Is it possible to use UdpClient through an anonymous proxy? - vb.net

I am sending a big endian byte array to a UDP host and all works well, but I need to incorporate proxies into the mix.
From what I've found (or haven't found) there is no straight forward way to use anonymous proxies (or even Socks4/5) with UdpClient. Can anyone help?

You should use System.Net.HttpWebRequest.Proxy for the proxy. Check the MSDN code snippet link for more information. I had a similar problem and this helped.

Related

How to discover other domain hosts using rtps_discovery

Recently, I try hard to use OpenDDS SSL in WAN network. But All my attempts to failed.
This is caused by the inability to find different hosts.
I realized one thing. OpenDDS security should use rtps_discovery, not InfoRepo, and it is difficult to find two hosts in different subnetworks via rtps_discovery.
I have been searched about discovering host by rtps_discovery option from SourceForge, github, and stackoverflow. But, No one successed in this manner.
https://sourceforge.net/p/opendds/mailman/message/36320180/
https://github.com/objectcomputing/OpenDDS/issues/854
So, my question is how to find the host using rtps_discovery on the WAN network.
here is my ini file:
[common]
DCPSGlobalTransportConfig=$file
DCPSSecurity=1
[domain/4]
DiscoveryConfig=uni_rtps
[rtps_discovery/uni_rtps]
SedpMulticast=0
ResendPeriod=2
SpdpSendAddrs=publisher's IP:56789
[transport/the_rtps_transport]
transport_type=rtps_udp
use_multicast=0
local_address=subscriber's IP:55555
please give me some ideas to solve this problem
It is really impossible to discover hosts in different subnetworks via rtps_discovery??
I'm finally success to communicate using rtps discovery!
It just SpdpSendAddrs attribute set 8410 port.
like this:
[common]
DCPSGlobalTransportConfig=$file
DCPSSecurity=1
[domain/4]
DiscoveryConfig=uni_rtps
[rtps_discovery/uni_rtps]
SedpMulticast=0
ResendPeriod=2
SpdpSendAddrs=subscriber's IP:8410
[transport/the_rtps_transport]
transport_type=rtps_udp
use_multicast=0
But, new question is that how to confirm this security function work properly??
When I capture packet by wireshrk, I can see the data not encryped.
I used OpenDDS Messenger security example.

HTTPS proxy with support for chunked-encoded requests

I'm developing a simple HTTPS proxy (written in Python) which receives POST/GET requests/responses, applies some transformation and finally forwards the result to the recipient.
I need to handle chunked-encoded requests/responses in a "streaming" fashion, meaning that as soon as a chunk is received the proxy transforms it and forwards it to the recipient.
Before deciding to support chunked-encoded requests, I've been using mitmproxy http://mitmproxy.org/ and it worked perfectly. Unfortunately, I noticed that it waits until the entire body is received before letting me handle the response/request.
How can I implement a proxy supporting chunked-encoded requests/responses? Has anyone of you ever done something like this?
Thanks
EDIT: MORE INFO ON MY USE CASE
I need to handle POST requests and GET responses.
In the POST request I receive a JSON object and I have to encrypt some of its values.
In the GET response I receive a JSON object and I have to decrypt some of its values.
Till now, the following code has worked perfectly:
def handle_request(self, r):
if(r.method=='POST'):
// encryption of r.get_form_urlencoded()
def handle_response(self, r):
if(r.request.method=='GET'):
// decryption of r.content
How can I do the same thing with single chunks?
EDIT: UPDATES
After evaluating different solutions, I decided to go for Squid (proxy) + ICAP (content adaptation).
I've successfully configured Squid and the performance are just great. Unfortunately, I can't find a suitable ICAP server (in Python, if possible) for doing content adaptation (modification). I thought this one https://github.com/netom/pyicap could do the job but looks like it doesn't read the body of myPOST requests.
Do you guys know a Python ICAP server that I can use together with Squid?
Thanks
The answer below is outdated. You can now pass --stream to mitmproxy, whose behaviour is explained in the mitmproxy documentation.
mitmproxy developer here. This is definitely a feature we want for mitmproxy as well, but it's not that trivial and probably not coming very soon. If you really want to implement that yourself, I can recommend two things:
If you have a very specific use case, you can employ libmproxy.protocol.http.HTTPRequest.from_stream for parsing the header and do the body processing yourself.
If you do not want to modify the request/response body, you may find it sufficient to modify mitmproxy itself. In a nutshell, you would need to read the request/response without content (see 1.), modify it to your needs, pass it to the server and then delegate control to the libmproxy.protocol.tcp (see https://github.com/mitmproxy/mitmproxy/blob/master/libmproxy/proxy/server.py#L169)
If you have further questions, don't hesistate to ask here or on mitmproxy's IRC channel.
Re Comment #1:
You can't take too much out of mitmproxy, but at least you get delegate the header parsing & processing.
# ...accept request, socket.makefile() etc...
req = HTTPRequest.from_stream(client_conn.rfile, include_content=False)
# manually forward to the server (req._assemble_head())
# manually receive response body chunk by chunk and forward it to the server, see
# https://github.com/mitmproxy/netlib/blob/master/netlib/http.py#L98
resp = HTTPResponse.from_stream(server_conn.rfile, include_content=False)
# manually forward headers
# manually process body and forward
That being said, this is a fairly complex topic. Eventually, you're better off hacking that directly into libmproxy.protocol.http.HTTPHandler.
Another option, depending on your use case again: Use mitmproxy, set the conntype to tcp and forward traffic as-is and use regex replacements on the content in libmproxy.protocol.tcp . Probably the easiest way, but the most hacky one.
If you can provide some context, I may guide you further in the right direction.
Re Comment #2:
Before we get to the main part: JSON is a really bad choice for streaming/chunking as long as you don't want to encrypt the complete JSON object and treat it as a single string. You should definitely consider something like tnetstrings if you only want to encrypt parts.
Apart from that, hooking into read_chunk works, but first you need to get to the point where you can actually receive chunks over the line. Then, it's as simple as reading the single chunks, encrypting them and forwarding them.

