TREZOR 1.4.0 fails on Windows

[bgok]

After upgrading to TREZOR firmware 1.4.0, multibit is not able to communicate with the device.

At first, multibit wasn't able to detect the device. It was due to the issue described at: https://www.reddit.com/r/TREZOR/comments/52tcff/mytrezor_not_working_with_new_firmware/d7ncnqs. After applying the fix, the device was detected, but multibit was still unable to talk to the device. The error that is:

Requesting TREZOR Unlock
Failed to communicate with TREZOR device

Firmware version 1.3.6 works as expected on all platforms. Firmware version 1.4.0 works as expected on Mac osx.

Very little troubleshooting has been done so there may be a simple fix. This possibly includes:

• Rebooting the machine
• Looking at the logs for any clues
• Rebuilding with the most recent .proto files.
• Wiping the device and trying again.

We are shipping with this bug in Multibit release 0.4.1 and will get trezor 1.4.0 working in a future release (hopefully within the next 2 weeks).

@jhoenicke Any ideas about other things we should look for?

[jhoenicke]

The main difference of 1.4.0 is a second hid interface for u2f functionality. The first HID interface enumerated should be the usual Trezor link, the second interface is u2f. You have to make sure to send the commands to the first interface.

Preferred way to distinguish these is by the HID usage page: ff00 for Trezor and f1d0 for u2f. This is sometimes given when enumerating the interfaces, or you can query the report descriptor. You can also use the endpoint (1 vs 3), but boot loader uses different endpoint so this is not reliable.

[bgok]

@jhoenicke Thanks for explaining. That information will be very helping in getting 1.4.0 working.

[prusnak]

Windows (and OS X) HID drivers report usage_page, so that should be the preferred method. Only problem is in Linux/libusb where usage_page is empty and one has to use interface_number (which is empty on Windows/OS X).