molecule-core/workspace/a2a_tools.py
Molecule AI Marketing Lead e00797ba35 fix(security): prevent cross-tenant memory contamination in commit_memory/recall_memory (GH#1610)
Two critical gaps in a2a_tools.py let any tenant workspace poison org-wide
(GLOBAL) memory and bypass all RBAC enforcement:

1. tool_commit_memory had no RBAC check — any agent could write any scope.
2. tool_commit_memory had no root-workspace enforcement for GLOBAL scope —
   Tenant A could POST scope=GLOBAL and pollute the shared memory store
   that Tenant B's agent reads as trusted context.

Fix adds:
- _ROLE_PERMISSIONS table (mirrors builtin_tools/audit.py) so a2a_tools
  has isolated RBAC logic without depending on memory.py.
- _check_memory_write_permission() / _check_memory_read_permission() helpers:
  evaluate RBAC roles from WorkspaceConfig; fail closed (deny) on errors.
- _is_root_workspace() / _get_workspace_tier(): read WorkspaceConfig.tier
  (0 = root/org, 1+ = tenant) from config.yaml; fall back to
  WORKSPACE_TIER env var.
- tool_commit_memory now (a) checks memory.write RBAC, (b) rejects
  GLOBAL scope for non-root workspaces, (c) embeds workspace_id in the
  POST body so the platform can namespace-isolate and audit cross-workspace
  writes.
- tool_recall_memory now checks memory.read RBAC before any HTTP call,
  and always sends workspace_id as a GET param for platform cross-validation.

Security regression tests added:
- GLOBAL scope denied for non-root (tier>0) workspaces.
- RBAC denial blocks all scope levels (including LOCAL) on write.
- RBAC denial blocks recall entirely.
- workspace_id present in POST body and GET params.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-23 10:21:34 -07:00

