CI源码分析-Input.php


CodeIgniter.php 引入的第九个核心文件($IN)。为了安全性,对输入数据进行预处理,提供了一些辅助方法来获取输入数据并处理。

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string strip_tags ( string $str [, string $allowable_tags ] )

该函数尝试返回给定的字符串 str 去除空字符、HTML 和 PHP 标记后的结果。它使用与函数 fgetss() 一样的机制去除标记。

mixed filter_var ( mixed $variable [, int $filter = FILTER_DEFAULT [, mixed $options ]] )

使用特定的过滤器过滤一个变量

Magic Quotes 、mysql_real_escape_string、stripslashes、addslashes

StackOverFlow

数组操作

待学习:array notation

_allow_get_array        = (config_item('allow_get_array') === TRUE);
        $this->_enable_xss        = (config_item('global_xss_filtering') === TRUE);
        $this->_enable_csrf        = (config_item('csrf_protection') === TRUE);
        $this->_standardize_newlines    = (bool) config_item('standardize_newlines');

        $this->security =& load_class('Security', 'core');

        // Do we need the UTF-8 class?
        if (UTF8_ENABLED === TRUE)
        {
            $this->uni =& load_class('Utf8', 'core');
        }

        // Sanitize global arrays 净化
        $this->_sanitize_globals();

        // CSRF Protection check
        if ($this->_enable_csrf === TRUE && ! is_cli())
        {
            $this->security->csrf_verify();
        }

        log_message('info', 'Input Class Initialized');
    }

    // --------------------------------------------------------------------

    /**
     * Fetch from array
     * 核心参数:获取指定数组中的参数
     *
     * Internal method used to retrieve(取得) values from global arrays.
     *
     * @param    array    &$array        $_GET, $_POST, $_COOKIE, $_SERVER, etc.
     * @param    mixed    $index        Index for item to be fetched from $array
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    protected function _fetch_from_array(&$array, $index = NULL, $xss_clean = NULL)
    {
        is_bool($xss_clean) OR $xss_clean = $this->_enable_xss;

        // If $index is NULL, it means that the whole $array is requested
        // 没有指定 index 则返回所有
        isset($index) OR $index = array_keys($array);

        // allow fetching multiple keys at once
        if (is_array($index))
        {
            $output = array();
            foreach ($index as $key)
            {
                $output[$key] = $this->_fetch_from_array($array, $key, $xss_clean);
            }

            return $output;
        }

        if (isset($array[$index]))
        {
            $value = $array[$index];
        }
        elseif (($count = preg_match_all('/(?:^[^\[]+)|\[[^]]*\]/', $index, $matches)) > 1) // Does the index contain array notation
        {
            $value = $array;
            for ($i = 0; $i < $count; $i++)
            {
                $key = trim($matches[0][$i], '[]');
                if ($key === '') // Empty notation will return the value as array
                {
                    break;
                }

                if (isset($value[$key]))
                {
                    $value = $value[$key];
                }
                else
                {
                    return NULL;
                }
            }
        }
        else
        {
            return NULL;
        }

        return ($xss_clean === TRUE)
            ? $this->security->xss_clean($value)
            : $value;
    }

    // --------------------------------------------------------------------

    /**
     * Fetch an item from the GET array
     *
     * @param    mixed    $index        Index for item to be fetched from $_GET
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function get($index = NULL, $xss_clean = NULL)
    {
        return $this->_fetch_from_array($_GET, $index, $xss_clean);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch an item from the POST array
     *
     * @param    mixed    $index        Index for item to be fetched from $_POST
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function post($index = NULL, $xss_clean = NULL)
    {
        return $this->_fetch_from_array($_POST, $index, $xss_clean);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch an item from POST data with fallback to GET
     *
     * @param    string    $index        Index for item to be fetched from $_POST or $_GET
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function post_get($index, $xss_clean = NULL)
    {
        return isset($_POST[$index])
            ? $this->post($index, $xss_clean)
            : $this->get($index, $xss_clean);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch an item from GET data with fallback to POST
     *
     * @param    string    $index        Index for item to be fetched from $_GET or $_POST
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function get_post($index, $xss_clean = NULL)
    {
        return isset($_GET[$index])
            ? $this->get($index, $xss_clean)
            : $this->post($index, $xss_clean);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch an item from the COOKIE array
     *
     * @param    mixed    $index        Index for item to be fetched from $_COOKIE
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function cookie($index = NULL, $xss_clean = NULL)
    {
        return $this->_fetch_from_array($_COOKIE, $index, $xss_clean);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch an item from the SERVER array
     *
     * @param    mixed    $index        Index for item to be fetched from $_SERVER
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function server($index, $xss_clean = NULL)
    {
        return $this->_fetch_from_array($_SERVER, $index, $xss_clean);
    }

