unserialize in php not return any value

Question

I am unserializing below string but its not returning anything.

a:57:{s:10:"THEME_NAME";s:5:"green";s:16:"PUBLIC_ADS_LIMIT";s:1:"5";s:17:"PUBLIC_EDIT_LIMIT";s:1:"5";s:8:"SITENAME";s:10:"Abcdubai";s:5:";}

Answer 1

The data you're unserializing is wrong

a:57{s:10:"THEME_NAME";s:5:"green";s:16:"PUBLIC_ADS_LIMIT";s:1:"5";s:17:"PUBLIC_EDIT_LIMIT";s:1:"5";s:8:"SITENAME";s:10:"Abcdubai";s:5:";}

if you try to unserialize it with error reporting E_ALL you will see a notice

$data = 'a:57{s:10:"THEME_NAME";s:5:"green";s:16:"PUBLIC_ADS_LIMIT";s:1:"5";s:17:"PUBLIC_EDIT_LIMIT";s:1:"5";s:8:"SITENAME";s:10:"Abcdubai";s:5:";}';

var_dump($data);

you will get

Notice: unserialize(): Error

because

• a:57 is the array length and from the data you have it's clearly not 57.

• s: points to the length of string s:10:"Abcdubai" the string Abcdubai is not 10 in length it's 8 so you need to change that to s:8:"Abcdubai"

• Finally you have s:5:"; at the end for the same reason s:5 means a string with 5 characters in length and it's empty with a one double quote

  <?php
  // this the valid data
   $data = 'a:4:{s:10:"THEME_NAME";s:5:"green";s:16:"PUBLIC_ADS_LIMIT";s:1:"5";s:17:"PUBLIC_EDIT_LIMIT";s:1:"5";s:8:"SITENAME";s:8:"Abcdubai";}';
  
  $data = unserialize($data);
  
  // accessing the valid serialized data
  echo $data['THEME_NAME'];
  echo $data['PUBLIC_ADS_LIMIT'];
  echo $data['PUBLIC_EDIT_LIMIT'];
  echo $data['SITENAME']; 
  

you can try this method to solve formatting issues

   function fixUnserializeFormatting($data){
       // fix string length (will fix s:)
       $data = preg_replace('!s:(\d+):"(.*?)";!e', "'s:'.strlen('$2').':\"$2\";'", $data);
       // remove empty matches with one double qoute
       $data = preg_replace('/s\:+[0-9]+\:";/i', '', $data);

       // trying to get the right array length
       $strings = substr_count($data,';') / 2;        
       // fixing array length
       $data = preg_replace('/^a:+[0-9]+:/i', "a:{$strings}:", $data);

       // finally returning the formatted data
       return $data;    
   }

Usage

   $data = 'a:57:{s:10:"THEME_NAME";s:5:"green";s:16:"PUBLIC_ADS_LIMIT";s:1:"5";s:17:"PUBLIC_EDIT_LIMIT";s:1:"5";s:8:"SITENAME";s:10:"Abcdubai";s:5:";}';

   $data = fixUnserializeFormatting($data);

   var_dump(unserialize($data));