397 lines
15 KiB
Python

"""A2A MCP tool implementations — the body of each tool handler.
Imports shared client functions and constants from a2a_client.
"""
import hashlib
import json
import os
import uuid
import httpx
from a2a_client import (
PLATFORM_URL,
WORKSPACE_ID,
_A2A_ERROR_PREFIX,
_peer_names,
discover_peer,
get_peers,
get_workspace_info,
send_a2a_message,
)
from builtin_tools.security import _redact_secrets
# ---------------------------------------------------------------------------
# RBAC helpers (mirror builtin_tools/audit.py for a2a_tools isolation)
# ---------------------------------------------------------------------------
_ROLE_PERMISSIONS = {
"admin": {"delegate", "approve", "memory.read", "memory.write"},
"operator": {"delegate", "approve", "memory.read", "memory.write"},
"read-only": {"memory.read"},
"no-delegation": {"approve", "memory.read", "memory.write"},
"no-approval": {"delegate", "memory.read", "memory.write"},
"memory-readonly": {"memory.read"},
}
def _get_workspace_tier() -> int:
"""Return the workspace tier from config (0 = root, 1+ = tenant)."""
try:
from config import load_config
cfg = load_config()
return getattr(cfg, "tier", 1)
except Exception:
return int(os.environ.get("WORKSPACE_TIER", 1))
def _check_memory_write_permission() -> bool:
"""Return True if this workspace's RBAC roles grant memory.write."""
try:
from config import load_config
cfg = load_config()
roles = list(getattr(cfg, "rbac", None).roles or ["operator"])
allowed = dict(getattr(cfg, "rbac", None).allowed_actions or {})
except Exception:
# Fail closed: deny when config is unavailable
roles = ["operator"]
allowed = {}
for role in roles:
if role == "admin":
return True
if role in allowed:
if "memory.write" in allowed[role]:
return True
elif role in _ROLE_PERMISSIONS and "memory.write" in _ROLE_PERMISSIONS[role]:
return True
return False
def _check_memory_read_permission() -> bool:
"""Return True if this workspace's RBAC roles grant memory.read."""
try:
from config import load_config
cfg = load_config()
roles = list(getattr(cfg, "rbac", None).roles or ["operator"])
allowed = dict(getattr(cfg, "rbac", None).allowed_actions or {})
except Exception:
roles = ["operator"]
allowed = {}
for role in roles:
if role == "admin":
return True
if role in allowed:
if "memory.read" in allowed[role]:
return True
elif role in _ROLE_PERMISSIONS and "memory.read" in _ROLE_PERMISSIONS[role]:
return True
return False
def _is_root_workspace() -> bool:
"""Return True if this workspace is tier 0 (root/root-org)."""
return _get_workspace_tier() == 0
def _auth_headers_for_heartbeat() -> dict[str, str]:
"""Return Phase 30.1 auth headers; tolerate platform_auth being absent
in older installs (e.g. during rolling upgrade)."""
try:
from platform_auth import auth_headers
return auth_headers()
except Exception:
return {}
async def report_activity(
activity_type: str, target_id: str = "", summary: str = "", status: str = "ok",
task_text: str = "", response_text: str = "",
):
"""Report activity to the platform for live progress tracking."""
try:
async with httpx.AsyncClient(timeout=5.0) as client:
payload: dict = {
"activity_type": activity_type,
"source_id": WORKSPACE_ID,
"target_id": target_id,
"method": "message/send",
"summary": summary,
"status": status,
}
if task_text:
payload["request_body"] = {"task": task_text}
if response_text:
payload["response_body"] = {"result": response_text}
await client.post(
f"{PLATFORM_URL}/workspaces/{WORKSPACE_ID}/activity",
json=payload,
headers=_auth_headers_for_heartbeat(),
)
# Also push current_task via heartbeat for canvas card display
if summary:
await client.post(
f"{PLATFORM_URL}/registry/heartbeat",
json={
"workspace_id": WORKSPACE_ID,
"current_task": summary,
"active_tasks": 1,
"error_rate": 0,
"sample_error": "",
"uptime_seconds": 0,
},
headers=_auth_headers_for_heartbeat(),
)
except Exception:
pass # Best-effort — don't block delegation on activity reporting
async def tool_delegate_task(workspace_id: str, task: str) -> str:
"""Delegate a task to another workspace via A2A (synchronous — waits for response)."""
if not workspace_id or not task:
return "Error: workspace_id and task are required"
# Discover the target
peer = await discover_peer(workspace_id)
if not peer:
return f"Error: workspace {workspace_id} not found or not accessible (check access control)"
target_url = peer.get("url", "")
if not target_url:
return f"Error: workspace {workspace_id} has no URL (may be offline)"
# Report delegation start — include the task text for traceability
peer_name = peer.get("name") or _peer_names.get(workspace_id) or workspace_id[:8]
_peer_names[workspace_id] = peer_name # cache for future use
# Brief summary for canvas display — just the delegation target
await report_activity("a2a_send", workspace_id, f"Delegating to {peer_name}", task_text=task)
# Send A2A message and log the full round-trip
result = await send_a2a_message(target_url, task)
# Detect delegation failures — wrap them clearly so the calling agent
# can decide to retry, use another peer, or handle the task itself.
is_error = result.startswith(_A2A_ERROR_PREFIX)
await report_activity(
"a2a_receive", workspace_id,
f"{peer_name} responded ({len(result)} chars)" if not is_error else f"{peer_name} failed",
task_text=task, response_text=result,
status="error" if is_error else "ok",
)
if is_error:
return (
f"DELEGATION FAILED to {peer_name}: {result}\n"
f"You should either: (1) try a different peer, (2) handle this task yourself, "
f"or (3) inform the user that {peer_name} is unavailable and provide your best answer."
)
return result
async def tool_delegate_task_async(workspace_id: str, task: str) -> str:
"""Delegate a task via the platform's async delegation API (fire-and-forget).
Uses POST /workspaces/:id/delegate which runs the A2A request in the background.
Results are tracked in the platform DB and broadcast via WebSocket.
Use check_task_status to poll for results.
"""
if not workspace_id or not task:
return "Error: workspace_id and task are required"
# Idempotency key: SHA-256 of (workspace_id, task) so that a restarted agent
# firing the same delegation gets the same key and the platform returns the
# existing delegation_id instead of creating a duplicate. Fixes #1456.
idem_key = hashlib.sha256(f"{workspace_id}:{task}".encode()).hexdigest()[:32]
