Pascal (Lazarus/Delphi)
Create XML Digital Signature using Certificate on Smart Card

Demonstrates how to load a certificate located on a smart card or USB token and then use it for creating an XML digital signature such that the cryptographic signing happens on the smart card.
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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.Xml,
  Chilkat.StringBuilder,
  Chilkat.XmlDSigGen,
  Chilkat.Cert,
  Chilkat.ScMinidriver;

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

procedure RunDemo;
var
  success: Boolean;
  scmd: TScMinidriver;
  readerName: string;
  retval: Integer;
  certPart: string;
  partValue: string;
  cert: TCert;
  xml: TXml;
  gen: TXmlDSigGen;
  bUsePrivateKey: Boolean;
  sbXml: TStringBuilder;

begin
  success := False;

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

  scmd := TScMinidriver.Create;

  //  Reader names (smart card readers or USB tokens) can be discovered
  //  via List Readers or Find Smart Cards
  readerName := 'SCM Microsystems Inc. SCR33x USB Smart Card Reader 0';
  success := scmd.AcquireContext(readerName);
  if (success = False) then
    begin
      WriteLn(scmd.LastErrorText);
      Exit;
    end;

  //  If successful, the name of the currently inserted smart card is available:
  WriteLn('Card name: ' + scmd.CardName);

  //  If desired, perform regular PIN authentication with the smartcard.
  //  For more details about smart card PIN authentication, see the Smart Card PIN Authentication Example
  retval := scmd.PinAuthenticate('user','000000');
  if (retval <> 0) then
    begin
      WriteLn('PIN Authentication failed.');
    end;

  //  You can find a cerficate using any of the following certificate parts:
  //  "subjectDN" -- The full distinguished name of the cert.
  //  "subjectDN_withTags" -- Same as above, but in a format that includes the subject part tags, such as the "CN=" in "CN=something"
  //  "subjectCN" -- The common name part (CN) of the certificate's subject.
  //  "serial" -- The certificate serial number.
  //  "serial:issuerCN" -- The certificate serial number + the issuer's common name, delimited with a colon char.
  //  These are the same certificate parts that can be retrieved by listing certificates on the smart card (or USB token).
  //  See List Certificates on Smart Card Example
  certPart := 'subjectCN';
  partValue := 'PIVKey E42D60A759D39147A26E0AF2FB1183C5';

  //  If the certificate is found, it is loaded into the cert object.
  cert := TCert.Create;
  success := scmd.FindCert(certPart,partValue,cert);
  if (success = False) then
    begin
      WriteLn('Failed to find the certificate.');
      scmd.DeleteContext();
      Exit;
    end;

  WriteLn('Successfully loaded the cert object from the smart card / USB token.');

  //  Note: When successful, the cert object is internally linked to the ScMinidriver object's authenticated session.
  //  The cert object can now be used to sign or do other cryptographic operations that occur on the smart card / USB token.
  //  If your application calls PinDeauthenticate or DeleteContext, the cert will no longer be able to sign on the smart card
  //  because the smart card ScMinidriver session will no longer be authenticated or deleted.

  //  ------------------------------------------------------------------------------------------------------------
  //  We have the certificate.  Now let's do the XML digital signature..

  //  Create the following XML to be signed:

  //  <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
  //  <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
  //      <SOAP-ENV:Header>
  //          <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" SOAP-ENV:mustUnderstand="1"></wsse:Security>
  //      </SOAP-ENV:Header>
  //      <SOAP-ENV:Body xmlns:SOAP-SEC="http://schemas.xmlsoap.org/soap/security/2000-12" SOAP-SEC:id="Body">
  //          <z:FooBar xmlns:z="http://example.com" />
  //      </SOAP-ENV:Body>
  //  </SOAP-ENV:Envelope>

  xml := TXml.Create;
  xml.Tag := 'SOAP-ENV:Envelope';
  xml.AddAttribute('xmlns:SOAP-ENV','http://schemas.xmlsoap.org/soap/envelope/');
  xml.UpdateAttrAt('SOAP-ENV:Header|wsse:Security',True,'xmlns:wsse','http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd');
  xml.UpdateAttrAt('SOAP-ENV:Header|wsse:Security',True,'SOAP-ENV:mustUnderstand','1');
  xml.UpdateAttrAt('SOAP-ENV:Body',True,'xmlns:SOAP-SEC','http://schemas.xmlsoap.org/soap/security/2000-12');
  xml.UpdateAttrAt('SOAP-ENV:Body',True,'SOAP-SEC:id','Body');
  xml.UpdateAttrAt('SOAP-ENV:Body|z:FooBar',True,'xmlns:z','http://example.com');

  //  Prepare for signing...
  gen := TXmlDSigGen.Create;

  //  Indicate where the Signature will be inserted.
  gen.SigLocation := 'SOAP-ENV:Envelope|SOAP-ENV:Header|wsse:Security';

  //  Add a reference to the fragment of the XML to be signed.

  //  Note: "Body" refers to the XML element having an "id" equal to "Body", where "id" is case insensitive
  //  and where any namespace might qualify the attribute.  In this case, the SOAP-ENV:Body fragment is signed
  //  NOT because the tag = "Body", but because it has SOAP-SEC:id="Body"
  gen.AddSameDocRef('Body','sha1','EXCL_C14N','','');

  //  (You can read about the SignedInfoPrefixList in the online reference documentation.  It's optional..)
  gen.SignedInfoPrefixList := 'wsse SOAP-ENV';

  //  Provide the private key for signing via the certificate, and indicate that
  //  we want the base64 of the certificate embedded in the KeyInfo.
  gen.KeyInfoType := 'X509Data';
  gen.X509Type := 'Certificate';

  //  Note: Our certificate was loaded from the smartcard and is internally linked to the authenticated ScMinidriver session.
  //  The signing will occur on the smart card using the chosen certificate.
  bUsePrivateKey := True;
  success := gen.SetX509Cert(cert,bUsePrivateKey);
  if (success <> True) then
    begin
      WriteLn(gen.LastErrorText);
      Exit;
    end;

  //  Everything's specified.  Now create and insert the Signature
  sbXml := TStringBuilder.Create;
  xml.GetXmlSb(sbXml);
  success := gen.CreateXmlDSigSb(sbXml);
  if (success <> True) then
    begin
      WriteLn(gen.LastErrorText);
      Exit;
    end;

  //  Examine the XML with the digital signature inserted
  WriteLn(sbXml.GetAsString());

  //  ------------------------------------------------------------------------------------------------------------
  //  Cleanup our ScMinidriver session...

  //  When finished with operations that required authentication, you may if you wish, deauthenticate the session.
  success := scmd.PinDeauthenticate('user');
  if (success = False) then
    begin
      WriteLn(scmd.LastErrorText);
    end;

  //  Delete the context when finished with the card.
  success := scmd.DeleteContext();
  if (success = False) then
    begin
      WriteLn(scmd.LastErrorText);
    end;


  scmd.Free;
  cert.Free;
  xml.Free;
  gen.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.