Smart contract Auditing is an important step in the development and deployment of projects on the blockchain. The immutability is the key reason for the smart contract to be reviewed before deployment. Once deployed, there is little that one can do if vulnerabilities are found in that deployment.
The types of analysis that a smart contract should go through are
a) Testing for all scenarios. The coverage of testing by the dev team reflects their understanding of security and its significance in Web3. This is an important area that auditors should look at and ask developers to cover all areas, both normal cases and abnormal cases. On top of this, the auditors should draft any further cases as they identify to validate and raise to development to fix it.
b) code analysis
Code analysis software examines the smart contract for vulnerabilities. Static code analysis is a process in which the code is analyzed for known vulnerabilities.Tools in this category can identify syntax errors, check for adherence to coding standards, and look for potential security vulnerabilities.
Slither
Slither is an open-source smart contract analysis tool that statically analyses the code. Slither tool consists of a set of detectors to detect the vulnerabilities in the contract. It also provides detailed visual information about the contract, and also it will provide suggestions to optimize the code.
Mythril
Mythril is a Smart contract analysis tool for solidity developed in Python by ConsenSys. It uses symbolic execution to analyze the source code. Mythril will analyze the code by executing the code and monitoring its behaviour on different inputs
c) Fuzzing
Fuzzing is a process where smart contracts are tested for a wide range of inputs and checked on how it works. This technique is very effective to identify bugs in edge cases of data input. Fuzzing is a technique that includes generating random inputs and makes it easy to automatically generate tests to detect violations in assertions and custom properties.
Echidna
Echidna is designed for fuzzing/property-based testing and developed in Haskell programming language.
hevm
The hevm project is an EVM debugger and symbolic execution engine developed by DappHub. Built specifically for symbolic execution, unit testing, and debugging of smart contracts, the hevm command line program houses the capability to symbolically execute and debug smart contracts interactively while performing unit tests and other vulnerability assessments.
Contract Fuzzer
Contract Fuzzer makes use of this technique to find vulnerabilities in Ethereum smart contracts, based on the ABI specifications of smart contracts. In addition, the tool defines test oracles to detect security vulnerabilities, instruments the EVM to log smart contracts runtime behaviors, and analyzes these logs to report security vulnerabilities.
d) Monitoring tools
Tenderly
Tenderly is an all-in-one Web3 development platform that accelerates smart contract development and provides a fully integrated developer experience. It combines in-depth debugging tools with observability and blockchain infrastructure.
Web3 developers can use the Tenderly platform to build, test, monitor, and operate smart contracts in one place. The platform covers every aspect of smart contract development, from inception and prototyping to production monitoring and on-chain usage.
Tenderly is a very handy tool to debug and check how a smart contract is working and also what is the state of the data in the program flow.
The list of tools is growing by the day. So, as auditors, we should define the process and Audit and choose the tools in the path of the audit. As we explore more in-depth, we all will be choosing more effective tools to suit to our review process.