cksfv is a tool verifying CRC32 checksums and creating checksum files for verification. Read cksfv.1 man page for instructions. See AUTHORS and COPYING files for copyright information. New versions (mainly bug fixes) of the program can be obtained from:
https://gitlab.com/heikkiorsila/cksfv
Should work on most UNIXes, and possibly POSIX emulation layers on Windows. File an issue if there is an incompatibility.
New releases and Git tags are signed with this key: https://zakalwe.fi/~shd/keys/heikki-orsila-2017.pub