Securing REST services in Jersey - java

I am very much new to web services. I have exposed some REST services using Jersey 2 in integration with Spring. Now I need to secure those rest services using authentication with username/password. I am told not to use Spring Security.
I have no idea of how to do this. I did search on the net but various links show various implementation and I am unable to decide how to proceed with it.

A common way for authenticating with username and password is to use Basic Authentication. Basically the client needs to send a request header Authorization, with the the header value as Basic Base64Encoded(username:password). So is my username is peeskillet and my password is pass, I, as a client, should set the header as
Authorization: Basic cGVlc2tpbGxldDpwYXNz
In a servlet environment, the container should have support for Basic authentication. You would configure this support on the web.xml. You can see an example in 48.2 Securing Web Applications of the Java EE tutorial. You will also notice in an example
<transport-guarantee>CONFIDENTIAL</transport-guarantee>
That is for SSL support. This is recommended for Basic Authentication.
If you don't want to deal with the hassle of working with security domains and login modules, realm, and such, that would be required to customize the servlet support, or if you're just not in a servlet environment, implementing Basic Auth in a ContainerRequestFilter is really not too difficult.
You can see a complete example of how this could be done at jersey/examples/https-clientserver-grizzly. You should focus on the SecurityFilter
The basic flow in the filter goes something like this
Get the Authorization header. If it doesn't exist, throw an AuthenticationException. In which case the AuthenticationExceptionMapper will send out the header "WWW-Authenticate", "Basic realm=\"" + e.getRealm() + "\", which is part of the Basic Auth protocol
Once we have the header, we parse it just to get the Base64 encoded username:password. Then we decode it, then split it, then separate the user name and password. If any of this process fails, again throw the WebApplicationException that maps to a 400 Bad Request.
Check the username and password. The example source code just checks if the username is user and the password is password, but you will want to use some service in the filter to verify this information. If either of these fail, throw an AuthenticationException
If all goes well, a User is created from the authenticate method, and is injected into an Authorizer (which is a SecurityContext). In JAX-RS, the SecurityContext is normally used for authorization`.
For the authorization, if you want to secure certain areas for certain resources, you can use the #RolesAllowed annotation for your classes or methods. Jersey has support for this annotation, by registering the RolesAllowedDynamicFeature.
What happens under the hood is that the SecurityContext will be obtained from the request. With the example I linked to, you can see the Authorizer, it has an overridden method isUserInRole. This method will be called to check against the value(s) in #RolesAllowed({"ADMIN"}). So when you create the SecurityContext, you should make sure to include on the overridden method, the roles of the user.
For testing, you can simply use a browser. If everything is set up correctly, when you try and access the resource, you should see (in Firefox) a dialog as seen in this post. If you use cURL, you could do
C:/>curl -v -u username:password http://localhost:8080/blah/resource
This will send out a Basic Authenticated request. Because of the -v switch, you should see all the headers involved. If you just want to test with the client API, you can see here how to set it up. In any of the three cases mentioned, the Base64 encoding will be done for you, so you don't have to worry about it.
As for the SSL, you should look into the documentation of your container for information about how to set it up.

