I was having problems with the special characters as well….
I just did a test image and finally got them accepted.
for the password hash I had to use escape characters – w/o quotes
example:
./shadowhash p\@\$\$w0rd>password_hash
Maybe this can be added to the documentation? I would imagine anybody doing this for a company (or paranoid people) would be using “special” characters. It could save people a TON of time (in my case days).