Canto Identity Subprotocols contest - SaeedAlipoor01988's results

******* Unchecked increment can be used in for-loop *******

Newer versions of the Solidity compiler will check for integer overflows and underflows automatically. This provides safety but increases gas costs. When an unsigned integer is guaranteed to never overflow, the unchecked feature of Solidity can be used to save gas costs. A common case for this is for-loops using a strictly-less-than comparision in their conditional statement, e.g.:

uint256 length = someArray.length; for (uint256 i; i < length; ++i) { }

This example can be replaced with the following construction to reduce gas costs:

for (uint i = 0; i < length) { unchecked { ++i; } }

or

for (uint i = 0; i < length; i = unchecked_inc(i)) { // do something that doesn't change the value of i }

function unchecked_inc(uint i) returns (uint) { unchecked { return i + 1; } }

For more information, consult the following resources:

https://gist.github.com/hrkrshnn/ee8fabd532058307229d65dcd5836ddc#the-increment-in-for-loop-post-condition-can-be-made-unchecked https://docs.soliditylang.org/en/latest/security-considerations.html?highlight=unchecked#two-s-complement-underflows-overflows

The following lines of code are affected:

https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-bio-protocol/src/Bio.sol#L56 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-bio-protocol/src/Bio.sol#L100 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L122 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L127 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L147 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L174 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L129 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L159 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L161 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L109 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L146 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L155 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L164 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L225

******* Use nested if and, avoid multiple check combinations *******

Using nested is cheaper than using && multiple check combinations. There are more advantages, such as easier to read code and better coverage reports.

The following lines of code are affected:

https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L176 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L184 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L240 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L136 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L157 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L186

This example can be replaced with the following construction to reduce gas costs:

•       if (condition == 0) {
  

•           if (condition  == 0) {
  

•               if (condition  == 0) {
  

•                   Error.zeroInput();
  

• }

•           }                                   
  

•       }   
  

******* Use assembly to write address storage values *******

The following lines of code are affected:

https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L80 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L107 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L109

•     revenueAddress = _revenueAddress;
  

•              assembly {                      
  

•                  sstore(revenueAddress .slot, _revenueAddress)
  

•              }  
  

******* Setting the constructor to payable *******

You can cut out 10 opcodes in the creation-time EVM bytecode if you declare a constructor payable. Making the constructor payable eliminates the need for an initial check of msg.value == 0 and saves 13 gas on deployment with no security risks.

The following lines of code are affected:

https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-bio-protocol/src/Bio.sol#L32 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-pfp-protocol/src/ProfilePicture.sol#L57 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L98 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Namespace.sol#L73

Recommendation: Set the constructor to payable

******* Use constants instead of type(uintx).max *******

type(uint120).max or type(uint112).max, etc. it uses more gas in the distribution process and also for each transaction than constant usage.

The following lines of code are affected:

https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L122 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L152 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L184 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L226 https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Tray.sol#L238