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Process Quality Review (0.7)


Final score:90%
Date:26 Oct 2021
Audit Process:version 0.7
Author:Nic of DeFiSafety
PQR Score:90%


Protocol Website:https://shapeshift.com/

Scoring Appendix

The final review score is indicated as a percentage. The percentage is calculated as Achieved Points due to MAX Possible Points. For each element the answer can be either Yes/No or a percentage. For a detailed breakdown of the individual weights of each question, please consult this document.

The blockchain used by this protocol
BnB Smart Chain

Very simply, the audit looks for the following declarations from the developer's site. With these declarations, it is reasonable to trust the smart contracts.

  • Here is my smart contract on the blockchain
  • You can see it matches a software repository used to develop the code
  • Here is the documentation that explains what my smart contract does
  • Here are the tests I ran to verify my smart contract
  • Here are the audit(s) performed to review my code by third party experts

This report is for informational purposes only and does not constitute investment advice of any kind, nor does it constitute an offer to provide investment advisory or other services. Nothing in this report shall be considered a solicitation or offer to buy or sell any security, token, future, option or other financial instrument or to offer or provide any investment advice or service to any person in any jurisdiction. Nothing contained in this report constitutes investment advice or offers any opinion with respect to the suitability of any security, and the views expressed in this report should not be taken as advice to buy, sell or hold any security. The information in this report should not be relied upon for the purpose of investing. In preparing the information contained in this report, we have not taken into account the investment needs, objectives and financial circumstances of any particular investor. This information has no regard to the specific investment objectives, financial situation and particular needs of any specific recipient of this information and investments discussed may not be suitable for all investors.

Any views expressed in this report by us were prepared based upon the information available to us at the time such views were written. The views expressed within this report are limited to DeFiSafety and the author and do not reflect those of any additional or third party and are strictly based upon DeFiSafety, its authors, interpretations and evaluation of relevant data. Changed or additional information could cause such views to change. All information is subject to possible correction. Information may quickly become unreliable for various reasons, including changes in market conditions or economic circumstances.

This completed report is copyright (c) DeFiSafety 2023. Permission is given to copy in whole, retaining this copyright label.

Code And Team


This section looks at the code deployed on the Mainnet that gets reviewed and its corresponding software repository. The document explaining these questions is here.

1. Are the executing code addresses readily available? (%)

Answer: 100%

All of the executing ShapeShift smart contracts are available in their respective GitHub repositories, as indicated in the Appendix.

Percentage Score Guidance:
Clearly labelled and on website, docs or repo, quick to find
Clearly labelled and on website, docs or repo but takes a bit of looking
Addresses in mainnet.json, in discord or sub graph, etc
Address found but labeling not clear or easy to find
Executing addresses could not be found

2. Is the code actively being used? (%)

Answer: 100%

Activity is 10+ transactions a day on contract FOX Staking Rewards, as indicated in the Appendix.

Percentage Score Guidance:
More than 10 transactions a day
More than 10 transactions a week
More than 10 transactions a month
Less than 10 transactions a month
No activity

3. Is there a public software repository? (Y/N)

Answer: Yes

Is there a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction, it gets a "Yes". For teams with private repositories, this answer is "No"

Score Guidance:
There is a public software repository with the code at a minimum, but also normally test and scripts. Even if the repository was created just to hold the files and has just 1 transaction.
For teams with private repositories.

4. Is there a development history visible? (%)

Answer: 100%

At 2,654 commits and 3 branches, the Fox staking repository is the extensive foxhole network the developer's would like it to be.

This metric checks if the software repository demonstrates a strong steady history. This is normally demonstrated by commits, branches and releases in a software repository. A healthy history demonstrates a history of more than a month (at a minimum).

Percentage Score Guidance:
Any one of 100+ commits, 10+branches
Any one of 70+ commits, 7+branches
Any one of 50+ commits, 5+branches
Any one of 30+ commits, 3+branches
Less than 2 branches or less than 30 commits

5. Is the team public (not anonymous)? (Y/N)

Answer: Yes

For a "Yes" in this question, the real names of some team members must be public on the website or other documentation (LinkedIn, etc). If the team is anonymous, then this question is a "No".



