diff options
Diffstat (limited to 'third_party/heimdal/doc/standardisation/draft-brezak-spnego-http-00.txt')
-rw-r--r-- | third_party/heimdal/doc/standardisation/draft-brezak-spnego-http-00.txt | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/third_party/heimdal/doc/standardisation/draft-brezak-spnego-http-00.txt b/third_party/heimdal/doc/standardisation/draft-brezak-spnego-http-00.txt new file mode 100644 index 00000000000..96f157a5f13 --- /dev/null +++ b/third_party/heimdal/doc/standardisation/draft-brezak-spnego-http-00.txt @@ -0,0 +1,395 @@ + + +Kerberos working group J.Brezak +Internet Draft Microsoft +Document: draft-brezak-spnego-http-00.txt +Category: Informational + September 2001 + + + HTTP Authentication: SPNEGO Access Authentication + + +Status of this Memo + + This document is an Internet-Draft and is in full conformance with + all provisions of Section 10 of RFC2026 [1]. Internet-Drafts are + working documents of the Internet Engineering Task Force (IETF), its + areas, and its working groups. Note that other groups may also + distribute working documents as Internet-Drafts. Internet-Drafts are + draft documents valid for a maximum of six months and may be + updated, replaced, or obsoleted by other documents at any time. It + is inappropriate to use Internet- Drafts as reference material or to + cite them other than as "work in progress." + + The list of current Internet-Drafts can be accessed at + http://www.ietf.org/ietf/1id-abstracts.txt + + The list of Internet-Draft Shadow Directories can be accessed at + http://www.ietf.org/shadow.html. + +1. Abstract + + This document describes how MicrosoftÆs Internet Explorer 5.0 and + Internet Information Services 5.0 use Kerberos for security + enhancements of web transactions. The HTTP auth-scheme of + 'negotiate' is defined here; when the negotiation results in the + selection of Kerberos, the security services of authentication and + optionally impersonation are performed. + + +2. Conventions used in this document + + In examples, "C:" and "S:" indicate lines sent by the client and + server respectively. + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in + this document are to be interpreted as described in RFC-2119 [3]. + + +3. Access Authentication + +3.1 Reliance on the HTTP/1.1 Specification + + This specification is a companion to the HTTP/1.1 specification [4] + and builds on the authentication mechanisms defined in [5]. It uses + +Brezak Category û Informational 1 + + + + + + + + + SPNEGO Access Authentication September 2001 + + the augmented BNF section 2.1 of that document, and relies on both + the non-terminals defined in that document and other aspects of the + HTTP/1.1 specification. + + +4. HTTP Negotiate Authentication Scheme + + Use of Kerberos is wrapped in an HTTP auth-scheme of "Negotiate". + The auth-params exchanged use data formats defined for use with the + GSS-API [6]. In particular, they follow the formats set for the + SPNEGO [7] and Kerberos [8] "mechanisms" for GSSAPI. The + "Negotiate" auth-scheme calls for the use of SPNEGO GSSAPI tokens + which the specific mechanism type specifies. + +4.1 The WWW-Authenticate Response Header + + If the server receives a request for an access-protected object, and + an acceptable Authorization header is not sent, the server responds + with a "401 Unauthorized" status code, and a WWW-Authenticate header + as per the framework described in [4]. The negotiate scheme will + operate as follows: + + + challenge = "Negotiate" auth-data + auth-data = 1#( [gssapi-data] ) + + The meanings of the values of the directives used above are as + follows: + + gssapi-data + If the gss_accept_security_context return a token for the + client, this directive contains is the base64 encoding of an + InitialContextToken as defined in [6]. + + A status code 200 response can also carry a WWW-Authenticate + response header containing the final leg of a authentication. Before + using the contents of the response, the gssapi-data should be + processed by gss_init_security_context to determine the state of the + security context. If this function indicates success, the response + can be used by the application. Otherwise an appropriate action + based on the authentication status should be. + + For example the authentication could have failed on the final leg if + mutual authentication was requested and the server was not able to + prove its identity. In this case, the returned results are suspect. + It is not always possible to mutually authenticate the server before + the HTTP operation. POST methods are in this category. + + When the Kerberos Version 5 GSSAPI mechanism [RFC-1964] is being + used, the HTTP server will be using a principal name of the form of + "http/<hostname>". + +4.2 The Authorization Request Header + + +Brezak Category û Informational 2 + + + + + + + + + SPNEGO Access Authentication September 2001 + + The client is