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Process Quality Review (0.8)
SushiSwap
PASS
Security Incidents
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.
Smart Contracts & Team
100%
This section looks at the code deployed on the relevant chain that gets reviewed and its corresponding software repository. The document explaining these questions is here.
1. Are the smart contract addresses easy to find? (%)
2. How active is the primary contract? (%)
Contract MasterChefV2 is fairly active, being used 30+ times per day, as indicated in the Appendix.
3. Does the protocol have a public software repository? (Y/N)
SushiSwap's public software repository can be found on GitHub.
4. Is there a development history visible? (%)
At 606 commits and 14 branches, SushiSwap's development history is robust.
5. Is the team public (not anonymous)?
We were able to identify 2 public names contributing to SushiSwap's Github. More public employees were then confirmed by their LinkedIn. Where we found the team is documented in our team appendix at the end of this report.
Documentation
94%
This section looks at the software documentation. The document explaining these questions is here.
6. Is there a whitepaper? (Y/N)
Location: https://docs.sushi.com
7. Is the protocol's software architecture documented? (Y/N)
SushiSwap's software architecture is documented in full here. Software documentation can be found under the corresponding contract's subsection.
8. Does the software documentation fully cover the deployed contracts' source code? (%)
There is 100% coverage of deployed contracts by software function documentation.
9. Is it possible to trace the documented software to its implementation in the protocol's source code? (%)
There is clear association between code and documents via non-explicit traceability between software documentation and implemented code.
Testing
43%
10. Has the protocol tested their deployed code? (%)
Code examples are in the Appendix at the end of this report.. As per the SLOC, there is ___% 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 reviewer's best judgement is the final deciding factor.
11. How covered is the protocol's code? (%)
Bento Box has a code coverage report of 81% from CoverAlls.
12. Does the protocol provide scripts and instructions to run their tests? (Y/N)
Scripts/Instructions location: https://github.com/sushiswap/bentobox/tree/canary/scripts
13. Is there a detailed report of the protocol's test results?(%)
No test report evident anywhere in the SushiSwap documentation, however GitHub code coverage report is available.
14. Has the protocol undergone Formal Verification? (Y/N)
Formal Verification was done by Certora. Evidence of this can be found on Certora's website however the report is not public.
15. Were the smart contracts deployed to a testnet? (Y/N)
Evidence of SushiSwap's testnet deployments can be found here.
Security
83%
This section looks at the 3rd party software audits done. It is explained in this document.
16. Is the protocol sufficiently audited? (%)
SushiSwap was audited in its early stages by PeckShield and partially by Quantstamp, however the reports weren't very thorough but all minor recommendations were fixed and the reports are public. SushiSwap's team has created an audit checklist to mitigate future changes.
17. Is the bounty value acceptably high (%)
SushiSwap offers an active and fruitful bug bounty of up to $1M.
Admin Controls
63%
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.
18. Is the protocol's admin control information easy to find?
SushiSwap's admin control information is documented at this location. This was quick to find.
19. Are relevant contracts clearly labelled as upgradeable or immutable? (%)
All of Sushi's Miso contracts are identified as upgradeable, as identified here. Details can be found under each contract's subsection.
20. Is the type of smart contract ownership clearly indicated? (%)
21. Are the protocol's smart contract change capabilities described? (%)
Smart contract change capabilities are identified in all Miso contracts Admin Functions Overview section. Capabilities for change are not identified for contracts outside of Miso.
22. Is the protocol's admin control information easy to understand? (%)
This information in the Admin Functions section is largely in software specific language, however brief descriptions are easy to understand. Governance model section relates to investment safety in non-software specific language.
23. Is there sufficient Pause Control documentation? (%)
SushiSwap's pause control is mentioned at this location. There is zero evidence of testing.
24. Is there sufficient Timelock documentation? (%)
SushiSwap's timelock documentation can be found at this location. A brief explanation is provided, however the duration is not specified or justified. The Timelock address can be found here.
25. Is the Timelock of an adequate length? (Y/N)
Timelock duration not specified.
Oracles
38%
This section goes over the documentation that a protocol may or may not supply about their Oracle usage. Oracles are a fundamental part of DeFi as they are responsible for relaying tons of price data information to thousands of protocols using blockchain technology. Not only are they important for price feeds, but they are also an essential component of transaction verification and security. These questions are explained in this document.
26. Is the protocol's Oracle sufficiently documented? (%)
Sushi's oracle source is Chainlink, documented at this location. The contracts dependent are identified and relevant software function documentation is provided.
27. Is front running mitigated by this protocol? (Y/N)
SushiSwap does not document any front running mitigation techniques, however they note that bot front-running can be done using the platform.
28. Can flashloan attacks be applied to the protocol, and if so, are those flashloan attack risks mitigated? (Y/N)
SushiSwap documents that flash loans are a feature of BentoBox, however no flashloan countermeasures have ben identified.
Appendices
1/**
2 *Submitted for verification at Etherscan.io on 2021-05-13
3*/
4
5// SPDX-License-Identifier: MIT
6
7// Special Thanks to @BoringCrypto for his ideas and patience
8
9pragma solidity 0.6.12;
10pragma experimental ABIEncoderV2;
11
12// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/math/SignedSafeMath.sol
13library SignedSafeMath {
14 int256 constant private _INT256_MIN = -2**255;
15
16 /**
17 * @dev Returns the multiplication of two signed integers, reverting on
18 * overflow.
19 *
20 * Counterpart to Solidity's `*` operator.
21 *
22 * Requirements:
23 *
24 * - Multiplication cannot overflow.
25 */
26 function mul(int256 a, int256 b) internal pure returns (int256) {
27 // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
28 // benefit is lost if 'b' is also tested.
29 // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
30 if (a == 0) {
31 return 0;
32 }
33
34 require(!(a == -1 && b == _INT256_MIN), "SignedSafeMath: multiplication overflow");
35
36 int256 c = a * b;
37 require(c / a == b, "SignedSafeMath: multiplication overflow");
38
39 return c;
40 }
41
42 /**
43 * @dev Returns the integer division of two signed integers. Reverts on
44 * division by zero. The result is rounded towards zero.
45 *
46 * Counterpart to Solidity's `/` operator. Note: this function uses a
47 * `revert` opcode (which leaves remaining gas untouched) while Solidity
48 * uses an invalid opcode to revert (consuming all remaining gas).
49 *
50 * Requirements:
51 *
52 * - The divisor cannot be zero.
53 */
54 function div(int256 a, int256 b) internal pure returns (int256) {
55 require(b != 0, "SignedSafeMath: division by zero");
56 require(!(b == -1 && a == _INT256_MIN), "SignedSafeMath: division overflow");
57
58 int256 c = a / b;
59
60 return c;
61 }
62
63 /**
64 * @dev Returns the subtraction of t