my $data = substr($hdl->{rbuf}, 0, $offset + 4 + $payload_len, ''); # now consume data
- my @mask = (unpack('C', substr($data, $offset+0, 1)),
- unpack('C', substr($data, $offset+1, 1)),
- unpack('C', substr($data, $offset+2, 1)),
- unpack('C', substr($data, $offset+3, 1)));
-
+ my $mask = substr($data, $offset, 4);
$offset += 4;
my $payload = substr($data, $offset, $payload_len);
- for (my $i = 0; $i < $payload_len; $i++) {
- my $d = unpack('C', substr($payload, $i, 1));
- my $n = $d ^ $mask[$i % 4];
- substr($payload, $i, 1, pack('C', $n));
+ # NULL-mask might be used over TLS, skip to increase performance
+ if ($mask ne pack('N', 0)) {
+ # repeat 4 byte mask to payload length + up to 4 byte
+ $mask = $mask x (int($payload_len / 4) + 1);
+ # truncate mask to payload length
+ substr($mask, $payload_len) = "";
+ # (un-)apply mask
+ $payload ^= $mask;
}
$payload = decode_base64($payload) if !$binary;