DATA
6de0bf9f5b
Vendored deer-flow upstream (bytedance/deer-flow) plus prompt-injection hardening: - New deerflow.security package: content_delimiter, html_cleaner, sanitizer (8 layers — invisible chars, control chars, symbols, NFC, PUA, tag chars, horizontal whitespace collapse with newline/tab preservation, length cap) - New deerflow.community.searx package: web_search, web_fetch, image_search backed by a private SearX instance, every external string sanitized and wrapped in <<<EXTERNAL_UNTRUSTED_CONTENT>>> delimiters - All native community web providers (ddg_search, tavily, exa, firecrawl, jina_ai, infoquest, image_search) replaced with hard-fail stubs that raise NativeWebToolDisabledError at import time, so a misconfigured tool.use path fails loud rather than silently falling back to unsanitized output - Native client back-doors (jina_client.py, infoquest_client.py) stubbed too - Native-tool tests quarantined under tests/_disabled_native/ (collect_ignore_glob via local conftest.py) - Sanitizer Layer 7 fix: only collapse horizontal whitespace, preserve newlines and tabs so list/table structure survives - Hardened runtime config.yaml references only the searx-backed tools - Factory overlay (backend/) kept in sync with deer-flow tree as a reference / source See HARDENING.md for the full audit trail and verification steps.
99 lines
4.3 KiB
Python
99 lines
4.3 KiB
Python
"""GuardrailMiddleware - evaluates tool calls against a GuardrailProvider before execution."""
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import logging
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from collections.abc import Awaitable, Callable
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from datetime import UTC, datetime
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from typing import override
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from langchain.agents import AgentState
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from langchain.agents.middleware import AgentMiddleware
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from langchain_core.messages import ToolMessage
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from langgraph.errors import GraphBubbleUp
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from langgraph.prebuilt.tool_node import ToolCallRequest
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from langgraph.types import Command
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from deerflow.guardrails.provider import GuardrailDecision, GuardrailProvider, GuardrailReason, GuardrailRequest
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logger = logging.getLogger(__name__)
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class GuardrailMiddleware(AgentMiddleware[AgentState]):
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"""Evaluate tool calls against a GuardrailProvider before execution.
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Denied calls return an error ToolMessage so the agent can adapt.
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If the provider raises, behavior depends on fail_closed:
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- True (default): block the call
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- False: allow it through with a warning
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"""
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def __init__(self, provider: GuardrailProvider, *, fail_closed: bool = True, passport: str | None = None):
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self.provider = provider
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self.fail_closed = fail_closed
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self.passport = passport
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def _build_request(self, request: ToolCallRequest) -> GuardrailRequest:
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return GuardrailRequest(
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tool_name=str(request.tool_call.get("name", "")),
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tool_input=request.tool_call.get("args", {}),
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agent_id=self.passport,
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timestamp=datetime.now(UTC).isoformat(),
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)
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def _build_denied_message(self, request: ToolCallRequest, decision: GuardrailDecision) -> ToolMessage:
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tool_name = str(request.tool_call.get("name", "unknown_tool"))
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tool_call_id = str(request.tool_call.get("id", "missing_id"))
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reason_text = decision.reasons[0].message if decision.reasons else "blocked by guardrail policy"
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reason_code = decision.reasons[0].code if decision.reasons else "oap.denied"
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return ToolMessage(
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content=f"Guardrail denied: tool '{tool_name}' was blocked ({reason_code}). Reason: {reason_text}. Choose an alternative approach.",
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tool_call_id=tool_call_id,
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name=tool_name,
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status="error",
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)
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@override
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def wrap_tool_call(
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self,
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request: ToolCallRequest,
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handler: Callable[[ToolCallRequest], ToolMessage | Command],
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) -> ToolMessage | Command:
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gr = self._build_request(request)
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try:
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decision = self.provider.evaluate(gr)
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except GraphBubbleUp:
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# Preserve LangGraph control-flow signals (interrupt/pause/resume).
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raise
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except Exception:
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logger.exception("Guardrail provider error (sync)")
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if self.fail_closed:
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decision = GuardrailDecision(allow=False, reasons=[GuardrailReason(code="oap.evaluator_error", message="guardrail provider error (fail-closed)")])
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else:
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return handler(request)
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if not decision.allow:
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logger.warning("Guardrail denied: tool=%s policy=%s code=%s", gr.tool_name, decision.policy_id, decision.reasons[0].code if decision.reasons else "unknown")
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return self._build_denied_message(request, decision)
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return handler(request)
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@override
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async def awrap_tool_call(
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self,
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request: ToolCallRequest,
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handler: Callable[[ToolCallRequest], Awaitable[ToolMessage | Command]],
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) -> ToolMessage | Command:
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gr = self._build_request(request)
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try:
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decision = await self.provider.aevaluate(gr)
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except GraphBubbleUp:
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# Preserve LangGraph control-flow signals (interrupt/pause/resume).
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raise
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except Exception:
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logger.exception("Guardrail provider error (async)")
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if self.fail_closed:
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decision = GuardrailDecision(allow=False, reasons=[GuardrailReason(code="oap.evaluator_error", message="guardrail provider error (fail-closed)")])
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else:
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return await handler(request)
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if not decision.allow:
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logger.warning("Guardrail denied: tool=%s policy=%s code=%s", gr.tool_name, decision.policy_id, decision.reasons[0].code if decision.reasons else "unknown")
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return self._build_denied_message(request, decision)
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return await handler(request)
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