Dart Requires Chilkat v10.1.2+

Sign a File to Create a .p7s (Detached Signature)

See more Encryption Examples

_LANGUAGE_ example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename. Dart

import 'package:chilkat/chilkat.dart';

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

  final crypt = CkCrypt2();

  // Use a digital certificate and private key from a PFX file (.pfx or .p12).
  final signingCertSubject = 'Acme Inc';
  final pfxFilename = '/Users/chilkat/testData/pfx/acme.pfx';
  final pfxPassword = 'test123';

  final certStore = CkCertStore();
  try {
    certStore.loadPfxFile(pfxFilename, pfxPassword);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final jsonCN = CkJsonObject();
  jsonCN.updateString('CN', signingCertSubject);

  final cert = CkCert();
  try {
    certStore.findCert(jsonCN, cert);
  } on ChilkatException {
    print('Failed to find certificate by subject common name.');
    return;
  }

  // Tell the crypt component to use this cert.
  crypt.setSigningCert(cert);

  // We can sign any type of file, creating a .p7s as output:
  final inFile = '/Users/chilkat/testData/pdf/sample.pdf';
  final sigFile = '/Users/chilkat/testData/p7s/sample.p7s';

  try {
    crypt.createP7S(inFile, sigFile);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    crypt.verifyP7S(inFile, sigFile);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success!');
}