Pico FIDO is an open platform, so exercise caution. The flash memory contents can be easily dumped, potentially revealing private/master keys. It is not feasible to encrypt the content, meaning at least one key (the master key) must be stored in clear text.
Note that UF2 files are shipped with a dummy VID/PID to avoid license issues (FEFF:FCFD). If you plan to use it with OpenSC or similar software, you will need to modify the Info.plist of the CCID driver to add these VID/PID values or use the [Pico Patcher tool](https://www.picokeys.com/pico-patcher/).
You can use any VID/PID (e.g., 234b:0000 from FISJ), but remember that you are not authorized to distribute the binary with a VID/PID that you do not own.
After `make` finishes, the binary file `pico_fido.uf2` will be generated. Put your Pico board into loading mode by holding the BOOTSEL button while plugging it in, then copy the UF2 file to the new USB mass storage Pico device. Once copied, the Pico mass storage will disconnect automatically, and the Pico board will reset with the new firmware. A blinking LED will indicate that the device is ready to work.
**Remark:** Pico FIDO uses the HID interface, so VID/PID values are irrelevant in terms of operativity. You can safely use any arbitrary values or the default ones.
Pico FIDO uses the led to indicate the current status. Four states are available:
### Press to confirm
The Led is almost on all the time. It goes off for 100 miliseconds every second.
![Press to confirm](https://user-images.githubusercontent.com/55573252/162008917-6a730eac-396c-44cc-890e-802294be30a3.gif)
### Idle mode
In idle mode, the Pico FIDO goes to sleep. It waits for a command and it is awaken by the driver. The Led is almost off all the time. It goes on for 500 milliseconds every second.
While processing, the Pico FIDO is busy and cannot receive additional commands until the current is processed. In this state, the Led blinks 20 times in a second.
Pico FIDO uses the `HID` driver, which is present in all operating systems. It should be detected by all OS and browser/applications just like normal USB FIDO keys.
Tests can be found in the `tests` folder. They are based on [FIDO2 tests](https://github.com/solokeys/fido2-tests "FIDO2 tests") from Solokeys but adapted to the [python-fido2](https://github.com/Yubico/python-fido2 "python-fido2") v1.0 package, which is a major refactor from the previous 0.8 version and includes the latest improvements from CTAP 2.1.