I want to create a service that returns a list of online users. The user logs on using JWT tokens -- but I am unsure how to get online users -- or/and return a list of users but indicate if they are online or not.
Would I have to stash session tokens/emails that have logged on/logged off in the mongodb - and what if they don't log out?
My current code looks like this
#CrossOrigin
#GetMapping("/api/getActiveUsers")
public ResponseEntity<Object> activeUser(HttpServletRequest request) {
TokenManagement user = new TokenManagement();
try {
// return the user authenticate
HttpSession session = request.getSession(true);
List<Object> userListHttp = (List<Object>) Arrays.asList(session.getAttribute("user"));
// alternative way for get user logged
List<String> userList = getUsersFromSessionRegistry();
return ResponseEntity.ok().body(userListHttp);
} catch (Exception e) {
e.printStackTrace();
throw e;
}
}
public List<String> getUsersFromSessionRegistry() {
return sessionRegistry.getAllPrincipals()
.stream()
.filter((u) -> !sessionRegistry.getAllSessions(u, false)
.isEmpty())
.map(o -> {
if (o instanceof Person) {
return ((Person) o).getEmail();
} else {
return o.toString();
}
}).collect(Collectors.toList());
}
You can extract the user from the JWT with its expiring.
Then you can use a cache (consider Redis for example) storing the user on a record that automatically expires when the JWT expires.
If a user explicitly logout simply remove that user from the cache.
So to count the users, you need only to count items in the cache.
This will not grant you that if a client has an error and disconnects without an explicit logout you will have an error on the logged user number, but it is mitigated by the expiring of the cache
I suggest to use a Redis instead of a local cache because it will works also if you are in a microservice environment with multiple instances of your micro service, because the logged users are stored in an external cache common to all microservices instances
You can use a Filter to intercept all the HTTP incoming requests:
A filter is an object that performs filtering tasks on either the request to a resource (a servlet or static content), or on the response from a resource, or both.
public class SessionFilter implements Filter {
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {
HttpServletRequest req = (HttpServletRequest) request;
String bearer = req.getHeader("authorization");
String jwt = bearer.substring(7); // Remove Beared at the beginning
String username = extractUsername(jwt);
Date expiringDate = extractExpiring(jwt);
insertInCache(username, expiringDate);
chain.doFilter(request, response);
}
...
private String extractUsername(String jwt) {
// Use libraries to extract the username from the jwt
}
private Date extractExpiring(String jwt) {
// Use libraries to extract the expiring from the jwt
}
private void insertInCache(String username, Date expiringDate) {
// Insert username in the cache with automatic expiring
}
}
This code will intercept all incoming requests, extract the token, parse it and insert the user in the cache. Consider using any java library to extract the informations from the JWT to create the methods extractUsername and extractExpiring.
This code is just a base code to program. You need to complete it with:
manage not authenticated requests
manage explicit logout (in the controller)
add a method to count users inquiring cache (in the controller)
Related
So, I am working on creating a simple chat app. I'm not using spring security.
So, in front end, the user enters their name which is handled by this controller.
#PostMapping("/addUser")
public User addUser(#RequestBody String name, HttpServletRequest request) {
String session = (String) request.getSession().getAttribute("sessionId");
System.out.println("Session id is " + session);
User newUser = new User(name, session);
userService.addUser(newUser);
System.out.println(newUser);
return newUser;
}
I'm using pre handler method handler interceptor to generate session id for the user. Below is the code:
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("Its working");
// TODO Auto-generated method stub
if(request instanceof HttpServletRequest) {
HttpServletRequest servletRequest = (HttpServletRequest) request;
HttpSession session = servletRequest.getSession();
session.setAttribute("sessionId", session.getId());
System.out.println("Connected with session id : " + session.getAttribute("sessionId"));
}
return true;
}
So, I want to make sure that whenever users are inactive for cetain time, I want to end the session for that user and also remove that user from the arraylist of user where I have kept all the users who register by entering their name (in the front end).
Is it possible to achieve without sprin security or do I have to learn spring security to implement it.
I did try using task scheduler but then I found out in some article that its impossible to call HttpSession there.
You can set the session life (time it can be inactive before being killed) with server.servlet.session.timeout=30m
You can take the user out of your list by implementing a HttpSessionListener.sessionDestroyed - spring-boot-session-listener
if you use WebSocket, You can use heartbeat for your session, on the other hand, if you use rest then you should keep the session in memory(redis, hazelcast, or in-memory (singleton object) like map<key, session>,
(keep in mind, the client should send a disconnect request or you should control it in the backend)
I'm looking for a way to enable token-based authentication in Jersey. I am trying not to use any particular framework. Is that possible?
