1. @coinbase
To open an account on Coinbase youβll need pass an identity verification and add a payment method. After completing the steps youβll be able to operate on it.
2. @binance
To open an account on Binance you have to perform similar actions as if setting up Coinbase. These platforms are the 2 biggest cryptocurrency exchanges as of today π¦
Differences between Coinbase and Binance:
3. @Uniswap
Uniswap is different from Coinbase and Binance because it is based on #decentralized network protocol βοΈ. To use Uniswap you will need to connect your wallet π (#MetaMask π¦, for example). It is very simple!
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Day 75 of #100DaysOfDeFI π today 3/4 of the challenge is done! π Also today I finish exploring Solidity vulnerabilities with learning about Denial of service (DoS) attacks π¦ΉπΌββοΈ #womenwhocode#100DaysOfCode
How it works π§΅
1/ There are many ways to attack a smart contract and at some point create a DoSβ‘
2/ Denial of Service attack paralyzes a smart contract and makes it temporarily unusable π
Day 74 of #100DaysOfDeFI π Today I learned about Delegate Call vulnerability in #Solidity π¦ΉπΌββοΈ When using delegatecall opcode one should be careful because wrong usage will lead to unexpected results β οΈ #womenwhocode#100DaysOfCode
How it works π§΅
1/ What delegatecall is? When contract A uses delegatecall to call contract B it means that the contract B code will be executed inside context of the contract A: storage, msg.sender, msg.value, msg.data, etc will be the Aβs context.
2/ Storage layout must be the same for contract A and contract B β it means both contracts should declare the same state variables in the same order πΎ
Day 73 of #100DaysOfDeFI π Learned about Self Destruct vulnerability in #Solidity π¦ΉπΌββοΈ Selfdestruct deletes the contract from the blockchain and and sends all Ether to a designated address πΈ In some scenarios it can lead to unexpected problems β #100DaysOfCode
How it works π§΅
1/ Letβs see how it works with an example of a simple game π² Players send to the contract 1 token πͺ the one who deposits the fifth token wins π
Game code π
1/ An overflow in Solidity occurs when a number is incremented beyond its maximum value. For example, if we have a uint8 with a value of 255 and increment it by 1, it will βresetβ and set a value to 0. Remember, the maximum value for uint8 is 255β
2/ Similar thing happens when we decrease a value beyond its minimal level. Taking the same example, if a uint8 is set to 0 and we decrease it by 1, it will set to 255, since 0 is the minimal value of uint8β
Day 71 of #100DaysOfDeFI π looked at Re-Entrancy vulnerabilityπ¦Ήπ» It is one of the most destructive attacks in the #Solidity smart contracts πΈ The untrusted contract that exploits the vulnerability is able to drain all user's funds π° #100DaysOfCode
How it works π§΅
1/ To make it happen, there should be 2 contracts: a vulnerable contract and an attackerβs contract πΊ
2/ The attacker should deposit some funds into the vulnerable contract π°
1/ The Factory will include:
π· createPair - create a Liquidity Pool;
π· adjustAmount - adjust a number of tokens using a formula;
π· getReserves - a getter function;
π· addLiquidity - add liquidity to the LP;
π· removeLiquidity - withdraw liquidity;
π· trade1for2 - swap tokens.