Here's what I came up with to remove magic quotes from request data.
Replaces two single-quotes with one if magic_quotes_sybase are on, otherwise it just strips slashes.
Note that the `foreach` style makes this work only with PHP 5 and above.
<?php
// Strip magic quotes from request data.
if (function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc()) {
// Create lamba style unescaping function (for portability)
$quotes_sybase = strtolower(ini_get('magic_quotes_sybase'));
$unescape_function = (empty($quotes_sybase) || $quotes_sybase === 'off') ? 'stripslashes($value)' : 'str_replace("\'\'","\'",$value)';
$stripslashes_deep = create_function('&$value, $fn', '
if (is_string($value)) {
$value = ' . $unescape_function . ';
} else if (is_array($value)) {
foreach ($value as &$v) $fn($v, $fn);
}
');
// Unescape data
$stripslashes_deep($_POST, $stripslashes_deep);
$stripslashes_deep($_GET, $stripslashes_deep);
$stripslashes_deep($_COOKIE, $stripslashes_deep);
$stripslashes_deep($_REQUEST, $stripslashes_deep);
}
?>
get_magic_quotes_gpc
(PHP 4, PHP 5, PHP 7)
get_magic_quotes_gpc — Restituisce l'attuale configurazione di magic_quotes_gpc
Avviso
This function has been DEPRECATED as of PHP 7.4.0, and REMOVED as of PHP 8.0.0. Relying on this function is highly discouraged.
Valori restituiti
Restituisce sempre false.
Log delle modifiche
| Versione | Descrizione |
|---|---|
| 7.4.0 | Questa funzione รจ stata deprecata. |
Vedere anche:
- addslashes() - Esegue il quoting di una stringa con gli slash
- stripslashes() - Rimuove gli slash aggiunti con addslashes
- get_magic_quotes_runtime() - Restituisce l'impostazione corrente della direttiva magic_quotes_runtime
- ini_get() - Restituisce il valore delle opzioni di configurazione
add a note
User Contributed Notes 10 notes
hetored at gmail dot com ¶
14 years ago
php at kaiundina dot de ¶
19 years ago
Escaping of key-strings in GPC-arrays behave different to the escaping of their values.
First I expected that keys in submitted gpc-arrays are never escaped.
Anyway. After I saw escaped keys, I assumed they're escaped according to the settings of magic quotes.
... it's even worse...
It took me over 2 days of testing to figure out the exact behavior and creating two functions (one for each php-version) that strips slashes reliably from any array submitted to a script. Hope this saves someones time and nerves.
The following is true for $_GET- and $_POST-arrays. I hope other arrays affected by magic quotes behave equally.
I did not test the behavior for cases where magic_quotes_sybase is set.
== legend for possible case combinations ==
Px = php version we're using
P4 = php 4.3.9
P5 = php 5.0.2
MQ = MagicQuotes GPC
+MQ = magic quotes enabled
-MQ = magic quotes disabled
TL = TopLevel key
+TL = key is on top level (i.e. $_GET['myKey'])
-TL = key is nested within another array (i.e. $_GET['myList']['myKey'])
AK = ArrayKey
+AK = the value of the key is another array (i.e. is_array($_GET['myKey']) == true)
-AK = the value is a normal string (i.e. is_string($_GET['myKey']) == true)
== legend for possible results ==
KE = KeyEscaping
+KE = control chars are prefixed with a backslash
-KE = key is returned as submitted and needn't to be stripped
VE = ValueEscaping (doesn't apply for array as value)
+VE = control chars are prefixed with a backslash
-VE = value is returned as submitted and needn't to be stripped
== here we go - the following rules apply ==
1) P4 +MQ +AK +TL --> -KE
2) P4 +MQ +AK -TL --> +KE
3) P4 +MQ -AK +TL --> -KE +VE
4) P4 +MQ -AK -TL --> +KE +VE
5) P4 -MQ +AK +TL --> -KE
6) P4 -MQ +AK -TL --> -KE
7) P4 -MQ -AK +TL --> -KE -VE
8) P4 -MQ -AK -TL --> -KE -VE
9) P5 +MQ +AK +TL --> -KE
10) P5 +MQ +AK -TL --> +KE
11) P5 +MQ -AK +TL --> +KE +VE
12) P5 +MQ -AK -TL --> +KE +VE
13) P5 -MQ +AK +TL --> -KE
14) P5 -MQ +AK -TL --> -KE
15) P5 -MQ -AK +TL --> +KE -VE
16) P5 -MQ -AK -TL --> +KE -VE
17) The chars '.', ' ' are always replaced by '_' when used in keys.
Example (rule 15):
When running under php 5.0.2 having magic quotes disabled, gpc-keys on top level containing strings are escaped while their associated values are not.
