sign method
Implementation
Transaction sign(String privateKey) {
var k = SHA3(256, KECCAK_PADDING, 256);
k.update(this._createProtoTxData().writeToBuffer());
Uint8List messageHash = Uint8List.fromList(k.digest());
crypto.MsgSignature msgSignature =
crypto.sign(messageHash, crypto.hexToBytes(privateKey));
final header = msgSignature.v & 0xFF;
var recId = header - 27;
Uint8List signature = AppHelpers.concat([
AppHelpers.bigIntToBytes(msgSignature.r),
AppHelpers.bigIntToBytes(msgSignature.s),
Uint8List.fromList([recId])
]);
this.signature = signature;
return this;
}