GitLab

fix registration, certificate creation and minor fixes

source searches in $PATH which should not be necessary and might be
problematic.

printf is more portable and never interprets any escape characters.

Found by shellcheck.

Found by shellcheck.

Found by shellcheck.

Found by shellcheck.

Found by shellcheck.

We must strip the trailing newline with `echo -n` before we pass it to
perl to convert the hex to binary, not after.