== The following function will strip GPC-arrays for php 4.3.9 ==
<?php
function transcribe($aList, $aIsTopLevel = true) {
$gpcList = array();
$isMagic = get_magic_quotes_gpc();
foreach ($aList as $key => $value) {
$decodedKey = ($isMagic && !$aIsTopLevel)?stripslashes($key):$key;
if (is_array($value)) {
$decodedValue = transcribe($value, false);
} else {
$decodedValue = ($isMagic)?stripslashes($value):$value;
}
$gpcList[$decodedKey] = $decodedValue;
}
return $gpcList;
}
?>
== The following function will strip GPC-arrays for php 5.0.2 ==
<?php
function transcribe($aList, $aIsTopLevel = true) {
$gpcList = array();
$isMagic = get_magic_quotes_gpc();
foreach ($aList as $key => $value) {
if (is_array($value)) {
$decodedKey = ($isMagic && !$aIsTopLevel)?stripslashes($key):$key;
$decodedValue = transcribe($value, false);
} else {
$decodedKey = stripslashes($key);
$decodedValue = ($isMagic)?stripslashes($value):$value;
}
$gpcList[$decodedKey] = $decodedValue;
}
return $gpcList;
}
?>
Usage:
<?php
$unstrippedGET = transcribe($_GET);
$unstrippedPOST = transcribe($_POST);
?>
Maybe someone is willing to test those combinations for other php-versions and with magic_quotes_sybase set to 'on' - let me know.
Sorry for this huge amount of text, but it's complete. I was unable to compress the decision table more than this.
eltehaem at poczta dot onet dot pl ¶
19 years ago
Please note, that when magic_quotes_gpc is set not only $_POST, $_GET, $_REQUEST, $_COOKIE arrays values are slashed. Actually every string value in $GLOBALS array is slashed, ie. $GLOBALS['_SERVER']['PATH_INFO'] (or $_SERVER['PATH_INFO']).
louis at greynoise dot co dot uk ¶
16 years ago
<?php
function stripper($stringvar){
if (1 == get_magic_quotes_gpc()){
$stringvar = stripslashes($stringvar);
}
return $stringvar;
}
?>
Usage:
<?php
$Body = stripper($rs->fields('Body'));
echo($Body);
?>
This checks if get_magic_quotes_gpc() is on and strips a string variable for output if its on. Useful if the dev server and live server are set up different.
slonmron_no_spam_please_ at yahoo dot com ¶
17 years ago
Re: php at kaiundina dot de (03-Feb-2005 02:18)
1. magic_quotes_gpc=on/off and magic_quotes_sybase=on/off
I made test and your function worked right.
These were the <input ... /> names I used:
name="a"
name="b.b b\b"
name="c[c.1]"
name="c[c 2]"
name="c[c\3]"
name="c.c c[c.' 4]"
name="c ' c[c"4]"
name="d"[d"1]"
(I used " because I don't know other way to put " into the name)
and the user-input value:
a ' " \ \' \" \\ a
2. > 17) The chars '.', ' ' are always replaced by '_' when used in keys.
This is true only for the top-level keys, such as "b.b b\b", "c.c c" and "c ' c" above. The second-level key "[c.' 4]" was not changed to [c_'_4] but was escaped acording to how magic_quites_XXX are set.
Tested on PHP 4.4.0.
These magic_quotes are really black magic :(
It'll be good to make test against $_SESSION, but I can't do it today.
venimus at gmail dot com ¶
18 years ago
When you work with forms and databases you should use this concept:
1.When inserting the user input in DB escape $_POST/$_GET with add_slashes() or similar (to match the speciffic database escape rules)
$query='INSERT INTO users SET fullname="'.add_slashes($_POST['fullname']).'"';
insert_into_db($query);
2.When reading a previously submitted input from DB use html_special_chars to display an escaped result!
read_db_row('SELECT fullname FROM users');
echo '<input type="text" name="fullname" value="'.html_special_chars($db_row['fullname']).'" />
this way you safely store and work with the original(unescaped) data.
heiko dot richler at informatik dot fh-nuernberg dot de ¶
16 years ago
@ dot dot dot dot dot alexander at gmail dot com
I suggest replacing foreach by "stripslashes_deep":
Example #2 Using stripslashes() on an array on
<http://www.php.net/manual/en/function.stripslashes.php>:
<?php
function stripslashes_deep($value)
{
$value = is_array($value) ?
