Module Eliom_openid

module Eliom_openid: sig .. end
OpenID identification


This module implements the Relying Party of the OpenID specification, in stateful mode.

Library description



The library provides means to authenticate an user to a remote provider using the OpenID protocol. Basically, you need to ask the user its OpenID url, and the fields you want to require (or none, if you just want to authenticate an user), along with other information.

The library uses an "hidden service" that is needed when the provider redirects back to your site. This service is registered in the library, all you have to do is to give a path for that service and a default handler (if the user connects to that service without being in an authentication process.) Here is a short example of how to use the library

open Eliom_openid
let messages = Eliom_state.create_volatile_table ()
(* The login form *)
let login_form = Eliom_service.new_service
  ~path:["login-form"]
  ~get_params: Eliom_parameter.unit
  ()

(* Initialize the library, and getting the authenticate function *)
let authenticate = Eliom_openid.init ~path:["__openid_return_service"]
    ~f: (fun _ _ -> Eliom_registration.Redirection.send login_form)

(* Create the handler for the form *)
(* We have to use Eliom_registration.String_redirection as we
   redirect the user to her provider *)
let form_handler = Eliom_registration.String_redirection.register_new_post_coservice
    ~fallback: login_form
    ~post_params: (Eliom_parameter.string "url")
    (fun _ url ->
       authenticate
    ~max_auth_age: 4 (* Requires that if the user logged in more that 4 seconds ago
                        he needs to relog in *)
    ~required: [Eliom_openid.Email] (* Requires his e-mail *)
    ~immediate: false
   url
   (fun result ->
     let string =
       match result with
         | Setup_needed -> "setup needed" | Canceled -> "canceled"
         | Result result ->
           try List.assoc Email result.fields with Not_found -> "No e-mail :("
     in
     Eliom_state.set_volatile_session_data ~table:messages string;
     Eliom_registration.Redirection.send login_form))

open XHTML
let _ = Eliom_registration.Xhtml.register
    ~service: login_form
    (fun _ _ ->
    (match Eliom_state.get_volatile_session_data ~table: messages () with
     | Eliom_state.Data s ->
       Eliom_state.discard () >>= fun () ->
       Lwt.return [p [pcdata ("Authentication result: "^ s)]]
     | _ -> Lwt.return []) >>= fun message ->
    let form =
    Eliom_registration.Xhtml.post_form ~service:form_handler
      (fun url ->
        [p [pcdata "Your OpenID identifier: ";
            Eliom_registration.Xhtml.string_input ~input_type:`Text ~name:url ();
            Eliom_registration.Xhtml.string_input ~input_type:`Submit ~value:"Login" ();
           ]]) ()
    in
    Lwt.return
      (html
           (head (title (pcdata "A sample test")) [])
           (body
              (message @ [form]))))


Documentation



Miscallenous


type openid_error = 
| Invalid_XRDS_File of string * string (*The provider XRDS file was not valid*)
| Discovery_Error of string * string (*An error occured during the discovery of the provider*)
| Missing_parameter of string (*The remote server forgot a parameter in its request*)
| Invalid_signature of string * string (*We disagree with the server's signature*)
| Invalid_association of string (*We were unable to associate with a provider*)
| Invalid_argument of string * string * string (*The argument provided were not set to a correct value*)
| Server_error of string (*The server threw an explicit error*)
| Invalid_answer of string (*The answer code was not correct*)
| Invalid_html_doc of string
Error that may happen when identifiying an user

An error occured during the parsing of an user url in html format
val string_of_openid_error : openid_error -> string
Prettyprint an OpenID Error
exception Error of openid_error
Exception thrown by this module's function.
type field = 
| Email
| Fullname
| DateOfBirth
| PostCode
| Timezone
| Language
| Country
| Gender
| Nickname
A field you can request to the provider
type 'a extension = {
   headers : (string * string) list;
   parse : (string * string) list -> 'a Lwt.t;
}
An extension yielding values of type 'a
val sreg : ?policy_url:string ->
required:field list ->
optional:field list ->
unit -> (field * string) list extension
The SREG extension
See also SREG
val ax : required:field list ->
optional:field list ->
unit -> (field * string) list extension
The AX extension
See also AX
type pape = {
   auth_time : string option; (*The time at which the user last logged in*)
   policies : string list option; (*A list of policies (url) describing your usage of the data*)
   nist_level : int option;
}
The pape data returned by the server
val pape : ?max_auth_age:int ->
?auth_policies:string list ->
unit -> pape extension
The nist level
val ( *** ) : 'a extension ->
'b extension -> ('a * 'b) extension
The PAPE extension.
See also PAPE

Product of two extension
type 'a authentication_result = 
| Canceled (*The user canceled the login (or failed)*)
| Setup_needed (*The provider has not enough information to complete an immediate request. Only returned when using an immediate authentication.*)
| Result of 'a
The result of an authentication.

All went ok.

Low-level interface.


val perform_discovery : string -> (string * string option) Lwt.t
Perform discovery on an user-supplied url
module type HiddenServiceInfo = sig .. end
Information about the hidden service

The function called when an user connects to the hidden service (not that hidden) without being in an identication process. Typically you should redirect the user to the login page.
module Make: 
functor (S : HiddenServiceInfo) -> sig .. end
This functor build a hidden service that will be used to receive the remote server's data.

Authenticate an user.

High-level interface



The high-level interface takes care of creating the extension you want, without to use them directly. It yields a result.
type result = {
   fields : (field * string) list; (*The fields you requested*)
   pape : pape;
}
The result yielded by the authentication process

The pape information
type check_fun = ?immediate:bool ->
?policy_url:string ->
?max_auth_age:int ->
?auth_policies:string list ->
?required:field list ->
?optional:field list ->
string ->
(result authentication_result ->
(Eliom_registration.browser_content, Eliom_registration.http_service)
Eliom_registration.kind Lwt.t) ->
Eliom_lib.Url.t Lwt.t
The type of the authenticate function.
val init : path:string list ->
f:((string * string) list ->
unit ->
(Eliom_registration.browser_content, Eliom_registration.http_service)
Eliom_registration.kind Lwt.t) ->
check_fun
Init the OpenID for your site. Takes a path and a handler for the hidden service