My plan is: A user signs up for my web service, my web service generates a token, sends it to the client, and the client will retain it. Then the client, for each request, will send the token instead of username and password.
I was thinking of using a custom filter for each request and #PreAuthorize("hasRole('ROLE')"), but I just thought that this causes a lot of requests to the database to check if the token is valid.
Or not create filter and in each request put a param token? So that each API first checks the token and after executes something to retrieve resource.
How token-based authentication works
In token-based authentication, the client exchanges hard credentials (such as username and password) for a piece of data called token. For each request, instead of sending the hard credentials, the client will send the token to the server to perform authentication and then authorization.
In a few words, an authentication scheme based on tokens follow these steps:
The client sends their credentials (username and password) to the server.
The server authenticates the credentials and, if they are valid, generate a token for the user.
The server stores the previously generated token in some storage along with the user identifier and an expiration date.
The server sends the generated token to the client.
The client sends the token to the server in each request.
The server, in each request, extracts the token from the incoming request. With the token, the server looks up the user details to perform authentication.
If the token is valid, the server accepts the request.
If the token is invalid, the server refuses the request.
Once the authentication has been performed, the server performs authorization.
The server can provide an endpoint to refresh tokens.
What you can do with JAX-RS 2.0 (Jersey, RESTEasy and Apache CXF)
This solution uses only the JAX-RS 2.0 API, avoiding any vendor specific solution. So, it should work with JAX-RS 2.0 implementations, such as Jersey, RESTEasy and Apache CXF.
It is worthwhile to mention that if you are using token-based authentication, you are not relying on the standard Java EE web application security mechanisms offered by the servlet container and configurable via application's web.xml descriptor. It's a custom authentication.
Authenticating a user with their username and password and issuing a token
Create a JAX-RS resource method which receives and validates the credentials (username and password) and issue a token for the user:
#Path("/authentication")
public class AuthenticationEndpoint {
#POST
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public Response authenticateUser(#FormParam("username") String username,
#FormParam("password") String password) {
try {
// Authenticate the user using the credentials provided
authenticate(username, password);
// Issue a token for the user
String token = issueToken(username);
// Return the token on the response
return Response.ok(token).build();
} catch (Exception e) {
return Response.status(Response.Status.FORBIDDEN).build();
}
}
private void authenticate(String username, String password) throws Exception {
// Authenticate against a database, LDAP, file or whatever
// Throw an Exception if the credentials are invalid
}
private String issueToken(String username) {
// Issue a token (can be a random String persisted to a database or a JWT token)
// The issued token must be associated to a user
// Return the issued token
}
}
If any exceptions are thrown when validating the credentials, a response with the status 403 (Forbidden) will be returned.
If the credentials are successfully validated, a response with the status 200 (OK) will be returned and the issued token will be sent to the client in the response payload. The client must send the token to the server in every request.
When consuming application/x-www-form-urlencoded, the client must send the credentials in the following format in the request payload:
username=admin&password=123456
Instead of form params, it's possible to wrap the username and the password into a class:
public class Credentials implements Serializable {
private String username;
private String password;
// Getters and setters omitted
}
And then consume it as JSON:
#POST
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public Response authenticateUser(Credentials credentials) {
String username = credentials.getUsername();
String password = credentials.getPassword();
// Authenticate the user, issue a token and return a response
}
Using this approach, the client must to send the credentials in the following format in the payload of the request:
{
"username": "admin",
"password": "123456"
}
Extracting the token from the request and validating it
The client should send the token in the standard HTTP Authorization header of the request. For example:
Authorization: Bearer <token-goes-here>
The name of the standard HTTP header is unfortunate because it carries authentication information, not authorization. However, it's the standard HTTP header for sending credentials to the server.