    // ------------------------------------------------------------------------

    /**
     * Fetch an item from the php://input stream
     *
     * Useful when you need to access PUT, DELETE or PATCH request data.
     *
     * @param    string    $index        Index for item to be fetched
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    mixed
     */
    public function input_stream($index = NULL, $xss_clean = NULL)
    {
        // Prior to PHP 5.6, the input stream can only be read once,
        // so we'll need to check if we have already done that first.
        if ( ! is_array($this->_input_stream))
        {
            // $this->raw_input_stream will trigger __get().
            parse_str($this->raw_input_stream, $this->_input_stream);
            is_array($this->_input_stream) OR $this->_input_stream = array();
        }

        return $this->_fetch_from_array($this->_input_stream, $index, $xss_clean);
    }

    // ------------------------------------------------------------------------

    /**
     * Set cookie
     *
     * Accepts an arbitrary number of parameters (up to 7) or an associative
     * array in the first parameter containing all the values.
     *
     * @param    string|mixed[]    $name        Cookie name or an array containing parameters
     * @param    string        $value        Cookie value
     * @param    int        $expire        Cookie expiration time in seconds
     * @param    string        $domain        Cookie domain (e.g.: '.yourdomain.com')
     * @param    string        $path        Cookie path (default: '/')
     * @param    string        $prefix        Cookie name prefix
     * @param    bool        $secure        Whether to only transfer cookies via SSL
     * @param    bool        $httponly    Whether to only makes the cookie accessible via HTTP (no javascript)
     * @return    void
     */
    public function set_cookie($name, $value = '', $expire = '', $domain = '', $path = '/', $prefix = '', $secure = FALSE, $httponly = FALSE)
    {
        if (is_array($name))
        {
            // always leave 'name' in last place, as the loop will break otherwise, due to $$item
            foreach (array('value', 'expire', 'domain', 'path', 'prefix', 'secure', 'httponly', 'name') as $item)
            {
                if (isset($name[$item]))
                {
                    $$item = $name[$item];
                }
            }
        }

        if ($prefix === '' && config_item('cookie_prefix') !== '')
        {
            $prefix = config_item('cookie_prefix');
        }

        if ($domain == '' && config_item('cookie_domain') != '')
        {
            $domain = config_item('cookie_domain');
        }

        if ($path === '/' && config_item('cookie_path') !== '/')
        {
            $path = config_item('cookie_path');
        }

        if ($secure === FALSE && config_item('cookie_secure') === TRUE)
        {
            $secure = config_item('cookie_secure');
        }

        if ($httponly === FALSE && config_item('cookie_httponly') !== FALSE)
        {
            $httponly = config_item('cookie_httponly');
        }

        if ( ! is_numeric($expire))
        {
            $expire = time() - 86500;
        }
        else
        {
            $expire = ($expire > 0) ? time() + $expire : 0;
        }

        setcookie($prefix.$name, $value, $expire, $path, $domain, $secure, $httponly);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch the IP Address
     *
     * Determines and validates the visitor's IP address.
     *
     * @return    string    IP address
     */
    public function ip_address()
    {
        if ($this->ip_address !== FALSE)
        {
            return $this->ip_address;
        }

        $proxy_ips = config_item('proxy_ips');
        if ( ! empty($proxy_ips) && ! is_array($proxy_ips))
        {
            $proxy_ips = explode(',', str_replace(' ', '', $proxy_ips));
        }

