From 00742c14a95b774bcba033db89c986c53ea6c4b5 Mon Sep 17 00:00:00 2001
From: projectmoon <projectmoon@agnos.is>
Date: Thu, 10 Jun 2021 15:25:44 +0000
Subject: [PATCH] Add authentication checking to api

---
 Cargo.lock        |  2 ++
 api/Cargo.toml    |  2 ++
 api/src/api.rs    |  3 +++
 api/src/auth.rs   | 49 +++++++++++++++++++++++++++++++++++++++++++++--
 api/src/errors.rs | 16 ++++++++++++++++
 api/src/lib.rs    |  1 +
 6 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 api/src/errors.rs

diff --git a/Cargo.lock b/Cargo.lock
index 8609474..1646bf0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3518,7 +3518,9 @@ dependencies = [
  "rocket",
  "rocket_cors",
  "serde",
+ "substring",
  "tenebrous-rpc",
+ "thiserror",
  "tonic",
  "tracing-subscriber",
 ]
diff --git a/api/Cargo.toml b/api/Cargo.toml
index fbfc0ea..1672bf4 100644
--- a/api/Cargo.toml
+++ b/api/Cargo.toml
@@ -9,6 +9,8 @@ log = "0.4"
 tracing-subscriber = "0.2"
 tonic = { version = "0.4" }
 prost = "0.7"
+thiserror = "1.0"
+substring = "1.4"
 jsonwebtoken = "7.2"
 chrono = "0.4"
 serde = {version = "1.0", features = ["derive"] }
diff --git a/api/src/api.rs b/api/src/api.rs
index 7c18342..d91d99a 100644
--- a/api/src/api.rs
+++ b/api/src/api.rs
@@ -1,3 +1,4 @@
+use crate::auth::User;
 use crate::config::create_config;
 use crate::schema::{self, Context, Schema};
 use log::info;
@@ -26,7 +27,9 @@ async fn post_graphql_handler(
     context: &State<Context>,
     request: juniper_rocket_async::GraphQLRequest,
     schema: &State<Schema>,
+    user: User,
 ) -> juniper_rocket_async::GraphQLResponse {
+    println!("User is {:?}", user);
     request.execute(&*schema, &*context).await
 }
 
diff --git a/api/src/auth.rs b/api/src/auth.rs
index f24b0d0..c29c0d1 100644
--- a/api/src/auth.rs
+++ b/api/src/auth.rs
@@ -1,14 +1,59 @@
 use crate::config::Config;
+use crate::errors::ApiError;
 use chrono::{Duration, Utc};
 use jsonwebtoken::{decode, encode, Algorithm, DecodingKey, EncodingKey, Header, Validation};
-use rocket::http::{Cookie, CookieJar};
+use rocket::request::{self, FromRequest, Request};
 use rocket::response::status::Custom;
 use rocket::{
     http::Status,
     serde::{json::Json, Deserialize, Serialize},
 };
+use rocket::{
+    http::{Cookie, CookieJar},
+    outcome::Outcome,
+};
 use rocket::{routes, Route, State};
-use std::error::Error;
+use substring::Substring;
+
+#[derive(Clone, Debug)]
+pub(crate) struct User {
+    username: String, //TODO more state and such here.
+}
+
+fn decode_token(token: &str, config: &Config) -> Result<Claims, ApiError> {
+    let token_data = decode::<Claims>(
+        token,
+        &DecodingKey::from_secret(config.jwt_secret.as_bytes()),
+        &Validation::default(),
+    )?;
+
+    Ok(token_data.claims)
+}
+
+#[rocket::async_trait]
+impl<'r> FromRequest<'r> for User {
+    type Error = ApiError;
+
+    async fn from_request(req: &'r Request<'_>) -> request::Outcome<Self, Self::Error> {
+        let config: Option<&Config> = req.rocket().state();
+        let auth_header = req
+            .headers()
+            .get_one("Authorization")
+            .map(|auth| auth.substring("Bearer ".len(), auth.len()));
+
+        let token = auth_header
+            .zip(config)
+            .map(|(encoded_token, app_cfg)| decode_token(encoded_token, app_cfg))
+            .unwrap_or(Err(ApiError::AuthenticationDenied("username".to_string())));
+
+        match token {
+            Err(e) => Outcome::Failure((Status::Forbidden, e)),
+            Ok(token) => Outcome::Success(User {
+                username: token.sub,
+            }),
+        }
+    }
+}
 
 pub(crate) fn routes() -> Vec<Route> {
     routes![login]
diff --git a/api/src/errors.rs b/api/src/errors.rs
new file mode 100644
index 0000000..9ae854b
--- /dev/null
+++ b/api/src/errors.rs
@@ -0,0 +1,16 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum ApiError {
+    #[error("user account does not exist: {0}")]
+    UserDoesNotExist(String),
+
+    #[error("invalid password for user account: {0}")]
+    AuthenticationDenied(String),
+
+    #[error("authentication token missing from request")]
+    AuthenticationRequired,
+
+    #[error("error decoding token: {0}")]
+    TokenDecodingError(#[from] jsonwebtoken::errors::Error),
+}
diff --git a/api/src/lib.rs b/api/src/lib.rs
index d2dd013..0de1d7d 100644
--- a/api/src/lib.rs
+++ b/api/src/lib.rs
@@ -1,4 +1,5 @@
 pub mod api;
 pub mod auth;
 pub mod config;
+pub mod errors;
 pub mod schema;