function iban_verify_checksum($iban)
{
# convert to machine format
$iban = iban_to_machine_format($iban);
# move first 4 chars (countrycode and checksum) to the end of the string
$tempiban = substr($iban, 4) . substr($iban, 0, 4);
# subsitutute chars
$tempiban = iban_checksum_string_replace($tempiban);
# mod97-10
$result = iban_mod97_10($tempiban);
# checkvalue of 1 indicates correct IBAN checksum
if ($result != 1) {
return false;
}
return true;
}
function iban_find_checksum($iban)
{
$iban = iban_to_machine_format($iban);
# move first 4 chars to right
$left = substr($iban, 0, 2) . '00';
# but set right-most 2 (checksum) to '00'
$right = substr($iban, 4);
# glue back together
$tmp = $right . $left;
# convert letters using conversion table
$tmp = iban_checksum_string_replace($tmp);
# get mod97-10 output
$checksum = iban_mod97_10($tmp);
return str_pad(98 - $checksum, 2, '0', STR_PAD_LEFT);
}
