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mStable

93%

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Process Quality Review (0.8)

mStable

Final score:93%
Date:18 Mar 2022
Audit Process:version 0.8
Author:Nick
PQR Score:93%

PASS

Protocol Website:https://mstable.org/

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
Ethereum
Polygon
#QuestionAnswer
100%
1.100%
2.100%
3.Yes
4.100%
5.100
100%
6.Yes
7.Yes
8.100%
9.100%
88%
10.100%
11.92%
12.Yes
13.100%
14.No
15.Yes
93%
16.100%
17.50%
83%
18.100%
19.100%
20.100%
21.100%
22.30%
23.80%
24.100%
25.100%
100%
26.100%
27.Yes
28.Yes
Total:93%

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 2021. 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? (%)

Answer: 100%

They can be found at https://mstable.gitbook.io/developer-docs/contracts/massets , as indicated in the Appendix.

Percentage Score Guidance:
100%
Clearly labelled and on website, documents or repository, quick to find
70%
Clearly labelled and on website, docs or repo but takes a bit of looking
40%
Addresses in mainnet.json, in discord or sub graph, etc
20%
Address found but labeling not clear or easy to find
0%
Executing addresses could not be found

2. How active is the primary contract? (%)

Answer: 100%

Contract mUSD is used 10+ times a day, as indicated in the Appendix.

Percentage Score Guidance:
100%
More than 10 transactions a day
70%
More than 10 transactions a week
40%
More than 10 transactions a month
10%
Less than 10 transactions a month
0%
No activity

3. Does the protocol have a public software repository? (Y/N)

Answer: Yes

Location: https://github.com/mstable

Score Guidance:
Yes
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.
No
For teams with private repositories.

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

Answer: 100%

At 935 commits at 9 branches, this protocol is clearly as stable as the USD peg it seeks to emulate.

Percentage Score Guidance:
100%
Any one of 100+ commits, 10+branches
70%
Any one of 70+ commits, 7+branches
50%
Any one of 50+ commits, 5+branches
30%
Any one of 30+ commits, 3+branches
0%
Less than 2 branches or less than 30 commits

5. Is the team public (not anonymous)?

Answer: 100

This team is public.

Score Guidance:
100%
At least two names can be easily found in the protocol's website, documentation or medium. These are then confirmed by the personal websites of the individuals / their linkedin / twitter.
50%
At least one public name can be found to be working on the protocol.
0%
No public team members could be found.

Documentation

100%

The difference between this and the old link is solely the link.    This section looks at the software documentation. The document explaining these questions is here.

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

Answer: Yes

Location: https://docs.mstable.org/

7. Is the protocol's software architecture documented? (Y/N)

Answer: Yes

This protocol's software architecture is documented in full.

Score Guidance:
Yes
The documents identify software architecture and contract interaction through any of the following: diagrams, arrows, specific reference to software functions or a written explanation on how smart contracts interact.
No
Protocols receive a "no" if none of these are included.

8. Does the software documentation fully cover the deployed contracts' source code? (%)

Answer: 100%

There is full coverage of deployed contracts by software function documentation.

Percentage Score Guidance:
100%
All contracts and functions documented
80%
Only the major functions documented
79 - 1%
Estimate of the level of software documentation
0%
No software documentation

9. Is it possible to trace the documented software to its implementation in the protocol's source code? (%)

Answer: 100%

There is explicit traceability between software documentation and implemented code.

Percentage Score Guidance:
100%
Clear explicit traceability between code and documentation at a requirement level for all code
60%
Clear association between code and documents via non explicit traceability
40%
Documentation lists all the functions and describes their functions
0%
No connection between documentation and code

Testing

88%

10. Has the protocol tested their deployed code? (%)

Answer: 100%

Code examples are in the Appendix at the end of this report.. As per the SLOC, there is 507% 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.

Percentage Score Guidance:
100%
TtC > 120% Both unit and system test visible
80%
TtC > 80% Both unit and system test visible
40%
TtC < 80% Some tests visible
0%
No tests obvious

11. How covered is the protocol's code? (%)

Answer: 92%

mStable has 92% code coverage.

