Security Negotiation for WebNFS
RFC 2755
| Document | Type |
RFC - Informational
(January 2000; No errata)
Was draft-chiu-network-wnfs-sec-nego (individual)
|
|
|---|---|---|---|
| Last updated | 2013-03-02 | ||
| Stream | Legacy | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Stream | Legacy state | (None) | |
| Consensus Boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | RFC 2755 (Informational) | |
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Network Working Group A. Chiu
Request for Comments: 2755 M. Eisler
Category: Informational B. Callaghan
Sun Microsystems
January 2000
Security Negotiation for WebNFS
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2000). All Rights Reserved.
Abstract
This document describes a protocol for a WebNFS client [RFC2054] to
negotiate the desired security mechanism with a WebNFS server
[RFC2055] before the WebNFS client falls back to the MOUNT v3
protocol [RFC1813]. This document is provided so that people can
write compatible implementations.
Table of Contents
1. Introduction .............................................. 2
2. Security Negotiation Multi-component LOOKUP ............... 3
3 Overloaded Filehandle ..................................... 4
3.1 Overloaded NFS Version 2 Filehandle ..................... 5
3.2 Overloaded NFS Version 3 Filehandle ..................... 6
4. WebNFS Security Negotiation ............................... 6
5. Security Considerations ................................... 10
6. References ................................................ 10
7. Acknowledgements .......................................... 10
8. Authors' Addresses ........................................ 11
9. Full Copyright Statement .................................. 12
Chiu, et al. Informational [Page 1]
RFC 2755 Security Negotiation for WebNFS January 2000
1. Introduction
The MOUNT protocol is used by an NFS client to obtain the necessary
filehandle for data access. MOUNT versions 1 and 2 [RFC1094] return
NFS version 2 filehandles, whereas MOUNT version 3 [RFC1813] returns
NFS version 3 filehandles.
Among the existing versions of the MOUNT protocol, only the MOUNT v3
provides an RPC procedure (MOUNTPROC3_MNT) which facilitates security
negotiation between an NFS v3 client and an NSF v3 server. When this
RPC procedure succeeds (MNT3_OK) the server returns to the client an
array of security mechanisms it supports for the specified pathname,
in addition to an NFS v3 filehandle.
A security mechanism referred to in this document is a generalized
security flavor which can be an RPC authentication flavor [RFC1831]
or a security flavor referred to in the RPCSEC_GSS protocol
[RFC2203]. A security mechanism is represented as a four-octet
integer.
No RPC procedures are available for security negotiation in versions
1 or 2 of the MOUNT protocol.
The NFS mount command provides a "sec=" option for an NFS client to
specify the desired security mechanism to use for NFS transactions.
If this mount option is not specified, the default action is to use
the default security mechanism over NFS v2 mounts, or to negotiate a
security mechanism via the MOUNTPROC3_MNT procedure of MOUNT v3 and
use it over NFS v3 mounts. In the latter, the client picks the first
security mechanism in the array returned from the server that is also
supported on the client.
As specified in RFC 2054, a WebNFS client first assumes that the
server supports WebNFS and uses the publsc filehandle as the initial
filehandle for data access, eliminating the need for the MOUNT
protocol. The WebNFS client falls back to MOUNT if the server does
not support WebNFS.
Since a WebNFS client does not use MOUNT initially, the
MOUNTPROC3_MNT procedure of MOUNT v3 is not available for security
negotiation until the WebNFS client falls back to MOUNT. A viable
protocol needs to be devised for the WebNFS client to negotiate
security mechanisms with the server in the absence of the
MOUNTPROC3_MNT procedure.
Chiu, et al. Informational [Page 2]
RFC 2755 Security Negotiation for WebNFS January 2000
The WebNFS security negotiation protocol must meet the following
requirements:
- Must work seamlessly with NFS v2 and v3, and the WebNFS
protocols
- Must be backward compatible with servers that do not support
this negotiation
- Minimum number of network turnarounds (latency)
This document describes the WebNFS security negotiation protocol
developed by Sun Microsystems, Inc. Terminology and definitions from
RFCs 2054 and 2055 are used in this document. The reader is expected
to be familiar with them.
2. Security Negotiation Multi-component LOOKUP
The goal of the WebNFS security negotiation is to allow a WebNFS
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