Encryption plugin

Program create;
{$APPTYPE CONSOLE}

uses
  Sysutils,Firebird,Windows;

var
st : IStatus;
master : IMaster;
util : IUtil;
dpb : IXpbBuilder;
prov : IProvider;
att : IAttachment;
tra : ITransaction;

procedure PrintError(s : IStatus);
var
maxMessage : Integer;
outMessage : PAnsiChar;
begin
maxMessage := 256;
outMessage := PAnsiChar(StrAlloc(maxMessage));
util.formatStatus(outMessage, maxMessage, s);
writeln(outMessage);
StrDispose(outMessage);
end;

type
IKeyCallback = class(ICryptKeyCallbackImpl)
function callback(dataLength: Cardinal; data: Pointer; bufferLength: Cardinal; buffer: Pointer): Cardinal; override;
end;

function IKeyCallback.callback(dataLength: Cardinal; data: Pointer; bufferLength: Cardinal; buffer: Pointer): Cardinal;
var Key: PAnsiChar;
    KeyLength:Integer;
begin
  KeyLength := 0;
If (bufferLength > 0) and (buffer <> nil) then
begin
    WriteLn('Sending key');
    Key := '0123456789';
    KeyLength := Length(Key);
    WriteLn('got key request: ', PAnsiChar(Data):dataLength);
    Move(Key^, buffer^, KeyLength);
end;
Result := KeyLength;
end;

var param1:String;

begin
  if ParamCount>0 then
  begin
    param1 := ParamStr(1);
  end;
  if param1<>'open' then
    param1 := 'create';

WriteLn('starting...('+param1+')');
master := fb_get_master_interface;
if master = nil then
     begin
      WriteLn('master is nil');
      Exit;
     end;
    Write('getting util interface...');
    util := master.getUtilInterface;
    WriteLn('done.');

    Write('getting status and dispatcher...');
st := master.getStatus;
prov := master.getDispatcher;
    WriteLn('done.');
if (util = nil) or (st = nil) or (prov = nil) then
begin
WriteLn('null pointers');
Exit;
end;

try
prov.setDbCryptCallback(st, IKeyCallback.create);
Write('Generating DPB...');
//create DPB
dpb := util.getXpbBuilder(st, IXpbBuilder.DPB, nil, 0);
Write('page size...');
dpb.insertInt(st, isc_dpb_page_size, 4 * 1024);
Write('user name...');
dpb.insertString(st, isc_dpb_user_name, 'sysdba');
Write('password...');
dpb.insertString(st, isc_dpb_password, 'masterkey');
WriteLn('done.');

    //create empty database
    if param1='create' then
    begin
att := prov.createDatabase(st, 'fbtests.fdb', dpb.getBufferLength(st), dpb.getBuffer(st));
writeln ('Database fbtests.fdb created');

      //start transaction
      tra := att.startTransaction(st, 0, nil);

      //Encrypt database
      att.execute(st, tra, 0, 'alter database encrypt with aes128', 3,
        nil, nil, nil, nil); // Input parameters and output data not used

      //commit transaction (will close interface)
      tra.commit(st);
      tra := nil;

      WriteLn('Press Enter to continue');
      ReadLn;

      //detach from database
      att.detach(st);
      att := nil;

      //remove unneeded tag from DPB
      if dpb.findFirst(st, isc_dpb_page_size)
        then dpb.removeCurrent(st);

      //attach once again
      att := prov.attachDatabase(st, 'fbtests.fdb', dpb.getBufferLength(st), dpb.getBuffer(st));
      writeln ('Re-attached database fbtests.fdb');

      //start transaction
      tra := att.startTransaction(st, 0, nil);

      //create table
      att.execute(st, tra, 0, 'create table dates_table (d1 date)', 3,
        nil, nil, nil, nil); // Input parameters and output data not used

      //commit transaction retaining
      tra.commitRetaining(st);
      writeln ('Table dates_table created');

      //insert a record into dates_table
      att.execute(st, tra, 0, 'insert into dates_table values (CURRENT_DATE)', 3,
        nil, nil, nil, nil); // Input parameters and output data not used

