change: Remove the nonce cache limit

Don't pass the nonce cache limit everywhere, we allocate the hashmap capacity
with it, so we can use the hashmap capacity directly.

Also refactor the `NonceCache` type, make it better without extension trait.

Suggested-by: Amjad Alsharafi <me@amjad.alsharafi.dev>
Reviewed-by: Amjad Alsharafi <me@amjad.alsharafi.dev>
Signed-off-by: Awiteb <a@4rs.nl>

crates/oxidetalis/src/extensions.rs

@@ -24,9 +24,8 @@ use sea_orm::DatabaseConnection;
 use uuid::Uuid;
 
 use crate::{
-    routes::DEPOT_NONCE_CACHE_SIZE,
+    nonce::NonceCache,
     websocket::{OnlineUsers, ServerEvent, SocketUserData},
-    NonceCache,
 };
 
 /// Extension trait for the Depot.
@@ -37,15 +36,6 @@ pub trait DepotExt {
     fn config(&self) -> &Config;
     /// Retutns the nonce cache
     fn nonce_cache(&self) -> Arc<NonceCache>;
-    /// Returns the size of the nonce cache
-    fn nonce_cache_size(&self) -> &usize;
-}
-
-/// Extension trait for the nonce cache.
-pub trait NonceCacheExt {
-    /// Add a nonce to the cache, returns `true` if the nonce is added, `false`
-    /// if the nonce is already exist in the cache.
-    fn add_nonce(&self, nonce: &[u8; 16], limit: &usize) -> bool;
 }
 
 /// Extension trait for online websocket users
@@ -82,38 +72,6 @@ impl DepotExt for Depot {
                 .expect("Nonce cache not found"),
         )
     }
-
-    fn nonce_cache_size(&self) -> &usize {
-        let s: &Arc<usize> = self
-            .get(DEPOT_NONCE_CACHE_SIZE)
-            .expect("Nonce cache size not found");
-        s.as_ref()
-    }
-}
-
-impl NonceCacheExt for &NonceCache {
-    fn add_nonce(&self, nonce: &[u8; 16], limit: &usize) -> bool {
-        let mut cache = self.lock().expect("Nonce cache lock poisoned, aborting...");
-        let now = Utc::now().timestamp();
-        cache.retain(|_, time| (now - *time) < 30);
-
-        if &cache.len() >= limit {
-            log::warn!("Nonce cache limit reached, clearing 10% of the cache");
-            let num_to_remove = limit / 10;
-            let keys: Vec<[u8; 16]> = cache.keys().copied().collect();
-            for key in keys.iter().take(num_to_remove) {
-                cache.remove(key);
-            }
-        }
-
-        // We can use insert directly, but it's will update the value if the key is
-        // already exist so we need to check if the key is already exist or not
-        if cache.contains_key(nonce) {
-            return false;
-        }
-        cache.insert(*nonce, now);
-        true
-    }
 }
 
 impl OnlineUsersExt for OnlineUsers {

crates/oxidetalis/src/main.rs

@@ -17,7 +17,7 @@
 #![doc = include_str!("../../../README.md")]
 #![warn(missing_docs, unsafe_code)]
 
-use std::{collections::HashMap, process::ExitCode, sync::Mutex};
+use std::process::ExitCode;
 
 use oxidetalis_config::{CliArgs, Parser};
 use oxidetalis_migrations::MigratorTrait;
@@ -27,14 +27,12 @@ mod database;
 mod errors;
 mod extensions;
 mod middlewares;
+mod nonce;
 mod routes;
 mod schemas;
 mod utils;
 mod websocket;
 
-/// Nonce cache type, used to store nonces for a certain amount of time
-pub type NonceCache = Mutex<HashMap<[u8; 16], i64>>;
-
 async fn try_main() -> errors::Result<()> {
     pretty_env_logger::init_timed();
 
