I am going to offer a web API service that allows users to download and "rent" content for a monthly subscription fee. The API will either be open to everyone or possibly just select parties (not sure yet). Each developer must agree to a license, and they receive a developer key for their person. Each software application will have its own key as well. So then end-users will download the software which will interact with my service's API. Each user will have a key for each application as well (probably using OAuth).
Content will be cached on first download and accessible offline via just the third-party application that cached the content.
If a user cancels their subscription, I plan on doing the following:
Deactivate the user's OAuth key for all applications.
Do not allow the user's account to download new content via the API (and subsequently any software that uses the API).
Now, the big question is: how do I make content expire if they cancel their subscription? If they cancel, they should not have access to content anymore. Here are ideas I've thought of (some of these are half-solutions, not yet fully fleshed out):
Require that applications encrypt downloaded content using the user's OAuth key, making it available to only the application. This will prevent most users from going to the cache directory and just copying and keeping files.
Update the user's key once a month, forcing content to re-cache on a monthly basic. Users could then access content for a month after they cancel their subscription.
Require applications to "phone home" [to the service] periodically and check whether the user's subscription has terminated. If so, require in the API developer license that applications expire cache. If it is found that applications do not comply, their keys (and possibly keys for all developers) are permanently deactivated as a consequence.
One major worry is that some applications may blatantly ignore constraints of the license. Is it generally acceptable to rely on applications abiding by the licensing constraints? Bad idea?
Any other ideas? Maybe a way to make content auto-expire after x days? Something else? I'm open to out-of-the-box ideas.
If you want to control the usage of content, you need to be in control of the access point. Most applications that implement this scheme ship a server or client product that provides access to the content.
I'm assuming your architecture is returning data, pure and simple. If I'm a developer using your web service, what is to prevent me from caching all the responses in static files elsewhere at query time? Nothing, because your access point is your web server. You have no control over my usage of the content once it departs from the access point.
Unless the downloaded content requires a callback to your server when being consumed, you're out of luck with this strategy.
Related
I recently visited "AWS Free Tier". Under that in "serverless" option is "AWS Lambda". I am trying to develop an application. I want to know what will be the best resource to use.
USAGE: I need to connect to server through mobile app using HTTP POST. 1st it will register the bus number. Then it will add the corresponding bus stops and the fare between each bus stop. The app will next time send bus number and get all bus stops. Then it will select 2 bus stops and send to server. It will pay the required fare. Server will generate the bus ticket and store in database. It will send 1 copy to the mobile.
I need an web server for development and testing purpose. I had started with JSP. But due to some reasons I was not able to access the JSP page through android app. However I was able to access the JSP through browser. In android app, I can access other websites. I think the url was the problem. So, I decided to use AWS server. Please let me know where I can use JSP. If you have any other server and database, please let me know. Currently I will be using it for development and testing purpose. So, 1-5 users may use it. But later I will run it as a business. Then more users will be using it. (So, please let me know about the payments for business use also, if you have idea about that) I will need database also.
You could write a service which recieves an HTTP request and accesses a database as part of the logic it performs to generate a response and host that service with AWS Lambda.
You would need a database in addition to AWS Lambda (there are many database services available from AWS and other providers).
You can't just drop your JSP files onto Lambda. It does not support JSP (although it does support programs written in Java).
I am working on a cross platform app that will be created using C++-> mobile devices, and using Perl-> Desktop PCs (like Windows /Linux/Mac OS).
Now, since the app will be downloadable, I have concerns regarding the ability of hackers to obtain the source code of my app.
Specifically, the app will connect to my central database-- at the minimum, I want that hackers are not able to obtain my database connection details. Ideally, I would want no part of the code to be hacked.
Basically, the user can update some of his information using this app-- if hackers get hold of this data they can easily change any unfortunate user's data. One thing that I have thought of is that the user will have to initially authenticate with OAuth/OAuth2 ( using his email ID #yahoo/#hotmail/#gmail)-- and only after that the app will actually show the admin interface. But at any rate, at some point the app will connect to the central database-- which is why I dont want the database's access details to be compromised.
Many organisations make such apps, so they must be facing this type of problem themself? I would like to know how I can protect my app (ideally entire code), and atleast the db credentials.
The simple answer is you do not expose your database. Ever.
