Sample Backend for Java

This repository contains a sample backend code that demonstrates how to generate a Virgil JWT using the Java/Android SDK

Do not use this authentication in production. Requests to a /virgil-jwt endpoint must be allowed for authenticated users. Use your application authorization strategy.

Prerequisites

• Java Development Kit (JDK) 8+

For IntelliJ IDEA Ultimate run:

• IntelliJ IDEA Ultimate 2018.3.3+

If you have Community version of IDEA - go to Building a Jar section.

For building a jar:

• Maven 3+

IntelliJ IDEA Ultimate run

• git clone https://github.com/VirgilSecurity/sample-backend-java
• Open IntelliJ IDEA -> File -> New -> Project from Existing Sources, locate sample-backend-java and click open
• Select Import project from external model -> Maven, go next till Please select project SDK page
• Select in list of available JDKs 1.8.xxx version or greater. If you haven't JDK of 1.8.xxx version install it. Finish setup.
• Fill in your credentials into the sample-backend-java/src/main/resources/application.properties file.
• Run application

If server started successfully you will see in the end of logs:

: Tomcat started on port(s): 3000 (http)
: Started ServerApplication

If you get error Error:java: javacTask: source release 8 requires target release 1.8 go to IntelliJ IDEA -> Preferences -> Build, Execution, Deployment -> Compiler -> Java Compiler and select 8 in Project bytecode version field.

Get Virgil Credentials

If you don't have an account yet, sign up for one using your e-mail.

To generate a JWT the following values are required:

Variable Name	Description
virgil.app.id	ID of your Virgil Application.
virgil.app.private_key	Private key of your APP key that is used to sign the JWTs.
virgil.app.key_id	ID of your APP key. A unique string value that identifies your account in the Virgil Cloud.

Building a Jar

Possibly, you want to build a Jar to deploy it on a remote server (e.g. Now, Heroku).

Clone

Clone the repository from GitHub.

$ git clone https://github.com/VirgilSecurity/sample-backend-java

Build sources

$ mvn clean package -DskipTests

JAR file will be build in target directory.

Add Virgil Credentials to application.properties

• open target directory at the project folder
• create a application.properties file
• fill it with your account credentials (take a look at the application.properties file to find out how to setup your own application.properties file)
• save the application.properties file

Run the Server

$ java -jar server.jar

Now, use your client code to make a request to get a JWT from the sample backend that is working on http://localhost:3000.

You can verify the server with a command:

$ curl -X POST -H "Content-Type: application/json" \
  -d '{"identity":"my_identity"}' \
  http://localhost:3000/authenticate

The response should looks like:

{"authToken":"my_identity-b5ba1680-4d5c-4b2e-9890-a0500d3c9bfe"}

Specification

/authenticate endpoint

This endpoint is an example of users authentication. It takes user identity and responds with unique token.

POST https://localhost:3000/authenticate HTTP/1.1
Content-type: application/json;

{
    "identity": "string"
}

Response:

{
    "authToken": "string"
}

/virgil-jwt endpoint

This endpoint checks whether a user is authorized by an authorization header. It takes user's authToken, finds related user identity and generates a virgilToken (which is JSON Web Token) with this identity in a payload. Use this token to make authorized api calls to Virgil Cloud.

GET https://localhost:3000/virgil-jwt HTTP/1.1
Content-type: application/json;
Authorization: Bearer <authToken>

Response:

{
    "virgilToken": "string"
}

Virgil JWT Generation

To generate JWT, you need to use the JwtGenerator class from the SDK.

public JwtGenerator jwtGenerator() throws CryptoException {
    VirgilCrypto crypto = new VirgilCrypto();
    PrivateKey privateKey = crypto.importPrivateKey(ConvertionUtils.base64ToBytes(this.appKey));
    AccessTokenSigner accessTokenSigner = new VirgilAccessTokenSigner();

    JwtGenerator jwtGenerator = new JwtGenerator(appId, privateKey, appKeyIdentifier,
        TimeSpan.fromTime(1, TimeUnit.HOURS), accessTokenSigner);

    return jwtGenerator;
}

Then you need to provide an HTTP endpoint which will return the JWT with the user's identity as a JSON.

For more details take a look at the AuthenticationService.java file.

License

This library is released under the 3-clause BSD License.

Support

Our developer support team is here to help you. Find out more information on our Help Center.

You can find us on Twitter or send us email support@VirgilSecurity.com.

Also, get extra help from our support team on Slack.