1 files changed, 1009 insertions, 0 deletions
diff --git a/phpBB/phpbb/captcha/plugins/qa.php b/phpBB/phpbb/captcha/plugins/qa.php
new file mode 100644
index 0000000000..a7ba994cc3
--- /dev/null
+++ b/phpBB/phpbb/captcha/plugins/qa.php
@@ -0,0 +1,1009 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\captcha\plugins;
+
+/**
+* And now to something completely different. Let's make a captcha without extending the abstract class.
+* QA CAPTCHA sample implementation
+*/
+class qa
+{
+	var $confirm_id;
+	var $answer;
+	var $question_ids;
+	var $question_text;
+	var $question_lang;
+	var $question_strict;
+	var $attempts = 0;
+	var $type;
+	// dirty trick: 0 is false, but can still encode that the captcha is not yet validated
+	var $solved = 0;
+
+	protected $table_captcha_questions;
+	protected $table_captcha_answers;
+	protected $table_qa_confirm;
+
+	/**
+	* @var string name of the service.
+	*/
+	protected $service_name;
+
+	/**
+	* Constructor
+	*
+	* @param string $table_captcha_questions
+	* @param string $table_captcha_answers
+	* @param string $table_qa_confirm
+	*/
+	function __construct($table_captcha_questions, $table_captcha_answers, $table_qa_confirm)
+	{
+		$this->table_captcha_questions = $table_captcha_questions;
+		$this->table_captcha_answers = $table_captcha_answers;
+		$this->table_qa_confirm = $table_qa_confirm;
+	}
+
+	/**
+	* @param int $type  as per the CAPTCHA API docs, the type
+	*/
+	function init($type)
+	{
+		global $config, $db, $user;
+
+		// load our language file
+		$user->add_lang('captcha_qa');
+
+		// read input
+		$this->confirm_id = request_var('qa_confirm_id', '');
+		$this->answer = utf8_normalize_nfc(request_var('qa_answer', '', true));
+
+		$this->type = (int) $type;
+		$this->question_lang = $user->lang_name;
+
+		// we need all defined questions - shouldn't be too many, so we can just grab them
+		// try the user's lang first
+		$sql = 'SELECT question_id
+			FROM ' . $this->table_captcha_questions . "
+			WHERE lang_iso = '" . $db->sql_escape($user->lang_name) . "'";
+		$result = $db->sql_query($sql, 3600);
+
+		while ($row = $db->sql_fetchrow($result))
+		{
+			$this->question_ids[$row['question_id']] = $row['question_id'];
+		}
+		$db->sql_freeresult($result);
+
+		// fallback to the board default lang
+		if (!sizeof($this->question_ids))
+		{
+			$this->question_lang = $config['default_lang'];
+
+			$sql = 'SELECT question_id
+				FROM ' . $this->table_captcha_questions . "
+				WHERE lang_iso = '" . $db->sql_escape($config['default_lang']) . "'";
+			$result = $db->sql_query($sql, 7200);
+
+			while ($row = $db->sql_fetchrow($result))
+			{
+				$this->question_ids[$row['question_id']] = $row['question_id'];
+			}
+			$db->sql_freeresult($result);
+		}
+
+		// okay, if there is a confirm_id, we try to load that confirm's state. If not, we try to find one
+		if (!$this->load_answer() && (!$this->load_confirm_id() || !$this->load_answer()))
+		{
+			// we have no valid confirm ID, better get ready to ask something
+			$this->select_question();
+		}
+	}
+
+	/**
+	* See if the captcha has created its tables.