This section looks at the software documentation. The document explaining these questions is here.

6. Is there a whitepaper? (Y/N)

Answer: Yes

7. Are the basic software functions documented? (Y/N)

Answer: Yes

8. Does the software function documentation fully (100%) cover the deployed contracts? (%)

Answer: 100%

All of ShapeShift's main executing contracts and functions are documented at https://raw.githack.com/shapeshift/fox-staking-unified-history/master/docs/index.html#/.

Percentage Score Guidance:
All contracts and functions documented
Only the major functions documented
79 - 1%
Estimate of the level of software documentation
No software documentation

9. Are there sufficiently detailed comments for all functions within the deployed contract code (%)

Answer: 30%

Code examples are in the Appendix. As per the SLOC, there is 30% commenting to code (CtC).

The Comments to Code (CtC) ratio is the primary metric for this score.

Percentage Score Guidance:
CtC > 100 Useful comments consistently on all code
90 - 70%
CtC > 70 Useful comment on most code
60 - 20%
CtC > 20 Some useful commenting
CtC < 20 No useful commenting

10. Is it possible to trace from software documentation to the implementation in code (%)

Answer: 40%

Percentage Score Guidance:
Clear explicit traceability between code and documentation at a requirement level for all code
Clear association between code and documents via non explicit traceability
Documentation lists all the functions and describes their functions
No connection between documentation and code



11. Full test suite (Covers all the deployed code) (%)

Answer: 100%

Code examples are in the Appendix. As per the SLOC, there is 200% testing to code (TtC).

This score is guided by the Test to Code ratio (TtC). Generally a good test to code ratio is over 100%. However the reviewers best judgement is the final deciding factor.

Percentage Score Guidance:
TtC > 120% Both unit and system test visible
TtC > 80% Both unit and system test visible
TtC < 80% Some tests visible
No tests obvious

12. Code coverage (Covers all the deployed lines of code, or explains misses) (%)

Answer: 91%

Percentage Score Guidance:
Documented full coverage
99 - 51%
Value of test coverage from documented results
No indication of code coverage but clearly there is a reasonably complete set of tests
Some tests evident but not complete
No test for coverage seen

13. Scripts and instructions to run the tests? (Y/N)

Answer: Yes

14. Report of the results (%)

Answer: 70%

Percentage Score Guidance:
Detailed test report as described below
GitHub code coverage report visible
No test report evident

15. Formal Verification test done (%)

Answer: 0%

No formal verification was undertaken.

16. Stress Testing environment (%)

Answer: 100%

FOX Staking has been deployed to Rinkeby.



This section looks at the 3rd party software audits done. It is explained in this document.

17. Did 3rd Party audits take place? (%)

Answer: 100%

Multiple audits were performed before the public deployment of multiple of their smart contracts. Notably, the token, and the staker, and airdrop contracts have all been audited pre-launch.

Percentage Score Guidance:
Multiple Audits performed before deployment and results public and implemented or not required
Single audit performed before deployment and results public and implemented or not required
Audit(s) performed after deployment and no changes required. Audit report is public
Audit(s) performed after deployment and changes needed but not implemented
No audit performed
Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address not found, (where question 1 is 0%)
Deduct 25% if code is in a private repo and no note from auditors that audit is applicable to deployed code.

18. Is the bug bounty acceptable high? (%)

Answer: 20%

According to https://shapeshift.com/responsible-disclosure-program, ShapeShift has given approximately 40k in rewards for bug finds.

Percentage Score Guidance:
Bounty is 10% TVL or at least $1M AND active program (see below)
Bounty is 5% TVL or at least 500k AND active program
Bounty is 5% TVL or at least 500k
Bounty is 100k or over AND active program
Bounty is 100k or over
Bounty is 50k or over AND active program
Bounty is 50k or over
Bug bounty program bounty is less than 50k
No bug bounty program offered
An active program means that a third party (such as Immunefi) is actively driving hackers to the site. An inactive program would be static mentions on the docs.

Access Controls


This section covers the documentation of special access controls for a DeFi protocol. The admin access controls are the contracts that allow updating contracts or coefficients in the protocol. Since these contracts can allow the protocol admins to "change the rules", complete disclosure of capabilities is vital for user's transparency. It is explained in this document.

