feat(server/webhook): only accept authorised messages

Closes kemitix/git-next#47

src/server/actors/repo/mod.rs

@@ -1,13 +1,14 @@
 mod branch;
 mod config;
 pub mod status;
-mod webhook;
+pub mod webhook;
 
 use actix::prelude::*;
 use kxio::network::Network;
 use tracing::{info, warn};
 
 use crate::server::{
+    actors::repo::webhook::WebhookAuth,
     config::{RepoConfig, RepoDetails, Webhook},
     forge,
     git::Git,
@@ -19,7 +20,7 @@ pub struct RepoActor {
     details: RepoDetails,
     webhook: Webhook,
     webhook_id: Option<WebhookId>, // INFO: if [None] then no webhook is configured
-    webhook_auth: Option<ulid::Ulid>,
+    webhook_auth: Option<WebhookAuth>, // INFO: if [None] then no webhook is configured
     last_main_commit: Option<forge::Commit>,
     last_next_commit: Option<forge::Commit>,
     last_dev_commit: Option<forge::Commit>,
@@ -168,7 +169,7 @@ impl Handler<StartMonitoring> for RepoActor {
 
 #[derive(Message)]
 #[rtype(result = "()")]
-pub struct WebhookRegistered(pub WebhookId, pub ulid::Ulid);
+pub struct WebhookRegistered(pub WebhookId, pub WebhookAuth);
 impl Handler<WebhookRegistered> for RepoActor {
     type Result = ();
     fn handle(&mut self, msg: WebhookRegistered, _ctx: &mut Self::Context) -> Self::Result {

src/server/actors/repo/webhook.rs

@@ -1,8 +1,9 @@
 use actix::prelude::*;
 use kxio::network::{self, json};
 use tracing::{debug, info, warn};
+use ulid::DecodeError;
 
-use std::{fmt::Display, ops::Deref};
+use std::{fmt::Display, ops::Deref, str::FromStr};
 
 use crate::server::{
     actors::{
@@ -33,6 +34,29 @@ impl Display for WebhookId {
     }
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct WebhookAuth(ulid::Ulid);
+impl WebhookAuth {
+    pub fn from_str(authorisation: &str) -> Result<Self, DecodeError> {
+        let id = ulid::Ulid::from_str(authorisation);
+        Ok(Self(id?))
+    }
+
+    fn generate() -> Self {
+        Self(ulid::Ulid::new())
+    }
+
+    fn header_value(&self) -> String {
+        format!("Basic {}", self.0.to_string())
+    }
+}
+impl Deref for WebhookAuth {
+    type Target = ulid::Ulid;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 pub async fn unregister(
     webhook_id: WebhookId,
     repo_details: crate::server::config::RepoDetails,
@@ -82,10 +106,10 @@ pub async fn register(
     let webhook_url = webhook.url();
     let repo_alias = repo_details.name;
     let headers = network::NetRequestHeaders::new().with("Content-Type", "application/json");
-    let authorisation = ulid::Ulid::new();
+    let authorisation = WebhookAuth::generate();
     let body = json!({
       "active": true,
-      "authorization_header": format!("Basic {}", authorisation),
+      "authorization_header": authorisation.header_value(),
       "branch_filter": format!("{{{},{},{}}}", repo_config.branches().main(), repo_config.branches().next(), repo_config.branches().dev()),
       "config": {
         "content_type": "json",
@@ -130,6 +154,9 @@ impl Handler<WebhookMessage> for RepoActor {
 
     #[allow(clippy::cognitive_complexity)] // TODO: (#49) reduce complexity
     fn handle(&mut self, msg: WebhookMessage, ctx: &mut Self::Context) -> Self::Result {
+        if msg.authorisation() != self.webhook_auth {
+            return; // invalid auth
+        }
         let id = msg.id();
         let body = msg.body();
         debug!(?id, "RepoActor received message");

src/server/actors/webhook/message.rs

@@ -1,11 +1,14 @@
 //
 use actix::prelude::*;
 
+use crate::server::actors::repo::webhook::WebhookAuth;
+
 #[derive(Message, Debug, Clone)]
 #[rtype(result = "()")]
 pub struct WebhookMessage {
     id: String,
     path: String,
+    authorisation: String,
     // query: String,
     // headers: warp::http::HeaderMap,
     body: String,
@@ -17,6 +20,7 @@ impl WebhookMessage {
         // query: String,
         // headers: warp::http::HeaderMap,
         body: String,
+        authorisation: String,
     ) -> Self {
         Self {
             id,
@@ -24,6 +28,7 @@ impl WebhookMessage {
             // query,
             // headers,
             body,
+            authorisation,
         }
     }
     pub const fn id(&self) -> &String {
@@ -41,4 +46,7 @@ impl WebhookMessage {
     pub const fn body(&self) -> &String {
         &self.body
     }
+    pub fn authorisation(&self) -> Option<WebhookAuth> {
+        WebhookAuth::from_str(&self.authorisation).ok()
+    }
 }

src/server/actors/webhook/server.rs

@@ -12,24 +12,39 @@ pub async fn start(address: actix::prelude::Recipient<super::message::WebhookMes
         .map(move || address.clone())
         .and(warp::path::param())
         // .and(warp::query::raw())
-        // .and(warp::header::headers_cloned())
+        .and(warp::header::headers_cloned())
         .and(warp::body::bytes())
         .and_then(
             |recipient: Recipient<WebhookMessage>,
              path,
              // query: String,
-             // headers: warp::http::HeaderMap,
+             headers: warp::http::HeaderMap,
              body: bytes::Bytes| async move {
                 let bytes = body.to_vec();
                 let request_data = String::from_utf8_lossy(&bytes).to_string();
                 let id = ulid::Ulid::new().to_string();
-                debug!(id, path, "Received webhook");
-                let message =
-                    WebhookMessage::new(id, path, /* query, headers, */ request_data);
-                recipient
-                    .try_send(message)
-                    .map(|_| warp::reply::with_status("OK", warp::http::StatusCode::OK))
-                    .map_err(|_| warp::reject::reject())
+                match headers.get("Authorization") {
+                    Some(auhorisation) => {
+                        debug!(id, path, "Received webhook");
+                        let authorisation = auhorisation
+                            .to_str()
+                            .map_err(|_| warp::reject())? // valid characters
+                            .strip_prefix("Basic ")
+                            .ok_or_else(warp::reject)? // must start with "Basic "
+                            .to_string();
+                        let message = WebhookMessage::new(
+                            id,
+                            path,
+                            /* query, headers, */ request_data,
+                            authorisation,
+                        );
+                        recipient
+                            .try_send(message)
+                            .map(|_| warp::reply::with_status("OK", warp::http::StatusCode::OK))
+                            .map_err(|_| warp::reject())
+                    }
+                    _ => Err(warp::reject()),
+                }
             },
         );