[Aerogear-users] Aerogear Unified Push registration through a server backend

Alex Ballesté alexandre.balleste at udl.cat
Wed May 20 04:01:56 EDT 2015


Hi,
Yes, I was talking about getting the notifications with another deviceToken.

Normal flow:

User Good Guy -> download app -> Auths -> register to UPS sending

     {
     deviceToken: good_guy_device_token
     variantID: VID,
     variantSecret: VS
     alias: user_good_guy
     categories: [empty in my case]
}

Ok - success

Malicious flow:

User Hacker Guy -> download app -> explores the code/debug with Chrome-> 
Manipulates the authorization result and goes to the registration line 
and sends:
{
     deviceToken: hack_guy_device_token
     variantID: VID,
     variantSecret: VS,
     alias: user_good_guy <--- or other valid username
     categories:  [empty in my case]
}

Ok- success

Then teacher sends a message and produces a notification to UPS in which 
'user_good_guy' is in the list of alias. Then Good guy and Hacker guy 
will receive the notification, each in their devices. Isn't it?

Thanks for the patience with my doubts. You are bringing me a great support

Alex.


El 20/05/15 a les 09:33, Erik Jan de Wit ha escrit:
> Hi Alex,
>
> I think you didn't get what I was saying before, so you want to
> protect UPS so that these hacker students don't get all the
> notifications. Say I'm such a student so I unpack the cordova app and
> I have the variantId and secret. So I can create a POST on UPS to
> change the alias or category but what I need is also the device token
> that is used by the native push network. If I don't use the same one
> that the app uses then I'll end up registering an second device
> instead of modifying. So in order to modify I'll need to intercept the
> initial POST to UPS see what device token is used then modify that.
> Even if I get that to work the device token changes from time to time
> so I'll only able to get all the notifications for a short period of
> time.
>
> On android I could create my own app that uses the same variantId and
> secret as your app and then register itself as a second device with
> different alias or category. This would not work on iOS as it would
> also have to use the same bundleId, but this is unique and linked to a
> certificate.
>
> So protecting UPS to prevent students from tinkering might not be
> worth the effort as it's not a simple POST to update the alias or
> category.
>
> On Tue, May 19, 2015 at 2:36 PM, Alex Ballesté
> <alexandre.balleste at udl.cat> wrote:
>> Thanks for your advise Matthias,
>>
>> I understand that categories are the strong feature of UPS letting you to
>> send a push notification to one or more categories and then notification
>> will arrive to all devices subscribed to those categories.
>> In my case the categories don't help a lot because members of our course
>> sites change frequently and maintain this relationship device-categories
>> would be very difficult to maintain. For this reason I thought to use alias
>> instead of categories.
>>
>> By the other hand I understand that in the authentication methods you pasted
>> me relays security on the APP code execution. If code is native like those
>> you put, the risk to be hacked is less than using a framework like cordova.
>> I'm using aerogear cordova push plug-in and if I want to authenticate first
>> I must do it on JS and it's very vulnerable.
>>
>> I know that I always have the options of change my development framework
>> stack or build my "vitamined" cordova plugin, but I want to look for other
>> options first :-D
>>
>> In the last paragraph I wrote in my last email I mean that in order to use
>> cordova plugin you must provide JSON object with parameter senderID,
>> variantID, variantSecret. In hybrid apps those parameter are exposed to be
>> read them easily and it's also easy to manipulate REST calls to the UPS to
>> associate the device to other categories or assign other alias ... just it.
>> I was looking to proxy-ing to be sure that alias was the same that the
>> username that logged in the Backend.
>>
>> Sorry for bothering you guys.
>>
>> Alex.
>>
>>
>>
>>
