(Delphi DLL) Working with PEM Encrypted Private Keys

Demonstrates how to load and save PEM encrypted private keys.

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

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, FileAccess, PrivateKey, Pem;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
pem: HCkPem;
pemPassword: PWideChar;
fac: HCkFileAccess;
pemText: PWideChar;
i: Integer;
numPrivateKeys: Integer;
privKey: HCkPrivateKey;

begin
success := False;

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

success := False;

pem := CkPem_Create();

pemPassword := 'secret';

// To load a PEM file containing encrypted private keys, simply
// provide the password.
success := CkPem_LoadPemFile(pem,'/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem',pemPassword);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPem__lastErrorText(pem));
    Exit;
  end;

fac := CkFileAccess_Create();
pemText := CkFileAccess__readEntireTextFile(fac,'/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem',pemPassword);

// To load a PEM from a string, call LoadPem instead of LoadPemFile:
success := CkPem_LoadPem(pem,pemText);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPem__lastErrorText(pem));
    Exit;
  end;

// A few notes:
// The PEM may contain both private keys and certificates (or anything else).
// The password is utilized for whatever content in the PEM is encrypted.  
// It is OK to have both encrypted and non-encrypted content within a given PEM.

// PEM private keys can be encrypted in different formats.  The LoadPem and LoadPemFile
// methods automatically handle the different formats.
// One format is PKCS8 and is indicated by this delimiter within the PEM:

// -----BEGIN ENCRYPTED PRIVATE KEY-----
// MIICoTAbBgkqhkiG9w0BBQMwDgQIfdD0zv24lgkCAggABIICgE0PdHJmRbNs6cBX
// ...

// Another format, we'll call "passphrase" looks like this in the PEM:
// -----BEGIN RSA PRIVATE KEY-----
// Proc-Type: 4,ENCRYPTED
// DEK-Info: DES-EDE3-CBC,A4215544D11C5D0C
// 
// paqy9XRexcSjurHfG0xhCaUD0HrvIdhuC0CbRxxxeMlkLaV6+uT80rBxt2AaibWG
// ...

// Show the bit length of each private key:

numPrivateKeys := CkPem_getNumPrivateKeys(pem);
if (numPrivateKeys = 0) then
  begin
    Memo1.Lines.Add(('Error: Expected the PEM to contain private keys.'));
    Exit;
  end;
privKey := CkPrivateKey_Create();
for i := 1 to numPrivateKeys do
  begin
    CkPem_PrivateKeyAt(pem,i - 1,privKey);
    Memo1.Lines.Add(IntToStr(i) + ': ' + IntToStr(CkPrivateKey_getBitLength(privKey)) + ' bits');
  end;

CkPem_Dispose(pem);
CkFileAccess_Dispose(fac);
CkPrivateKey_Dispose(privKey);

end;