Signed Message Hash not matching in web3py and solidity

[kuabhish]

• Version: 5.10.0
• Python: 3.7
• OS: Ubuntu-18.04

Let's start with comparing results of solidity, web3py and web3js

Writing a signed message

• in web3py

base_message = Web3.soliditySha3( [ 'address' , 'uint256' ] , 
                   [ Web3.toChecksumAddress("0x516510e3B61F3D425Fe5F52D7492E8950C8647D7") , 500])
message = encode_defunct(text=base_message.hex())
signed_message = w3.eth.account.sign_message(message, private_key=private_key)
base_message , signed_message.messageHash
# (HexBytes('0xbccf9f6664ef1f771e15d448d5cccf44e50b6c71a510dc2cb13935e316685e22'),
# HexBytes('0xbf8efb471491d386f2121dda534d499aa84043532aad52af5ee0deb6e74a7c86'))

• in web3js

var base_message = "0x" + abi.soliditySHA3(
        ["address", "uint256"],
        ["0x516510e3B61F3D425Fe5F52D7492E8950C8647D7", 500]
    ).toString("hex");
var signature = web3.eth.accounts.sign( base_message , privateKey );

base_message , signature.messageHash
# 0xbccf9f6664ef1f771e15d448d5cccf44e50b6c71a510dc2cb13935e316685e22,
# 0x38f9b8b605686af16619c42841e230228373d357f7633f2c91bc9e99329f279a

• in solidity

    bytes32 base_message = keccak256(abi.encodePacked(recipient , amount));
    function prefixed(bytes32 hash) public  returns (bytes32) {
        return keccak256(abi.encodePacked( "\x19Ethereum Signed Message:\n32" , hash ));
    }
base_message , message_hash
# 0xbccf9f6664ef1f771e15d448d5cccf44e50b6c71a510dc2cb13935e316685e22
# 0x38f9b8b605686af16619c42841e230228373d357f7633f2c91bc9e99329f279a

For python(web3py) I also tried using encode_intended_validator but that also didn't help me at the end. Problem was the same: message Hash was not matching.

Results

We can see here that the hashes of the web3py and solidity matches. Which I was trying, following what @carver suggested, because I want to recover the signer at the end. So, if the messagehash will match the correct signer we will get.

[carver]

message = encode_defunct(text=base_message.hex())

This is a bug. The code converts the message to a hex-encode string, and then asks encode_defunct() to interpret it as unicode text. Try leaving base_message as pure bytes and simply:

message = encode_defunct(base_message)
Which is equivalent to
message = encode_defunct(primitive=base_message)

See the full method docs at:
https://eth-account.readthedocs.io/en/stable/eth_account.html#eth_account.messages.encode_defunct

Closing issue as not a web3 bug.