A Colleague was working on removing a 3rd party component from an old ASP website. The only function still being provided by the 3rd party component was Base64 encoding. He was trying to get Base64 working directly in vbscript. We eventually decided to go with a VB6 DLL that would expose Encode/Decode functions which in turn would use the MSXML library to create a Base64 encoded string.
Here's the code...
Option Explicit
Public Function Encode(ByRef StringToEncode As String) As String
Dim lobjXML As MSXML2.DOMDocument
Dim lobjNode As MSXML2.IXMLDOMElement
Dim lConvertedString() As Byte
Set lobjXML = New MSXML2.DOMDocument
Set lobjNode = objXML.createElement("b64")
lobjNode.dataType = "bin.base64"
ConvertedString = StrConv(StringToEncode, vbFromUnicode) ' Convert to ByteArray
lobjNode.nodeTypedValue = ConvertedString
Encode = lobjNode.Text
Set lobjNode = Nothing
Set lobjXML = Nothing
End Function
Public Function Decode(ByVal EncodedString As String) As String
Dim lobjXML As MSXML2.DOMDocument
Dim lobjNode As MSXML2.IXMLDOMElement
Dim lDecodedString As String
Set lobjXML = New MSXML2.DOMDocument
Set lobjNode = objXML.createElement("b64")
lobjNode.dataType = "bin.base64"
lobjNode.Text = strData
Decode = StrConv(lobjNode.nodeTypedValue, vbUnicode) 'Convert it back into a string to return
Set lobjNode = Nothing
Set lobjXML = Nothing
End Function