HTTPS on Compact Framework

[Greg Wood]

As a new member, I hope I am posting correctly. Bear with me if not !

I found a posting by Earle Oxner that very closely matches the situation we are in. Sadly, there were no replies to his post, so I am asking a similar question. We have developed a .Net Compact Framework 2 forms application & deployed it on a 2 PDAs, one running Windows Mobile 2003 2nd Edition and one running Windows Mobile v5.

The app's purpose is to POST data to an HTTPS url and the code is below

Public Shared Function Send(ByVal URL As String, _
        Optional ByVal PostData As String = "", _
        Optional ByVal Method As HTTPMethod = HTTPMethod.HTTP_GET, _
        Optional ByVal ContentType As String = "")
 
        Dim Request As HttpWebRequest = WebRequest.Create(URL) ' opens a connection to the URL 
        Dim Response As HttpWebResponse
        Dim SW As StreamWriter
        Dim SR As StreamReader
        Dim ResponseData As String
        Dim flag As Boolean
        ' Prepare Request Object
        Request.Method = Method.ToString().Substring(5) 'find out if it's a POST or GET.  
 
        ' Set form/post content-type if necessary
        If (Method = HTTPMethod.HTTP_POST AndAlso PostData <> "" AndAlso ContentType = "") Then
            ContentType = "application/x-www-form-urlencoded"
        End If
 
        ' Set Content-Type
        If (ContentType <> "") Then
            Request.ContentType = ContentType
            Request.ContentLength = PostData.Length
        End If
 
        flag = False 'set to false, if we instantiate SW then it will be set to true so that the Finally knows whether to kill it or not.
        ' Send Request, If Request
        If (Method = HTTPMethod.HTTP_POST) Then
            Try
                SW = New StreamWriter(Request.GetRequestStream()) 'new stream writer to the open connection. 
                flag = True
                SW.Write(PostData) 'write the data to the open connection.
            Catch Ex As Exception
                'handle any errors here; return a string to say it failed.
                'Throw Ex'this was the default action that caused a crash.
                Return "Failure to send"
                Exit Function
            Finally
                If flag Then
                    SW.Close()
                End If
            End Try
        End If
 
        ' Receive Response
        flag = False 'reset the flag for the next block
        Try
            Response = Request.GetResponse
            SR = New StreamReader(Response.GetResponseStream())
            flag = True
            ResponseData = SR.ReadToEnd()
        Catch Wex As System.Net.WebException
            SR = New StreamReader(Wex.Response.GetResponseStream())
            ResponseData = SR.ReadToEnd()
            Throw New Exception(ResponseData)
        Finally
            If flag Then
                SR.Close()
            End If
        End Try
 
        'we now have a response from the server, probably a positive one.
        ' need to find the phrase 'Message received successfully'
        Dim result As Integer = InStr(ResponseData, "Message received successfully", CompareMethod.Text)
        'MsgBox(result)
        If result <> 0 Then
            'it was successfull.
            Return "Success"
        Else
            Return "Failure"
        End If
 
        Return ResponseData
    End Function 

When the URL parameter is a valid http: address, the code works fine. When it is a https: address, it fails at the line
SW = New StreamWriter(Request.GetRequestStream())

We tried installing a Certificate on the PDA and offering it by addressing the same https url through Internet Explorer before then running the application. We hoped this would allow the app to use the previously-certificated connection, but it failed as before.

Next we thought about certificating in code within the app and found a posting on Jan Tielens' Blog site suggesting this was possible. However, it turned out that the ICertificatePolicy interface could not be accessed in an app using the Compact Framework (which ours is)

Now we are stuck ! Any help on using the Compact Framework version of VB.Net to programatically broker an HTTPS connection would be greatly appreciated

[radcaesar]

Along with enabling SSL on the Windows Mobile 2003 for Smartphone agent, you will also need to enable SSL on the Device Manager server.

Have u done with that ?

:)

[Greg Wood]

Along with enabling SSL on the Windows Mobile 2003 for Smartphone agent, you will also need to enable SSL on the Device Manager server.

Have u done with that ?

:)

Hello radcaesar,

Although we could not find any setting on the PDA's o/s that related to enabling SSL, we can make an https connection on the device when we use Internet Explorer browser, so I assume SSL is enabled and correctly configured on the server (actually an iChain server) and the PDA device itself. Problems arise when trying to make the connection using the VB.Net app rather than the browser.