securite: #87 T5b nonces CSP prets pour bascule (sans changement)

tests/frontend/excalidraw-viewer.test.mjs

@@ -100,7 +100,7 @@ await test("module exports renderExcalidraw + helpers", () => {
   assert.equal(typeof destroyExcalidrawEditor, "function");
 });
 
-await test("renderExcalidraw creates an iframe with sandbox + static src", () => {
+await test("renderExcalidraw creates an iframe with sandbox + routed src", () => {
   const container = document.getElementById("content-area");
   const data = {
     is_excalidraw: true,
@@ -111,7 +111,8 @@ await test("renderExcalidraw creates an iframe with sandbox + static src", () =>
   renderExcalidraw(container, data, "TestVault", "diagram.excalidraw");
   const iframe = container.querySelector("iframe");
   assert.ok(iframe, "iframe should be created");
-  assert.ok(iframe.src.includes("/static/excalidraw-editor.html"), `src: ${iframe.src}`);
+  assert.ok(iframe.src.includes("/excalidraw-editor.html"), `src: ${iframe.src}`);
+  assert.ok(!iframe.src.includes("/static/excalidraw-editor.html"), `route avec nonce CSP: ${iframe.src}`);
   assert.ok(iframe.sandbox.contains("allow-scripts"), "sandbox allow-scripts");
   assert.ok(iframe.sandbox.contains("allow-same-origin"), "sandbox allow-same-origin");
   assert.match(iframe.style.cssText, /100%/);

tests/test_csp_nonce.py

@@ -0,0 +1,82 @@
+"""Tests — nonces CSP (ROADMAP #87 T5b).
+
+- `inject_csp_nonce` ne touche que les scripts inline exécutables
+  (`<script>`, `type="module"` / `type="importmap"` sans `src`), jamais les
+  blocs de données (`type="text/plain"`) ni les scripts externes.
+- Chaque page HTML servie avec des scripts inline les porte tous avec un
+  nonce après injection.
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+NONCE = "TESTNONCE1234567890"
+
+
+def _read(name: str) -> str:
+    return (ROOT / "frontend" / name).read_text(encoding="utf-8")
+
+
+def test_inject_only_bare_executable_scripts():
+    from backend.csp import inject_csp_nonce
+
+    html = (
+        "<script>var a = 1;</script>"
+        '<script type="module">import x from "y";</script>'
+        '<script type="importmap">{"imports": {}}</script>'
+        '<script type="module" src="/static/js/app.js"></script>'
+        '<script src="https://cdnjs.cloudflare.com/x.js"></script>'
+        '<script id="raw-content" type="text/plain">hello</script>'
+        '<script nonce="OLD">var b = 2;</script>'
+    )
+    out = inject_csp_nonce(html, NONCE)
+    assert out.count(f'nonce="{NONCE}"') == 3
+    assert '<script src="https://cdnjs.cloudflare.com/x.js">' in out
+    assert '<script id="raw-content" type="text/plain">' in out
+    assert '<script nonce="OLD">' in out
+
+
+def test_new_nonce_unique_per_call():
+    from backend.csp import new_nonce
+
+    assert new_nonce() != new_nonce()
+
+
+def test_all_pages_fully_nonced():
+    """Aucun script inline exécutable sans nonce après injection (sauf src=)."""
+    from backend.csp import inject_csp_nonce
+
+    for name in ("index.html", "popout.html", "admin.html", "editor-poc.html", "excalidraw-editor.html"):
+        out = inject_csp_nonce(_read(name), NONCE)
+        bare = re.findall(r"<script>", out)
+        assert not bare, f"{name} : scripts sans nonce restants"
+        inline_mods = [m for m in re.findall(r'<script type="(?:module|importmap)">', out)]
+        assert not inline_mods, f"{name} : modules/importmap sans nonce restants"
+
+
+def _nonce_of(csp: str) -> str | None:
+    m = re.search(r"'nonce-([^']+)'", csp or "")
+    return m.group(1) if m else None
+
+
+def test_nonce_header_fresh_per_response(client):
+    """Chaque réponse porte un nonce frais dans `script-src`."""
+    r1 = client.get("/")
+    r2 = client.get("/")
+    n1, n2 = _nonce_of(r1.headers.get("content-security-policy")), _nonce_of(
+        r2.headers.get("content-security-policy")
+    )
+    assert n1 and n2 and n1 != n2
+
+
+def test_nonce_matches_injected_html(client):
+    """Le nonce de l'en-tête est celui injecté dans le HTML (`/`, excalidraw)."""
+    for path in ("/", "/excalidraw-editor.html"):
+        resp = client.get(path)
+        assert resp.status_code == 200, path
+        nonce = _nonce_of(resp.headers.get("content-security-policy"))
+        assert nonce, path
+        assert f'nonce="{nonce}"' in resp.text, path