User's locale in microservice - JHipster - java

In one of the microservices, in a JHipster microservice architecture, I want to generate a document, in the users' language.
In the gateway, the users' language is retrieved by a cookie (AngularCookieLocaleResolver). But when a request, routed through the gateway, arrives at the microservice, no cookies are found on the request.
I see a few options here:
Add a locale claim to the JWT-token
Contact the gateway with the username, to retrieve the locale
Do not generate locale specific content at a microservice
I would prefer the first option, but maybe there are some better options...
Can anyone help me choose or list up alternatives?

First option using JWT claim makes sense and it could be proposed as an enhancement request to JHipster project. I can see one minor drawback: any user changing her locale won't get correct localised content until token expires or she logs out and re-authenticates.
An alternative would be to pass the locale as a parameter of your resources requests, this makes sense as client is supposed to know it and also in a broader scope client could a be a partner application using another kind of authentication like an API key.

Related

How Should I Add Authorisation In My REST API If I Use Azure APIM?

I am planning on hosting my REST API in a VM in a VNET where the only point of entry is via Azure API Management.
I have multiple back ends so the API Management will route to a different backend base url depending on the group the user is in and the backend will also return different data depending on the user making the call.
Since the Azure API Management can handle authorisation, JWT validation and setting headers etc what type of authorisation code should I put in my REST API application?
Should I try to validate the JWT again in my Java code or just parse the headers?
i.e. is it safe to code it as a public API and trust that the headers have been set correctly by API Management?
Or should I make a call to Azure Active Directory from the Spring controller every time to validate that the user does actually exist in the specified group and that the group specified is the one expected for this backend?
If so, how would I do that from Java and how would I inject an offline version when running locally?
Since your API will be inside a VNET it'll be protected as it is. But, there is really no reason to just have it open. The more layers of protection you can add the better your chances to whistand a potential attack.
So see whatever is most convenient to you. You can rely on APIM doing user authentication and authorization and avoid doing that in your backend API. But it would be a good idea to check if call made to your backend API is coming from APIM, and you can do that by sending credentials from APIM. The best option here would be client certificates: https://learn.microsoft.com/en-us/azure/api-management/api-management-howto-mutual-certificates
But you can also send basic credentials: https://learn.microsoft.com/en-us/azure/api-management/api-management-authentication-policies#Basic

