Verifying installer package signing and notarization using pkgutil

Recently I needed a way to verify whether an installer package was signed and notarized. I’ve been using Apple’s stapler tool as my usual go-to for verifying notarization. However, the stapler tool needs for Xcode to to be installed and I needed a solution that worked regardless of Xcode or the Xcode Command Line Tools being installed on the Mac in question.

After some digging, I found that pkgutil‘s check-signature function on macOS Monterey and later works great for this and doesn’t have any dependencies on Xcode or the Xcode Command Line Tools. The pkgutil tool is installed as part of macOS and the check-signature function displays the following on Monterey and later:

If a package is not signed:

If a package is signed with a certificate:

If a package is signed with a certificate and trusted by Apple’s notarization service:

To use the check-signature function, you should be able to use the command shown below (substituting /path/to/installer.pkg with the actual directory path of the installer package you want to check.):