Issues with eth_getStorageAt using hardhat

[ehabhussein]

Description:

when using and deploying contracts on hardhat, mythril tries to call eth_getStorageAt it returns an exception as it is calling a storage slot with less than 66 bytes in the rpc call. Example:

mythril.ethereum.interface.rpc.client [DEBUG]: rpc send: {"jsonrpc": "2.0", "method": "eth_getStorageAt", "params": ["0xE7F1725E7734CE288F8367E1BB143E90BB3F0512", **"0x7",** "latest"], "id": 1} urllib3.connectionpool [DEBUG]: http://localhost:8545 "POST / HTTP/1.1" 200 335 mythril.ethereum.interface.rpc.client [DEBUG]: rpc response: {'jsonrpc': '2.0', 'id': 1, 'error': {'code': -32602, 'message': 'Errors encountered in param 1: **Storage slot argument must have a length of 66 ("0x" + 32 bytes), but \'0x7\' has a length of 3', 'data':** {'message': 'Errors encountered in param 1: Storage slot argument must have a length of 66 ("0x" + 32 bytes), but \'0x7\' has a length of 3'}}} mythril.mythril.mythril_analyzer [CRITICAL]: Exception occurred, aborting analysis. Please report this issue to the Mythril GitHub page. Traceback (most recent call last): File "/usr/local/lib/python3.9/dist-packages/mythril/ethereum/interface/rpc/client.py", line 82, in _call return response["result"] KeyError: 'result'

This Exception is raised in File "/usr/local/lib/python3.9/dist-packages/mythril/ethereum/interface/rpc/client.py", line 90

As seen above the data sent was 0x7 but it should 0x000000000000000000000000000000000000000000000000000000007

Testing a solution by modifying the client.py:

 def _call(self, method, params=None, _id=1):
        params = params or []

        print(f"params is: {params}")
        if len(params) > 2 :
            params[1] = "0x"+str(params[1]).replace("0x",'').rjust(67-len(params[1]),"0")
            print(f"params is: {params}")`

How to Reproduce

launch a contract on hardhat and the exception will be raised.

$ myth -v4 analyze --solver-timeout 90000 --rpc localhost:8545 -a 0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512

Expected behavior

$ curl -X POST --data '{"jsonrpc": "2.0", "method": "eth_getStorageAt", "params": ["0xE7F1725E7734CE288F8367E1BB143E90BB3F0512","0x0000000000000000000000000000000000000000000000000000000000000007" ,"0x2"], "id": 1}' http://127.0.0.1:8545

{"jsonrpc":"2.0","id":1,"result":"0x0000000000000000000000000000000000000000000000000000000000000000"}

return a successful response with the value

Environment

└─# pip3 show mythril
Name: mythril
Version: 0.23.9

# uname -a
Linux koli 5.10.0-kali9-amd64 #1 SMP Debian 5.10.46-4kali1 (2021-08-09) x86_64 GNU/Linux

[norhh]

The hardhat version you are using is not compliant with the eth RPC standard (ethers-io/ethers.js#2982).
Since eth_getStorageAt takes its second value as an int.
Try switching to a different hardhat version.