>> El 19/05/15 a les 12:03, Matthias Wessendorf ha escrit:
>>
>>
>>
>> On Tue, May 19, 2015 at 9:40 AM, Alex Ballesté <alexandre.balleste at udl.cat>
>> wrote:
>>> Hi Erik, thanks for answering so quickly. I still have some gaps in my
>>> mind; I'm sure that is because my inexperience in that area. Maybe I was
>>> wrong choosing UPS for covering use case that was not designed for but I
>>> still think (correct me if I'm wrong) that this scenario is possible:
>>>
>>> Our Learning Management System (LMS) Sakai distributes users into "sites"
>>> corresponding to courses. Each student belong to many sites. An instructor
>>> from a course can send announcements, messages, upload resources, etc to a
>>> particular course site and those are only visible to the members of the
>>> site.
>>>
>>> We would like to reproduce that behaviour with UPS. When a user sends an
>>> announcement to site (and a checkbox is marked) it sends the notification to
>>> the Messaging backend who automatically sends the notification with an array
>>> of alias filled with the "username" of members of that site. It helps to us
>>> to limit who receives a notification from which site ...
>>
>> we have a category
>>
>> the users device just subscribes to a category or more.
>>
>>
>>
>>
>> Now, on the backend, so something like:
>>
>> final UnifiedMessage unifiedMessage = UnifiedMessage
>>      .withMessage()
>>         .alert("Some Text")
>>         .sound("default")
>>      .criteria()
>>         .categories("Class A") // or pass in more... if desired
>> .build();
>>
>> sender.send(unifiedMessage, () ->
>>      logger.info("successful delivery to UPS returned")
>> );
>>
>>
>>
>>
>>
>>
>>>
>>> Our intention with our APP is to authenticate first, to be sure that is an
>>> student of our university, so registration to the UPS must be done when auth
>>> succeed (don't let anybody who downloaded the app register to the UPS if
>>> don't belong to our institution).
>>
>> yes, we do that too:
>> iOS:
>> https://github.com/aerogear/aerogear-ios-cookbook/blob/1.6.x/AeroDoc/AeroDoc/Classes/Controllers/AGLoginViewController.m#L153-L174
>> Andrid:
>> https://github.com/aerogear/aerogear-android-cookbook/blob/27b9791713b9c77a2f01600ab487e8467cc62431/AeroDoc/app/src/main/java/org/jboss/aerogear/android/cookbook/aerodoc/activities/AeroDocActivity.java#L158-L167
>>
>>>
>>> Any time, user can choose to disconnect his account from the APP, so we
>>> developed that when user disconnects their account from the APP it calls to
>>> unregister, because we don't want that the APP receives more notifications.
>>> (Maybe that is our first mistake?)
>>
>> remove the cateory
>>> I don't know how the UPS protects from another app to use the same
>>> projectID to register to the service (I'll dive deeper to be sure I'm doing
>>> things well), but I can't imagine another way to prevent  that a user with
>>> our APP manipulate the calls to UPS with other alias or categories, exposing
>>> the notifications created from other LMS sites. I know that it's not a
>>> critical situation because notifications should be not used to send
>>> sensitive data, but we would like to prevent it in some way.
>>
>> not sure what you mean here
>>
>>>
>>> Thanks,
>>>
>>> Alex.
>>>
>>>
>>>
>>> El 18/05/15 a les 14:47, Erik Jan de Wit ha escrit:
>>>
>>> The problem is that you don't want/need to call unregister in a normal
>>> flow. Unregister is used for instance when a new version of you app
>>> drops support for push notifications.
>>>
>>> I don't get why you are proxy-ing the requests to UPS, because you
>>> cannot have 2 applications receiving the same push notifications. On
>>> iOS the bundle id makes sure of that, and on android there is the
>>> unique project id. So even if a second app would register with UPS it
>>> will not get the push notifications.
>>>
>>> On Mon, May 18, 2015 at 2:12 PM, Alex Ballesté
>>> <alexandre.balleste at udl.cat> wrote:
>>>
>>> Hi, I'm developing a mobile app for android and ios for our University. It
>>> will use AeroGear Unified Push Server to send notifications to students
>>> when
>>> a new announcement is sent in our LMS.
>>>
