authentication.rs

use actix_web::{
    dev::{forward_ready, Service, ServiceRequest, ServiceResponse, Transform},
    Error,
};
use futures::prelude::future::LocalBoxFuture;
use std::future::{ready, Ready};

pub struct AuthData;

impl<S, B> Transform<S, ServiceRequest> for AuthData
where
    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
    S::Future: 'static,
    B: 'static,
{
    type Response = ServiceResponse<B>;
    type Error = Error;
    type InitError = ();
    type Transform = AuthenticatedMiddleware<S>;
    type Future = Ready<Result<Self::Transform, Self::InitError>>;

    fn new_transform(&self, service: S) -> Self::Future {
        ready(Ok(AuthenticatedMiddleware { service }))
    }
}

pub struct AuthenticatedMiddleware<S> {
    service: S,
}

#[derive(serde::Deserialize)]
struct Credentials {
    id: String,
    password: String,
}

async fn auth(req: &mut ServiceRequest) -> Result<(), Box<dyn actix_web::ResponseError>> {
    let cookie = req.cookie("auth");
    match cookie {
        Some(cookie) => Ok(()),
        None => match req.extract::<actix_web::web::Form<Credentials>>().await {
            Ok(credentials) => Ok(()),
            Err(_) => Err(Box::new(actix_web::ResponseError::status_code(
                actix_web::http::StatusCode::UNAUTHORIZED,
            ))),
        },
    }
}

impl<S, B> Service<ServiceRequest> for AuthenticatedMiddleware<S>
where
    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
    S::Future: 'static,
    B: 'static,
{
    type Response = ServiceResponse<actix_web::body::EitherBody<B>>;
    type Error = Error;
    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;

    forward_ready!(service);

    fn call(&self, req: ServiceRequest) -> Self::Future {
        Box::pin(async move {
            let credentials = req.extract::<actix_web::web::Form<Credentials>>().await;
            let authenticated = auth(&mut req).await;

            if let Err(msg) = authenticated {
                return Ok(req.error_response(Error::from(msg)).map_into_right_body());
            }

            self.service
                .call(req)
                .await
                .map(|res| res.map_into_left_body())
        })
    }
}