Dart

Canonicalize XML Fragment

See more XML Digital Signatures Examples

Demonstrates how to canonicalize a fragment of an XML document. The fragment is identified by the element having an Id attribute equal to a specified value. (The Id attribute can have any namespace, and the attribute name is case-insensitive (thus "ID", "Id", "id", etc. match). 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 http = CkHttp();
  final sbXml = CkStringBuilder();
  final canon = CkXmlDSig();

  // Use exclusive XML canonicalization.
  final canonVersion = 'EXCL_C14N';
  final withComments = false;
  // The optional inclusive namespaces prefix list if using exclusive canonicalization.
  final prefixList = '';

  final url = 'https://www.chilkatsoft.com/exampleData/canonicalizeFragmentTest.xml';
  http.quickGetSb(url, sbXml);

  // This is the input XML:

  // <?xml version="1.0" encoding="UTF-8"?>
  // <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
  // <SignedInfo>
  //   <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
  //   <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
  //   <Reference URI="#object">
  //     <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
  //     <DigestValue>OPnpF/ZNLDxJ/I+1F3iHhlmSwgo=</DigestValue>
  //   </Reference>
  // </SignedInfo>
  // <SignatureValue>nihUFQg4mDhLgecvhIcKb9Gz8VRTOlw+adiZOBBXgK4JodEe5aFfCqm8WcRIT8GL
  // LXSk8PsUP4//SsKqUBQkpotcAqQAhtz2v9kCWdoUDnAOtFZkd/CnsZ1sge0ndha4
  // 0wWDV+nOWyJxkYgicvB8POYtSmldLLepPGMz+J7/Uws=</SignatureValue>
  // <KeyInfo>
  //   <KeyValue>
  //     <RSAKeyValue>
  //       <Modulus>4IlzOY3Y9fXoh3Y5f06wBbtTg94Pt6vcfcd1KQ0FLm0S36aGJtTSb6pYKfyX7PqC
  //       UQ8wgL6xUJ5GRPEsu9gyz8ZobwfZsGCsvu40CWoT9fcFBZPfXro1Vtlh/xl/yYHm
  //       +Gzqh0Bw76xtLHSfLfpVOrmZdwKmSFKMTvNXOFd0V18=</Modulus>
  //       <Exponent>AQAB</Exponent>
  //     </RSAKeyValue>
  //   </KeyValue>
  // </KeyInfo>
  // <Object Id="object">some text
  //   with spaces and CR-LF.</Object>
  // </Signature>

  // Canonicalize and return the fragment of XML starting at the element where the Id attribute equals "object".
  final xmlCanonFrag = canon.canonicalizeFragment(sbXml.getAsString(), 'object', canonVersion, prefixList, withComments);
  print(xmlCanonFrag);

  // The output is:
  // 
  // <Object xmlns="http://www.w3.org/2000/09/xmldsig#" Id="object">some text
  //   with spaces and CR-LF.</Object>
  // 
}