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Analyzing HTTP streams
This article will
introduce you to various techniques for analyzing
HTTP streams.
Unsniff has powerful analysis capabilities for HTTP analysis including.
* Extract content (user objects) from
HTTP streams
* View entire HTML pages, images, flash,
and media from within Unsniff
* View all HTTP headers
* View color-coded HTTP requests and
responses
* Full web pages including inline
images, flash, stylesheets supported
* Click through to other captured pages
* Save pages for later analysis
* Scripts to extract interesting data
from HTTP headers
The
reconstruction capabilities are so powerful that several of
our customers are using Unsniff as an offline
“recording” tool.
Viewing HTTP headers
From the “Packets” sheet click on any HTTP packet (except those labeled
“Data continued..”).

View all HTTP headers as columns in a list
This is useful if you want to analyze all HTTP headers as a group.
Right click on any HTTP packet and select “Protocol
View” from the popup menu.
The protocol details view shows all the HTTP header fields in a single
list. You can select any item from the list to see the packet details
in the pane below.

View entire HTTP stream
You can analyze entire HTTP sessions using the stream analysis
capabilities of Unsniff. You can watch HTTP pipelining in action as
well as TCP behavior including usage of RST and Keep-Alive.You can
switch to the Streams sheet and watch all HTTP sessions in
real-time, you can see requests and responses as they appear.
There are two ways to view a HTTP stream.
- Bottom up – Like older network analyzers, you can
select a HTTP packet – then right click and select
“Locate Flow” from the popup menu. This takes you
to the stream and the corresponding segment in that stream.
- Top down – Unsniff features full stream analysis.
You can simply choose the stream you are interested in from a list. You
can then work your way down to link layer packets if you desire. You
will find yourself using Top Down analysis more frequently as you
become familiar with Unsniff
Either way you can see the entire stream as shown in the figure below,
you can click on the ‘+’ icon next to each stream
to show the individual segments that make up the stream.

View request response data
You can also view color-coded request/response data for the stream.
Simply select the stream, right click and select “Show
Data”. This shows the data in hex with blue for outgoing
bytes and green for incoming data bytes. If you want to see an ASCII
representation, simply right click on the data and select
“UTF-8 with line breaks”

Save payload
You can save all incoming and outgoing data of the HTTP session. Simply
right click on the stream and select “Reassemble and
Save” from the popup menu.
View User objects (HTML pages, images, flash and other
content)
User Objects is a cool new concept introduced by Unsniff. It represents
any entity which is of interest to the user. When you are analysing
HTTP you are probably interested in the actual HTML served, the
stylesheet used, the quality of images served, even the google ads that
were served up. All these entities are called “User
Objects”. Unsniff will attempt to extract these user
objects from the HTTP stream. The extracted user objects are
then shown in the User Objects sheet.
Enable full HTML page
reconstruction
To view entire HTML pages using only the content in the capture file,
you must set the " Reconstruct
HTTP streams" option from the Plugins->Customize
menu.
To see HTML pages:
Switch to the user objects sheet

You can then select any user object from the list. The selected user
object will the rendered in the space below the list. You can also
float the user object in a separate window by right click
“Open in New Window”.
If you select a HTML page from the list, Unsniff will reconstruct the
entire page. You can see how the page looked exactly – you
can even click through to other viewed content such as other HTML
pages, video, flash games, etc.

Conclusion
You have seen how Unsniffs top-down analysis combined with the
powerful concept of user objects help you to analyze HTTP like never
before. Experiment with these new tools. You can even try your hand at
writing simple scripts to perform your own analysis.
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