(Delphi DLL) Sign a File to Create a .p7s (Detached Signature)

Delphi DLL example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

Note: This example requires Chilkat v10.1.2 or greater.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, JsonObject, Cert, CertStore, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: HCkCrypt2;
signingCertSubject: PWideChar;
pfxFilename: PWideChar;
pfxPassword: PWideChar;
certStore: HCkCertStore;
success: Boolean;
jsonCN: HCkJsonObject;
cert: HCkCert;
inFile: PWideChar;
sigFile: PWideChar;

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

crypt := CkCrypt2_Create();

// Use a digital certificate and private key from a PFX file (.pfx or .p12).
signingCertSubject := 'Acme Inc';
pfxFilename := '/Users/chilkat/testData/pfx/acme.pfx';
pfxPassword := 'test123';

certStore := CkCertStore_Create();
success := CkCertStore_LoadPfxFile(certStore,pfxFilename,pfxPassword);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCertStore__lastErrorText(certStore));
    Exit;
  end;

jsonCN := CkJsonObject_Create();
CkJsonObject_UpdateString(jsonCN,'CN',signingCertSubject);

cert := CkCert_Create();
success := CkCertStore_FindCert(certStore,jsonCN,cert);
if (success = False) then
  begin
    Memo1.Lines.Add('Failed to find certificate by subject common name.');
    Exit;
  end;

// Tell the crypt component to use this cert.
success := CkCrypt2_SetSigningCert(crypt,cert);

// We can sign any type of file, creating a .p7s as output:
inFile := '/Users/chilkat/testData/pdf/sample.pdf';
sigFile := '/Users/chilkat/testData/p7s/sample.p7s';

success := CkCrypt2_CreateP7S(crypt,inFile,sigFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

success := CkCrypt2_VerifyP7S(crypt,inFile,sigFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

Memo1.Lines.Add('Success!');

CkCrypt2_Dispose(crypt);
CkCertStore_Dispose(certStore);
CkJsonObject_Dispose(jsonCN);
CkCert_Dispose(cert);

end;