Classic ASP
Duo Auth API - Preauth

The /preauth endpoint determines whether a user is authorized to log in, and (if so) returns the user's available authentication factors.
Chilkat Classic ASP Downloads

Download Chilkat for Classic ASP
Classic ASP
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

integrationKey = "DIMS3V5QDVG9J9ABRXC4"
secretKey = "HWVQ46nubLBxhnRlKddTltWIi3hL0fIQF2qTvLab"

set http = Server.CreateObject("Chilkat.Http")

http.Accept = "application/json"

' Use your own hostname here:
url = "https://api-a03782e1.duosecurity.com/auth/v2/preauth"

http.Login = integrationKey
http.Password = secretKey

set req = Server.CreateObject("Chilkat.HttpRequest")
req.AddParam "username","matt"

req.HttpVerb = "POST"
req.ContentType = "application/x-www-form-urlencoded"

set resp = Server.CreateObject("Chilkat.HttpResponse")
success = http.HttpReq(url,req,resp)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( http.LastErrorText) & "</pre>"
    Response.End
End If

Response.Write "<pre>" & Server.HTMLEncode( "status code = " & resp.StatusCode) & "</pre>"

set json = Server.CreateObject("Chilkat.JsonObject")
success = json.Load(resp.BodyStr)
json.EmitCompact = 0
Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"

' Sample successful output:

' status code = 200

' {
'   "response": {
'     "devices": [
'       {
'         "capabilities": [
'           "auto",
'           "push",
'           "sms",
'           "mobile_otp"
'         ],
'         "device": "DP6GYVTQ5NK82BMR851F",
'         "display_name": "iOS (XXX-XXX-1871)",
'         "name": "",
'         "number": "XXX-XXX-1871",
'         "type": "phone"
'       }
'     ],
'     "result": "auth",
'     "status_msg": "Account is active"
'   },
'   "stat": "OK"
' }

' Sample code to parse the above JSON response..

' Use this online tool to generate parsing code from sample JSON: 
' Generate Parsing Code from JSON

responseResult = json.StringOf("response.result")
responseStatus_msg = json.StringOf("response.status_msg")
stat = json.StringOf("stat")
i = 0
count_i = json.SizeOfArray("response.devices")
Do While i < count_i
    json.I = i
    device = json.StringOf("response.devices[i].device")
    display_name = json.StringOf("response.devices[i].display_name")
    name = json.StringOf("response.devices[i].name")
    number = json.StringOf("response.devices[i].number")
    v_type = json.StringOf("response.devices[i].type")
    j = 0
    count_j = json.SizeOfArray("response.devices[i].capabilities")
    Do While j < count_j
        json.J = j
        strVal = json.StringOf("response.devices[i].capabilities[j]")
        j = j + 1
    Loop
    i = i + 1
Loop

%>
</body>
</html>