(Delphi ActiveX) Duplicate OpensSSL Command that Decrypts Binary DER

This example duplicates the following:

openssl smime -decrypt -in INPUT_FILE -inform der -binary -out OUTPUT_FILE -recip PEM_CERT_AND_KEY -passin pass:PRIVKEY_PASSWORD

Note: Although "smime" is the OpenSSL command, we're not really dealing with S/MIME. The arguments "-inform der -binary" indicate that the input is simply the binary DER (i.e. the PKCS7 binary encrypted object). The output can be any type of file (whatever was encrypted).

Note: This example requires Chilkat v11.0.0 or greater.

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
crypt: TChilkatCrypt2;
pem: TChilkatPem;
privkey: TPrivateKey;
cert: TChilkatCert;

begin
success := 0;

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

crypt := TChilkatCrypt2.Create(Self);

crypt.CryptAlgorithm := 'pki';

pem := TChilkatPem.Create(Self);
success := pem.LoadPemFile('qa_data/pem/myPem.pem','password');
if (success = 0) then
  begin
    Memo1.Lines.Add(pem.LastErrorText);
    Exit;
  end;

privkey := TPrivateKey.Create(Self);
success := pem.PrivateKeyAt(0,privkey.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pem.LastErrorText);
    Exit;
  end;

cert := TChilkatCert.Create(Self);
success := pem.CertAt(0,cert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(pem.LastErrorText);
    Exit;
  end;

success := crypt.SetDecryptCert2(cert.ControlInterface,privkey.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

success := crypt.CkDecryptFile('qa_data/infile.enc','qa_output/outfile.dat');
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

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