ethdasm
ethdasm aims to be a disassembler tool for the EVM. It will feature symbol detection and math simplification. I wrote this for fun and it possibly has some bugs. If you think this is neat, send some ether. If you develop a feature, send a PR. If you find a bug, submit an issue. If you want to talk, my email is my first name, my last name, plus [email protected].
ETH: 0x56489eCd3A53bF6407438c28112Ae6956BB5b1EA
Thank you so much for the donations!
Prerequisites
- Python 3.5 or greater
Usage
usage: ethdasm.py [-h] [--decompile] [--disassemble] [--out OUT] input
positional arguments:
input input hex file to parse
optional arguments:
-h, --help show this help message and exit
--decompile decompiles the contract into a python-like pseudo-code
--disassemble disassembly contract into simplified op-codes
--out OUT outputs to a file; outputs to STDOUT if not specified
Symbol identifier
One thing that makes ethdasm very powerful is it's ability to identify symbols in the code. For example, a smart contract header looks something like this:
; Procedure 0x4
[ 0x4] | MSTORE | ['40', '60']
[ 0x5] | CALLDATASIZE | None
[ 0x6] | ISZERO | None
[ 0x7] | PUSH2 | ['002a']
[ 0xa] | JUMPI | None
[ 0xf] | PUSH29 | ['100000000000000000000000000000000000000000000000000000000']
[ 0x12] | CALLDATALOAD | ['00']
[ 0x13] | DIV | None
[ 0x14] | PUSH4 | ['41c0e1b5']
[ 0x19] | DUP2 | None
[ 0x1a] | EQ | None
[ 0x1b] | PUSH2 | ['0070']
[ 0x1e] | JUMPI | None
[ 0x1f] | DUP1 | None
[ 0x20] | PUSH4 | ['f3fef3a3']
[ 0x25] | EQ | None
[ 0x26] | PUSH2 | ['009f']
[ 0x29] | JUMPI | None
We can also resolve this into a python-like pseudo-code.
def main():
MSTORE(40, 60)
var1 = CALLDATASIZE()
var2 = ISZERO(var1)
if var2: func1()
var3 = CALLDATALOAD(00)
var4 = var3 // 100000000000000000000000000000000000000000000000000000000
var5 = var4 == 41c0e1b5
if var5: func2()
var6 = f3fef3a3 == var4
if var6: func3()There is also a complete contract source, bytecode, disassembled bytecode and decompiled bytecode example in the example directory of the repository.