CasperSecurity
<?php
/**
* Get user's global privileges and some db-specific privileges
*/
declare(strict_types=1);
namespace PhpMyAdmin;
use PhpMyAdmin\Query\Utilities;
use PhpMyAdmin\Utils\SessionCache;
use function mb_strpos;
use function mb_substr;
use function preg_match;
use function preg_replace;
use function strpos;
/**
* PhpMyAdmin\CheckUserPrivileges class
*/
class CheckUserPrivileges
{
/** @var DatabaseInterface */
private $dbi;
/**
* @param DatabaseInterface $dbi DatabaseInterface object
*/
public function __construct(DatabaseInterface $dbi)
{
$this->dbi = $dbi;
}
/**
* Extracts details from a result row of a SHOW GRANT query
*
* @param string $row grant row
*
* @return array
*/
public function getItemsFromShowGrantsRow(string $row): array
{
$db_name_offset = mb_strpos($row, ' ON ') + 4;
$tblname_end_offset = mb_strpos($row, ' TO ');
$tblname_start_offset = false;
$__tblname_start_offset = mb_strpos($row, '`.', $db_name_offset);
if ($__tblname_start_offset && $__tblname_start_offset < $tblname_end_offset) {
$tblname_start_offset = $__tblname_start_offset + 1;
}
if ($tblname_start_offset === false) {
$tblname_start_offset = mb_strpos($row, '.', $db_name_offset);
}
$show_grants_dbname = mb_substr(
$row,
$db_name_offset,
$tblname_start_offset - $db_name_offset
);
$show_grants_dbname = Util::unQuote($show_grants_dbname, '`');
$show_grants_str = mb_substr(
$row,
6,
mb_strpos($row, ' ON ') - 6
);
$show_grants_tblname = mb_substr(
$row,
$tblname_start_offset + 1,
$tblname_end_offset - $tblname_start_offset - 1
);
$show_grants_tblname = Util::unQuote($show_grants_tblname, '`');
return [
$show_grants_str,
$show_grants_dbname,
$show_grants_tblname,
];
}
/**
* Check if user has required privileges for
* performing 'Adjust privileges' operations
*
* @param string $show_grants_str string containing grants for user
* @param string $show_grants_dbname name of db extracted from grant string
* @param string $show_grants_tblname name of table extracted from grant string
*/
public function checkRequiredPrivilegesForAdjust(
string $show_grants_str,
string $show_grants_dbname,
string $show_grants_tblname
): void {
// '... ALL PRIVILEGES ON *.* ...' OR '... ALL PRIVILEGES ON `mysql`.* ..'
// OR
// SELECT, INSERT, UPDATE, DELETE .... ON *.* OR `mysql`.*
if ($show_grants_str !== 'ALL'
&& $show_grants_str !== 'ALL PRIVILEGES'
&& (mb_strpos(
$show_grants_str,
'SELECT, INSERT, UPDATE, DELETE'
) === false)
) {
return;
}
if ($show_grants_dbname === '*'
&& $show_grants_tblname === '*'
) {
$GLOBALS['col_priv'] = true;
$GLOBALS['db_priv'] = true;
$GLOBALS['proc_priv'] = true;
$GLOBALS['table_priv'] = true;
if ($show_grants_str === 'ALL PRIVILEGES'
|| $show_grants_str === 'ALL'
) {
$GLOBALS['is_reload_priv'] = true;
}
}
// check for specific tables in `mysql` db
// Ex. '... ALL PRIVILEGES on `mysql`.`columns_priv` .. '
if ($show_grants_dbname !== 'mysql') {
return;
}
switch ($show_grants_tblname) {
case 'columns_priv':
$GLOBALS['col_priv'] = true;
break;
case 'db':
$GLOBALS['db_priv'] = true;
break;
case 'procs_priv':
$GLOBALS['proc_priv'] = true;
break;
case 'tables_priv':
$GLOBALS['table_priv'] = true;
break;
case '*':
$GLOBALS['col_priv'] = true;
$GLOBALS['db_priv'] = true;
$GLOBALS['proc_priv'] = true;
$GLOBALS['table_priv'] = true;
break;
default:
}
}
/**
* sets privilege information extracted from SHOW GRANTS result
*
* Detection for some CREATE privilege.
*
* Since MySQL 4.1.2, we can easily detect current user's grants using $userlink
* (no control user needed) and we don't have to try any other method for
* detection
*
* @todo fix to get really all privileges, not only explicitly defined for this user
* from MySQL manual: (https://dev.mysql.com/doc/refman/5.0/en/show-grants.html)
* SHOW GRANTS displays only the privileges granted explicitly to the named
* account. Other privileges might be available to the account, but they are not
* displayed. For example, if an anonymous account exists, the named account
* might be able to use its privileges, but SHOW GRANTS will not display them.
