How to repair a serialized string which has been corrupted by an incorrect byte count length?
I am using Hotaru CMS with the Image Upload plugin, I get this error if I try to attach an image to a post, otherwise there is no error:
unserialize() [function.unserialize]: Error at offset
The offending code (error points to line with **):
/**
* Retrieve submission step data
*
* @param $key - empty when setting
* @return bool
*/
public function loadSubmitData($h, $key = '')
{
// delete everything in this table older than 30 minutes:
$this->deleteTempData($h->db);
if (!$key) { return false; }
$cleanKey = preg_replace('/[^a-z0-9]+/','',$key);
if (strcmp($key,$cleanKey) != 0) {
return false;
} else {
$sql = "SELECT tempdata_value FROM " . TABLE_TEMPDATA . " WHERE tempdata_key = %s ORDER BY tempdata_updatedts DESC LIMIT 1";
$submitted_data = $h->db->get_var($h->db->prepare($sql, $key));
**if ($submitted_data) { return unserialize($submitted_data); } else { return false; }**
}
}
Data from the table, notice the end bit has the image info, I am not an expert in PHP so I was wondering what you guys/gals might think?
tempdata_value:
a:10:{s:16:"submit_editorial";b:0;s:15:"submit_orig_url";s:13:"www.bbc.co.uk";s:12:"submit_title";s:14:"No title found";s:14:"submit_content";s:12:"dnfsdkfjdfdf";s:15:"submit_category";i:2;s:11:"submit_tags";s:3:"bbc";s:9:"submit_id";b:0;s:16:"submit_subscribe";i:0;s:15:"submit_comments";s:4:"open";s:5:"image";s:19:"C:fakepath100.jpg";}
Edit: I think I've found the serialize bit...
/**
* Save submission step data
*
* @return bool
*/
public function saveSubmitData($h)
{
// delete everything in this table older than 30 minutes:
$this->deleteTempData($h->db);
$sid = preg_replace('/[^a-z0-9]+/i', '', session_id());
$key = md5(microtime() . $sid . rand());
$sql = "INSERT INTO " . TABLE_TEMPDATA . " (tempdata_key, tempdata_value, tempdata_updateby) VALUES (%s,%s, %d)";
$h->db->query($h->db->prepare($sql, $key, serialize($h->vars['submitted_data']), $h->currentUser->id));
return $key;
}
Answer
unserialize() [function.unserialize]: Error at offset was dues to invalid serialization data due to invalid length
Quick Fix
What you can do is is recalculating the length of the elements in serialized array
You current serialized data
$data = 'a:10:{s:16:"submit_editorial";b:0;s:15:"submit_orig_url";s:13:"www.bbc.co.uk";s:12:"submit_title";s:14:"No title found";s:14:"submit_content";s:12:"dnfsdkfjdfdf";s:15:"submit_category";i:2;s:11:"submit_tags";s:3:"bbc";s:9:"submit_id";b:0;s:16:"submit_subscribe";i:0;s:15:"submit_comments";s:4:"open";s:5:"image";s:19:"C:fakepath100.jpg";}';
Example without recalculation
var_dump(unserialize($data));
Output
Notice: unserialize() [function.unserialize]: Error at offset 337 of 338 bytes
Recalculating
$data = preg_replace('!s:(\d+):"(.*?)";!e', "'s:'.strlen('$2').':\"$2\";'", $data);
var_dump(unserialize($data));
Output
array
'submit_editorial' => boolean false
'submit_orig_url' => string 'www.bbc.co.uk' (length=13)
'submit_title' => string 'No title found' (length=14)
'submit_content' => string 'dnfsdkfjdfdf' (length=12)
'submit_category' => int 2
'submit_tags' => string 'bbc' (length=3)
'submit_id' => boolean false
'submit_subscribe' => int 0
'submit_comments' => string 'open' (length=4)
'image' => string 'C:fakepath100.jpg' (length=17)
Recommendation .. I
Instead of using this kind of quick fix ... i"ll advice you update the question with
How you are serializing your data
How you are Saving it ..
================================ EDIT 1 ===============================
The Error
The Error was generated because of use of double quote " instead single quote ' that is why C:\fakepath\100.png was converted to C:fakepath100.jpg
To fix the error
You need to change $h->vars['submitted_data'] From (Note the singe quite ' )
Replace
$h->vars['submitted_data']['image'] = "C:\fakepath\100.png" ;
With
$h->vars['submitted_data']['image'] = 'C:\fakepath\100.png' ;
Additional Filter
You can also add this simple filter before you call serialize
function satitize(&$value, $key)
{
$value = addslashes($value);
}
array_walk($h->vars['submitted_data'], "satitize");
If you have UTF Characters you can also run
$h->vars['submitted_data'] = array_map("utf8_encode",$h->vars['submitted_data']);
How to detect the problem in future serialized data
findSerializeError ( $data1 ) ;
Output
Diffrence 9 != 7
-> ORD number 57 != 55
-> Line Number = 315
-> Section Data1 = pen";s:5:"image";s:19:"C:fakepath100.jpg
-> Section Data2 = pen";s:5:"image";s:17:"C:fakepath100.jpg
^------- The Error (Element Length)
findSerializeError Function
function findSerializeError($data1) {
echo "<pre>";
$data2 = preg_replace ( '!s:(\d+):"(.*?)";!e', "'s:'.strlen('$2').':\"$2\";'",$data1 );
$max = (strlen ( $data1 ) > strlen ( $data2 )) ? strlen ( $data1 ) : strlen ( $data2 );
echo $data1 . PHP_EOL;
echo $data2 . PHP_EOL;
for($i = 0; $i < $max; $i ++) {
if (@$data1 {$i} !== @$data2 {$i}) {
echo "Diffrence ", @$data1 {$i}, " != ", @$data2 {$i}, PHP_EOL;
echo "\t-> ORD number ", ord ( @$data1 {$i} ), " != ", ord ( @$data2 {$i} ), PHP_EOL;
echo "\t-> Line Number = $i" . PHP_EOL;
$start = ($i - 20);
$start = ($start < 0) ? 0 : $start;
$length = 40;
$point = $max - $i;
if ($point < 20) {
$rlength = 1;
$rpoint = - $point;
} else {
$rpoint = $length - 20;
$rlength = 1;
}
echo "\t-> Section Data1 = ", substr_replace ( substr ( $data1, $start, $length ), "<b style=\"color:green\">{$data1 {$i}}</b>", $rpoint, $rlength ), PHP_EOL;
echo "\t-> Section Data2 = ", substr_replace ( substr ( $data2, $start, $length ), "<b style=\"color:red\">{$data2 {$i}}</b>", $rpoint, $rlength ), PHP_EOL;
}
}
}
A better way to save to Database
$toDatabse = base64_encode(serialize($data)); // Save to database
$fromDatabase = unserialize(base64_decode($data)); //Getting Save Format