extern "C" __declspec( dllimport ) __stdcall int EP_ProtectedStringByKey( char* Key, char* Buffer, int Len);

function EP_ProtectedStringByKey(Key : PAnsiChar; Buffer : pointer; Len : integer) : integer; stdcall;

Public Declare Function EP_ProtectedStringByKey Lib "enigma_ide.dll" (ByVal Key As String, ByVal Str As String, ByVal Length As Byte) As Byte

public class Enigma_IDE
{
    [DllImport("enigma_ide.dll", CallingConvention = CallingConvention.StdCall)]
    public static extern Int32 EP_ProtectedStringByKey(string Key, IntPtr Buffer, Int32 Len);
}

uses 
  enigma_ide; // the module contains a definitions of Enigma API

procedure TForm1.FormShow(Sender: TObject);
var
  str : shortstring;
  len : byte;
  arr : array [0..MAX_STRING_SIZE - 1] of char;
  buflen : integer;
  buf : pointer;
begin
  // This method shows how to get protected string with using shortstring type
  len := EP_ProtectedStringByKey('fyi6z02Y', @str[1], sizeof(str));
  if len > 0 then
  begin
    str[0] := char(len);
    Edit1.Text := str;
  end;
  // This method show how to get string with char array
  ZeroMemory(@arr, sizeof(arr));
  if EP_ProtectedStringByID(1, @arr, sizeof(arr)) > 0 then
  begin
    Edit2.Text := arr;
  end;
  // This method gets string length and allocs buffer for the string
  buflen := EP_ProtectedStringByKey('26Lu66Er', nil, 0);
  if buflen > 0 then
  begin
    GetMem(buf, buflen + 1); // one byte is reserved for #0 symbol (like string terminator)
    ZeroMemory(buf, buflen + 1);
    if EP_ProtectedStringByKey('26Lu66Er', buf, buflen) > 0 then
    begin
      Edit3.Text := PAnsiChar(buf);
    end;
    FreeMem(buf);
  end;
end;

public class Enigma_IDE
{
    public static string EP_ProtectedStringByKeyAsAnsiString(string Key)
    {
        Int32 len = EP_ProtectedStringByKey(Key, IntPtr.Zero, 0);
        if (len > 0)
        {
            byte[] buffer = new byte[len];
            if (EP_ProtectedStringByKey(Key, Marshal.UnsafeAddrOfPinnedArrayElement(buffer, 0), len) > 0)
            {
                return Encoding.ASCII.GetString(buffer);
            }
        }
        return string.Empty;
    }
    public static string EP_ProtectedStringByKeyAsWideString(string Key)
    {
        Int32 len = EP_ProtectedStringByKey(Key, IntPtr.Zero, 0);
        if (len > 0)
        {
            byte[] buffer = new byte[len];
            if (EP_ProtectedStringByKey(Key, Marshal.UnsafeAddrOfPinnedArrayElement(buffer, 0), len) > 0)
            {
                return Encoding.Unicode.GetString(buffer);
            }
        }
        return string.Empty;
    }
}


private void Form1_Shown(object sender, EventArgs e)
{
    textBox1.Text = Enigma_IDE.EP_ProtectedStringByKeyAsAnsiString("fyi6z02Y");
    textBox2.Text = Enigma_IDE.EP_ProtectedStringByKeyAsWideString("26Lu66Er");
}

Private Sub Form_Load()
Dim Lenght As Byte
Dim Str As String

Length = EP_ProtectedStringByKey("fyi6z02Y", vbNullString, 0)
Str = String$(Length, 0)
If EP_ProtectedStringByKey("fyi6z02Y", Str, Length) > 0 Then
  Text1.Text = Str
End If

Length = EP_ProtectedStringByID(1, vbNullString, 0)
Str = String$(Length, 0)
If EP_ProtectedStringByID(1, Str, Length) > 0 Then
  Text2.Text = Str
End If

Length = EP_ProtectedStringByKey("26Lu66Er", vbNullString, 0)
Str = String$(Length, 0)
If EP_ProtectedStringByKey("26Lu66Er", Str, Length) > 0 Then
  Text3.Text = Str
End If