hash sha256 calculation

Hi Sergei, 

This sample did the trick indeed.... however the "EncodeBase64" function leads to an #VALUE! when called from the spreadsheet. What can be the explaination for this?

Public Function BASE64SHA1(ByVal sTextToHash As String)

Dim asc As Object
    Dim enc As Object
    Dim TextToHash() As Byte
    Dim SharedSecretKey() As Byte
    Dim bytes() As Byte
    Const cutoff As Integer = 5

Set asc = CreateObject("System.Text.UTF8Encoding")
    Set enc = CreateObject("System.Security.Cryptography.HMACSHA1")

TextToHash = asc.GetBytes_4(sTextToHash)
    SharedSecretKey = asc.GetBytes_4(sTextToHash)
    enc.Key = SharedSecretKey

bytes = enc.ComputeHash_2((TextToHash))
    BASE64SHA1 = EncodeBase64(bytes)
    BASE64SHA1 = Left(BASE64SHA1, cutoff)

Set asc = Nothing
    Set enc = Nothing

End Function

Private Function EncodeBase64(ByRef arrData() As Byte) As String

Dim objXML As Object
    Dim objNode As Object

Set objXML = CreateObject("MSXML2.DOMDocument")
    Set objNode = objXML.createElement("b64")

objNode.DataType = "bin.base64"
    objNode.nodeTypedValue = arrData
    EncodeBase64 = objNode.text

Set objNode = Nothing
    Set objXML = Nothing

End Function