PHP利用str_replace防注入的方法_php技巧

PHP各种过滤字符函数

/**
* 安全过滤函数
*
* @param $string
* @return string
*/
function safe_replace($string) {
$string = str_replace('%20','',$string);
$string = str_replace('%27','',$string);
$string = str_replace('%2527','',$string);
$string = str_replace('*','',$string);
$string = str_replace('"','"',$string);
$string = str_replace("'",'',$string);
$string = str_replace('"','',$string);
$string = str_replace(';','',$string);
$string = str_replace(' $string = str_replace('>','>',$string);
$string = str_replace("{",'',$string);
$string = str_replace('}','',$string);
$string = str_replace('','',$string);
return $string;
}
?>

/**
* 返回经addslashes处理过的字符串或数组
* @param $string 需要处理的字符串或数组
* @return mixed
*/
function new_addslashes($string) {
if(!is_array($string)) return addslashes($string);
foreach($string as $key => $val) $string[$key] = new_addslashes($val);
return $string;
}
?>

//对请求的字符串进行安全处理
/*
$safestep
0 为不处理，
1 为禁止不安全HTML内容(javascript等)，
2 完全禁止HTML内容，并替换部份不安全字符串（如：eval(、union、CONCAT(、--、等）
*/
function StringSafe($str, $safestep=-1){
$safestep = ($safestep > -1) ? $safestep : 1;
if($safestep == 1){
$str = preg_replace("#script:#i", "ｓｃｒｉｐｔ：", $str);
$str = preg_replace("#]*>#isU", '', $str);
$str = preg_replace("#[ ]{1,}#", ' ', $str);
return $str;
}else if($safestep == 2){
$str = addslashes(htmlspecialchars(stripslashes($str)));
$str = preg_replace("#eval#i", 'ｅｖａｌ', $str);
$str = preg_replace("#union#i", 'ｕｎｉｏｎ', $str);
$str = preg_replace("#concat#i", 'ｃｏｎｃａｔ', $str);
$str = preg_replace("#--#", '－－', $str);
$str = preg_replace("#[ ]{1,}#", ' ', $str);
return $str;
}else{
return $str;
}
}
?>

/**
+----------------------------------------------------------
* 输出安全的html，用于过滤危险代码
+----------------------------------------------------------
* @access public
+----------------------------------------------------------
* @param string $text 要处理的字符串
* @param mixed $tags 允许的标签列表，如 table|td|th|td
+----------------------------------------------------------
* @return string
+----------------------------------------------------------
*/
static public function safeHtml($text, $tags = null)
{
$text = trim($text);
//完全过滤注释
$text = preg_replace('//','',$text);
//完全过滤动态代码
$text = preg_replace('/|?'.'>/','',$text);
//完全过滤js
$text = preg_replace('/

function RemoveXSS($val) {
// remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed
// this prevents some character re-spacing such as
// note that you have to handle splits with , , and later since they *are* allowed in some // inputs
$val = preg_replace('/([x00-x08,x0b-x0c,x0e-x19])/', '', $val);
// straight replacements, the user should never need these since they're normal characters
// this prevents like
$search = 'abcdefghijklmnopqrstuvwxyz';
$search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$search .= '1234567890!@#$%^&*()';
$search .= '~`";:?+/={}[]-_|'';
for ($i = 0; $i // ;? matches the ;, which is optional
// 0{0,7} matches any padded zeros, which are optional and go up to 8 chars
// @ @ search for the hex values
$val = preg_replace('/([xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val);//with a ;
// @ @ 0{0,7} matches '0' zero to seven times
$val = preg_replace('/({0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
}
// now the only remaining whitespace attacks are , , and
$ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
$ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');
$ra = array_merge($ra1, $ra2);
$found = true; // keep replacing as long as the previous round replaced something
while ($found == true) {
$val_before = $val;
for ($i = 0; $i $pattern = '/';
for ($j = 0; $j if ($j > 0) {
$pattern .= '(';
$pattern .= '([xX]0{0,8}([9ab]);)';
$pattern .= '|';
$pattern .= '|({0,8}([9|10|13]);)';
$pattern .= ')*';
}
$pattern .= $ra[$i][$j];
}
$pattern .= '/i';
$replacement = substr($ra[$i], 0, 2).''.substr($ra[$i], 2); // add in to nerf the tag
$val = preg_replace($pattern, $replacement, $val); // filter out the hex tags
if ($val_before == $val) {
// no replacements were made, so exit the loop
$found = false;
}
}
}
return $val;
}
?>