        $this->ip_address = $this->server('REMOTE_ADDR');

        if ($proxy_ips)
        {
            foreach (array('HTTP_X_FORWARDED_FOR', 'HTTP_CLIENT_IP', 'HTTP_X_CLIENT_IP', 'HTTP_X_CLUSTER_CLIENT_IP') as $header)
            {
                if (($spoof = $this->server($header)) !== NULL)
                {
                    // Some proxies typically list the whole chain of IP
                    // addresses through which the client has reached us.
                    // e.g. client_ip, proxy_ip1, proxy_ip2, etc.
                    sscanf($spoof, '%[^,]', $spoof);

                    if ( ! $this->valid_ip($spoof))
                    {
                        $spoof = NULL;
                    }
                    else
                    {
                        break;
                    }
                }
            }

            if ($spoof)
            {
                for ($i = 0, $c = count($proxy_ips); $i < $c; $i++)
                {
                    // Check if we have an IP address or a subnet
                    if (strpos($proxy_ips[$i], '/') === FALSE)
                    {
                        // An IP address (and not a subnet) is specified.
                        // We can compare right away.
                        if ($proxy_ips[$i] === $this->ip_address)
                        {
                            $this->ip_address = $spoof;
                            break;
                        }

                        continue;
                    }

                    // We have a subnet ... now the heavy lifting begins
                    isset($separator) OR $separator = $this->valid_ip($this->ip_address, 'ipv6') ? ':' : '.';

                    // If the proxy entry doesn't match the IP protocol - skip it
                    if (strpos($proxy_ips[$i], $separator) === FALSE)
                    {
                        continue;
                    }

                    // Convert the REMOTE_ADDR IP address to binary, if needed
                    if ( ! isset($ip, $sprintf))
                    {
                        if ($separator === ':')
                        {
                            // Make sure we're have the "full" IPv6 format
                            $ip = explode(':',
                                str_replace('::',
                                    str_repeat(':', 9 - substr_count($this->ip_address, ':')),
                                    $this->ip_address
                                )
                            );

                            for ($j = 0; $j < 8; $j++)
                            {
                                $ip[$j] = intval($ip[$j], 16);
                            }

                            $sprintf = '%016b%016b%016b%016b%016b%016b%016b%016b';
                        }
                        else
                        {
                            $ip = explode('.', $this->ip_address);
                            $sprintf = '%08b%08b%08b%08b';
                        }

                        $ip = vsprintf($sprintf, $ip);
                    }

                    // Split the netmask length off the network address
                    sscanf($proxy_ips[$i], '%[^/]/%d', $netaddr, $masklen);

                    // Again, an IPv6 address is most likely in a compressed form
                    if ($separator === ':')
                    {
                        $netaddr = explode(':', str_replace('::', str_repeat(':', 9 - substr_count($netaddr, ':')), $netaddr));
                        for ($i = 0; $i < 8; $i++)
                        {
                            $netaddr[$i] = intval($netaddr[$i], 16);
                        }
                    }
                    else
                    {
                        $netaddr = explode('.', $netaddr);
                    }

                    // Convert to binary and finally compare
                    if (strncmp($ip, vsprintf($sprintf, $netaddr), $masklen) === 0)
                    {
                        $this->ip_address = $spoof;
                        break;
                    }
                }
            }
        }

        if ( ! $this->valid_ip($this->ip_address))
        {
            return $this->ip_address = '0.0.0.0';
        }

        return $this->ip_address;
    }

    // --------------------------------------------------------------------

    /**
     * Validate IP Address
     * 校验IP有效性
     *
     * @param    string    $ip    IP address
     * @param    string    $which    IP protocol: 'ipv4' or 'ipv6'
     * @return    bool
     */
    public function valid_ip($ip, $which = '')
    {
        switch (strtolower($which))
        {
            case 'ipv4':
                $which = FILTER_FLAG_IPV4;
                break;
            case 'ipv6':
                $which = FILTER_FLAG_IPV6;
                break;
            default:
                $which = NULL;
                break;
        }

        return (bool) filter_var($ip, FILTER_VALIDATE_IP, $which);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch User Agent string
     * 
     * 获取 UA
     *
     * @return    string|null    User Agent string or NULL if it doesn't exist
     */
    public function user_agent($xss_clean = NULL)
    {
        return $this->_fetch_from_array($_SERVER, 'HTTP_USER_AGENT', $xss_clean);
    }

