<?php

if ( getConfig('yubikey_enable', '1') != '1' )

		return true;

// hook into auth

$plugins->attachHook('login_process_userdata_json', 'return yubikey_auth_hook_json($userinfo, $req["level"], @$req["remember"]);');

// hook into special page init

$plugins->attachHook('session_started', 'yubikey_add_special_pages();');

// session key security

$plugins->attachHook('session_key_calc', 'yubikey_sk_calc($user_id, $key_pieces, $sk_mode);');

function yubikey_auth_hook_json(&$userdata, $level, $remember)

{

	global $db, $session, $paths, $template, $plugins; // Common objects

	global $lang;

	$do_validate_otp = false;

	$do_validate_user = false;

	$do_validate_pass = false;

	$user_flag = ( $level >= USER_LEVEL_CHPREF ) ? YK_SEC_ELEV_USERNAME : YK_SEC_NORMAL_USERNAME;

	$pass_flag = ( $level >= USER_LEVEL_CHPREF ) ? YK_SEC_ELEV_PASSWORD : YK_SEC_NORMAL_PASSWORD;

	$auth_log_prefix = ( $level >= USER_LEVEL_CHPREF ) ? 'admin_' : '';

	// Sort of a hack: if the password looks like an OTP and the OTP field is empty, use the password as the OTP

	if ( empty($userdata['yubikey_otp']) && preg_match('/^[cbdefghijklnrtuv]{44}$/', $userdata['password'] ) )

	{

		$userdata['yubikey_otp'] = $userdata['password'];

	}

	// Lockouts removed from here - they're done during preprocessing now.

	if ( !empty($userdata['username']) )

	{

		// get flags

		$q = $db->sql_query('SELECT user_id, user_yubikey_flags FROM ' . table_prefix . "users WHERE " . ENANO_SQLFUNC_LOWERCASE . "(username) = '" . $db->escape(strtolower($userdata['username'])) . "';");

		if ( !$q )

			$db->die_json();

		if ( $db->numrows() < 1 )

		{

			// Username not found - let the main login function handle it

			$db->free_result();

			return null;

		}

		list($user_id, $flags) = $db->fetchrow_num();

		$flags = intval($flags);

		// At the point the username is validated.

		$do_validate_user = false;

		$do_validate_pass = $flags & $pass_flag;

		if ( empty($userdata['yubikey_otp']) )

		{

			// no OTP was provided

			// make sure the user has allowed logging in with no OTP

			if ( !($flags & YK_SEC_ALLOW_NO_OTP) )

			{

				// We also might have no Yubikeys enrolled.

				$q = $db->sql_query('SELECT 1 FROM ' . table_prefix . "yubikey WHERE user_id = $user_id;");

				if ( !$q )

					$db->die_json();

				if ( $db->numrows() > 0 )

				{

					// Yep at least one key is enrolled.

					// I don't think these should be logged because they'll usually just be innocent mistakes.

					$db->free_result();

					return array(

							'mode' => 'error',

							'error' => 'yubiauth_err_must_have_otp'

						);

				}

				// Nope, no keys enrolled, user hasn't enabled Yubikey support

				$db->free_result();

			}

			// we're ok, use normal password auth

			return null;

		}

		else

		{

			// user did enter an OTP; make sure it's associated with the username

			$yubi_uid = $db->escape(substr($userdata['yubikey_otp'], 0, 12));

			$q = $db->sql_query('SELECT user_id FROM ' . table_prefix . 'yubikey WHERE yubi_uid = \'' . $yubi_uid . '\';');

			if ( !$q )

				$db->die_json();

			if ( $db->numrows() < 1 )

			{

				$db->free_result();

				return array(

						'mode' => 'error',

						'error' => 'yubiauth_err_key_not_authorized'

					);

			}

			list($yubi_pair_uid) = $db->fetchrow_num();

			if ( $yubi_pair_uid !== $user_id )

			{

				return array(

						'mode' => 'error',

						'error' => 'yubiauth_err_uid_mismatch'

