ink_env::ecdsa_recover is not returning the right public key

Question

I am having an issue trying to verify ecdsa signature in ink! for my test.

I am generating the signature this way

const keyring = new Keyring({type: 'ecdsa'});
const pair =  keyring.addFromUri('//Alice');

Then i get the public key to be stored in the contract storage as the governor during instantiation of the contract

const publicKey = pair.publicKey;

This is how i am signing the message(data)

const sig = Array.from(pair.sign(hashDataArray));

Then i pass the signature into the contract.

But when i call ink_env::ecdsa_recover in the contract to recover the public key from the signature, i get a different public key entirely different from the one i stored(generated) in the contract during instantiation.

Answer 1

So I figured the signature creation in polkadotJS is to receive the raw data and not the hash.

More so, I had to generate the public key this way:

const mnemonic = mnemonicGenerate();
const keyring = new Keyring({type: 'ethereum'});
const pair = keyring.addFromUri(mnemonic, { name: 'first pair' }, 'ethereum');
      
const publicKey = pair.publicKey;

And then i created the signature this way

const sig = Array.from(pair.sign(rawData));

With this generation, I was able to recover the public key successfully with ink_env::ecdsa_recover

N.B: I am using keccak256 for hashing. The Keyring type ecdsa uses blake2 for hashing hence why I used the type ethereum which uses keccak for hashing. You can find the details here