I am trying to forward a network packet formed by scapy to the rest service, but somehow packet gets corrupted at receiver side (rest service side).
I formed the network packet using scapy:
0000 1a 0b 0c 14 05 16 00 00 00 00 00 00 08 00 45 00 ..............E.
0010 01 10 00 01 00 00 40 11 f0 d2 05 05 05 04 7f 00 ......@.........
0020 00 01 00 44 00 43 00 fc 85 7f 01 00 00 00 00 00 ...D.C..........
0030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0080 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0100 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0110 00 00 00 00 00 00 63 82 53 63 35 01 01 ff ......c.Sc5...
I forwarded the captured scapy packet to web service using python code :
h = httplib2.Http(".cache")
h.add_credentials("user","passworkd")
data = urllib.urlencode({"packet":pack})
resp, content = h.request(url, "POST", data, headers={'Content-Type': 'applicatoin/x-www-form-urlencodede'})
At the server side(implemented in java) I printed the obtained packet(byte stream) it shows the following output (which is different from the send packet) :
1a0b0c140516000000000000080045000110000100004011efbfbdefbfbd050505047f0000010044004300efbfbd7f010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000063efbfbd5363350101efbfbd
Edit:
Java server side handling :
@Path("/test")
@POST
@StatusCodes({
@ResponseCode(code = 200, condition = "Destination reachable"),
@ResponseCode(code = 503, condition = "Internal error"),
@ResponseCode(code = 503, condition = "Destination unreachable") })
public Response rcvDHCPPkt(@FormParam("packet") String packet) {
String pkt_decode = URLDecoder.decode(packet, "UTF-8"); // tried with and without it.
// here it shows the packet corruption. I tried to print packet also it has same problem.
System.out.println("packet received:" + byteArrayToHex(packet_decode.getBytes()));
used following function to print the hex equivalent.
public static String byteArrayToHex(byte[] a) {
StringBuilder sb = new StringBuilder(a.length * 2);
for(byte b: a)
sb.append(String.format("%02x", b & 0xff));
return sb.toString();
}
Please suggest me, if I am missing something. I am suspecting two problem urlencoding or networks byte ordering.
