Set up mask attack for SHA1

Hi
I'm trying to bruteforce one single SHA1 hash. The hash was calculated of a 64 byte string with some known and some unknown bytes. The string consists of bytes from 0x00 to 0xFF. Is it possible to create a position charset where the possible characters range from 0x00 to 0xFF?
Thanks for your help
I'm trying to bruteforce one single SHA1 hash. The hash was calculated of a 64 byte string with some known and some unknown bytes. The string consists of bytes from 0x00 to 0xFF. Is it possible to create a position charset where the possible characters range from 0x00 to 0xFF?
Thanks for your help