In fact, knetworkmanager seems to have been designed this way, as shown in the FAQ:
Q: How can I store passphrases associated with encrypted wireless networks? A: Activate KWallet support: * start kwalletmanager * right click wall icon in tray * "Configure Wallet" * Check "Enable the KDE wallet subsystem" on the tab "Wallet Preferences" http://en.opensuse.org/Projects/KNetworkManager -- KnetworkManager doesn't save the WPA Key unless Kwallet is installed and configured https://launchpad.net/bugs/48225 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
