keychain_query.swift

// Query de búsqueda en Keychain
let query: [String: Any] = [
	kSecClass as String: kSecClassGenericPassword,
	kSecAttrService as String : self.serviceName,
	kSecAttrAccount as String: user.name,
	kSecMatchLimit as String: kSecMatchLimitOne,
	kSecReturnAttributes as String: true,
	kSecReturnData as String: true
]

// Referencia donde recogemos el resultado
var item: CFTypeRef?