Tag: API

I have problems with a (400) incorrect request for POST requests. I can do all get and delete requests using the same signature process, but the text is obviously string.empty. We tested all sorts of JSON formatting to get this working, but it doesn't work. We couldn't find an example of a pre-hash signature to compare with. Unless the POST server time differs from the GET and DELETE server times, we have the correct time stamp because we are within 1 second of the GET / time API call for the server time. GDAX enables authentication of 30 seconds of buffer.

Public Shared Function placeOrder()
    Try
        Dim Body As String = "{""type"":""limit"",""side"":""sell"",""product_id"":""BTC-USD"",""price"":""20000"",""size"":""0.02235229""}"
        Dim ts As String = GetNonce()
        Dim method As String = "/orders"
        Dim str_GDAX_Main As String = "https://api.gdax.com"
        Dim sig As String = GetSignature(ts, "POST", method, Body)
        Dim fr As System.Net.HttpWebRequest
        Dim targetURI As New Uri(str_GDAX_Main & method)
        'Dim response As String

        Dim jsonDataBytes As Byte() = Encoding.UTF8.GetBytes(Body)


        fr = DirectCast(HttpWebRequest.Create(targetURI), System.Net.HttpWebRequest)
        fr.Headers.Add("CB-ACCESS-KEY", config_API_Key)
        fr.Headers.Add("CB-ACCESS-SIGN", sig)
        fr.Headers.Add("CB-ACCESS-TIMESTAMP", ts)
        fr.Headers.Add("CB-ACCESS-PASSPHRASE", config_API_Passphrase)
        fr.UserAgent = UserAgent
        fr.Accept = "application/json"
        fr.Method = "POST"
        fr.ContentLength = jsonDataBytes.Length

        Dim stream = fr.GetRequestStream()
        stream.Write(jsonDataBytes, 0, jsonDataBytes.Length)
        stream.Close()

        Dim response = fr.GetResponse().GetResponseStream()

        Dim reader As New StreamReader(response)
        Dim res = reader.ReadToEnd()
        reader.Close()
        response.Close()
        Return res

        'If (fr.GetResponse().ContentLength > 0) Then
        '    Dim str As New System.IO.StreamReader(fr.GetResponse().GetResponseStream())
        '    response = (str.ReadToEnd())
        '    str.Close()
        'End If

        'Form1.RichTextBox1.Text = (response)
    Catch ex As System.Net.WebException
        MessageBox.Show(ex.Message)
        'Error in accessing the resource, handle it
    End Try
End Function

Public Shared Function GetNonce() As String
    Return (DateTime.UtcNow - New DateTime(1970, 1, 1, 0, 0, 0)).TotalSeconds.ToString()
End Function

Public Shared Function GetSignature(nonce As String, method As String, url As String, body As String) As String
    Dim message As String = String.Concat(nonce, method.ToUpper(), url, body)
    Dim encoding = New ASCIIEncoding()
    Dim keyByte As Byte() = Convert.FromBase64String(config_API_Secret)
    Dim messageBytes As Byte() = encoding.GetBytes(message)
    Using hmacsha256 = New HMACSHA256(keyByte)
        Dim hashmessage As Byte() = hmacsha256.ComputeHash(messageBytes)
        Return Convert.ToBase64String(hashmessage)
    End Using
End Function

We have no idea if our body is wrong or if the URI is wrong or where the problem is. If someone can take a look and find out where our body syntax error is. Or if we should look elsewhere.