>>> We are developing the app with ionic framework and we are using the
>>> register
>>> and unregister process through a custom backend service instead of direct
>>> from device.
>>>
>>> We use the cordova plugin and we call registers and unregister JS methods,
>>> but we don't point to the push server endpoint, but backend server
>>> instead.
>>> Once the Backend server gets the requests it creates a new request to Push
>>> server providing variantSecret and variantID; the response received is
>>> sent
>>> back to the app.
>>>
>>> We would like to use this flow for security reasons. We want to avoid that
>>> the users do their own apps and use those values to register and supply
>>> alias to get users notifications. So backend handles the security (tokens,
>>> deviceids, usernames, ... ) and if everything is ok then proxies then
>>> backend generates a new request fullfilling alias and real authentication
>>> parameters and the received parameters from app. We achieved the
>>> registation
>>> and unregistration, but when unregistration process is done if we do a new
>>> re-registration then we got a success response, but then notification
>>> didn't
>>> arrive.
>>>
>>> Has anybody did something similar to this approximation? Do you have any
>>> advise or trick that would be useful for us?
>>>
>>> Thanks in advance
>>>
>>> Alex
>>>
>>>
>>>
>>> --
>>>
>>> Alexandre Ballesté Crevillén alexandre.balleste at udl.cat
>>> ====================
>>> Universitat de Lleida
>>>
>>> Àrea de sistemes d'Informació i Comunicacions
>>>
>>> Analista/Programador
>>>
>>>
>>> University of Lleida
>>>
>>> Information and Communication Systems Service
>>>
>>>
>>> Tlf: +34 973 702148
>>>
>>> Fax: +34 973 702130
>>>
>>> =====================
>>>
>>> Avís legal/Aviso legal/Avertiment legal/Legal notice
>>>
>>>
>>> _______________________________________________
>>> Aerogear-users mailing list
>>> Aerogear-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/aerogear-users
>>>
>>>
>>>
>>> --
>>>
>>> Alexandre Ballesté Crevillén alexandre.balleste at udl.cat
>>> ====================
>>> Universitat de Lleida
>>>
>>> Àrea de sistemes d'Informació i Comunicacions
>>>
>>> Analista/Programador
>>>
>>>
>>> University of Lleida
>>>
>>> Information and Communication Systems Service
>>>
>>>
>>> Tlf: +34 973 702148
>>>
>>> Fax: +34 973 702130
>>>
>>> =====================
>>>
>>> Avís legal/Aviso legal/Avertiment legal/Legal notice
>>>
>>>
>>> _______________________________________________
>>> Aerogear-users mailing list
>>> Aerogear-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/aerogear-users
>>>
>>
>>
>> --
>> Matthias Wessendorf
>>
>> blog: http://matthiaswessendorf.wordpress.com/
>> sessions: http://www.slideshare.net/mwessendorf
>> twitter: http://twitter.com/mwessendorf
>>
>>
>> _______________________________________________
>> Aerogear-users mailing list
>> Aerogear-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/aerogear-users
>>
>>
>>
>> --
>>
>> Alexandre Ballesté Crevillén alexandre.balleste at udl.cat
>> ====================
>> Universitat de Lleida
>>
>> Àrea de sistemes d'Informació i Comunicacions
>>
>> Analista/Programador
>>
>>
>> University of Lleida
>>
>> Information and Communication Systems Service
>>
>>
>> Tlf: +34 973 702148
>>
>> Fax: +34 973 702130
>>
>> =====================
>>
>> Avís legal/Aviso legal/Avertiment legal/Legal notice
>>
>>
>> _______________________________________________
>> Aerogear-users mailing list
>> Aerogear-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/aerogear-users
>>
>
>


-- 

Alexandre Ballesté Crevillén alexandre.balleste at udl.cat
====================
Universitat de Lleida

Àrea de sistemes d'Informació i Comunicacions

Analista/Programador


University of Lleida

Information and Communication Systems Service


Tlf: +34 973 702148

Fax: +34 973 702130

=====================

Avís legal/Aviso legal/Avertiment legal/Legal notice 
<http://www.imatge.udl.cat/avis_legal_lopd.html>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/aerogear-users/attachments/20150520/80192887/attachment.html 


More information about the Aerogear-users mailing list