(Delphi DLL) Sign a File to Create a .p7m File (using a PFX)

Delphi DLL example to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M.

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, Cert, CertStore, Crypt2;

...

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

cert := CkCertStore_FindCertBySubjectCN(certStore,signingCertSubject);
if (CkCertStore_getLastMethodSuccess(certStore) = 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 .p7m as output:
inFile := '/Users/chilkat/testData/pdf/sample.pdf';
outputFile := '/Users/chilkat/testData/p7m/sample.pdf.p7m';
success := CkCrypt2_CreateP7M(crypt,inFile,outputFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    CkCert_Dispose(cert);
    Exit;
  end;

// Verify and restore the original file:
success := CkCrypt2_SetVerifyCert(crypt,cert);

inFile := outputFile;
outputFile := '/Users/chilkat/testData/pdf/restored.pdf';

success := CkCrypt2_VerifyP7M(crypt,inFile,outputFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    CkCert_Dispose(cert);
    Exit;
  end;

CkCert_Dispose(cert);

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

CkCrypt2_Dispose(crypt);
CkCertStore_Dispose(certStore);

end;