Authentication and Authorization - REST Security

Overview

This page describes the security layers of the REST web app. There are two security layers:

1. Authentication: 
   1. Client-authentication: The database table OAUTH_CLIENT_DETAILS describes the servers, which are allowed to make calls to the REST web app. (Typically this will be the selfcare web app and, when in development, the Swagger UI)
   2. User/Operator/App-authentication: A username/password based security layer that upon each requests matches a token from the request against an in-memory map from token to logged in users.
      
      
2. Authorization: A fine grained access rights control implemented in all resources that shall have limited access. This layer is customizabile: The customer can register their own rules. The default rules are all based on "ownership": Account-ownership, BillingGroup-ownership and Subscription-ownership.

Authentication

Authentication is triggered by the Authorization layer. If a resource does not require Authorization, then it is considered open for access, unless brand access check is in place. The Authentication protocol used is OAUTH2  and the implementation used is from Spring Framework.

In order to call REST resources that require Authorization, the calling client has to provide an Access Token. Obtaining an Access Token can be done by calling a specific URL. There are three strategies/scenarios to obtain an Access Token.

1. User-authentication  - this corresponds to a Selfcare use-case scenario. The authentication is done by validation username/password in the USERS table. An URL example for this scenario is (note grant_type=password value):
   
   

   Authentication URL

   https://host:port/appcontext/oauth/token?username=#myusername&password=#mypassword&grant_type=password&brand_key=#myBrandKey

   CURL example

   CURL example:  curl -v -X POST -u myclientid:myclientsecret http://host:port/appcontext/oauth/token -H "Accept: application/json" -d "grant_type=password&username=#myusername&password=mypassword&brand_key=#myBrandKey"
   
   where:
   #myusername, #mypassword are taken from Users table
   #myBrandKey is taken from the Brand table
   myclientid, myclientsecret are taken from OAUTH_CLIENT_DETAILS table

   Angular example

   function login(credentials) {
         var data = 'username=' +
           encodeURIComponent(credentials.username) +
           '&password=' +
           encodeURIComponent(credentials.password) +
           '&grant_type=password&scope=read%20write&' +
           'client_id=myclientid&' +
           'brand_key=myBrandKey';
         return $http
           .post('/oauth/token',
               data,
               {
                 headers : {
                   'Content-Type' : 'application/x-www-form-urlencoded',
                   'Accept' : 'application/json',
                   'Authorization' : 'Basic ' +
                     base64Service.encode('myclientid'	+ ':' + 'myclientsecret')
                 }
               }).success(
                 function(response) {
                   //store the access token
                   return response;
                 });
       } 
    
    
   where:
   credentials.username, credentials.password are taken from Users table
   myBrandKey is taken from the Brand table
   myclientid, myclientsecret are taken from OAUTH_CLIENT_DETAILS table

2. Operator-authentication - this correspnds to a Customercare use-case scenario. The authentication is done by validation username/password in the OPERATORS table. An URL example for this scenario is (note grant_type=operator_password value):
   
   

   Authorization URL

   https://host:port/appcontext/oauth/token?username=#myusername&password=#mypassword&grant_type=operator_password&brand_key=#myBrandKey

   CURL example

   CURL example:  curl -v -X POST -u myclientid:myclientsecret http://host:port/appcontext/oauth/token -H "Accept: application/json" -d "grant_type=operator_password&username=#myusername&password=mypassword&brand_key=#myBrandKey"
   
   where:
   #myusername, #mypassword are taken from Operators table
   #myBrandKey is taken from the Brand table
   myclientid, myclientsecret are taken from OAUTH_CLIENT_DETAILS table

Authorization

Authorization is done in two steps:

1. Brand Access
   In order to obtain an access token, the client has to have configured the proper authorization. That is, in the OAUTH_CLIENT_DETAILS table, a client has to have defined proper values in AUTHORITIES column. Those authorities must have the following prefix: ACCESS_BRAND_ .After the prefix there should be the brand_key (uppercase) that the respective client has access to. The brand_key parameter should be sent as QUERY parameter in the request for the token.
   
