I'm building a web application which configures and interconnects other applications through web services.
In all the data I have to save for each applications, there are some that are quite sensitive : the credentials.
Unfortunately, most of these applications do not provide dedicated API keys or token for this kind of usage, which means I have to store login, passwords of a technical users. And in some cases, client authentication certificates with their passwords.
These data must be accessible to users (as long as they have the permissions) in "clear text" because they can be updated. They also have to be in "clear text" to the server because we can reconfigure every application at any time with the data we want.
What are the options to protect the best we can these data ? Obviously storing them in "clear text" in the database doesn't seem like a secure option despite being convenient.