GDAX Post API not working VB.net
your "Public Shared Function GetSignature" works fine! I have been racking my head for a couple of days writing my own but with no luck! Thanks for your snippet!

As far as your problem someone may have already answered it.

To troubleshoot further problems I recommend after you get an HTTP Error to continue your stream and GDAX will give you helpful information.

here is how I handle a web exception.

          Catch ex As WebException

        Dim output As New ClassWebRequestOutput
        output._ErrorMessage = ex.Message.ToString

        Dim exResponse As String
        output._Error = True

        exResponse = New StreamReader(ex.Response.GetResponseStream()).ReadToEnd
        output._Resopnse = exResponse

        Return output
        Exit Function


This continues the web connection with helpful hints.