Atbash Summer release train

Introduction

All the Atbash repositories are still under heavy development, that is why they are released in one go. The last few days, such a release of almost all libraries is performed.

This gives a short overview of what you can find.

Big features

The big feature changes can be found in

  • Atbash JWT support related to cryptographic key support.
  • Atbash Rest client, a Java 7 port of the MicroProfile spec.
  • And Atbash Octopus where KeyCloak and MicroProfile JWT auth spec and interoperability between schemes are central in this release.

Cryptographic key support

Since there are many formats in which keys can be persisted (PEM, Java Key Stores, JWK, etc …), they are all internally stored as an AtbashKey. It contains the Key itself (as Java object), the identification and the type of the key (like RSA, private or public part, etc …)

Creating such keys can be achieved by using the class KeyGenerator, with the method generateKeys(). This class is available as CDI instance or can be instantiated directory in those environments/locations where no CDI is available.

The parameter of the generateKeys() method, defines which key(s) is created. This parameter can be created using a builder pattern.

RSAGenerationParameters generationParameters = new RSAGenerationParameters.RSAGenerationParametersBuilder()
        .withKeyId("the-kid")
        .build();
List<AtbashKey> atbashKeys = generator.generateKeys(generationParameters);

In the above example, multiple keys are generated since RSA is an asymmetric key and thus private and public parts are generated.

Writing of a key can be performed with the KeyWriter class. It has a method, writeKeyResource, which can be used to persist a key into one of the formats. The format is specified as a parameter of type KeyResourceType. This can indicate the required format like PEM, Key store, JWK, etc…

The specific type of PEM (like PKCS1, PKCS8, etc …) is defined by the configuration parameters.

Another parameter defines the password/passphrase for the key (if needed) and one for the file as a whole in the case of the Java KeyStore format for example.

The last functionality around key is then reading of all those keys in the supported format. This functionality is implemented in the KeyReader class. It is again a CDI bean which can be instantiated when no CDI environment is available.

It contains a readKeyResource() method which can read  all the keys in a resource (like PEM file, Java Key Store, JWK, etc …) As a parameter, an instance of KeyResourcePasswordLookup is supplied which retrieves a password in those case where it is needed (to read the file or decrypt the key)

The return of the method is a list because a resource can contain more than one key AtbashKeys.

This Key support is an initial version and will be improved in the further releases of the atbash-jwt-support releases with more features and more supported formats.

Atbash Rest Client

A first release was done mid-June and contained an implementation in Java 7 for Java SE and Java EE which is compatible with the MicroProfile Rest Client specification. (see here) It allows you to ‘inject’ or create (useful in Java SE environments) a system generated Rest client based on the definition of your JAX-RS endpoint defined in an interface class.

In this release, the RestClientBuilderListener from the MP Rest Client spec 1.1 is added and implemented so that we can define some additional providers in a general way. This is important for the Octopus release so that we can add the credentials, stored within the Octopus context, to the JAX-RS call automatically. Without the need to specify the providers manually.

Atbash Octopus

And of course, many new features are added to Octopus. They are migrated from the old Octopus or newly added.

The highlights are:

– Added support for KeyCloak server. JSF applications can use the authentication and authorization from KeyCloak configured realms. Also, the AccessToken from it can be based on in the header of other request and verified by JAX-RS endpoints. The only thing which is needed is the location of the KeyCloak server and the realm config in JSON (which is supplied by KeyCloak)

– The SPI option to pass the expected password for a user can now handle hashed passwords. Both the ‘standard’ algorithms from MessageDigest, like SHA-256 but also the key derivation function PBKDF2 can be defined easily.

– The authorization annotations, like @RequiresPermissions, can be specified on JAX-RS methods without the need to define those resources as CDI or EJB beans.

– Authentication and authorization information can be converted automatically to an MP JWT Auth compliant format and used in calls to JAX-RS endpoints. This makes it possible for example integrate JAX-RS resources protected by KeyCloak and MP JWT seamless.

And too much other features to describe here in detail. The user manual is also started and will be announced soon.

Overview all released frameworks

Utilities : 0.9.2

Set of utilities for Java SE, CDI and plain JSF which are very useful in many projects running in one of these environments.