So this is really a matter what you would like to achieve. My case was to get this thing running with mobile and a One-Page-App JavaScript.
Basically all you need to do is generate some kind of header that value that will be needed in every consecutive request you client will make.
So you do a endpoint in which you wait for a post with user/password:
#Path("/login")
public class AuthenticationResource {
#POST
#Consumes("application/json")
public Response authenticate(Credentials credential) {
boolean canBeLoggedIn = (...check in your DB or anywher you need to)
if (canBeLoggedIn) {
UUID uuid = UUID.randomUUID();
Token token = new Token();
token.setToken(uuid.toString());
//save your token with associated with user
(...)
return Response.ok(token).type(MediaType.APPLICATION_JSON_TYPE).build();
} else {
return Response.status(Response.Status.UNAUTHORIZED).build();
}
}
}
Now you need to secure resource with need for that token:
#Path("/payment")
#AuthorizedWithToken
public class Payments {
#GET
#Produces("application/json")
public Response sync() {
(...)
}
}
Notice the #AuthorizedWithToken annotation. This annotaation you can create on your own using special meta annotation #NameBinding
#NameBinding
#Target({ElementType.METHOD, ElementType.TYPE})
#Retention(RetentionPolicy.RUNTIME)
public #interface AuthorizedWithToken {}
And now for the filter that implements checking of the header:
#AuthorizedWithToken
#Provider
public class XAuthTokenFilter implements ContainerRequestFilter {
private static String X_Auth_Token = "X-Auth-Token";
#Override
public void filter(ContainerRequestContext crc) throws IOException {
String headerValue = crc.getHeaderString(X_Auth_Token);
if (headerValue == null) {
crc.abortWith(Response.status(Response.Status.FORBIDDEN).entity("Missing " + X_Auth_Token + " value").build());
return;
}
if(! TOKEN_FOUND_IN_DB) {
crc.abortWith(Response.status(Response.Status.UNAUTHORIZED).entity("Wrong " + X_Auth_Token + " value").build());
return;
}
}
}
You can create any number of your own annotations checking for various things in the http request and mix them. However you need to pay attention to Priorities but that actually easy thing to find. This method needs using https but that is obvious.

Security comes in two main flavours :
Container Based
application based
the standard way to secure spring applications is to use Spring Security (formerly Acegi).
It would be interesting to know why you're not being allowed to use that.
You could use container based security, but I'm guessing that your use of spring precludes that option too.
Since the choice of Spring is usually to obviate the need for the use of a full J2EE container (Edit : though as pointed out below by others, most ordinary servlet containers do allow you to implement various container based security methods)
This really only leaves you with one option which is to roll your own security.
Your use of Jersey suggests that this might be a REST application.
In which case you really ought to stick with standard HTTP Authentication methods that
comes in the following flavours in reverse order of strength :
BASIC
Digest
Form
Certificate
REST applications are usually supposed to be 'stateless', which essentially rules out form based authentication (because you'd require the use of Session)
leaving you with BASIC, Digest and Certificate.
Your next question is, who am I authenticating. If you can expect to know the username AND the password of the user based on what URL they requested (say if it's one set of credentials for all users) then Digest is the best bet since the password is never sent, only a hash.
If you cannot know the Password (because you ask a third party system to validate it etc.) then you are stuck with BASIC.
But you can enhance the security of BASIC by using SSL, or better yet, combining BASIC with client certificate authentication.
In fact BASIC authentication over HTTPS is the standard technique for securing most REST applications.
You can easily implement a Servlet Filter that looks for the Authentication Header and validates the credentials yourself.
There are many examples of such filters, it's a single self contained class file.
If no credentials are found the filter returns 401 passing a prompt for basic auth in the response headers.
If the credentials are invalid you return 403.
App security is almost an entire career in itself, but I hope this helps.

As the former posts say, you could go with different options, with a varying overhead for implementation. From a practical view, if you're going to start with this and are looking for a comfortable way for a simple implementation, I'd recommend container-based option using BASIC authentication.
If you use tomcat, you can setup a realm, which is relatively simple to implement. You could use JDBCRealm, which gets you a user and password from specified columns in your database, and configure it via server.xml and web.xml.
This will prompt you for credentials automatically, everytime you are trying to access your application. You don't have any application-side implementation to do for that.

