Overview

In Cube, authorization (or access control) is based on the security context. The diagram below shows how it works during the request processing in Cube:

Authentication is handled outside of Cube. A typical use case would be:

1. A web server serves an HTML page containing the Cube client, which needs to communicate securely with the Cube API.
2. The web server should generate a JWT with an expiry to achieve this. The server could include the token in the HTML it serves or provide the token to the frontend via an XHR request, which is then stored it in local storage or a cookie.
3. The JavaScript client is initialized using this token, and includes it in calls to the Cube API.
4. The token is received by Cube, and verified using any available JWKS (if configured)
5. Once decoded, the token claims are injected into the security context.

Generating JSON Web Tokens (JWT)

Authentication tokens are generated based on your API secret. Cube CLI generates an API Secret when a project is scaffolded and saves this value in the .env file as CUBEJS_API_SECRET.

You can generate two types of tokens:

• Without security context, which will mean that all users will have the same data access permissions.
• With security context, which will allow you to implement role-based security models where users will have different levels of access to data.

You can find a library to generate JWTs for your programming language here (opens in a new tab).

In Node.js, the following code shows how to generate a token which will expire in 30 days. We recommend using the jsonwebtoken package for this.

const jwt = require("jsonwebtoken");
const CUBE_API_SECRET = "secret";
 
const cubeToken = jwt.sign({}, CUBE_API_SECRET, { expiresIn: "30d" });

Then, in a web server or cloud function, create a route which generates and returns a token. In general, you will want to protect the URL that generates your token using your own user authentication and authorization:

app.use((req, res, next) => {
  if (!req.user) {
    res.redirect("/login");
    return;
  }
  next();
});
 
app.get("/auth/cubejs-token", (req, res) => {
  res.json({
    // Take note: Cube expects the JWT payload to contain an object!
    token: jwt.sign(req.user, process.env.CUBEJS_API_SECRET, {
      expiresIn: "1d",
    }),
  });
});

Then, on the client side, (assuming the user is signed in), fetch a token from the web server:

let apiTokenPromise;
 
const cubeApi = cube(
  () => {
    if (!apiTokenPromise) {
      apiTokenPromise = fetch(`${API_URL}/auth/cubejs-token`)
        .then((res) => res.json())
        .then((r) => r.token);
    }
    return apiTokenPromise;
  },
  {
    apiUrl: `${API_URL}/cubejs-api/v1`,
  }
);

You can optionally store this token in local storage or in a cookie, so that you can then use it to query the Cube API.

Using JSON Web Key Sets (JWKS)

Configuration

As mentioned previously, Cube supports verifying JWTs using industry-standard JWKS. The JWKS can be provided either from a URL, or as a JSON object conforming to JWK specification RFC 7517 Section 4 (opens in a new tab), encoded as a string.

Using a key as a JSON string

Add the following to your cube.js configuration file:

module.exports = {
  jwt: {
    key: "<JWK_AS_STRING>",
  },
};

Or configure the same using environment variables:

CUBEJS_JWT_KEY='<JWK_AS_STRING>'

Using a key from a URL

Add the following to your cube.js configuration file:

module.exports = {
  jwt: {
    jwkUrl: "<URL_TO_JWKS_JSON>",
  },
};

Or configure the same using environment variables:

CUBEJS_JWK_URL='<URL_TO_JWKS_JSON>'

Verifying claims

Cube can also verify the audience, subject and issuer claims in JWTs. Similarly to JWK configuration, these can also be configured in the cube.js configuration file:

module.exports = {
  jwt: {
    audience: "<AUDIENCE_FROM_IDENTITY_PROVIDER>",
    issuer: ["<ISSUER_FROM_IDENTITY_PROVIDER>"],
    subject: "<SUBJECT_FROM_IDENTITY_PROVIDER>",
  },
};

Using environment variables:

CUBEJS_JWT_AUDIENCE='<AUDIENCE_FROM_IDENTITY_PROVIDER>'
CUBEJS_JWT_ISSUER='<ISSUER_FROM_IDENTITY_PROVIDER>'
CUBEJS_JWT_SUBJECT='<SUBJECT_FROM_IDENTITY_PROVIDER>'

Custom claims namespace

Cube can also extract claims defined in custom namespaces. Simply specify the namespace in your cube.js configuration file:

module.exports = {
  jwt: {
    claimsNamespace: "my-custom-namespace",
  },
};

Caching

Cube caches JWKS by default when CUBEJS_JWK_URL or jwt.jwkUrl is specified.

• If the response contains a Cache-Control header, then Cube uses it to determine cache expiry.
• The keys inside the JWKS are checked for expiry values and used for cache expiry.
• If an inbound request supplies a JWT referencing a key not found in the cache, the cache is refreshed.

Custom authentication

Cube also allows you to provide your own JWT verification logic by setting a checkAuth() function in the cube.js configuration file. This function is expected to verify a JWT and assigns its' claims to the security context.

As an example, if you needed to retrieve user information from an LDAP server, you might do the following:

module.exports = {
  checkAuth: async (req, auth) => {
    try {
      const userInfo = await getUserFromLDAP(req.get("X-LDAP-User-ID"));
      req.securityContext = userInfo;
    } catch {
      throw new Error("Could not authenticate user from LDAP");
    }
  },
};