    // --------------------------------------------------------------------

    /**
     * Sanitize Globals
     * 净化全局变量
     *
     * Internal method serving for the following purposes:
     *
     *    - Unsets $_GET data, if query strings are not enabled
     *    - Cleans POST, COOKIE and SERVER data
     *     - Standardizes newline characters to PHP_EOL (换行符)
     *
     * @return    void
     */
    protected function _sanitize_globals()
    {
        // Is $_GET data allowed? If not we'll set the $_GET to an empty array
        if ($this->_allow_get_array === FALSE)
        {
            $_GET = array();
        }
        elseif (is_array($_GET))
        {
            foreach ($_GET as $key => $val)
            {
                $_GET[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
            }
        }

        // Clean $_POST Data
        if (is_array($_POST))
        {
            foreach ($_POST as $key => $val)
            {
                $_POST[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
            }
        }

        // Clean $_COOKIE Data
        if (is_array($_COOKIE))
        {
            // 去除无用但会触发检测报警的参数
            // Also get rid of specially treated cookies that might be set by a server
            // or silly application, that are of no use to a CI application anyway
            // but that when present will trip our 'Disallowed Key Characters' alarm
            // http://www.ietf.org/rfc/rfc2109.txt
            // note that the key names below are single quoted strings, and are not PHP variables
            unset(
                $_COOKIE['$Version'],
                $_COOKIE['$Path'],
                $_COOKIE['$Domain']
            );

            foreach ($_COOKIE as $key => $val)
            {
                if (($cookie_key = $this->_clean_input_keys($key)) !== FALSE)
                {
                    $_COOKIE[$cookie_key] = $this->_clean_input_data($val);
                }
                else
                {
                    unset($_COOKIE[$key]);
                }
            }
        }

        // Sanitize PHP_SELF
        $_SERVER['PHP_SELF'] = strip_tags($_SERVER['PHP_SELF']);

        log_message('debug', 'Global POST, GET and COOKIE data sanitized');
    }

    // --------------------------------------------------------------------

    /**
     * Clean Input Data
     *
     * Internal method that aids in escaping data and
     * standardizing newline characters to PHP_EOL.
     *
     * @param    string|string[]    $str    Input string(s)
     * @return    string
     */
    protected function _clean_input_data($str)
    {
        if (is_array($str))
        {
            $new_array = array();
            foreach (array_keys($str) as $key)
            {
                $new_array[$this->_clean_input_keys($key)] = $this->_clean_input_data($str[$key]);
            }
            return $new_array;
        }

        /* We strip slashes if magic quotes is on to keep things consistent
         * 
         * 当 magic_quotes 为 on,所有的 ' (单引号)、" (双引号)、\(反斜杠)和 NUL's 被一个反斜杠自动转义。 

           NOTE: In PHP 5.4 get_magic_quotes_gpc() will always return 0 and
                 it will probably not exist in future versions at all.
        */
        if ( ! is_php('5.4') && get_magic_quotes_gpc())
        {
            $str = stripslashes($str);
        }

        // Clean UTF-8 if supported
        if (UTF8_ENABLED === TRUE)
        {
            $str = $this->uni->clean_string($str);
        }

        // Remove control characters
        $str = remove_invisible_characters($str, FALSE);

        // Standardize newlines if needed
        if ($this->_standardize_newlines === TRUE)
        {
            return preg_replace('/(?:\r\n|[\r\n])/', PHP_EOL, $str);
        }

        return $str;
    }

    // --------------------------------------------------------------------

    /**
     * Clean Keys
     *
     * Internal method that helps to prevent malicious users
     * from trying to exploit keys we make sure that keys are
     * only named with alpha-numeric text and a few other items.
     *
     * @param    string    $str    Input string
     * @param    bool    $fatal    Whether to terminate script exection
     *                or to return FALSE if an invalid (出现问题时是否退出)
     *                key is encountered
     * @return    string|bool
     */
    protected function _clean_input_keys($str, $fatal = TRUE)
    {
        if ( ! preg_match('/^[a-z0-9:_\/|-]+$/i', $str))
        {
            if ($fatal === TRUE)
            {
                return FALSE;
            }
            else
            {
                set_status_header(503);
                echo 'Disallowed Key Characters.';
                exit(7); // EXIT_USER_INPUT
            }
        }