@@ -50,6 +48,7 @@ async fn try_main() -> errors::Result<()> {
     let local_addr = format!("{}:{}", config.server.host, config.server.port);
     let acceptor = TcpListener::new(&local_addr).bind().await;
     log::info!("Server listening on http://{local_addr}");
+    log::info!("Chat websocket on ws://{local_addr}/ws/chat");
     if config.openapi.enable {
         log::info!(
             "The openapi schema is available at http://{local_addr}{}",

crates/oxidetalis/src/middlewares/signature.rs

@@ -70,7 +70,7 @@ pub async fn signature_check(
         }
     };
 
-    if !utils::is_valid_nonce(&signature, &depot.nonce_cache(), depot.nonce_cache_size())
+    if !utils::is_valid_nonce(&signature, &depot.nonce_cache()).await
         || !utils::is_valid_signature(
             &sender_public_key,
             &depot.config().server.private_key,

crates/oxidetalis/src/nonce.rs

@@ -0,0 +1,73 @@
+// OxideTalis Messaging Protocol homeserver implementation
+// Copyright (C) 2024 OxideTalis Developers <otmp@4rs.nl>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://gnu.org/licenses/agpl-3.0>.
+
+//! Nonce cache implementation
+
+use std::{collections::HashMap, mem};
+
+use chrono::Utc;
+use oxidetalis_core::types::Size;
+use tokio::sync::Mutex as TokioMutex;
+
+/// Size of each entry in the nonce cache
+pub(crate) const NONCE_ENTRY_SIZE: usize = mem::size_of::<[u8; 16]>() + mem::size_of::<i16>();
+/// Size of the hashmap itself without the entrys (48 bytes)
+pub(crate) const HASH_MAP_SIZE: usize = mem::size_of::<HashMap<u8, u8>>();
+
+/// Nonce cache struct, used to store nonces for a short period of time
+/// to prevent replay attacks, each nonce has a 30 seconds lifetime.
+///
+/// The cache will remove first 10% nonces if the cache limit is reached.
+pub struct NonceCache {
+    /// The nonce cache hashmap, the key is the nonce and the value is the time
+    cache: TokioMutex<HashMap<[u8; 16], i64>>,
+}
+
+impl NonceCache {
+    /// Creates new [`NonceCache`] instance, with the given cache limit
+    pub fn new(cache_limit: &Size) -> Self {
+        Self {
+            cache: TokioMutex::new(HashMap::with_capacity(
+                (cache_limit.as_bytes() - HASH_MAP_SIZE) / NONCE_ENTRY_SIZE,
+            )),
+        }
+    }
+
+    /// Add a nonce to the cache, returns `true` if the nonce is added, `false`
+    /// if the nonce is already exist in the cache.
+    pub async fn add_nonce(&self, nonce: &[u8; 16]) -> bool {
+        let mut cache = self.cache.lock().await;
+        let now = Utc::now().timestamp();
+        cache.retain(|_, time| (now - *time) < 30);
+
+        if cache.len() == cache.capacity() {
+            log::warn!("Nonce cache limit reached, clearing 10% of the cache");
+            let num_to_remove = cache.capacity() / 10;
+            let keys: Vec<[u8; 16]> = cache.keys().copied().collect();
+            for key in keys.iter().take(num_to_remove) {
+                cache.remove(key);
+            }
+        }
+
+        // We can use insert directly, but it's will update the value if the key is
+        // already exist so we need to check if the key is already exist or not
+        if cache.contains_key(nonce) {
+            return false;
+        }
+        cache.insert(*nonce, now);
+        true
+    }
+}

crates/oxidetalis/src/routes/mod.rs

@@ -14,9 +14,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program. If not, see <https://gnu.org/licenses/agpl-3.0>.
 
