Expand Firebase Storage rules coverage and skill discovery

docs/advanced/skills.mdx

@@ -71,7 +71,7 @@ Third-party service and platform security.
 | Skill                | Coverage                           |
 | -------------------- | ---------------------------------- |
 | `supabase`           | Supabase RLS bypasses, auth issues |
-| `firebase_firestore` | Firestore rules, Firebase auth     |
+| `firebase` | Firebase Firestore, Storage rules, Auth, and Functions |
 
 ### Protocols
 

strix/agents/prompts/system_prompt.jinja

@@ -490,8 +490,10 @@ Default user: pentester (sudo available)
 <available_skills>
 On-demand specialist skills. Spawn a specialist via `create_agent(skills=[...])`, or pull guidance inline for yourself via `load_skill(skills=[...])`. Anything wrapped in `<specialized_knowledge>` above is already loaded for you.
 
-{% for category, names in available_skills | dictsort -%}
-- {{ category }}: {{ names | join(', ') }}
+{% for category, skills in available_skills | dictsort -%}
+{% for skill in skills -%}
+- {{ category }}/{{ skill.name }}: {{ skill.description }}
+{% endfor -%}
 {% endfor -%}
 </available_skills>
 {% endif %}

strix/skills/__init__.py

@@ -145,10 +145,25 @@ def _bare_skill_files(skill_name: str) -> list[Path]:
     return candidates
 
 
-def get_available_skills() -> dict[str, list[str]]:
-    grouped: dict[str, list[str]] = {}
+def _skill_description(file_path: Path) -> str:
+    try:
+        content = file_path.read_text(encoding="utf-8")
+    except (OSError, ValueError):
+        return ""
+    frontmatter = _FRONTMATTER_PATTERN.match(content)
+    if frontmatter is None:
+        return ""
+    match = re.search(r"^description:\s*(.+?)\s*$", frontmatter.group(0), re.MULTILINE)
+    return match.group(1).strip() if match else ""
+
+
+def get_available_skills() -> dict[str, list[dict[str, str]]]:
+    grouped: dict[str, list[dict[str, str]]] = {}
     for category, name in _iter_user_skill_files():
-        grouped.setdefault(category, []).append(name)
+        path = _qualified_skill_files(f"{category}/{name}")
+        grouped.setdefault(category, []).append(
+            {"name": name, "description": _skill_description(path[0]) if path else ""}
+        )
     return grouped
 
 

strix/skills/cloud/gcp.md

@@ -16,7 +16,7 @@ GCP misconfigurations expose project data, service account keys, and lateral mov
 
 **Storage & Data**
 - Cloud Storage (GCS) buckets and objects
-- BigQuery datasets, Cloud SQL instances, Firestore (see `firebase_firestore` skill)
+- BigQuery datasets, Cloud SQL instances, Firestore (see `firebase` skill)
 - Secret Manager, Cloud KMS keys
 
 **Compute**

strix/skills/technologies/firebase.md

@@ -1,9 +1,9 @@
 ---
-name: firebase-firestore
-description: Firebase/Firestore security testing covering security rules, Cloud Functions, and client-side trust issues
+name: firebase
+description: Firebase security testing covering Firestore, Storage rules, Realtime Database, Auth, Functions, and client-side trust issues
 ---
 
-# Firebase / Firestore
+# Firebase
 
 Security testing for Firebase applications. Focus on Firestore/Realtime Database rules, Cloud Storage exposure, callable/onRequest Functions trusting client input, and incorrect ID token validation.
 
@@ -30,7 +30,17 @@ Security testing for Firebase applications. Focus on Firestore/Realtime Database
 **Endpoints**
 - Firestore REST: `https://firestore.googleapis.com/v1/projects/<project>/databases/(default)/documents/<path>`
 - Realtime DB: `https://<project>.firebaseio.com/.json`
-- Storage REST: `https://storage.googleapis.com/storage/v1/b/<bucket>`
+- GCS JSON API: `https://storage.googleapis.com/storage/v1/b/<bucket>`
+- Firebase Storage rules API: `https://firebasestorage.googleapis.com/v0/b/<bucket>/o`
+
+Cloud Storage has two front doors with different authorization engines:
+
+| Front door | Authorization engine |
+| --- | --- |
+| `storage.googleapis.com/<bucket>/<object>` and `/storage/v1/b/<bucket>` | GCS IAM and per-object ACLs |
+| `firebasestorage.googleapis.com/v0/b/<bucket>/o` | Firebase Storage Security Rules |
+
+A `403` from a GCS URL does not prove that Firebase Storage rules deny access. Always test both doors.
 