Percentage Score Guidance:
100%
Documented full coverage
99 - 51%
Value of test coverage from documented results
50%
No indication of code coverage but clearly there is a complete set of tests
30%
Some tests evident but not complete
0%
No test for coverage seen

12. Does the protocol provide scripts and instructions to run their tests? (Y/N)

Answer: Yes

Scripts/Instructions location: https://github.com/mstable/mStable-contracts/blob/master/README.md

Score Guidance:
Yes
Scripts and/or instructions to run tests are available in the testing suite
No
Scripts and/or instructions to run tests are not available in the testing suite

13. Is there a detailed report of the protocol's test results?(%)

Answer: 100%

mStable has reports from their GitHub CI reports as well as from coveralls.

Percentage Score Guidance:
100%
Detailed test report as described below
70%
GitHub code coverage report visible
0%
No test report evident

14. Has the protocol undergone Formal Verification? (Y/N)

Answer: No

This protocol has not undergone formal verification.

Score Guidance:
Yes
Formal Verification was performed and the report is readily available
No
Formal Verification was not performed and/or the report is not readily available.

15. Were the smart contracts deployed to a testnet? (Y/N)

Answer: Yes

This protocol has been deployed to a testnet.

Score Guidance:
Yes
Protocol has proved their tesnet usage by providing the addresses
No
Protocol has not proved their testnet usage by providing the addresses

Security

93%

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

16. Is the protocol sufficiently audited? (%)

Answer: 100%

mStable has had audits from ConsenSys Diligence and Bramah Systems (before deployment), as well as from Certik and PeckShield (after deployment). All audit reports can be found here.. There's even a link to the old version of our process quality review - lucky us!

Percentage Score Guidance:
100%
Multiple Audits performed before deployment and the audit findings are public and implemented or not required
90%
Single audit performed before deployment and audit findings are public and implemented or not required
70%
Audit(s) performed after deployment and no changes required. The Audit report is public.
65%
Code is forked from an already audited protocol and a changelog is provided explaining why forked code was used and what changes were made. This changelog must justify why the changes made do not affect the audit.
50%
Audit(s) performed after deployment and changes are needed but not implemented.
30%
Audit(s) performed are low-quality and do not indicate proper due diligence.
20%
No audit performed
0%
Audit Performed after deployment, existence is public, report is not public OR smart contract address' not found.
Deduct 25% if the audited code is not available for comparison.

17. Is the bounty value acceptably high (%)

Answer: 50%

This protocol offers an active bug bounty of $50K

Percentage Score Guidance:
100%
Bounty is 10% TVL or at least $1M AND active program (see below)
90%
Bounty is 5% TVL or at least 500k AND active program
80%
Bounty is 5% TVL or at least 500k
70%
Bounty is 100k or over AND active program
60%
Bounty is 100k or over
50%
Bounty is 50k or over AND active program
40%
Bounty is 50k or over
20%
Bug bounty program bounty is less than 50k
0%
No bug bounty program offered / the bug bounty program is dead
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.

Admin Controls

83%

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?

Answer: 100%

Admin control information is very easy to find.

Percentage Score Guidance:
100%
Admin Controls are clearly labelled and on website, docs or repo, quick to find
70%
Admin Controls are clearly labelled and on website, docs or repo but takes a bit of looking
40%
Admin Control docs are in multiple places and not well labelled
20%
Admin Control docs are in multiple places and not labelled
0%
Admin Control information could not be found

19. Are relevant contracts clearly labelled as upgradeable or immutable? (%)

Answer: 100%

All relevant contracts are clearly labelled in their relative state

Percentage Score Guidance:
100%
Both the contract documentation and the smart contract code state that the code is not upgradeable or immutable.
80%
All Contracts are clearly labelled as upgradeable (or not)
50%
Code is immutable but not mentioned anywhere in the documentation
0%
Admin control information could not be found

20. Is the type of smart contract ownership clearly indicated? (%)

Answer: 100%

Ownership is well explained: it's held in multiple Gnosis safe multisigs.

Percentage Score Guidance:
100%
The type of ownership is clearly indicated in their documentation. (OnlyOwner / MultiSig / etc)
50%
The type of ownership is indicated, but only in the code. (OnlyOwner / MultiSig / etc)
0%
Admin Control information could not be found

21. Are the protocol's smart contract change capabilities described? (%)

Answer: 100%

Smart contract change capabilities are clearly identified in relevant contracts.

