digital rights management: shareware

Digital Rights Management: Shareware

Yue Wang

24 Nov 2004

Agenda

Introduction Laboratory Setup Implementation / Analysis Conclusion Reference

Introduction

Digital Rights Management is more and more important because:– More and more resources are crossing the

network– Digital resources are easier to replicate than

analogue resources

Introduction (Cont’d)

In order to improve Digital Rights Management– Understand what is current

• Nobody is telling

– Analyze what is on market

Laboratory Setup

Laptop: 2.6GHz processor, 512MB RAM, 40GB hard drive

VirtualPC– Host: Windows XP– Virtual: Windows NT 4.0 (2 identical systems

are used)

Laboratory Setup (Cont’d)

2 sharewares with licenses Disassembler and debugger

– IDA Pro– OllyDbg

Other Tools– BinText– diff on cygwin– HHD Hex Editor

Implementation / Analysis

Install 2 sharewares on both guest virtual systems, register both sharewares on one guest system

Observe files and folders, not files were modified on the registered system

Analysis (Cont’d)

Compare folders copied from both guest systems with “diff” on cygwin, no difference found

Analysis (Cont’d)

Windows registry is modified under \HKEY_LOCAL_MACHINE\SOFTWARE\

Both sharewares add their registration information into Windows registry, either by adding keys or adding fields

Registry for unregistered sharewares

Registry for registered sharewares

Registry for registered sharewares

Analysis (Cont’d)

Result from BinText

Analysis (Cont’d)

Set breakpoint and debug

Analysis (Cont’d)

The registry key is accessed by ADVAPI32.dll, which is located under C:\Windows\System32

Try different breakpoints The program starts at location 004DB302

instead of 00400000

Analysis (Cont’d)

Notes:– To add breakpoint in IDA Pro, put cursor on

the line you want to select, click Debugger -> Add Breakpoint

– To add breakpoint in OllyDbg, put cursor on the line you want to select, press F2

Reference BinText:

http://www.foundstone.com/resources/proddesc/bintext.htm

cygwin: http://www.cygwin.com/ HHD Hex Editor:

http://www.hhdsoftware.com/hexeditor.html IDA Pro: http://www.datarescue.com/idabase/ OllyDbg: http://home.t-online.de/home/Ollydbg/ VirtualPC:

http://www.microsoft.com/windows/virtualpc/default.mspx

Questions

???