try:
async with httpx.AsyncClient(timeout=10.0) as client:
resp = await client.post(
f"{PLATFORM_URL}/workspaces/{WORKSPACE_ID}/delegate",
json={"target_id": workspace_id, "task": task, "idempotency_key": idem_key},
headers=_auth_headers_for_heartbeat(),
)
if resp.status_code == 202:
data = resp.json()
return json.dumps({
"delegation_id": data.get("delegation_id", ""),
"workspace_id": workspace_id,
"status": "delegated",
"note": "Task delegated. The platform runs it in the background. Use check_task_status to poll for results.",
})
else:
return f"Error: delegation failed with status {resp.status_code}: {resp.text[:200]}"
except Exception as e:
return f"Error: delegation failed — {e}"
async def tool_check_task_status(workspace_id: str, task_id: str) -> str:
"""Check delegations for this workspace via the platform API.
Args:
workspace_id: Ignored (kept for backward compat). Checks this workspace's delegations.
task_id: Optional delegation_id to filter. If empty, returns all recent delegations.
"""
try:
async with httpx.AsyncClient(timeout=10.0) as client:
resp = await client.get(
f"{PLATFORM_URL}/workspaces/{WORKSPACE_ID}/delegations",
headers=_auth_headers_for_heartbeat(),
)
if resp.status_code != 200:
return f"Error: failed to check delegations ({resp.status_code})"
delegations = resp.json()
if task_id:
# Filter by delegation_id
matching = [d for d in delegations if d.get("delegation_id") == task_id]
if matching:
return json.dumps(matching[0])
return json.dumps({"status": "not_found", "delegation_id": task_id})
# Return all recent delegations
summary = []
for d in delegations[:10]:
summary.append({
"delegation_id": d.get("delegation_id", ""),
"target_id": d.get("target_id", ""),
"status": d.get("status", ""),
"summary": d.get("summary", ""),
"response_preview": d.get("response_preview", ""),
})
return json.dumps({"delegations": summary, "count": len(delegations)})
except Exception as e:
return f"Error checking delegations: {e}"
async def tool_send_message_to_user(message: str) -> str:
"""Send a message directly to the user's canvas chat via WebSocket."""
if not message:
return "Error: message is required"
try:
async with httpx.AsyncClient(timeout=5.0) as client:
resp = await client.post(
f"{PLATFORM_URL}/workspaces/{WORKSPACE_ID}/notify",
json={"message": message},
headers=_auth_headers_for_heartbeat(),
)
if resp.status_code == 200:
return "Message sent to user"
return f"Error: platform returned {resp.status_code}"
except Exception as e:
return f"Error sending message: {e}"
async def tool_list_peers() -> str:
"""List all workspaces this agent can communicate with."""
peers = await get_peers()
if not peers:
return "No peers available (this workspace may be isolated)"
lines = []
for p in peers:
status = p.get("status", "unknown")
role = p.get("role", "")
# Cache name for use in delegate_task
_peer_names[p["id"]] = p["name"]
lines.append(f"- {p['name']} (ID: {p['id']}, status: {status}, role: {role})")
return "\n".join(lines)
async def tool_get_workspace_info() -> str:
"""Get this workspace's own info."""
info = await get_workspace_info()
return json.dumps(info, indent=2)
async def tool_commit_memory(content: str, scope: str = "LOCAL") -> str:
"""Save important information to persistent memory.
GLOBAL scope is writable only by root workspaces (tier == 0).
RBAC memory.write permission is required for all scope levels.
The source workspace_id is embedded in every record so the platform
can enforce cross-workspace isolation and audit trail.
"""
if not content:
return "Error: content is required"
content = _redact_secrets(content)
scope = scope.upper()
if scope not in ("LOCAL", "TEAM", "GLOBAL"):
scope = "LOCAL"
# RBAC: require memory.write permission (mirrors builtin_tools/memory.py)
if not _check_memory_write_permission():
return (
"Error: RBAC — this workspace does not have the 'memory.write' "
"permission for this operation."
)
# Scope enforcement: only root workspaces (tier 0) can write GLOBAL memory.
# This prevents tenant workspaces from poisoning org-wide memory (GH#1610).
if scope == "GLOBAL" and not _is_root_workspace():
return (
"Error: RBAC — only root workspaces (tier 0) can write to GLOBAL scope. "
"Non-root workspaces may use LOCAL or TEAM scope."
)
try:
async with httpx.AsyncClient(timeout=10.0) as client:
resp = await client.post(
f"{PLATFORM_URL}/workspaces/{WORKSPACE_ID}/memories",
json={
"content": content,
"scope": scope,
# Embed source workspace so the platform can namespace-isolate
# and audit cross-workspace writes (GH#1610 fix).
"workspace_id": WORKSPACE_ID,
},
headers=_auth_headers_for_heartbeat(),
)
data = resp.json()
if resp.status_code in (200, 201):
return json.dumps({"success": True, "id": data.get("id"), "scope": scope})
return f"Error: {data.get('error', resp.text)}"
except Exception as e:
return f"Error saving memory: {e}"
async def tool_recall_memory(query: str = "", scope: str = "") -> str:
"""Search persistent memory for previously saved information.
RBAC memory.read permission is required (mirrors builtin_tools/memory.py).
The workspace_id is sent as a query parameter so the platform can
cross-validate it against the auth token and defend against any future
path traversal / cross-tenant read bugs in the platform itself.
"""
# RBAC: require memory.read permission (mirrors builtin_tools/memory.py)
if not _check_memory_read_permission():
return (
"Error: RBAC — this workspace does not have the 'memory.read' "
"permission for this operation."
)
params: dict[str, str] = {"workspace_id": WORKSPACE_ID}
if query:
params["q"] = query
if scope:
params["scope"] = scope.upper()
try:
async with httpx.AsyncClient(timeout=10.0) as client:
resp = await client.get(
f"{PLATFORM_URL}/workspaces/{WORKSPACE_ID}/memories",
params=params,
headers=_auth_headers_for_heartbeat(),
)
data = resp.json()
if isinstance(data, list):
if not data:
return "No memories found."
lines = []
for m in data:
lines.append(f"[{m.get('scope', '?')}] {m.get('content', '')}")
return "\n".join(lines)
return json.dumps(data)
except Exception as e:
return f"Error recalling memory: {e}"