How to store multi-tenancy passwords?

Question

How is the proper way to store passwords for each tenancy database?

Tenancy manager:

id | domain      | host      | user | pass  | db
---------------------------------------------------------
1  | website.com | 127.0.0.1 | root | HOW?  | website.com

When a domain connect to application, tenancy manager should get the tenancy information and connect to apropriate database, but, I can't imagine how to store, in a secure way, the password, which I need to decrypt to make each connection.

Maybe a PHP approach is more safe than a database approach? But how?

Answer 1

What about using public/private key encryption mechanism ( http://en.wikipedia.org/wiki/Public-key_cryptography ) . You could persist your passwords in mysql encrypted with a public key. When read the password you could decrypt it with a private key that would be securely stored in your keystore.

you could use http://www.openssl.org/ to create and manage your keystore.