DotNetFringe presentation about .NET assemblies. Abstract: If there's a fringe practice with .NET, it's opening the hood of the .NET binaries, aka assemblies, and tinkering directly with the metadata and the IL bytecode. Interested in compilers? Profilers? IDEs? Virtual Machines? Developer tools in general? On .NET, all of those share a common form of data: assemblies. What better way is there to learn more about the platform than by manipulating its data? While it’s sometimes viewed as some form of black magic, it’s really no rocket science. This session will be the opportunity for .NET developers to learn how to analyze and manipulate the very data they consume and produce every day, and how to pick the right tool for the job.

1. Jb Evain
@jbevain
Visual Studio
Platform Team
Mono contributor

2. Visual Studio Tools for Unity

3. The most important file
format…

4. … for .NET developers

5. You consume it

6. You produce it

7. A binary format

8. the .NET assembly

10. .NET assembly
=
Windows executable

12. Why should you care
¯_(ツ)_/¯

13. Chapter 1
The data

14. PE file
HEADERS
SECTION
SECTION

15. .NET metadata
HEADERS
Strings
Types MethodsFields Parameters …
Blobs GuidsHeaps
Tables

17. .NET metadata
void Foo::Bar(int i)
Strings
Foo
Bar
i
Type
#1
Method
#1
Parameter
#1
Blobs
instance void(int)
Heaps
Tables

19. .NET IL
Tables
Heaps
IL

20. Chapter 2
The tools

21. using System.Reflection;

22. Not great for
 Reading assemblies as data
 Reading IL code
 Modifying assemblies

23. 1. IKVM.Reflection

24. Great for
 Creating new assemblies
 Porting System.Reflection code

25. 2. System.Reflection.Metadata

26. Great for
 Reading metadata (very) quickly

27. 3. Mono.Cecil

28. Great for
 Analyzing assemblies
 Modifying assemblies

29. Thank you!
@jbevain