VBscript for making a GET request to Duo's Auth API

duo_auth_api.vbs

Function ToString(rabyt,datatype)
    With CreateObject("MSXML2.DOMDocument")
        .LoadXML "<root />"
        .DocumentElement.DataType = datatype
        .DocumentElement.nodeTypedValue = rabyt
        ToString = Replace(.DocumentElement.text, vbLf, "")
    End With
End Function

Function ToSHA1HMAC(sTextToHash, sSharedSecretKey)
    Dim asc, enc, hex, bytes, TextToHash, SharedSecretKey
    Set asc = CreateObject("System.Text.UTF8Encoding")
    Set enc = CreateObject("System.Security.Cryptography.HMACSHA1")
    TextToHash = asc.Getbytes_4(sTextToHash)
    SharedSecretKey = asc.Getbytes_4(sSharedSecretKey)
    enc.Key = SharedSecretKey
    bytes = enc.ComputeHash_2((TextToHash))
    hex = ToString(bytes,"bin.Hex")
    hex = asc.Getbytes_4(hex)
    base64 = ToString(hex,"bin.base64")
    ToSHA1HMAC = base64
End Function

Function LPad(s, l, c)
    Dim n : n = 0
    If l > Len(s) Then n = l - Len(s)
    LPad = String(n, c) & s
End Function

Function WebRequest(apihost,reqpath,method,date,auth,params)
    set webclient = CreateObject("Microsoft.XMLHTTP")
    webclient.open method,"https://" & apihost & reqpath,False
    webclient.setRequestHeader "Date", "date"
    Dim req, ikey
    req = date & "\n" & method & "\n" & apihost & "\n" & reqpath & "\n" & params
    auth = ToSHA1HMAC(req,"<SECRET_KEY>")
    ikey = "<INTEGRATION_KEY>"
    auth = "Basic " & ikey & ":" & auth
    webclient.setRequestHeader "Authorization", auth
    Dim resp
    webclient.send
    msgbox webclient.responseText
End Function

Dim d, month, day, dayname, year, hour, minute, second, dtStr
Set d = CreateObject("WbemScripting.SWbemDateTime")    
d.SetVarDate (now())
d = d.GetVarDate(false)
month = Left(MonthName(DatePart("m",d)),3)
year = DatePart("yyyy",d)
day = LPad(DatePart("d",d),2,"0")
dayname = WeekdayName(DatePart("d",d),1,2)
hour = LPad(DatePart("h",d),2,"0")
minute = LPad(DatePart("n",d),2,"0")
second = LPad(DatePart("s",d),2,"0")
dtStr = dayname & ", " & day & " " & month & " " & year & " " & hour & ":" & minute & ":" & second & " GMT"
WebRequest "<API_HOST>","/auth/v2/ping","GET",dtStr,"",""