  • Added utility class for HEX encoding (next to the BASE64 encoding)
  • Added support for byte arrays and encoding (HEX and BASE64) through the ByteSource class.

JSON-smart : 0.9.1

A small library (for Java 7) which can convert JSON to Java instances and vice versa.

  • Added support for @JsonProperty to define the name of JSON property.
  • Contains an SPI so that other naming annotations (like Jackson one) can be used.

Abash-config : 0.9.2

Extension for the MicroProfile Config implementations. Also a Java 7 port of Apache Geronimo Config.

  • Configuration for the base name (with serviceLoader class) is optional.
  • Port of MicroProfile Config 1.3 features to Java 7.

JWT Support : 0.9.0

Convert Java instances to JWT and vice versa and extensive support for Cryptographic keys (reading, writing, creating) supporting multiple types (like RSA, EC, and HMAC keys) and formats (like JWK, JWKSet, PEM, and KeyStore)

  • Support for reading and writing multiple formats (PEM, KeyStore, JWK and JWKSet).
  • Better support for JWT verification with keys using the concepts of KeySelector and KeyManager.

Atbash config server : 0.9.1

Configuration source for MP Config as a server supplying config through JAX-RS endpoints.

  • Added Payara micro as supported server to serve the configuration.

Atbash Rest Client : 0.5.1

Rest client implementation for Java 7.

  • Included RestClientBuilderListener from MP Rest Client 1.1 (to be able to define providers globally)

Octopus : 0.4

  • Integration with Keycloak (Client Credentials for Java SE, AuthorizationCode grant for Web, AccessToken for JAX-RS)
  • Supported for Hashed Passwords (MessageDigest ones and PBKDF2)
  • Support for MP rest Client and Providers available to add tokens for MP JWT Auth and Keycloak.
  • Logout functionality for Web.
  • Authentication events.
  • More features for JAX-RS integration (authorization violations on JAX-RS resource [no need for CDI or EJB], correct 401 return messages, … )
  • Support for default user filter (no need to define user filter before authorizationFilter)

Conclusion

The release contains a lot of goodies related to secure. In the comings months, new features will be added, support for Java 8 and 11 are planned and user manuals and cookbooks will be available to get you started with all those goodies.

The Atbash repositories with some more info and the code of course, can be found at GitHub.

Have fun.

MicroProfile Rest Client for Java SE

Introduction

One of the cool specifications produced by the MicroProfile group is the Rest Client for MicroProfile  available from MP release 1.3.

It builds on top of the Client API of JAX-RS and allows you to use type-safe access to your endpoints without the need to programmatic interact with the Client API.

MicroProfile compliant server implementations need to implement this specification, but nothing says we cannot expand the usage into other environments (with a proper implementation) like use in Java SE (JavaFX seems must useful here) and plain Java EE.

Atbash has created an implementation of the specification so that it can be used in these environments and will use it within Octopus framework to propagate authentication and authorization information automatically in calls to JAX-RS endpoints.

The specification

A few words about the specification itself. JAX-RS 2.x contains a client API which allows you to access any ‘Rest’ endpoint in a uniform way.

Client client = ClientBuilder.newClient();
WebTarget employeeWebTarget = client.target("http://localhost:8080/demo/data").path("employees");
employeeWebTarget.request(MediaType.APPLICATION_JSON).get(new GenericType<List<Employee>>() {
});

This client API is great because we can use it to call any endpoint, not even limited to Java ones. As long as they behave in a standard way.

But things can be improved, by moving away from the programmatic way of performing these calls, into a more declarative way.

If we could define some kind of interface like this

@Path("/employees")
public interface EmployeeService {

@GET
@Produces(MediaType.APPLICATION_JSON)
List<Employee> getAll();
}

And we just could ask an implementation of this interface which performs the required steps of creating the Client, WebTarget and invoke it for us in the background. This would make it much easier for the developer and makes it much more type-safe.

Creating the implementation of that interface is what MicroProfile Rest Client is all about.

The interface defined above can then be injected in any other CDI bean (need to add the @RegisterRestClient on the interface and preferably a CDI scope like @ApplicationScoped) and by calling the method, we actually perform a call to the endpoint and retrieve the result.

