(Delphi DLL) 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 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, Pfx, JavaKeyStore, PrivateKey, CertChain;

...

procedure TForm1.Button1Click(Sender: TObject);
var
jks: HCkJavaKeyStore;
jksPassword: PWideChar;
success: Boolean;
pkcs12: HCkPfx;
numPrivateKeys: Integer;
i: Integer;
privKey: HCkPrivateKey;
certChain: HCkCertChain;
pkcs12Password: PWideChar;

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

jks := CkJavaKeyStore_Create();

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 := CkJavaKeyStore_LoadFile(jks,jksPassword,'/someDir/keyStore.jks');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkJavaKeyStore__lastErrorText(jks));
    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 := CkPfx_Create();

numPrivateKeys := CkJavaKeyStore_getNumPrivateKeys(jks);

// 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 := CkJavaKeyStore_GetPrivateKey(jks,jksPassword,i);
    Memo1.Lines.Add(CkJavaKeyStore__getPrivateKeyAlias(jks,i));
    certChain := CkJavaKeyStore_GetCertChain(jks,i);

    // Add the private key and it's associated certificate chain to the PKCS12.
    success := CkPfx_AddPrivateKey(pkcs12,privKey,certChain);
    if (success <> True) then
      begin
        Memo1.Lines.Add(CkPfx__lastErrorText(pkcs12));
        CkCertChain_Dispose(certChain);
        CkPrivateKey_Dispose(privKey);
        Exit;
      end;

    CkCertChain_Dispose(certChain);
    CkPrivateKey_Dispose(privKey);
    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 := CkPfx_ToFile(pkcs12,pkcs12Password,'/pkcs12_files/myPfx.p12');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPfx__lastErrorText(pkcs12));
  end
else
  begin
    Memo1.Lines.Add('Successfully saved to PKCS12 format.');
  end;

CkJavaKeyStore_Dispose(jks);
CkPfx_Dispose(pkcs12);

end;