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
$ npm i evmole
import {functionArguments, functionSelectors} from 'evmole'
// Also supported: const e = require('evmole'); e.functionSelectors();
const code = '0x6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256'
console.log( functionSelectors(code) )
// Output(list): [ '2125b65b', 'b69ef8a8' ]
console.log( functionArguments(code, '2125b65b') )
// Output(str): 'uint32,address,uint224'
Documentation available on docs.rs
let code = hex::decode("6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256").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
$ pip install evmole --upgrade
from evmole import function_arguments, function_selectors
code = '0x6080604052348015600e575f80fd5b50600436106030575f3560e01c80632125b65b146034578063b69ef8a8146044575b5f80fd5b6044603f3660046046565b505050565b005b5f805f606084860312156057575f80fd5b833563ffffffff811681146069575f80fd5b925060208401356001600160a01b03811681146083575f80fd5b915060408401356001600160e01b0381168114609d575f80fd5b80915050925092509256'
print( function_selectors(code) )
# Output(list): ['2125b65b', 'b69ef8a8']
print( function_arguments(code, '2125b65b') )
# Output(str): 'uint32,address,uint224'
Foundy's cast uses the Rust implementation of EVMole
$ cast selectors $(cast code 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2)
0x06fdde03
0x095ea7b3 address,uint256
0x18160ddd
0x23b872dd address,address,uint256
...
$ cast selectors --resolve $(cast code 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2)
0x06fdde03 name()
0x095ea7b3 address,uint256 approve(address,uint256)
0x18160ddd totalSupply()
0x23b872dd address,address,uint256 transferFrom(address,address,uint256)
...
See examples for more
FP/FN - False Positive/False Negative errors; smaller is better
Dataset | evmole rs Β· js Β· py | whatsabi | sevm | evmhound | heimdall | smpl | |
largest1k 1000 contracts 24427 functions |
FP contracts | 1 π₯ | 0 π₯ | 0 π₯ | 75 | 68 | 95 |
FN contracts | 0 π₯ | 0 π₯ | 0 π₯ | 40 | 103 | 9 | |
FP functions | 192 π₯ | 0 π₯ | 0 π₯ | 720 | 650 | 749 | |
FN functions | 0 π₯ | 0 π₯ | 0 π₯ | 191 | 114 | 12 | |
Time | 0.6s Β· 1.6s Β· 2.1s | 2.9s | 34.8s(*) | 0.7s | 379.5s(*) | 1.7s | |
random50k 50000 contracts 1171102 functions |
FP contracts | 1 π₯ | 43 | 1 | 693 | 519 | 4136 |
FN contracts | 9 π₯ | 11 | 85 | 2903 | 4669 | 77 | |
FP functions | 3 π₯ | 51 | 3 | 10798 | 545 | 14652 | |
FN functions | 10 π₯ | 12 | 1759 | 3538 | 4943 | 96 | |
Time | 9.8s Β· 20.2s Β· 39s | 55.9s | 1343s(*) | 11.5s | 9881.1s(*) | 47.9s | |
vyper 780 contracts 21244 functions |
FP contracts | 0 π₯ | 30 | 0 | 19 | 780 | 185 |
FN contracts | 0 π₯ | 780 | 21 | 300 | 780 | 480 | |
FP functions | 0 π₯ | 30 | 0 | 19 | 780 | 197 | |
FN functions | 0 π₯ | 21244 | 336 | 8273 | 21244 | 12971 | |
Time | 0.4s Β· 0.8s Β· 1.2s | 2.1s | 55.1s(*) | 0.4s | 29.1s(*) | 1.1s |
Errors - when at least 1 argument is incorrect: (uint256,string)
!= (uint256,bytes)
; smaller is better
Dataset | evmole rs Β· js Β· py | heimdall-rs | simple | |
largest1k 1000 contracts 24427 functions |
Errors | 14.0%, 3417 π₯ | 31.1%, 7603 | 58.3%, 14242 |
Time | 1.2s Β· 12.6s Β· 30.1s | 385.6s(*) | 0.6s | |
random50k 50000 contracts 1171102 functions |
Errors | 4.5%, 52777 π₯ | 19.4%, 227078 | 54.9%, 643213 |
Time | 33.7s Β· 337.7s Β· 1002.4s | 9594.6s(*) | 9.6s | |
vyper 780 contracts 21244 functions |
Errors | 49.6%, 10544 π₯ | 100.0%, 21244 | 56.8%, 12077 |
Time | 0.8s Β· 8.0s Β· 16.9s | 29.6s(*) | 0.5s |
See benchmark/README.md for the methodology and commands to reproduce these results
versions: evmole v0.3.7; whatsabi v0.12.0; sevm v0.6.18; evm-hound-rs v0.1.4; heimdall-rs v0.8.3
(*): sevm and heimdall-rs are full decompilers, not limited to extracting function selectors
Short: Executes code with a custom EVM and traces CALLDATA usage.
Long: TODO
MIT