# Doldrums

**Repository Path**: mark_mars/Doldrums

## Basic Information

- **Project Name**: Doldrums
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-03-04
- **Last Updated**: 2025-03-04

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

<img src="https://raw.githubusercontent.com/rscloura/Doldrums/master/logo.png" width="518" height="150">

*To flutter: to move in quick, irregular motions, to beat rapidly, to be agitated.*  
*Doldrums: a period of stagnation.*

Doldrums is a reverse engineering tool for Flutter apps targetting Android. Concretely, it is a parser and information extractor for the Flutter/Dart Android binary, conventionally named `libapp.so`, for all Dart version 2.10 releases. When run, it outputs a full dump of all classes present in the isolate snapshot.

The tool is currently in **beta**, and missing some deserialization routines and class information. If it does not work out-of-the-box, please let me know.

## Dependencies

Doldrums requires [pyelftools](https://github.com/eliben/pyelftools) to parse the ELF format. You can install it with
```
pip3 install pyelftools
```

## Usage

To use, simply run the following command, substituting `libapp.so` for the appropriate binary, and `output` for the desired output file. Note that the verbose option only works for Dart snapshot v2.12.
```
python3 src/main.py [-v] libapp.so output
```

The expected output is a dump of all classes, in the following format:
```
class MyApp extends StatelessWidget {
    Widget build(DynamicType, DynamicType) {
        Code at absolute offset: 0xec85c
    }

    String myPrint(DynamicType, DynamicType) {
        Code at absolute offset: 0xeca80
    }
}
```

The absolute code offset indicates the offset into the `libapp.so` file where the native function may be found.

## Reading material

For a detailed write-up on the format, please check my [blog post](https://rloura.wordpress.com/2020/12/04/reversing-flutter-for-android-wip/).

## Related works

[darter](https://github.com/mildsunrise/darter) is a fully implemented and fully tested parser for Dart version 2.5 releases.

## Contribute

If you'd like to help the project, consider making a pull request,  or donating to
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***

Logo by [Luis Fonseca](https://www.linkedin.com/in/luis-pedro-h-fonseca-4776a024/).