Here are some useful functions to convert large hex numbers from and to large decimal ones :
<?php
public static function bchexdec($hex) {
if(strlen($hex) == 1) {
return hexdec($hex);
} else {
$remain = substr($hex, 0, -1);
$last = substr($hex, -1);
return bcadd(bcmul(16, bchexdec($remain)), hexdec($last));
}
}
public static function bcdechex($dec) {
$last = bcmod($dec, 16);
$remain = bcdiv(bcsub($dec, $last), 16);
if($remain == 0) {
return dechex($last);
} else {
return bcdechex($remain).dechex($last);
}
}
