Dart

Create CAdES p7m using AWS KMS to Sign in the Cloud

See more Signing in the Cloud Examples

Demonstrates how to create a CAdES p7m, using AWS KMS. The signing of the hash happens in the Cloud on AWS KMS. Everything else regarding the creation of CAdES happens locally within Chilkat.

Note: This example requires Chilkat v9.5.0.96 or greater.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // Load the certificate used for signing.  The certificate's private key is stored in AWS KMS
  // However, we still need the certificate locally (without private key).
  final cert = CkCert();
  try {
    cert.loadFromFile('qa_data/certs/myCert.cer');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Here's a screenshot showing the key ID of a private key in AWS KMS:
  // (image:https://example-code.com/images/aws_kms.jpg/endImage)

  // To sign using AWS KMS, 
  // add the following lines of code to specify your AWS authentication credentials,
  // and the ID of the KMS private key.
  final jsonAwsKms = CkJsonObject();
  // Set the "service" equal to "aws_kms" to tell Chilkat to use AWS KMS for signing.
  jsonAwsKms.updateString('service', 'aws_kms');
  jsonAwsKms.updateString('access_key', 'ACCESS_KEY');
  jsonAwsKms.updateString('secret_key', 'SECRET_KEY');
  // Make sure to specify the correct region for your case.
  jsonAwsKms.updateString('region', 'us-west-2');
  // In the above screenshot, our key ID is "187012e8-008f-4fc7-b100-5efe6146dff2".  You will use your key ID.
  jsonAwsKms.updateString('key_id', '187012e8-008f-4fc7-b100-5efe6146dff2');

  cert.setCloudSigner(jsonAwsKms);

  final crypt = CkCrypt2();

  try {
    crypt.setSigningCert(cert);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The CadesEnabled property applies to all methods that create PKCS7 signatures. 
  // To create a CAdES-BES signature, set this property equal to true.
  crypt.cadesEnabled = true;

  crypt.hashAlgorithm = 'sha256';

  final signedAttrs = CkJsonObject();
  signedAttrs.updateInt('contentType', 1);
  signedAttrs.updateInt('signingTime', 1);
  signedAttrs.updateInt('messageDigest', 1);
  signedAttrs.updateInt('signingCertificateV2', 1);
  crypt.signingAttributes = signedAttrs.emit();

  // You can sign any type of file..
  final inputXmlPath = 'qa_data/e-Invoice.xml';
  final outputP7mPath = 'qa_output/signed.p7m';

  // Create the CAdES-BES attached signature, which contains the original data.
  // Chilkat will build the .p7m locally, but will (internally) use ARSS
  // to do the RSA signing remotely.
  try {
    crypt.createP7M(inputXmlPath, outputP7mPath);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success.');
}