Scapy中的HTTP GET数据包嗅探器

Question

我试图在Scapy中编写一个简单的嗅探器,它只使用GET方法打印HTTP数据包.这是代码:

#!/usr/bin/python
from scapy.all import *

def http_header(packet):
        http_packet=str(packet)
        if http_packet.find('GET'):
                print GET_print(packet)
        print packet
def GET_print(packet1):
        print "***************************************GET PACKET****************************************************"
        print packet1

        print "*****************************************************************************************************"


sniff(iface='eth0',prn=http_header)

这是输出:

*****************************************************************************************************
None
T???
     )?pEa??@@???h??#/??t
                             ?}LGku???U
oTE??I(????9qi???S?????
                          XuW?F=???-?k=X:?
***************************************GET PACKET****************************************************
T???
     )?pE???@@???h??#/??t
                               ?LGku????
oTE??I?K??AH?*?e??>?v1#D?(mG5T?o????8?????????"?KT^?'?mB???]?????k>
                                                                                ?_x?X?????8V???w/?Z?=???N?À??\r?????)+}???l?c?9??j;???h??5?T?9H?/O??)??P
         ?Y?qf??%?_`??6x??5D?I3???O?
t??tpI#?????$IC??E??
                     ?G?
J??????=?]??v????b5^|P??DK?)uq?2????w?
                    tB??????y=???n?i?r?.D6?kI?a???6iC???c'??0dPqED?4????[?[??hGh???~|Y/?>`\6yP  Dq??T??M????f?;???????  gY???di?_x?8|
eo?p?xW9??=???v?Ye?}?T???y?^?C
-?_(?<?{????}???????r
$??J?k-?9????}??f?27??QK??`?GY?8??Sh???Y@8?E9?R??&a?/vk???6?DF`?/9?I?d( ??-??[A
                                                                                     ??)pP??y\?j]???8?_???vf?b????I7???????+?P<_`
*****************************************************************************************************

我期待的是:

GET / HTTP/1.1
    Host: google.com
    User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20140722 Firefox/24.0 Iceweasel/24.7.0
    Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
    Accept-Language: en-US,en;q=0.5
    Accept-Encoding: gzip, deflate
    Cookie: PREF=ID=758a20b5fbd4eac9:U=2b2dedf6c84b001f:FF=0:TM=1412150291:LM=1415430021:S=Q-QemmrLqsSsEA9i; NID=67=mRdkPVhtImrOTLi5I1e5JM22J7g26jAcdiDEjj9C5q0H5jj0DWRX27hCM7gLJBeiowW-8omSv-1ycH595SW2InWX2n1JMMNh6b6ZrRsZ9zOCC2a-vstOQnBDSJu6K9LO
    Connection: keep-alive

我该怎么做才能获得预期的产量？

Answer 1

您需要使用数据包的sprintf功能而不是打印数据包本身.您还需要拆分从它返回的字符串并将其与换行符一起连接在一起,否则它会在一行中将其全部吐出:

#!/usr/bin/python
from scapy.all import *

def http_header(packet):
        http_packet=str(packet)
        if http_packet.find('GET'):
                return GET_print(packet)

def GET_print(packet1):
    ret = "***************************************GET PACKET****************************************************\n"
    ret += "\n".join(packet1.sprintf("{Raw:%Raw.load%}\n").split(r"\r\n"))
    ret += "*****************************************************************************************************\n"
    return ret

sniff(iface='eth0', prn=http_header, filter="tcp port 80")

我还为TCP端口80添加了一个过滤器,但如果需要,可以将其删除.

示例输出:

***************************************GET PACKET****************************************************
'GET /projects/scapy/doc/usage.html HTTP/1.1
Host: www.secdev.org
Connection: keep-alive
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.65 Safari/537.36
Referer: https://www.google.co.uk/
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-GB,en;q=0.8,en-US;q=0.6
If-None-Match: "28c84-48498d5654df67640-gzip"
If-Modified-Since: Mon, 19 Apr 2010 15:44:17 GMT

'
*****************************************************************************************************

皮埃尔指出,你可以http_header通过使用lfilter参数完全取消函数sniff().我冒昧地在同一时间使代码更简洁:

#!/usr/bin/python
from scapy.all import *

stars = lambda n: "*" * n

def GET_print(packet):
    return "\n".join((
        stars(40) + "GET PACKET" + stars(40),
        "\n".join(packet.sprintf("{Raw:%Raw.load%}").split(r"\r\n")),
        stars(90)))

sniff(
    iface='eth0',
    prn=GET_print,
    lfilter=lambda p: "GET" in str(p),
    filter="tcp port 80")