security: fix auth bypass and CORS misconfiguration (V-008, V-009)

API Server security hardening:

V-009 (CVSS 8.1) - Authentication Bypass Fix:
- Changed default from allow-all to deny-all when no API key configured
- Added explicit API_SERVER_ALLOW_UNAUTHENTICATED setting for local dev
- Added warning logs for both secure and insecure configurations

V-008 (CVSS 8.2) - CORS Misconfiguration Fix:
- Reject wildcard '*' CORS origins (security vulnerability with credentials)
- Require explicit origin configuration
- Added warning log when wildcard detected

Changes:
- gateway/platforms/api_server.py: Hardened auth and CORS handling

Refs: V-008, V-009 in SECURITY_AUDIT_REPORT.md
CWE-287: Improper Authentication
CWE-942: Permissive Cross-domain Policy

gateway/platforms/api_server.py

@@ -292,7 +292,29 @@ class APIServerAdapter(BasePlatformAdapter):
         extra = config.extra or {}
         self._host: str = extra.get("host", os.getenv("API_SERVER_HOST", DEFAULT_HOST))
         self._port: int = int(extra.get("port", os.getenv("API_SERVER_PORT", str(DEFAULT_PORT))))
+        
+        # SECURITY FIX (V-009): Fail-secure default for API key
+        # Previously: Empty API key allowed all requests (dangerous default)
+        # Now: Require explicit "allow_unauthenticated" setting to disable auth
         self._api_key: str = extra.get("key", os.getenv("API_SERVER_KEY", ""))
+        self._allow_unauthenticated: bool = extra.get(
+            "allow_unauthenticated", 
+            os.getenv("API_SERVER_ALLOW_UNAUTHENTICATED", "").lower() in ("true", "1", "yes")
+        )
+        
+        # SECURITY: Log warning if no API key configured
+        if not self._api_key and not self._allow_unauthenticated:
+            logger.warning(
+                "API_SERVER_KEY not configured. All requests will be rejected. "
+                "Set API_SERVER_ALLOW_UNAUTHENTICATED=true for local-only use, "
+                "or configure API_SERVER_KEY for production."
+            )
+        elif not self._api_key and self._allow_unauthenticated:
+            logger.warning(
+                "API_SERVER running without authentication. "
+                "This is only safe for local-only deployments."
+            )
+        
         self._cors_origins: tuple[str, ...] = self._parse_cors_origins(
             extra.get("cors_origins", os.getenv("API_SERVER_CORS_ORIGINS", "")),
         )
@@ -317,15 +339,22 @@ class APIServerAdapter(BasePlatformAdapter):
         return tuple(str(item).strip() for item in items if str(item).strip())
 
     def _cors_headers_for_origin(self, origin: str) -> Optional[Dict[str, str]]:
-        """Return CORS headers for an allowed browser origin."""
+        """Return CORS headers for an allowed browser origin.
+        
+        SECURITY FIX (V-008): Never allow wildcard "*" with credentials.
+        If "*" is configured, we reject the request to prevent security issues.
+        """
         if not origin or not self._cors_origins:
             return None
 
+        # SECURITY FIX (V-008): Reject wildcard CORS origins
+        # Wildcard with credentials is a security vulnerability
         if "*" in self._cors_origins:
-            headers = dict(_CORS_HEADERS)
+            logger.warning(
-            headers["Access-Control-Allow-Origin"] = "*"
+                "CORS wildcard '*' is not allowed for security reasons. "
-            headers["Access-Control-Max-Age"] = "600"
+                "Please configure specific origins in API_SERVER_CORS_ORIGINS."
-            return headers
+            )
+            return None  # Reject wildcard - too dangerous
 
         if origin not in self._cors_origins:
             return None
@@ -355,10 +384,22 @@ class APIServerAdapter(BasePlatformAdapter):
         Validate Bearer token from Authorization header.
 
         Returns None if auth is OK, or a 401 web.Response on failure.
-        If no API key is configured, all requests are allowed.
+        
+        SECURITY FIX (V-009): Fail-secure default
+        - If no API key is configured AND allow_unauthenticated is not set,
+          all requests are rejected (secure by default)
+        - Only allow unauthenticated requests if explicitly configured
         """
-        if not self._api_key:
+        # SECURITY: Fail-secure default - reject if no key and not explicitly allowed
-            return None  # No key configured — allow all (local-only use)
+        if not self._api_key and not self._allow_unauthenticated:
+            return web.json_response(
+                {"error": {"message": "Authentication required. Configure API_SERVER_KEY or set API_SERVER_ALLOW_UNAUTHENTICATED=true for local development.", "type": "authentication_error", "code": "auth_required"}},
+                status=401,
+            )
+        
+        # Allow unauthenticated requests only if explicitly configured
+        if not self._api_key and self._allow_unauthenticated:
+            return None  # Explicitly allowed for local-only use
 
         auth_header = request.headers.get("Authorization", "")
         if auth_header.startswith("Bearer "):