Android USB Script

Use at your own risk. For educational purposes only.

An Android app that provides a simple Lua interface for creating and interfacing with arbitrary composite USB devices, allowing your phone to act as a USB device.

Root access is required.

Lua scripts are run as root. Do not run untrusted scripts!

Download debug build artifacts from the latest workflow run.

Demonstration

When interpreted by this app, the following script:

1. Configures your phone to become a USB keyboard
2. Sends a series of key presses to the computer your phone is plugged in to, changing its wallpaper

---
--- Change Windows 10 desktop wallpaper
---

require('common')

kb = luausb.create({ type = "keyboard" })

local file = prompt{
    message="Enter the URL of the wallpaper to download.",
    hint="Image URL",
    default="https://i.imgur.com/46wWHZ3.png"
}

while true do
    print("idle")

    -- wait for USB device to be plugged in
    wait_for_state('configured')
    -- wait for host to detect this USB device
    wait_for_detect(kb)
    print("running")

    kb:chord(MOD_LSUPER, KEY_R)
    wait(2000)
    kb:string("powershell\n")
    wait(2000)
    kb:string("[Net.ServicePointManager]::SecurityProtocol=[Net.SecurityProtocolType]::Tls12;" ..
              "(new-object System.Net.WebClient).DownloadFile('" .. file .. "',\"$Env:Temp\\b.jpg\");\n" ..
              "Add-Type @\"\n" ..
              "using System;using System.Runtime.InteropServices;using Microsoft.Win32;namespa" ..
              "ce W{public class S{ [DllImport(\"user32.dll\")]static extern int SystemParamet" ..
              "ersInfo(int a,int b,string c,int d);public static void SW(string a){SystemParam" ..
              "etersInfo(20,0,a,3);RegistryKey c=Registry.CurrentUser.OpenSubKey(\"Control Pan" ..
              "el\\\\Desktop\",true);c.SetValue(@\"WallpaperStyle\", \"2\");c.SetValue(@\"Tile" ..
              "Wallpaper\", \"0\");c.Close();}}}\n" ..
              "\"@\n" ..
              "[W.S]::SW(\"$Env:Temp\\b.jpg\")\n" ..
              "exit\n")

    print("done")
    -- wait for USB device to be unplugged
    wait_for_state("not attached")
end

The following USB gadgets are currently supported:

• Keyboard (keyboard)
• Mouse (mouse)
• Mass Storage (storage)

Built-in scripts can be run using the "Select Asset" menu item. You can run an external script using the "Load Script" menu item. New demo applications can be added to assets/scripts. The API is pretty much self-documenting, just look at the existing demos to get a feel for how the API works. Several other sample scripts are included in the repository.

Requirements

This app will not work on every Android device. If your Android OS has Linux Kernel version >= 3.18 and is compiled with configfs and f_hid, then the app can try to create usb gadgets.

Troubleshooting

"Device Malfunctioned" on Windows 10

There may be an incompatibility between the supported USB speed between the USB function and USB port. For example, if you try to use the HID function on a port that only supports USB SuperSpeed, you will get this error. This is common when using certain USB 3.0 hubs. If you plugged into a USB hub, try using a port connected to the USB Root Hub. If you plugged into a USB 3.0 port, try using a USB 2.0 port.

"java.io.IOException: Could not write to /dev/hidgX"

Try setting SELinux to permissive mode by running setenforce 0 as root.

Third-party

• libsu
• LuaJ