I've finally gotten to the stage of getting a response from a UDP tracker.
Here's an exmaple, that I split into an array:
[ 1, 3765366842, 1908, 0, 2, 0 ]
Action, request ID, interval, leechers, seeders, peers.
No matter which torrent I chose, I get 1/2 seeders, which I'm assuming is the server tracking me, and no peers / leechers.
Am I not using the correct info hash?
This is how I retrieve it from a magnet link:
magnet:?xt=urn:btih:9f9165d9a281a9b8e782cd5176bbcc8256fd1871&dn=Ubuntu+16.04.1+LTS+Desktop+64-bit&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Fzer0day.ch%3A1337&tr=udp%3A%2F%2Fopen.demonii.com%3A1337&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Fexodus.desync.com%3A6969
...
h = 9f9165d9a281a9b8e782cd5176bbcc8256fd1871
Now I split this into chunks of two, and parse them, for hex bytes:
bytes = [];
for (var i = 0; i < h.length; i++) bytes.push(parseInt((h[i]) + h[i++], 16));
[153, 153, 102, 221, 170, 136, 170, 187, 238, 136, 204, 85, 119, 187, 204, 136, 85, 255, 17, 119]
There's no need to encode this, so I send it along with my request.
This is the only point causing trouble, yet it seems so simple...
As the8472 says, your decoding is incorrect:
for (var i = 0; i < h.length; i++) bytes.push(parseInt((h[i]) + h[i++], 16));
i and i++ will have the same value here. (One of the reasons to avoid clever inline stuff.) You can use i and ++i, or maybe expand it all to multiple lines for readability:
for (var i = 0; i < h.length; i += 2) {
var hex = h.substr(i, 2);
bytes.push(parseInt(hex, 16));
}
And if you’re using Node, just parse it into a Buffer, which can easily be converted to an array if necessary:
var bytes = Buffer.from(h, 'hex');