Pascal (Lazarus/Delphi)

Working with PEM Encrypted Private Keys

See more PEM Examples

Demonstrates how to load and save PEM encrypted private keys. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.FileAccess,
  Chilkat.PrivateKey,
  Chilkat.Pem;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  pem: TPem;
  pemPassword: string;
  fac: TFileAccess;
  pemText: string;
  i: Integer;
  numPrivateKeys: Integer;
  privKey: TPrivateKey;

begin
  success := False;

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

  success := False;

  pem := TPem.Create;

  pemPassword := 'secret';

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

  fac := TFileAccess.Create;
  pemText := fac.ReadEntireTextFile('/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem',pemPassword);

  //  To load a PEM from a string, call LoadPem instead of LoadPemFile:
  success := pem.LoadPem(pemText);
  if (success = False) then
    begin
      WriteLn(pem.LastErrorText);
      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 := pem.NumPrivateKeys;
  if (numPrivateKeys = 0) then
    begin
      WriteLn(('Error: Expected the PEM to contain private keys.'));
      Exit;
    end;
  privKey := TPrivateKey.Create;
  for i := 1 to numPrivateKeys do
    begin
      pem.PrivateKeyAt(i - 1,privKey);
      WriteLn(i + ': ' + privKey.BitLength + ' bits');
    end;



  pem.Free;
  fac.Free;
  privKey.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.