base64 image decoder for ASP classic
Can any one tell me how to decode a base64 encoded image in classic ASP? The image is encoded by Java org.apache 开发者_C百科base64 class. The Java uses RFC 2045 for base64 decoding.
<%
Set objXML = Server.CreateObject("MSXml2.DOMDocument")
Set objDocElem = objXML.createElement("Base64Data")
objDocElem.DataType = "bin.base64"
objDocElem.text = "/9j/4AAQSkZJRgABAQEBLAEsAAD/2wBDAAUD" 'encodedString
'Save to disk
Set objStream = Server.CreateObject("ADODB.Stream")
objStream.Type = 1
objStream.Open
objStream.Write objDocElem.NodeTypedValue
objStream.SaveToFile "abc.jpg", 2
set objStream = Nothing
'Or send to browser
Response.ContentType = "image/jpeg"
Response.AddHeader "Content-Disposition", "attachment; filename=abc.jpg";
Response.BinaryWrite objDocElem.NodeTypedValue
Set objXML = Nothing
Set objDocElem = Nothing
%>
You can use the Capicom COM object. I've been using it to to the reverse (base64 encoding). This is what I would do (if you've got a big loop, you'd better have the CreateObject done outside the loop, but in simple cases this should do it):
Function Base64Decode(encodedString)
Dim caputil : Set caputil = CreateObject("CAPICOM.Utilities")
If len(encodedString) > 0 Then
Base64Decode = caputil.Base64Decode(encodedString)
Else
Base64Decode = ""
End If
Set caputil = Nothing
End Property
Reference : http://msdn.microsoft.com/en-us/library/aa388176(v=vs.85).aspx
By the way, capicom.dll can be downloaded from MS site : http://www.microsoft.com/downloads/en/details.aspx?FamilyID=860ee43a-a843-462f-abb5-ff88ea5896f6
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