Reject all absolute paths

CHANGELOG.md

@@ -82,6 +82,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed missing path validation in `Filestore` that allowed clients to escape
   their namespace ([#65]).
 - wrap_key: Don't replace associated data with an empty array
+- Fixed `ClientFilestore` to reject paths starting with `/`
 
 ### Removed
 

src/store/filestore.rs

@@ -53,7 +53,7 @@ impl<S: Store> ClientFilestore<S> {
     /// Client files are store below `/<client_id>/dat/`.
     pub fn actual_path(&self, client_path: &Path) -> Result<PathBuf> {
         // Clients must not escape their namespace
-        if client_path.as_ref().contains("..") {
+        if client_path.as_str().contains("..") || client_path.as_str().starts_with("/") {
             return Err(Error::InvalidPath);
         }
 
@@ -514,3 +514,33 @@ impl<S: Store> Filestore for ClientFilestore<S> {
         Ok(path)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn actual_path_root() {
+        let client_path = path!("/testclient");
+        struct DummyStore;
+        impl Store for DummyStore {
+            fn ifs(&self) -> &dyn DynFilesystem {
+                panic!()
+            }
+            fn efs(&self) -> &dyn DynFilesystem {
+                panic!()
+            }
+            fn vfs(&self) -> &dyn DynFilesystem {
+                panic!()
+            }
+        }
+
+        let filestore = ClientFilestore {
+            base: PathBuf::from_path(client_path),
+            store: DummyStore,
+        };
+
+        assert!(filestore.actual_path(path!("/")).is_err());
+        assert!(filestore.actual_path(path!("/test")).is_err());
+    }
+}

tests/filesystem.rs

@@ -55,6 +55,17 @@ fn escape_namespace_root() {
     })
 }
 
+#[test]
+fn escape_namespace_root_only() {
+    client::get(|client| {
+        let key = syscall!(client.generate_key(Mechanism::P256, StorageAttributes::new())).key;
+        let mut path = PathBuf::from(path!("/"));
+        path.push(path!("sec"));
+        path.push(&key.legacy_hex_path());
+        assert!(try_syscall!(client.read_file(Location::Volatile, path)).is_err());
+    })
+}
+
 fn iterating(location: Location) {
     client::get(|client| {
         syscall!(client.write_file(