function pad_message($str)
{
$strlen = strlen($str);
// NOTE: 8 is the size in bits of a byte (single char string)
$l = $strlen * 8;
$bitstr = "";
for ($i = 0; $i < $strlen; $i++) {
$tmp = substr($str, $i, 1);
echo "char [" . $tmp . "] ord [" . ord($tmp) . "] decbin[" . decbin(ord($tmp)) . "]\n";
$tmp = decbin(ord($tmp));
$tmp = str_pad($tmp, 8, 0, STR_PAD_LEFT);
$bitstr .= $tmp;
}
// Append 1 bit
$bitstr .= "1";
echo "bitstring:" . $bitstr . "\n";
echo "int_pad_len:" . ($l + 1 + 64) % 512 . "\n";
$padlen = 512 - ($l + 1 + 64) % 512;
echo "pad_len:" . $padlen . "\n";
$padding = str_pad($padding, $padlen, 0);
$bitstr .= $padding;
// Calculate 64 bit length
$tmp = new BigInt($l);
$bitstr .= str_pad($tmp->ToString(), 64, "0", STR_PAD_LEFT);
$blocks = strlen($bitstr) / 512;
$ret = array();
for ($i = 0; $i < $blocks; $i++) {
$ret[$i] = substr($bitstr, $i * 512, 512);
}
return $ret;
}