Percentage Score Guidance:
100%
The documentation covers the capabilities for change for all smart contracts
50%
The documentation covers the capabilities for change in some, but not all contracts
0%
The documentation does not cover the capabilities for change in any contract

22. Is the protocol's admin control information easy to understand? (%)

Answer: 30%

This information is in software specific language. A non-defi native individual would find understanding this information complicated.

Percentage Score Guidance:
100%
All the contracts are immutable
90%
Description relates to investments safety in clear non-software language
30%
Description all in software-specific language
0%
No admin control information could be found

23. Is there sufficient Pause Control documentation? (%)

Answer: 80%

This protocol's pause control is documented, with the contracts dependent identified.

Percentage Score Guidance:
100%
Pause control(s) are clearly documented and there is records of at least one test within 3 months
80%
Pause control(s) explained clearly but no evidence of regular tests
40%
Pause controls mentioned with no detail on capability or tests
0%
Pause control not documented or explained

24. Is there sufficient Timelock documentation? (%)

Answer: 100%

This protocol has good timelock documentation, with all relevant contracts identified.

Percentage Score Guidance:
100%
Documentation identifies and explains why the protocol does not need a Timelock OR Timelock documentation identifies its duration, which contracts it applies to and justifies this time period.
60%
A Timelock is identified and its duration is specified
30%
A Timelock is identified
0%
No Timelock information was documented

25. Is the Timelock of an adequate length? (Y/N)

Answer: 100%

The timelock is specified as 7 days long.

Percentage Score Guidance:
100%
Timelock is between 48 hours to 1 week OR justification as to why no Timelock is needed / is outside this length.
50%
Timelock is less than 48 hours or greater than 1 week.
0%
No Timelock information was documented OR no timelock length was identified.

Oracles

100%

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. This is explained in this document.

26. Is the protocol's Oracle sufficiently documented? (%)

Answer: 100%

mStable doesn't use oracles, and this is identified and justified in their documentation.

Percentage Score Guidance:
100%
If it uses one, the Oracle is specified. The contracts dependent on the oracle are identified. Basic software functions are identified (if the protocol provides its own price feed data). Timeframe of price feeds are identified. OR The reason as to why the protocol does not use an Oracle is identified and explained.
75%
The Oracle documentation identifies both source and timeframe, but does not provide additional context regarding smart contracts.
50%
Only the Oracle source is identified.
0%
No oracle is named / no oracle information is documented.

27. Is front running mitigated by this protocol? (Y/N)

Answer: Yes

This protocol documents front running mitigation measures in the form of min-price set functions. As an AMM, there is little they can do but this effort earns the points.

Score Guidance:
Yes
The protocol cannot be front run and there is an explanation as to why OR documented front running countermeasures are implemented.
No
The Oracle documentation identifies both source and timeframe, but does not provide additional context regarding smart contracts.

28. Can flashloan attacks be applied to the protocol, and if so, are those flashloan attack risks mitigated? (Y/N)

Answer: Yes

mStable documents flashloan attack countermeasures at this location.

Score Guidance:
Yes
The protocol's documentation includes information on how they mitigate the possibilities and extents of flash loan attacks.
No
The protocol's documentation does not include any information regarding the mitigation of flash loan attacks.

