if your linux distro is using md5 passwords, you can probably put the hash in /etc/shadow. Add a test user, replace the hash in /etc/shadow with yours from GRUB, then try to login as that user.

Generating checksums—cryptographic hashes such as MD5 or SHA-256 functions for files is hardly anything new and one of the most efficient means to ascertain the integrity of a file, or to check if two ...