Using Cryptographic Assets Stored on a Smart Card
...
Because the items appear to your app as standard keychain items, you use Keychain Servicesto to access them. All the usual rules for building a search query and parsing the search results apply. For an example of storing and retrieving keychain items, see Storing Keys in the Keychain. When you work with tokens, the CryptoTokenKit framework handles the storage. You only have to perform item retrieval.