This is bogus.

If you execute "security dump-keychain -d login.keychain":

1. If the keychain is unlocked (the keychain is unlocked by default after logging in, and you can check that by opening the Keychain Access app) a SecurityAgent window opens, and you must click the Allow button to dump the keychain. That cannot be scripted in an installation of a recent version of OS X which is not misconfigured.

2. If the keychain is locked (for example, by clicking the padlock in the Keychain Access app to lock it), it asks you for your user password, just like the Keychain Access app does.