Delphi DLL

Duplicate openssl pkcs12 –export –in certfile.cer –inkey certfile.key –out certfile.pfx

See more OpenSSL Examples

How to create a PKCS12 (.p12 or .pfx) from a certificate file and private key file: Demonstrates how to duplicate this OpenSSL command:

Duplicate openssl pkcs12 –export –in certfile.cer –inkey certfile.key –out certfile.pfx

Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Pfx, PrivateKey, CertChain, Cert;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
pkey: HCkPrivateKey;
cert: HCkCert;
certChain: HCkCertChain;
pfx: HCkPfx;
password: PWideChar;

begin
success := False;

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

pkey := CkPrivateKey_Create();

// Load the private key from the file.
success := CkPrivateKey_LoadAnyFormatFile(pkey,'certFile.key','');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(pkey));
    Exit;
  end;

cert := CkCert_Create();
// The LoadFromFile method auto-recognizes the format...
success := CkCert_LoadFromFile(cert,'certfile.cer');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// We'll need a cert chain object to create the PKCS12, so get it
// from the cert.  

certChain := CkCert_GetCertChain(cert);
if (not CkCert_getLastMethodSuccess(cert)) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// Create the PFX object, add the cert and private key, and write to a .pfx file.
pfx := CkPfx_Create();

// The cert(s) are automatically added in the call to AddPrivateKey
success := CkPfx_AddPrivateKey(pfx,pkey,certChain);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPfx__lastErrorText(pfx));
    Exit;
  end;

// Write the .pfx to a file.
password := 'myPassword';
success := CkPfx_ToFile(pfx,password,'certfile.pfx');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPfx__lastErrorText(pfx));
    Exit;
  end;

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

CkPrivateKey_Dispose(pkey);
CkCert_Dispose(cert);
CkPfx_Dispose(pfx);

end;