docs: public static byte[] signWithSha1RSA(byte[] dataToSign,
              PrivateKey privateKey) throws InvalidKeyException {
          Signature signature;
          try {
              signature = Signature.getInstance("SHA1withRSA");
              signature.initSign(privateKey, srand);
              signature.update(dataToSign);
              return signature.sign();
          } catch (NoSuchAlgorithmException e) {
              throw new IllegalStateException(e);
          } catch (SignatureException e) {
              throw new IllegalStateException(e);
          }
      }