I'm writing a RESTful Database Server called Phoenix. Being an easy interface into an entire application's data, security is quite an important issue, and I'm interested in what authentication solutions any of you could suggest.
It needs to be:
Secure - it's got to be very hard to break. Signing requests could be a good way of doing this, but considering it's REST there aren't many parameters that are sent so I don't know what good singing would do.
Minimal - I'd rather it didn't take four requests to compare six tokens in HMAC-signed requests - the USP of the server is it's simplicity, so authentication from clients has got to be easy.
Implementable - it has to fit the system, which is a database server. So, for instance, oAuth wouldn't work here.
I'd love to hear your suggestions - thank you!
Jamie
Not much information here about what your security or implementation needs are. The quick answers are Basic or Digest over SSL, or signed requests. Are there reasons not to use these?
Signing requests typically adds a timestamp and/or a nonce, so any request can be authenticated. See the Amazon AWS authentication documentation for a description and libraries.
I have a similar server. I choose to use OAuth signing for its simplicity,
http://oauth.net/core/1.0#signing_process
We don't enforce the nonce, just limit the timestamp to a short window (30 seconds) to thwart replay.
The OAuth library is available on many platforms so you don't have to write much code to implement it. Don't know why you think OAuth is not implementable.
For each client allowed to access the data, it's assigned a consumer_key and a consumer_secret. All the requests are signed with consumer_secret so only client knowing the secret can get access.
We also considered other options. HTTTP Basic Auth over SSL is too expensive. HTTP Digest Auth is too slow because it needs to wait for a challenge.
Related
In short,
We made an app that interacts with a server to fetch some data.
But now we think about security and here is our question :
Can a man in the middle attack happen ? Can someone use something as burpsuite or wireshark to analyze queries that come and go ?
Any suggestions will be greatly appreciated,
thanks.
It depends on who you mean.
If the app uses https to communicate with the server, a 3rd party ("somebody else" other than the user and the server) will not be able to see or modify traffic in a MitM attack. That's why you need https.
However, the user itself (ie. anybody having administrative access to the client) will be able to do so. If the question is about protecting the app from its legitimate users by hiding the traffic in some way, that's not possible. Even if using https, the user of the client device can trust any server certificate, for example the one presented by a proxy like Burp, so they will be able to see and analyze their own traffic.
I make a web service and I'm going to use a React. A data for the service will be fetch from my API.
But there is a simple way to find out which endpoints I'm using, and what data I'm sending. This knowledge gives a lot options to make bots for my service.
Is there any option to prevent this?
I know, I can require a signing all requests, but it's also easy to get to know.
This cannot be done. Whatever is done in client-side JavaScript, can be reverse-engineered and simulated.
Efforts should be focused on preventing API from being abused, i.e. throttling or blacklisting clients based on their activity or available information (user agent, suspicious request, generated traffic). If the use of API allows captcha, suspicious clients can be asked for proving their humaneness.
There are half-measures that can be applied to client side application and make it less advantageous for abuse (and also for development).
Prevent unauthorized access to unminified/unobfuscated JS AND source maps. There may be a need to authorize them on per user basis. This will make debugging and bug reporting more difficult
Hard-code parts that are involved in request signing to browser APIs, e.g.:
apiKey = hash(NOT_SO_SECRET_KEY + document.querySelector('.varyingBlock').innerHTML)
This requires bots to emulate browser environment and makes their work much less efficient. This also affects the design of the application in negative way. Obviously, there will be additional difficulties with SSR and it won't translate to native platforms easily.
here two basic preventive measures that you can use.
Captcha
Use a captcha service like recaptcha. so that user can use your website only after passing the captcha test. Its highly difficult for bots to pass the captchas.
Rate Limit Api usage.
Add rate limiting to your api. so that a logged in user can only make 100 requests in 10 minutes, the numbers will depend on you use case
Contemplating building an Angular 2 front-end to my website. My question is not necessarily related to Angular but I want to provide full context.
Application logic that displays content to user would shift to the client. So on the server side, I would need to expose data via a RESTful JSON feed. What worries me, is that someone can completely bypass my front-end and execute requests to the service with various parameters, effectively scraping my database. I realize some of this is possible by scraping HTML but exposing a service with nicely formatted data is just a no-brainer.
Is there a way to protect the RESTful service from this? In other words, is there a way to ensure such service would only respond to my Angular 2 application call? Authentication certainly isn't a solution here - I don't want to force visitors to authenticate and the scraper could very well authenticate and get access, anyway.
