php - PHP：非法的字符串偏移量

Question

我的开源项目工作得很好，直到我在休息 6 个月后开始工作。更新到最新的 XAMPP，开始出现大量奇怪的错误，其中之一是：

我有 Input 类，调用者方法为：

<?php
class Input
{
    public function __call ( $name , $arguments )
    {
        if ( !in_array( $name, array( "post", "get", "cookie", "request", "server", "env" ) ) )
        {
            throw new Exception( "Input::" . $name . "() not declared!" );
        }

        $_name_of_superglobal = "_" . strtoupper( $name );
        $_max_iteration_level_for_cleanup = in_array( $name, array( "server", "env" ) ) ? 1 : 10;

        # $arguments[0] is the index of the value, to be fetched from within the array.
        if ( !empty( $arguments[0] ) and array_key_exists( $arguments[0], $this->$name ) )
        {
            return $this->$name[ $arguments[0] ];
        }
        elseif ( !empty( $arguments[0] ) and array_key_exists( $arguments[0], $GLOBALS[ $_name_of_superglobal ] ) )
        {
            return $this->$name[ $this->clean__makesafe_key( $arguments[0] ) ] = $this->clean__makesafe_value( $GLOBALS[ $_name_of_superglobal ][ $arguments[0] ], array(), true );
        }
        elseif ( !empty( $arguments[0] ) and !array_key_exists( $arguments[0], $GLOBALS[ $_name_of_superglobal ] ) )
        {
            return null;
        }
        else
        {
            if ( $this->_is_cleanup_done_for[ $name ] === true )
            {
                return $this->$name;
            }
            $this->_is_cleanup_done_for[ $name ] = true;
            return $this->$name = $this->clean__makesafe_recursively( $GLOBALS[ $_name_of_superglobal ], $_max_iteration_level_for_cleanup );
        }
    }
?>

这段代码的工作原理是这样的：你向它询问某些超全局值，它会按需返回它的干净版本：

<?php
$input = new Input();
$server_name = $input->server("SERVER_NAME");
?>

容易吧？好吧，在我用 XAMPP 更新 PHP 之后，它就不起作用了[编辑：它起作用了，带有警告消息] - 错误是：

PHP Warning:  Illegal string offset 'SERVER_NAME' in S:\...\kernel\input.php on line 159

行，对应于代码行：

return $this->$name[ $this->clean__makesafe_key( $arguments[0] ) ] = $this->clean__makesafe_value( $GLOBALS[ $_name_of_superglobal ][ $arguments[0] ], array(), true );

这是愚蠢的：$_name_of_superglobal= "_SERVER" 那里，和$arguments[0]= "SERVER_NAME" 和整体分配是被清理的字符串。

那里可能有什么问题？我完全迷失在这里！

Answer 1

介绍

我知道这已经得到解答，但这Illegal string offset ERROR不是我在这里看到的唯一问题。我相信它们是引入您想要的灵活性的更好方法，并且仍然可以在没有所有这些complexity和使用$GLOBALS.

您可以从查看以下内容开始：

• PHP中的全局变量被认为是不好的做法吗？如果是这样，为什么？
• PHP 全局函数
• 为什么全局状态是魔鬼，以及如何避免使用它

快速复审

$input = new Input();                          <-- You add to initiate a class 
$server_name = $input->server("SERVER_NAME");
      ^                  ^           ^
      |                  |           |
    variable             |           |
                     Variable        |
                                  Variable 

不知道是什么阻止你只是使用

    $_SERVER['SERVER_NAME'] = makeSave($_SERVER['SERVER_NAME']);
                                  ^
                                  |- I guess this is what you want to introduce 

假设 - 你想要灵活性

以免假设您想要灵活性和递归，那么您的类调用可以像以下那样灵活：

print_r($input->SERVER_NAME);            |
print_r($input['SERVER_NAME']);          |----- Would Produce same result 
print_r($input->SERVER_NAME());          |

如果这是您想要的那种灵活性，我会考虑将您结合起来__get，__call并且ArrayAccess完全...