JAX-RS provides #NameBinding, a meta-annotation used to create other annotations to bind filters and interceptors to resource classes and methods. Define a #Secured annotation as following:
#NameBinding
#Retention(RUNTIME)
#Target({TYPE, METHOD})
public #interface Secured { }
The above defined name-binding annotation will be used to decorate a filter class, which implements ContainerRequestFilter, allowing you to intercept the request before it be handled by a resource method. The ContainerRequestContext can be used to access the HTTP request headers and then extract the token:
#Secured
#Provider
#Priority(Priorities.AUTHENTICATION)
public class AuthenticationFilter implements ContainerRequestFilter {
private static final String REALM = "example";
private static final String AUTHENTICATION_SCHEME = "Bearer";
#Override
public void filter(ContainerRequestContext requestContext) throws IOException {
// Get the Authorization header from the request
String authorizationHeader =
requestContext.getHeaderString(HttpHeaders.AUTHORIZATION);
// Validate the Authorization header
if (!isTokenBasedAuthentication(authorizationHeader)) {
abortWithUnauthorized(requestContext);
return;
}
// Extract the token from the Authorization header
String token = authorizationHeader
.substring(AUTHENTICATION_SCHEME.length()).trim();
try {
// Validate the token
validateToken(token);
} catch (Exception e) {
abortWithUnauthorized(requestContext);
}
}
private boolean isTokenBasedAuthentication(String authorizationHeader) {
// Check if the Authorization header is valid
// It must not be null and must be prefixed with "Bearer" plus a whitespace
// The authentication scheme comparison must be case-insensitive
return authorizationHeader != null && authorizationHeader.toLowerCase()
.startsWith(AUTHENTICATION_SCHEME.toLowerCase() + " ");
}
private void abortWithUnauthorized(ContainerRequestContext requestContext) {
// Abort the filter chain with a 401 status code response
// The WWW-Authenticate header is sent along with the response
requestContext.abortWith(
Response.status(Response.Status.UNAUTHORIZED)
.header(HttpHeaders.WWW_AUTHENTICATE,
AUTHENTICATION_SCHEME + " realm=\"" + REALM + "\"")
.build());
}
private void validateToken(String token) throws Exception {
// Check if the token was issued by the server and if it's not expired
// Throw an Exception if the token is invalid
}
}
If any problems happen during the token validation, a response with the status 401 (Unauthorized) will be returned. Otherwise the request will proceed to a resource method.
Securing your REST endpoints
To bind the authentication filter to resource methods or resource classes, annotate them with the #Secured annotation created above. For the methods and/or classes that are annotated, the filter will be executed. It means that such endpoints will only be reached if the request is performed with a valid token.
If some methods or classes do not need authentication, simply do not annotate them:
#Path("/example")
public class ExampleResource {
#GET
#Path("{id}")
#Produces(MediaType.APPLICATION_JSON)
public Response myUnsecuredMethod(#PathParam("id") Long id) {
// This method is not annotated with #Secured
// The authentication filter won't be executed before invoking this method
...
}
#DELETE
#Secured
#Path("{id}")
#Produces(MediaType.APPLICATION_JSON)
public Response mySecuredMethod(#PathParam("id") Long id) {
// This method is annotated with #Secured
// The authentication filter will be executed before invoking this method
// The HTTP request must be performed with a valid token
...
}
}
In the example shown above, the filter will be executed only for the mySecuredMethod(Long) method because it's annotated with #Secured.
Identifying the current user
It's very likely that you will need to know the user who is performing the request agains your REST API. The following approaches can be used to achieve it:
Overriding the security context of the current request
Within your ContainerRequestFilter.filter(ContainerRequestContext) method, a new SecurityContext instance can be set for the current request. Then override the SecurityContext.getUserPrincipal(), returning a Principal instance:
final SecurityContext currentSecurityContext = requestContext.getSecurityContext();
requestContext.setSecurityContext(new SecurityContext() {
#Override
public Principal getUserPrincipal() {
return () -> username;
}
#Override
public boolean isUserInRole(String role) {
return true;
}
#Override
public boolean isSecure() {
return currentSecurityContext.isSecure();
}
#Override
public String getAuthenticationScheme() {
return AUTHENTICATION_SCHEME;
}
});
Use the token to look up the user identifier (username), which will be the Principal's name.
Inject the SecurityContext in any JAX-RS resource class:
#Context
SecurityContext securityContext;
The same can be done in a JAX-RS resource method:
#GET
#Secured
#Path("{id}")
#Produces(MediaType.APPLICATION_JSON)
public Response myMethod(#PathParam("id") Long id,
#Context SecurityContext securityContext) {
...
}
And then get the Principal:
Principal principal = securityContext.getUserPrincipal();
String username = principal.getName();
Using CDI (Context and Dependency Injection)
If, for some reason, you don't want to override the SecurityContext, you can use CDI (Context and Dependency Injection), which provides useful features such as events and producers.
Create a CDI qualifier:
#Qualifier
#Retention(RUNTIME)
#Target({ METHOD, FIELD, PARAMETER })
public #interface AuthenticatedUser { }
In your AuthenticationFilter created above, inject an Event annotated with #AuthenticatedUser:
#Inject
#AuthenticatedUser
Event<String> userAuthenticatedEvent;
If the authentication succeeds, fire the event passing the username as parameter (remember, the token is issued for a user and the token will be used to look up the user identifier):
userAuthenticatedEvent.fire(username);
It's very likely that there's a class that represents a user in your application. Let's call this class User.
