Pascal (Lazarus/Delphi)

Create Enveloping XML Digital Signature

See more XML Digital Signatures Examples

This example creates an enveloping digital signature.
An enveloping signature is where the signed data is contained within the Signature within an Object element.
This example signs non-XML text data where the XML signature constitutes the entire output. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.XmlDSigGen,
  Chilkat.Zip,
  Chilkat.StringBuilder,
  Chilkat.BinData,
  Chilkat.PrivateKey,
  Chilkat.ZipEntry,
  Chilkat.Http;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  zipFile: TBinData;
  keyUrl: string;
  zip: TZip;
  entry: TZipEntry;
  ecKey: TPrivateKey;
  gen: TXmlDSigGen;
  sbContent: TStringBuilder;
  sbXml: TStringBuilder;

begin
  success := False;

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

  //  Let's use the ECDSA private key at https://www.chilkatsoft.com/exampleData/secp256r1-key.zip
  //  for signing.
  http := THttp.Create;
  zipFile := TBinData.Create;
  keyUrl := 'https://www.chilkatsoft.com/exampleData/secp256r1-key.zip';

  success := http.QuickGetBd(keyUrl,zipFile);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  zip := TZip.Create;
  success := zip.OpenBd(zipFile);

  entry := TZipEntry.Create;
  success := zip.EntryMatching('*.pem',entry);
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  ecKey := TPrivateKey.Create;
  success := ecKey.LoadPem(entry.UnzipToString(0,'utf-8'));
  if (success <> True) then
    begin
      WriteLn(ecKey.LastErrorText);
      Exit;
    end;

  //  ----------------------------------------------------------------------------
  gen := TXmlDSigGen.Create;

  //  Provide the ECDSA key to the XML Digital Signature generator
  gen.SetPrivateKey(ecKey);

  //  Add an enveloped reference to the content to be signed.
  sbContent := TStringBuilder.Create;
  sbContent.Append('This is the content that is signed.');
  gen.AddEnvelopedRef('abc123',sbContent,'sha256','C14N','');

  //  Generate the XML digital signature.
  //  Notice that in other examples, the sbXml passed to CreateXmlDSigSb
  //  already contains XML, and the XML signature is inserted at the location
  //  specified by the SigLocation property.  In this case, both SigLocation
  //  and sbXml are empty.  The result is that sbXml will contain just the Signature.
  sbXml := TStringBuilder.Create;
  success := gen.CreateXmlDSigSb(sbXml);
  if (success = False) then
    begin
      WriteLn(gen.LastErrorText);
      Exit;
    end;

  //  Examine the enveloped signature, where the data is contained within the XML Signature
  WriteLn(sbXml.GetAsString());

  //  The Signature returned is compact and in a single line, like this:
  //  <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256"/><ds:Reference URI="#abc123"><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>tEVrbXXjeTXjF3tIojul4/sgeEGN49E1dxr/GMs8GNE=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>/pILUshwrzgdGc4bPgp85TDfbUiM9pn8EIPNRVWKuoVEtPsv4XRthUrv9aDDvajmyl2okLwTakANgtaxO1ULMw==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:ECKeyValue xmlns="http://www.w3.org/2009/xmldsig11#"><ds:NamedCurve URI="urn:oid:1.2.840.10045.3.1.7" /><ds:PublicKey>BOVKaiLPKEDChhkA64UEBOXTv/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=</ds:PublicKey></ds:ECKeyValue></ds:KeyValue></ds:KeyInfo><ds:Object Id="abc123">This is the content that is signed.</ds:Object></ds:Signature>

  //  XML pretty-printed, the signature is as follows, but pretty-printing introductes whitespace that breaks the signature..

  //  <?xml version="1.0" encoding="utf-8" ?>
  //  <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
  //      <ds:SignedInfo>
  //          <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
  //          <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256" />
  //          <ds:Reference URI="#abc123">
  //              <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" />
  //              <ds:DigestValue>tEVrbXXjeTXjF3tIojul4/sgeEGN49E1dxr/GMs8GNE=</ds:DigestValue>
  //          </ds:Reference>
  //      </ds:SignedInfo>
  //      <ds:SignatureValue>/pILUshwrzgdGc4bPgp85TDfbUiM9pn8EIPNRVWKuoVEtPsv4XRthUrv9aDDvajmyl2okLwTakANgtaxO1ULMw==</ds:SignatureValue>
  //      <ds:KeyInfo>
  //          <ds:KeyValue>
  //              <ds:ECKeyValue xmlns="http://www.w3.org/2009/xmldsig11#">
  //                  <ds:NamedCurve URI="urn:oid:1.2.840.10045.3.1.7" />
  //                  <ds:PublicKey>BOVKaiLPKEDChhkA64UEBOXTv/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=</ds:PublicKey>
  //              </ds:ECKeyValue>
  //          </ds:KeyValue>
  //      </ds:KeyInfo>
  //      <ds:Object Id="abc123">This is the content that is signed.</ds:Object>
  //  </ds:Signature>
  //  


  http.Free;
  zipFile.Free;
  zip.Free;
  entry.Free;
  ecKey.Free;
  gen.Free;
  sbContent.Free;
  sbXml.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.