🚀 go-pugleaf

Charl Gerber (gerber@stb.dfs.co.za) wrote:
: I am looking for some documentation (preferable a www site) which describes
: some good methods of copy right protection in software. If possible, Modula
: 2 source code or libraries would even be better. Please send e-mail if you
: can help me.

I don't know if this is what you're looking for but I have a C library (no
source) that allows you to check the CRC and file length inside the program.
This is one way to check for reverse engineering and tampering (someone
disassembles the program to by-pass password/copy protection.)  It involves
calling a function at the beginning of the program that reads a section of the
executable with a stored CRC and file length.  It then calculates the CRC
of the executable and checks the file length with the stored values and reports
the results.  Then you add code to react on the results, ie. terminate the
program if they don't match exactly.  
This is very simple but using the C libraries with Modula-2 could be a 
problem, depending on what compiler you have.

Jeff

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