[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
[tor-bugs] #11648 [Tor]: Problem parsing .z-compressed descriptors fetched via DirPort
#11648: Problem parsing .z-compressed descriptors fetched via DirPort
-----------------------+---------------------
Reporter: karsten | Owner:
Type: defect | Status: new
Priority: normal | Milestone:
Component: Tor | Version:
Keywords: tor-relay | Actual Points:
Parent ID: | Points:
-----------------------+---------------------
I'm having trouble parsing compressed descriptors fetched via tor's
DirPort. I don't know enough about .z compression to track down the
problem though. Anyway, here's what I found:
Download consensus and all server descriptors from turtles:
{{{
curl http://76.73.17.194:9030/tor/status-vote/current/consensus.z >
turtles-consensus.z
curl http://76.73.17.194:9030/tor/server/all.z > turtles-server-all.z
}}}
Attempt to parse compressed consensus using Python's zlib:
{{{
Python 2.7.5 (default, Aug 25 2013, 00:04:04)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import zlib
>>> print len(zlib.decompress(open('turtles-consensus.z', 'rb').read()))
1085611
>>> print len(zlib.decompress(open('turtles-server-all.z', 'rb').read()))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
zlib.error: Error -5 while decompressing data: incomplete or truncated
stream
>>> print len(zlib.decompressobj().decompress(open('turtles-server-all.z',
'rb').read()))
8932838
}}}
Decompressing the consensus works fine using `zlib.decompress()`, but
decompressing the server descriptors does not. The only workaround I
found was to explicitly create a decompressor using
`zlib.decompressobj()`. AIUI, the difference between the two approaches
is that the latter can handle partial content (cf.
http://stackoverflow.com/questions/20620374/how-to-inflate-a-partial-zlib-
file/20625078#20625078).
Does that mean tor sends partial content?
Cc'ing atagar and wfn, because we discussed this problem a year ago:
https://lists.torproject.org/pipermail/tor-dev/2013-May/004924.html
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/11648>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online
_______________________________________________
tor-bugs mailing list
tor-bugs@xxxxxxxxxxxxxxxxxxxx
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs