Drawbridge 1.1

Drawbridge is a copyrighted but freely distributable bridging filter.
It uses a PC with two ethernet cards to perform the filtering. It is
composed of three different tools: Filter, Filter Compiler and Filter
Manager.

This distribution is version 1.1 which fixes some bugs in the beta test
version 1.0.  Bridging was not working efficiently and the reject and
allow clauses were not working properly.

Drawbridge is available via anonymous ftp from net.tamu.edu (128.194.177.1)
in pub/security/TAMU as two packages:

drawbridge-1.1.tar.Z and drawbridge-1.1-des.tar.Z

The drawbridge-1.1.tar.Z package is the Drawbridge base package without 
DES support.  The drawbridge-1.1-des.tar.Z package is a supplemental
package that contains the DES support. This package is installed in
addition to the drawbridge-1.1.tar.Z package; just extract it on top of
the regular package. This will add a few source files and new makefiles
to the filter and fm directories. Note that the DES package is NOT
required to operate drawbridge; it only allows you to manage drawbridge
in a secure manner.

Due to braindamaged U.S. export restrictions, only U.S. domestic sites 
will be allowed to FTP the DES package. Other sites should be able to
drop in their own favorite encryption package with little effort.
The package will function without any encryption package; this just
reduces security on filter updates across the network.

The packages should untar into 4 directories:

	doc    - directory with documentation about Drawbridge
		 (including two papers referenced in the documentation)
	fm     - directory with source code for the Filter Manager
	fc     - directory with source code for the FIlter Compiler
	filter - directory with source code for the Filter.

And 2 files:

	drawbridge.README - this file
	COPYING           - copyright notice.

The Filter Compiler and Filter Manager both require an ANSI C compiler;
the GNU C Compiler (gcc) is recommended. The Filter requires Borland's
Turbo C++ 3.0. An executable version of Filter is provided in case you
do not have access to Turbo C++.

To build Filter Compiler (fc) and Filter Manager (fm), just go into the
respective directories and type "make". This will build the
exectuables. To install fc and fm, edit the makefiles to set the
destination directory, become root and type "make install". If you have
the DES portion of the package, make sure to install that before typing
"make".

To build Filter, copy all of the filter directory to a PC and type "make".

To get a better idea of how Drawbridge works and how it is used, begin with
the OVERVIEW paper in the doc directory.

Any suggestions and comments can be sent to: drawbridge@net.tamu.edu

Drawbridge was designed and programmed by:

David K. Hess
Douglas Lee Schales
David R. Safford

Texas A&M University
July 1, 1993