ID:          42718
 Updated by:  [EMAIL PROTECTED]
 Reported By: arnaud dot lb at gmail dot com
-Status:      Open
+Status:      Feedback
 Bug Type:    Filter related
 PHP Version: 5.2.4
-Assigned To: 
+Assigned To: pajoye
 New Comment:

"The unsafe_raw filter does nothing by default, but it 
can "optionally strip or encode special characters", and it is the 
only filter which is able to do that without doing any other 
filtering."

The string filter with the correct flags should work as you expected.
It is normal that the unsafe_raw filter does nothing.

What are you trying to achieve exactly? (ie using other filters but it
did not work as you expect)


Previous Comments:
------------------------------------------------------------------------

[2007-09-24 17:37:09] arnaud dot lb at gmail dot com

I made a little (one-line) patch for this bug:
https://s3.amazonaws.com/arnaud.lb/filter-bug-42718.patch.txt

And a testcase:
https://s3.amazonaws.com/arnaud.lb/bug42718.phpt.txt

And an other test case to check if the patch does not modify the 
behavior of the php_sapi_filter() function:

- Apply filter, only if filter will do something (unsafe_raw with no 
flags do nothing)
- Else, fallback to magic_quotes_gpc if enabled

https://s3.amazonaws.com/arnaud.lb/052.phpt.txt

------------------------------------------------------------------------

[2007-09-20 16:54:55] arnaud dot lb at gmail dot com

Description:
------------
The "unsafe_raw" filter is not applied when configured as default 
filter.

I found that the php_sapi_filter() internal function in 
ext/filter/filter.c intentionally bypass this filter:

if (!(IF_G(default_filter) == FILTER_UNSAFE_RAW)){
 (apply default filter)
} else [...]

The unsafe_raw filter does nothing by default, but it 
can "optionally strip or encode special characters", and it is the 
only filter which is able to do that without doing any other 
filtering.

Reproduce code:
---------------
- Prints filter.default and filter.default_flags values,
- Check if $_GET['a'] contains a null byte (null bytes may be filtered
by FILTER_UNSAFE_RAW with the FILTER_FLAG_STRIP_LOW flag
- Check if $_GET['a'] though filter_input() with the same filter/flags
contains a null byte.

<?php
echo "filter.default = " . ini_get('filter.default') . " <br />\n";
echo "filter.default_flags = " . ini_get('filter.default_flags') . "
<br />\n";
echo "<br />";
echo "\$_GET['a'] contains \\0: " . (strpos($_GET['a'], "\0") !== false
? 'Yes' : 'No') . " <br />\n";
echo "<br />";
echo "\$_GET['a'] throught filter_var() contains \\0: " .
(strpos(filter_var($_GET['a'], FILTER_UNSAFE_RAW,
FILTER_FLAG_STRIP_LOW), "\0") !== false ? 'Yes' : 'No') . "<br />";
echo "<br />";
?>

Expected result:
----------------
filter.default: unsafe_raw
filter.default_flags: 4

$_GET['a'] contains \0: No

$_GET['a'] through filter_var() contains \0: No

Actual result:
--------------
filter.default: unsafe_raw
filter.default_flags: 4

$_GET['a'] contains \0: Yes

$_GET['a'] through filter_var() contains \0: No


------------------------------------------------------------------------


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