sign method
Implementation
Authorization sign(Uint8List privateKey) {
final hash = signingHash();
final sig = RecoverableEcdsaSig.sign(hash, privateKey);
final sigR = _padTo32(sig.bytes.sublist(0, 32));
final sigS = _padTo32(sig.bytes.sublist(32, 64));
return Authorization(
chainId: chainId,
address: address,
nonce: nonce,
v: sig.recId,
r: sigR,
s: sigS,
);
}