From 5eabc89280d22c50d0df0d3dee5f676bf77190da Mon Sep 17 00:00:00 2001
From: Jacob Lifshay <programmerjake@gmail.com>
Date: Mon, 8 Apr 2024 03:00:24 -0700
Subject: [PATCH] auth works, getting email not yet

---
 Cargo.lock         |  1 +
 Cargo.toml         |  1 +
 config.toml.sample |  2 ++
 src/app.rs         | 74 +++++++++++++++++++++++++++++++++++++++++++---
 src/config.rs      |  4 ++-
 5 files changed, 77 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 09d7ba4..b03dd48 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2287,6 +2287,7 @@ dependencies = [
  "futures",
  "indexmap 2.2.6",
  "listenfd",
+ "log",
  "openidconnect",
  "serde",
  "serde_json",
diff --git a/Cargo.toml b/Cargo.toml
index 132b3e3..7dfd291 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ eyre = "0.6.12"
 futures = "0.3.30"
 indexmap = { version = "2.2.6", features = ["serde"] }
 listenfd = "1.0.1"
+log = "0.4.21"
 openidconnect = "3.5.0"
 serde = { version = "1.0.197", features = ["derive"] }
 serde_json = "1.0.115"
diff --git a/config.toml.sample b/config.toml.sample
index 9713ecb..da14b88 100644
--- a/config.toml.sample
+++ b/config.toml.sample
@@ -3,6 +3,7 @@ pretty_name = "Google"
 issuer_url = "https://accounts.google.com"
 client_id = "<TODO>"
 secret = "<TODO>"
+redirect_url = "https://my-site/subscription/callback/google"
 scopes = ["email"]
 
 [oidc.debian-salsa]
@@ -10,4 +11,5 @@ pretty_name = "Debian Salsa"
 issuer_url = "https://salsa.debian.org"
 client_id = "<TODO>"
 secret = "<TODO>"
+redirect_url = "https://my-site/subscription/callback/debian-salsa"
 scopes = ["email"]
diff --git a/src/app.rs b/src/app.rs
index 7ff156a..edac951 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -5,16 +5,18 @@ use actix_web::{
     get,
     http::{
         header::{ContentType, LOCATION},
+        uri::PathAndQuery,
         StatusCode, Uri,
     },
     web::{self, ServiceConfig},
     HttpResponse, HttpResponseBuilder, Responder,
 };
 use openidconnect::{
-    core::CoreAuthenticationFlow, http::HeaderValue, CsrfToken, EndUserEmail, Nonce,
+    core::CoreAuthenticationFlow, http::HeaderValue, reqwest::async_http_client, url::Url,
+    AuthorizationCode, CsrfToken, EndUserEmail, Nonce, RedirectUrl, TokenResponse,
 };
 use serde::{Deserialize, Serialize};
-use std::{fmt::Write, marker::PhantomData};
+use std::{borrow::Cow, fmt::Write, marker::PhantomData};
 use tinytemplate::TinyTemplate;
 
 pub trait DynTemplate {
@@ -125,12 +127,76 @@ impl OIDCProvider {}
 const NONCE: &'static str = "nonce";
 const CSRF_TOKEN: &'static str = "csrf_token";
 
+#[derive(Deserialize)]
+struct AuthQuery {
+    code: AuthorizationCode,
+    state: CsrfToken,
+}
+
+#[get("/subscription/callback/{provider}")]
+pub async fn callback(
+    config: web::Data<Config>,
+    session: Session,
+    path: web::Path<(String,)>,
+    query: web::Query<AuthQuery>,
+) -> impl Responder {
+    let mut resp = HttpResponse::SeeOther().body("");
+    resp.headers_mut()
+        .insert(LOCATION, "/subscription".parse().unwrap());
+    if SessionState::get(&session).is_some() {
+        return resp;
+    }
+    let Ok(Some(csrf_token)) = session.get::<CsrfToken>(CSRF_TOKEN) else {
+        return resp;
+    };
+    let Ok(Some(nonce)) = session.get::<Nonce>(NONCE) else {
+        return resp;
+    };
+    session.remove(CSRF_TOKEN);
+    session.remove(NONCE);
+    if csrf_token.secret() != query.state.secret() {
+        return resp;
+    }
+    let Some(provider) = config.oidc.get(&path.0) else {
+        return resp;
+    };
+    let token = match provider
+        .state()
+        .client
+        .exchange_code(query.into_inner().code)
+        .request_async(async_http_client)
+        .await
+    {
+        Ok(token) => token,
+        Err(e) => {
+            log::warn!("Error getting token: {e}");
+            return resp;
+        }
+    };
+    dbg!(&token);
+    let claims = match token
+        .id_token()
+        .unwrap()
+        .claims(&provider.state().client.id_token_verifier(), &nonce)
+    {
+        Ok(claims) => claims,
+        Err(e) => {
+            log::warn!("Error verifying token: {e}");
+            return resp;
+        }
+    };
+    let Some(email) = claims.email().cloned() else {
+        return resp;
+    };
+    SessionState { email }.set(&session);
+    resp
+}
+
 #[get("/subscription/login/{provider}")]
 pub async fn login(
     config: web::Data<Config>,
     session: Session,
     path: web::Path<(String,)>,
-    uri: Uri,
 ) -> impl Responder {
     let mut resp = HttpResponse::SeeOther().body("");
     resp.headers_mut()
@@ -179,7 +245,7 @@ pub async fn subscription(config: web::Data<Config>, session: Session) -> impl R
 }
 
 pub fn all_services(cfg: &mut ServiceConfig) {
-    cfg.service(subscription).service(login);
+    cfg.service(subscription).service(login).service(callback);
 }
 
 #[cfg(test)]
diff --git a/src/config.rs b/src/config.rs
index 331374b..f45ee18 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -5,7 +5,7 @@ use futures::future::try_join_all;
 use indexmap::IndexMap;
 use openidconnect::{
     core::{CoreClient, CoreProviderMetadata},
-    ClientId, ClientSecret, IssuerUrl, Scope,
+    ClientId, ClientSecret, IssuerUrl, RedirectUrl, Scope,
 };
 use serde::{Deserialize, Serialize};
 
@@ -55,6 +55,7 @@ pub struct OIDCProvider {
     pub issuer_url: IssuerUrl,
     pub client_id: ClientId,
     pub secret: ClientSecret,
+    pub redirect_url: RedirectUrl,
     pub scopes: Vec<Scope>,
     #[serde(skip)]
     state: Option<OIDCProviderState>,
@@ -76,6 +77,7 @@ impl OIDCProvider {
             Some(self.secret.clone()),
         );
         let client = client.disable_openid_scope();
+        let client = client.set_redirect_uri(self.redirect_url.clone());
         self.state = Some(OIDCProviderState {
             client,
             provider_metadata,