verifyHash method
Verify the signature from in SHA256 hashed data
Implementation
bool verifyHash(Uint8List sha256Data, SteemPublicKey publicKey) {
var q = publicKey.q;
final signer = ECDSASigner(null, HMac(SHA256Digest(), 64));
signer.init(false, PublicKeyParameter(ECPublicKey(q, SteemKey.secp256k1)));
return signer.verifySignature(sha256Data, ecSig);
}