🏦 CryptoBank - Decentralized Ether and Token Bank

A Solidity-based smart contract for securely managing Ether and ERC20 tokens with advanced features such as pausing, role-based access control, and recovery mechanisms. The contract follows best practices like the Checks-Effects-Interactions (CEI) pattern and uses call for Ether transfers to prevent gas limit issues.

📑 Table of Contents

• 🧑‍💻 Features
• 🎨 Technology Stack
• 🗂️ Project Structure
• 📖 How to Use This Repo
• 🔮 Future Improvements
• 📜 License

🧑‍💻 Features

• Ether Deposits and Withdrawals: Users can deposit and withdraw Ether securely, with a configurable maximum balance per user.
• ERC20 Token Support: Users can deposit and withdraw ERC20 tokens.
• Pausing: Admins can pause all operations to mitigate risks during emergencies.
• Role-Based Access Control: Only the admin can perform critical operations like pausing, unpausing, and recovering funds.
• Recovery Mechanisms: Admins can recover accidentally sent Ether or ERC20 tokens.
• CEI Pattern: Implements the Checks-Effects-Interactions pattern to prevent reentrancy attacks.
• Use of call for Ether Transfers: Ensures compatibility with contracts that require more than 2300 gas for receiving Ether.

📜 Available Functions

Function Name	Description	Access Control
depositEther()	Allows users to deposit Ether into the contract.	Public
withdrawEther(uint256)	Allows users to withdraw their Ether balance.	Public
depositToken(address, uint256)	Allows users to deposit ERC20 tokens into the contract.	Public
withdrawToken(address, uint256)	Allows users to withdraw their ERC20 token balance.	Public
setMaxEtherBalance(uint256)	Updates the maximum Ether balance allowed per user.	Admin Only
pauseContract()	Pauses all contract operations.	Admin Only
unpauseContract()	Resumes all contract operations.	Admin Only
recoverEtherInContract()	Recovers all Ether held in the contract.	Admin Only
recoverTokensInContract(address, uint256, address)	Recovers ERC20 tokens held in the contract.	Admin Only
transferOwnership(address)	Transfers admin rights to another address.	Admin Only

🔒 Security Considerations

1. CEI Pattern: All Ether withdrawals follow the Checks-Effects-Interactions pattern to prevent reentrancy attacks.
2. Use of call: Ether transfers use call instead of transfer or send to avoid gas limit issues.
3. Pausing: The contract can be paused during emergencies to prevent unauthorized operations.
4. Role-Based Access Control: Only the admin can perform sensitive operations like pausing, unpausing, and fund recovery.

🎨 Technology Stack

Key Technologies

Technology	Purpose & Advantages
Solidity	A secure and efficient programming language for writing Ethereum-based smart contracts.
CEI Pattern	Prevents reentrancy attacks by following the Checks-Effects-Interactions design pattern.
call	Ensures Ether transfers are compatible with contracts requiring more than 2300 gas.
Remix	A powerful web-based IDE for writing, testing, and deploying smart contracts.

Design Practices

• Use of Audited Libraries: Leverages OpenZeppelin's well-audited libraries to ensure security and reliability.
• Event Logging: Implements detailed event logging for all critical operations to enhance transparency and traceability.
• Security Best Practices: Follows Solidity security guidelines, including the use of call and CEI.

🗂️ Project Structure

The project is organized as follows:

src/
├── CryptoBank.sol  # Main contract implementation

📖 How to Use This Repo

Follow these steps to set up and deploy the contract:

⚙️ Setup

1. Clone the repository:

   git clone https://github.com/your-username/CryptoBank.git
   cd CryptoBank

🚀 Deployment

1. Compile the contract using Remix, Foundry, or your preferred deployment tool.

2. Deploy the contract using Remix, Foundry, or your preferred deployment tool.

🧪 Testing

Test the contract using Remix, Foundry, or your preferred deployment tool.

🔮 Future Improvements

• Multi-Token Support: Add support for additional token standards like ERC721 and ERC1155.
• Dynamic Limits: Allow the admin to set dynamic Ether and token limits for users.
• Governance Integration: Introduce a governance mechanism to decentralize decision-making for critical operations.
• Staking Rewards: Implement a staking mechanism to reward users for holding tokens in the contract.
• Upgradeable Contract: Use a proxy pattern to make the contract upgradeable for future feature additions.
• Multisignature Wallet Support: Integrate multisignature wallets for critical administrative actions to enhance security and decentralization.

📜 License

This project is licensed under the GPL-3.0 License. See the LICENSE file for details.