+	*/
+	public function is_installed()
+	{
+		global $db;
+
+		$db_tool = new \phpbb\db\tools($db);
+
+		return $db_tool->sql_table_exists($this->table_captcha_questions);
+	}
+
+	/**
+	*  API function - for the captcha to be available, it must have installed itself and there has to be at least one question in the board's default lang
+	*/
+	public function is_available()
+	{
+		global $config, $db, $phpbb_root_path, $phpEx, $user;
+
+		// load language file for pretty display in the ACP dropdown
+		$user->add_lang('captcha_qa');
+
+		if (!$this->is_installed())
+		{
+			return false;
+		}
+
+		$sql = 'SELECT COUNT(question_id) AS question_count
+			FROM ' . $this->table_captcha_questions . "
+			WHERE lang_iso = '" . $db->sql_escape($config['default_lang']) . "'";
+		$result = $db->sql_query($sql);
+		$row = $db->sql_fetchrow($result);
+		$db->sql_freeresult($result);
+
+		return ((bool) $row['question_count']);
+	}
+
+	/**
+	*  API function
+	*/
+	function has_config()
+	{
+		return true;
+	}
+
+	/**
+	*  API function
+	*/
+	static public function get_name()
+	{
+		return 'CAPTCHA_QA';
+	}
+
+	/**
+	* @return string the name of the service corresponding to the plugin
+	*/
+	function get_service_name()
+	{
+		return $this->service_name;
+	}
+
+	/**
+	* Set the name of the plugin
+	*
+	* @param string $name
+	*/
+	public function set_name($name)
+	{
+		$this->service_name = $name;
+	}
+
+	/**
+	*  API function - not needed as we don't display an image
+	*/
+	function execute_demo()
+	{
+	}
+
+	/**
+	*  API function - not needed as we don't display an image
+	*/
+	function execute()
+	{
+	}
+
+	/**
+	*  API function - send the question to the template
+	*/
+	function get_template()
+	{
+		global $template;
+
+		if ($this->is_solved())
+		{
+			return false;
+		}
+		else
+		{
+			$template->assign_vars(array(
+				'QA_CONFIRM_QUESTION'		=> $this->question_text,
+				'QA_CONFIRM_ID'				=> $this->confirm_id,
+				'S_CONFIRM_CODE'			=> true,
+				'S_TYPE'					=> $this->type,
+			));
+
+			return 'captcha_qa.html';
+		}
+	}
+
+	/**
+	*  API function - we just display a mockup so that the captcha doesn't need to be installed
+	*/
+	function get_demo_template()
+	{
+		global $config, $db, $template;
+
+		if ($this->is_available())
+		{
+			$sql = 'SELECT question_text
+				FROM ' . $this->table_captcha_questions . "
+				WHERE lang_iso = '" . $db->sql_escape($config['default_lang']) . "'";
+			$result = $db->sql_query_limit($sql, 1);
+			if ($row = $db->sql_fetchrow($result))
+			{
+				$template->assign_vars(array(
+					'QA_CONFIRM_QUESTION'		=> $row['question_text'],
+				));
+			}
+			$db->sql_freeresult($result);
+		}
+		return 'captcha_qa_acp_demo.html';
+	}
+
+	/**
+	*  API function
+	*/
+	function get_hidden_fields()
+	{
+		$hidden_fields = array();
+
+		// this is required - otherwise we would forget about the captcha being already solved
+		if ($this->solved)
+		{
+			$hidden_fields['qa_answer'] = $this->answer;
+		}
+		$hidden_fields['qa_confirm_id'] = $this->confirm_id;
+
+		return $hidden_fields;
+	}
+
+	/**
+	*  API function
+	*/
+	function garbage_collect($type = 0)
+	{
+		global $db, $config;
+
+		$sql = 'SELECT c.confirm_id
+			FROM ' . $this->table_qa_confirm . ' c
+			LEFT JOIN ' . SESSIONS_TABLE . ' s
+				ON (c.session_id = s.session_id)
+			WHERE s.session_id IS NULL' .
+				((empty($type)) ? '' : ' AND c.confirm_type = ' . (int) $type);
+		$result = $db->sql_query($sql);
+
+		if ($row = $db->sql_fetchrow($result))
+		{
+			$sql_in = array();
+
+			do
+			{
+				$sql_in[] = (string) $row['confirm_id'];
+			}
+			while ($row = $db->sql_fetchrow($result));
+
+			if (sizeof($sql_in))
+			{
+				$sql = 'DELETE FROM ' . $this->table_qa_confirm . '
+					WHERE ' . $db->sql_in_set('confirm_id', $sql_in);
+				$db->sql_query($sql);
+			}
+		}
+		$db->sql_freeresult($result);
+	}
+
+	/**
+	*  API function - we don't drop the tables here, as that would cause the loss of all entered questions.
+	*/
+	function uninstall()
+	{
+		$this->garbage_collect(0);
+	}
+
+	/**
+	*  API function - set up shop
+	*/
+	function install()
+	{
+		global $db;
+
+		$db_tool = new \phpbb\db\tools($db);
+
+		$tables = array($this->table_captcha_questions, $this->table_captcha_answers, $this->table_qa_confirm);
+
+		$schemas = array(
+				$this->table_captcha_questions		=> array (
+					'COLUMNS' => array(
+						'question_id'	=> array('UINT', null, 'auto_increment'),
+						'strict'		=> array('BOOL', 0),
+						'lang_id'		=> array('UINT', 0),
+						'lang_iso'		=> array('VCHAR:30', ''),
+						'question_text'	=> array('TEXT_UNI', ''),
+					),
+					'PRIMARY_KEY'		=> 'question_id',
+					'KEYS'				=> array(
+						'lang'			=> array('INDEX', 'lang_iso'),
+					),
+				),
+				$this->table_captcha_answers		=> array (
+					'COLUMNS' => array(
+						'question_id'	=> array('UINT', 0),
+						'answer_text'	=> array('STEXT_UNI', ''),
+					),
+					'KEYS'				=> array(
+						'qid'			=> array('INDEX', 'question_id'),
+					),
+				),
+				$this->table_qa_confirm		=> array (
+					'COLUMNS' => array(
+						'session_id'	=> array('CHAR:32', ''),
+						'confirm_id'	=> array('CHAR:32', ''),
+						'lang_iso'		=> array('VCHAR:30', ''),
+						'question_id'	=> array('UINT', 0),
+						'attempts'		=> array('UINT', 0),
+						'confirm_type'	=> array('USINT', 0),
+					),
+					'KEYS'				=> array(
+						'session_id'			=> array('INDEX', 'session_id'),
+						'lookup'				=> array('INDEX', array('confirm_id', 'session_id', 'lang_iso')),
+					),
+					'PRIMARY_KEY'		=> 'confirm_id',
+				),
+		);
+
+		foreach($schemas as $table => $schema)
+		{
+			if (!$db_tool->sql_table_exists($table))
+			{
+				$db_tool->sql_create_table($table, $schema);
+			}
+		}
+	}
+
+	/**
+	*  API function - see what has to be done to validate
+	*/
+	function validate()
+	{
+		global $config, $db, $user;
+
+		$error = '';
+
+		if (!sizeof($this->question_ids))
+		{
+			return false;
+		}
+
+		if (!$this->confirm_id)
+		{
+			$error = $user->lang['CONFIRM_QUESTION_WRONG'];
+		}
+		else
+		{
+			if ($this->check_answer())
+			{
+				$this->solved = true;
+			}
+			else
+			{
+				$error = $user->lang['CONFIRM_QUESTION_WRONG'];
+			}
+		}
+
+		if (strlen($error))
+		{
+			// okay, incorrect answer. Let's ask a new question.
+			$this->new_attempt();
+			$this->solved = false;
+
+			return $error;
+		}
+		else
+		{
+			return false;
+		}
+	}
+
+	/**
+	*  Select a question
+	*/
+	function select_question()
+	{
+		global $db, $user;
+
+		if (!sizeof($this->question_ids))
+		{
+			return false;
+		}
+		$this->confirm_id = md5(unique_id($user->ip));
+		$this->question = (int) array_rand($this->question_ids);
+
+		$sql = 'INSERT INTO ' . $this->table_qa_confirm . ' ' . $db->sql_build_array('INSERT', array(
+			'confirm_id'	=> (string) $this->confirm_id,
+			'session_id'	=> (string) $user->session_id,
+			'lang_iso'		=> (string) $this->question_lang,
+			'confirm_type'	=> (int) $this->type,
+			'question_id'	=> (int) $this->question,
+		));
+		$db->sql_query($sql);
+
+		$this->load_answer();
+	}
+
+	/**
+	* New Question, if desired.
