SecurityAccessControl – Advanced Solidity Contract (AccessControl + Pausing + Blacklist + Freeze)

This project is an advanced security-focused Solidity smart contract built with Hardhat, Ethers v6, and OpenZeppelin. It expands on the Ownable Tip Jar project by using role-based access control (RBAC) to manage multiple subsystems securely.

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📌 Project Overview

The goal of this contract is to simulate a real Web3 security architecture with:

• Granular multi-role permissions (Admin, Pauser, Blacklister, Freezer, Funder)
• A global emergency pause system
• Blacklist & freeze restrictions
• Reentrancy-safe withdrawals
• Tip storage with event logging
• Full Hardhat + Ethers v6 test suite

All tests pass successfully (41 passing, 0 failing).

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📘 Key Learnings

🔑 1. AccessControl Roles

Unlike Ownable, AccessControl supports flexible permissions. Roles used:

• DEFAULT_ADMIN_ROLE – manages all roles
• PAUSER_ROLE – pause/unpause the contract
• BLACKLISTER_ROLE – restrict malicious accounts
• FREEZER_ROLE – freeze accounts temporarily
• FUNDER_ROLE – withdraws contract balance

⏸ 2. Pausable System

whenNotPaused blocks sensitive functions. Only users with PAUSER_ROLE can trigger pause/unpause.

🚫 3. Blacklist & Freeze Enforcement

Custom modifiers:

• notBlacklisted(account)
• notFrozen(account)

These restrict a user's ability to:

• send tips
• withdraw
• send ETH directly

🔒 4. Safe Withdrawals

Withdrawals use nonReentrant and .call{value: ...}() for safety.

🧪 5. Complete Ethers v6 Test Suite

Tests cover:

• Role assignment
• Unauthorized access reverts
• Pausing behavior
• Blacklist system
• Freeze system
• Tip storage (sendTip/receive/fallback)
• Reentrancy protection
• Withdraw logic

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✨ Contract Features

• Send ETH tips with messages
• Direct ETH support (receive/fallback)
• Retrieve all tips
• Fully permissioned role-based admin system
• Pausable contract state
• Blacklist + freeze functionality
• Secure withdrawals
• ReentrancyGuard protection

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📂 Project Structure

contracts/
  SecurityAccessControl.sol

scripts/
  deploy.js
  interact.js

test/
  AccessControlSecurity.test.js

hardhat.config.js

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▶ How to Run the Project

1. Start a local Hardhat blockchain

npx hardhat node

2. Run tests

npx hardhat test

3. Deploy the contract

npx hardhat run scripts/deploy.js --network localhost

4. Interact with the contract

Examples:

node scripts/interact.js sendTip "Hello world" 0.1
node scripts/interact.js pause
node scripts/interact.js blacklist <address>
node scripts/interact.js balance
node scripts/interact.js withdraw

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🎉 Final Notes

This project represents a major step into enterprise-style Solidity engineering. It demonstrates layered security, permissions architecture, and a full professional workflow from testing → deployment → contract interaction.