Auth
import org.web3j.crypto.Credentials;
import org.web3j.crypto.Sign;
import org.web3j.utils.Numeric;
import java.nio.charset.StandardCharsets;
public class CryptoUtils {
public static String createSign(String message, String privateKey) {
Credentials credentials = Credentials.create(privateKey);
byte[] hash = message.getBytes(StandardCharsets.UTF_8);
Sign.SignatureData signatureData = Sign.signPrefixedMessage(hash, credentials.getEcKeyPair());
String r = Numeric.toHexString(signatureData.getR());
String s = Numeric.toHexString(signatureData.getS()).substring(2);
String v = Numeric.toHexString(signatureData.getV()).substring(2);
return r + s + v;
}
}Last updated