If you notice some outdated information please let us know!
Process Quality Review (0.7)
Impermax Finance
PASS
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.
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
90%
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? (%)
Executing code addresses were found at https://docs.impermax.finance/getting-started/deployed-contracts, as seen in the Appendix.
2. Is the code actively being used? (%)
Activity is 63 transactions a day on contract Router.sol, as indicated in the Appendix.
3. Is there a public software repository? (Y/N)
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"
4. Is there a development history visible? (%)
With 17 commits and 1 branch, this is not a healthy repository.
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).
5. Is the team public (not anonymous)? (Y/N)
Full team members information can be found at https://impermax.finance/
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".
Documentation
40%
This section looks at the software documentation. The document explaining these questions is here.
6. Is there a whitepaper? (Y/N)
7. Are the basic software functions documented? (Y/N)
Interest rates' software functions are identified in the Impermax documentation.
8. Does the software function documentation fully (100%) cover the deployed contracts? (%)
Only the software functions of Impermax's interest rates are documented at https://docs.impermax.finance/protocol/interest-rates.
9. Are there sufficiently detailed comments for all functions within the deployed contract code (%)
The Comments to Code (CtC) ratio is the primary metric for this score.
10. Is it possible to trace from software documentation to the implementation in code (%)
There is no explicit traceability between the software documentation and the source code.
Testing
56%
11. Full test suite (Covers all the deployed code) (%)
With a TtC ratio of 265%, this is clearly a well-tested protocol.
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.
12. Code coverage (Covers all the deployed lines of code, or explains misses) (%)
There is evident code coverage available at https://github.com/Impermax-Finance/impermax-x-uniswapv2-core/blob/main/audit/SC_impermax_core.pdf with about a 63% average in coverage between all covered repositories.
13. Scripts and instructions to run the tests? (Y/N)
Instructions available at https://github.com/Impermax-Finance/impermax-x-uniswapv2-core
14. Report of the results (%)
No test report results visible in their documentation.
15. Formal Verification test done (%)
No evidence of a Impermax Finance formal verification on the web or documentation.
16. Stress Testing environment (%)
No testing smart contract addresses found in their documentation.
Security
88%
This section looks at the 3rd party software audits done. It is explained in this document.
17. Did 3rd Party audits take place? (%)
18. Is the bug bounty acceptable high? (%)
There is no evident bug bounty program.
Access Controls
100%
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 (%)
The whitepaper indicates that their smart contracts are immutable.
20. Is the information clear and complete (%)
Their whitepaper indicates that all contracts are immutable.
21. Is the information in non-technical terms that pertain to the investments (%)
Their whitepaper describes that their contracts are immutable.
22. Is there Pause Control documentation including records of tests (%)
Code is indicated as immutable (therefore no pause control).
Appendices
1pragma solidity =0.5.16;
2
3import "./BStorage.sol";
4import "./PoolToken.sol";
5
6contract BInterestRateModel is PoolToken, BStorage {
7
8 / When utilization is 100% borrowRate is kinkBorrowRate * KINK_MULTIPLIER
9 / kinkBorrowRate relative adjustment per second belongs to [1-adjustSpeed, 1+adjustSpeed*(KINK_MULTIPLIER-1)]
10 uint public constant KINK_MULTIPLIER = 5;
11 uint public constant KINK_BORROW_RATE_MAX = 31.7097920e9; //100% per year
12 uint public constant KINK_BORROW_RATE_MIN = 0.31709792e9; //1% per year
13
14 event AccrueInterest(uint interestAccumulated, uint borrowIndex, uint totalBorrows);
15 event CalculateKinkBorrowRate(uint kinkBorrowRate);
16 event CalculateBorrowRate(uint borrowRate);
17
18 function _calculateBorrowRate() internal {
19 uint _kinkUtilizationRate = kinkUtilizationRate;
20 uint _adjustSpeed = adjustSpeed;
21 uint _borrowRate = borrowRate;
22 uint _kinkBorrowRate = kinkBorrowRate;
23 uint32 _rateUpdateTimestamp = rateUpdateTimestamp;
24
25 // update kinkBorrowRate using previous borrowRate
26 uint32 timeElapsed = getBlockTimestamp() - _rateUpdateTimestamp; // underflow is desired
27 if(timeElapsed > 0) {
28 rateUpdateTimestamp = getBlockTimestamp();
29 uint adjustFactor;
30
31 if (_borrowRate < _kinkBorrowRate) {
32 // never overflows, _kinkBorrowRate is never 0
33 uint tmp = (_kinkBorrowRate - _borrowRate) * 1e18 / _kinkBorrowRate * _adjustSpeed * timeElapsed / 1e18;
34 adjustFactor = tmp > 1e18 ? 0 : 1e18 - tmp;
35 } else {
36 // never overflows, _kinkBorrowRate is never 0
37 uint tmp = (_borrowRate - _kinkBorrowRate) * 1e18 / _kinkBorrowRate * _adjustSpeed * timeElapsed / 1e18;
38 adjustFactor = tmp + 1e18;
39 }
40
41 // never overflows
42 _kinkBorrowRate = _kinkBorrowRate * adjustFactor / 1e18;
43 if(_kinkBorrowRate > KINK_BORROW_RATE_MAX) _kinkBorrowRate = KINK_BORROW_RATE_MAX;
44 if(_kinkBorrowRate < KINK_BORROW_RATE_MIN) _kinkBorrowRate = KINK_BORROW_RATE_MIN;
45
46 kinkBorrowRate = uint48(_kinkBorrowRate);
47 emit CalculateKinkBorrowRate(_kinkBorrowRate);
48 }
49
50 uint _utilizationRate;
Solidity Contracts
Comments to Code: 194 / 1147 = 17 %
JavaScript Tests
Tests to Code: 3040 / 1147 = 265 %