I’m working on a C# project and need some help with external libraries.
I have this situation where there’s a third-party application installed on my machine that comes with its own DLL file. I want to write C# code that can interact with this software through its DLL, but I’m not sure how to figure out what functions are available for me to call.
The DLL isn’t part of the Windows system libraries, so I can’t just look up documentation online easily. Is there a way to inspect or analyze the DLL file to see what methods or functions it exports? What tools or techniques should I use to discover the API endpoints I can work with?
Any guidance on the best approach to reverse engineer or examine these external DLL files would be really helpful.
Try IDA Free or Ghidra for deeper analysis. These disassemblers show you the actual assembly code and catch function signatures that basic export viewers miss. I use this all the time with DLLs that have bare-bones or obfuscated export tables. Also run the original app under API Monitor - it captures every API call and shows exactly how the DLL functions get called with real parameters. You’ll see actual usage patterns instead of just function names. Remember some DLLs use callbacks or need specific startup sequences, so watching how the original software behaves beats just having the exported function list.
run process monitor alongside the app - it shows which dll functions get called in real time. saved my butt when i hit the same wall last year. you’ll see actual function calls and the params they’re passing.
Dependency Walker is a reliable tool I’ve used for examining DLLs. It provides a comprehensive view of all exported functions along with their calling conventions. Simply dragging the target DLL file into the application reveals its entire function list. Alternatively, if you have Visual Studio, the command line tool dumpbin.exe can be utilized by executing “dumpbin /exports yourfile.dll” in the developer command prompt; this will give you a detailed export list with ordinal numbers. However, keep in mind that identifying the function names is just the beginning. Understanding the parameter types and conventions may require some experimentation or insight from existing applications that interact with the DLL.