I would recommend JWT Authorization. One such implementation is OAuth. Basically you get a json web token ( JWT ) that has been signed by an authority you trust that tells about the user and what resources they can access on your api.
If the request doesn't include an Authorization token - your API rejects it.
If the token has been tampered with by someone trying to grant themselves privledges after the token is signed by the authorization authority - your API rejects it.
It is a pretty cool piece of kit.
This site has information about OAuth implementations in different languages, hopefully your favorite is listed.
Some light bed time reading.
There is no obvious way to do it that I know of, but a lot of people seem to be looking at Amazon S3 as a model. If you put credentials in your client code, then anyone getting the client code can see them. I might suggest that you could write the server to pass a time limited token back to the browser with the client code. The client code would be required to pass it back to the server for access. This would prevent anyone from writing their own client code, as only client code sent by the server would work, though only for some period of time. The user might occasionally get timeouts, but that depends on how strict you want to make the token timeouts. Of course, even this kind of thing could be hacked by someone making a client request to get a copy of the token to use with their own client API, but at that point you should be proud that someone is trying so hard to use your API! I have not tried to write such a thing, so I don't have any practical experience with the issue. I myself have wondered about it, but also don't have enough experience with this architecture to see what, if anything, others have been doing. What do angularJS forums suggest?
Additional References: Best Practices for securing a REST API / web service
I believe the answer is "No".
You could do some security by obscurity type stuff. Your rest API could expose garbled data and you could have some function that was "hidden" in your code un-garble it. Though obviously this isn't fool proof, but if you expose data on a public site it's out there regardless of server or client rendering.
Ok so recently I have been in need of creating a application with WebRTC for video voice etc.
So after looking into some libraries I found SimpleWebRTC to be pretty handly looking:
https://github.com/andyet/SimpleWebRTC
So what I am interested in is how do I implement a STUN/TURN server? (Would be great if someone could explain the differences in plain English!) And also is there a authentication mechanism. At the moment my app contacts my database and logins in user etc, but the stun and turn server would be private and not in any way involved in the authentication procedure.
So basically:
What is the best way to implement STUN/TURN
Is there any authentication mechanism?
Note, this is for a hybrid app so I will be using JavaScript/AngularJS for this. The main reason why I chose SimpleWebRTC.
Thank you!
I suggest you use an existing STUN or TURN server like coturn.
STUN servers are very lightweight and often left without authentication. A STUN server basically tells a client what its IP address appears to be, which is necessary to make peer connections across NAT (network address translation) boundaries.
TURN servers are very resource intensive because they relay media; all of the media for a call can go through the TURN server, so it's important to secure TURN. You use TURN servers in situations where UDP may be blocked, or for particular kinds of NATs that cause problems.
The authentication for coturn's TURN server can take one of two forms:
Simple (username, password) pair
TURN REST API. This uses a secret between the TURN server and another entity. The entity issues tokens with expiration times, and the TURN server verifies the token has not expired and was issued with knowledge of the shared secret. This is passed by the TURN client as a username, password pair in a format described in the documentation.
I've read quite a few SO threads about authentication and authorization with REST and Angular, but I'm still not feeling like I have a great solution for what I'm hoping to do. For some background, I'm planning to building an app in AngularJS where I want to support:
Limited guest access
Role-based access to the application once authenticated
Authentication via APIs
All of the calls to the REST API will be required to occur over SSL. I'd like to do build the app without breaking RESTful principles, namely not keeping session state stored on the server. Of course, whatever is done vis-a-vis authorization on the client-side has to be reinforced on the server side. Since we need to pass the entire state with each request, I know I need to pass some sort of token so that the backend server receiving the REST request can both authenticate and authorize the call.
With that said, my main question is around authentication - what are the best practices here? It seems there are lots of different approaches discussed, here's just a few that I've found:
http://broadcast.oreilly.com/2009/12/principles-for-standardized-rest-authentication.html
http://frederiknakstad.com/2013/01/21/authentication-in-single-page-applications-with-angular-js/
http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html
There was a similar question asked (AngularJS best practice application authentication), but unless I'm misunderstanding the answer, it seems to imply that a server session should be used, which is breaking RESTful principles.
My main concern with the Amazon AWS and the George Reese article is it seems to assume that the consumer is a program, rather than an end user. A shared secret can be issued to a programmer in advance, who can then use it to encode calls here. This isn't the case here - I need to call the REST API from the app on behalf of the user.
