axum/examples/oauth.rs
2021-08-18 00:04:15 +02:00

237 lines
7.5 KiB
Rust

//! Example OAuth (Discord) implementation.
//!
//! Run with
//!
//! ```not_rust
//! CLIENT_ID=123 CLIENT_SECRET=secret cargo run --example oauth --features=headers
//! ```
use async_session::{MemoryStore, Session, SessionStore};
use axum::{
async_trait,
body::{Bytes, Empty},
extract::{Extension, FromRequest, Query, RequestParts, TypedHeader},
handler::get,
response::{IntoResponse, Redirect},
route,
routing::RoutingDsl,
AddExtensionLayer,
};
use http::{header::SET_COOKIE, HeaderMap};
use oauth2::{
basic::BasicClient, reqwest::async_http_client, AuthUrl, AuthorizationCode, ClientId,
ClientSecret, CsrfToken, RedirectUrl, Scope, TokenResponse, TokenUrl,
};
use serde::{Deserialize, Serialize};
use std::{env, net::SocketAddr};
// Quick instructions:
// 1) create a new application at https://discord.com/developers/applications
// 2) visit the OAuth2 tab to get your CLIENT_ID and CLIENT_SECRET
// 3) add a new redirect URI (For this example: http://localhost:3000/auth/authorized)
// 4) AUTH_URL and TOKEN_URL may stay the same for discord.
// More information: https://discord.com/developers/applications/792730475856527411/oauth2
static COOKIE_NAME: &str = "SESSION";
#[tokio::main]
async fn main() {
// Set the RUST_LOG, if it hasn't been explicitly defined
if std::env::var("RUST_LOG").is_err() {
std::env::set_var("RUST_LOG", "hello_world=debug")
}
tracing_subscriber::fmt::init();
// `MemoryStore` just used as an example. Don't use this in production.
let store = MemoryStore::new();
let oauth_client = oauth_client();
let app = route("/", get(index))
.route("/auth/discord", get(discord_auth))
.route("/auth/authorized", get(login_authorized))
.route("/protected", get(protected))
.route("/logout", get(logout))
.layer(AddExtensionLayer::new(store))
.layer(AddExtensionLayer::new(oauth_client));
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
tracing::debug!("listening on {}", addr);
axum::Server::bind(&addr)
.serve(app.into_make_service())
.await
.unwrap();
}
fn oauth_client() -> BasicClient {
// Environment variables (* = required):
// *"CLIENT_ID" "123456789123456789";
// *"CLIENT_SECRET" "rAn60Mch4ra-CTErsSf-r04utHcLienT";
// "REDIRECT_URL" "http://127.0.0.1:3000/auth/authorized";
// "AUTH_URL" "https://discord.com/api/oauth2/authorize?response_type=code";
// "TOKEN_URL" "https://discord.com/api/oauth2/token";
let client_id = env::var("CLIENT_ID").expect("Missing CLIENT_ID!");
let client_secret = env::var("CLIENT_SECRET").expect("Missing CLIENT_SECRET!");
let redirect_url = env::var("REDIRECT_URL")
.unwrap_or_else(|_| "http://127.0.0.1:3000/auth/authorized".to_string());
let auth_url = env::var("AUTH_URL").unwrap_or_else(|_| {
"https://discord.com/api/oauth2/authorize?response_type=code".to_string()
});
let token_url = env::var("TOKEN_URL")
.unwrap_or_else(|_| "https://discord.com/api/oauth2/token".to_string());
BasicClient::new(
ClientId::new(client_id),
Some(ClientSecret::new(client_secret)),
AuthUrl::new(auth_url).unwrap(),
Some(TokenUrl::new(token_url).unwrap()),
)
.set_redirect_uri(RedirectUrl::new(redirect_url).unwrap())
}
// The user data we'll get back from Discord.
