title: Securely store client database details
body: <p>I'm adding functionality for regular exports of data from our databases to a clients database. Clients will supply database details which we need to keep secure. What would the best way of securely storing the connection details, ideally they'd be stored in our main mysql database. I'd definitely want to avoid storing the password's in plaintext.</p>
  
  <p>At the moment my best guess is some form of encryption with a hard coded key in the codebase, but that isn't much better than plaintext.</p>