HTTP request with wrong infoHash

[tnako]

Hello. I have torrent file - https://github.com/tnako/DP/blob/master/my/liferace.torrent
That data cannot be downloaded. It cooked for local XBT.

If I started webtorrent, it send wrong infoHash to tracker server. For example, I use your cmd.js:

DEBUG=* node cmd.js liferace.torrent 2>&1 | grep a2a1553754

It will give right infoHash:

Mon, 01 Dec 2014 15:18:45 GMT bittorrent-swarm new swarm i a2a15537542b22925ad10486bf7a8b2a9c42f0d1 p 2d5757303030312d386238633332336161343163
Mon, 01 Dec 2014 15:18:45 GMT torrent-discovery setTorrent a2a15537542b22925ad10486bf7a8b2a9c42f0d1
Mon, 01 Dec 2014 15:18:45 GMT bittorrent-tracker new client a2a15537542b22925ad10486bf7a8b2a9c42f0d1

But the same time tcpdump -s 0 -A port 2710 give me:

.i.7....GET /announce?info_hash=%a2%a1U7T%2b%22%92Z%d1%04%86%bfz%8b*%9cB%f0%d1&peer_id=-qB31A0-!I_EUqrSvcsd&port=6881&uploaded=0&downloaded=0&left=1091506387&corrupt=0&redundant=0&compact=1&numwant=0&key=c60fff68&no_peer_id=1&supportcrypto=1&event=stopped&ip=...

With this info_hash i go to http://url-encode.online-domain-tools.com/ and make url decode, in hex it will be:

a2  a1  55  37  54  20  22  92  5a  d1  04  86  bf  7a  8b  2a    9c    42  f0  d1   

The error after a2a1553754, it must be 0x2b, not 0x20

---

Versions:

webtorrent@0.16.0 node_modules/webtorrent                                                                                                                                                                                                                                      
├── thunky@0.1.0                                                                                                                                                                                                                                                               
├── speedometer@0.1.3                                                                                                                                                                                                                                                          
├── network-address@0.0.5                                                                                                                                                                                                                                                      
├── clivas@0.1.4                                                                                                                                                                                                                                                               
├── http-https@1.0.0                                                                                                                                                                                                                                                           
├── git-sha1@0.1.2                                                                                                                                                                                                                                                             
├── range-parser@1.0.2                                                                                                                                                                                                                                                         
├── inherits@2.0.1                                                                                                                                                                                                                                                             
├── end-of-stream@1.1.0
├── bitfield@1.0.2
├── pump@1.0.0
├── extend.js@0.0.1
├── hat@0.0.3
├── addr-to-ip-port@1.4.0
├── prettysize@0.0.3
├── random-access-file@0.3.1
├── re-emitter@1.0.0
├── rimraf@2.2.8
├── run-parallel@1.0.0
├── multistream@1.4.2
├── block-stream@0.0.7
├── mime@1.2.11
├── minimist@1.1.0
├── windows-no-runnable@0.0.6
├── moment@2.8.4
├── mkdirp@0.5.0 (minimist@0.0.8)
├── once@1.3.1 (wrappy@1.0.1)
├── filestream@2.1.1 (typedarray-to-buffer@1.0.4)
├── nodebmc@0.0.5 (mdns-js@0.1.0)
├── dezalgo@1.0.1 (wrappy@1.0.1, asap@1.0.0)
├── debug@2.1.0 (ms@0.6.2)
├── ut_metadata@2.6.0 (bencode@0.6.0)
├── webtorrent-swarm@0.3.3 (bittorrent-protocol@1.4.2)
├── bittorrent-swarm@0.16.4 (bittorrent-protocol@1.4.2)
├── concat-stream@1.4.7 (typedarray@0.0.6, readable-stream@1.1.13)
├── bittorrent-dht@2.6.4 (compact2string@1.3.0, buffer-equal@0.0.1, k-bucket@0.4.2, bencode@0.6.0, is-ip@1.0.0, string2compact@1.2.0)
├── load-ip-set@1.0.5 (split@0.3.2, ip-set@1.0.0)
├── ut_pex@1.0.1 (compact2string@1.3.0, bencode@0.6.0, string2compact@1.2.0)
├── airplay-js@0.2.6 (plist-with-patches@0.5.1, mdns-js@0.2.2)
├── torrent-discovery@2.0.4 (bittorrent-tracker@2.9.1, webtorrent-tracker@0.5.0)
└── chromecast-js@0.1.4 (debug@1.0.4, mdns-js2@0.0.5, castv2-client@0.0.4)

[feross]

What version of webtorrent are you using? Please run webtorrent --version and report back here. Several tracker bugs were fixed a few versions back.

[tnako]

Fresh install of webtorrent have the same issue:

$ node cmd.js --version
0.16.0

Added versions to the main post

[feross]

@tnako When I looked at the output from your tcpdump and decode the info_hash, which is shown as:

%a2%a1U7T**%2b**%22%92Z%d1%04%86%bfz%8b*%9cB%f0%d1

I get:

a2 a1 55 37 54 2b 22 92 5a d1 04 86 bf 7a 8b 2a 9c 42 f0 d1

Which is correct! This means the correct http request is being made to the tracker server. I also confirmed that the correct request is made using a different tracker server (since the one in this torrent is down).

It seems to me like %2b (which decodes to a + character) is likely being converted into %20 by the http server. What tracker software is running at http://lr1.gamingboom.ru:2710/?

[feross]

Could there be a proxy server (like Apache or Nginx) in front of the tracker that is incorrectly converting %2b into a space character?

[feross]

This is interesting. On my local machine, the info_hash was actually:

%a2%a1U7T+%22%92Z%d1%04%86%bfz%8b*%9cB%f0%d1

Note: the unescaped + and * characters. These should definitely be escaped, but aren't. This could definitely cause the bug you saw, and it shouldn't be happening.

PR out to bittorrent-tracker to fix this: webtorrent/bittorrent-tracker#52

[feross]

I believe this issue is fixed now. Released as 0.17.0.