Help Desk password hash

[lenobles]

I tried tosearch, but found no topics about this hash. Is is possible to use some rules or something else to Help Desk's hashing algoritm? It uses only sha1, but pre-hashing every symbols in password.

Function:

PHP Code:

function hesk_Pass2Hash($plaintext) {
   $majorsalt  = '';
   $len = strlen($plaintext);
   for ($i=0;$i<$len;$i++)
   {
       $majorsalt .= sha1(substr($plaintext,$i,1));
   }
   $corehash = sha1($majorsalt);
   return $corehash;
} 


I can convert wordlists to something like pre-rainbow tables, where each line is result of final $majorsalt (name from code example) and then put it to hashcat as wordlist, but it's not so fast...