Visual Basic

'Build and assign values to hashing and header variables
Dim m_method As String = "POST"
Dim m_type As String = "application/xml"
'Dim m_time As String = DateTime.UtcNow.ToString("yyyy-MM-ddTHH:mm:ssZ")
Dim m_time As String = "2015-01-04T20:51:54Z"
Dim m_uri As String = "/transaction/v12"
Dim m_hashData As String = m_method & "\n" & m_type & "\n" & hashed_content & "\n" & m_time & "\n" + m_uri

'Compute the HMAC and convert to a base64 hash
Dim m_hmac_sha1 As New HMACSHA1(Encoding.UTF8.GetBytes(m_key))
Dim m_hmac_data() As Byte = m_hmac_sha1.ComputeHash(Encoding.UTF8.GetBytes(m_hashData))
Dim m_base64_hash As String = Convert.ToBase64String(m_hmac_data)

Dim bitmap As Bitmap = Nothing
 Dim ex As DPFP.Processing.FeatureExtraction
 Dim convertor As New DPFP.Capture.SampleConversion
 Dim fbyte As Byte() = set2.Tables(0).DefaultView.Item(0).Item(1)
 Dim stream As IO.MemoryStream = New IO.MemoryStream(fbyte)
 a.DeSerialize(stream)

With Me.subExpenses.Form
       .Filter = "[ExpenseDate] BETWEEN #" & Me.txtSDate & "# AND #" & Me.txtEDate & "#"
        .FilterOn = True
        .FilterOnLoad = True
    End With

Me.subOrders.Form.RecordSource = "SELECT * FROM Orders WHERE ID='" & IdNo & "' AND OrderDate BETWEEN #" & SDate & "# AND #" & EDate & "# ORDER BY OrderDate"

 'Make a tranaction
 Dim txn As New com.firstdata.globalgatewaye4.V14.Transaction

 'Credentials
 txn.ExactID = sCA.Exact_ID
 txn.Password = sCA.Exact_Password

'//////////////////////////////////////////////////////////////////////////////////////
'Transmit the Card Authorization Request

Dim ws As com.firstdata.globalgatewaye4.V14.Service = New com.firstdata.globalgatewaye4.V14.Service
Dim rxn As com.firstdata.globalgatewaye4.V14.TransactionResult = New com.firstdata.globalgatewaye4.V14.TransactionResult
rxn = ws.SendAndCommit(txn)

'//////////////////////////////////////////////////////////////////////////////////////

Private Function transmit_HMAC( _
        ByVal pValue As String) As Integer

        Dim dwExitCode As Integer = 2

        'Generate the Hashed Content
        Dim encoder As ASCIIEncoding = New ASCIIEncoding
        Dim wsdl_bytes() As Byte = encoder.GetBytes(pValue)
        Dim sha1_crypto As SHA1CryptoServiceProvider = New SHA1CryptoServiceProvider
        Dim hash As String = BitConverter.ToString(sha1_crypto.ComputeHash(wsdl_bytes)).Replace("-", "")
        Dim hashed_content As String = hash.ToLower

        'Grab a copy of the keys
        Dim m_keyID As String = My.Resources.HMAC_KEY_ID
        Dim m_key As String = My.Resources.HMAC_KEY

        'Grab a copy of the EndPoint
        Dim m_url As String = My.Resources.endPoint_Demo

        'Build and assign values to hashing and header variables
        Dim m_method As String = "POST\n"
        Dim m_type As String = "application/xml" 'REST XML
        Dim m_time As String = DateTime.UtcNow.ToString("yyyy-MM-ddTHH:mm:ssZ")
        Dim m_uri As String = "/transaction/v14"
        Dim m_hashData As String = m_method & m_type & "\n" & hashed_content & "\n" & m_time & "\n" + m_uri
        Dim m_hmac_sha1 As New HMACSHA1(Encoding.UTF8.GetBytes(m_key))
        Dim m_hmac_data() As Byte = m_hmac_sha1.ComputeHash(Encoding.UTF8.GetBytes(m_hashData))
        Dim m_base64_hash As String = Convert.ToBase64String(m_hmac_data)

        'Build the HTTP Request
        Dim request As HttpWebRequest = HttpWebRequest.Create(m_url)
        request.Method = "POST"
        request.ContentType = m_type
        request.Accept = "*/*"
        request.Headers.Add("x-gge4-date", m_time)
        request.Headers.Add("x-gge4-content-sha1", hashed_content)
        request.Headers.Add("Authorization", "GGE4_API " + m_keyID + ":" + m_base64_hash)
        request.ContentLength = pValue.Length

        Using stream_writer As StreamWriter = New StreamWriter(request.GetRequestStream)
            stream_writer.Write(pValue)

        End Using



        Return dwExitCode


    End Function