test(http): cover TUS Upload-Length enforcement

Refs GHSA-ffv3-7h97-993q

http/tus_upload_length_test.go

@@ -0,0 +1,73 @@
+package fbhttp
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/filebrowser/filebrowser/v2/settings"
+	"github.com/filebrowser/filebrowser/v2/users"
+)
+
+// A TUS PATCH must not write more than the declared Upload-Length. A client that
+// declares a small length and then streams a large body must be rejected without
+// the excess being written to disk, while a correctly-sized upload still works.
+func TestTusPatchEnforcesUploadLength(t *testing.T) {
+	root := t.TempDir()
+	userScope := filepath.Join(root, "user")
+	if err := os.MkdirAll(userScope, 0o755); err != nil {
+		t.Fatal(err)
+	}
+
+	key := []byte("test-signing-key")
+	perm := users.Permissions{Create: true, Modify: true}
+	st := scopedUserStorage(t, userScope, perm, key)
+	signed := signToken(t, perm, key)
+
+	cache := newMemoryUploadCache()
+	t.Cleanup(cache.Close)
+	post := handle(tusPostHandler(cache), "", st, &settings.Server{})
+	patch := handle(tusPatchHandler(cache), "", st, &settings.Server{})
+
+	patchReq := func(body string) *httptest.ResponseRecorder {
+		req, _ := http.NewRequest(http.MethodPatch, "/file.txt", strings.NewReader(body))
+		req.Header.Set("X-Auth", signed)
+		req.Header.Set("Content-Type", "application/offset+octet-stream")
+		req.Header.Set("Upload-Offset", "0")
+		rec := httptest.NewRecorder()
+		patch.ServeHTTP(rec, req)
+		return rec
+	}
+
+	// Create an upload that declares only 5 bytes.
+	reqPost, _ := http.NewRequest(http.MethodPost, "/file.txt", http.NoBody)
+	reqPost.Header.Set("X-Auth", signed)
+	reqPost.Header.Set("Upload-Length", "5")
+	recPost := httptest.NewRecorder()
+	post.ServeHTTP(recPost, reqPost)
+	if recPost.Code != http.StatusCreated {
+		t.Fatalf("POST expected 201, got %d body=%q", recPost.Code, recPost.Body.String())
+	}
+
+	// A body far larger than the declared length must be rejected, and nothing
+	// beyond the declared length may reach disk.
+	if rec := patchReq(strings.Repeat("A", 5000)); rec.Code != http.StatusRequestEntityTooLarge {
+		t.Fatalf("over-length PATCH expected 413, got %d body=%q", rec.Code, rec.Body.String())
+	}
+	if fi, err := os.Stat(filepath.Join(userScope, "file.txt")); err != nil {
+		t.Fatalf("stat file.txt: %v", err)
+	} else if fi.Size() > 5 {
+		t.Fatalf("wrote %d bytes despite Upload-Length 5", fi.Size())
+	}
+
+	// A correctly-sized upload still completes.
+	if rec := patchReq("hello"); rec.Code != http.StatusNoContent {
+		t.Fatalf("valid PATCH expected 204, got %d body=%q", rec.Code, rec.Body.String())
+	}
+	if data, _ := os.ReadFile(filepath.Join(userScope, "file.txt")); string(data) != "hello" {
+		t.Fatalf("expected file content \"hello\", got %q", string(data))
+	}
+}