Skip to content

TESTING.md

Latest commit

 

History

History
106 lines (78 loc) · 3.23 KB

TESTING.md

File metadata and controls

106 lines (78 loc) · 3.23 KB

Testing USB Permissions Fix

Branch: fix/usb-permissions-libusb

Changes Made

1. src/usb/lowlevel/libusb/libusb.go

  • Added Get_Device_List_Filtered() - only opens devices matching specific VID/PID to avoid permission errors
  • Fixed Get_Config_Descriptor() - properly handles gousb's map-based Configs (key=config number, not array index)
  • Fixed endpoint iteration - Endpoints is map[EndpointAddress]EndpointDesc, not a slice

2. src/skywallet/usb/libusb.go

  • Updated Enumerate() to use filtered device enumeration
  • Fixed matchVidPid() - now accepts Skycoin devices (VID 0x313a, PID 0x0001) in all modes
  • Removed SetAutoDetach() call - requires CAP_SYS_ADMIN even with correct udev rules

Testing Instructions

1. Add replace directive to skycoin/go.mod:

replace github.com/skycoin/hardware-wallet-go => ../../skycoin/hardware-wallet-go

2. Build:

cd skycoin
go build -mod=mod -o hw ./cmd/hardware-wallet/skycoin.go

3. Unbind the usbhid kernel driver:

The Skywallet interface (bInterfaceClass=03 HID) gets automatically bound to the usbhid kernel driver. This must be unbound before the application can claim it.

Find the interface path:

# Find your device
lsusb | grep 313a

# If it shows "Bus 001 Device 012", check:
ls -la /sys/bus/usb/devices/*/driver | grep -B2 -A2 313a
# This will show something like "1-1.5:1.0"

Unbind the driver (replace with your interface path):

echo "1-1.5:1.0" | sudo tee /sys/bus/usb/drivers/usbhid/unbind

Verify unbind:

ls -la /sys/bus/usb/devices/1-1.5\:1.0/driver 2>/dev/null || echo "Successfully unbound"

4. Test:

./hw cli features

Permanent Solution via udev

Create /etc/udev/rules.d/51-skywallet.rules:

# Skycoin Hardware Wallet - Unbind HID driver and set permissions
# VID=313a PID=0001

# Unbind HID driver when interface appears
ACTION=="add|bind", SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_interface", \
  ATTRS{idVendor}=="313a", ATTRS{idProduct}=="0001", \
  ATTR{bInterfaceClass}=="03", \
  RUN+="/bin/sh -c 'echo $kernel > /sys/bus/usb/drivers/usbhid/unbind 2>/dev/null || true'"

# Set device permissions  
SUBSYSTEM=="usb", ATTRS{idVendor}=="313a", ATTRS{idProduct}=="0001", MODE="0666", GROUP="plugdev"
KERNEL=="hidraw*", ATTRS{idVendor}=="313a", ATTRS{idProduct}=="0001", MODE="0666", GROUP="plugdev"

Reload udev rules:

sudo udevadm control --reload-rules
sudo udevadm trigger

Then replug the device.

Current Status

✅ Fixed:

  • Config descriptor parsing (gousb map structure)
  • Device enumeration (filtered by VID/PID to avoid permission errors)
  • VID/PID matching for Skycoin hardware wallet (0x313a:0x0001)

✅ Works without sudo (after unbinding usbhid driver)

Technical Notes

Why unbind is needed:

  • Interface class 03 (HID) is auto-claimed by the usbhid kernel driver
  • gousb can't access an interface claimed by another driver
  • Both SetAutoDetach() and manual detachKernelDriver() require CAP_SYS_ADMIN
  • udev rules can unbind automatically on device insertion

Alternative approach (not implemented):

  • Build application with CAP_SYS_ADMIN capability: sudo setcap cap_sys_admin+ep ./hw
  • Security risk - grants broad system privileges