Problems with REST HTTPS request on WinCE

Question

I'm porting a vb.net HTTPS client application on WinCE60 CF35: bsically it needs to send HTTPS REST requests to a server.

I started development on a Win10 desktop and there I have no problems (VS2015 - NET35).

When I run on WinCE I receive an exception when I send the webrequest: the system says that it does not have the error message, but I see the status = 10 = SecureChannelFailure.

The code is the following:

Private Function SendGetRequest(cmd As String) As Boolean

    Dim request As WebRequest = WebRequest.Create(m_baseUrl + cmd)

    request.Method = "GET"
    request.Timeout = m_timeout
    request.Headers.Add("Authorization", "Basic " + m_authInfo)
    '
    Dim dataStream As Stream
    '
    Try
        Dim response As WebResponse = request.GetResponse()
        m_statusCode = CType(response, HttpWebResponse).StatusCode

        dataStream = response.GetResponseStream()
        ...

On the server side I don't receive anything. So, I tryed to sniff using Wireshark and I see the following:

In my understanding the client (.113) sends a RESET, but I don't know why ..

PS: if I build a HTTP request I receive response.

I substituted the standard calls with the ones by Rebex. This library can generate a log where I found: 2017-07-14 16:27:44 INFO HttpRequest(1)[89589158] TLS: Certificate verification status: RootNotTrusted, CnNotMatch (32) — SteMMo, Jul 14 '17 at 16:57
For the moment I solved with the Rebex lib adding to my source code the line: client.Settings.SslAcceptAllCertificates = True Now I'd like to understand if the problem on CF35 was on TLS version, SHA version or whatever .. — SteMMo, Jul 18 '17 at 10:09

score 1 · Answer 1 · answered Jul 16 '17 at 05:30

Multiple potential issues here:

Based on the error message, the most likely problem: The CE device may be missing a root certificate, or the root certificate may be expired or revoked, and therefore Windows CE is unable to verify the server certificate. If your CE device has a UI, open the Certificates applet in the Control Panel to verify that the required root certificate is installed and valid
.NET CF does not support SHA-2 based certificates (see answers here). Mentioning this because it's the next problem you are likely to run into, once the root cert is in place
Windows CE often sends RST to close TCP connections. Not pretty, but probably unrelated to the HTTPS problem you're seeing (as far as I understand the rationale is this is faster than having both sides send FIN/ACK)

Problems with REST HTTPS request on WinCE

1 Answers1