        // Clean UTF-8 if supported
        if (UTF8_ENABLED === TRUE)
        {
            return $this->uni->clean_string($str);
        }

        return $str;
    }

    // --------------------------------------------------------------------

    /**
     * Request Headers
     * 返回 HTTP 请求头数组
     *
     * @param    bool    $xss_clean    Whether to apply XSS filtering
     * @return    array
     */
    public function request_headers($xss_clean = FALSE)
    {
        // If header is already defined, return it immediately
        if ( ! empty($this->headers))
        {
            return $this->headers;
        }

        // In Apache, you can simply call apache_request_headers()
        if (function_exists('apache_request_headers'))
        {
            return $this->headers = apache_request_headers();
        }

        $this->headers['Content-Type'] = isset($_SERVER['CONTENT_TYPE']) ? $_SERVER['CONTENT_TYPE'] : @getenv('CONTENT_TYPE');

        foreach ($_SERVER as $key => $val)
        {
            if (sscanf($key, 'HTTP_%s', $header) === 1)
            {
                // take SOME_HEADER and turn it into Some-Header
                $header = str_replace('_', ' ', strtolower($header));
                $header = str_replace(' ', '-', ucwords($header));

                $this->headers[$header] = $this->_fetch_from_array($_SERVER, $key, $xss_clean);
            }
        }

        return $this->headers;
    }

    // --------------------------------------------------------------------

    /**
     * Get Request Header
     *
     * Returns the value of a single member of the headers class member
     *
     * @param    string        $index        Header name
     * @param    bool        $xss_clean    Whether to apply XSS filtering
     * @return    string|null    The requested header on success or NULL on failure
     */
    public function get_request_header($index, $xss_clean = FALSE)
    {
        static $headers;

        if ( ! isset($headers))
        {
            empty($this->headers) && $this->request_headers();
            foreach ($this->headers as $key => $value)
            {
                $headers[strtolower($key)] = $value;
            }
        }

        $index = strtolower($index);

        if ( ! isset($headers[$index]))
        {
            return NULL;
        }

        return ($xss_clean === TRUE)
            ? $this->security->xss_clean($headers[$index])
            : $headers[$index];
    }

    // --------------------------------------------------------------------

    /**
     * Is AJAX request?
     *
     * Test to see if a request contains the HTTP_X_REQUESTED_WITH header.
     *
     * @return     bool
     */
    public function is_ajax_request()
    {
        return ( ! empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) === 'xmlhttprequest');
    }

    // --------------------------------------------------------------------

    /**
     * Is CLI request?
     *
     * Test to see if a request was made from the command line.
     *
     * @deprecated    3.0.0    Use is_cli() instead
     * @return    bool
     */
    public function is_cli_request()
    {
        return is_cli();
    }

    // --------------------------------------------------------------------

    /**
     * Get Request Method
     *
     * Return the request method
     *
     * @param    bool    $upper    Whether to return in upper or lower case
     *                (default: FALSE)
     * @return     string
     */
    public function method($upper = FALSE)
    {
        return ($upper)
            ? strtoupper($this->server('REQUEST_METHOD'))
            : strtolower($this->server('REQUEST_METHOD'));
    }

    // ------------------------------------------------------------------------

    /**
     * Magic __get()
     *
     * Allows read access to protected properties
     *
     * @param    string    $name
     * @return    mixed
     */
    public function __get($name)
    {
        if ($name === 'raw_input_stream')
        {
            isset($this->_raw_input_stream) OR $this->_raw_input_stream = file_get_contents('php://input');
            return $this->_raw_input_stream;
        }
        elseif ($name === 'ip_address')
        {
            return $this->ip_address;
        }
    }

}


文章作者: Fengit
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