OAuth 2.0 on Servers with Multiple Users - Security - oauth-2.0

I've been searching for a similar situation, but don't see one yet. Here's the scenario...
Lets say you have a server that allows multiple people to sign on. There is an application on the server that works with Google Calendar. Anyone can use it.
First, a user must register the service and go through the initial OAuth 2.0 setup. This adds the necessary info (id, token, refresh token, exp time, etc) to a table. Once done, they can use Calendar APIs and in the background the tokens are automatically refreshed.
Now, lets say Bob and Nancy are both set up. What's to stop Nancy from accessing Bob's calendar data as only the ID (ie, bob#gmail.com) is in the Token database and the ID is used to access that specific calendar, but there's no authentication method to USE that actual token record.
Would there be some need to add another layer of authentication to actually accessing a specific record in the Token table? So, before Bob or Nancy can run a addCalendarEvent() type process we'd need to validate it's their ID and not someone else's?
I hope this makes sense. :)

Related

Track anonymous users without forcing users to go through authentication proccess

I want to track all users (both authenticated users and anonymous users) , so far the solution i found are not good.
First of all, we can use a cookie but as we all know its not a reliable solution, second of all we, can use browser finger printing, but until this moment I did not find any solution for server side.
I found this solution valve but it is for client side and this one browserFingerPrint , I want an approach which user does not find any token in request , I want to create the key in server side so I can track users.
Does any one know any solution?
note : my server side technology is Asp.net Mvc
use case : users can comment on m site and also they can like or dislike comments, I want to allow all users to do this and also I want to track users before action (like or dislike)
No, there is no solution for what you want that doesn't use some form of a "token" which fingerprints anonymous users.
Let's see why.
An anonymous browser sends a series of bits of data, such as IP, browser agent and other headers. These should never be used to identify a user because they can be easily forged. They can be OK for tracking, and for most purposes IP address or some hash based on IP address and browser agent is sufficient. However this won't do for things which require security, such as commenter identification.
For commenter identification, it is necessary to prevent fraud. This is typically achieved by giving a unique token to each user. This can be transmitted in many forms, off the top of my head: cookies, headers, query string, POST parameters, or client certificates. However it does require a token issued by the server. If the client can generate a token from scratch, then it follows it can generate a fake token.

How to authenticate Rails application using token from 3rd party API?

I have a Rails application that make several user-specific calls to a third-party API. They interact with a lot of data in the course of filling out a survey, and their progress is stored in HTML5 localStorage until they reach the end of the survey and the data is saved in a local database & localStorage cleared.
The API calls require a token tacked onto the end as an "auth=" parameter. Right now, I have the user log into my app with their username and password to that service, POST those credentials to the "sessions" call of that API, and get a token back in JSON. I store that token in a variable in the controller, and use it to make the successive API calls and present the user's data in my app, etc. etc.
I've learned quite a bit about Rails, but next to nothing about sessions or authentication. Generally speaking, is there anything more I need to do for this to be a secure scenario? I feel like I'm missing something.
Assuming the user's username / password combination for the 3rd party service doesn't hit your servers, seems OK to me.
If your servers see the user's credentials, that's not particularly cool. Instead use OAuth to get 3rd party sign in, and use the token to make requests on behalf of the user. You can usually keep the whole session on the client if you want to avoid saving users to the database.
Storing progress in localstorage sounds fine btw. To preserve values you can have the pages of the form be tabs (so hide the previous form, not a new page) and use:
autocomplete="on"
to signify that the values should be restored to what they were. Try that before writing code to save things to localstorage.

Two tier sign in with Devise (Amazon style)

