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II.
BACKGROUND
This chapter provides background information relating to this project. The first
section discusses the MYSEA project, and provides an overview of OpenSSH including
its history, available clients, available authentication methods and its modes of operation.
The second section provides information about the port of OpenSSH to the XTS-400.
Within this section, features used by OpenSSH but have a different behavior on the XTS400 are discussed. Then, the way the XTS-400 handles those features is discussed along
with a brief description of security policies available on the XTS-400. The last section
will cover the software dependencies of OpenSSH.
A.
ARCHITECTURAL BACKGROUND
1.
MYSEA Project
“[MYSEA] provides a trusted distributed operating environment for enforcing
multilevel security policies, and utilization of support for incorporation of unmodified
commodity productivity applications for user activities” [IRV04]. This means that the
MYSEA project uses a client-server architecture where the server, called the MYSEA
server, is responsible for the enforcement of security policies. This server is one of the
very few specialized hardware components required by MYSEA. The other specialized
hardware components are the Trusted Path Extensions (TPE) and the Trusted Channel
Modules (TCM). The TPE is a device that will provide an unforgeable communications
link between the server and the client machine.
The TCMs authenticate network
sensitivity levels to the MYSEA server so that the information received from that
network may be labeled correctly.
writeable storage.
The clients are intended to have no permanent
A Knoppix client as well as a specialized version of Microsoft
Windows XP Embedded called “state-less professional” are part of the design. The use of
a popular operating system such as Microsoft Windows supports user acceptance because
users may continue to use their favorite, and familiar, office productivity applications.
The MYSEA server uses an XTS-400 as its base. It will be discussed in a future section.
The XTS-400 provides an unforgeable communications link called a “trusted
path” between the target of evaluation (TOE) security functions (TSF) and the user. The
TSF is “a set consisting of all hardware, software, and firmware of the TOE that must be
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