Ethereum Security: Challenges and Best Practices

We will go over all of the Ethereum smart contract best practices in this post.

What is Ethereum smart contract?

An Ethereum smart contract is a kind of account that runs like a coded program and gathers data. It is located on the Ethereum blockchain at a specific address. Smart contracts may transmit transactions over the network and maintain a balance, much like an Ethereum account. Interestingly, though, they are not user-controlled; rather, they are released to the network. User accounts can communicate with them by submitting transactions in accordance with the functions of the individual smart contracts, and they operate as intended by their programming.

Smart contracts specify rules, just like a standard contract does. But how it’s done makes a difference. Rather than merely specifying guidelines, smart contracts use programming to enforce them. Furthermore, smart contract interactions are non-reversible and cannot be automatically erased. Ethereum and other complex blockchain applications are quite experimental. There are always modifications, and new best practices are added as soon as faults or vulnerabilities are found. As a result, there are constant changes and variations in the security landscape.

Solidity best practices for Ethereum smart contracts:

Smart contracts are written in the object-oriented programming language Solidity. Having a thorough grasp of Solidity is beneficial when writing Ethereum smart contracts.

1. Enforce invariants withassert(): An asset guard is activated whenever an assertation fails. For instance, the ratio of token to ether supply in a token issuance contract may be set. With assert(), you may make sure that this always occurs.
2. Just use modifiers while checking. Since the code enclosed in a modifier is often run before the body of the function, any external calls or state changes may cause it to break the checks-effects-interactions pattern. Additionally, since the modifier code may be located distant from the function declaration, developers may overlook it. Modifiers can therefore be used to replace redundant condition checks in various functions. Within the method, developers may also utilize need() and reverse(). By using this technique, you can make your smart contract code easier to read and audit.
3. Use assert() and need() correctly: These are handy methods that may be used to check for conditions and raise an exception if one is found. The need() method should check return values from calls and guarantee valid conditions, whereas the assert() function is only intended to test for internal faults and verify variations.
4. Recognize that when dividing an integer, rounding matters. Divisions by integers are always rounded down to the closest integer. Therefore, you should keep both the numerator and the denominator or use a multiplier if you want greater precision.
5. Recognize the trade-offs between interfaces and abstract contracts. Interfaces and abstract contracts offer a reusable and adaptable method. Interfaces have constraints with regard to inheritance from other interfaces and storage access, although being helpful for drafting contracts prior to implementation. Additionally, they cannot be used for any purpose, which makes abstract contracts more useful than them. Thus, in order to avoid becoming abstract itself, a contract that inherits from an abstract contract needs to implement all of the functions that aren’t implemented.
6. Verify the data length in backup functions. In addition to being used for simple Ether transfers, fallback functions are also utilized in cases where no other function matches, therefore you should always verify their data length. Therefore, you need to make sure that the data is empty if the fallback function is just meant to be used for logging the received Ether. If not, callers will be able to see that your contract is being used inappropriately.
7. Limit lock pragmas to particular compiler iterations. The compiler version that the original authors intended is indicated by a pragmatic. Ensuring that contracts are deployed with the compiler version and flags that have undergone the most testing is crucial. By locking the pragma, you may make sure that they aren’t unintentionally released with a different compiler that has a larger chance of undiscovered flaws.
8. Don’t use tx.origin. Never use tx.origin for permission since it might be called by another contract using money from your contract in some way. Since your current address is tx.origin, your contract will ultimately authorize the transaction. It restricts interoperability as well. Use msg.sender for authorization instead.