ENS Contest - Aymen0909's results

QA Report

Summary

Findings

1- Immutable state variables lack zero address checks :

Constructors should check the values written in an immutable state variables(address) is not the address(0).

Risk : Low

Proof of Concept

Instances include:

File: DNSRegistrar.sol Line 62-64

previousRegistrar = _previousRegistrar;
resolver = _resolver;
oracle = _dnssec;

File: DNSRegistrar.sol Line 67

ens = _ens;

File: OffchainDNSResolver.sol Line 44-45

ens = _ens;
oracle = _oracle;

Mitigation

Add non-zero address checks in the constructors for the instances aforementioned.

2- Adding a return statement when the function defines a named return variable, is redundant :

Risk : Non critical

Proof of Concept

Instances include:

File: DNSRegistrar.sol Line 204

File: BytesUtils.sol Line 183

File: DNSSECImpl.sol Line 127

File: DNSSECImpl.sol Line 173

Mitigation

Either use the named return variables inplace of the return statement or remove them.

3- Constant redefined elsewhere :

Consider defining in only one contract so that values cannot become out of sync when only one location is updated. A cheap way to store constants in a single location is to create an internal constant in a library. .

Risk : Non critical

Proof of Concept

Instances include:

File: DNSClaimChecker.sol Line 16-17

File: OffchainDNSResolver.sol Line 29-30

uint16 constant CLASS_INET = 1;
uint16 constant TYPE_TXT = 16;

4- Unused imports :

Contracts or libraries that are imported and not used should be removed.

Risk : Non critical

Proof of Concept

Instances include:

File: DNSClaimChecker.sol Line 4

import "../dnssec-oracle/DNSSEC.sol";