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PHP data filtering function and method examples, PHP filtering function examples_PHP tutorial
- WBOYOriginal
- 2016-07-13 10:14:47794browse
Examples of php data filtering functions and methods, examples of php filtering functions
1. Basic principles of php submitted data filtering1) When submitting variables into the database, we must use addslashes() performs filtering. For example, our injection problem can be solved with just addslashes(). In fact, when it comes to variable values, the intval() function is also a good choice for filtering strings.
2) Enable magic_quotes_gpc and magic_quotes_runtime in php.ini. magic_quotes_gpc can change the quotation marks in get, post, and cookie into slashes. magic_quotes_runtime can play a formatting role in data entering and exiting the database. In fact, this parameter was very popular back in the old days when injection was crazy.
3) When using system functions, you must use escapeshellarg() and escapeshellcmd() parameters to filter, so that you can use system functions with confidence.
4) For cross-site, the two parameters of strip_tags() and htmlspecialchars() are both good. All tags with html and php submitted by users will be converted. For example, angle brackets "33b5144e4be82eb7df98d343b451f03d
名字转换
之前每个例子都使用了数组$clean。对于开发人员判断数据是否有潜在的威胁这是一个很好的习惯。 永远不要在对数据验证后还将其保存在$_POST或者$_GET中，作为开发人员对超级全局数组中保存的数据总是应当保持充分的怀疑。
需要补充的是，使用$clean可以帮助思考还有什么没有被过滤，这更类似一个白名单的作用。可以提升安全的等级。
如果仅仅将验证过的数据保存在$clean，在数据验证上仅存的风险是你所引用的数组元素不存在，而不是未过滤的危险数据。
时机
一旦 PHP 脚本开始执行，则意味着 HTTP 请求已经全部结束。此时，用户便没有机会向脚本发送数据。因此，没有数据可以被输入到脚本中(甚至register_globals被开启的情况下)。这就是为什么初始化变量是非常好的习惯。
防注入
代码如下 复制代码
//PHP整站防注入程序，需要在公共文件中require_once本文件
//判断magic_quotes_gpc状态
if (@get_magic_quotes_gpc ()) {
$_GET = sec ( $_GET );
$_POST = sec ( $_POST );
$_COOKIE = sec ( $_COOKIE );
$_FILES = sec ( $_FILES );
}
$_SERVER = sec ( $_SERVER );
function sec(&$array) {
//如果是数组，遍历数组，递归调用
if (is_array ( $array )) {
foreach ( $array as $k => $v ) {
$array [$k] = sec ( $v );
}
} else if (is_string ( $array )) {
//使用addslashes函数来处理
$array = addslashes ( $array );
} else if (is_numeric ( $array )) {
$array = intval ( $array );
}
return $array;
}
//整型过滤函数
function num_check($id) {
if (! $id) {
die ( '参数不能为空!' );
} //是否为空的判断
else if (inject_check ( $id )) {
die ( '非法参数' );
} //注入判断
else if (! is_numetic ( $id )) {
die ( '非法参数' );
}
//数字判断
$id = intval ( $id );
//整型化
return $id;
}
//字符过滤函数
function str_check($str) {
if (inject_check ( $str )) {
die ( '非法参数' );
}
//注入判断
$str = htmlspecialchars ( $str );
//转换html
return $str;
}
function search_check($str) {
$str = str_replace ( "_", "_", $str );
//把"_"过滤掉
$str = str_replace ( "%", "%", $str );
//把"%"过滤掉
$str = htmlspecialchars ( $str );
//转换html
return $str;
}
//表单过滤函数
function post_check($str, $min, $max) {
if (isset ( $min ) && strlen ( $str ) < $min) {
die ( '最少$min字节' );
} else if (isset ( $max ) && strlen ( $str ) > $max) {
die ( '最多$max字节' );
}
return stripslashes_array ( $str );
}
//防注入函数
function inject_check($sql_str) {
return eregi ( 'select|inert|update|delete|'|/*|*|../|./|UNION|into|load_file|outfile', $sql_str );
//进行过滤，防注入
}
function stripslashes_array(&$array) {
if (is_array ( $array )) {
foreach ( $array as $k => $v ) {
$array [$k] = stripslashes_array ( $v );
}
} else if (is_string ( $array )) {
$array = stripslashes ( $array );
}
return $array;
}
?>
addslashes
htmlspecialchars
mysql_real_escape_string
数字的可以用intval()，最好在之前就循环$_POST，挨个的addslashes或者其他函数。
上面都可以，根据需要来。
假定你的数据在数据$demo中，我们来写段代码进行过滤。
$count = 0;
foreach($demo as $ditem){
if(($ditem['a']==0)||($ditem['b']==0)||($ditem['c']==0)||($ditem['c']==0)) continue;
echo $ditem['id'].' '.$ditem['a'].' '.$ditem['b'].' '.$ditem['c'].' '.$ditem['d'].' '.$ditem['e']."0c6dc11e160d3b678d68754cc175188a";
$count++;
}
echo '总行数:'.$count;
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