 **Auth**
 - Google-signed ID tokens (iss: `accounts.google.com` or `securetoken.google.com/<project>`)
@@ -117,9 +127,44 @@ exists(/databases/(default)/documents/orgs/$(org)/members/$(request.auth.uid))
 - Public reads on sensitive buckets/paths
 - Signed URLs with long TTL, no content-disposition controls, replayable across tenants
 - List operations exposed: `/o?prefix=` enumerates object keys
+- Firebase Storage rules allowing unauthenticated or overly broad reads and writes
+
+**Firebase Storage rules checks**
+
+Probe the rules door separately from GCS IAM and ACLs:
+
+1. Unauthenticated list: `GET https://firebasestorage.googleapis.com/v0/b/<bucket>/o?prefix=<known-prefix>`
+2. Unauthenticated read of a known object path
+3. Unauthenticated write/upload to a uniquely named test object
+4. Repeat list, read, and write as an anonymous-auth principal when anonymous sign-in is enabled
+5. Repeat the same matrix as a low-privilege authenticated user
+
+Write access is as important as read access and is routinely missed. Record status, response body, and object existence after each attempt; clean up only test objects that the test principal created.
+
+Review rules source when present and flag:
+
+- `allow read, write: if request.time < timestamp.date(...)` — the common console test-mode time gate
+- `{allPaths=**}` catch-alls
+- `request.auth != null` as the sole authorization gate
+- Claim-presence checks such as `request.auth.token.roles.size() > 0` without role or tenant validation
+
+Storage rules use OR-across-matches semantics: a later permissive match can reopen a path that an earlier match denied. Review every matching path, not only the most specific-looking deny.
+
+**Bucket discovery**
+
+- Extract `storageBucket` from `firebase.apps[0].options` and `NEXT_PUBLIC_FIREBASE_*` values in JavaScript bundles and source.
+- Check `<project>.appspot.com` and `<project>.firebasestorage.app` bucket conventions.
+
+**ACL and IAM checks are separate**
+
+- Sweep object ACLs for `allUsers` and `allAuthenticatedUsers`, including objects made public by Admin SDK `makePublic()` or writers using `public: true`. Per-object public ACLs persist after Firebase rules are tightened and can remain on older prefixes.
+- Check bucket IAM for `allUsers` and `allAuthenticatedUsers`.
+- Check whether Uniform Bucket-Level Access is disabled; legacy object ACLs matter when it is off.
+- Account for CDN caching of previously public objects; cache-bust when verifying a revocation.
 
 **Tests**
-- GET gs:// paths via HTTPS without auth; verify Content-Type and `Content-Disposition: attachment`
+- GET GCS object paths via HTTPS without auth; verify Content-Type and `Content-Disposition: attachment`
+- Test the Firebase Storage list/read/write matrix above with each available principal
 - Generate and reuse signed URLs across accounts and paths; try case/URL-encoding variants
 - Upload HTML/SVG and verify `X-Content-Type-Options: nosniff`; check for script execution
 
@@ -189,12 +234,19 @@ Apps often implement multi-tenant data models (`orgs/<orgId>/...`). Bind tenant
 
 ## Testing Methodology
 
-1. **Extract config** - Get project config from client bundle
-2. **Obtain principals** - Collect tokens for unauth, anonymous, user A/B, admin
+1. **Extract config** - Get project and storage bucket config from client bundles and source
+2. **Obtain principals** - Collect tokens for unauth, anonymous, user A/B, and admin where authorized
 3. **Build matrix** - Resource × Action × Principal across Firestore/Realtime/Storage/Functions
-4. **SDK vs REST** - Exercise every action via both to detect parity gaps
-5. **Seed IDs** - Start from list/query paths to gather document IDs
-6. **Cross-principal** - Swap document paths, tenants, and user IDs across principals
+4. **Exercise both Storage doors** - Test Firebase Storage rules endpoints separately from GCS IAM/ACL URLs
+5. **SDK vs REST** - Exercise every action via both to detect parity gaps
+6. **Seed IDs** - Start from list/query paths to gather document and object paths
+7. **Cross-principal** - Swap document paths, tenants, and user IDs across principals
+
+## Whitebox Rules Review
+
+- Inspect `firebase.json`, `.firebaserc`, deployment scripts, CI configuration, and infrastructure code for `storage.rules` / `firestore.rules` declarations.
+- If `firebase.json` has no `storage` or `firestore` block, or the referenced rules file is absent from the tree, treat the live rules as unmanaged and force the live probe matrix. Absence of rules IaC is itself a finding; never conclude that there is nothing to review.
+- Correlate configured rule files with deployed project and bucket identifiers. A source rule file for a different project does not establish live protection.
 
