Sometimes you have the need for credentials (username/password) in your ADF, or other Fusion Middleware, application. I've seen numerous solutions with property files, web.xml context parameters, deployment plans, etc. Most of these run into problems with SysOps or anyone else worried with security. You don't want these credentials scattered around in plain text files and you don't want developers to know the passwords for each environment. This is better left to configuration by a sys-admin after deployment.
Not everybody seems to know Oracle Fusion Middleware, more specifically Oracle Platform Security Services (OPSS), provides a great solution with the Credentials Store Framework. This is a set of APIs that applications can use to create, read, update, and manage credentials securely.
A credential store is a repository of security data (credentials) that can hold user name and password combinations, tickets, or public key certificates. A credential store can be file-, LDAP- (Oracle Internet Directory), or DB-(Oracle RDBMS)based. A file-based credential store, also referred to as wallet-based and represented by the file cwallet.sso, is the out-of-the-box credential store.
The Credentials Store Framework also limits which application (or components thereof) are allowed to retrieve or modify credentials. This allows for a very secure setup where only trusted libraries that go through extensive auditing are allowed to retrieve credentials.
This post describes the basic steps to get started with the Credentials Store Framework, but more information can be found in the official documentation (Fusion Middleware Application Security Guide):