just copied from this site
http://www.busindre.com/exploits-para-encriptacion-tipo-7-de-cisco-escritos-en-c-perl-y-javascript/
I like javascript, so I use this.
function isDigit(theDigit)
{
var digitArray = new Array('0','1','2','3','4','5','6','7','8','9')
for (j = 0; jif (theDigit == digitArray[j])
return true
}
return false
}
// Generate a config file ready for loading
function crackPassword(form)
{
var crypttext=form.crypttext.value.toUpperCase()
var plaintext=''
var xlat="dsfd;kfoA,.iyewrkldJKDHSUBsgvca69834ncxv9873254k;fg87"
var seed, i, val=0
if(crypttext.length & 1)
return
seed = (crypttext.charCodeAt(0) - 0x30) * 10 + crypttext.charCodeAt(1) - 0x30
if (seed> 15 || !isDigit(crypttext.charAt(0)) || !isDigit(crypttext.charAt(1)))
return
for (i = 2 ; i <= crypttext.length; i++) {
if(i !=2 && !(i & 1)) {
plaintext+=String.fromCharCode(val ^ xlat.charCodeAt(seed++))
seed%=xlat.length
val = 0;
}
val *= 16
if(isDigit(crypttext.charAt(i))) {
val += crypttext.charCodeAt(i) - 0x30
continue
}
if(crypttext.charCodeAt(i)>= 0x41 && crypttext.charCodeAt(i) <= 0x46) {
val += crypttext.charCodeAt(i) - 0x41 + 0x0a
continue
}
if(crypttext.length != i)
return
}
form.plaintext.value=plaintext
}