Folks Finance - Audit 1

In the contract `f_staking`, the role `admin` has authority over the following functions: - function update_admin() - function add_staking_program() - function add_reward_asset() - function update_end() - function update_reward_rate() - function withdraw_rewards() Any compromise to the admin account may allow a hacker to take advantage of this authority and cause the malfunction of the protocol. In addition, there is no guarantee that there is enough reward balance in the application. The admin can withdraw rewards at any time for any amount by calling function `withdraw_rewards`, and users might not get rewards for the time they already staked.