expected to retry the request, passing an + Authorization header line, which is defined according to the + framework described in [4] utilized as follow: + + credentials = "Negotiate" auth-data2 + auth-data2 = 1#( gssapi-data ) + + gssapi-data + This directive contains is the base64 encoding of an + InitialContextToken as defined in [6]. + + If a directive or its value is improper, or required directives are + missing, the propose response is 400 Bad Request. If a 401 + Unauthorized status code is returned, the contents of the WWW- + Authenticate response header is used to continue the authentication + as long as the opaque value is the same. + +5. Negotiate Operation Example + + The user is logged onto realm A.COM as user@A.COM. The web server is + in realm B using the principal http/server@B.COM. Realm B.COM trusts + Realm A.COM + + The client requests an access-protected document from server via a + GET method request. The URI of the document is + "http://www.nowhere.org/dir/index.html". + + The first time the client requests the document, no Authorization + header is sent, so the server responds with: + + HTTP/1.1 401 Unauthorized + WWW-Authenticate: Negotiate + + The client will obtain the user credentials using the SPNEGO GSSAPI + mechanism type to identify generate a GSSAPI message to be sent to + the server with a new request, including the following Authorization + header: + + Authorization: Negotiate + 2a87421000492ade0234568ac0289eca874209af8bc028 + + The server will decode the gssapi-data and pass this to the SPNEGO + GSSAPI mechanism in the gss_accept_security_context function. The + return value from the gss_accept_security_context function can + indicate the security context is complete and supply final + authentication data to be returned to the client. If the server has + more gssapi data to send to the client to complete the context it is + to be carried in WWW-Authenticate header with the final response. + The response will be sent to the client, including the following + header: + + HTTP/1.1 200 Success + WWW-Authenticate: Negotiate ade0234568ac874209af8bc0280289eca + + +Brezak Category û Informational 3 + + + + + + + + + SPNEGO Access Authentication September 2001 + + The client will decode the gssapi-data and supply it to + gss_init_security_context using the context for this server. If the + status is successful from the final gss_init_security_context, the + response can be used by the application. + +7. Security Considerations + + The SPNEGO HTTP authentication facility is only used to provide + authentication of a user to server. It provides no facilities for + protecting the HTTP headers or data including the Authorization and + WWW-Authenticate headers that are used to implement this mechanism. + + This mechanism is not used for HTTP authentication to HTTP proxies. + + If an HTTP proxy is used between the client and server, it must take + care to not share authenticated connections between different + authenticated clients to the same server. If this is not honored, + then the server can easily lose track of security context + associations. A proxy that correctly honors client to server + authentication integrity will supply the "Proxy-support: Session- + Based-Authentication" HTTP header to the client in HTTP responses + from the proxy. The client MUST NOT utilize the SPNEGO HTTP + authentication mechanism through a proxy unless the proxy supplies + this header with the 401 Unauthorized response from the server. + + +8. References + + + 1 Bradner, S., "The Internet Standards Process -- Revision 3", BCP + 9, RFC 2026, October 1996. + + 3 Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997 + + 4 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. + + 5 Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., Leach, + P., Luotonen, A., Stewart, L., "HTTP Authentication: Basic and + Digest Access Authentication", RFC 2617, June 1999. + + 6 Linn, J., "Generic Security Service Application Program Interface, + Version 2", RFC 2078, January 1997. + + 7 Baize, E., Pinkas, D., "The Simple and Protected GSS-API + Negotiation Mechanism", RFC 2478, December 1998. + + 8 Linn, J., "The Kerberos Version 5 GSS-API Mechanism", RFC 1964, + June 1996. + + + + +Brezak Category û Informational 4 + + + + + + + + + SPNEGO Access Authentication September 2001 + + +10. Author's Addresses + + John Brezak + Microsoft + One Microsoft Way + Redmond, Washington + Email: jbrezak@microsoft.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Brezak Category û Informational 5 + + + + + + + + + SPNEGO Access Authentication September 2001 + + +Full Copyright Statement + + Copyright (C) The Internet Society (2001). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph + are included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE." + + + + + + + + + + + + + + + + + + + + + + + + + + + +Brezak Category û Informational 6 + + + + + + + |