youngshingjun / swiftdump

SwiftDump is a command-line tool for retriving the Swift Object info from Mach-O file.

SwiftDump

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SwiftDump is a command-line tool for retriving the Swift Object info from Mach-O file. Similar to class-dump, but the difference is that SwiftDump focus on swift 5 objects. For Mach-O files mixed with Objective-C and swift, you can combine class-dump with SwiftDump.

There is alos a Frida version named FridaSwiftDump.

You can either useSwiftDump for a Mach-O file or FridaSwiftDump for a foreground running app.

If you are curious about the Mach-O format, check the image at the bottom of this article.

Usage

USAGE: SwiftDump [--debug] [--arch <arch>] <file> [--version]

ARGUMENTS:
  <file>                  MachO File

OPTIONS:
  -d, --debug             Show debug log.
  -a, --arch <arch>       Choose architecture from a fat binary (only support x86_64/arm64).
                          (default: arm64)
  -v, --version           Version
  -h, --help              Show help information.

• SwiftDump ./TestMachO > result.txt
• SwiftDump -a x86_64 ./TestMachO > result.txt

Features

• Written entirely in swift, the project is tiny
• Dump swift 5 struct/class/enum/protocol
• Parse enum with payload case
• Support inheritance and protocol
• Since it is written in swift, the mangled names are demangled by swift's runtime function, such as swift_getTypeByMangledNameInContext and swift_demangle_getDemangledName.

Thanks to the runtime function, SwiftDump can demangle complex type, such as RxSwift variable. For example, RxSwift.Queue<(eventTime: Foundation.Date, event: RxSwift.Event<A.RxSwift.ObserverType.Element>)>

TODO

• Parse swift function address
• More

Compile

1. Clone the repo
2. Open SwiftDump.xcodeproj with Xcode
3. Modify 'Signing & Capabilities' to use your own id
4. Build & Run

The default Mach-O file path is Demo/test, you can change it in Xcode - Product - Scheme - Edit Scheme - Arguments

(Tested on Xcode Version 11.5 (11E608c), MacOS 10.15.5)

Credit

• Machismo : Parsing of Mach-O binaries using swift.
• swift-argument-parser : Straightforward, type-safe argument parsing for Swift.
• Swift metadata : High level description of all the Swift 5 sections that can show up in a Swift binary.

License

MIT

Mach-O File Format

The following image shows how SwiftDump parse swift types from file Demo/test. You can open this file with MachOView.