19. Can a user clearly and quickly find the status of the access controls (%)

Answer: 100%

Immutability of contracts and absence of owner privileges are clearly described at https://github.com/shapeshift/fox-staking-unified-history.

Percentage Score Guidance:
Clearly labelled and on website, docs or repo, quick to find
Clearly labelled and on website, docs or repo but takes a bit of looking
Access control docs in multiple places and not well labelled
Access control docs in multiple places and not labelled
Admin Control information could not be found

20. Is the information clear and complete (%)

Answer: 100%

Immutability of contracts and absence of owner privileges are clearly described at https://github.com/shapeshift/fox-staking-unified-history.

Percentage Score Guidance:
All the contracts are immutable -- 100% OR
a) All contracts are clearly labelled as upgradeable (or not) -- 30% AND
b) The type of ownership is clearly indicated (OnlyOwner / MultiSig / Defined Roles) -- 30% AND
c) The capabilities for change in the contracts are described -- 30%

21. Is the information in non-technical terms that pertain to the investments (%)

Answer: 100%

Immutability of contracts and absence of owner privileges are clearly described at https://github.com/shapeshift/fox-staking-unified-history.

Percentage Score Guidance:
All the contracts are immutable
Description relates to investments safety and updates in clear, complete non-software language
Description all in software specific language
No admin control information could be found

22. Is there Pause Control documentation including records of tests (%)

Answer: 100%

Although no pause control function exists in the ShapeShift code, their smart contracts are entirely immutable, and the protocol functionalities that do not make pause control functions a necessity are described at https://github.com/shapeshift/fox-staking-unified-history/blob/master/README.md

Percentage Score Guidance:
All the contracts are immutable or no pause control needed and this is explained OR Pause control(s) are clearly documented and there is records of at least one test within 3 months
Pause control(s) explained clearly but no evidence of regular tests
Pause controls mentioned with no detail on capability or tests
Pause control not documented or explained


 The author of this review is Rex of DeFi Safety.

Email: rex@defisafety.com
Twitter: @defisafety

I started with Ethereum just before the DAO and that was a wonderful education.  It showed the importance of code quality. The second Parity hack also showed the importance of good process.  Here my aviation background offers some value. Aerospace knows how to make reliable code using quality processes.
I was coaxed to go to EthDenver 2018 and there I started SecuEth.org with Bryant and Roman. We created guidelines on good processes for blockchain code development. We got EthFoundation funding to assist in their development Process Quality Reviews are an extension of the SecurEth guidelines that will further increase the quality processes in Solidity and Vyper development. DeFiSafety is my full time gig and we are working on funding vehicles for a permanent staff.

