Hi Mateusz, I hope you're doing well!
There're some files included in the KE06's SDK package which implement a function to calculate CRC, and can be included from the SDK path. The files in question are called crc.h and software_crc_adapter.c.
These files include the HAL_CrcCompute which will compute and return a CRC value using the CRC hardware in the chip.
They can be found in the following path after extracting:
<…\SDK_2.8.0_FRDM-KE06Z\components\crc>
Please let me know if you need any more information.
Best regards,
Sebastián