Appendices

1// SPDX-License-Identifier: AGPL-3.0-or-later
2pragma solidity 0.8.6;
3pragma abicoder v2;
4
5// External
6import { IPlatformIntegration } from "../interfaces/IPlatformIntegration.sol";
7import { IInvariantValidator } from "../interfaces/IInvariantValidator.sol";
8import { IBasicToken } from "../shared/IBasicToken.sol";
9
10// Internal
11import "./MassetStructs.sol";
12
13// Libs
14import { SafeCast } from "@openzeppelin/contracts/utils/math/SafeCast.sol";
15import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
16import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
17import { StableMath } from "../shared/StableMath.sol";
18import { MassetHelpers } from "../shared/MassetHelpers.sol";
19
20/**
21 * @title   Manager
22 * @author  mStable
23 * @notice  Simply contains logic to perform Basket Manager duties for an mAsset.
24 *          Allowing logic can be abstracted here to avoid bytecode inflation.
25 * @dev     VERSION: 1.0
26 *          DATE:    2021-01-22
27 */
28library MassetManager {
29    using SafeERC20 for IERC20;
30    using StableMath for uint256;
31
32    event BassetsMigrated(address[] bAssets, address newIntegrator);
33    event TransferFeeEnabled(address indexed bAsset, bool enabled);
34    event BassetAdded(address indexed bAsset, address integrator);
35    event BassetStatusChanged(address indexed bAsset, BassetStatus status);
36    event BasketStatusChanged();
37    event StartRampA(uint256 currentA, uint256 targetA, uint256 startTime, uint256 rampEndTime);
38    event StopRampA(uint256 currentA, uint256 time);
39
40    uint256 private constant MIN_RAMP_TIME = 1 days;
41    uint256 private constant MAX_A = 1e6;
42
43    /**
44     * @notice Adds a bAsset to the given personal, data and mapping, provided it is valid
45     * @param _bAssetPersonal   Basset data storage array
46     * @param _bAssetData       Basset data storage array
47     * @param _bAssetIndexes    Mapping of bAsset address to their index
48     * @param _bAsset           Address of the ERC20 token to add to the Basket
49     * @param _integration      Address of the Platform Integration
50     * @param _mm               Base 1e8 var to determine measurement ratio
51     * @param _hasTxFee         Are transfer fees charged on this bAsset (e.g. USDT)
52     */
53    function addBasset(
54        BassetPersonal[] storage _bAssetPersonal,
55        BassetData[] storage _bAssetData,
56        mapping(address => uint8) storage _bAssetIndexes,
57        address _bAsset,
58        address _integration,
59        uint256 _mm,
60        bool _hasTxFee
61    ) external {
62        require(_bAsset != address(0), "bAsset address must be valid");
63        uint8 bAssetCount = uint8(_bAssetPersonal.length);
64
65        uint8 idx = _bAssetIndexes[_bAsset];
66        require(
67            bAssetCount == 0 || _bAssetPersonal[idx].addr != _bAsset,
68            "bAsset already exists in Basket"
69        );
70
71        // Should fail if bAsset is not added to integration
72        // Programmatic enforcement of bAsset validity should service through decentralised feed
73        if (_integration != address(0)) {
74            IPlatformIntegration(_integration).checkBalance(_bAsset);
75        }
76
77        uint256 bAssetDecimals = IBasicToken(_bAsset).decimals();
78        require(
79            bAssetDecimals >= 4 && bAssetDecimals <= 18,
80            "Token must have sufficient decimal places"
81        );
82
83        uint256 delta = uint256(18) - bAssetDecimals;
84        uint256 ratio = _mm * (10**delta);
85
86        _bAssetIndexes[_bAsset] = bAssetCount;
87
88        _bAssetPersonal.push(
89            BassetPersonal({
90                addr: _bAsset,
91                integrator: _integration,
92                hasTxFee: _hasTxFee,
93                status: BassetStatus.Normal
94            })
95        );
96        _bAssetData.push(BassetData({ ratio: SafeCast.toUint128(ratio), vaultBalance: 0 }));
97
98        emit BassetAdded(_bAsset, _integration);
99    }
100
101    /**
102     * @dev Collects the interest generated from the Basket, minting a relative
103     *      amount of mAsset and sending it over to the SavingsManager.
104     * @param _bAssetPersonal   Basset personal storage array
105     * @param _bAssetData       Basset data storage array
106     * @return indices          Array of bAsset idxs [0,1...]
107     * @return rawGains         Raw increases in vault Balance
108     */
109    function collectPlatformInterest(
110        BassetPersonal[] memory _bAssetPersonal,
111        BassetData[] storage _bAssetData
112    ) external returns (uint8[] memory indices, uint256[] memory rawGains) {
113        // Get basket details
114        BassetData[] memory bAssetData_ = _bAssetData;
115        uint256 count = bAssetData_.length;
116        indices = new uint8[](count);
117        rawGains = new uint256[](count);
118        // 1. Calculate rawGains in each bAsset, in comparison to current vault balance
