Can a cipher use any type of key?

Question

I was wondering if it is possible to load a symmetric key from a keystore and use it in a cipher.
Do ciphers only accept symmetric keys??
I know that the jks keystore only supports asymmetric keys.
Is there a Bouncy Castle keystore that stores symmetric keys?
If so is there a tool that one can use to generate symmetric keys that can be placed in such a keystore (similar to keytool)?
Any help on this would be greatly appreciated.
Thank you,
Blake

Answer 1

KeyStores can not store symmetric keys otherwise known as Secret Keys. They can only store asymmetric keys. And there are no providers out there that can really change that as the public API for KeyStore provides no means by which to implement one.
As for ciphers. There are two types of ciphers. The first is symmetric such as DES, Blowfish, AES, DESede, etc... These ciphers use the same key to init for both encrypt and decrypt (aka the secret key). But there are also asymmetric ciphers of which RSA is by far the most common. In asymmetric ciphers you init the cipher with the public key for encryption and the private key for decryption.
You will have to have a third party provider to use RSA as a cipher as Sun's JCE does not provide an RSA cipher impl. RSA also supports signatures which sun does support.