Sending a file from a java client to a server using wcf method?

I want to build a wcf web service so that the client and the server would be able to transfer files between each other. Do you know how I can achieve this? I think I should turn it into a byte array but I have no idea how to do that. The file is also quite big so I must turn on streamed response.
It sounds like you're on the right track. A quick search of the interwebz yielded this link: http://www.codeproject.com/Articles/166763/WCF-Streaming-Upload-Download-Files-Over-HTTP
Your question indicates that you want to send a file from a java client to a WCFd endpoint, but the contents of your question indicate that this should be a bidirectional capability. If this is the case, then you'll need to implement a service endpoint on your client as well. As far as that is concerned, I cannot be of much help, but there are resources out there like this SO question: In-process SOAP service server for Java
As far as practical implementation, I would think that using these two links you should be able to produce some code for your server and client.
As far as reading all bytes of a file, in C# you can use: File.ReadAllBytes It should work as in the following code:
//Read The contents of the file indicated
string fileName = "/path/to/some/file";
//store the binary in a byte array
byte[] buffer = File.ReadAllBytes(fileName);
//do something with those bytes!
Be sure to use the search function in the future:

xbuf_frurl does not work properly without server header of content length?

I try to get some info from other sites with xbuf_frurl.
I got some site OK but some Not OK.
By Now, I still can not make sure what is going wrong.
But some sites are missing the content length header.
Who can tell whether xbuf_frurl() relies on the (potentially missing) content length header, esp. when growing the buffer?
xbuf_frurl() is indeed reading a body IF an HTTP content-length header is present. It will not try to decode chunked responses.
To deal with those servers using chunked replies, use the G-WAN curl.c example provided with the distribution. With libcurl you have even the opportunity to use SSL/TLS.
If that's not resolving your problem, the only way to troubleshoot this kind of issues is to give a non-working example, with both the full request that you have sent and the full reply received from the server.
That's why the xbuf_xcat("%v") format has been added: to give hexdumps, even with binary replies.
Edit your question and add this information to let people help you with a well-defined problem.

BizTalk Dynamic WCF-WSHttp Send Port reverting to Http Adapter

I'm trying to send a message to the WCF-WSHttp adapter with a dynamic
send port from an orchestration, but BizTalk seems to always be
reverting back to the HTTP Adapter.
According to the docs that I've been able to find, I should just need
to set the transport type from my expression shape to get BizTalk to
use the WCF-WSHttp adapter, and I AM, but it still seems to be
reverting. Below is an example of my expression shape that's setting
the properties (as you can see, I've tried both
Microsoft.XLANGs.BaseTypes.TransportType and
BTS.OutboundTransportType):
Body(BTS.OutboundTransportType) = "WCF-WSHttp";
SendMessagePort(Microsoft.XLANGs.BaseTypes.Address) =
System.String.Format("{0}/Accept{1}", "http://myserver/myservice/
myservice.svc/Accept{0}", messageInfo.MessageType);
SendMessagePort(Microsoft.XLANGs.BaseTypes.TransportType) = "WCF-
WSHttp";
Probably are Craig :-)
When using a dynamic send port, BizTalk uses the "scheme" part of the url to decide which adapter to use.
When your url starts with "Http://" or "Https://" BizTalk would always use the HTTP adapter.
Similarly url's begining with ftp:// will use the FTP adapter.
Same works for custom adapaters as well - when you install the adapter's configuration you register the moniker to use; for example - the open source Scheduled Task adapter uses schedule:// (I believe).
Using dynamic send ports with WCF is slightly more involved than most other adapaters because of the various configuration that's required but you can find detailed explanation here, just scroll down to the "Dynamic Send Ports" section about half way down.
I ended up resolving my issue, but am still unsure of the reasoning for the behavior I saw.
The Expression shape mentioned in the question was located inside of an Atomic Scope. Once the Orchestration exited the scope containing the Expression shape, the Transport Type was reset back to its original value. Moving the Expression out of the atomic scope resolved the issue, in that the TransportType was set correctly.