[Oisf-devel] libhtp 0.5.x integration - bug 775

[Brian Rectanus]

On Mon, Apr 8, 2013 at 9:16 AM, Brian Rectanus <brectanu at gmail.com> wrote:

>
> On Mon, Apr 8, 2013 at 8:47 AM, Anoop Saldanha <anoopsaldanha at gmail.com>wrote:
>
>> On Mon, Apr 8, 2013 at 3:42 PM, Victor Julien <victor at inliniac.net>
>> wrote:
>> > (moving to oisf-devel)
>> >
>> > On 04/08/2013 06:17 AM, Anoop Saldanha wrote:
>> >>>> I recollect we introduced path and query double decoding through
>> >>>> configurable params, and also we had this thing with query
>> >>>> decoding(single level).  Can you explain a bit what the status was
>> >>>> previously.  Seeing related failed uts.
>> >>>>
>> >>>
>> >>> We run the path normalization on the query through our
>> >>> HTPCallbackRequestUriNormalizeQuery callback. Previously we used
>> >>> htp_decode_path_inplace to normalize the query (e.g. for uridecoding).
>> >>> However, this was causing issues (remember that pcre "bug" we
>> discussed
>> >>> a while back, where http:// turned into http:/).
>> >>>
>> >>> In libhtp I copied htp_decode_path_inplace to htp_decode_query_inplace
>> >>> and also copied the config params and cfg funcs:
>> >>>
>> https://github.com/inliniac/suricata/commit/d41c762689a08e6814dc93e8bfebeceab97175c3
>> >>>
>> >>> Hack of the 1st order, which is wrong in many ways. But it basically
>> >>> allowed me to make sure we don't normalize the query as if it's path,
>> >>> esp with turning ftp:// into ftp:/ and such.
>> >>>
>> >>> For 0.5 integration I think we need a proper solution. The only
>> reason I
>> >>> pushed my hack like this was that I knew in 0.5 we would make things
>> right.
>> >>>
>> >>
>> >> I think if we still want to double decode, we still require all of
>> >> these above things from our bundled htp.
>> >>
>> >> -----
>> >>
>> >> In 0.5.x, tx->request_uri_normalized has been removed, and we'd now
>> >> have to use the REQUEST_URI hook.  We'll have to carry out the
>> >> reconstruction ourselves, and store it ourselves in our HTPState.
>> >>
>>
>> What are your thoughts on this?
>>
>> >
>> > IIRC there is some function in libhtp that does just the decoding of
>> > uriencoding and unicode. We should probably just use that on the query
>> > and do the full normalization on the path.
>> >
>> > As a side thought: I think it would be nice to store path and query
>> > separately so that we can add http_path and http_query keywords later
>> on.
>> >
>>
>> We'd pretty much extract it directly from parsed_uri.  Will have to
>> check if we need the extract double decode phase we have currently in
>> our bundled htp, in which case we'd need to store them separately.
>>
>>
> Yes, all the normalized components are in tx->parsed_uri.  This is what is
> used in ironbee to expose all the various parts like tx->parsed_uri->path
> and tx->parsed_uri->query.
>
> Also note that the hostname should now be obtained
> from tx->request_hostname in 0.5.
>
> -B
>

FYI, for an example using libhtp 0.5 see ironbee code.  This was all
recently updated for 0.5.

https://github.com/ironbee/ironbee/blob/0.7.x/modules/modhtp.c

-B
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