+	*/
+	function reselect_question()
+	{
+		global $db, $user;
+
+		if (!sizeof($this->question_ids))
+		{
+			return false;
+		}
+
+		$this->question = (int) array_rand($this->question_ids);
+		$this->solved = 0;
+
+		$sql = 'UPDATE ' . $this->table_qa_confirm . '
+			SET question_id = ' . (int) $this->question . "
+			WHERE confirm_id = '" . $db->sql_escape($this->confirm_id) . "'
+				AND session_id = '" . $db->sql_escape($user->session_id) . "'";
+		$db->sql_query($sql);
+
+		$this->load_answer();
+	}
+
+	/**
+	* Wrong answer, so we increase the attempts and use a different question.
+	*/
+	function new_attempt()
+	{
+		global $db, $user;
+
+		// yah, I would prefer a stronger rand, but this should work
+		$this->question = (int) array_rand($this->question_ids);
+		$this->solved = 0;
+
+		$sql = 'UPDATE ' . $this->table_qa_confirm . '
+			SET question_id = ' . (int) $this->question . ",
+				attempts = attempts + 1
+			WHERE confirm_id = '" . $db->sql_escape($this->confirm_id) . "'
+				AND session_id = '" . $db->sql_escape($user->session_id) . "'";
+		$db->sql_query($sql);
+
+		$this->load_answer();
+	}
+
+
+	/**
+	* See if there is already an entry for the current session.
+	*/
+	function load_confirm_id()
+	{
+		global $db, $user;
+
+		$sql = 'SELECT confirm_id
+			FROM ' . $this->table_qa_confirm . "
+			WHERE
+				session_id = '" . $db->sql_escape($user->session_id) . "'
+				AND lang_iso = '" . $db->sql_escape($this->question_lang) . "'
+				AND confirm_type = " . $this->type;
+		$result = $db->sql_query_limit($sql, 1);
+		$row = $db->sql_fetchrow($result);
+		$db->sql_freeresult($result);
+
+		if ($row)
+		{
+			$this->confirm_id = $row['confirm_id'];
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	* Look up everything we need and populate the instance variables.
+	*/
+	function load_answer()
+	{
+		global $db, $user;
+
+		if (!strlen($this->confirm_id) || !sizeof($this->question_ids))
+		{
+			return false;
+		}
+
+		$sql = 'SELECT con.question_id, attempts, question_text, strict
+			FROM ' . $this->table_qa_confirm . ' con, ' . $this->table_captcha_questions . " qes
+			WHERE con.question_id = qes.question_id
+				AND confirm_id = '" . $db->sql_escape($this->confirm_id) . "'
+				AND session_id = '" . $db->sql_escape($user->session_id) . "'
+				AND qes.lang_iso = '" . $db->sql_escape($this->question_lang) . "'
+				AND confirm_type = " . $this->type;
+		$result = $db->sql_query($sql);
+		$row = $db->sql_fetchrow($result);
+		$db->sql_freeresult($result);
+
+		if ($row)
+		{
+			$this->question = $row['question_id'];
+
+			$this->attempts = $row['attempts'];
+			$this->question_strict = $row['strict'];
+			$this->question_text = $row['question_text'];
+
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	*  The actual validation
+	*/
+	function check_answer()
+	{
+		global $db;
+
+		$answer = ($this->question_strict) ? utf8_normalize_nfc(request_var('qa_answer', '', true)) : utf8_clean_string(utf8_normalize_nfc(request_var('qa_answer', '', true)));
+
+		$sql = 'SELECT answer_text
+			FROM ' . $this->table_captcha_answers . '
+			WHERE question_id = ' . (int) $this->question;
+		$result = $db->sql_query($sql);
+
+		while ($row = $db->sql_fetchrow($result))
+		{
+			$solution = ($this->question_strict) ? $row['answer_text'] : utf8_clean_string($row['answer_text']);
+
+			if ($solution === $answer)
+			{
+				$this->solved = true;
+
+				break;
+			}
+		}
+		$db->sql_freeresult($result);
+
+		return $this->solved;
+	}
+
+	/**
+	*  API function
+	*/
+	function get_attempt_count()
+	{
+		return $this->attempts;
+	}
+
+	/**
+	*  API function
+	*/
+	function reset()
+	{
+		global $db, $user;
+
+		$sql = 'DELETE FROM ' . $this->table_qa_confirm . "
