How can I list all my passwords stored in Keychain Access?
This will dump your login passwords:
sudo security dump-keychain -d login.keychain &gt; keychain.txt

And this is a script that can convert it to a human readable format: https://gist.github.com/rwest/1583781
NB: The Ruby script worked for me only after I removed the line containing .gsub!('htps', 'https');.
And, optionally, here is an applescript which will autoclick for you the OS security confirmation dialog: https://apple.stackexchange.com/a/137336/66812.