frida-host

frida-host, a opensource software that allows you to use multiple source files when using frida.

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Purpose

This project is useful when your script is going big. This usually happen during reverse-engineering some C++ project that you may face reading a complex structure (class) in stdlib (like Vec or std::string). Also this project can bring you Typescript support!

But you may ask, what's the difference between this project and frida-compile?

Basically, both can do the same thing, build bundles. The difference is that this project is more easy to use. Check out the following table so you will know!

/	frida-host	frida-compile
Bundle creation	ESBuild	TSC
Performance	ESBuild Level Fast	TSC Level Fast
Attach to Process	✅	❌
Reload-on-Change	✅	❌
Lightweight	✅	✅
Type checking	❌	✅

How to use

A recommend file stucture is given below

- remote/
    - init.js (default entrypoint)
    - other scripts...
- host.config.js (server file)

Install necessary packages

pnpm install frida-host @types/frida-gum frida esbuild

frida package is required because frida node binding is compiled when you install the package, and the same concept applies to esbuild, since it's written in golang.

Typescript package is not required to use typescript in your project, however it is recommended to install. You should always run tsc -noEmit to do type checking becuase ESBuild does not do type checking at all.

# Optional if you'd like to use Typescript
pnpm install typescript -D

Server File

You need to create a config file. Recommended name is 'ff.config.js'. Use the following template to get started quickly.

const { defineConfig, startHost } = require('frida-host')

const conf = defineConfig({
    target: {
        name: "App",
        package: "com.example.app",
        source: "usb"
    },
    attachPreference: "try",
    entryPoint: "./remote/init.js"
})

await startHost(conf)

CLI

You can always use provided CLI to do the exactly same thing as Server File Method does. However, some feature like messageHandler is impossible to implement in CLI tool, so they are not exist in the CLI tool. If you need to use messageHandler, you must use Server File Method

Here is an example on how to spawn and hook 'com.example.app' through usb

$ frida-host ./remote/init.js -u -p com.example.app -t App -s

For more help, please use --help

$ frida-host --help