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.netproxynetwork-programmingwebrequestclient-certificates

unable to post a https WebRequest in .net?

Hi i am encountering problems trying to post a WebRequest under Https.

i received the following errors

1.-The underlying connection was closed: Unable to connect to the remote server.

2.-the operation TimeOut

3-The underlying connection was closed: Could not establish secure channel for SSL/TLS.

i tried with about 3 or 4 different proxies of my company and the customer company and not even when i am directly with the ISP provider with no restrictions, i get the above errors when executing the following method

WebRequest.GetRequestStream()

this occurs behind a proxy or not, the request can only be succesfully post from one single PC which is behind a proxy. the proxy doesn't have a client certificate installed.

this is under .net framework 1.1 and the request already contains network credentials.

what could be?

Update

the inner exception the 3rd error is the following: The function completed successfully, but must be called again to complete the context

according to iisper.h documentation this error belongs to the 

//
// MessageId: SEC_I_CONTINUE_NEEDED
//
// MessageText:
//
//  The function completed successfully, but must be called
//  again to complete the context
//
#define SEC_I_CONTINUE_NEEDED            ((HRESULT)0x00090312L)

on MSDN this refers to

SEC_I_CONTINUE_NEEDED The client must send the output token to the server and wait for a return token. The returned token is then passed in another call to InitializeSecurityContext (Schannel). The output token can be empty.

does this means the PC lacks a client certificate?

Solution

  • There are a whole number of things that could be complicating things, as far as inconsistencies with the SSL certs, etc. But first, you should do some basic debugging to rule out the obvious things:

    -- Did you try sending a simple web request to other servers? Try both (unsecured) http and (secured) https

    -- Did you try connecting from another computer, or from another network? You mentioned that the client is behind a proxy; try a computer w/o a proxy first, to rule that out.

    -- Are you making multiple WebRequests within the session? There is a hard-limit on the number of open requests, so make sure you're closing them after you get the WebResponse. Perhaps make a test program with just one request.

    If that doesn't narrow it down, then it's probably something more complicated, with their the server or the proxy. You can track outgoing network packets with a program such as netshark to try to track down where things are getting stuck.