(Delphi ActiveX) Export Digital Certificate's Public Key

The ExportPublicKey method can be called to get a certificate's public key. It can then be saved to any of a number of formats: (1) OpenSSL DER, (2) OpenSSL PEM, (3) RSA DER, (4) XML.

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
cert: TChilkatCert;
success: Integer;
pubkey: IPublicKey;

begin
cert := TChilkatCert.Create(Self);

// LoadFromFile will load virtually any certificate format file.
// It will auto-recognize the format and load appropiately.
success := cert.LoadFromFile('/Users/chilkat/testData/cer/chilkat.cer');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// Get the public key:

pubkey := cert.ExportPublicKey();
if (cert.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// Save to various formats:
success := pubkey.SaveDerFile(0,'/Users/chilkat/testData/pubkeys/chilkat_pkcs8.der');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pubkey.LastErrorText);

    Exit;
  end;

success := pubkey.SavePemFile(0,'/Users/chilkat/testData/pubkeys/chilkat.pem');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pubkey.LastErrorText);

    Exit;
  end;

success := pubkey.SaveDerFile(1,'/Users/chilkat/testData/pubkeys/chilkat_pkcs1.der');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pubkey.LastErrorText);

    Exit;
  end;

success := pubkey.SaveXmlFile('/Users/chilkat/testData/pubkeys/chilkat.xml');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pubkey.LastErrorText);

    Exit;
  end;

Memo1.Lines.Add('Public key exported to all file formats.');
end;