					);

			}

			$db->free_result();

			$do_validate_otp = true;

		}

	}

	else if ( !empty($userdata['yubikey_otp']) )

	{

		// we have an OTP, but no username to work with

		$yubi_uid = substr($userdata['yubikey_otp'], 0, 12);

		if ( !preg_match('/^[cbdefghijklnrtuv]{12}$/', $yubi_uid ) )

		{

			return array(

					'mode' => 'error',

					'error' => 'yubiauth_err_invalid_otp'

				);

		}

		$q = $db->sql_query('SELECT u.user_id, u.username, u.user_yubikey_flags FROM ' . table_prefix . "users AS u\n"

											. "  LEFT JOIN " . table_prefix . "yubikey AS y\n"

											. "    ON ( y.user_id = u.user_id )\n"

											. "  WHERE y.yubi_uid = '$yubi_uid'\n"

											. "  GROUP BY u.user_yubikey_flags;");

		if ( !$q )

			$db->_die();

		if ( $db->numrows() < 1 )

		{

			if ( !$do_validate_pass )

				$session->sql('INSERT INTO ' . table_prefix . "logs(log_type,action,time_id,date_string,author,edit_summary,page_text) VALUES\n"

 									. '  (\'security\', \'' . $auth_log_prefix . 'auth_bad\', '.time().', \'DEPRECATED\', \'(Yubikey)\', '

											. '\''.$db->escape($_SERVER['REMOTE_ADDR']).'\', ' . intval($level) . ')');

			return array(

					'mode' => 'error',

					'error' => 'yubiauth_err_key_not_authorized'

				);

		}

		list($user_id, $username, $flags) = $db->fetchrow_num();

		if ( $level > USER_LEVEL_MEMBER )

		{

			$session->start();

			if ( $session->user_logged_in && ($session->user_id !== $user_id) )

			{

				return array(

						'mode' => 'error',

						'error' => 'yubiauth_err_uid_mismatch'

					);

			}

		}

		$do_validate_otp = true;

		$do_validate_user = $flags & $user_flag;

		$do_validate_pass = $flags & $pass_flag;

		// to complete security logs later

		$userdata['username'] = $username;

	}

	else

	{

		// Nothing - no username or OTP. This request can't be used; throw it out.

		return array(

				'mode' => 'error',

				'error' => 'yubiauth_err_nothing_provided'

			);

	}

	if ( $do_validate_otp )

	{

		// We need to validate the OTP.

		$otp_check = yubikey_validate_otp($userdata['yubikey_otp']);

		if ( !$otp_check['success'] )

		{

			if ( !$do_validate_pass )

				$session->sql('INSERT INTO ' . table_prefix . "logs(log_type,action,time_id,date_string,author,edit_summary,page_text) VALUES\n"

 									. '  (\'security\', \'' . $auth_log_prefix . 'auth_bad\', '.time().', \'DEPRECATED\', \'(Yubikey)\', '

											. '\''.$db->escape($_SERVER['REMOTE_ADDR']).'\', ' . intval($level) . ')');

			if ( $otp_check['error'] === 'http_failed' )

			{

				return array(

						'mode' => 'error',

						'error' => 'yubiauth_err_' . $otp_check['error'],

						'http_error' => $otp_check['http_error']

					);

			}

			return array(

					'mode' => 'error',

					'error' => 'yubiauth_err_' . $otp_check['error']

				);

		}

	}

	if ( $do_validate_user )

	{

		if ( empty($username) )

		{

			return array(

					'mode' => 'error',

					'error' => 'yubiauth_err_must_have_username'

				);

		}

		if ( strtolower($username) !== strtolower($userdata['username']) )

		{

			// Username incorrect

			if ( !$do_validate_pass )

				$session->sql('INSERT INTO ' . table_prefix . "logs(log_type,action,time_id,date_string,author,edit_summary,page_text) VALUES\n"

 									. '  (\'security\', \'' . $auth_log_prefix . 'auth_bad\', '.time().', \'DEPRECATED\', \'(Yubikey)\', '

