EVM Bytecode Decompiler
An Ethereum Virtual Machine (EVM) interpreter and decompiler, along with several other utils for programmatically extracting information from bytecode.
Usage
npm i evm
Features
- Converting bytecode to opcodes
- Reading information like events or functions from either bytecode or tx data
- Extracting the swarm hash (if any) from bytecode
API
Methods
- getBytecode() - Get raw bytecode (not really useful; same as input)
- getOpcodes() - Returns opcodes including pc and pushData (if included)
- getFunctions() - Parse functions from their signatures in bytecode
- getEvents() - Parse events from their signatures in bytecode
- getJumpDestinations() - Get array of program counters from JUMPDEST opcodes
- getSwarmHash() - Get Swarm hash (if any) for contract metadata
- reset() - Reset the EVM state (stack, memory, etc.)
- parse() - Interpret opcodes by looping over them, returns array of interpreted opcodes
- decompile() - Decompile bytecode into readable Solidity-like pseudocode
Examples
Converting bytecode to opcodes
Node.js
const { EVM } = require("evm");
const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.HttpProvider("https://api.mycryptoapi.com/eth"));
web3.eth.getCode("0x06012c8cf97BEaD5deAe237070F9587f8E7A266d").then(code => { /* CryptoKitties contract */
const evm = new EVM(code);
console.log(evm.getOpcodes()); /* Get opcodes */
});Browser
const { EVM } = window.EVM_Utils;
const web3 = new Web3(window.web3.currentProvider);
web3.eth.getCode("0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359", function(err,code) { /* DAI contract */
if(err) throw err;
const evm = new EVM(code);
console.log(evm.getOpcodes()); /* Get opcodes */
});Decompiling a contract
Node.js
const { EVM } = require("evm");
const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.HttpProvider("https://api.mycryptoapi.com/eth"));
web3.eth.getCode("0x06012c8cf97BEaD5deAe237070F9587f8E7A266d").then(code => { /* CryptoKitties contract */
const evm = new EVM(code);
console.log(evm.getFunctions()); /* Get functions */
console.log(evm.getEvents()); /* Get events */
console.log(evm.decompile()); /* Decompile bytecode */
});Browser
const { EVM } = window.EVM;
const web3 = new Web3(window.web3.currentProvider);
web3.eth.getCode("0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359", function(err,code) { /* DAI contract */
if(err) throw err;
const evm = new EVM(code);
console.log(evm.getFunctions()); /* Get functions */
console.log(evm.getEvents()); /* Get events */
console.log(evm.decompile()); /* Decompile bytecode */
});Extracting data from transaction
Node.js
const { Transaction } = require("evm");
const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.HttpProvider("https://api.mycryptoapi.com/eth"));
web3.eth.getTransaction("0xd20a8d888a3f29471ea41ea77cc2d95ccd79ade1eaad059e83524e72b9adf962").then(transactionData => {
const transaction = new Transaction();
transaction.setInput(transactionData.input);
console.log(transaction.getFunction()); /* Get function */
});Browser
const { Transaction } = window.EVM;
const web3 = new Web3(window.web3.currentProvider);
web3.eth.getTransaction("0xd20a8d888a3f29471ea41ea77cc2d95ccd79ade1eaad059e83524e72b9adf962", function(err,transactionData) {
if(err) throw err;
const transaction = new Transaction();
transaction.setInput(transactionData.input);
console.log(transaction.getFunction()); /* Get function */
});