Take the compiler and run with it: a quick story of Swift obfuscator

Imagine a group of people with no background in the compilers nor C++.
Imagine them coming across a wonderful open source project, such as the Swift compiler.
What could happen if they started playing with it? Hacking, adding changes left and right, taking parts and making them work the way they were never intended?
Surely, the output would be some gibberish without meaning!
This story really happened. Come to listen how and why. Sometimes the gibberish is exactly what you need.

Transcript

1. Take the compiler and run with it A quick story of Swift obfuscator Krzysztof Siejkowski, @_siejkowski
3. In software development, obfuscation is the deliberate act of creating source or machine code that is difficult for humans to understand — Wikipedia
8. @objc NSObject
10. Source code Binary Compilation Attacker Obfuscation
11. Source code Obfuscated binary Compilation Attacker Obfuscation Example: iXGuard by GuardSquare
12. Source code Obfuscated
 binary Obfuscating
 Compilation Attacker Obfuscation Example: Obfuscator-LLVM
13. Obfuscated source code Obfuscated binary Compilation Attacker Obfuscation Example: ???
16. Obfuscated source code Obfuscated binary Compilation Attacker Obfuscation Example: WE
17. Source code Parse Find symbols Analyze symbols Obfuscated source code Rename
18. Compiler ✨
25. Swift compiler 
 as a library?
26. swiftParse swiftDriver swiftAST swiftSyntax swiftBasic
27. swiftParse swiftDriver swiftAST swiftSyntax swiftBasic
28. swiftParse swiftDriver swiftAST swiftSyntax swiftBasic swift swift-syntax- test swift-refactor
29. swiftParse swiftDriver swiftAST swiftSyntax swiftBasic swift swift-syntax- test swift-refactor
30. swiftParse swiftDriver swiftAST swiftSyntax swiftBasic swiftObfuscation obfuscator-renamer obfuscator-symbol- extractor
33. Source code MAGIC
 % Analyzed 
 source code
34. swiftFrontend Source code CompilerInstance. performSema() Analyzed 
 source code
36. swiftAST Analyzed 
 source code SourceFileWalker Symbols
 with locations
37. Symbols 
 with locations MAGIC % Obfuscated source files
38. swiftIDE Symbols 
 with locations SourceEngine & SourceManager Obfuscated source files
41. Supports Not supports
42. Supports Not supports DSYM file generation Multiple targets Some exotic Swift constructs
43. Supports Not supports Renames in Storyboards and XIBs DSYM file generation Excluding configuration Multiple targets Simple integration (local & CI) Some exotic Swift constructs
44. Open source github.com/Polidea/SiriusObfuscator
46. Pros Cons Anything compiler can do, 
 you can do too!
47. Pros Cons Anything compiler can do, 
 you can do too! No stable API, 
 breaking changes any time
48. Pros Cons Anything compiler can do, 
 you can do too! No stable API, 
 breaking changes any time So many tools available!
49. Pros Cons Anything compiler can do, 
 you can do too! No stable API, 
 breaking changes any time So many tools available! Compiler libs are designed for compilation, not for your needs
50. Pros Cons Anything compiler can do, 
 you can do too! No stable API, 
 breaking changes any time So many tools available! Compiler libs are designed for compilation, not for your needs Support for both 
 Swift and Objective-C
51. Pros Cons Anything compiler can do, 
 you can do too! No stable API, 
 breaking changes any time So many tools available! Compiler libs are designed for compilation, not for your needs Support for both 
 Swift and Objective-C Might be too much to support
52. Alternatives • libSyntax • SourceKit • existing swift tools
54. github.com/Polidea/SiriusObfuscator Documentation
55. @KacperHarasim
56. Thank you! @_siejkowski