      //commit transaction (will close interface)
      tra.commit(st);
      tra := nil;

      writeln ('Record inserted into dates_table');
    end

    //open database
    else if param1='open' then
    begin
      att := prov.attachDatabase(st, 'fbtests.fdb', dpb.getBufferLength(st), dpb.getBuffer(st));
      writeln ('Database fbtests.fdb Opened');
      exit;
    end;

//detach from the database (will close interface)
att.detach(st);
att := nil;

dpb.dispose;
dpb := nil;
except
on e: FbException do PrintError(e.getStatus);
end;

prov.release;
end.

type
  IKeyCallback = class(ICryptKeyCallbackImpl)
  private
    fKey : String;
    function callback(dataLength: Cardinal; data: Pointer; bufferLength: Cardinal; buffer: Pointer): Cardinal; override;
  end;


function IKeyCallback.callback(dataLength: Cardinal; data: Pointer; bufferLength: Cardinal; buffer: Pointer): Cardinal;
Var b:TBytes;
begin
  b:=TEncoding.ASCII.GetBytes(fKey);
  If (bufferLength > 0) and (buffer <> nil) then begin
    Result := Length(b);
    Move(b[0],buffer^,Result);
  end else
    Result := 0;
end;
{
function TFXClientLibrary.Call_attach_database(Const db_name,db_crypt_key:String;Const db_handle:PISC_DB_HANDLE;Const parm_buffer_length:FXShort;Const parm_buffer:PFXByte): ISC_STATUS;
Var key:IKeyCallback;
    cb:Pointer ABSOLUTE key;
    lDBN:FXShort;
    sDBN:TBytes;
Begin
  sDBN := TEncoding.Convert(TEncoding.Default, TEncoding.ANSI, BytesOf(db_name));
  lDBN := length(sDBN);

  if (db_crypt_key<>EmptyStr)and(Assigned(fdatabase_crypt_callback)) then Begin
    key:=IKeyCallback.create;key.fKey:=db_crypt_key;
Result:=fdatabase_crypt_callback(@fStatusVector,cb);
    if Result>0 Then
      Exit;
    end;

  Result:=fisc_attach_database( @fStatusVector,
                                   lDBN,
                                   PFXByte(sDBN),
                                   db_handle,
                                   parm_buffer_length,
                                   parm_buffer
                                   );
  // key is released
end;

CryptKey key;
ICryptKeyCallback* cb = &key;
fb_database_crypt_callback(status, cb);

CryptKey key;
fb_database_crypt_callback(status, &key);

CryptKey key;

typedef ISC_STATUS(__stdcall *p_fb_database_crypt_callback)(ISC_STATUS*, void*);

extern "C"
int __declspec(dllexport) SetKey1(char *szkey, int len )
{
    ICryptKeyCallback* cb = &key;
    HMODULE hGDS32 = NULL;
    p_fb_database_crypt_callback pSetCallback = NULL;

    strncpy_s(szKey, szkey, len);
    szKey[len] = NULL;

    try
    {
        ISC_STATUS status;
        ISC_STATUS statusArray[20];

        hGDS32 = LoadLibraryA("gds32.dll");
        if(hGDS32==NULL)
            return -2;

        pSetCallback = (p_fb_database_crypt_callback)GetProcAddress(hGDS32, "fb_database_crypt_callback");
        if (pSetCallback == NULL)
            throw "GetProcAddress error";

        status = pSetCallback(statusArray, (void*)cb);
        char szMsg[64],szRet[16];

        //strcpy_s(szMsg, "fb_database_crypt_callback returned ");
        //_itoa_s(status, szRet, 10);
        //strcat_s(szMsg,szRet);
        //MessageBoxA(NULL, szMsg, "SetColor", MB_OK);

        FreeLibrary(hGDS32);

        return (int)status;
    }
    catch (...)
    {
        if(hGDS32) FreeLibrary(hGDS32);
        return -1;
    }
}