Create a CDI bean to handle the authentication event, find a User instance with the correspondent username and assign it to the authenticatedUser producer field:
#RequestScoped
public class AuthenticatedUserProducer {
#Produces
#RequestScoped
#AuthenticatedUser
private User authenticatedUser;
public void handleAuthenticationEvent(#Observes #AuthenticatedUser String username) {
this.authenticatedUser = findUser(username);
}
private User findUser(String username) {
// Hit the the database or a service to find a user by its username and return it
// Return the User instance
}
}
The authenticatedUser field produces a User instance that can be injected into container managed beans, such as JAX-RS services, CDI beans, servlets and EJBs. Use the following piece of code to inject a User instance (in fact, it's a CDI proxy):
#Inject
#AuthenticatedUser
User authenticatedUser;
Note that the CDI #Produces annotation is different from the JAX-RS #Produces annotation:
CDI: javax.enterprise.inject.Produces
JAX-RS: javax.ws.rs.Produces
Be sure you use the CDI #Produces annotation in your AuthenticatedUserProducer bean.
The key here is the bean annotated with #RequestScoped, allowing you to share data between filters and your beans. If you don't wan't to use events, you can modify the filter to store the authenticated user in a request scoped bean and then read it from your JAX-RS resource classes.
Compared to the approach that overrides the SecurityContext, the CDI approach allows you to get the authenticated user from beans other than JAX-RS resources and providers.
Supporting role-based authorization
Please refer to my other answer for details on how to support role-based authorization.
Issuing tokens
A token can be:
Opaque: Reveals no details other than the value itself (like a random string)
Self-contained: Contains details about the token itself (like JWT).
See details below:
Random string as token
A token can be issued by generating a random string and persisting it to a database along with the user identifier and an expiration date. A good example of how to generate a random string in Java can be seen here. You also could use:
Random random = new SecureRandom();
String token = new BigInteger(130, random).toString(32);
JWT (JSON Web Token)
JWT (JSON Web Token) is a standard method for representing claims securely between two parties and is defined by the RFC 7519.
It's a self-contained token and it enables you to store details in claims. These claims are stored in the token payload which is a JSON encoded as Base64. Here are some claims registered in the RFC 7519 and what they mean (read the full RFC for further details):
iss: Principal that issued the token.
sub: Principal that is the subject of the JWT.
exp: Expiration date for the token.
nbf: Time on which the token will start to be accepted for processing.
iat: Time on which the token was issued.
jti: Unique identifier for the token.
Be aware that you must not store sensitive data, such as passwords, in the token.
The payload can be read by the client and the integrity of the token can be easily checked by verifying its signature on the server. The signature is what prevents the token from being tampered with.
You won't need to persist JWT tokens if you don't need to track them. Althought, by persisting the tokens, you will have the possibility of invalidating and revoking the access of them. To keep the track of JWT tokens, instead of persisting the whole token on the server, you could persist the token identifier (jti claim) along with some other details such as the user you issued the token for, the expiration date, etc.
When persisting tokens, always consider removing the old ones in order to prevent your database from growing indefinitely.
Using JWT
There are a few Java libraries to issue and validate JWT tokens such as:
jjwt
java-jwt
jose4j
To find some other great resources to work with JWT, have a look at http://jwt.io.
Handling token revocation with JWT
If you want to revoke tokens, you must keep the track of them. You don't need to store the whole token on server side, store only the token identifier (that must be unique) and some metadata if you need. For the token identifier you could use UUID.
The jti claim should be used to store the token identifier on the token. When validating the token, ensure that it has not been revoked by checking the value of the jti claim against the token identifiers you have on server side.
For security purposes, revoke all the tokens for a user when they change their password.
Additional information
It doesn't matter which type of authentication you decide to use. Always do it on the top of a HTTPS connection to prevent the man-in-the-middle attack.
Take a look at this question from Information Security for more information about tokens.
In this article you will find some useful information about token-based authentication.
This answer is all about authorization and it is a complement of my previous answer about authentication
Why another answer? I attempted to expand my previous answer by adding details on how to support JSR-250 annotations. However the original answer became the way too long and exceeded the maximum length of 30,000 characters. So I moved the whole authorization details to this answer, keeping the other answer focused on performing authentication and issuing tokens.
Supporting role-based authorization with the #Secured annotation
Besides authentication flow shown in the other answer, role-based authorization can be supported in the REST endpoints.
