php 字符串安全过滤 全攻略

<?php if (!get_magic_quotes_gpc()) { add_slashes($_GET); add_slashes($_POST); add_slashes($_COOKIE); } function add_slashes($string) { if (is_array($string)) { foreach ($string as $key => $value) { $string[$key] = add_slashes($value); } } else { $string = addslashes($string); } return $string; } //php防注入函数,字符过滤函数 //解码 function htmldecode($str) { if(empty($str)) return; if($str=="") return $str; $str=str_replace("select","select",$str); $str=str_replace("join","join",$str); $str=str_replace("union","union",$str); $str=str_replace("where","where",$str); $str=str_replace("insert","insert",$str); $str=str_replace("delete","delete",$str); $str=str_replace("update","update",$str); $str=str_replace("like","like",$str); $str=str_replace("drop","drop",$str); $str=str_replace("create","create",$str); $str=str_replace("modify","modify",$str); $str=str_replace("rename","rename",$str); $str=str_replace("alter","alter",$str); $str=str_replace("cas","cast",$str); $str=str_replace("&","&",$str); $str=str_replace(">",">",$str); $str=str_replace("<","<",$str); $str=str_replace(" ",chr(32),$str); $str=str_replace(" ",chr(9),$str); // $str=str_replace("    ",chr(9),$str); $str=str_replace("&",chr(34),$str); $str=str_replace("'",chr(39),$str); $str=str_replace("<br />",chr(13),$str); $str=str_replace("''","'",$str); return $str; } //编码 function htmlencode($str) { if(empty($str)) return; if($str=="") return $str; $str=trim($str); $str=str_replace("&","&",$str); $str=str_replace(">",">",$str); $str=str_replace("<","<",$str); $str=str_replace(chr(32)," ",$str); $str=str_replace(chr(9)," ",$str); // $str=str_replace(chr(9),"    ",$str); $str=str_replace(chr(34),"&",$str); $str=str_replace(chr(39),"'",$str); $str=str_replace(chr(13),"<br />",$str); $str=str_replace("'","''",$str); $str=str_replace("select","select",$str); $str=str_replace("join","join",$str); $str=str_replace("union","union",$str); $str=str_replace("where","where",$str); $str=str_replace("insert","insert",$str); $str=str_replace("delete","delete",$str); $str=str_replace("update","update",$str); $str=str_replace("like","like",$str); $str=str_replace("drop","drop",$str); $str=str_replace("create","create",$str); $str=str_replace("modify","modify",$str); $str=str_replace("rename","rename",$str); $str=str_replace("alter","alter",$str); $str=str_replace("cast","cas",$str); return $str; } ?>

 

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