Dart

Create Egypt ITIDA CAdES-BES Signature with Automatic JSON Canonicalization

See more Egypt ITIDA Examples

Demonstrates how to create a .p7s signature that fits Egypt's ITIDA requirements where Chilkat automatically does the ITIDA JSON canonicalization.

Note: This example requires Chilkat v9.5.0.75 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.

  final crypt = CkCrypt2();
  crypt.verboseLogging = true;

  final cert = CkCert();
  cert.verboseLogging = true;

  // Set the smart card PIN, which will be needed for signing.
  cert.smartCardPin = '12345678';

  // There are many ways to load the certificate.  
  // This example was created for a customer using an ePass2003 USB token.
  // Assuming the USB token is the only source of a hardware-based private key..
  try {
    cert.loadFromSmartcard('');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Tell the crypt class to use this cert.
  try {
    crypt.setSigningCert(cert);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final cmsOptions = CkJsonObject();
  // Setting "DigestData" causes OID 1.2.840.113549.1.7.5 (digestData) to be used.
  cmsOptions.updateBool('DigestData', true);
  cmsOptions.updateBool('OmitAlgorithmIdNull', true);

  // Indicate that we are passing normal JSON and we want Chilkat do automatically
  // do the ITIDA JSON canonicalization:
  cmsOptions.updateBool('CanonicalizeITIDA', true);

  crypt.cmsOptions = cmsOptions.emit();

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

  crypt.hashAlgorithm = 'sha256';

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

  // By default, all the certs in the chain of authentication are included in the signature.
  // If desired, we can choose to only include the signing certificate:
  crypt.includeCertChain = false;

  // Pass a JSON document such as the following.  Chilkat will do the ITIDA canonicalization.
  // (It is the canonicalized JSON that gets signed.)

  //       {
  //          "issuer":{
  //             "address":{
  //                "branchID":"0",
  //                "country":"EG",
  //                "regionCity":"Cairo",
  //                "postalCode":"",
  //                "buildingNumber":"0",
  //                "street":"123rd Street",
  //                "governate":"GOVERNATE"
  //             },
  //             "type":"B",
  //             "id":"209999899",
  //             "name":"Xyz SAE"
  //          },
  //          "receiver":{
  //             "address":{
  //                "country":"EG",
  //                "regionCity":"CAIRO",
  //                "postalCode":"11435",
  //                "buildingNumber":"0",
  //                "street":"Autostrad Road Abc",
  //                "governate":"GOVERNATE"
  //             },
  //             "type":"B",
  //             "id":"999999999",
  //             "name":"XYZ EGYPT FOR TRADE"
  //          },
  //          "documentType":"I",
  //          "documentTypeVersion":"1.0",
  //          "dateTimeIssued":"2020-11-15T11:04:53Z",
  //          "taxpayerActivityCode":"1073",
  //          "internalID":"ZZZZ999",
  //          "purchaseOrderReference":"2009199918",
  //          "salesOrderReference":"",
  //          "payment":{
  //             "bankName":"",
  //             "bankAddress":"",
  //             "bankAccountNo":"",
  //             "bankAccountIBAN":"",
  //             "swiftCode":"",
  //             "terms":""
  //          },
  //          "delivery":{
  //             "approach":"",
  //             "packaging":"",
  //             "dateValidity":"",
  //             "exportPort":"",
  //             "countryOfOrigin":"EG",
  //             "grossWeight":0,
  //             "netWeight":0,
  //             "terms":""
  //          },
  //          "invoiceLines":[
  //             {
  //                "description":"CDM Widget 48GX99X12BA",
  //                "itemType":"GS1",
  //                "itemCode":"7622213335056",
  //                "unitType":"CS",
  //                "quantity":1.00,
  //                "unitValue":{
  //                   "currencySold":"EGP",
  //                   "amountEGP":588.67,
  //                   "amountSold":0,
  //                   "currencyExchangeRate":0
  //                },
  //                "salesTotal":588.67,
  //                "total":603.97,
  //                "valueDifference":0,
  //                "totalTaxableFees":0,
  //                "netTotal":529.8,
  //                "itemsDiscount":0,
  //                "discount":{
  //                   "rate":10.00,
  //                   "amount":58.87
  //                },
  //                "taxableItems":[
  //                   {
  //                      "taxType":"T1",
  //                      "amount":74.17,
  //                      "subType":"No sub",
  //                      "rate":14.00
  //                   }
  //                ],
  //                "internalCode":"9099994"
  //             }
  //          ],
  //          "totalSales":588.67,
  //          "totalSalesAmount":588.67,
  //          "totalDiscountAmount":58.87,
  //          "netAmount":529.80,
  //          "taxTotals":[
  //             {
  //                "taxType":"T1",
  //                "amount":74.17
  //             }
  //          ],
  //          "extraDiscountAmount":0,
  //          "totalItemsDiscountAmount":0,
  //          "totalAmount":603.97,
  //       }
  // 

  final json = CkJsonObject();
  try {
    json.loadFile('qa_data/itida/sdk.invoicing.eta.gov.eg/files/one-doc.json');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  json.emitCompact = false;

  // Create the CAdES-BES signature.
  crypt.encodingMode = 'base64';

  // Make sure we sign the utf-8 byte representation of the JSON string
  crypt.charset = 'utf-8';

  final String sigBase64;
  try {
    sigBase64 = crypt.signStringENC(json.emit());
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Base64 signature:');
  print(sigBase64);

  // Add the signature to the JSON.
  json.updateString('signatures[0].signatureType', 'I');
  json.updateString('signatures[0].value', sigBase64);

  print('JSON with signature added:');
  print(json.emit());
}