What I can tell you now is that you already did most of the 'dirty' job integrating Jersey with Spring. I recommend to you to go an Application-based solution, is it does not tie you to a particular container. Spring Security can be intimidating at first, but then when you tame the beast, you see it was actually a friendly puppy.
The fact is that Spring Security is hugely customizable, just by implementing their interfaces. And there is a lot of documentation and support. Plus, you already have a Spring based application.
As all you seek is guidance, I can provide you with some tutorials. You can take advantage from this blog.
http://www.baeldung.com/rest-with-spring-series/
http://www.baeldung.com/2011/10/31/securing-a-restful-web-service-with-spring-security-3-1-part-3/

Related

Implement basic Authentication for rest api using Jersey 2

I have exposed some rest api using Jersey 2(Tomcat server) and successfully implemented Basic authentication(only needed authentication stuff not authorization) using ContainerRequestFilter filter as below
public class AuthFilter implements ContainerRequestFilter{
#Context
HttpServletRequest request;
#Override
public void filter(ContainerRequestContext context) {
............................
//getting username/password authorization header and validating
When I told the same to my Lead, he said don't use filters as every time your rest api is hit, this filter will get invoked.Therefore, implement basic authentication security at container level.I am using Tomcat server.
In web.xml, this is defined
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
Is the above he is referring to?
Can anyone please guide me how to implement the way my lead is saying?
The documentation gives you examples on how to configure this via web.xml. You'll need to configure this using a login-config that belongs to a realm. The web container then takes care of securing resources based on URL patterns.
Note that the data is sent in plain text (in encoded form) via a HTTP header, so you'll need to think of ways to ensure that is not snooped on (like HTTPS).
Whether you check this header on a filter or on the container does not relieve you of the overhead required for making the check (which is probably negligible, but I've never profiled this area of the code to quote numbers).

Spring Access Control

I working on Spring MVC app. The app funcionality is accessible through ReST API which jsp containing ajax logic consume. I am using spring security with defined roles (USER, COMPANY, ADMIN). Methods use requestMapping with responseBody such as:
www.app.com/auth/{userId}/request/{requestId}
It, of course, support GET for obtaining resource and POST for its creating or updating.
The problem is that after succesful login with, for example, userId = 1 I want GET request with requestId = 99. But when I run WebDev client for Chrome, I can also access another resource with easy request in format
www.app.com/auth/5/request/{requestId}
So basically, I can access resources, which I am not allowed to see. I hope you got the idea, where I am heading.
My question is - What is the best approach to secure this?
I was thinking about storing logged user Id (Integer) in session and comparing it everytime request for resource is made, but it seems to me that I am pulling the wrong end of rope :)
Thank you for any advice
You should have a look into the Expression-Based Access Control section of the spring security documentation.
Example copied from the documentation:
#PreAuthorize("#contact.name == authentication.name")
public void doSomething(Contact contact) {
..
}
This would check if name of the contact is equal to the name of the currently logged in user.
Using this this feature you can build much more sophisticated access rules than you could do with simple roles. However, this does not exclude using roles. You can still keep roles for basic security checks.

Spring Security 3.2 Token Authentication

I know this has been asked already, but I am not able to get it to work.
Here is what I would like to get accomplished:
I am using Spring Security 3.2 to secure a REST-like service. No server side sessions.
I am not using basic auth, because that would mean that I need to store the user's password in a cookie on client side. Otherwise the user would need to login with each page refresh/ change. Storing a token is I guess the lesser evil.
A web client (browser, mobile app) calls a REST-like URL to login "/login" with username and password
The server authenticates the user and sends a token back to the client
The client stores the token and adds it to the http request header with each api call
The server checks the validity of the token and sends a response accordingly
I did not even look at the token generation part yet. I know it is backwards, but I wanted to get the token validation part implemented first.
I am trying to get this accomplished by using a custom filer (implementation of AbstractAuthenticationProcessingFilter), however I seem to have the wrong idea about it.
Defining it like this:
public TokenAuthenticationFilter() {
super("/");
}
will only trigger the filter for this exact URL.
I am sticking to some sample implementation, where it calls AbstractAuthenticationProcessingFilter#requiresAuthentication which does not accept wildcards.
I can of course alter that behavior, but this somehow makes me think that I am on the wrong path.
I also started implementing a custom AuthenticationProvider. Maybe that is the right thing?
Can someone give me a push into the right direction?
I think pre-auth filter is a better fit for your scenario.
Override AbstractPreAuthenticatedProcessingFilter's getPrincipal and getCredentials methods.
In case the token is not present in the header, return null from getPrincipal.
Flow:
User logs in for the first time, no header passed, so no
authentication object set in securityContext, normal authentication
process follows i.e. ExceptionTranslation filter redirtects the user
to /login page based on form-logon filter or your custom authenticationEntryPoint
After successful authentication, user requests secured url, pre-auth filter gets token from header authentication object set in
securityContext, if user have access he is allowed to access secured
url