1pragma solidity ^0.7.6;
23import '../openzeppelin-solidity-3.4.0/contracts/token/ERC20/IERC20.sol';
4import '../openzeppelin-solidity-3.4.0/contracts/access/Ownable.sol';
56import './StakingRewards.sol';
78contract StakingRewardsFactory is Ownable {
9    // immutables
10    address public rewardsToken;
11    uint public stakingRewardsGenesis;
1213    // the staking tokens for which the rewards contract has been deployed
14    address[] public stakingTokens;
1516    // info about rewards for a particular staking token
17    struct StakingRewardsInfo {
18        address stakingRewards;
19        uint rewardAmount;
20    }
2122    // rewards info by staking token
23    mapping(address => StakingRewardsInfo) public stakingRewardsInfoByStakingToken;
2425    constructor(
26        address _rewardsToken,
27        uint _stakingRewardsGenesis
28    ) Ownable() {
29        require(_stakingRewardsGenesis >= block.timestamp, 'StakingRewardsFactory::constructor: genesis too soon');
3031        rewardsToken = _rewardsToken;
32        stakingRewardsGenesis = _stakingRewardsGenesis;
33    }
3435    ///// permissioned functions
3637    // deploy a staking reward contract for the staking token, and store the reward amount
38    // the reward will be distributed to the staking reward contract no sooner than the genesis
39    function deploy(address stakingToken, uint rewardAmount) external onlyOwner {
40        StakingRewardsInfo storage info = stakingRewardsInfoByStakingToken[stakingToken];
41        require(info.stakingRewards == address(0), 'StakingRewardsFactory::deploy: already deployed');
4243        info.stakingRewards = address(new StakingRewards(/*_rewardsDistribution=*/ address(this), rewardsToken, stakingToken));
44        info.rewardAmount = rewardAmount;
45        stakingTokens.push(stakingToken);
46    }
4748    ///// permissionless functions
4950    // call notifyRewardAmount for all staking tokens.
51    function notifyRewardAmounts() external {
52        require(stakingTokens.length > 0, 'StakingRewardsFactory::notifyRewardAmounts: called before any deploys');
53        for (uint i = 0; i < stakingTokens.length; i++) {
54            notifyRewardAmount(stakingTokens[i]);
55        }
56    }
5758    // notify reward amount for an individual staking token.
59    // this is a fallback in case the notifyRewardAmounts costs too much gas to call for all contracts
60    function notifyRewardAmount(address stakingToken) public {
61        require(block.timestamp >= stakingRewardsGenesis, 'StakingRewardsFactory::notifyRewardAmount: not ready');
6263        StakingRewardsInfo storage info = stakingRewardsInfoByStakingToken[stakingToken];
64        require(info.stakingRewards != address(0), 'StakingRewardsFactory::notifyRewardAmount: not deployed');
6566        if (info.rewardAmount > 0) {
67            uint rewardAmount = info.rewardAmount;
68            info.rewardAmount = 0;
6970            require(
71                IERC20(rewardsToken).transfer(info.stakingRewards, rewardAmount),
72                'StakingRewardsFactory::notifyRewardAmount: transfer failed'
73            );
74            StakingRewards(info.stakingRewards).notifyRewardAmount(rewardAmount);
75        }
76    }
7879pragma solidity ^0.7.6;
8081import "../openzeppelin-solidity-3.4.0/contracts/math/Math.sol";
82import "../openzeppelin-solidity-3.4.0/contracts/math/SafeMath.sol";
83import "../openzeppelin-solidity-3.4.0/contracts/token/ERC20/SafeERC20.sol";
84import "../openzeppelin-solidity-3.4.0/contracts/utils/ReentrancyGuard.sol";
8586// Inheritance
87import "./interfaces/IStakingRewards.sol";
88import "./RewardsDistributionRecipient.sol";
8990contract StakingRewards is IStakingRewards, RewardsDistributionRecipient, ReentrancyGuard {
91    using SafeMath for uint256;
92    using SafeERC20 for IERC20;
9394    /* ========= STATE VARIABLES ========= */
9596    IERC20 public rewardsToken;
97    IERC20 public stakingToken;
98    uint256 public periodFinish = 0;
99    uint256 public rewardRate = 0;
100    uint256 public rewardsDuration = 135 days;
101    uint256 public lastUpdateTime;
102    uint256 public rewardPerTokenStored;
103104    mapping(address => uint256) public userRewardPerTokenPaid;
105    mapping(address => uint256) public rewards;
106107    uint256 private _totalSupply;
108    mapping(address => uint256) private _balances;
109110    /* ========== CONSTRUCTOR ========== */
111112    constructor(
113        address _rewardsDistribution,
114        address _rewardsToken,
115        address _stakingToken
116    ) {
117        rewardsToken = IERC20(_rewardsToken);
118        stakingToken = IERC20(_stakingToken);
119        rewardsDistribution = _rewardsDistribution;
120    }
121122    /* ========== VIEWS ========== */
123124    function totalSupply() external view override returns (uint256) {
125        return _totalSupply;
126    }
