(Delphi DLL) 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 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, PublicKey;

...

procedure TForm1.Button1Click(Sender: TObject);
var
cert: HCkCert;
success: Boolean;
pubkey: HCkPublicKey;

begin
cert := CkCert_Create();

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

// Get the public key:

pubkey := CkCert_ExportPublicKey(cert);
if (CkCert_getLastMethodSuccess(cert) = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// Save to various formats:
success := CkPublicKey_SaveDerFile(pubkey,False,'/Users/chilkat/testData/pubkeys/chilkat_pkcs8.der');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubkey));
    CkPublicKey_Dispose(pubkey);
    Exit;
  end;

success := CkPublicKey_SavePemFile(pubkey,False,'/Users/chilkat/testData/pubkeys/chilkat.pem');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubkey));
    CkPublicKey_Dispose(pubkey);
    Exit;
  end;

success := CkPublicKey_SaveDerFile(pubkey,True,'/Users/chilkat/testData/pubkeys/chilkat_pkcs1.der');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubkey));
    CkPublicKey_Dispose(pubkey);
    Exit;
  end;

success := CkPublicKey_SaveXmlFile(pubkey,'/Users/chilkat/testData/pubkeys/chilkat.xml');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubkey));
    CkPublicKey_Dispose(pubkey);
    Exit;
  end;

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

CkCert_Dispose(cert);

end;