Dart

Convert PDF to pdf.p7s (Digitally Signed)

See more CAdES Examples

Demonstrates how to convert a PDF into a .p7s file that contains the PDF within a PKCS7 signature (the .p7s format). 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.

  // -----------------------------------------------------------------
  // Note: This is case where the .p7s extension is used where the .p7m extension
  // is technically more appropriate.
  // See .p7s vs .p7m file extension
  // -----------------------------------------------------------------

  final crypt = CkCrypt2();

  final cert = CkCert();
  try {
    cert.loadPfxFile('qa_data/pfx/cert_test123.pfx', 'test123');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Tell the crypt component to use this cert.
  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';

  // We can sign any type of file, creating a .p7s as output.
  // The .p7s contains the signature and also embeds the data of the file that is signed.
  final inFile = 'qa_data/pdf/sample.pdf';
  final p7sFile = 'qa_output/sample.pdf.p7s';

  // -----------------------------------------------------------------------------------------
  // Also see Chilkat's online tool to examine a .p7m and generate code to duplicate the .p7m
  // -----------------------------------------------------------------------------------------

  // Create the CAdES-BES attached signature, which contains the original data.
  // Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
  // is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
  // is NOT contained within the signature.  We want the data to be contained in the signature, therefore
  // we call CreateP7M even though we are naming our output file .p7s.
  try {
    crypt.createP7M(inFile, p7sFile);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Verify the .p7s file and extract the original file from the .p7s. 
  final extractedToFilePath = 'qa_output/sample.pdf';
  try {
    crypt.verifyP7M(p7sFile, extractedToFilePath);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success!');
}