Exposing a web site through web services

I know what I am asking is somehow weird. There is a web application (which we don't have access to its source code), and we want to expose a few of its features as web services.
I was thinking to use something like Selenium WebDriver, so I simulate web clicks on the application according to the web service request.
I want to know whether this is a better solution or pattern to do this.
I shall mention that the application is written using Java, Spring MVC (it is not SPA) and Spring Security. And there is a CAS server providing SSO.
There are multiple ways to implement it. In my opinion Selenium/PhantomJS is not the best option as if the web is properly designed, you can interact with it only using the provided HTML or even some API rather than needing all the CSS, and execute the javascript async requests. As your page is not SPA it's quite likely that an "API" already exists in form of GET/POST requests and you might be lucky enough that there's no CSRF protection.
First of all, you need to solve the authentication against the CAS. There are multiple types of authentication in oAuth, but you should get an API token that enables you access to the application. This token should be added in form of HTTP Header or Cookie in every single request. Ideally this token shouldn't expire, otherwise you'll need to implement a re-authentication logic in your app.
Once the authentication part is resolved, you'll need quite a lot of patience, open the target website with the web inspector of your preferred web browser and go to the Network panel and execute the actions that you want to run programmatically. There you'll find your request with all the headers and content and the response.
That's what you need to code. There are plenty of libraries to achieve that in Java. You can have a look at Jsop if you need to parse HTML, but to run plain GET/POST requests, go for RestTemplate (in Spring) or JAX-RS/Jersey 2 Client.
You might consider implementing a cache layer to increase performance if the result of the query is maintained over the time, or you can assume that in, let's say 5 minutes, the response will be the same to the same query.
You can create your app in your favourite language/framework. I'd recommend to start with SpringBoot + MVC + DevTools. That'd contain all you need + Jsoup if you need to parse some HTML. Later on you can add the cache provider if needed.
We do something similar to access web banking on behalf of a user, scrape his account data and obtain a credit score. In most cases, we have managed to reverse-engineer mobile apps and sniff traffic to use undocumented APIs. In others, we have to fall back to web scraping.
You can have two other types of applications to scrape:
Data is essentially the same for any user, like product listings in Amazon
Data is specific to each user, like in a banking app.
In the firs case, you could have your scraper running and populating a local database and use your local data to provide the web service. In the later case, you cannot do that and you need to scrape the site on user's request.
I understand from your explanation that you are in this later case.
When web scraping you can find really difficult web apps:
Some may require you to send data from previous requests to the next
Others render most data on the client with JavaScript
If any of these two is your case, Selenium will make your implementation easier though not performant.
Implementing the first without selenium will require you to do lots of trial an error to get the thing working because you will be simulating the requests and you will need to know what data is expected from the client. Whereas if you use selenium you will be executing the same interactions that you do with the browser and hence sending the expected data.
Implementing the second case requires your scraper to support JavaScript. AFAIK best support is provided by selenium. HtmlUnit claims to provide fair support, and I think JSoup provides no support to JavaScript.
Finally, if your solution takes too much time you can mitigate the problem providing your web service with a notification mechanism, similar to Webhooks or Resthooks:
A client of your web service would make a request for data providing a URI they would like to get notified when the results are ready.
Your service would respond immediatly with an id of the request and start scraping the necessary info in the background.
If you use skinny payload model, when the scraping is done, you store the response in your data store with an id identifying the original request. This response will be exposed as a resource.
You would execute an HTTPPOST on the URI provided by the client. In the body of the request you would add the URI of the response resource.
The client can now GET the response resource and because the request and response have the same id, the client can correlate both.
Selenium isn't a best way to consume webservices. Selenium is preferably an automation tool largely used for testing the applications.
Assuming the services are already developed, the first thing we need to do is authenticate user request.
This can be done by adding a HttpHeader with key as "Authorization" and value as "Basic "+ Base64Encode(username+":"+password)
If the user is valid (Users login credentials match with credentials in server) then generate a unique token, store the token in server by mapping with the user Id and
set the same token in the response header or create a cookie containing token.
By doing this we can avoid validating credentials for the following requests form the same user by just looking for the token in the response header or cookie.
If the services are designed to chcek login every time the "Authorization" header needs to be set in request every time when the request is made.
I think it is a lot of overhead using a webdriver but it depends on what you really want to achieve. With the info you provided I would rather go with a restTemplate implementation sending the appropriate http messages to the existing webapp, wrap it with a nice #service layer and build your web service (rest or soap) on top of it.
The authentication is a matter of configuration, you can pack this in a microservice with #EnableOAuth2Sso and your restTemplate bean, thanks to spring boot, will handle the underlining auth part for you.
May be overkill..... But RPA? http://windowsitpro.com/scripting/review-automation-anywhere-enterprise

architectural challenges in authenticating and authorizing users against shared web services

My current system architecture for a web application looks like above. Essentially, its just one code base, that is being deployed in different contexts, so for instance, app1.localhost.com, app2.localhost.com.
These are my current challenges -
I need query my webservices using ajax calls from user browser. But, somehow I need to tell the webservices, that the request is coming from user1 for app1 or user2 or app2. Accordingly, the webservice can go query the right schema in the database and return the results.
My webservices need to be stateless.
I cannot have the user tamper with the request from the browser.
Is this a flawed model? Are my expectations out of standard way of doing this? What is the best way to realize this architecture?
Let's go through this step by step.
So your webservice needs to know the application and the user.
Easy: just include it in the request as a parameter or as part of the url.
Same goes for some information possibly provided by the user.
The challenge comes with the requirement that the user must not be able to change the request.
This is typically achived by cryptographic signing the request (or the sensitive parts). I kind of assume that replay attacks are also an issue.
Create a certificate for the apps.
On the application server create a nonce.
Sign the nonce, the application name and the user name using the certificate.
Include nonce, servername, username and signature in the request used for the ajax call.
Check nonce, servername, username and signature match in the webservice
Check also that the nonce wasn't used before.
Checking the nonce does require some state, but just a list of nonces. If you make the nonces increasing you can even discard any nonces much smaller than the last one you received, limiting the amount of state even more.
You should check if something like this exists as a ready made protocol, because it is always a bad idea to create your own security relevant protocols.