Create an enumeration and define the roles according to your needs:
public enum Role {
ROLE_1,
ROLE_2,
ROLE_3
}
Change the #Secured name binding annotation created before to support roles:
#NameBinding
#Retention(RUNTIME)
#Target({TYPE, METHOD})
public #interface Secured {
Role[] value() default {};
}
And then annotate the resource classes and methods with #Secured to perform the authorization. The method annotations will override the class annotations:
#Path("/example")
#Secured({Role.ROLE_1})
public class ExampleResource {
#GET
#Path("{id}")
#Produces(MediaType.APPLICATION_JSON)
public Response myMethod(#PathParam("id") Long id) {
// This method is not annotated with #Secured
// But it's declared within a class annotated with #Secured({Role.ROLE_1})
// So it only can be executed by the users who have the ROLE_1 role
...
}
#DELETE
#Path("{id}")
#Produces(MediaType.APPLICATION_JSON)
#Secured({Role.ROLE_1, Role.ROLE_2})
public Response myOtherMethod(#PathParam("id") Long id) {
// This method is annotated with #Secured({Role.ROLE_1, Role.ROLE_2})
// The method annotation overrides the class annotation
// So it only can be executed by the users who have the ROLE_1 or ROLE_2 roles
...
}
}
Create a filter with the AUTHORIZATION priority, which is executed after the AUTHENTICATION priority filter defined previously.
The ResourceInfo can be used to get the resource Method and resource Class that will handle the request and then extract the #Secured annotations from them:
#Secured
#Provider
#Priority(Priorities.AUTHORIZATION)
public class AuthorizationFilter implements ContainerRequestFilter {
#Context
private ResourceInfo resourceInfo;
#Override
public void filter(ContainerRequestContext requestContext) throws IOException {
// Get the resource class which matches with the requested URL
// Extract the roles declared by it
Class<?> resourceClass = resourceInfo.getResourceClass();
List<Role> classRoles = extractRoles(resourceClass);
// Get the resource method which matches with the requested URL
// Extract the roles declared by it
Method resourceMethod = resourceInfo.getResourceMethod();
List<Role> methodRoles = extractRoles(resourceMethod);
try {
// Check if the user is allowed to execute the method
// The method annotations override the class annotations
if (methodRoles.isEmpty()) {
checkPermissions(classRoles);
} else {
checkPermissions(methodRoles);
}
} catch (Exception e) {
requestContext.abortWith(
Response.status(Response.Status.FORBIDDEN).build());
}
}
// Extract the roles from the annotated element
private List<Role> extractRoles(AnnotatedElement annotatedElement) {
if (annotatedElement == null) {
return new ArrayList<Role>();
} else {
Secured secured = annotatedElement.getAnnotation(Secured.class);
if (secured == null) {
return new ArrayList<Role>();
} else {
Role[] allowedRoles = secured.value();
return Arrays.asList(allowedRoles);
}
}
}
private void checkPermissions(List<Role> allowedRoles) throws Exception {
// Check if the user contains one of the allowed roles
// Throw an Exception if the user has not permission to execute the method
}
}
If the user has no permission to execute the operation, the request is aborted with a 403 (Forbidden).
To know the user who is performing the request, see my previous answer. You can get it from the SecurityContext (which should be already set in the ContainerRequestContext) or inject it using CDI, depending on the approach you go for.
If a #Secured annotation has no roles declared, you can assume all authenticated users can access that endpoint, disregarding the roles the users have.
Supporting role-based authorization with JSR-250 annotations
Alternatively to defining the roles in the #Secured annotation as shown above, you could consider JSR-250 annotations such as #RolesAllowed, #PermitAll and #DenyAll.
JAX-RS doesn't support such annotations out-of-the-box, but it could be achieved with a filter. Here are a few considerations to keep in mind if you want to support all of them:
#DenyAll on the method takes precedence over #RolesAllowed and #PermitAll on the class.
#RolesAllowed on the method takes precedence over #PermitAll on the class.
#PermitAll on the method takes precedence over #RolesAllowed on the class.
#DenyAll can't be attached to classes.
#RolesAllowed on the class takes precedence over #PermitAll on the class.
