phpmyadmin/libraries/grab_globals.lib.php

<?php
/* $Id$ */
// vim: expandtab sw=4 ts=4 sts=4:


/**
 * This library grabs the names and values of the variables sent or posted to a
 * script in the $_* arrays and sets simple globals variables from them. It does
 * the same work for the $PHP_SELF, $HTTP_ACCEPT_LANGUAGE and
 * $HTTP_AUTHORIZATION variables.
 *
 * loic1 - 2001/25/11: use the new globals arrays defined with php 4.1+
 */

/**
 * check if a subform is submitted
 */
$__redirect = NULL;
if ( isset( $_POST['usesubform'] ) ) {
    // if a subform is present and should be used
    // the rest of the form is deprecated
    $subform_id = key( $_POST['usesubform'] );
    $subform    = $_POST['subform'][$subform_id];
    $_POST      = $subform;
    if ( isset( $_POST['redirect'] )
      && $_POST['redirect'] != basename( $_SERVER['PHP_SELF'] ) ) {
        $__redirect = $_POST['redirect'];
        unset( $_POST['redirect'] );
    } // end if ( isset( $_POST['redirect'] ) )
    unset( $subform_id, $subform );
} // end if ( isset( $_POST['usesubform'] ) )
// end check if a subform is submitted

if ( $__redirect || ! defined( 'PMA_NO_VARIABLES_IMPORT' ) ) {
    /**
     * copy values from one array to another, usally from a superglobal into $GLOBALS
     *
     * @uses    $GLOBALS['_import_blacklist']
     * @uses    preg_replace()
     * @uses    array_keys()
     * @uses    array_unique()
     * @uses    get_magic_quotes_gpc()  to check wether stripslashes or not
     * @uses    stripslashes()
     * @param   array   $array      values from
     * @param   array   $target     values to
     * @param   boolean $sanitize   prevent importing key names in $_import_blacklist
     */
    function PMA_gpc_extract($array, &$target, $sanitize = TRUE) {
        if (!is_array($array)) {
            return FALSE;
        }

        if ( $sanitize ) {
            $valid_variables = preg_replace( $GLOBALS['_import_blacklist'], '',
                array_keys( $array ) );
            $valid_variables = array_unique( $valid_variables );
        } else {
            $valid_variables = array_keys( $array );
        }

        $is_magic_quotes = get_magic_quotes_gpc();

        foreach ( $valid_variables as $key ) {

            if ( strlen( $key ) === 0 ) {
                continue;
            }

            if ( is_array( $array[$key] ) ) {
                // there could be a variable coming from a cookie of
                // another application, with the same name as this array
                unset($target[$key]);

                PMA_gpc_extract($array[$key], $target[$key], FALSE);
            } elseif ($is_magic_quotes) {
                $target[$key] = stripslashes($array[$key]);
            } else {
                $target[$key] = $array[$key];
            }
        }
        return TRUE;
    }


    /**
     * @var array $_import_blacklist variable names that should NEVER be imported
     *                              from superglobals
     */
    $_import_blacklist = array(
        '/^cfg$/i',      // PMA configuration
        '/^GLOBALS$/i',  // the global scope
        '/^str.*$/i',    // PMA strings
        '/^_.*$/i',      // PMA does not use variables starting with _ from extern
        '/^.*\s+.*$/i',  // no whitespaces anywhere
        '/^[0-9]+.*$/i', // numeric variable names
        //'/^PMA_.*$/i',   // other PMA variables
    );

    if (!empty($_GET)) {
        PMA_gpc_extract($_GET, $GLOBALS);
    } // end if

    if (!empty($_POST)) {
        PMA_gpc_extract($_POST, $GLOBALS);
    } // end if (!empty($_POST))

    if (!empty($_FILES)) {
        foreach ($_FILES AS $name => $value) {
            $$name = $value['tmp_name'];
            ${$name . '_name'} = $value['name'];
        }
        unset( $name, $value );
    } // end if

    if (!empty($_SERVER)) {
        $server_vars = array('PHP_SELF', 'HTTP_ACCEPT_LANGUAGE', 'HTTP_AUTHORIZATION');
        foreach ( $server_vars as $current ) {
            // its not important HOW we detect html tags
            // its more important to prevent XSS
            // so its not important if we result in an invalid string,
            // its even better than a XSS capable string
            if ( isset( $_SERVER[$current] ) && false === strpos( $_SERVER[$current], '<' ) ) {
                $$current = $_SERVER[$current];
            // already importet by register_globals?
            } elseif ( ! isset( $$current ) || false !== strpos( $$current, '<' ) ) {
                $$current = '';
            }
        }
        unset( $server_vars, $current );
    } // end if

    // Security fix: disallow accessing serious server files via "?goto="
    if (isset($goto) && strpos(' ' . $goto, '/') > 0 && substr($goto, 0, 2) != './') {
        unset($goto);
    } // end if

    unset( $_import_blacklist );

    if ( ! empty( $__redirect ) ) {
        // TODO: ensure that PMA_securePath() is defined and available
        // for this script. Meanwhile we duplicate what this function does:
        require('./' . preg_replace('@\.\.*@','.',$__redirect));
        exit();
    } // end if ( ! empty( $__redirect ) )

} else {

    // Security fix: disallow accessing serious server files via "?goto="
    if ( isset( $_REQUEST['goto'] )
      && strpos( $_REQUEST['goto'], '\\' ) !== false
      && strpos( $_REQUEST['goto'], '/' ) !== false ) {
        unset( $_REQUEST['goto'], $_GET['goto'], $_POST['goto'],
            $_COOKIE['goto'] );
    } // end if

    /**
     * Recursive wrapper around strip_tags to process also arrays.
     *
     * @param   mixed   array or string to strip tags
     */
    function array_strip_tags(&$item) {
        if (is_array($item)) {
            array_walk($item, 'array_strip_tags');
        } else {
            strip_tags($item);
        }
    }

    array_walk( $_SERVER, 'array_strip_tags' );
    array_walk( $_ENV, 'array_strip_tags' );

}
?>