+			WHERE session_id = '" . $db->sql_escape($user->session_id) . "'
+				AND confirm_type = " . (int) $this->type;
+		$db->sql_query($sql);
+
+		// we leave the class usable by generating a new question
+		$this->select_question();
+	}
+
+	/**
+	*  API function
+	*/
+	function is_solved()
+	{
+		if (request_var('qa_answer', false) && $this->solved === 0)
+		{
+			$this->validate();
+		}
+
+		return (bool) $this->solved;
+	}
+
+	/**
+	*  API function - The ACP backend, this marks the end of the easy methods
+	*/
+	function acp_page($id, &$module)
+	{
+		global $db, $user, $auth, $template;
+		global $config, $phpbb_root_path, $phpbb_admin_path, $phpEx;
+
+		$user->add_lang('acp/board');
+		$user->add_lang('captcha_qa');
+
+		if (!self::is_installed())
+		{
+			$this->install();
+		}
+
+		$module->tpl_name = 'captcha_qa_acp';
+		$module->page_title = 'ACP_VC_SETTINGS';
+		$form_key = 'acp_captcha';
+		add_form_key($form_key);
+
+		$submit = request_var('submit', false);
+		$question_id = request_var('question_id', 0);
+		$action = request_var('action', '');
+
+		// we have two pages, so users might want to navigate from one to the other
+		$list_url = $module->u_action . "&amp;configure=1&amp;select_captcha=" . $this->get_service_name();
+
+		$template->assign_vars(array(
+			'U_ACTION'		=> $module->u_action,
+			'QUESTION_ID'	=> $question_id ,
+			'CLASS'			=> $this->get_service_name(),
+		));
+
+		// show the list?
+		if (!$question_id && $action != 'add')
+		{
+			$this->acp_question_list($module);
+		}
+		else if ($question_id && $action == 'delete')
+		{
+			if ($this->get_service_name() !== $config['captcha_plugin'] || !$this->acp_is_last($question_id))
+			{
+				if (confirm_box(true))
+				{
+					$this->acp_delete_question($question_id);
+
+					trigger_error($user->lang['QUESTION_DELETED'] . adm_back_link($list_url));
+				}
+				else
+				{
+					confirm_box(false, $user->lang['CONFIRM_OPERATION'], build_hidden_fields(array(
+						'question_id'		=> $question_id,
+						'action'			=> $action,
+						'configure'			=> 1,
+						'select_captcha'	=> $this->get_service_name(),
+						))
+					);
+				}
+			}
+			else
+			{
+				trigger_error($user->lang['QA_LAST_QUESTION'] . adm_back_link($list_url), E_USER_WARNING);
+			}
+		}
+		else
+		{
+			// okay, show the editor
+			$error = false;
+			$input_question = request_var('question_text', '', true);
+			$input_answers = request_var('answers', '', true);
+			$input_lang = request_var('lang_iso', '', true);
+			$input_strict = request_var('strict', false);
+			$langs = $this->get_languages();
+
+			foreach ($langs as $lang => $entry)
+			{
+				$template->assign_block_vars('langs', array(
+					'ISO' => $lang,
+					'NAME' => $entry['name'],
+				));
+			}
+
+			$template->assign_vars(array(
+				'U_LIST' => $list_url,
+			));
+
+			if ($question_id)
+			{
+				if ($question = $this->acp_get_question_data($question_id))
+				{
+					$answers = (isset($input_answers[$lang])) ? $input_answers[$lang] : implode("\n", $question['answers']);
+
+					$template->assign_vars(array(
+						'QUESTION_TEXT'		=> ($input_question) ? $input_question : $question['question_text'],
+						'LANG_ISO'			=> ($input_lang) ? $input_lang : $question['lang_iso'],
+						'STRICT'			=> (isset($_REQUEST['strict'])) ? $input_strict : $question['strict'],
+						'ANSWERS'			=> $answers,
+					));
+				}
+				else
+				{
+					trigger_error($user->lang['FORM_INVALID'] . adm_back_link($list_url));
+				}
+			}
+			else
+			{
+				$template->assign_vars(array(
+					'QUESTION_TEXT'		=> $input_question,
+					'LANG_ISO'			=> $input_lang,
+					'STRICT'			=> $input_strict,
+					'ANSWERS'			=> $input_answers,
+				));
