C# Decompilers? [closed]

by

It’s mostly true. A very clever programmer named Lutz Roeder wrote an excellent decompiler named Reflector (now owned by redgate). It’s quite good at translating IL back to either C# or VB.NET code. It isn’t complete magic, it cannot

  • translate constants back to their constant identifier
  • recover the names of local variables
  • decompile anonymous methods except in their intermediate form
  • decompile iterators, as above
  • decompile lambdas, as above
  • decompile the code that uses the promised C# 5 async and await keywords, as above
  • recover the comments in your code.

And has a few bugs that makes it resort to goto statements or fall over. It is otherwise very useful as a debugging aid, helping you discover and diagnose bugs in code you didn’t write. There are no documented cases of anyone using it to start a successful business from pirated source code obtained through decompilation. It works too well for that.

It has otherwise started a lively market segment for ‘obfuscators’, tools that rewrite the contents of an assembly to make it hard to decompile it. Typical strategies are to rewrite identifiers so they become very hard to interpret and/or to tinker with the structure of the assembly so a decompiler will crash but the CLR will not. Redgate, the current owner of Reflector, also sells an obfuscator. There is one included with Visual Studio paid licenses, called ‘Dotfuscator Community Edition’. No idea how good it is, this never gets put to the test.

Just using lots of lambdas and iterators in your code is already an excellent way to obfuscate your code. Reverse-engineering it to the original code is very difficult. That Lutz gave up on Reflector at the exact same time he did is not a coincidence, that’s when C# became too hard to decompile reliably.

More Related Contents:

  1. How to enable assembly bind failure logging (Fusion) in .NET
  2. How do I abort/cancel TPL Tasks?
  3. Fire and forget async method in asp.net mvc
  4. Editing dictionary values in a foreach loop
  5. How to use the ternary operator inside an interpolated string?
  6. ReadOnlyCollection or IEnumerable for exposing member collections?
  7. Static Generic Class as Dictionary
  8. SqlConnection SqlCommand SqlDataReader IDisposable
  9. Extension methods syntax vs query syntax
  10. Refactoring code to avoid anti-pattern
  11. DateTime ToString issue with formatting months with “mm” specifier
  12. How do I create an expression tree calling IEnumerable.Any(…)?
  13. Is the sorting algorithm used by .NET’s `Array.Sort()` method a stable algorithm?
  14. OracleParameter and IN Clause
  15. Upload file on FTP
  16. What is the performance of the Last() extension method for List?
  17. How can I merge two JObject? [duplicate]
  18. Json.NET adding backslash while returning json serialized string
  19. How to set DataGridView textbox column to multi-line?
  20. Locking pattern for proper use of .NET MemoryCache
  21. Using PerformanceCounter to track memory and CPU usage per process?
  22. Passing datatable to a stored procedure
  23. How to force LINQ Sum() to return 0 while source collection is empty
  24. When to use pointers in C#/.NET?
  25. Static Linking of libraries created on C# .NET
  26. Given full path, check if path is subdirectory of some other path, or otherwise
  27. What’s the best way to watchdog a desktop application?
  28. How to replace the text between two characters in c#
  29. get barcode reader value form background monitoring
  30. How to modify my App.exe.config keys at runtime?

Leave a Comment