bZx V2 PQ Review

Score : 87%

This is a bZx (Version 2) Process Quality Review completed on October 6, 2020. It was performed using the Process Audit process (version 0.5) and is documented here. The review was performed by ShinkaRex of Caliburn Consulting. Check out our Telegram.

This review of V2 bZx was carried after their hack on Sept 13. v1 of bZx was checked on the 21st of July

The final score of the review is 87%, a very solid. The breakdown of the scoring is in Scoring Appendix.

Summary of the Process

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

  1. Here is my smart contract on the blockchain

  2. You can see it matches a software repository used to develop the code

  3. Here is the documentation that explains what my smart contract does

  4. Here are the tests I ran to verify my smart contract

  5. Here are the audit(s) performed to review my code by third party experts

Disclaimer

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, 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. 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.

Executing Code Verification

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

  1. Is the executing code address(s) readily available? (Y/N)

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

  3. Are the Contract(s) Verified/Verifiable? (Y/N)

  4. Does the code match a tagged version in the code hosting platform? (%)

  5. Is the software repository healthy? (%)

Is the executing code address(s) readily available? (Y/N)

Answer: Yes

At the bottom of their long home page, at the footer, simply click "Smart Contracts"

The main contract is available at Address 0xD8Ee69652E4e4838f2531732a46d1f7F584F0b7f as indicated in the Appendix. This review only covers the contract LoanMaintenance.

How to improve this score

Make the ethereum addresses of the smart contract utilized by your application available on either your website or your github (in the README for instance). Ensure the address is up to date. This is a very important question wrt to the final score.

Is the code actively being used? (%)

Answer: 100%

Activity is well in excess of 10 transactions 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

Are the Contract(s) Verified/Verifiable? (Y/N)

Answer: Yes

0xD8Ee69652E4e4838f2531732a46d1f7F584F0b7f is the Etherscan verified contract address.

Does the code match a tagged version on a code hosting platform? (%)

Answer: 60%

All the files matched the development repo. I could not find a properly labelled branch that did not have old files. There are no releases.

Guidance:

100% All code matches and Repository was clearly labelled 60 % All code matches but no labelled repository. Repository was found manually 30% Almost all code does match perfectly and repository was found manually 0% Most matching Code could not be found

GitHub address : https://github.com/bZxNetwork/contractsV2

Deployed contracts in the following file;

Matching Repository: https://github.com/bZxNetwork/contractsV2 (the matching files are in the default "development" branch. They match now, but will a

How to improve this score

Ensure there is a clearly labelled repository holding all the contracts, documentation and tests for the deployed code. Ensure an appropriately labeled tag exists corresponding to deployment dates. Release tags are clearly communicated.

Is development software repository healthy? (%)

Answer: 100%

23 branches and over 200 commits. This is a healthy GitHub.

Documentation

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

Required questions are;

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

  2. Are the basic application requirements documented? (Y/N)

  3. Do the requirements fully (100%) cover the deployed contracts? (%)

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

  5. Is it possible to trace software requirements to the implementation in code (%)

Is there a whitepaper? (Y/N)

Answer: Yes

Location: https://bzx.network/pdfs/bZx_lite_paper.pdf

Are the basic application requirements documented? (Y/N)

Answer: Yes

There is clear documentation that covers the primary functions of the protocol.

Location: https://docs.bzx.network/fulcrum-integration/lending#mintwithether-address

How to improve this score

Write the document based on the deployed code. For guidance, refer to the SecurEth System Description Document.

Do the requirements fully (100%) cover the deployed contracts? (%)

Answer: 80%

Most but not all functions in the documentation; https://docs.bzx.network/fulcrum-integration/trading-borrowing and https://docs.bzx.network/fulcrum-integration/lending.

How to improve this score

This score can improve by adding content to the requirements document such that it comprehensively covers the requirements. For guidance, refer to the SecurEth System Description Document . Using tools that aid traceability detection will help.

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

Answer: 40%

Many functions have no commenting. Some have more but not detailed.

Code examples are in the Appendix. As per the SLOC, there is 8% commenting to code.

How to improve this score

This score can improve by adding comments to the deployed code such that it comprehensively covers the code. For guidance, refer to the SecurEth Software Requirements.

Is it possible to trace requirements to the implementation in code (%)

Answer: 60%

The documentation clearly connects the code and the documentation with snippets.

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

How to improve this score

This score can improve by adding traceability from requirements to code such that it is clear where each requirement is coded. For reference, check the SecurEth guidelines on traceability.

Testing

This section looks at the software testing available. It is explained in this document. This section answers the following questions;

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

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

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

  4. Packaged with the deployed code (Y/N)

  5. Report of the results (%)

  6. Formal Verification test done (%)

  7. Stress Testing environment (%)

Is there a Full test suite? (%)

Answer: 100%

A full test suite in the tests directory is available. Test to code ratio is 25% (which is lower than

How to improve this score

This score can improve by adding tests to fully cover the code. Document what is covered by traceability or test results in the software repository.