So an authorization filter that checks JSR-250 annotations could be like:
#Provider
#Priority(Priorities.AUTHORIZATION)
public class AuthorizationFilter implements ContainerRequestFilter {
#Context
private ResourceInfo resourceInfo;
#Override
public void filter(ContainerRequestContext requestContext) throws IOException {
Method method = resourceInfo.getResourceMethod();
// #DenyAll on the method takes precedence over #RolesAllowed and #PermitAll
if (method.isAnnotationPresent(DenyAll.class)) {
refuseRequest();
}
// #RolesAllowed on the method takes precedence over #PermitAll
RolesAllowed rolesAllowed = method.getAnnotation(RolesAllowed.class);
if (rolesAllowed != null) {
performAuthorization(rolesAllowed.value(), requestContext);
return;
}
// #PermitAll on the method takes precedence over #RolesAllowed on the class
if (method.isAnnotationPresent(PermitAll.class)) {
// Do nothing
return;
}
// #DenyAll can't be attached to classes
// #RolesAllowed on the class takes precedence over #PermitAll on the class
rolesAllowed =
resourceInfo.getResourceClass().getAnnotation(RolesAllowed.class);
if (rolesAllowed != null) {
performAuthorization(rolesAllowed.value(), requestContext);
}
// #PermitAll on the class
if (resourceInfo.getResourceClass().isAnnotationPresent(PermitAll.class)) {
// Do nothing
return;
}
// Authentication is required for non-annotated methods
if (!isAuthenticated(requestContext)) {
refuseRequest();
}
}
/**
* Perform authorization based on roles.
*
* #param rolesAllowed
* #param requestContext
*/
private void performAuthorization(String[] rolesAllowed,
ContainerRequestContext requestContext) {
if (rolesAllowed.length > 0 && !isAuthenticated(requestContext)) {
refuseRequest();
}
for (final String role : rolesAllowed) {
if (requestContext.getSecurityContext().isUserInRole(role)) {
return;
}
}
refuseRequest();
}
/**
* Check if the user is authenticated.
*
* #param requestContext
* #return
*/
private boolean isAuthenticated(final ContainerRequestContext requestContext) {
// Return true if the user is authenticated or false otherwise
// An implementation could be like:
// return requestContext.getSecurityContext().getUserPrincipal() != null;
}
/**
* Refuse the request.
*/
private void refuseRequest() {
throw new AccessDeniedException(
"You don't have permissions to perform this action.");
}
}
Note: The above implementation is based on the Jersey RolesAllowedDynamicFeature. If you use Jersey, you don't need to write your own filter, just use the existing implementation.
I've been using Google OAuth to let users authorize access to the Calendar Service for my Web Application. After a successful 3-legged auth flow, I was storing all user's credentials in a common file on the app Server. The next time the app needs to use the service, it will check if the credentials exist, and if yes, it will assume they are valid
code works like that
#Override
public void _authorize(String userId) throws IOException {
// Check if user has already authorised the service.
Credential credents = flow.loadCredential(userId);
// Checking if the given user is not authorized
if (credents == null) {
//Create credentials now. user will be redirected to authorise
try {
//Creating a LocalServer Receiver
// Getting the redirect URI
// Creating a new authorization URL
// Setting the redirect URI
// Building the authorization URL
// Receiving authorization code
// Exchanging it for an access token
// Storing the credentials for later access
credents = flow.createAndStoreCredential(response, id);
} finally {
// Releasing resources
}
} else {
// Assume the credentials are valid. so there's nothing left to do here, let's get that client
//Update: Nooooooot! the user might have revoked the authorization, so credents != null BUT they are invalid
//TODO: handle an Exception here, and manage the revoked credentials
}
// Setting up the calendar service client
client = new com.google.api.services.calendar.Calendar.Builder(httpTransport, jsonFactory, credents).setApplicationName(APPLICATION_NAME)
.build();
}
This works fine, as long as the user never changes his mind. But if the user decides to manually revoke the authorization using the Google Account security options, the com.google.api.services.calendar.Calendar retrieval will Fail.
My question is :
Is there a way to check if the credentials are still valid, before trying to use them ?
Else, I can only guess that the failure to get the client object, is the only way to have my portal realize that the credentials are no more valid ?
What should I do about the invalid/revoked credentials ? should I just call flow.createAndStoreCredential and they are going to be overwritten? Or do I have to delete the old ones first ? (how ?)
You can use the refreshToken() method for this. See example:
// Fetch credential using the GoogleAuthorizationCodeFlow
GoogleAuthorizationCodeFlow authorizationCodeFlow;
Credential credential = authorizationCodeFlow.loadCredential(userId);
if (credential != null) {
try {
// refresh the credential to see if the refresh token is still valid
credential.refreshToken();
System.out.println("Refreshed: expires in: " + credential.getExpiresInSeconds());
} catch (TokenResponseException e) {
// process exception here.
// This will catch the Exception.
// This Exception contains the HTTP status and reason etc.
// In case of a revoke, this will throw something like a 401 - "invalid_grant"
return;
}
} else {
// No credential yet known.
// Flow for creating a new credential here
}
EDIT
If you indeed have an invalid refresh token and you want to renew it, then you need to repeat the steps that you did in the first place to get the credentials. So:
genererate a new authorization URL
redirect the user to it
user accepts the consent screen
catch the authorization code from the redirect back to your app
request a new token from Google using the authorization code
create and store a new Credential using the response from Google
No need to delete the old credential. But if you want to explicitly do so, it is possible.