+			}
+
+			if ($submit && check_form_key($form_key))
+			{
+				$data = $this->acp_get_question_input();
+
+				if (!$this->validate_input($data))
+				{
+					$template->assign_vars(array(
+						'S_ERROR'			=> true,
+					));
+				}
+				else
+				{
+					if ($question_id)
+					{
+						$this->acp_update_question($data, $question_id);
+					}
+					else
+					{
+						$this->acp_add_question($data);
+					}
+
+					add_log('admin', 'LOG_CONFIG_VISUAL');
+					trigger_error($user->lang['CONFIG_UPDATED'] . adm_back_link($list_url));
+				}
+			}
+			else if ($submit)
+			{
+				trigger_error($user->lang['FORM_INVALID'] . adm_back_link($list_url), E_USER_WARNING);
+			}
+		}
+	}
+
+	/**
+	*  This handles the list overview
+	*/
+	function acp_question_list(&$module)
+	{
+		global $db, $template;
+
+		$sql = 'SELECT *
+			FROM ' . $this->table_captcha_questions;
+		$result = $db->sql_query($sql);
+
+		$template->assign_vars(array(
+			'S_LIST'			=> true,
+		));
+
+		while ($row = $db->sql_fetchrow($result))
+		{
+			$url = $module->u_action . "&amp;question_id={$row['question_id']}&amp;configure=1&amp;select_captcha=" . $this->get_service_name() . '&amp;';
+
+			$template->assign_block_vars('questions', array(
+				'QUESTION_TEXT'		=> $row['question_text'],
+				'QUESTION_ID'		=> $row['question_id'],
+				'QUESTION_LANG'		=> $row['lang_iso'],
+				'U_DELETE'			=> "{$url}action=delete",
+				'U_EDIT'			=> "{$url}action=edit",
+			));
+		}
+		$db->sql_freeresult($result);
+	}
+
+	/**
+	*  Grab a question and bring it into a format the editor understands
+	*/
+	function acp_get_question_data($question_id)
+	{
+		global $db;
+
+		if ($question_id)
+		{
+			$sql = 'SELECT *
+				FROM ' . $this->table_captcha_questions . '
+				WHERE question_id = ' . $question_id;
+			$result = $db->sql_query($sql);
+			$question = $db->sql_fetchrow($result);
+			$db->sql_freeresult($result);
+
+			if (!$question)
+			{
+				return false;
+			}
+
+			$question['answers'] = array();
+
+			$sql = 'SELECT *
+				FROM ' . $this->table_captcha_answers . '
+				WHERE question_id = ' . $question_id;
+			$result = $db->sql_query($sql);
+
+			while ($row = $db->sql_fetchrow($result))
+			{
+				$question['answers'][] = $row['answer_text'];
+			}
+			$db->sql_freeresult($result);
+
+			return $question;
+		}
+	}
+
+	/**
+	*  Grab a question from input and bring it into a format the editor understands
+	*/
+	function acp_get_question_input()
+	{
+		$answers = utf8_normalize_nfc(request_var('answers', '', true));
+		$question = array(
+			'question_text'	=> request_var('question_text', '', true),
+			'strict'		=> request_var('strict', false),
+			'lang_iso'		=> request_var('lang_iso', ''),
+			'answers'		=> (strlen($answers)) ? explode("\n", $answers) : '',
+		);
+
+		return $question;
+	}
+
+	/**
+	*  Update a question.
+	* param mixed $data : an array as created from acp_get_question_input or acp_get_question_data
+	*/
+	function acp_update_question($data, $question_id)
+	{
+		global $db, $cache;
+
+		// easier to delete all answers than to figure out which to update
+		$sql = 'DELETE FROM ' . $this->table_captcha_answers . " WHERE question_id = $question_id";
+		$db->sql_query($sql);
+
+		$langs = $this->get_languages();
+		$question_ary = $data;
+		$question_ary['lang_id'] = $langs[$question_ary['lang_iso']]['id'];
+		unset($question_ary['answers']);
+
+		$sql = 'UPDATE ' . $this->table_captcha_questions . '
+			SET ' . $db->sql_build_array('UPDATE', $question_ary) . "
+			WHERE question_id = $question_id";
+		$db->sql_query($sql);
+
+		$this->acp_insert_answers($data, $question_id);
+
+		$cache->destroy('sql', $this->table_captcha_questions);
+	}
+
+	/**
+	*  Insert a question.