Add a service layer (could be HTTP-based but doesn't have to be) on top that will deal with authentication and authorisation. Your app then logs in using the user's credentials and acts on their behalf. Your service layer exposes an API which your application talks to, but your service makes and controls all calls to the DB.
You already mention OAuth - that's a perfectly acceptable way of adding authentication to such an API.
You cannot.
On the bright side you can put security on your server. The connecting client provides credentials that they are a given user. The server generates the SQL command after proving the request is allowed. Backers can do anything your app can do, but your app becomes incapable of behaving badly to your database.
The previous answers are absolutely correct. You want a server based service layer that provides the authentication/authorization code and interacts with the database. However, it isn't always a perfect world and if you are stuck with the requirement that these applications must act as a database client you want to limit the exposure as much as possible. Typically this is done by having the client use a specific account which has not been granted any access to the general database. You then create specific stored procedures that can only do the operations and queries that are required of the application. This prevents anyone finding the credentials in the code from doing anything in the database that isn't intended, but you still have the problem that anyone can impersonate someone else by reviewing the code. There isn't a way to prevent that without a server side component. This might be okay for a closed/trusted group of users, but I wouldn't release anything to the general public with this method.
If you can do it, use OAuth2 and allow a trusted third party handle authentication. Twitter, Facebook and GitHub are all relatively paranoid about security; and the other poster is correct: never expose direct db access as part of the app the user has access to; put it behind a service of its own.
Good luck! :)
I work for a company that develops a software product that processes bank transactions and gives the user insight into his/her spending. Our customers (usually banks) integrate the product into their online banks.
I have a question about securing the communication between the online bank, and our system. Before I ask the question, I want to give you some background.
The bank will usually install our system on a set of servers in their hosting environment.
We offer a number of ways to integrate:
Web services - In this case the bank will make calls to a set of REST services on the server, and then generate a webpage with the results (on the server side).
Iframes - In this case the bank will embed iframes in their online bank webpages. The iframes contain webpages rendered directly from our web application.
Inline widgets - In this case the bank will embed JavaScript references on their pages. When the document loads, the JavaScript widgets will render themselves, using AJAX calls. They communicate with a proxy on the bank server, which in turn communicates with our webapp.
We currently have a custom solution where we generate and sign security tokens for the users, and pass these with the requests.
But as banks have very strict security policies, they would feel better with us using a known and trusted security protocol for the communication. It is a big concern, which we want to address.
So the question is, which protocol is best suited for the integration use cases I listed above? There is a plethora of single-sign-on standards out there, and solutions like SAML, oauth, etc. I get the feeling that these solutions might be an overkill for my situation.
I want to find a solution that is simple. As the servers will run side by side in the same hosting environment, and trust each other completely, there is no need for the end user to authorize one or the other (or being redirected between, clicking buttons to give access to the app).
That is, the security protocol should not require any intervention from the end user. The end user simply logs into his/her online bank, and via secure communication has access to the data from our web server.
So...any suggestions?
Thanks a lot!
OGG
After some deliberation, we decided to use 2-legged OAuth (online bank uses consumer key and consumer secret to sign requests to our app).
OAuth signature can either be put in a request header, or request parameters. It nicely solves our problem, as the REST requests can be signed, and the IFRAME src URL-s can also be signed (all communication is over HTTPS).
For those interested, a couple of references:
This article shows using OAuth with IFRAMEs: http://developer.tradeshift.com/blog/cross-site-user-verification/
This article mentiones some security issues with OAuth, and how threats can countered: http://software-security.sans.org/blog/2011/03/07/oauth-authorization-attacks-secure-implementation
Several web service APIs have you sign up for an API key. For example, UPS Web services requires a key, which is included in calls to their service -- In addition to the username and password.
What is this key used for by the provider? Perhaps UPS is the only one to require both API key and username/password?
One idea is that they use it to limit or measure API usage, but it seems to me that a setting in the users profile could easily do the same thing -- especially since you generally have to get an account w/ username and password to get the API in the first place.
There are two predominant use cases. The first is to measure, track and restrict API usage. If someone is building a service that allows third parties to access it, the service provider may want to control (or at least know) who has access so that they can try and prevent things like denial of service attacks. On the measure and track side, interesting information can be obtained such as knowing which applications are popular for accessing the service or which features people use the most.
