system, it is recommended that the FTP-Initiated service and FTAM-
Initiated gateway listener processes be merged into a single
executable module. This single daemon will act as the one and only
gateway listener processes. As connections were established with
hosts, other processes would be created.
10.4. Implementation Testing
To assist in the development and evaluation of FTP-FTAM gateway
prototypes, NIST has developed a test system to evaluate a gateway's
conformance to the protocol standards [NIST88].
10.5. POSIX File Naming and Organization
The OSI profiles do not define a standard manner for an FTAM
Responder to return file names.
To avoid unnecessary complexity, proprietary file systems are not
addressed in these mappings. Gateway support for POSIX file naming
and organization conventions is required; i.e., files are assumed to
be organized in a hierarchical structure in which all of the non-
terminal nodes are directories and all of the terminal nodes are any
other type of file.
11. Security Considerations
The gateway system may place the burden of authentication on the
destination system. However, the gateway must accommodate the
passing through of all authentication parameters. The authentication
parameters of each protocol are applied at the destination and no
additional parameters are needed for authentication at the gateway.
As such, no gateway password file is required to support gateway
functions.
It is anticipated that the requirement for a strong authentication
mechanism will soon replace the most currently used, userid and
password mechanism. The U.S. National Security Agency (NSA) has
already prototyped and has plans field a Message Secure Protocol
(MSP) as part of the Defense Message System (DMS) Program which will
soon become the Department of Defense (DoD) mandatory messaging
system. MSP utilizes a public key encryption-like mechanism which
will be used to authenticate users and allow signed operations. The
current philosophy is to use this same mechanism for all
authentication and access control situations, such as logging onto
remote hosts or gateways. Detailed specifications for Pre-MSP, used
in the unclassified though sensitive arena, are scheduled to be
published in the first quarter of 1993. The requirement for gateways
to process PMSP and MSP strong authentication mechanisms will be part
of all future DoD procurements.
12. References
[ISO8571-1] Information processing systems - Open Systems
Interconnection - File Transfer, Access and
Management, Part 1: General Introduction, International
Standards Organization for Standards, First Edition,
October 1988.
[ISO8571-2] Information processing systems - Open Systems
Interconnection - File Transfer, Access and Management,
Part 2: Virtual Filestore Definition, International
Standards Organization for Standards, First Edition,
October 1988.
[ISO8571-3] Information processing systems - Open Systems
Interconnection - File Transfer, Access and Management,
Part 3: File Service Definition, International Standards
Organization for Standards, First Edition, October 1988.
[ISO8571-4] Information processing systems - Open Systems
Interconnection - File Transfer, Access and Management,
Part 4: File Protocol Specification, International
Standards Organization for Standards, First Edition,
October 1988.
[ISO8571-5] Information processing systems - Open Systems
Interconnection - File Transfer, Access and Management,
Part 5: Protocol Implementation Conformance Statement,
International Standards Organization for Standards,
First Edition.
[KILLE92] Hardcastle-Kille, S., "Using the OSI Directory to achieve
User Friendly Naming", OSI-DS 24 (v1.1), October 1992.
[MITRE87] Scott, J., "An FTP/FTAM Application Bridge, An FTAM/FTAM
(MTR-87W00186)", The MITRE Corporation, July 1987.
[NETWRX90a] Mindel, J., "Gateway Technical Specification" Open
Networks, Inc. (formerly NetWorks One), 28 February 1990.
[NETWRX90b] Mindel, J., "FTP Gateway User's Guide", Open
Networks, Inc. (formerly NetWorks One), 28 February 1990.
[NIST86] Wallace, M, et. al., "A Gateway Architecture Between FTP
and FTAM (ICST/SNA86-6)", National Institute of Standards
and Technology, U.S. Department of Commerce, July 1986.
[NIST88] A Test System for Implementations of FTAM/FTP Gateways:
Final Report Part 1, National Institute of Standards and
Technology, U.S. Chamber of Commerce, October 1988.
[NIST91] CSL Bulletin: File Transfer, Access, and Management,
National Institute of Standards and Technology, U.S.
Chamber of Commerce, July 1991.
[NIST92] Stable Implementation Agreements for Open Systems
Interconnection Protocols: Part 9 - FTAM Phase 2, Output
from the March 1992 Open Systems Environment Implementors'
Workshop (OIW), March 1992.
[RFC959] Postel, J., and J. Reynolds, "File Transfer Protocol
(FTP), STD 9, RFC959, USC/Information Sciences Institute,
October 1985.
[RFC1101] Mockapetris, P., "DNS Encoding of Network Names and other
Types", RFC1101, USC/Information Sciences Institute,
April 1989.
[RFC1279] Hardcastle-Kille, S., "X.500 and Domain", RFC1279,
University College London, November 1991.
[ROSE90] Rose, M., "The Open Book: A Practical Perspective on OSI",
Prentice-Hall Inc., 1990.
13. Authors' Addresses
Joshua L. Mindel
Open Networks, Inc.
11490 Commerce Park Dr., Suite 205
Reston, Virginia 22091 USA
Phone: (703) 648-0013
Email: mindel@netwrx1.nw1.com
Robert L. Slaski
Open Networks, Inc.
11490 Commerce Park Dr., Suite 205
Reston, Virginia 22091 USA
Phone: (703) 648-0013
Email: slaski@netwrx1.nw1.com