For this interface, keychain items are found or defined by a CFDictionary of key-value pairs. Each key in the dictionary identifies one attribute of the keychain item, or a search option. For example, you can use the
kSecClass key to specify that the keychain item is an Internet password, that it has a specific creation date, that it is for the HTTPS protocol, and that only the first match found should be returned. The keys that can be used for this purpose and the possible values for each key are listed in the Keychain Services section.
See the discussion section of the
SecItemCopyMatching(_:_:) function for information about how to construct a keychain-item search dictionary.