127128    function balanceOf(address account) external view override returns (uint256) {
129        return _balances[account];
130    }
131132    function lastTimeRewardApplicable() public view override returns (uint256) {
133        return Math.min(block.timestamp, periodFinish);
134    }
135136    function rewardPerToken() public view override returns (uint256) {
137        if (_totalSupply == 0) {
138            return rewardPerTokenStored;
139        }
140        return
141            rewardPerTokenStored.add(
142                lastTimeRewardApplicable().sub(lastUpdateTime).mul(rewardRate).mul(1e18).div(_totalSupply)
143            );
144    }
145146    function earned(address account) public view override returns (uint256) {
147        return _balances[account].mul(rewardPerToken().sub(userRewardPerTokenPaid[account])).div(1e18).add(rewards[account]);
148    }
149150    function getRewardForDuration() external view override returns (uint256) {
151        return rewardRate.mul(rewardsDuration);
152    }
153154    /* ========== MUTATIVE FUNCTIONS ========== */
155156    function stakeWithPermit(uint256 amount, uint deadline, uint8 v, bytes32 r, bytes32 s) external nonReentrant updateReward(msg.sender) {
157        require(amount > 0, "Cannot stake 0");
158        _totalSupply = _totalSupply.add(amount);
159        _balances[msg.sender] = _balances[msg.sender].add(amount);
160161        // permit
162        IUniswapV2ERC20(address(stakingToken)).permit(msg.sender, address(this), amount, deadline, v, r, s);
163164        stakingToken.safeTransferFrom(msg.sender, address(this), amount);
165        emit Staked(msg.sender, amount);
166    }
167168    function stake(uint256 amount) external override nonReentrant updateReward(msg.sender) {
169        require(amount > 0, "Cannot stake 0");
170        _totalSupply = _totalSupply.add(amount);
171        _balances[msg.sender] = _balances[msg.sender].add(amount);
172        stakingToken.safeTransferFrom(msg.sender, address(this), amount);
173        emit Staked(msg.sender, amount);
174    }
175176    function withdraw(uint256 amount) public override nonReentrant updateReward(msg.sender) {
177        require(amount > 0, "Cannot withdraw 0");
178        _totalSupply = _totalSupply.sub(amount);
179        _balances[msg.sender] = _balances[msg.sender].sub(amount);
180        stakingToken.safeTransfer(msg.sender, amount);
181        emit Withdrawn(msg.sender, amount);
182    }
183184    function getReward() public override nonReentrant updateReward(msg.sender) {
185        uint256 reward = rewards[msg.sender];
186        if (reward > 0) {
187            rewards[msg.sender] = 0;
188            rewardsToken.safeTransfer(msg.sender, reward);
189            emit RewardPaid(msg.sender, reward);
190        }
191    }
192193    function exit() external override {
194        withdraw(_balances[msg.sender]);
195        getReward();
196    }
197198    /* ========== RESTRICTED FUNCTIONS ========== */
199200    function notifyRewardAmount(uint256 reward) external override onlyRewardsDistribution updateReward(address(0)) {
201        if (block.timestamp >= periodFinish) {
202            rewardRate = reward.div(rewardsDuration);
203        } else {
204            uint256 remaining = periodFinish.sub(block.timestamp);
205            uint256 leftover = remaining.mul(rewardRate);
206            rewardRate = reward.add(leftover).div(rewardsDuration);
207        }
208209        // Ensure the provided reward amount is not more than the balance in the contract.
210        // This keeps the reward rate in the right range, preventing overflows due to
211        // very high values of rewardRate in the earned and rewardsPerToken functions;
212        // Reward + leftover must be less than 2^256 / 10^18 to avoid overflow.
213        uint balance = rewardsToken.balanceOf(address(this));
214        require(rewardRate <= balance.div(rewardsDuration), "Provided reward too high");
215216        lastUpdateTime = block.timestamp;
217        periodFinish = block.timestamp.add(rewardsDuration);
218        emit RewardAdded(reward);
219    }
220221    /* ========== MODIFIERS ========== */
222223    modifier updateReward(address account) {
224        rewardPerTokenStored = rewardPerToken();
225        lastUpdateTime = lastTimeRewardApplicable();
226        if (account != address(0)) {
227            rewards[account] = earned(account);
228            userRewardPerTokenPaid[account] = rewardPerTokenStored;
229        }
230        _;
231    }
232233    /* ========== EVENTS ========== */
234235    event RewardAdded(uint256 reward);
236    event Staked(address indexed user, uint256 amount);
237    event Withdrawn(address indexed user, uint256 amount);
238    event RewardPaid(address indexed user, uint256 reward);
240241interface IUniswapV2ERC20 {
242    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;