Dart

Swift Alliance LAU XML Signature

See more XML Digital Signatures Examples

Calculating the LAU for Swift Alliance File Act XML using HMAC SHA256. (The XML signature, also referred to as Local Authentication (LAU), is computed using the algorithm HMAC based on SHA-256.) 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.

  // We begin with the following XML:

  // <?xml version="1.0" encoding="UTF-8"?>
  // <Saa:DataPDU xmlns:Saa="urn:swift:saa:xsd:saa.2.0" xmlns:Sw="urn:swift:snl:ns.Sw" xmlns:SwInt="urn:swift:snl:ns.SwInt" xmlns:SwGbl="urn:swift:snl:ns.SwGbl" xmlns:SwSec="urn:swift:snl:ns.SwSec">
  //     <Saa:Revision>2.0.6</Saa:Revision>
  //     <Saa:Header>
  //         <Saa:Message>
  //             <Saa:SenderReference>Ref760FA1234</Saa:SenderReference>
  //             <Saa:MessageIdentifier>tsrv.fin.mt7xx.gteesstandbys</Saa:MessageIdentifier>
  //             <Saa:Format>File</Saa:Format>
  //             <Saa:SubFormat>Input</Saa:SubFormat>
  //             <Saa:Sender>
  //                 <Saa:DN>cn=su8,o=ptsqgbbb,o=swift</Saa:DN>
  //                 <Saa:FullName>
  //                     <Saa:X1>PTSQGBBBXXX</Saa:X1>
  //                 </Saa:FullName>
  //             </Saa:Sender>
  //             <Saa:Receiver>
  //                 <Saa:DN>cn=abc,ou=saa,o=xxx,o=swift</Saa:DN>
  //                 <Saa:FullName>
  //                     <Saa:X1>PTSXXXXXXXX</Saa:X1>
  //                     <Saa:X2>saa</Saa:X2>
  //                 </Saa:FullName>
  //             </Saa:Receiver>
  //             <Saa:InterfaceInfo>
  //                 <Saa:UserReference>CRE...</Saa:UserReference>
  //                 <Saa:MessageCreator>ApplicationInterface</Saa:MessageCreator>
  //                 <Saa:MessageContext>Original</Saa:MessageContext>
  //                 <Saa:MessageNature>Financial</Saa:MessageNature>
  //             </Saa:InterfaceInfo>
  //             <Saa:NetworkInfo>
  //                 <Saa:Priority>Normal</Saa:Priority>
  //                 <Saa:IsPossibleDuplicate>true</Saa:IsPossibleDuplicate>
  //                 <Saa:Service>swift.corp.fast!x</Saa:Service>
  //                 <Saa:Network>Application</Saa:Network>
  //                 <Saa:SessionNr>0080</Saa:SessionNr>
  //                 <Saa:SeqNr>000001</Saa:SeqNr>
  //                 <Saa:SWIFTNetNetworkInfo>
  //                     <Saa:RequestType>tsrv.fin.mt7xx.gteesstandbys</Saa:RequestType>
  //                     <Saa:Reference>2f949999-d32e-49eb-9999-9a819b9b9c0d</Saa:Reference>
  //                     <Saa:FileInfo>SwCompression=Zip</Saa:FileInfo>
  //                 </Saa:SWIFTNetNetworkInfo>
  //             </Saa:NetworkInfo>
  //             <Saa:SecurityInfo>
  //                 <Saa:SWIFTNetSecurityInfo>
  //                     <Saa:FileDigestAlgorithm>SHA-256</Saa:FileDigestAlgorithm>
  //                     <Saa:FileDigestValue>9tnnjIgsowPSU+ehm8Rb0J5TvZIvhCYnySzFkpur1aw=</Saa:FileDigestValue>
  //                 </Saa:SWIFTNetSecurityInfo>
  //             </Saa:SecurityInfo>
  //             <Saa:FileLogicalName>Payload.ZIP</Saa:FileLogicalName>
  //             <Saa:ExpiryDateTime>20210712074808</Saa:ExpiryDateTime>
  //         </Saa:Message>
  //     </Saa:Header>
  //     <Saa:Body>Payload.ZIP</Saa:Body>
  // </Saa:DataPDU>

  // Load the XML file to be signed.
  final sbXml = CkStringBuilder();
  try {
    sbXml.loadFile('c:/someDir/fileToSign.xml', 'utf-8');
  } on ChilkatException {
    print('Failed to load XML file.');
    return;
  }

  // We need to add a "LAU" XML element just before the "</Saa:DataPDU>"
  final numReplaced = sbXml.replace('</Saa:DataPDU>', '<LAU xmlns="urn:swift:saa:xsd:saa.2.0"></LAU></Saa:DataPDU>');

  final gen = CkXmlDSigGen();
  gen.sigLocation = 'Saa:DataPDU|LAU';
  gen.sigLocationMod = 0;
  gen.sigNamespacePrefix = 'ds';
  gen.sigNamespaceUri = 'http://www.w3.org/2000/09/xmldsig#';
  gen.signedInfoCanonAlg = 'EXCL_C14N';
  gen.signedInfoDigestMethod = 'sha256';
  gen.behaviors = 'CompactSignedXml';

  // Sign the entire document.
  gen.addSameDocRef('', 'sha256', 'EXCL_C14N', '', '');

  // Set our HMAC key
  gen.setHmacKey('Abcdef0123456789Abcdef0123456789', 'ascii');

  // Sign the XML:
  try {
    gen.createXmlDSigSb(sbXml);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Examine the signed XML
  print(sbXml.getAsString());

  // Save the signed XML to a file.
  sbXml.writeFile('c:/someDir/signedFile.xml', 'utf-8', false);
}