I'm modifying a firmware file (.jic) JTAG Indirect Configuration File with a small algorithm, but changing data inside the file makes it unusable because there is a checksum somewhere in the file that has to be updated.

I need to find where is a checksum inside .jic file and decipher which algorithm is used (crc32, etc).

The bits on each byte are reversed and I inspected the normal and the reversed bit file with no success. 

Does someone know or is there a way to find out where are is the checksum data inside the .jic file?