(Delphi DLL) ConvertToSignedPk

Demonstrates how to digitally sign MIME to create an "opaque" signature. The MIME is converted to an application/x-pkcs7-mime which is a PKCS7 signature that includes both the original MIME message and the signature. This is different than AddDetachedSignaturePk, where the signature is appended to the MIME. This example demonstrates how to use the certificate and its corresponding private key when they are stored in separate files -- a .cer for the certificate, and a .pem for the private key.

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, Mime, PrivateKey, Cert;

...

procedure TForm1.Button1Click(Sender: TObject);
var
mime: HCkMime;
cert: HCkCert;
success: Boolean;
privKey: HCkPrivateKey;

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

mime := CkMime_Create();

// Load the certificate from a .cer file.
cert := CkCert_Create();
success := CkCert_LoadFromFile(cert,'aaworkarea/myCert.cer');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// Load the private key from an encrypted PEM file.
// (A private key can be loaded from other file formats also..)
privKey := CkPrivateKey_Create();
success := CkPrivateKey_LoadEncryptedPemFile(privKey,'aaworkarea/myPrivateKey.pem','myPassword');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

success := CkMime_SetBodyFromPlainText(mime,'This is the plain-text MIME body.');

// Convert the MIME to application/x-pkcs7-mime, which
// is PKCS7 containing both the original content and the signature.
success := CkMime_ConvertToSignedPk(mime,cert,privKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    Exit;
  end;

// Save the S/MIME to a file.
success := CkMime_SaveMime(mime,'aaworkarea/opaqueSignedMime.txt');
if (success = False) then
  begin
    Memo1.Lines.Add(CkMime__lastErrorText(mime));
    Exit;
  end;

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

CkMime_Dispose(mime);
CkCert_Dispose(cert);
CkPrivateKey_Dispose(privKey);

end;