Biscuit actix middleware

This middleware allows service-wide extraction and parsing of biscuit tokens.

Authorization itself still need to be handled from within endpoint handlers.

The middleware expects a base64-encoded token through the bearer token HTTP authorization scheme (an Authorization: Bearer <token> HTTP header). This token is deserialized and its cryptographic signatures verified with the provided public key.

• Requests without a bearer token are rejected with a HTTP 401 Unauthorized error;
• Requests with tokens that fail parsing or cryptographic verification are rejected with a HTTP 403 Forbidden error.

Token extraction logic and error handling are configurable (see Configuration example).

Working example

Here is a web server exposing GET /hello, only to tokens containing the role("admin") fact. The public key used for verifying tokens is provided through the BISCUIT_PUBLIC_KEY environment variable.

A complete, runnable example can be found in examples/readme.rs, and can be run with BISCUIT_PUBLIC_KEY=<public key> cargo run --example readme.

Optionally, you can enable tracing by running BISCUIT_PUBLIC_KEY=<public key> cargo run --example readme --features tracing to observe middleware traces as logs in the console.

use actix_web::{get, web, App, HttpResponse, HttpServer};
use biscuit_actix_middleware::BiscuitMiddleware;
use biscuit_auth::{macros::*, Biscuit, PublicKey};

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let public_key = PublicKey::from_bytes_hex(
        &std::env::var("BISCUIT_PUBLIC_KEY")
            .expect("Missing BISCUIT_PUBLIC_KEY environment variable"),
    )
    .expect("Couldn't parse public key");

    HttpServer::new(move || {
        App::new()
            .wrap(BiscuitMiddleware::new(public_key))
            .service(hello)
    })
    .bind(("127.0.0.1", 8080))?
    .run()
    .await
}

#[get("/hello")]
async fn hello(biscuit: web::ReqData<Biscuit>) -> HttpResponse {
    let mut authorizer = authorizer!(
        r#"
      allow if role("admin");
    "#
    );

    authorizer.add_token(&biscuit).unwrap();
    if authorizer.authorize().is_err() {
        return HttpResponse::Forbidden().finish();
    }

    HttpResponse::Ok().body("Hello admin!")
}