*/
private function analyseShowGrant(): void
{
if (SessionCache::has('is_create_db_priv')) {
$GLOBALS['is_create_db_priv'] = SessionCache::get(
'is_create_db_priv'
);
$GLOBALS['is_reload_priv'] = SessionCache::get(
'is_reload_priv'
);
$GLOBALS['db_to_create'] = SessionCache::get(
'db_to_create'
);
$GLOBALS['dbs_where_create_table_allowed'] = SessionCache::get(
'dbs_where_create_table_allowed'
);
$GLOBALS['dbs_to_test'] = SessionCache::get(
'dbs_to_test'
);
$GLOBALS['db_priv'] = SessionCache::get(
'db_priv'
);
$GLOBALS['col_priv'] = SessionCache::get(
'col_priv'
);
$GLOBALS['table_priv'] = SessionCache::get(
'table_priv'
);
$GLOBALS['proc_priv'] = SessionCache::get(
'proc_priv'
);
return;
}
// defaults
$GLOBALS['is_create_db_priv'] = false;
$GLOBALS['is_reload_priv'] = false;
$GLOBALS['db_to_create'] = '';
$GLOBALS['dbs_where_create_table_allowed'] = [];
$GLOBALS['dbs_to_test'] = Utilities::getSystemSchemas();
$GLOBALS['proc_priv'] = false;
$GLOBALS['db_priv'] = false;
$GLOBALS['col_priv'] = false;
$GLOBALS['table_priv'] = false;
$rs_usr = $this->dbi->tryQuery('SHOW GRANTS');
if (! $rs_usr) {
return;
}
$re0 = '(^|(\\\\\\\\)+|[^\\\\])'; // non-escaped wildcards
$re1 = '(^|[^\\\\])(\\\)+'; // escaped wildcards
while ($row = $this->dbi->fetchRow($rs_usr)) {
[
$show_grants_str,
$show_grants_dbname,
$show_grants_tblname,
] = $this->getItemsFromShowGrantsRow($row[0]);
if ($show_grants_dbname === '*') {
if ($show_grants_str !== 'USAGE') {
$GLOBALS['dbs_to_test'] = false;
}
} elseif ($GLOBALS['dbs_to_test'] !== false) {
$GLOBALS['dbs_to_test'][] = $show_grants_dbname;
}
if (mb_strpos($show_grants_str, 'RELOAD') !== false) {
$GLOBALS['is_reload_priv'] = true;
}
// check for the required privileges for adjust
$this->checkRequiredPrivilegesForAdjust(
$show_grants_str,
$show_grants_dbname,
$show_grants_tblname
);
/**
* @todo if we find CREATE VIEW but not CREATE, do not offer
* the create database dialog box
*/
if ($show_grants_str !== 'ALL'
&& $show_grants_str !== 'ALL PRIVILEGES'
&& $show_grants_str !== 'CREATE'
&& strpos($show_grants_str, 'CREATE,') === false
) {
continue;
}
if ($show_grants_dbname === '*') {
// a global CREATE privilege
$GLOBALS['is_create_db_priv'] = true;
$GLOBALS['is_reload_priv'] = true;
$GLOBALS['db_to_create'] = '';
$GLOBALS['dbs_where_create_table_allowed'][] = '*';
// @todo we should not break here, cause GRANT ALL *.*
// could be revoked by a later rule like GRANT SELECT ON db.*
break;
}
// this array may contain wildcards
$GLOBALS['dbs_where_create_table_allowed'][] = $show_grants_dbname;
$dbname_to_test = Util::backquote($show_grants_dbname);
if ($GLOBALS['is_create_db_priv']) {
// no need for any more tests if we already know this
continue;
}
// does this db exist?
if ((! preg_match('/' . $re0 . '%|_/', $show_grants_dbname)
|| preg_match('/\\\\%|\\\\_/', $show_grants_dbname))
&& ($this->dbi->tryQuery(
'USE ' . preg_replace(
'/' . $re1 . '(%|_)/',
'\\1\\3',
$dbname_to_test
)
)
|| mb_substr((string) $this->dbi->getError(), 1, 4) == 1044)
) {
continue;
}
/**
* Do not handle the underscore wildcard
* (this case must be rare anyway)
*/
$GLOBALS['db_to_create'] = preg_replace(
'/' . $re0 . '%/',
'\\1',
$show_grants_dbname
);
$GLOBALS['db_to_create'] = preg_replace(
'/' . $re1 . '(%|_)/',
'\\1\\3',
$GLOBALS['db_to_create']
);
$GLOBALS['is_create_db_priv'] = true;
/**
* @todo collect $GLOBALS['db_to_create'] into an array,
* to display a drop-down in the "Create database" dialog
*/
// we don't break, we want all possible databases
//break;
}
$this->dbi->freeResult($rs_usr);
// must also cacheUnset() them in
// PhpMyAdmin\Plugins\Auth\AuthenticationCookie
SessionCache::set('is_create_db_priv', $GLOBALS['is_create_db_priv']);
SessionCache::set('is_reload_priv', $GLOBALS['is_reload_priv']);
SessionCache::set('db_to_create', $GLOBALS['db_to_create']);
SessionCache::set(
'dbs_where_create_table_allowed',
$GLOBALS['dbs_where_create_table_allowed']
);
SessionCache::set('dbs_to_test', $GLOBALS['dbs_to_test']);
SessionCache::set('proc_priv', $GLOBALS['proc_priv']);
SessionCache::set('table_priv', $GLOBALS['table_priv']);
SessionCache::set('col_priv', $GLOBALS['col_priv']);
SessionCache::set('db_priv', $GLOBALS['db_priv']);
}
/**
* Get user's global privileges and some db-specific privileges
*/
public function getPrivileges(): void
{
$username = '';
$current = $this->dbi->getCurrentUserAndHost();
if (! empty($current)) {
[$username] = $current;
}
// If MySQL is started with --skip-grant-tables
if ($username === '') {
$GLOBALS['is_create_db_priv'] = true;
$GLOBALS['is_reload_priv'] = true;
$GLOBALS['db_to_create'] = '';
$GLOBALS['dbs_where_create_table_allowed'] = ['*'];
$GLOBALS['dbs_to_test'] = false;
$GLOBALS['db_priv'] = true;
$GLOBALS['col_priv'] = true;
$GLOBALS['table_priv'] = true;
$GLOBALS['proc_priv'] = true;
} else {
$this->analyseShowGrant();
}
}
}