path validation

crates/lanspread-peer/src/lib.rs

@@ -1,5 +1,6 @@
 #![allow(clippy::missing_errors_doc)]
 
+mod path_validation;
 mod peer;
 
 use std::{
@@ -32,7 +33,10 @@ use tokio::{
 };
 use uuid::Uuid;
 
-use crate::peer::{send_game_file_chunk, send_game_file_data};
+use crate::{
+    path_validation::validate_game_file_path,
+    peer::{send_game_file_chunk, send_game_file_data},
+};
 
 /// Initialize and start the peer system
 /// This function replaces the main.rs entry point and allows the peer to be started from other crates
@@ -348,11 +352,13 @@ async fn prepare_game_storage(
     file_descs: &[GameFileDescription],
 ) -> eyre::Result<()> {
     for desc in file_descs {
-        let path = games_folder.join(&desc.relative_path);
+        // Validate the path to prevent directory traversal
+        let validated_path = validate_game_file_path(games_folder, &desc.relative_path)?;
+
         if desc.is_dir {
-            tokio::fs::create_dir_all(&path).await?;
+            tokio::fs::create_dir_all(&validated_path).await?;
         } else {
-            if let Some(parent) = path.parent() {
+            if let Some(parent) = validated_path.parent() {
                 tokio::fs::create_dir_all(parent).await?;
             }
             let file_size = desc.file_size().unwrap_or(0);
@@ -360,7 +366,7 @@ async fn prepare_game_storage(
                 .create(true)
                 .truncate(true)
                 .write(true)
-                .open(&path)
+                .open(&validated_path)
                 .await?;
             file.set_len(file_size).await?;
         }
@@ -450,12 +456,13 @@ async fn download_chunk(
 
     tx.close().await?;
 
-    let path = base_dir.join(&chunk.relative_path);
+    // Validate the path to prevent directory traversal
+    let validated_path = validate_game_file_path(base_dir, &chunk.relative_path)?;
     let mut file = OpenOptions::new()
         .create(true)
         .write(true)
         .truncate(false)
-        .open(&path)
+        .open(&validated_path)
         .await?;
     if chunk.length == 0 && chunk.offset == 0 {
         // fallback-to-whole-file path replaces any existing partial data
@@ -493,7 +500,7 @@ async fn download_chunk(
     file.flush().await?;
 
     // Verify file integrity by checking the file size
-    verify_chunk_integrity(&path, chunk.offset, chunk.length).await?;
+    verify_chunk_integrity(&validated_path, chunk.offset, chunk.length).await?;
 
     Ok(())
 }
@@ -534,12 +541,13 @@ async fn download_whole_file(
         .await?;
     tx.close().await?;
 
-    let path = base_dir.join(&desc.relative_path);
+    // Validate the path to prevent directory traversal
+    let validated_path = validate_game_file_path(base_dir, &desc.relative_path)?;
     let mut file = OpenOptions::new()
         .create(true)
         .truncate(true)
         .write(true)
-        .open(&path)
+        .open(&validated_path)
         .await?;
     file.seek(std::io::SeekFrom::Start(0)).await?;