(Delphi ActiveX) Convert Java KeyStore to PKCS12 / PFX

Loads a Java keystore file and saves it as a PKCS12 / PFX. A Java keystore (JKS) can contain two types of entries: (1) trusted root certificates or (2) private keys + cert chains. Usually a JKS will contain all entries of one type or another (and thus a particular JKS serves one purpose or another; meaning that a JKS containing trusted roots is used as a source for verifying pre-trusted roots, and a JKS containing private keys (and cert chains) is used as a secure, encrypted store for private keys).

A PKCS12 / PFX typically contains one or more private keys, along with each private key's certificate chain. Therefore, it typically makes sense to only write the private key entries to a PKCS12 (and the associated certificate chains). If a JKS contains trusted root certificates, it makes more sense to conver it to a PEM file (such as the CA cert bundle in PEM format from mozilla.org).

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
jks: TChilkatJavaKeyStore;
jksPassword: WideString;
success: Integer;
pkcs12: TChilkatPfx;
numPrivateKeys: Integer;
i: Integer;
privKey: IPrivateKey;
certChain: IChilkatCertChain;
pkcs12Password: WideString;

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

jks := TChilkatJavaKeyStore.Create(Self);

jksPassword := 'myJksPassword';

// Load the Java keystore from a file.  The JKS file password is used
// to verify the keyed digest that is found at the very end of the keystore.
// It verifies that the keystore has not been modified.
success := jks.LoadFile(jksPassword,'/someDir/keyStore.jks');
if (success <> 1) then
  begin
    Memo1.Lines.Add(jks.LastErrorText);
    Exit;
  end;

// To convert, we'll access the private key entries
// from the JKS, add each to the PKCS12, and then save the PKCS12.
pkcs12 := TChilkatPfx.Create(Self);

numPrivateKeys := jks.NumPrivateKeys;

// For each private key entry, get the private key and
// the associated certificate chain.
// Each private key is password protected.  Usually it is the same
// password as used for the keyed digest of the entire JKS.  
// However, this does not have to be.  The password is passed
// here to handle the possibility of each private key requiring
// a different password.
i := 0;
while i < numPrivateKeys do
  begin
    privKey := jks.GetPrivateKey(jksPassword,i);
    Memo1.Lines.Add(jks.GetPrivateKeyAlias(i));
    certChain := jks.GetCertChain(i);

    // Add the private key and it's associated certificate chain to the PKCS12.
    success := pkcs12.AddPrivateKey(privKey,certChain);
    if (success <> 1) then
      begin
        Memo1.Lines.Add(pkcs12.LastErrorText);

        Exit;
      end;

    i := i + 1;
  end;

// Save the PKCS12 / PFX to a file.
// The password can be the same as the JKS password, or something new.
// (With the PKCS12 format, there is a single password for the entire contents
// of the file.  With the JKS format, there is flexibility in allowing each private key
// to have it's own password.)
pkcs12Password := 'myNewPassword';
success := pkcs12.ToFile(pkcs12Password,'/pkcs12_files/myPfx.p12');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pkcs12.LastErrorText);
  end
else
  begin
    Memo1.Lines.Add('Successfully saved to PKCS12 format.');
  end;
end;