119        for (uint256 i = 0; i < count; i++) {
120            indices[i] = uint8(i);
121            BassetPersonal memory bPersonal = _bAssetPersonal[i];
122            BassetData memory bData = bAssetData_[i];
123            // If there is no integration, then nothing can have accrued
124            if (bPersonal.integrator == address(0)) continue;
125            uint256 lending = IPlatformIntegration(bPersonal.integrator).checkBalance(
126                bPersonal.addr
127            );
128            uint256 cache = 0;
129            if (!bPersonal.hasTxFee) {
130                cache = IERC20(bPersonal.addr).balanceOf(bPersonal.integrator);
131            }
132            uint256 balance = lending + cache;
133            uint256 oldVaultBalance = bData.vaultBalance;
134            if (balance > oldVaultBalance && bPersonal.status == BassetStatus.Normal) {
135                _bAssetData[i].vaultBalance = SafeCast.toUint128(balance);
136                uint256 interestDelta = balance - oldVaultBalance;
137                rawGains[i] = interestDelta;
138            } else {
139                rawGains[i] = 0;
140            }
141        }
142    }
143
144    /**
145     * @dev Update transfer fee flag for a given bAsset, should it change its fee practice
146     * @param _bAssetPersonal   Basset data storage array
147     * @param _bAssetIndexes    Mapping of bAsset address to their index
148     * @param _bAsset   bAsset address
149     * @param _flag         Charge transfer fee when its set to 'true', otherwise 'false'
150     */
151    function setTransferFeesFlag(
152        BassetPersonal[] storage _bAssetPersonal,
153        mapping(address => uint8) storage _bAssetIndexes,
154        address _bAsset,
155        bool _flag
156    ) external {
157        uint256 index = _getAssetIndex(_bAssetPersonal, _bAssetIndexes, _bAsset);
158        _bAssetPersonal[index].hasTxFee = _flag;
159
160        if (_flag) {
161            // if token has tx fees, it can no longer operate with a cache
162            address integration = _bAssetPersonal[index].integrator;
163            if (integration != address(0)) {
164                uint256 bal = IERC20(_bAsset).balanceOf(integration);
165                if (bal > 0) {
166                    IPlatformIntegration(integration).deposit(_bAsset, bal, true);
167                }
168            }
169        }
170
171        emit TransferFeeEnabled(_bAsset, _flag);
172    }
173
174    /**
175     * @dev Transfers all collateral from one lending market to another - used initially
176     *      to handle the migration between Aave V1 and Aave V2. Note - only supports non
177     *      tx fee enabled assets. Supports going from no integration to integration, but
178     *      not the other way around.
179     * @param _bAssetPersonal   Basset data storage array
180     * @param _bAssetIndexes    Mapping of bAsset address to their index
181     * @param _bAssets          Array of basket assets to migrate
182     * @param _newIntegration   Address of the new platform integration
183     */
184    function migrateBassets(
185        BassetPersonal[] storage _bAssetPersonal,
186        mapping(address => uint8) storage _bAssetIndexes,
187        address[] calldata _bAssets,
188        address _newIntegration
189    ) external {
190        uint256 len = _bAssets.length;
191        require(len > 0, "Must migrate some bAssets");
192
193        for (uint256 i = 0; i < len; i++) {
194            // 1. Check that the bAsset is in the basket
195            address bAsset = _bAssets[i];
196            uint256 index = _getAssetIndex(_bAssetPersonal, _bAssetIndexes, bAsset);
197            require(!_bAssetPersonal[index].hasTxFee, "A bAsset has a transfer fee");
198
199            // 2. Withdraw everything from the old platform integration
200            address oldAddress = _bAssetPersonal[index].integrator;
201            require(oldAddress != _newIntegration, "Must transfer to new integrator");
202            (uint256 cache, uint256 lendingBal) = (0, 0);
203            if (oldAddress == address(0)) {
204                cache = IERC20(bAsset).balanceOf(address(this));
205            } else {
206                IPlatformIntegration oldIntegration = IPlatformIntegration(oldAddress);
207                cache = IERC20(bAsset).balanceOf(address(oldIntegration));
208                // 2.1. Withdraw from the lending market
209                lendingBal = oldIntegration.checkBalance(bAsset);
210                if (lendingBal > 0) {
211                    oldIntegration.withdraw(address(this), bAsset, lendingBal, false);
212                }
213                // 2.2. Withdraw from the cache, if any
214                if (cache > 0) {
215                    oldIntegration.withdrawRaw(address(this), bAsset, cache);
216                }
217            }

JavaScript Tests

Language
Files
Lines
Blanks
Comments
Testing Code
Deployed Code
Complexity
Solidity
32
8254
955
2563
24077
4736
569

Tests to Code: 24077 / 4736 = 508 %