让我们想象一下

$var = array();
$var["name"] = "<b>" . $_SERVER['SERVER_NAME'] . "</b>";
$var["example"]['xss'] = '<IMG SRC=javascript:alert("XSS")>';
$var["example"]['sql'] = "x' AND email IS NULL; --";
$var["example"]['filter'] = "Let's meet  4:30am Ât the \tcafé\n";

$_SERVER['SERVER_NAME'] = $var ; // Just for example 

现在回到你的格式

$makeSave = new MakeSafe(MakeSafe::SAVE_XSS | MakeSafe::SAVE_FILTER);
$input = new Input($_SERVER, $makeSafe);

//You can 
print_r($input->SERVER_NAME);

//Or
print_r($input['SERVER_NAME']);

//Or
print_r($input->SERVER_NAME());

他们都会输出

Array
(
    [0] => <b>localhost</b>
    [1] => Array
        (
            [0] => <IMG SRC=javascript:alert("XSS")>
            [1] => x' AND email IS NULL; --
            [2] => Let's meet  4:30am Ât the 	café

        )

)

观看现场演示

您的 INPUT 类已修改

class INPUT implements \ArrayAccess {
    private $request = array();
    private $makeSafe;

    public function __construct(array $array, MakeSafe $makeSafe) {
        $this->request = $array;
        $this->makeSave = $makeSafe;
    }

    function __get($offset) {
        return $this->offsetGet($offset);
    }

    function __call($offset, $value) {
        return $this->offsetGet($offset);
    }

    public function setRequest(array $array) {
        $this->request = $array;
    }

    public function offsetSet($offset, $value) {
        trigger_error("Error: SUPER GLOBAL data cannot be modified");
    }

    public function offsetExists($offset) {
        return isset($this->request[$offset]);
    }

    public function offsetUnset($offset) {
        unset($this->request[$offset]);
    }

    public function offsetGet($offset) {
        return isset($this->request[$offset]) ? $this->makeSave->parse($this->request[$offset]) : null;
    }
}

让你的 Save 方法成为一个类

class MakeSafe {
    const SAVE_XSS = 1;
    const SAVE_SQL = 2;
    const SAVE_FILTER_HIGH = 4;
    const SAVE_FILTER_LOW = 8;
    const SAVE_FILTER = 16;

    private $options;

    function __construct($options) {
        $this->options = $options;
    }

    function escape($value) {
        if ($value = @mysql_real_escape_string($value))
            return $value;
        $return = '';
        for($i = 0; $i < strlen($value); ++ $i) {
            $char = $value[$i];
            $ord = ord($char);
            if ($char !== "'" && $char !== "\"" && $char !== '\\' && $ord >= 32 && $ord <= 126)
                $return .= $char;
            else
                $return .= '\\x' . dechex($ord);
        }
        return $return;
    }

    function parse($mixed) {
        if (is_string($mixed)) {
            $this->options & self::SAVE_XSS and $mixed = htmlspecialchars($mixed, ENT_QUOTES, 'UTF-8');
            $this->options & self::SAVE_SQL and $mixed = $this->escape($mixed);
            $this->options & self::SAVE_FILTER_HIGH and $mixed = filter_var($mixed, FILTER_SANITIZE_STRING, FILTER_FLAG_ENCODE_HIGH);
            $this->options & self::SAVE_FILTER_LOW and $mixed = filter_var($mixed, FILTER_SANITIZE_STRING, FILTER_FLAG_ENCODE_LOW);
            $this->options & self::SAVE_FILTER and $mixed = filter_var($mixed, FILTER_SANITIZE_STRING, FILTER_FLAG_ENCODE_HIGH | FILTER_FLAG_ENCODE_LOW);
            return $mixed;
        }

        if (is_array($mixed)) {
            $all = array();
            foreach ( $mixed as $data ) {
                $all[] = $this->parse($data);
            }
            return $all;
        }
        return $mixed;

        return $this->final;
    }
}

结论

我是否说过我知道这已得到解答，但我希望这可以帮助其他人不要编写像您这样的代码...

PS：这也修复了您的 PHP 警告：非法字符串偏移错误

Answer 2

我在这里找到了答案。显然，这条线

return $this->$name[ $this->clean__makesafe_key( $arguments[0] ) ] = $this->clean__makesafe_value( $GLOBALS[ $_name_of_superglobal ][ $arguments[0] ], array(), true );

应该是这样的：

return $this->{$name}[ $this->clean__makesafe_key( $arguments[0] ) ] = $this->clean__makesafe_value( $GLOBALS[ $_name_of_superglobal ][ $arguments[0] ], array(), true );

由于优先。