Why does PyUSB / libusb require root (sudo) permissions on Linux?

Question

I have been toying around with PyUSB lately, and found that it works beautifully on Linux (Ubuntu has libusb 0.1 and 1.0, as well as OpenUSB)... but only if I run the program with root privileges (with sudo, of course).

Can anyone tell me why it requires elevated privileges and, more importantly, if I can change the permissions somehow to make it work for normal user accounts?

Answer 1

libusb allows you to manipulate arbitrary USB devices in arbitrary ways. You could format an external USB harddisk, for example.

In general, all direct hardware access requires root privileges, although I guess that actually full root privileges are not required, you should be fine with just CAP_SYS_RAWIO.