smom-dbis-138/docs/SMART_CREATE2_DEPLOYMENT.md

Smart CREATE2 Deployment Guide

Overview

Instead of brute-forcing salts, we use Foundry's impersonation features and direct salt calculation to deploy contracts to exact addresses from genesis.json.

Key Insights

1. Foundry Impersonation: Use vm.startBroadcast(address) to impersonate any address (even if we don't have the private key)
2. Salt Calculation: Since addresses are in genesis.json, we can calculate the salt for known deployers
3. No Brute Force Needed: Try common salts first (0, 1, chain ID, contract name, etc.)

Why This Works Better

Old Approach (Brute Force)

• ❌ Tries thousands of salt values
• ❌ Slow and gas-intensive
• ❌ May never find the correct salt

New Approach (Smart Calculation)

• ✅ Tries common salts first (instant)
• ✅ Uses Foundry's impersonation (no private key needed)
• ✅ Leverages the fact that addresses are pre-allocated in genesis.json

Usage

Option 1: Use the Smart Script

# Deploy WETH9
forge script script/DeployWETH9Smart.s.sol:DeployWETH9Smart \
    --rpc-url http://localhost:8545 \
    --broadcast \
    --sender <deployer-address> \
    --legacy

Note: When using --sender, Foundry will impersonate that address using vm.startBroadcast(address).

Option 2: Calculate Parameters First

Run the calculation script to find the salt:

./scripts/deployment/calculate-create2-parameters.sh

This will output the deployer address and salt needed, which you can then use in your deployment script.

How It Works

Step 1: Identify Potential Deployers

Since the addresses are in genesis.json, likely deployers are:

1. Standard CREATE2 deployer (0x4e59b44847b379578588920cA78FbF26c0B4956C)
2. Genesis addresses (those with high balances in genesis.json)
3. CREATE2Factory address (if one exists)

Step 2: Calculate Salt for Each Deployer

For each potential deployer, try common salts:

• 0 (zero)
• 1 (one)
• 138 (chain ID)
• keccak256("WETH9") or keccak256("WETH10")
• keccak256("Wrapped Ether")
• Address-specific values

Step 3: Impersonate and Deploy

Once we find the correct deployer/salt combination:

1. Use vm.startBroadcast(deployerAddress) to impersonate
2. Deploy using CREATE2 with the calculated salt
3. Verify the deployed address matches the target

Example

// Impersonate the CREATE2 deployer (no private key needed!)
vm.startBroadcast(CREATE2_DEPLOYER);

// Deploy with calculated salt
address deployed = deployCreate2(bytecode, calculatedSalt);

// Verify
require(deployed == TARGET_WETH9, "Address mismatch!");

Benefits

1. Faster: Common salts are checked instantly
2. No Private Keys Needed: Uses Foundry's impersonation
3. More Reliable: Leverages genesis.json information
4. Gas Efficient: Only deploys once, doesn't try thousands of salts

Limitations

• If the deployer is unknown or uses an unusual salt, we still need to search
• CREATE2 is a one-way function, so we can't directly reverse it
• Some salts may require sequential search (limited to first 1000)

See Also

• Foundry Impersonation Docs
• CREATE2 EIP-1014
• Deterministic Deployments