$msg = "this is a test messagez";
$key = "\x4f\xcb"; # or $key = pack "n", 0x4fcb;
$xored = $msg ^ $key;
print join(" ", split(//, $msg)), "\n";
print join(" ", unpack("(H2)*", $msg)), "\n";
print join(" ", unpack("(H2)*", $key)), "\n";
print join(" ", unpack("(H2)*", $xored)), "\n";
__END__
t h i s i s a t e s t m e s s a g e z
74 68 69 73 20 69 73 20 61 20 74 65 73 74 20 6d 65 73 73 61 67 65 7a
4f cb
3b a3 69 73 20 69 73 20 61 20 74 65 73 74 20 6d 65 73 73 61 67 65 7a
####
$key = "\x4f\xcb" x (length($msg)/2);
or
$key = pack("n", 0x4fcb) x (length($msg)/2);
##
##
t h i s i s a t e s t m e s s a g e z
74 68 69 73 20 69 73 20 61 20 74 65 73 74 20 6d 65 73 73 61 67 65 7a $msg
4f cb 4f cb 4f cb 4f cb 4f cb 4f cb 4f cb 4f cb 4f cb 4f cb 4f cb $key
3b a3 26 b8 6f a2 3c eb 2e eb 3b ae 3c bf 6f a6 2a b8 3c aa 28 ae 7a XOR result