Would this approach be enough? Let's say I have a session resource:
POST /api/session
Create a new session for a user
To create a session, you need to POST a JSON object containing the "username" and "password".
{
"email" : "austen#example.com",
"password" : "password"
}
Curl Example
curl -v -X POST --data '{"username":"austen#example.com","password":"password"}' "https://app.example.com/api/session" --header "Content-Type:application/json"
Response
HTTP/1.1 201 Created {
"session": {
"id":"520138ccfa4634be08000000",
"expires":"2014-03-20T17:56:28+0000"
}
}
Status Codes
201 - Created, new session established
400 - Bad Request, the JSON object is not valid or required information is missing
401 - Unauthorized, Check email/password combo
403 - Access Denied, disabled account or license invalid
I'm leaving out the HATEOAS details for clarity. On the backend, there would be a new, limited duration session key created and associated with the user. On subsequent requests, I could pass this as part of the HTTP headers:
Authorization: MyScheme 520138ccfa4634be08000000
Then the backend servers would be responsible for digesting this out of the request, finding the associated user and enforcing authorization rules for the request. It should probably update the expiration for the session as well.
If all this is happening over SSL, am I leaving the door open to any kind of attacks that I should be protecting against? You could try to guess session keys and place them in the header, so I suppose I could additionally append a user GUID to the session key to further prevent brute force attacks.
It's been a few years since I've actively programmed and I'm just getting back into the swing here. Apologies if I'm being obtuse or unnecessarily reinventing the wheel, just hoping to run my ideas by the community here based on my reading thus far and see if they pass the litmus test.
When someone asks about REST authentication, I defer to the Amazon Web Services and basically suggest "do that". Why? Because, from a "wisdom of the crowds" point of view, AWS solves the problem, is heavily used, heavily analyzed, and vetted by people that know and care far more than most about what makes a secure request than most. And security is a good place to "not reinvent the wheel". In terms of "shoulders to stand on", you can do worse than AWS.
Now, AWS does not use a token technique, rather it uses a secure hash based on shared secrets and the payload. It is arguably a more complicated implementation (with all of its normalization processes, etc.).
But it works.
The downside is that it requires your application to retain the persons shared secret (i.e. the password), and it also requires the server to have access to that a plain text version of the password. That typically means that the password is stored encrypted, and it then decrypted as appropriate. And that invite yet more complexity of key management and other things on the server side vs secure hashing technique.
The biggest issue, of course, with any token passing technique is Man in the Middle attacks, and replay attacks. SSL mitigates these mostly, naturally.
Of course, you should also consider the OAuth family, which have their own issues, notably with interoperability, but if that's not a primary goal, then the techniques are certainly valid.
For you application, the token lease is not a big deal. Your application will still need to operate within the time frame of the lease, or be able to renew it. In order to do that it will need to either retain the user credential or re-prompt them for it. Just treat the token as a first class resource, like anything else. If practical, try and associate some other information with the request and bundle it in to the token (browser signature, IP address), just to enforce some locality.
You are still open to (potential) replay problems, where the same request can be sent twice. With a typical hash implementation, a timestamp is part of the signature which can bracket the life span of the request. That's solved differently in this case. For example, each request can be sent with a serial ID or a GUID and you can record that the request has already been played to prevent it from happening again. Different techniques for that.
Here is an incredible article about authentication and login services built with angular.
https://medium.com/opinionated-angularjs/7bbf0346acec
This SO question do a good job of summing up my understanding of REST
Do sessions really violate RESTfulness?
If you store a token in a session you are still creating state on the server side (this is an issue since that session is typically only stored on the one server, this can be mitigated with sticky sessions or other solutions).
I'd like to know what your reasoning is for creating a RESTful service though because perhaps this isn't really a large concern.
If you send a token in the body along with every request (since everything is encrypted with SSL this is okay) then you can have any number of servers (load balanced) servicing the request without any previously knowledge of state.
Long story short I think aiming for RESTful implementations is a good goal but being purely stateless certainly creates an extra layer of complexity when it comes to authentication and verifying authorization.
Thus far I've started building my back-ends with REST in mind, making URIs that make sense and using the correct HTTP verbs, but still use a token in a session for the simplicity of authentication (when not using multiple servers).
I read through the links you posted, the AngularJS one seems to focus just on the client and doesn't seem to explicitly address the server in that article, he does link to another one (I'm not a Node user so forgive me if my interpretation is wrong here) but it appears the server is relying on the client to tell it what level of authorization it has which is clearly not a good idea.