Securing a stateful web service

We are planning on developing a layer of REST services to expose services hosted on a legacy system. These services will be used by a classic web application and native mobile phone applications.
This legacy system is secured in such a way that an initial username + password authentication is required (a process that can take 5 to 10 seconds). After the initial authentication, a time-constrained token is returned. This token must then be included in all further requests or else requests will be rejected.
Due to a security requirement, the legacy security token cannot be returned outside of the REST service layer. This means that the REST service layer needs to keep this token in some form of user session, or else the expensive username + password authentication process would need to be repeated for every call to the legacy system.
The REST service layer will be implemented using a Java 6 + Spring 3 + Spring Security 3 stack. At first sight, it looks like this setup will run fine: Spring-based REST services will be secured using a rather standard Spring Security configuration, the legacy security token will be stored in the user's HTTP session and every call will retrieve this token using the user's session and send it to the legacy system.
But there lies the question: how will REST clients send the necessary data so that the user's HTTP session is retrieved properly? This is normally done transparently by the web browser using the JSESSIONID cookie, but no browser is involved in this process. Sure, REST clients could add cookie management to their code, but is this an easy task for all Spring RestTemplate, iPhone, BlackBerry and Android clients?
The alternative would be to bypass the HTTP session at the REST service layer and use some other form of user session, maybe using a database, that would be identified using some key that would be sent by REST clients through a HTTP header or simple request query. The question then becomes, how can Spring Security be configured to use this alternative session mechanism instead of the standard Servlet HttpSession?
Surely I am not the first dealing with this situation. What am I missing?
Thanks!
There's nothing magical about cookies. They're just strings in HTTP headers. Any decent client API can handle them, although many require explicit configuration to enable cookie processing.
An alternative to using cookies is to put the JSESSIONID into the URL. I don't know anything about spring-security, but it seems that that's actually the default for at least some types of URL requests, unless disable-url-rewriting is explicitly set to true . This can be considered a security weakness, though.
Unfortunately authentication is highly problematic -- a bit of a blind spot in terms of web standards and browser implementations. You are right that cookies are not considered "RESTful" but purists, but even on fully-featured browsers avoiding takes quite a bit of hackery, as described in this article: Rest based authentication.
Unfortunately I haven't done any mobile development, so I can't suggest what the best compromise is. You might want to start by checking what authentication models each of your targetted platforms does support. In particular, two main options are:
HTTP authentication (ideally "digest", not "basic")
Cookies
One possibility would be to provide both options. Obviously not ideal from a technical or security point of view, but could have merits in terms of usability.

Single Sign On without cookies in Java

I keep on facing this question from my manager how SSO will work if client disable cookies but I don't have any answer. We are currently using JOSSO for single sign on. Do we have any open source framework which support single sign on without using cooking mechanism.
In the absence of cookies, you're going to have to embed some parameter in each url request. e.g. after logging in you assign some arbitrary id to a user and embed that in every link such as http://mydomain.com/main?sessionid=123422234235235. It could get pretty messy since every link would have to be fixed up before it went out the door which slows down your content. It also has security, logging and session history implications which are not such a huge deal when the state is in a cookie.
It may be simpler to do a simple cookie test on logged in users and send them off to an error page if they do not have cookies enabled.
The CAS project passes a "ticket" from the sign on server to the consuming application as a url query parameter, the consuming app then makes a back channel request back to the sign on server to validate the ticket's authenticity. This negates the need for cookies and therefore works across domains however it is a bit "chatty"
Another arguably more robust solution is to use a product based on SAML which is an industry standard for cross domain single sign on. There are a couple of open source products out there which use SAML and CAS itself has a SAML extension however they are typically quite complex to setup. Cloudseal is also based on SAML and is much simpler to use. The Cloudseal platform itself is delivered as a managed service but all the client libraries are open source
Of course with all these solutions you are simply passing a security context from one server to another, the consuming application will no doubt create it's own local session so you would then need to use URL rewriting instead of cookies
Disclaimer: I work for Cloudseal :)

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