chriscczhou / erays

Ethereum smart contract reverse engineering

Erays

Erays is an Ethereum smart contract reverse engineering tool. Erays is not a decompiler, but looking at Erays output should be better than staring EVM bytecode.

First you need to remember that I have brain damage. Because brain damage, I use graphviz to generate the output. To install graphviz, run the follwoing:

$ sudo apt install graphviz

To run Erays, use the structurer on a file that contains contract hex string, for example:

$ python structurer.py temp/0x61edcdf5bb737adffe5043706e7c5bb1f1a56eea.hex

Now pdf (yes, brain damage) file for each function in the contract will magically appear in the temp directory. The internal functions are labeled starting from 0x0. The external functions are named after the function signature. A more complex example would be:

$ python structurer.py temp/0x61edcdf5bb737adffe5043706e7c5bb1f1a56eea.hex

Now maybe you will know how they manage the 230 M balance.

The tool should work on the given contracts in the temp directory, which includes a trivial contract, the cryptokitty contract, a high value wallet and an arbitrage.

If you run it on something and it failed, try:

$ python aggregator.py something_that_failed.hex -v

If that failed as well, then maybe it's time to give up.

If the complain was:

GARBAGE bytcode encountered

Then its probably because the bytecode is added after this tool was built (or the contract is nonsense).