-use std::collections::HashMap;
+use std::env;
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
-use std::{env, mem};
 
 use oxidetalis_config::Config;
 use salvo::http::ResBody;
@@ -24,18 +23,12 @@ use salvo::oapi::{Info, License};
 use salvo::rate_limiter::{BasicQuota, FixedGuard, MokaStore, RateLimiter, RemoteIpIssuer};
 use salvo::{catcher::Catcher, logging::Logger, prelude::*};
 
+use crate::nonce::NonceCache;
 use crate::schemas::MessageSchema;
-use crate::{middlewares, websocket, NonceCache};
+use crate::{middlewares, websocket};
 
 mod user;
 
-/// Size of each entry in the nonce cache
-pub(crate) const NONCE_ENTRY_SIZE: usize = mem::size_of::<[u8; 16]>() + mem::size_of::<i16>();
-/// Size of the hashmap itself without the entrys (48 bytes)
-pub(crate) const HASH_MAP_SIZE: usize = mem::size_of::<HashMap<u8, u8>>();
-/// Name of the nonce cache size in the depot
-pub(crate) const DEPOT_NONCE_CACHE_SIZE: &str = "NONCE_CACHE_SIZE";
-
 pub fn write_json_body(res: &mut Response, json_body: impl serde::Serialize) {
     res.write_body(serde_json::to_string(&json_body).expect("Json serialization can't be fail"))
         .ok();
@@ -69,7 +62,7 @@ async fn handle_server_errors(res: &mut Response, ctrl: &mut FlowCtrl) {
                     err.brief.trim_end_matches('.'),
                     err.cause
                         .as_deref()
-                        .map_or_else(|| "".to_owned(), ToString::to_string)
+                        .map_or_else(String::new, ToString::to_string)
                         .trim_end_matches('.')
                         .split(':')
                         .last()
@@ -129,13 +122,9 @@ fn route_openapi(config: &Config, router: Router) -> Router {
 }
 
 pub fn service(conn: sea_orm::DatabaseConnection, config: &Config) -> Service {
-    let nonce_cache_size = config.server.nonce_cache_size.as_bytes();
+    let nonce_cache: NonceCache = NonceCache::new(&config.server.nonce_cache_size);
-    let nonce_cache: NonceCache = Mutex::new(HashMap::with_capacity(
-        (nonce_cache_size - HASH_MAP_SIZE) / NONCE_ENTRY_SIZE,
-    ));
     log::info!(
-        "Nonce cache created with a capacity of {} ({})",
+        "Nonce cache created with a capacity of {}",
-        (nonce_cache_size - HASH_MAP_SIZE) / NONCE_ENTRY_SIZE,
         config.server.nonce_cache_size
     );
 
@@ -146,7 +135,6 @@ pub fn service(conn: sea_orm::DatabaseConnection, config: &Config) -> Service {
         .hoop(Logger::new())
         .hoop(
             affix::inject(Arc::new(conn))
-                .insert(DEPOT_NONCE_CACHE_SIZE, Arc::new(nonce_cache_size))
                 .inject(Arc::new(config.clone()))
                 .inject(Arc::new(nonce_cache)),
         );

crates/oxidetalis/src/utils.rs

@@ -27,7 +27,7 @@ use oxidetalis_core::{
 };
 use salvo::Request;
 
-use crate::{extensions::NonceCacheExt, NonceCache};
+use crate::nonce::NonceCache;
 
 /// Returns the postgres database url
 #[logcall]
@@ -43,16 +43,12 @@ pub(crate) fn postgres_url(db_config: &Postgres) -> String {
 }
 
 /// Returns true if the given nonce a valid nonce.
-pub(crate) fn is_valid_nonce(
+pub(crate) async fn is_valid_nonce(signature: &Signature, nonce_cache: &NonceCache) -> bool {
-    signature: &Signature,
-    nonce_cache: &NonceCache,
-    nonce_cache_limit: &usize,
-) -> bool {
     let new_timestamp = Utc::now()
         .timestamp()
         .checked_sub(u64::from_be_bytes(*signature.timestamp()) as i64)
         .is_some_and(|n| n <= 20);
-    let unused_nonce = new_timestamp && nonce_cache.add_nonce(signature.nonce(), nonce_cache_limit);
+    let unused_nonce = new_timestamp && nonce_cache.add_nonce(signature.nonce()).await;
     new_timestamp && unused_nonce
 }
 

crates/oxidetalis/src/websocket/events/client.rs

@@ -19,7 +19,7 @@
 use oxidetalis_core::types::Signature;
 use serde::{Deserialize, Serialize};
 
