^{The company creates programs for sale, re-sale, and out in the Open Source
world. The company can be contracted for the creation, installation, configuration,
and modification of applications.}

^{More information can be found at http://www.amduus.com
or sales@amduus.com.}

^Introduction

^{There will be times when you need to share source code without wanting
to share the code. This is because .r files need to be recompiled from source
when those files use a database table that has changed.}

^{This program is a cheap and easy means of accomplishing that. It uses
a combination of two somewhat well known encryption methods.}

^{Note that this program keeps honest people honest. The algorithm is based
on a block cipher and block ciphers can have cryptanalysis performed on them.
But it is safe enough to be a nuisance to people who might want a peek at source
code released out into the “wild.”}

^{In general, it works like this:}

^{The reason this program was written was to release code into the wilds
of the internet, where by some of the program was open source and could be modified
by the user, and other parts remain proprietary so that the user would need
to contract with Amduus Information Works, Inc. to make changes.}

^{Determining the version of your encryptor:}

^{There are different versions of encryptor available. This document is
written for version named on the title page. The versions previous to version
1.4 are not backwards compatible, so knowing the version you are working with
is important.}

^{Encryptor is written using the RCS[1] source code control system. By entering the following
command, you will be able to determine your version number (in bold):}

[/appl/encrypt]$ ident encryptit.p

encryptit.p:

$Header: /home/appl/encrypt/RCS/encryptit.p,v 1.4 2001/11/06 18:48:07 sauge Exp sauge $

^{Installing the package}

^{The distribution file is a zip file named dist3.zip. This file should
be downloaded from the Open Source area of Amduus Information Works, Inc. at
http://www.amduus.com.}

^{Follow these steps:}

^{Create a directory for the encrption software to be placed in}
^{Copy the distribution file to that directory}
^{Execute the command unzip [distribution_file_name]}
^{Configure the cmpencrypt.bash script (see below)}
^{Create a file directory structure that will hold the encrypted versions
of your source}

^{Configuring the encryption compiler}

^{Compiling an encrypted program produces a .r file which is in sync with
the definition of the database tables it uses. In order for the creation of
the .r file, the compile program needs to have access to the database the compiled
source is to run against.}

^{Note: You cannot run this program on a query/run
time license – you must have Provision or the 4GL Development system installed
and in use. You CAN run the resulting .r on a run-time version of the progress
client however.}

^{This is done in the normal Progress fashion by using the –pf argument on the
command line invocation of the progress executable.}

# Compile an encrypted program

if [ -z "$1" ]; then

echo cmpencrypt.bash [filename] [passphrase]

exit 0

export FILENAME=$1

export PASSPHRASE=$2

$DLC/bin/_progres -b -p cmpencrypt.p –pf Your_PF_File

# $Header: /home/appl/encrypt/RCS/cmpencrypt.bash,v 1.2 2001/11/06 00:22:21 sauge Exp sauge $

^{It is assumed the Progress oriented variables are already available in
the shell invoking the command.}

^{Performing an encryption}

^{Limitations of what can be encrypted}

^{Only .p and .w files can be compiled. It is based on the limitations
of the COMPILE statement – hence, include files cannot be compiled in encrypted
form. Hopefully this limitation will be eliminated in the next version.}

^{The encryption command does not encrypt the original source file. It
creates an encrypted copy in a different directory. You should never encrypt
the same file in the same directory. There is no convenient way back.}

^{The encryption command script}

^{Typing the command without any arguments will provide an argument list
for easy reference of how the command should be invoked.}

[/appl/encrypt]$ encryptit.bash

encryptit.bash [filename] [output_directory] [passphrase]

^{An example invocation:}

[/appl/encrypt]$ encryptit.bash cmpencrypt.p dist gfdthe4563d

^{This call takes the cmpencrypt.p file in the current working directory,
encrypts it with the pass phrase gfdthe4563d and places an encrypted copy in
the dist sub-directory. Absolute directory paths, etc. can be used safely.}

^{Note: The encryption program does not compile
against any databases, so it does not need a database connection. The .r that
comes with the package is for Version 9 of Progress and should work on query
run-time licenses.}

^{Performing a compile of an encrypted file}

^{Before compiling any encrypted files that manipulate database tables,
be sure to have the encryption script configured to speak with the database
server.}

^{Typing the command without any arguments will provide an argument list
for easy reference of how the command should be invoked.}

[/appl/encrypt]$ cmpencrypt.bash

cmpencrypt.bash [filename] [passphrase]

^{An example invocation:}

[/appl/encrypt]$ cmpencrypt.bash dist/cmpencrypt.p gfdthe4563d

^{This example invocation compiles the file dist/cmpencrypt.p with the pass
phrase of}gfdthe4563d. The resulting .r file will be placed in the same directory as the encrypted source file.

^{In order to compile an encrypted program, you must have the pass phrase
used to encrypt the program.}

^Glossary

^{Additional References:}

^{Bruce Schneier, Applied Cryptography 2nd Edition, ISBN 0-471-12845-7}

^{Neal Koblitz, Algebraic Aspects of Cryptography, ISBN 3-540-63446-0}

^{Wayne Patterson, Mathematical Cryptology, ISBN 0-8476-7438-X}

[1]^{CVS is based on RCS tags, so it
should work also.}

^{About Amduus Information Works, Inc.}

^Introduction

^{Determining the version of your encryptor:}

^{Installing the package}

^{Configuring the encryption compiler}

^{Performing an encryption}

^{Limitations of what can be encrypted}

^{The encryption command script}

^{Performing a compile of an encrypted file}

^Glossary

^{Cipher Text}

^{Cryptoanalysis}

^{Cryptoanalyst}

^Cryptosystem

^Decrypt

^Encrypt

^{Plain Text}

^{Additional References:}