@Inject
@RestClient
private EmployeeService employeeService;

public void doSomethingWithEmployees() {
....
... employeeService.getAll();
....
}

Atbash Rest Client

The specification also allows for a programmatic retrieval of the implementation, for those scenarios where no CDI is available.
However, remember that if we are running inside a CDI container, we can always retrieve some CDI bean by using

CDI.current().select();

from within any method.

The programmatic retrieval is thus an ideal candidate to use it in other environments or frameworks like JavaFX (basically every Java SE program), Spring, Kotlin, etc …

The programmatic retrieval starts from the RestClientBuilder with the newBuilder() method.

EmployeeService employeeService = RestClientBuilder.newBuilder()
    .baseUrl(new URL("http://localhost:8080/server/data"))
    .build(EmployeeService.class);

The above retrieves also an implementation for the Employee retrieval endpoint we used earlier on in this text.

For more information about the features like Exception handling, adding custom providers and more, look at the specification document.

The Atbash Rest Client is an implementation in Java 7 which can run on Java SE. It is created mainly for the Octopus Framework to propagate the user authentication (like username) and authorization information (like permissions) to JAX-RS endpoints in a transparent, automatically way.

A ClientRequestFilter is created in Octopus which creates a JWT token (compatible with MicroProfile JWT auth specification) containing username and permissions of the current user and this Filter can then be added as a provider to the MicroProfile Rest Client to have this security information available within the header of the call.

Since the current Octopus version is still based on Java SE 7, no other existing implementation could be used (MicroProfile is Java SE 8 based). The implementation is based on the DeltaSpike Proxy features and uses any Client API compatible implementation which is available at runtime.

Compliant, not certified.

Since all the MicroProfile specifications are Java 8 based, the API is also converted to Java SE 7. Except for a few small incompatibilities, the port is 100% interchangeable.

The most notable difference is creating the builder with the newBuilder() method. In the original specification, this is a static method of an interface which is not allowed in Java 7. For that purpose, an abstract class is created, AbstractRestClientBuilder which contains the method.

Other than that, class and method names should be identical, which makes the switch from Atbash Rest Client to any other implementation using Java 8 very smooth.

The Maven dependency has following coordinates (available on Maven Central):

<dependency>
   <groupId>be.atbash.mp.rest-client</groupId>
   <artifactId>atbash-rest-client-impl</artifactId>
   <version>0.5</version>
</dependency>

If you are running on Java 8, you can use the Apache CXF MicroProfile Rest client

<dependency>
   <groupId>org.apache.cxf</groupId>
   <artifactId>cxf-rt-rs-mp-client</artifactId>
   <version>3.2.4</version>
</dependency>

Which also can be used in a plain Java SE environment. Other implementations like the ones within Liberty and Payara Micro aren’t useable standalone in Java SE.

Remark

This first release of Atbash Rest Client is a pre-release, meaning that not all features of the specification are completely implemented. It is just a bare minimum for the a POC within Octopus.
For example, the handling of exceptions (because the endpoint returned a status in the range 4xx or 5xx) isn’t completely covered yet.

The missing parts will be implemented or improved in a future version.

Conclusion

With the MicroProfile Rest Client specification, it becomes easy to call some JAX-RS endpoints in a type-safe way. By using a declarative method, calling some endpoint becomes as easy as calling any other method within the JVM.

And since micro-services need to be called at some point from non-micro-service code, Java SE executable implementation is very important. It makes it possible to call it from plain Java EE, Java SE, any other framework or a JVM based language.

Have fun.

Atbash repositories overview

Now that I’m working a bit more than 6 months on the Atbash repositories, it is time to give you some overview of them.

For the moment, almost all of them are geared towards Java EE 7 and Java 7.

The idea is to create a MicroProfile compatible experience on Java EE 7. As much as possible of course. Since MicroProfile is based on Java 8, it is not always easy (or possible) to have an identical experience.

But the idea is to give the developers the possibility to have a “smooth” migration from Java EE 7 to MicroProfile by having all or the most important specifications, available on those servers.

