greenbytes GmbH greenbytes GmbH
Hafenweg 16 Hafenweg 16
Muenster, NW 48155 Muenster, NW 48155
Germany Germany
EMail: julian.reschke@greenbytes.de EMail: julian.reschke@greenbytes.de
URI: http://greenbytes.de/tech/webdav/ URI: http://greenbytes.de/tech/webdav/
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