Access Denied when checking file exists on sharepoint from vba - vba

Question

I am trying to check if a file exists in SharePoint 2010 from Excel 2010 VBA. I took this code from another question.
Function checkFile(URLStr As String) As Boolean
Dim oHttpRequest As Object
Set oHttpRequest = New MSXML2.XMLHTTP60
With oHttpRequest
.Open "GET", URLStr, False
.setRequestHeader "Cache-Control", "no-cache"
.setRequestHeader "Pragma", "no-cache"
.setRequestHeader "If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT"
.send
End With
If oHttpRequest.Status = 200 Then
checkFile = True
Else
checkFile = False
End If
End Function
When I do so, vba is throwing an error: 'Access Denied Error for this object'
It fails on the line .send
I figured out that the error code is -2147024891.
I checked the Sharepoint permissions and they should be fine.

Answer 1

My URL with http, but access to sharepoint is granted with https only (at lest at a certain version). Changing the URL solved the access issues.

Answer 2

Function checkFile( URLStr As String) As Boolean
Dim oHttpRequest As Object
Dim GetResult As Integer
Set oHttpRequest = New MSXML2.XMLHTTP60
With oHttpRequest
.Open "GET", URLStr, False
.setRequestHeader "Cache-Control", "no-cache"
.setRequestHeader "Pragma", "no-cache"
.setRequestHeader "If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT"
End With
On Error GoTo HttpError
oHttpRequest.send '!!!!!!here code stops!!!!!!!
HttpError:
GetResult = 00
GetResult = oHttpRequest.Status
If GetResult = 200 Then
checkFile = True
Else
checkFile = False
End If
End Function

Answer 3

You need to define the authentication user info.
oHttp.SetRequestHeader "Authorization", "Basic " + _
Base64Encode(authUser + ":" + authPass)
Here is some info
http://ramblings.mcpher.com/Home/excelquirks/snippets/basicauth
How to pass authentication credentials in VBA