- Option-drag the new openjdk_codesign certificate from the login keychain to the System keychain in the Keychains pane of the main Keychain Access window to make a copy of this certificate in the System keychain. You'll have to authorize a few more times, set it to be "Always trusted" when asked.
- Switch to the System keychain, and drag the copy of openjdk_codesign you just made there onto the desktop.
- Switch to Terminal, and run the following:
sudo security add-trust -d -r trustRoot -p basic -p codeSign -k /Library/Keychains/System.keychain ~/Desktop/openjdk_codesign.cer