Let's imagine I have following scenario
User receives an email that there is a new item waiting for her
Clicks on a link and is able to either confirm or reject item (details skipped)
Can then access a list of all her items
The trick is that I would like to allow all this happen without user signing in but then limit access to other parts of the website (like sending an item to another user)
How I see it is that:
when user clicks a link she is signed in but only on tier 1 - with access only to confirm/reject action and read only to index of items (that's when Devise session is created)
when user wants to access other part of the website the sign in page is presented
when user comes to the website just by typing in the url http://example.com and wants to access own account she is asked to sign in.
after sign in session is "promoted" to tier which allows full access
after some time of inactivity session is downgraded to tier 1 for security reasons
My inspiration comes from how Amazon works - you can access in read-only most parts of the account but before performing any destructible actions you need to sign in.
Does anyone have any experience with such approach or can share some blog posts, etc?
I didn's find anything on SO and Google mostly returned things about two-factor auth which is not the case here.
I also understand that there are security concerns with links in email.
I have implemented a very similar behavior few months ago. I don't have very interesting resources to show you but I can explain a bit how you could organize or think about the problem to solve.
Description
For the problem you state, it looks like once you have identified a user, you have two different states you can give him:
limited access (perform certain actions, read most of the resources, etc)
full access (allows them to do anything they would normally do).
Having stated that, what you need to do is figure out in which cases you will give a user each access state (for example):
signing in with email token -> limited access
password -> full access
authentication_token -> full access
omniauth -> full access
After that, you will need to save this information in the user session. This should be done anytime the user is authenticated, as you will know what strategy was used to authenticate the user.
To know if a user can or cannot perform an action you will need two things, know what the user can do, and the current "access state". Depending on those you will decide wether the user is allowed or not to perform a certain action.
Whenever a user can't perform an action and is logged in with limited access you should bring him to the flow for verifying his crendetials. This flow is pretty simple, almost like a sign in but just with the password. Once you verify his crendetials you can upgrade his authorization to a full access one.
Implementation details
I recommend you to create a Authorization model which will represent the "access states" that I mentioned. This model will have to be serialized in the session so you should be able to build it from a simple structure and serialize it again into that structure. The simplest the better (a boolean flag, an array or maybe a hash). For the case mentioned, it looks like a boolean would do the job.
Regarding implementation details, I recommend you implementing this with a Warden after_atuhentication callback.
You could implement this with CanCan by creating you own Ability that would be built with an Authorization instance and a User instance.
I think you're confusing authorization and authentication. Devise is an authentication solution, meaning it handles the "proof me you are who you say you are" part. Authorization is the "Ok, I know who you are, now let's see what can you do". Devise doesn't provide an authorization system beyond the simple "logged/not logged". If you need a more complex authorization system, use an authorization gem. CanCan is very popular.

Opening up part of a secured application without compromising the entire application

There's a subset of users which will not have access to the system I'm implementing in the beginning but I need a mechanism for them to capture data for one specific part of the process.
An authorized user creates the original record for a Person with some basic details i.e. First name, last name etc.
I then create a 'DataRequest' record which has a unique guid and the external user is sent an email with a path which is effectively http://sampleapplication/Person/Complete?guid=xxxx
The external user adds additional details like Date of Birth, Eye colour etc, submits and saves to the DB. The DataRequest for that guid is then expired and cannot be accessed again.
The Complete action doesn't have any authorization as these external users do not have user accounts.
My preference is to force these users to use the system but at this stage I'm not sure it's practical.
Is this a bad practice?
Should I be implementing some additional security on this like a one time password / passcode contained in the email? Are there alternative approaches I should consider?
There's nothing wrong with opening up a section of your site to the public. Tons of websites have secured and unsecured sections. However, there's also nothing saying that you have to expose your secure site at all. You can create another site that merely has access to that change those records and make that site alone, public.
As far as securing the information of the user, passcodes by email are the invention of some developer somewhere with limited mental ability or a severe lack of sleep. If the link is only available by email (not discoverable by search engines and not easily guessable), then anyone with the link will also have the passcode, making the passcode to access the link redundant.
You should however log when the email is used to finish the record and then disallow further uses.

DotNetOpenAuth / WebSecurity Basic Info Exchange

I've gotten a good number of OAuth logins working on my site now. My implementation is based on the WebSecurity classes with amends to the code to suit my needs (I pulled the WebSecurity source into mine).
However I'm now facing a new set of problems. In my application I have opted to make the user email address the login identifier of choice. It's naturally unique and suits this use case.
However, the OAuth "standards" strikes again.
Some providers will return your email address as "username" (Google) some will return the display name (Facebook). As it stands I see two options given my particular scenario:
Option 1
Pull even more framework source code into my solution until I can chase down where the OpenIdRelyingParty class is actually interacted with (via the DotNetOpenAuth.AspNet facade) and make addition information requests from the OpenID Providers.
Option 2
When a user first logs in using an OpenID provider I can display a kind of "complete registration" form that requests missing info based on the provider selected.*
Option 2 is the most immediate and probably the quickest to implement but also includes some code smells through having to do something different based on the provider selected.
Option 1 will take longer but will ultimately make things more future proof. I will need to perform richer interactions down the line so this also has an edge in that regard.
The more I get into the code it does seem that the WebSecurity class itself is actually very limiting as it hides lots of useful DotNetOpenAuth functionality in the name of making integration easier.
Andrew (the author of DNOA) has said that the Attribute Exchange stuff happens in the OpenIdRelyingParty class but I cannot see from the DotNetOpenAuth.AspNet source code where this class is used so I'm unsure of what source would need to be pulled into my code in order to enable the functionality I need.
Has anyone completely something similar?
AttributeExchange only applies to the OpenID Providers (Google and Yahoo!) and you can see the extension used in their respective source files.
I recommend against using email address as the username. Email addresses can be recycled (an account can expire or be closed/canceled and the email address can be reassigned to a new user). If this happens, your site based on email addresses would "give away" all the data of the old user to the new user. Massive privacy violation and lawsuit potentially happening there. Far better to use the Claimed Identifier for the OpenID cases, or the service provider-specific user id number in the OAuth cases, as the primary identifier in your user table. Certainly you may capture and display the email address everywhere on the web site where you would display a username so as far as the user knows that's the username -- it's just that internally you use something more precise than that.

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