Something like:
// This userId is obviously the same as you used to create the credential
String userId = "john.doe";
authorizationCodeFlow.getDataStore().delete(userId);
You can use the endpoint https://www.googleapis.com/oauth2/v1/tokeninfo to determine if an OAuth2 token is still valid. More information is available in the OAuth2 guide.
Answer to the first question:
When using the Service object for retrieving calendar items from Google Calendar, the token are automatically verified. When they are invalid, they will be refreshed automatically, and stored in the datastore you provided to the flow.
this can also be done manually. A token is valid for 3600 seconds (one hour). When retrieving a token you get this value with the timestamp when it was issued. You could manually determine if a token is valid. If it is not valid call the following async method.
await credents.RefreshtokenAsync(CancellationToken.None);
This function gets you fresh tokens, and stores them in the datastore you provided.
You could check token with tokeninfo and if token is not valid:
- remove credential from datastore
- invoke new auth
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
{
UserService userService = UserServiceFactory.getUserService();
if (userService.isUserLoggedIn()) {
User user = userService.getCurrentUser();
log.info(String.format("LoggedUser: %s %s", user.getEmail(), user.getUserId()));
Credential credential = this.getCredential();
Tokeninfo tokenInfo = OAuth2Utils.getTokenInfo(credential, null);
if (tokenInfo != null)
log.info(String.format("Token expires in: %d", tokenInfo.getExpiresIn()));
else {
OAuth2Utils.deleteCredential(user.getUserId());
response.sendRedirect(request.getRequestURI()); // recall this servlet to require new user authorization
return;
}
}
public static Tokeninfo getTokenInfo(Credential credential, String accessToken) {
Oauth2 service = new Oauth2.Builder(new NetHttpTransport(), Constant.JSON_FACTORY, credential).setApplicationName(Constant.APP_NAME).build();
Tokeninfo tokenInfo = null;
try {
tokenInfo = service.tokeninfo().setAccessToken( accessToken == null ? credential.getAccessToken() : accessToken ).execute();
} catch (IOException e) {
log.warning("An error occurred: " + e);
}
return tokenInfo;
}
I believe I have basic authentication working but I'm not sure how to protect resources so that they can only be accessed when the user is signed in.
public class SimpleAuthenticator implements Authenticator<BasicCredentials, User> {
UserDAO userDao;
public SimpleAuthenticator(UserDAO userDao) {this.userDao = userDao;}
#Override
public Optional<User> authenticate(BasicCredentials credentials) throws AuthenticationException
{
User user = this.userDao.getUserByName(credentials.getUsername());
if (user!=null &&
user.getName().equalsIgnoreCase(credentials.getUsername()) &&
BCrypt.checkpw(credentials.getPassword(), user.getPwhash())) {
return Optional.of(new User(credentials.getUsername()));
}
return Optional.absent();
}
}
My Signin resource is like this:
#Path("/myapp")
#Produces(MediaType.APPLICATION_JSON)
public class UserResource {
#GET
#Path("/signin")
public User signin(#Auth User user) {
return user;
}
}
And I sign the user with:
~/java/myservice $ curl -u "someuser" http://localhost:8080/myapp/signin
Enter host password for user 'someuser':
{"name":"someuser"}
Question
Let's say the user signs in from a browser or native mobile app front end using the /myapp/signin endpoint. How then can I protect another endpoint, say, /myapp/{username}/getstuff which requires a user to be signedin
#GET
#Path("/myapp/{username}/getstuff")
public Stuff getStuff(#PathParam("username") String username) {
//some logic here
return new Stuff();
}
There are 2 things when you are trying to implement REST. One is Authentication (which seems that you have got it working) and other is Authorization (which is what I believe your question is).
The way I have handled it in dropwizard before is, with every user signin, you return some kind of access_token (this proves they authenticated) back to the client which has to be returned by them in EVERY successive call they make as a part of some header (normally this is done through "Authorization" header). On the server side, you will have to save/map this access_token to THAT user before returning it back to the client and when all the successive calls are made with that access_token, you look up the user mapped with that access_token and determine if that user is authorized to access that resource or not. Now an example:
1) User signs in with /myapp/signin
2) You authenticate the user and send back an access_token as a response while saving the same on your side, such as, access_token --> userIdABCD
3) The client comes back to /myapp/{username}/getstuff. If the client does not provided the "Authorization" header with the access_token you gave them, you should return 401 Unauthorized code right away.
