Keccak256 Hash creation - Algorand

Keccak256 Hash creation

post by salman.haider on Jun 30, 2022

I want to create a keccak256 for on 4 different arguments that my function will receive:

myFunction((token: TealType.uint64, amount: TealType.uint64, payee: TealType.bytes, salt: TealType.bytes)

- First I want to generate a hash based on this messageKECCAK256(BYTES("WithdrawSigned(token,payee,amount,salt)")),

PYTEAL CODE:


withdrawSignedMethod.store(Bytes("WithdrawSigned(token,payee,amount,salt)")),
            withdraw_signed_method.store(Keccak256(withdrawSignedMethod.load())),

withdraw_signed_method.load() is a hash generated from`Bytes("WithdrawSigned(token,payee,amount,salt)")

NOW, I want to create hash from the withdraw_signed_method hash and all other function parameters

PYTEAL CODE:

            initialS.store(withdraw_signed_method.load(), token, payee, amount, salt),
            signedMessage.store(Keccak256(initialS.load())),

But it doesn’t work and gives this error message:

  File "full-bridge.py", line 100, in withdraw_token
    initialS.store(withdraw_signed_method.load(), token, payee, amount, salt),
TypeError: store() takes 2 positional arguments but 6 were given

Could you please suggest a way using which I would be able to generate hash for all of my input parameters, I’m stuck on this problem for past 1 week?

post by Ben on Jun 30, 2022

Hi salman,

The store method takes a single argument, the value you wish to store in scratch space. Are you trying to hash the concatenated values of all the arguments? If so you can convert the arguments you passed there (if relevant) to bytes with Concat then hash the resulting bytes with Keccack256.

post by salman.haider on Jun 30, 2022

Can you share a possible syntax for that solution you are suggesting?

I tried the below mentioned solution but I feel it would concat the keys but I want to concat the values of the particular parameters.

            initialS.store(Concat(withdraw_signed_method.load(), Itob(token), payee, Itob(amount), salt)),
            signedMessage.store(Keccak256(initialS.load())),

Such as the input parameters:


token = 183838
payee = "X9JDHAS03...."
amount = 100
salt = "SOME-HASH"

Now how can I concat the values of these input parameters and then pass it to Keccak256?

post by Ben on Jul 1, 2022

That looks approximately correct based on the description of what you want to do.

You can try logging the value with the Log method and inspect the result or call dryrun or use tealdbg to get a better sense of the output

post by salman.haider on Jul 1, 2022

Also how can I apply EcdsaRecover(App.globalGet(WithdrawSigned), signature),

EcdsaRecover(r, s) isn’t working with pyteal?

post by fabric on Jul 1, 2022

You need to give four arguments to EcdsaRecover.

EcdsaRecover(EcdsaCurve.Secp256k1, d, id, r, s) matches Solidity ecdsa_recover(hash=d, v=id, r, s) in Units and Globally Available Variables — Solidity 0.8.15 documentation

Note also that you need Python3 3.10 and an up to date version of Pyteal to use EcdsaRecover.

post by salman.haider on Jul 5, 2022

Can you please provide me the following that would work with algorand:

Test message m
Signature of that message
Signer ethereum

The one provided in demo.py doesn’t work, I was able to run the example however, the signer is not recovered using the m, signature provided in demo.py file (b"openzeppeline", signature)

post by salman.haider on Jul 6, 2022

The code that you have written (demo.py) is in python, however, I’m using the Javascript sdk for interacting with the ECDSA contract. Here is how I’m interacting with the contract for signing the signature. Moreover, once the message is received in the contract, we apply keccak256 on the message to convert it to hash.


let index = 98492040;
let token_address = 81317600;
account = [];
foreignApp = [];
foreignAssets = [];
foreignAssets.push(token_address);

// withdraw_token(_token,_amount, _receiver, salt, signature),
let action = "withdraw";
let amount = 100;
let message = "OpenZeppelin";
let signature = "5d99b6f7f6d1f73d1a26497f2b1c89b24c0993913f86e9a2d02cd69887d9c94f3c880358579d811b21dd1b7fd9bb01c1d81d10e69f0384e675c32b39643be8921b";
let signByte = ByteBuffer.fromHex(signature, undefined, undefined);
let signBuffer = signByte.buffer;

let appArgs = [];
appArgs.push(new Uint8Array(Buffer.from(action)));  
appArgs.push(algosdk.encodeUint64(token_address));
appArgs.push(algosdk.encodeUint64(amount));
appArgs.push(new Uint8Array(Buffer.from(message)));
appArgs.push(new Uint8Array(Buffer.from(signBuffer)));

post by salman.haider on Jul 7, 2022

How can we define struct and enum - in Algorand?

such as :


enum TokenData {
  tokenVal,
  tokenBalance,
}

struct testInfo {
    address sender;
    TokenData data;  // defining enum into another structure
}

struct testConfig {
    address testToken;
    testInfo info;  // defining struct into another struct
}

// defining mapping based on the structs

mapping(address => testInfo) public testInfo;
mapping(address => testConfig) public testConfig;

How can we achieve the above mentioned in Algorand? I don’t see anything in Algorand?

post by salman.haider on Jul 7, 2022

Also how can we replicate the Shift operators of Solidity in Algorand?

1 . >> 2 . << 3 . &

Please provide relevant syntax in algorand

post by Ben on Jul 6, 2022

The bitwise operations in pyteal are detailed here: PyTeal Package — PyTeal documentation

for structs, there is nothing built in that will help with that yet.