This is the only post I've been able to find which explains how to sign screensavers, thanks!
I am having some trouble using the installer certificate in the first step.
"security find-identity -p codesigning" only shows "Apple Development: My Name"
But "security find-identity" also shows my "Developer ID Installer" certificate (listed under X.509 Basic)
Do you know how to add the installer certificate to use it with codesigning? I tried "security add-trusted-cert" but couldn't get it to work. I was able to sign in the first step with the Apple Development certificate, but then the notarization was rejected (maybe because I didn't use the installer certificate).
Also, I am a bit confused by the final step. It seems you notarize a .zip file, but then you make a different .zip file in the final step?