SignatureCollider

Check signature collision between a proxy and implementation

What is signature collision ?

Every function in ethereum has a unique hash of 4 bytes. This is calculated by the below formula

bytes4(keccak256(bytes("transfer(address,uint256)")))

These 4 bytes are called function selectors. On a low level , this is used to identify which function needs to be called. Therefore, in a given contract , all function signatures must be unique. Or it can create huge problem. The solidity compiler prevents this by throwing an error while compiling.

But , when creating proxy and implementation contract, there is a chance , we miss this as there is no direct link between proxy and implementation contract.

Consider this situation:

Proxy contract has this function

function collate_propagate_storage(bytes16) public {
  ERC20.transfer(to,amount);
}

And the implementation has this function

function burn(uint256 amount) public {
  _burn(owner,amount);
}

When a user calls the proxy to transfer tokens, i.e call collate_propagate_storage, the proxy will instead call the burn function . Thereby burning tokens instead of transferring them.

This application prevents this by checking if the function signature of the proxy and implementation are same i.e collide.

To run

npm run collide <Proxy Contract Name> <Implementation contract Name > 

Add Your Proxy file and implementation file in respective folder

Requirements

Foundry

node