// https://discord.com/developers/docs/resources/user#user-object-user-structure
#[derive(Debug, Serialize, Deserialize)]
struct User {
id: String,
avatar: Option<String>,
username: String,
discriminator: String,
}
// Session is optional
async fn index(user: Option<User>) -> impl IntoResponse {
match user {
Some(u) => format!(
"Hey {}! You're logged in!\nYou may now access `/protected`.\nLog out with `/logout`.",
u.username
),
None => "You're not logged in.\nVisit `/auth/discord` to do so.".to_string(),
}
}
async fn discord_auth(Extension(client): Extension<BasicClient>) -> impl IntoResponse {
let (auth_url, _csrf_token) = client
.authorize_url(CsrfToken::new_random)
.add_scope(Scope::new("identify".to_string()))
.url();
// Redirect to Discord's oauth service
Redirect::found(auth_url.to_string().parse().unwrap())
}
// Valid user session required. If there is none, redirect to the auth page
async fn protected(user: User) -> impl IntoResponse {
format!(
"Welcome to the protected area :)\nHere's your info:\n{:?}",
user
)
}
async fn logout(
Extension(store): Extension<MemoryStore>,
TypedHeader(cookies): TypedHeader<headers::Cookie>,
) -> impl IntoResponse {
let cookie = cookies.get(COOKIE_NAME).unwrap();
let session = match store.load_session(cookie.to_string()).await.unwrap() {
Some(s) => s,
// No session active, just redirect
None => return Redirect::found("/".parse().unwrap()),
};
store.destroy_session(session).await.unwrap();
Redirect::found("/".parse().unwrap())
}
#[derive(Debug, Deserialize)]
struct AuthRequest {
code: String,
state: String,
}
async fn login_authorized(
Query(query): Query<AuthRequest>,
Extension(store): Extension<MemoryStore>,
Extension(oauth_client): Extension<BasicClient>,
) -> impl IntoResponse {
// Get an auth token
let token = oauth_client
.exchange_code(AuthorizationCode::new(query.code.clone()))
.request_async(async_http_client)
.await
.unwrap();
// Fetch user data from discord
let client = reqwest::Client::new();
let user_data: User = client
// https://discord.com/developers/docs/resources/user#get-current-user
.get("https://discordapp.com/api/users/@me")
.bearer_auth(token.access_token().secret())
.send()
.await
.unwrap()
.json::<User>()
.await
.unwrap();
// Create a new session filled with user data
let mut session = Session::new();
session.insert("user", &user_data).unwrap();
// Store session and get corresponding cookie
let cookie = store.store_session(session).await.unwrap().unwrap();
// Build the cookie
let cookie = format!("{}={}; SameSite=Lax; Path=/", COOKIE_NAME, cookie);
// Set cookie
let mut headers = HeaderMap::new();
headers.insert(SET_COOKIE, cookie.parse().unwrap());
(headers, Redirect::found("/".parse().unwrap()))
}
struct AuthRedirect;
impl IntoResponse for AuthRedirect {
type Body = Empty<Bytes>;
type BodyError = <Self::Body as axum::body::HttpBody>::Error;
fn into_response(self) -> http::Response<Self::Body> {
Redirect::found("/auth/discord".parse().unwrap()).into_response()
}
}
#[async_trait]
impl<B> FromRequest<B> for User
where
B: Send,
{
// If anything goes wrong or no session is found, redirect to the auth page
type Rejection = AuthRedirect;
async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
let Extension(store) = Extension::<MemoryStore>::from_request(req)
.await
.expect("`MemoryStore` extension is missing");
let cookies = TypedHeader::<headers::Cookie>::from_request(req)
.await
.expect("could not get cookies");
let session_cookie = cookies.get(COOKIE_NAME).ok_or(AuthRedirect)?;
let session = store
.load_session(session_cookie.to_string())
.await
.unwrap()
.ok_or(AuthRedirect)?;
let user = session.get::<User>("user").ok_or(AuthRedirect)?;
Ok(user)
}
}