Authentication in RESTful Java web service for mobile clients

I have found numerous academic answers to this question, but I would like one from practitioners in the field.
Background
I would like to create a Java-based RESTful API, using the Grails framework for a variety of mobile clients (iOS and Android) to access protected resources through my service. I require authentication on certain requests, and I already have SSL setup over the wire (so all requests occur over https). My web API will eventually be exposed as a service to other web applications.
Problem
What authentication method do people recommend for a web service that is to be consumed by mobile devices, and eventually other web applications?
These are what I see as my choices. Can you tell me when would be appropriate use cases for each one?
I can do HTTP Basic authentication
I can do HTTP Digest authentication
I can implement OAuth authentication (1.0 or 2.0)?
I can pass the credentials as parameters in my request
I can use an authentication method above, and then pass a delegate/token around for authentication
I can implement my own custom HTTP authentication headers
I can use cookies and pass those to the server on each request
Other...?
Need
If you have one leaning one way or another, I'd like to know why you would choose that method. Better yet, if you're doing this in Grails, I'm very interested.
I already know...
I've already read through the excellent answers here and Richardson and Ruby's book, Restful Web Services.
REST is stateless protocol, thus using "work sessions" - I mean login/work/(auto)logout concept is somewhat questionable. Sending credentials as a parameter with each request seems to be the most often used method due to its simplicity. Just keep in mind that
1) The api url must be SSL only - it makes sense to use a dedicated domain AND ip address, e.g. api.example.com and configure your web server to handle SSL only for this address and domain. Just to avoid accidental disclosure of credentials.
2) Avoid using login/password with the request if possible, use "API key" (a shared secret) instead. You always may use "API key" instead of login/password if authentication is all you need, that is you do not need authorization (all users share the same permissions) and no need for logging (who did what).
3) Rather than sending the API key with each request, it is better to "sign" the request using shared secret and supply the signature. With the key long enough you may use this technique over plain unencrypted http.
=== responding to a comment ===
If you need authorization, just use basic authentication:
HTTPBuilder builder = new HTTPBuilder("https://api.example.com/v1/foo/bar")
builder.auth.basic(login, password)
builder.headers.put('Accept', 'application/json')
def result = builder.request(POST, JSON) { req ->
body = [
....
]
response.'201' = { resp, json ->
....
}
response.success = { resp, json ->
....
}
response.failure = { resp ->
log.error "failure, ${resp.statusLine}"
}
}

Authentication in multiple methods with JAX-RS/Jersey - How to keep it clean?

I'm working on a web service written in Java using JAX-RS/Jersey and Spring.
The WS authenticates a user when he or she logs in and returns an access key which has a limited lifespan. Most of the available methods require a valid "access key + userId" combination.
For all of the available methods I am using #FormParam to retrieve POST parameters, and the response is in JSON. What I am trying to figure out is how to avoid having to type out
#FormParam("userId") final Integer userId,
#FormParam("accessKey") final String accessKey
and manually invoke my authentication method for each of the probably 20 methods I will have that require authentication. This is especially cumbersome because I will then also have to add code to handle e.g. expired access keys.
Is there another way to go about retrieving the two parameters above and performing authentication so I can keep my methods clean?
Since you're using Jersey, you can use servlet-filter-like APIs to DRY up your code. Check out:
Equivalent of Servlet Filter for Jersey / JAX-RS / REST resources?
How does one intercept a request during the Jersey lifecycle?
ContainerRequestFilter

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