Utility repository

Github

This contains some code used in multiple other Atbash repositories. It is not directly related to the goal but can have some usages in any project.

utils-se

– BASE64 encoder and decoder
– Utility class related to searching classes and resources on different class loaders (Current Thread, class loader of utility class or System class loader) and instantiating classes with advanced argument matching.
– Reading library or framework version from manifest file
– Check to see if an application is running within a CDI container
– Utilities related to verification and handling proxies (like determining original class)

– Reflection utilities useable in unit testing (so that we can read and set private properties without the need for setters and getters which would only be needed for testing)

utils-cdi

– Programmatic retrieval of CDI Beans, also for an optional bean (bean defined by Producer method which may or may not be present)
– Retrieval of a bean defined by Producer method involving generic types (issue due to type erasure)

– Fake bean manager useable within unit tests to supply some Mock Cdi bean instances when using programmatic CDI bean retrieval.

utils-jsf

– Creating a method expression based on the expression value
– Retrieving property values from JSF components (taking into account expressions and static values)
– Custom component finding which starts at the parent itself but then extends to the parent until found or view root is reached.

Atbash JSON (Java SE)

GitHub

Alternative JSON-B implementation (not following the specs!) to convert Java instances to JSON and vice versa. The code is adapted from the JSON smart framework (no longer maintained) for the use cases within Atbash (see Atbash JWT support) and extended to have customizations.

JWT Support (Java SE + CDI)

GitHub

The code in this repository is to support JWT (JSON Web Token, signed but also encrypted) as they appear in protocols like OAuth2 and OpenId Connect.

To support this encoding and decoding, there is also a unified handling of cryptographic keys. It is capable of reading them from a PEM file, a Java Keystore, a JWK and a JWKSet. Various encrypted formats for the Private Key are supported.

But the idea goes a bit further than just support OpenId Connect JWTs. Instead of exchanging data as JSON, why not exchange them as JWT. That way, we are not only transferring information but also make some guarantees like sender verification and end to end protection as we can detect changes through the signing.

Atbash Config (Java SE + CDI)

GitHub

The Atbash config is a Java 7 port of the MicroProfile Config specification and the Apache Geronimo implementation.

But there are also some extensions created like
– Support for custom named configuration files.
– Support for Stages so that based on a system property, values can be overridden in environments like Test environment.
– Support for custom formatted date values
– Logging of configuration values at startup of the application.
– Support for YAML format.

There is also a Config provider for testing available where the configuration values are stored in a HashMap.

Atbash Config server (MicroProfile Product)

GitHub

Allows defining the configuration values for MicroProfile application in a central place. These applications can retrieve the values using a JAX-RS endpoint.

There is also a client implementation available which, when added to the application, retrieves the values automatically, based on the configured endpoint of the config server.

Jerry (JSF)

GitHub

Jerry defines a JSF Renderer interceptor which allows you to perform various tasks on any JSF component.

It is the basis for a more advanced validation mechanism for JSF and the declarative security features of Octopus for JSF components.

Valerie (JSF, Bean Validation)

GitHub

Using the interceptor mechanism of Jerry, Valerie places the validation constraints of the Java properties (like not null, length etc) automatically on the JSF components it uses.
This way it allows to have the visual aspects of these constraints on the JSF component HTML representation and JSF validation without the need to put these constraints as JSF attribute values.

Octopus (Java SE, Java FX, CDI, JSF, JAX-RS)

GitHub

Octopus is a large framework consisting of small artifacts that bring you every aspect of authentication and authorization for Java EE and MicroProfile applications.

  • Permission-based framework
  • Secures URL, JSF components, and CDI and EJB method calls
  • Support for Java SE, JavaFX, JAX-RS and JSF
  • Integrates with OAuth2, OpenId Connect, LDAP, database, JWT, KeyCloak, CAS, …
  • Custom OpenId Connect solution within a microservices environment
  • Compatible with (and using) Microprofile (Config, Rest Client, MP-JWT, …), Java EE Security API, …
  • Very flexible, can be easily integrated within your application
  • Tightly integrated with CDI
  • Type-safe definition of permissions
  • Declarative declaration of JSF security (with tags, not using rendered attribute)
  • A custom voter can be created for more complex security requirements

Dependencies overview

The following Neo4J graph gives you an overview of the dependencies between these repositories and the relation with other libraries. Octopus is left out of the image because it would complicate it too much.

Have fun