How to convert torrent info hash for scrape?

Question

I have a torrent hash from the magnet link. For example: fda164e7af470f83ea699a529845a9353cc26576 When I try to get information about leechers and peers I should request: http://tracker.publicbt.com/scrape?info_hash=??? How should I convert info hash for this request? Is it url encoding or becoding? how? In PHP.

Answer 1

It's a raw hexadecimal representation. Use pack() with H to convert it. Then URL encode it.

Answer 2

The info_hash is always url-safe, you need not encode or escape it in any way. It is actually an md5 of the torrent file's header.

Answer 3

Got this python snippet from a colleague,

r = ''
s = 'fda164e7af470f83ea699a529845a9353cc26576'
for n in range(0, len(s), 2):
    r += '%%%s' % s[n:n+2].upper()
print r

Output: %FD%A1%64%E7%AF%47%0F%83%EA%69%9A%52%98%45%A9%35%3C%C2%65%76

Works like a charm.

Edit: Works like a charm for getting the tracker to give back status 200 (ok) but still doesn't work for retrieving the torrent details...