Is the modifications in the .c files and .h files of STL library (en.x-cube-classb-v2-3-0) is allowed?

[Anitha]

Hi,

We integrated en.x-cube-classb-v2-3-0 package in my application. Which is actually failing in runtime CRC test. I reduced the block size, which is actually 64 and I changed to 4  #define STEPS_NUMBER     ((uint32_t)ROM_SIZE/4u) and added some code in the STL_crc32Run(void). Is modification in STL library allowed? As I reduced the block size time taken to complete CRC test is increased? Is there any time constrain to complete CRC test?