 ## Tooling
 
@@ -206,6 +258,7 @@ Apps often implement multi-tenant data models (`orgs/<orgId>/...`). Bind tenant
 ## Validation Requirements
 
 - Owner vs non-owner Firestore queries showing unauthorized access or metadata leak
-- Cloud Storage read/write beyond intended scope (public object, signed URL reuse, list exposure)
+- Firebase Storage unauthenticated, anonymous, or low-privilege read/list/write beyond intended scope, with minimal reproducible requests and observed deltas
+- GCS object ACL or bucket IAM access beyond intended scope, including public object persistence after rules changes
 - Function accepting forged/foreign identity (wrong `aud`/`iss`) or trusting client `uid`/`orgId`
 - Minimal reproducible requests with roles/tokens used and observed deltas

tests/test_skill_dir_extension.py

@@ -1,8 +1,10 @@
+from collections.abc import Iterator
 from pathlib import Path
 
 import pytest
 
 import strix.skills as skills_mod
+from strix.agents.prompt import render_system_prompt
 from strix.skills import (
     get_all_skill_names,
     get_available_skills,
@@ -12,10 +14,11 @@ from strix.skills import (
     skill_search_dirs,
     validate_requested_skills,
 )
+from strix.utils.resource_paths import get_strix_resource_path
 
 
 @pytest.fixture(autouse=True)
-def _clear_extra_dirs() -> None:
+def _clear_extra_dirs() -> Iterator[None]:
     original = list(skills_mod._EXTRA_SKILL_DIRS)
     skills_mod._EXTRA_SKILL_DIRS.clear()
     try:
@@ -37,9 +40,11 @@ def _write_root_skill(root: Path, name: str, body: str) -> None:
 
 def test_no_registration_leaves_builtin_only() -> None:
     assert registered_skill_dirs() == ()
-    builtin = skills_mod.get_strix_resource_path("skills")
+    builtin = get_strix_resource_path("skills")
     assert skill_search_dirs() == (builtin,)
-    assert {"nmap", "subfinder"}.issubset(get_available_skills()["tooling"])
+    assert {"nmap", "subfinder"}.issubset(
+        {skill["name"] for skill in get_available_skills()["tooling"]}
+    )
 
 
 def test_register_is_idempotent_and_ordered(tmp_path: Path) -> None:
@@ -61,16 +66,36 @@ def test_registered_dir_adds_new_skill(tmp_path: Path) -> None:
     register_skill_dir(tmp_path)
 
     assert "widget" in get_all_skill_names()
-    assert get_available_skills()["extra"] == ["widget"]
+    assert get_available_skills()["extra"] == [{"name": "widget", "description": ""}]
     assert load_skills(["widget"]) == {"widget": "widget body"}
 
 
+def test_available_skill_includes_frontmatter_description(tmp_path: Path) -> None:
+    _write_skill(
+        tmp_path,
+        "extra",
+        "widget",
+        "---\nname: widget\ndescription: Useful widget guidance\n---\nwidget body",
+    )
+    register_skill_dir(tmp_path)
+
+    assert get_available_skills()["extra"] == [
+        {"name": "widget", "description": "Useful widget guidance"}
+    ]
+
+
+def test_system_prompt_renders_skill_descriptions() -> None:
+    prompt = render_system_prompt(scan_mode="quick", is_root=True)
+
+    assert "- technologies/firebase: Firebase security testing covering" in prompt
+
+
 def test_registered_root_skill_is_discoverable_and_valid(tmp_path: Path) -> None:
     _write_root_skill(tmp_path, "widget", "widget body")
     register_skill_dir(tmp_path)
 
     assert "widget" in get_all_skill_names()
-    assert get_available_skills()["root"] == ["widget"]
+    assert get_available_skills()["root"] == [{"name": "widget", "description": ""}]
     assert validate_requested_skills(["widget"]) is None
     assert validate_requested_skills(["root/widget"]) is None
     assert load_skills(["widget"]) == {"widget": "widget body"}
@@ -83,8 +108,8 @@ def test_ambiguous_bare_skill_requires_qualified_name(tmp_path: Path) -> None:
     register_skill_dir(tmp_path)
 
     assert "widget" in get_all_skill_names()
-    assert get_available_skills()["alpha"] == ["widget"]
-    assert get_available_skills()["beta"] == ["widget"]
+    assert get_available_skills()["alpha"] == [{"name": "widget", "description": ""}]
+    assert get_available_skills()["beta"] == [{"name": "widget", "description": ""}]
     assert validate_requested_skills(["alpha/widget"]) is None
     assert validate_requested_skills(["beta/widget"]) is None