   Example of registered client:

   CLIENT_ID	RESOURCE_IDS	CLIENT_SECRET	SCOPE	AUTHORIZED_GRANT_TYPES	WEB_SERVRE_REDIRECT_URI	AUTHORITIES	ACCESS_TOKEN_VALIDITY	ADDITIONAL_INFORMATION	AUTOAPROVE
   swagger-ui		swagger-ui-secret	read,write	password,operator_password,client_credentials		ACCESS_BRAND_BRAND_X	600

   
   
   Example: given a brand key with a value of RATOR_X , the authority tag should be ACCESS_BRAND_RATOR_X .
   If a client has access to multiple brands, those should be separated by ,  (e.g ACCESS_BRAND_RATOR_X, ACCESS_BRAND_RATOR_Y)

   CURL example

   CURL example:  curl -v -X POST -u myclientid:myclientsecret http://host:port/appcontext/oauth/token -H "Accept: application/json" -d "grant_type=operator_password&username=#myusername&password=mypassword&brand_key=RATOR_X"
   

2. Fine-grained access control is about limiting the access to specific resources, or even to limit the access to code blocks within a single resource. The current version of the REST app uses our own framework for this. The framework defines two abstract classes, whose implementations stand in a one-to-one relationship with a resource (an @Path annotated method). The two classes reflect the kind of questions/checks needed in the code.

• AccessController: Implementations must implement a single method called assertAccessible(AccessContext), which returns a boolean. This method is called before entering the resource.
• AccessRestrictor:  Implementations must implement a single method called restrict(List<?>). This is called before returning Lists of objects, and provided the customer with an opportunity to filter away restricted resources (such as Subscriptions, for which the caller does not have some sort of ownership over.
• Customizations: both AccessController and AccessRestrictor use the resource path (URL) in order to determine what kind of access control to apply. The mappings are stored in a map structure as in the example below:
  
  

// URL - /accounts/{account-id}/subscriptions
map.put(key(HttpMethod.GET,ResourcePathParent.ACCOUNTS, ResourcePath.ACCOUNTID_SUBSCRIPTIONS),new AccessControllerByOwnership(Ownership.SUB_OR_BG_OR_ACC_OWNER));
 
//URL - /accounts/{account-id}/documents
map.put(key(HttpMethod.POST,ResourcePathParent.ACCOUNTS,ResourcePath.ACCOUNTID_DOCUMENTS),new AccessControllerByOwnership(Ownership.ACC_OWNER));
 
//URL - /accounts/{account-id}/documents
map.put(key(HttpMethod.GET,ResourcePathParent.ACCOUNTS,ResourcePath.ACCOUNTID_DOCUMENTS),new AccessControllerByOwnership(Ownership.ACC_OWNER));
 
//URL - /accounts/{account-id}/billing-groups
map.put(key(HttpMethod.GET, ResourcePathParent.ACCOUNTS,ResourcePath.ACCOUNTID_BILLING_GROUPS),new AccessControllerByOwnership(Ownership.BG_OR_ACC_OWNER));

In a customer project, additional mappings need to be added and this can be achieved by implementing the com.cdrator.selfcare.model.security.ownershipcontrol.AccessByOwnershipConfigurationBuilder (respectively com.cdrator.selfcare.model.security.ownershipcontrol.RestrictForOwnershipConfigurationBuilder) interface(s) and using the ServiceLoader feature to load the implementation(s).

Brand Access Check

In case of a multi branded  environment it is possible to restrict access to the "public" endpoints by enabling the brand access check in the configuration file (Properties.txt). This is done by setting the following parameter:

rest.api.security.public.brand_access_check=true

When the above parameter is in place an access token (Authorization: Bearer access_token) is required to be sent in the request. For public endpoints one can obtain a access token by using the "client_credentials" grant type. 

https://host:port/appcontext/oauth/token?grant_type=client_credentials&brand_key=a_valid_brand_key

CURL example:  curl -v -X POST -u myclientid:myclientsecret http://host:port/appcontext/oauth/token -H "Accept: application/json" -d "grant_type=client_credentials&brand_key=#myBrandKey"

where:
myclientid, myclientsecret are taken from OAUTH_CLIENT_DETAILS table
#myBrandKey is taken from the Brand table

CORS

In order to be able to access both the AUTH app and REST app from Javascript clients, CORS parameters need to be configured. Below there is an example of how that can be done:

rest.auth.cors.allowed-origins=*
rest.auth.cors.allowed-methods=GET, PUT, POST, DELETE, OPTIONS
rest.auth.cors.allowed-headers=*
rest.auth.cors.exposed-headers=
rest.auth.cors.max-age=3600 

rest.api.cors.allowed-origins=*
rest.api.cors.allowed-methods=GET, PUT, POST, DELETE, OPTIONS
rest.api.cors.allowed-headers=Origin, X-Requested-With, Content-Type, Accept, Authorization, X-RATOR-brand-key
rest.api.cors.exposed-headers=
rest.api.cors.max-age=3600