											. '\''.$db->escape($_SERVER['REMOTE_ADDR']).'\', ' . intval($level) . ')');

			return array(

					'mode' => 'error',

					'error' => 'invalid_credentials'

				);

		}

	}

	// Do we need to have the password validated?

	if ( $do_validate_pass )

	{

		if ( empty($userdata['password']) )

		{

			return array(

					'mode' => 'error',

					'error' => 'yubiauth_err_must_have_password'

				);

		}

		// Yes; return and let the login API continue

		return null;

	}

	else

	{

		// No password required; validated, issue session key

		$session->sql('INSERT INTO ' . table_prefix . "logs(log_type,action,time_id,date_string,author,edit_summary,page_text) VALUES\n"

 									. '  (\'security\', \'' . $auth_log_prefix . 'auth_good\', '.time().', \'DEPRECATED\', \'' . $db->escape($userdata['username']) . '\', '

											. '\''.$db->escape($_SERVER['REMOTE_ADDR']).'\', ' . intval($level) . ')');

		$q = $db->sql_query('SELECT password FROM ' . table_prefix . "users WHERE user_id = $user_id;");

		if ( !$q )

			$db->_die();

		list($password) = $db->fetchrow_num();

		$db->free_result();

		$session->register_session($user_id, $userdata['username'], $password, intval($level), $remember);

		return true;

	}

}

function yubikey_add_special_pages()

{

	global $db, $session, $paths, $template, $plugins; // Common objects

	global $lang;

	if ( getConfig('yubikey_enable', '1') != '1' )

		return true;

	$paths->add_page(array(

			'name' => $lang->get('yubiauth_specialpage_yubikey'),

			'urlname' => 'Yubikey',

			'namespace' => 'Special',

			'visible' => 0, 'protected' => 0, 'comments_on' => 0, 'special' => 0

		));

}

function yubikey_sk_calc($user_id, &$key_pieces, &$sk_mode)

{

	global $db, $session, $paths, $template, $plugins; // Common objects

	// hash the user's yubikeys

	$q = $db->sql_query('SELECT yubi_uid FROM ' . table_prefix . "yubikey WHERE user_id = $user_id;");

	if ( !$q )

		$db->_die();

	while ( $row = $db->fetchrow() )

	{

		$key_pieces[] = $row['yubi_uid'];

	}

}

function page_Special_Yubikey()

{

	global $db, $session, $paths, $template, $plugins; // Common objects

	header('Content-type: text/javascript');

	/*

	if ( isset($_GET['validate_otp']) )

	{

		echo enano_json_encode(yubikey_validate_otp($_GET['validate_otp']));

		return true;

	}

	*/

	if ( isset($_GET['get_flags']) || isset($_POST['get_flags']) )

	{

		$yubi_uid = substr($_REQUEST['get_flags'], 0, 12);

		if ( !preg_match('/^[cbdefghijklnrtuv]{12}$/', $yubi_uid) )

		{

			return print enano_json_encode(array(

					'mode' => 'error',

					'error' => 'invalid_otp'

				));

		}

		$q = $db->sql_query('SELECT u.user_yubikey_flags FROM ' . table_prefix . "users AS u\n"

											. "  LEFT JOIN " . table_prefix . "yubikey AS y\n"

											. "    ON ( y.user_id = u.user_id )\n"

											. "  WHERE y.yubi_uid = '$yubi_uid'\n"

											. "  GROUP BY u.user_yubikey_flags;");

		if ( !$q )

			$db->_die();

		if ( $db->numrows() < 1 )

		{

			return print enano_json_encode(array(

					'mode' => 'error',

					'error' => 'key_not_authorized'

				));

		}

		list($flags) = $db->fetchrow_num();

		echo enano_json_encode(array(

				// We strip YK_SEC_ALLOW_NO_OTP here for security reasons.

				'flags' => intval($flags & ~YK_SEC_ALLOW_NO_OTP)

			));

		return true;

	}

}