[CentOS] Passing password to script for rpmsign of list of .rpm files

I am trying to automatize signing of unsigned .rpm files. My repo has at 
least 50 x 3 packages.

But I would have to type numerous passwords for each file. I can not see 
hot to pass pass phrase to script.

rpmsign --resign {--pass=??} <filename from list> ????

Can someone advise me how to do that?

Ljubomir