Apple - How can I retrieve a saved WiFi password from iOS / iPadOS on secure hardware?

One trivial solution is to enable keychain sync for iOS 7 and have the keychain contents sent to iCloud.

Then, on a Mac, enable keychain syncing in the iCloud preference pane in system preferences and use Keychain Utility to inspect the iCloud keychain.

Keychain item contents - showing WiFi password

Once above step is completed. Open Keychains on Mac and look for iCloud on the right panel. You should then see all the SSID you have ever saved on your various devices and computers synced through iCloud.

There is a jailbreak application called WiFi Passwords. It's free by Malcolm Hall in the BigBoss Cydia repository. It allows you to view all of the passwords for the networks that you've joined (including usernames for WPA2 Enterprise networks).