The other use case is related to security and authentication. It is unwise for a service provider to have third party applications and services require users to give up their username and password for the primary service. This is a huge exposure. That is why many services are standardizing on protocols such as OAuth, which provides delegated access via authorization to a user's data. While not foolproof, it is definitely preferable to distributing user credentials to unknown, and untrusted, parties.
Most of the time it is to monitor how developers are using the web-api. If they somehow disagree with your usage of the api it provides a means for them to shut it/you down without hurting the other users. And the statistics per user/app are always valuable.
I've used the flickr api - in that situation the key is yours, but the login data might be those of people using your app, so the api key is the only way to differentiate between the apps.
Usually it used to get stats on how much application performing queries to API.
I think asking username/password with API key is ambigious in some cases, but it is a way how it is implemented - so we can't do something with it.
They ask for API key because you could have more than one API under same account - in case you have more than one site which are use same API.
They could use it to signify which version of the API you are trying to use. Perhaps in Version 1.0, there is a method that takes a POST on www.UPS.com/search and there is another one in version 2.0 at the same address, but takes a different parameter set, or even returns data in a different format/style. Your program was built on V1.0 and expects a certain API contract. They want to be able to create V2.0 without interfering with their customer's products.
That's just a guess, but it sounds good to me.
I think Gracenote does a similar thing for cddb. I forget the details, but I remember something about some token.
(They have/had really draconian rules about using their service too.)
Simon reminded me what the gracenote thing was. Gracenote and Fedex and other webservices have lots of developers writing apps for the software. So the developers get a token to put into their apps, but the end users have their own user name and password. It lets the services keep an eye on abusing programs, etc. That is probably te primary reason. (like a browser or a webbot informing the webserver who/what it is)
Originally, Blogger required you to apply for an API key (a la Google Maps) and used it to restrict access to the API. As Blogger evolved into Metaweblog, the requirement for the API became less important, and Blogger no longer requires you to apply for a key. As noted by others, it can still be used for tracking purposes.
In our situation, our clients want it for:
Tracking/analytics - figuring out who's doing what and building what products. Because a number of users are desktop apps, just looking at referrers isn't always enough.
Permissions - which resources should a user have access to? How can a user build apps that have access to specified resources?
Licensing/legal - enforcing that users have read and accepted ToU/licensing information.
Security - passing around usernames/passwords is a really bad idea.
We don't exactly comply with the XML-RPC spec, but the concepts are nearly identical. A client comes in over HTTP/HTTPS with an XML payload. We respond with an XML payload answering the request. This is primarily machine to machine, so no human to type a username/password. Our construct runs within apache tomcat. We would like to authenticate the request and since not every service is available to every client, we need to authorize the request as well. We have both subscription and per use charging models so it is necessary to log everything.
What would you recommend for both server and client?
HTTP BASIC/DIGEST works fine for most machine to machine tasks, and it handled by the server so your API is unaffected.
It doesn't work as well for interactive uses because it's difficult to "log out" the user without closing the browser.
Otherwise you'll most likely need to alter your APIs to include authentication information and have your methods authenticate that within your code.
Or you could use the classic "login", set a cookie, keep a session technique.
But, frankly, for machine to machine work, HTTP BASIC is the easiest.
edit, regarding comments.
HTTP BASIC is simply a protocol used to present the artifacts necessary for authentication, and it works well for machine to machine web services.
HOW IT IS IMPLEMENTED is dependent on you and your application. Using Java, you can use container authentication and that will provide authentication as well as role mapping. The user -> role mapping is handled in either a data file or database. The URLs protected, and what roles are valid for each URL, is managed by web.xml.
If you continue to add different roles to different URLs, then, yes, you'll need to redeploy that application.
However, if you're just adding new users, then you simply update your file or database. And if you're adding new logic, and this new URLs, then you have to redeploy anyway. If you have a ROLE structure with a fine enough granularity, you won't have to be messing with the web.xml until you actually add new methods. For example you could, at the extreme, create a role per method, and assign them individually to users. Most don't need to go that far.
If you don't want to use container authentication, then write a Servlet Filter to implement your vision of mapping user and roles to URLs. You can still use the HTTP BASIC protocol for your clients, even if you implement your own facility.
If you're looking for an overall generic Java security framework, I defer to google -- there are several, I've not used any of them. I've had good luck with container authentication and writing our own.
#Will
I second the HTTP Basic suggestion, and can testify that it integrates fairly well with Spring Security, which I implemented on top of a legacy application that rolled its own DB-based authentication/authorization logic.