-use crate::{utils, NonceCache};
+use crate::{nonce::NonceCache, utils};
 
 /// Client websocket event
 #[derive(Deserialize, Clone, Debug)]
@@ -49,13 +49,12 @@ impl ClientEventType {
 
 impl ClientEvent {
     /// Verify the signature of the event
-    pub fn verify_signature(
+    pub async fn verify_signature(
         &self,
         shared_secret: &[u8; 32],
         nonce_cache: &NonceCache,
-        nonce_limit: &usize,
     ) -> bool {
-        utils::is_valid_nonce(&self.signature, nonce_cache, nonce_limit)
+        utils::is_valid_nonce(&self.signature, nonce_cache).await
             && self.signature.verify(&self.event.data(), shared_secret)
     }
 }

crates/oxidetalis/src/websocket/mod.rs

@@ -41,8 +41,8 @@ use uuid::Uuid;
 use crate::{
     extensions::{DepotExt, OnlineUsersExt},
     middlewares,
+    nonce::NonceCache,
     utils,
-    NonceCache,
 };
 
 /// Online users type
@@ -92,7 +92,6 @@ pub async fn user_connected(
     depot: &Depot,
 ) -> Result<(), StatusError> {
     let nonce_cache = depot.nonce_cache();
-    let nonce_limit = *depot.nonce_cache_size();
     let public_key =
         utils::extract_public_key(req).expect("The public key was checked in the middleware");
     // FIXME: The config should hold `K256Secret` not `PrivateKey`
@@ -101,7 +100,7 @@ pub async fn user_connected(
 
     WebSocketUpgrade::new()
         .upgrade(req, res, move |ws| {
-            handle_socket(ws, nonce_cache, nonce_limit, public_key, shared_secret)
+            handle_socket(ws, nonce_cache, public_key, shared_secret)
         })
         .await
 }
@@ -110,7 +109,6 @@ pub async fn user_connected(
 async fn handle_socket(
     ws: WebSocket,
     nonce_cache: Arc<NonceCache>,
-    nonce_limit: usize,
     user_public_key: PublicKey,
     user_shared_secret: [u8; 32],
 ) {
@@ -131,7 +129,7 @@ async fn handle_socket(
 
     let fut = async move {
         while let Some(Ok(msg)) = user_ws_receiver.next().await {
-            match handle_ws_msg(msg, &nonce_cache, &nonce_limit, &user_shared_secret) {
+            match handle_ws_msg(msg, &nonce_cache, &user_shared_secret).await {
                 Ok(event) => {
                     if let Some(server_event) = handle_events(event, &conn_id).await {
                         if let Err(err) = sender.unbounded_send(Ok(Message::from(
@@ -158,10 +156,9 @@ async fn handle_socket(
 }
 
 /// Handle websocket msg
-fn handle_ws_msg(
+async fn handle_ws_msg(
     msg: Message,
     nonce_cache: &NonceCache,
-    nonce_limit: &usize,
     shared_secret: &[u8; 32],
 ) -> WsResult<ClientEvent> {
     let Ok(text) = msg.to_str() else {
@@ -174,7 +171,7 @@ fn handle_ws_msg(
             WsError::InvalidJsonData
         }
     })?;
-    if !event.verify_signature(shared_secret, nonce_cache, nonce_limit) {
+    if !event.verify_signature(shared_secret, nonce_cache).await {
         return Err(WsError::InvalidSignature);
     }
     Ok(event)