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

Answer: 50%

As per 50% guidance below.

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 reasonably complete set of tests 30% - Some tests evident but not complete 0% - No test for coverage seen

How to improve this score

This score can improve by adding tests achieving full code coverage. A clear report and scripts in the software repository will guarantee a high score.

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

Answer: Yes

Instruction for the tests are in the GitHub readme.

Packaged with the deployed code (Y/N)

Answer: Yes

Report of the results (%)

Answer: 0%

No report on coverage or successful test execution is evident.

How to improve this score

Add a report with the results. The test scripts should generate the report or elements of it.

Formal Verification test done (%)

Answer: 100%

A report on Formal Verification is part of the audit reports.

Stress Testing environment (%)

Answer: 100%

The Kovan test network addresses are available and in steady use.

Audits

Answer: 100%

Two audits took place just before deployment. Both audits were finalized at the same time as deployment. Neither audit made comments on _internalTransferFrom where the hack finally happened. It is interesting that one audit had 16 findings ( 2 High and 1 Critical [all fixed]) while the other found just 8 minor issues. This is a Process Quality Review and clearly they followed the process properly at this point so we will award the full score

Guidance:

  1. Multiple Audits performed before deployment and results public and implemented or not required (100%)

  2. Single audit performed before deployment and results public and implemented or not required (90%)

  3. Audit(s) performed after deployment and no changes required. Audit report is public. (70%)

  4. No audit performed (20%)

  5. Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address' not found, question 1 (0%)

Appendices

Author Details

The author of this review is Rex of Caliburn Consulting.

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.

Career wise I am a business development manager for an avionics supplier.

Scoring Appendix

Executing Code Appendix

Code Used Appendix

Example Code Appendix

/**
* Copyright 2017-2020, bZeroX, LLC. All Rights Reserved.
* Licensed under the Apache License, Version 2.0.
*/
pragma solidity 0.5.17;
pragma experimental ABIEncoderV2;
import "./LoanTokenLogicStandard.sol";
contract LoanTokenLogicWeth is LoanTokenLogicStandard {
constructor(
address _newOwner)
public
LoanTokenLogicStandard(_newOwner)
{}
function mintWithEther(
address receiver)
external
payable
nonReentrant
returns (uint256 mintAmount)
{
return _mintToken(
receiver,
msg.value
);
}
function burnToEther(
address receiver,
uint256 burnAmount)
external
nonReentrant
returns (uint256 loanAmountPaid)
{
loanAmountPaid = _burnToken(
burnAmount
);
if (loanAmountPaid != 0) {
IWethERC20(wethToken).withdraw(loanAmountPaid);
Address.sendValue(
receiver,
loanAmountPaid
);
}
}
/* Internal functions */
// sentAddresses[0]: lender
// sentAddresses[1]: borrower
// sentAddresses[2]: receiver
// sentAddresses[3]: manager
// sentAmounts[0]: interestRate
// sentAmounts[1]: newPrincipal
// sentAmounts[2]: interestInitialAmount
// sentAmounts[3]: loanTokenSent
// sentAmounts[4]: collateralTokenSent
function _verifyTransfers(
address collateralTokenAddress,
address[4] memory sentAddresses,
uint256[5] memory sentAmounts,
uint256 withdrawalAmount)
internal
returns (uint256 msgValue)
{
address _wethToken = wethToken;
address _loanTokenAddress = _wethToken;
address receiver = sentAddresses[2];
uint256 newPrincipal = sentAmounts[1];
uint256 loanTokenSent = sentAmounts[3];
uint256 collateralTokenSent = sentAmounts[4];
require(_loanTokenAddress != collateralTokenAddress, "26");
msgValue = msg.value;
if (withdrawalAmount != 0) { // withdrawOnOpen == true
IWethERC20(_wethToken).withdraw(withdrawalAmount);
Address.sendValue(
receiver,
withdrawalAmount
);
if (newPrincipal > withdrawalAmount) {
_safeTransfer(_loanTokenAddress, bZxContract, newPrincipal - withdrawalAmount, "27");
}
} else {
_safeTransfer(_loanTokenAddress, bZxContract, newPrincipal, "27");
}

SLOC Appendix

Solidity Contracts

Language

Files

Lines

Blanks

Comments

Code

Complexity

Solidity

53

9930

1338

637

7955

865

Comments to Code 637 / 7955= 8%

Python Tests

Language

Files

Lines

Blanks

Comments

Code

Complexity

Python

27

2438

289

137

2012

3

Tests to Code 2012/ 7955 = 25%