@Override
 public byte[] sign(byte[] message) throws GeneralSecurityException {
 try {
 String encoded = Base64.getEncoder().encodeToString(message);
 System.out.println(encoded);;
 
 // Create SHA-256 MessageDigest instance
 MessageDigest sha256Digest = MessageDigest.getInstance("SHA256");
 
 // Hash the input message
 byte[] hashedMessage = sha256Digest.digest(message);
 Digest digest = Digest.newBuilder().setSha256(ByteString.copyFrom(hashedMessage)).build();
 // Set the GCP credentials
 KeyManagementServiceSettings settings = KeyManagementServiceSettings.newBuilder()
 .build();
 try (KeyManagementServiceClient client = KeyManagementServiceClient.create(settings)) {
 AsymmetricSignResponse response = client.asymmetricSign(keyId, digest);
 return response.getSignature().toByteArray();
 }
 } catch (Exception e) {
 throw new GeneralSecurityException("Error while signing PDF", e);
 }
 }