evmole 0.3.1

Extracts function selectors and arguments from EVM bytecode
Documentation

EVMole

npm Crates.io PyPI license

This library extracts function selectors and arguments from Ethereum Virtual Machine (EVM) bytecode, even for unverified contracts.

  • JavaScript, Rust and Python implementations
  • Clean code with zero external dependencies (py & js)
  • Faster and more accurate than other existing tools
  • Tested on Solidity and Vyper compiled contracts

Try it online

Usage

JavaScript

$ npm i evmole

import {functionArguments, functionSelectors} from 'evmole'
// Also supported: const e = require('evmole'); e.functionSelectors();

const code = '0x6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256fea2646970667358221220fbd308f142157eaf0fdc0374a3f95f796b293d35c337d2d9665b76dfc69501ea64736f6c63430008170033'
console.log( functionSelectors(code) )
// Output(list): [ '2125b65b', 'b69ef8a8' ]

console.log( functionArguments(code, '2125b65b') )
// Output(str): 'uint32,address,uint224'

Rust

Documentation available on docs.rs

let code = hex::decode("6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256fea2646970667358221220fbd308f142157eaf0fdc0374a3f95f796b293d35c337d2d9665b76dfc69501ea64736f6c63430008170033").unwrap();

println!("{:x?}", evmole::function_selectors(&code, 0));
// Output(Vec<[u8;4]>): [[21, 25, b6, 5b], [b6, 9e, f8, a8]]

println!("{}", evmole::function_arguments(&code, &[0x21, 0x25, 0xb6, 0x5b], 0));
// Output(String): uint32,address,uint224

Python

$ pip install evmole --upgrade

from evmole import function_arguments, function_selectors

code = '0x6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256fea2646970667358221220fbd308f142157eaf0fdc0374a3f95f796b293d35c337d2d9665b76dfc69501ea64736f6c63430008170033'
print( function_selectors(code) )
# Output(list): ['2125b65b', 'b69ef8a8']

print( function_arguments(code, '2125b65b') )
# Output(str): 'uint32,address,uint224'

See examples for more

Benchmark

function selectors

FP/FN - False Positive/False Negative errors; smaller is better

function arguments

Errors - when at least 1 argument is incorrect: (uint256,string) != (uint256,bytes); smaller is better

See benchmark/README.md for the methodology and commands to reproduce these results

versions: evmole v0.3.0; whatsabi v0.9.1; evm-hound-rs v0.1.4; heimdall-rs v0.7.1

How it works

Short: Executes code with a custom EVM and traces CALLDATA usage.

Long: TODO

License

MIT