+	* param mixed $data : an array as created from acp_get_question_input or acp_get_question_data
+	*/
+	function acp_add_question($data)
+	{
+		global $db, $cache;
+
+		$langs = $this->get_languages();
+		$question_ary = $data;
+
+		$question_ary['lang_id'] = $langs[$data['lang_iso']]['id'];
+		unset($question_ary['answers']);
+
+		$sql = 'INSERT INTO ' . $this->table_captcha_questions . ' ' . $db->sql_build_array('INSERT', $question_ary);
+		$db->sql_query($sql);
+
+		$question_id = $db->sql_nextid();
+
+		$this->acp_insert_answers($data, $question_id);
+
+		$cache->destroy('sql', $this->table_captcha_questions);
+	}
+
+	/**
+	*  Insert the answers.
+	* param mixed $data : an array as created from acp_get_question_input or acp_get_question_data
+	*/
+	function acp_insert_answers($data, $question_id)
+	{
+		global $db, $cache;
+
+		foreach ($data['answers'] as $answer)
+		{
+			$answer_ary = array(
+				'question_id'	=> $question_id,
+				'answer_text'	=> $answer,
+			);
+
+			$sql = 'INSERT INTO ' . $this->table_captcha_answers . ' ' . $db->sql_build_array('INSERT', $answer_ary);
+			$db->sql_query($sql);
+		}
+
+		$cache->destroy('sql', $this->table_captcha_answers);
+	}
+
+	/**
+	*  Delete a question.
+	*/
+	function acp_delete_question($question_id)
+	{
+		global $db, $cache;
+
+		$tables = array($this->table_captcha_questions, $this->table_captcha_answers);
+
+		foreach ($tables as $table)
+		{
+			$sql = "DELETE FROM $table
+				WHERE question_id = $question_id";
+			$db->sql_query($sql);
+		}
+
+		$cache->destroy('sql', $tables);
+	}
+
+	/**
+	*  Check if the entered data can be inserted/used
+	* param mixed $data : an array as created from acp_get_question_input or acp_get_question_data
+	*/
+	function validate_input($question_data)
+	{
+		$langs = $this->get_languages();
+
+		if (!isset($question_data['lang_iso']) ||
+			!isset($question_data['question_text']) ||
+			!isset($question_data['strict']) ||
+			!isset($question_data['answers']))
+		{
+			return false;
+		}
+
+		if (!isset($langs[$question_data['lang_iso']]) ||
+			!strlen($question_data['question_text']) ||
+			!sizeof($question_data['answers']) ||
+			!is_array($question_data['answers']))
+		{
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	* List the installed language packs
+	*/
+	function get_languages()
+	{
+		global $db;
+
+		$sql = 'SELECT *
+			FROM ' . LANG_TABLE;
+		$result = $db->sql_query($sql);
+
+		$langs = array();
+		while ($row = $db->sql_fetchrow($result))
+		{
+			$langs[$row['lang_iso']] = array(
+				'name'	=> $row['lang_local_name'],
+				'id'	=> (int) $row['lang_id'],
+			);
+		}
+		$db->sql_freeresult($result);
+
+		return $langs;
+	}
+
+
+
+	/**
+	*  See if there is a question other than the one we have
+	*/
+	function acp_is_last($question_id)
+	{
+		global $config, $db;
+
+		if ($question_id)
+		{
+			$sql = 'SELECT question_id
+				FROM ' . $this->table_captcha_questions . "
+				WHERE lang_iso = '" . $db->sql_escape($config['default_lang']) . "'
+					AND  question_id <> " .  (int) $question_id;
+			$result = $db->sql_query_limit($sql, 1);
+			$question = $db->sql_fetchrow($result);
+			$db->sql_freeresult($result);
+
+			if (!$question)
+			{
+				return true;
+			}
+			return false;
+		}
+	}
+}