4) If the client does provide the access_token, you can look up the user based on that access_token you saved in step # 2 and check if that userId has access to that resource of not. If it does not, return 401 unauthorized code, and if it does have access, return the actual data back.
Now coming ot the "Authorization" header part. You could get access to "Authoroziation" header in all of your calls using the "#Context HttpServletRequest hsr" parameter but does it make sense to add that parameter in each call? No it doesn't. This is where the Security Filters help in dropwizard. Here's an example to how to add security filter.
public class SecurityFilter extends OncePerRequestFilter{
#Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException{
String accessToken = request.getHeader("Authorization");
// Do stuff here based on the access token (check for user's authorization to the resource ...
}
Now, which resource does this security filter really protects? For that you will need to add this filter to the specific resources you want to protect which can be done as follows:
environment.addFilter(SecurityFilter, "/myapp/*");
Remember on thing here that both your urls /myapp/signin and /myapp/{username}/getstuff, both will go through this security filter, BUT, /myapp/signin will NOT have an access_token, obviously because you haven't given any to the client yet. That wil have to be taken care of in the filter itself such as:
String url = request.getRequestURL().toString();
if(url.endsWith("signin"))
{
// Don't look for authorization header, and let the filter pass without any checks
}
else
{
// DO YOUR NORMAL AUTHORIZATION RELATED STUFF HERE
}
The url that you are protecting will depend on the how your urls are structured and what you want to protect. The better urls you design, the easier it will be to write security filters for their protection With the addition of this security filter the flow will be like this:
1) User goes to /myapp/signin. The call will go through the filter and because of that "if" statement, it will continue to your ACTUAL resource of /myapp/signin and you will assign an access_token based on successful authentication
2) User makes a call to /myapp/{username}/mystuff with the access_token. This call will go through the same security filter and will go through the "else" statement where you actually do your authorization. If the authorization goes through, the call will continue to you actual resource handler, and if not authorized, 401 should be returned.
public class SecurityFilter extends OncePerRequestFilter
{
#Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException
{
String url = request.getRequestURL().toString();
String accessToken = request.getHeader("Authorization");
try
{
if (accessToken == null || accessToken.isEmpty())
{
throw new Exception(Status.UNAUTHORIZED.getStatusCode(), "Provided access token is either null or empty or does not have permissions to access this resource." + accessToken);
}
if (url.endsWith("/signin"))
{
//Don't Do anything
filterChain.doFilter(request, response);
}
else
{
//AUTHORIZE the access_token here. If authorization goes through, continue as normal, OR throw a 401 unaurhtorized exception
filterChain.doFilter(request, response);
}
}
catch (Exception ex)
{
response.setStatus(401);
response.setCharacterEncoding("UTF-8");
response.setContentType(MediaType.APPLICATION_JSON);
response.getWriter().print("Unauthorized");
}
}
}
I hope this helps! Took me about 2 days to figure this out myself!
Sorry for being a simple user . I believe you can protect the resource by using a #Auth User user
public Service1Bean Service1Method1(
#Auth User user,
#QueryParam("name") com.google.common.base.Optional<String> name) {
I'm using this ContainerRequestFilter to check HTTP Basic credentials.
private class Filter implements ResourceFilter, ContainerRequestFilter {
#Override
public ContainerRequest filter(ContainerRequest request) {
String auth = request.getHeaderValue("Authorization");
if (auth == null || !auth.startsWith("Basic ")) {
throw new NotAuthorizedException("FAILED\n");
}
auth = Base64.base64Decode(auth.substring("Basic ".length()));
String[] vals = auth.split(":");
String username = vals[0];
String password = vals[1];
boolean validUser = database.Users.validate(username, password);
if (!validUser) {
throw new NotAuthorizedException("FAILED\n");
}
return request;
}
...
}
So by the time I get to this point, I've authenticated the user. Now how I can get the username?
#GET
#Path("some_kind_of_report_or_something")
#Produces(MediaType.TEXT_PLAIN)
public String fetchAReportOrSomething() {
// At this point, I know that the user has provided good credentials,
// now I need get the user's username as a String
String username = ???;
}
I suppose I could use HttpContext.getRequest() and do the same thing as in the AuthFilter (I'd move that username/password extraction logic to its own method). In the filter, can I somehow store the extracted username somewhere in the request object so it gets passed on to this handler?
(By the way, is there a better way to extract the username and password than what I've done in the filter? If so, let me know in a comment.)
This blog entry should enlighten you:
http://plaincode.blogspot.pt/2011/07/openid-authentication-example-in-jersey.html
Take a look how it's done in a working application: www.s3auth.com. The source code is available at github. As you can see on the site, facebook and google authentication mechanisms are used. The application is using JAX-RS/Jersey.