array_map('stripslashes_deep', $value) :
stripslashes($value);
return $value;
}
?>
This gives:
<?php
if((function_exists("get_magic_quotes_gpc") && get_magic_quotes_gpc()) || (ini_get('magic_quotes_sybase') && (strtolower(ini_get('magic_quotes_sybase'))!="off")) ){
stripslashes_deep($_GET);
stripslashes_deep($_POST);
stripslashes_deep($_COOKIE);
}
?>
dot dot dot dot dot alexander at gmail dot com ¶
16 years ago
Just a little correction:
( Because of the ini_get function that may return a string value of "off" that evaluates to TRUE )
<?php
if(
( function_exists("get_magic_quotes_gpc") && get_magic_quotes_gpc() )
|| ( ini_get('magic_quotes_sybase') && ( strtolower(ini_get('magic_quotes_sybase')) != "off" ) )
){
foreach($_GET as $k => $v) $_GET[$k] = stripslashes($v);
foreach($_POST as $k => $v) $_POST[$k] = stripslashes($v);
foreach($_COOKIE as $k => $v) $_COOKIE[$k] = stripslashes($v);
}
?>
w3dk ¶
9 years ago
> "If the directive magic_quotes_sybase is ON it will completely override magic_quotes_gpc."
This "note" is a bit misleading. magic_quotes_sybase will only override the escaping method used on Get/Post/Cookie data if magic_quotes_gpc is already enabled. If magic_quotes_gpc is not enabled then magic_quotes_sybase will have no effect here.
A few of the other comments are therefore incorrect in determining when to "stripslashes" from the input, by "stripping slashes" when either magic_quotes_gpc OR magic_quotes_sybase is enabled. You should only stripslashes() when magic_quotes_gpc is enabled since that is the only time when slashes are automatically added.
stripslashes() is also magic_quotes_sybase aware, so you don't need to do anything special (ie. write a custom function to handle this situation as another comment suggests) when magic_quotes_sybase is enabled. When magic_quotes_sybase is enabled, stripslashes() does not actually strip any slashes, but instead unescapes single-quotes that are escaped with single-quotes only.
magic_quotes_sybase does however influence the escaping (and unescaping) method used by addslashes() and stripslashes() respectively, regardless of whether magic_quotes_gpc (or magic_quotes_runtime) is enabled.
rogier at dsone ¶
12 years ago
Regarding the three main strip methods as found below (two using foreach, 1 using the json method), I've done a little benchmarking using 'true' profiling (using a registered tickhandler where declare(ticks=1)).
I wondered whether or not json would not be terribly slow.
I won't discuss the profiler, but will suffice with the following statement, followed by the used code to benchmark:
The json method was by FAR the quickest (contrary to what I'd thought), so if you need a speedy process, use that!
<?php
declare(ticks=1);
function g()
{
return array(
'a'=>'i\\\\\\'m',
array('a1' => 'x', 'b1' => 'x'),
array( 'a2' => array('a3' => '\\\\\\'x', 'b3' => 'random' )
)
);
}
function strip_json($d)
{
$rs = json_decode(stripslashes(json_encode($d, JSON_HEX_APOS)), true);
return $rs;
}
function strip_deep1($d)
{
foreach ($d as $k=>$v)
{
if (is_array($v)) { $d[$k] = strip_deep1($v); }
else { $d[$k] = stripslashes($v); }
}
return $d;
}
function strip_deep2(&$d)
{
$d = is_array($d) ? array_map('strip_deep2', $d) : stripslashes($d);
return $d;
}
// now profile it
require_once './TickProfiler.php';
$N = 1000;
$d = g();
TickProfiler::Register();
for ($i = 0; $i < $N; $i++){ strip_json($d); }
for ($i = 0; $i < $N; $i++){ strip_deep1($d); }
for ($i = 0; $i < $N; $i++){ strip_deep2($d); }
TickProfiler::Unregister();
TickProfiler::Display();
?>
My output (PHP 5.3.1, win32):
[TickProfiler::tick] => Array
(
[time] => 0.76188707351685
[calls] => 46001
)
[TickProfiler::Register] => Array
(
[time] => 3.0994415283203E-5
[calls] => 1
)
[strip_json] => Array
(
[time] => 0.025638580322266
[calls] => 1000
)
[strip_deep1] => Array
(
[time] => 0.40303444862366
[calls] => 36000
)
[strip_deep2] => Array
(
[time] => 0.14928555488586
[calls] => 9000
)
)
As can be seen above, using json speeds output by at least a factor of 5 (nearly 6).
Just wanted to share this :D
Do note the strip_json function has two LOC instead of a plain return statement, otherwise it wouldn't get picked up by the tickprofiler (it would return from the code immediately, never reaching the profiler)!
Usage of the return statement in strip_deep2 is not needed, as the argument is passed by reference.
A new test showed that the time penalty for this is about 0.09 seconds.
This actually means that the factor between strip_deep2 vs strip_json is only about 2.
Still, strip_json would be about twice as fast as strip_deep2
