How to implement the CREATE2 in Python

Question

I'd like to know either how to implement the skinny CREATE2 in Python or a package that provides it.

This is the function I'm trying to port from TypeScript to Python. It calls generateAddress2 with that particular salt (size 32):

export function getUserIdentity(walletAddr) {
    const bytecode = getBytecode(walletAddr)
    const addr = getAddress(
        `0x${generateAddress2(ADDR_FACTORY, Buffer.alloc(32), bytecode).toString(
            "hex"
        )}`
    )
    return { bytecode, addr }
}

And this is the ethereumjs generateAddress2 implementation:

/**
 * Generates an address for a contract created using CREATE2.
 * @param from The address which is creating this new address
 * @param salt A salt
 * @param initCode The init code of the contract being created
 */
export const generateAddress2 = function(from: Buffer, salt: Buffer, initCode: Buffer): Buffer {
  assertIsBuffer(from)
  assertIsBuffer(salt)
  assertIsBuffer(initCode)

  assert(from.length === 20)
  assert(salt.length === 32)

  const address = keccak256(
    Buffer.concat([Buffer.from('ff', 'hex'), from, salt, keccak256(initCode)]),
  )

  return address.slice(-20)
}

Many thanks!

Answer 1

Sorted, just in case it helps anyone:

@pytest.mark.parametrize('address, salt, init_code, expected_address', [
    (
        '0x0000000000000000000000000000000000000000',
        '0x0000000000000000000000000000000000000000000000000000000000000000',
        '0x00',
        '0x4D1A2e2bB4F88F0250f26Ffff098B0b30B26BF38',
    ),
    (
        '0xdeadbeef00000000000000000000000000000000',
        '0x0000000000000000000000000000000000000000000000000000000000000000',
        '0x00',
        '0xB928f69Bb1D91Cd65274e3c79d8986362984fDA3',
    ),
    (
        '0xdeadbeef00000000000000000000000000000000',
        '0x000000000000000000000000feed000000000000000000000000000000000000',
        '0x00',
        '0xD04116cDd17beBE565EB2422F2497E06cC1C9833',
    ),
    (
        '0x0000000000000000000000000000000000000000',
        '0x0000000000000000000000000000000000000000000000000000000000000000',
        '0xdeadbeef',
        '0x70f2b2914A2a4b783FaEFb75f459A580616Fcb5e',
    ),
    (
        '0x00000000000000000000000000000000deadbeef',
        '0x00000000000000000000000000000000000000000000000000000000cafebabe',
        '0xdeadbeef',
        '0x60f3f640a8508fC6a86d45DF051962668E1e8AC7',
    ),
    (
        '0x00000000000000000000000000000000deadbeef',
        '0x00000000000000000000000000000000000000000000000000000000cafebabe',
        '0xdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef',
        '0x1d8bfDC5D46DC4f61D6b6115972536eBE6A8854C',
    ),
    (
        '0x0000000000000000000000000000000000000000',
        '0x0000000000000000000000000000000000000000000000000000000000000000',
        '0x',
        '0xE33C0C7F7df4809055C3ebA6c09CFe4BaF1BD9e0',
    ),
])
def test_create2(address, salt, init_code, expected_address):
    """Test the CREATE2 opcode Python implementation.

    EIP-104
    https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1014.md
    """
    from eth_utils import to_checksum_address
    from web3 import Web3

    pre = '0xff'
    b_pre = bytes.fromhex(pre[2:])
    b_address = bytes.fromhex(address[2:])
    b_salt = bytes.fromhex(salt[2:])
    b_init_code = bytes.fromhex(init_code[2:])

    keccak_b_init_code = Web3.keccak(b_init_code)
    b_result = Web3.keccak(b_pre + b_address + b_salt + keccak_b_init_code)
    result_address = to_checksum_address(b_result[12:].hex())

    assert result_address == expected_address