How to do a smart contract audit?

How to do a smart contract audit?

To teach you how to conduct an audit, I will audit a contract that I wrote myself. This way you can see real-world audits that you can do yourself.

Now you may be wondering: what exactly does smart contract audit services mean?

Smart contract auditing is a process of careful study of the code. Here, it refers to discovering bugs, vulnerabilities, and risks before deploying the Solidity contract on the Ethereum mainnet and using it; because once published, the code cannot be modified. This definition is for discussion purposes only.

Please note that the audit is not a legal document that verifies the security of the code. No one can be 100% sure that the code will not cause bugs or vulnerabilities in the future. This is just to ensure that your code has been peer reviewed and is basically safe.

Discuss possible improvements, mainly to discover the risks and vulnerabilities of Ether that can harm users.

Ok, now let’s take a look at the structure of a smart contract audit report:

1. Disclaimer: Here it will say that the audit is not a legally binding document, it does not guarantee anything. This is just a discussion paper.
2. Audit overview and great features: Quickly view smart contracts to be audited and find best practices.
3. Contract Attacks — In this section, you will discuss contract attacks and the consequences. This is just to verify that it is really safe.
4. Serious vulnerabilities found in the contract: key issues that can seriously damage the integrity of the contract. Serious issues that would allow attackers to steal ether.
5. Moderate loopholes found in the contract: those that can damage the contract but have limited damage. For example, a bug that allows people to modify random variables.
6. Low severity vulnerabilities: These issues do not actually harm the contract and may already exist in the deployed version of the contract.
7. Line-by-Line Commentary — In this section, you’ll discuss the most important lines that have potential for improvement.
8. Audit summary: your opinion on the contract and the final conclusion on the audit.

Keep this description of the structure in a safe place. This is all you need to do to securely audit smart contracts. It will really help you find those vulnerabilities that are hard to find.

I suggest that you start at point 7 “line by line comment”, because by analyzing the contracts line by line, you will find the most important problems, you will see what is missing and where it should be modified or improved.

Next, I will show you a disclaimer, which you can use as the first step of the audit. You can watch it from point 1 to the end.

Below I’ll show you the completed audit results using this structure, which I did for a contract I wrote myself. You will also see an introduction to the most important attacks that smart contracts can be exposed to in point 3.

Keep this description of the structure in a safe place. This is all you need to do to securely audit smart contracts. It will really help you find those vulnerabilities that are hard to find.

I suggest that you start at point 7 “line by line comment”, because by analyzing the contracts line by line, you will find the most important problems, you will see what is missing and where it should be modified or improved. Next, I will show you a disclaimer, which you can use as the first step of the audit. You can watch it from point 1 to the end.

Below I’ll show you the completed audit results using this structure, which I did for a contract I wrote myself. You will also see an introduction to the most important attacks that smart contracts can be exposed to in point 3.

Disclaimer

The audit will not make a statement or guarantee about the viability of the code, the security of the code, the applicability of the business model, the regulatory system of the business model, or any other statement about the applicability of the contract and the behavior of the contract in a state free of mistakes. The audit document is for discussion purposes only.

Overview

The project has only one file that contains 142 lines of Solidity code Casino.sol. All function and state variable comments follow the standard description format (i.e., the Ethereum Nature Specification format, abbreviated as natspec, which is described in the official Ethereum community code comment format.

excellent features

This contract provides a nice set of functional codes:

Use Oraclize to generate a secure random number and check it in the callback. The modifier checks the end-of-game condition and blocks key features until the rewards are distributed. Please check further to verify that the use of the gamble feature is appropriate. bsc smart contract audit

The winning number is safely generated only when the number of bets reaches the maximum condition.

3. Attacks on the contract

To verify the security of the contract, we test various attacks to ensure that the contract is secure and that best practices are followed.