ERC20.permit() may not work because wrong calculation

[c4-submissions]

Lines of code

https://github.com/code-423n4/2023-09-centrifuge/blob/main/src/token/ERC20.sol#L48

Vulnerability details

Impact

Due to wrong calculation of _DOMAIN_SEPARATOR, ERC20.permit() may not verify signature signed by signer. The design is supposed to support offline token approving but can not work as expected.

Proof of Concept

When calculating _DOMAIN_SEPARATOR during tranche token deployment, the field name is also included, but the value is not set in constructor(). It only has correct value when ERC20.file("name", name) is called.

From the user's perspective, they will create signature following EIP-2612, the name of the tranche token will be used for _DOMAIN_SEPARATOR calculation and the result will be different from the value stored in tranche token smart contract, ERC20.permit() will always be reverted because of this incorrect calculation.

Tools Used

Manual review

Recommended Mitigation Steps

Pass name in ERC20.constructor() other than assigning it's value through ERC20.file("name", name):

constructor(string memory _name, string memory _symbol, uint8 decimals_) {
    name = _name,
    symbol = _symbol,
    decimals = decimals_;
    wards[_msgSender()] = 1;
    emit Rely(_msgSender());

    deploymentChainId = block.chainid;
    _DOMAIN_SEPARATOR = _calculateDomainSeparator(block.chainid);
}

Assessed type

Other

[c4-pre-sort]

raymondfam marked the issue as sufficient quality report

[c4-pre-sort]

raymondfam marked the issue as duplicate of #146

[c4-judge]

gzeon-c4 marked the issue as satisfactory