How to do http basic authentication from Excel with VBA

I had some questions about authentication from users of the Excel Rest library. Typically Rest queries are authorized through the use of a developer key issued to registered users, but some sites need authorization as well.

HTTP basic authorization is accomplished by encoding a username and password into the headers of a request, and although there is plenty of information out there about how to do this with jQuery and javaScript and other languages, tracking down the solution from VBA was a little more difficult.

The solution is as below, with acknowledgement to  http://pastie.org/1192157

Public Function httpGET(fn As String, _
        Optional authUser As String = vbNullString, _
        Optional authPass As String = vbNullString) As String
    pHtml = fn
    Dim oHttp As Object
    Set oHttp = CreateObject("Microsoft.XMLHTTP")
    Call oHttp.Open("GET", pHtml, False)
    If (authUser <> vbNullString) Then
    ' need to do basic authentication
    ' acknowledgement to http://pastie.org/1192157
        oHttp.SetRequestHeader "Content-Type", "application/json"
        oHttp.SetRequestHeader "Accept", "application/json"
        oHttp.SetRequestHeader "Authorization", "Basic " + _
            Base64Encode(authUser + ":" + authPass)
    End If
    Call oHttp.Send("")
    httpGET = oHttp.ResponseText
    Set oHttp = Nothing
End Function

 

Public Sub testneedsPass()
    Dim cr As cRest
    Set cr = restQuery("needsPass", "needsPass", _
    , , , , , True, , , True, , "someuser", "somepassword")
                 
End Sub