Files
odysseus/src/tool_capabilities.py
T
nopozandRaresKeY f88e2d1f7f Merge commit from fork
* fix(security): stop API tokens reaching privileged agent tools

A bearer API token resolves to the human who minted it, and minting is admin-only, so every owner-keyed privilege check in the agent path answers "admin". A token issued for a narrow integration therefore reached bash and python with the authority of the account that created it.

Three independent routes to that sink, each closed here.

The token could answer its own tool-approval prompt. An approval records that a person authorized one dangerous action, and a token cannot make that statement, so /api/chat_stream now refuses an approval resume from a bearer caller.

The chat-session grant was reconstructable from caller-supplied message metadata. Two routes persist a metadata blob on the caller's behalf, so the shape of a resolved approval card could be written straight into a transcript and was then read back as authority. The server now signs the grant when it resolves an approval and verifies that signature when reading it back, binding it to the chat and the approval it was issued for. Both routes also drop server-owned keys from an inbound blob.

A run driven by a token inherited its owner's tool set. Such a run is now capped at the non-admin policy regardless of who minted the credential, which holds even where no approval is raised at all.

The human path is unchanged: a browser session still receives the prompt, still approves, and a granted chat-session scope still carries to later turns in that chat.

Scope enforcement across the wider route surface is a separate gap and is not addressed here.

* fix scoped chat delegation boundaries

* fix(auth): reject malformed chat approval signatures

---------

Co-authored-by: RaresKeY <158580472+RaresKeY@users.noreply.github.com>
2026-09-05 19:20:49 +02:00

709 lines
24 KiB
Python

"""Deterministic capability metadata for agent tools.
Model output requests an action; it never supplies the authority for that
action. This module classifies the effects of each built-in tool and applies
run-local integrity gates before dispatch.
"""
from __future__ import annotations
import json
import uuid
from dataclasses import dataclass, field
from enum import Enum
from types import MappingProxyType
from typing import Any, Iterable, Mapping
from src.tool_approval_scopes import CHAT_SESSION_APPROVAL_CONTEXT_MARKER
from src.tool_security import BUILTIN_EMAIL_TOOLS, is_public_blocked_tool
class ToolEffect(str, Enum):
READ_PUBLIC = "read_public"
READ_WORKSPACE = "read_workspace"
READ_PRIVATE = "read_private"
WRITE_WORKSPACE = "write_workspace"
WRITE_PRIVATE = "write_private"
EXECUTE_CODE = "execute_code"
BROKERED_NETWORK_READ = "brokered_network_read"
NETWORK_EGRESS = "network_egress"
EXTERNAL_SIDE_EFFECT = "external_side_effect"
UI_SIDE_EFFECT = "ui_side_effect"
ADMIN_CHANGE = "admin_change"
DESTRUCTIVE = "destructive"
USER_INTERACTION = "user_interaction"
class ResultIntegrity(str, Enum):
SYSTEM = "system"
WORKSPACE_UNTRUSTED = "workspace_untrusted"
EXTERNAL_UNTRUSTED = "external_untrusted"
@dataclass(frozen=True)
class ToolCapabilities:
effects: frozenset[ToolEffect]
result_integrity: ResultIntegrity = ResultIntegrity.SYSTEM
known: bool = True
def _capabilities(
*effects: ToolEffect,
result_integrity: ResultIntegrity = ResultIntegrity.SYSTEM,
) -> ToolCapabilities:
return ToolCapabilities(frozenset(effects), result_integrity)
_REGISTRY: dict[str, ToolCapabilities] = {}
def _register(
names: Iterable[str],
*effects: ToolEffect,
result_integrity: ResultIntegrity = ResultIntegrity.SYSTEM,
) -> None:
capabilities = _capabilities(*effects, result_integrity=result_integrity)
for name in names:
if name in _REGISTRY:
raise RuntimeError(f"Duplicate tool capability classification: {name}")
_REGISTRY[name] = capabilities
_register(
{"ask_user", "update_plan"},
ToolEffect.USER_INTERACTION,
)
_register(
{
"list_cached_models",
"list_cookbook_servers",
"list_downloads",
"list_models",
"list_serve_presets",
"list_served_models",
},
ToolEffect.READ_PRIVATE,
# These readers return provider-controlled model identifiers or durable
# user/admin-authored Cookbook and process state. Local brokering does not
# make the returned text server-authored.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"search_hf_models"},
ToolEffect.BROKERED_NETWORK_READ,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"get_workspace", "glob", "grep", "ls", "read_file"},
ToolEffect.READ_WORKSPACE,
result_integrity=ResultIntegrity.WORKSPACE_UNTRUSTED,
)
_register(
{"web_search"},
ToolEffect.BROKERED_NETWORK_READ,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"web_fetch"},
ToolEffect.BROKERED_NETWORK_READ,
ToolEffect.NETWORK_EGRESS,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{
"list_email_accounts",
"list_emails",
"read_email",
"resolve_contact",
"scan_email_unsubscribes",
"search_chats",
"search_emails",
"list_sessions",
"tail_serve_output",
"vault_get",
"vault_search",
},
ToolEffect.READ_PRIVATE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"bash", "manage_bg_jobs", "python"},
ToolEffect.EXECUTE_CODE,
result_integrity=ResultIntegrity.WORKSPACE_UNTRUSTED,
)
_register(
{"apply_patch", "edit_file", "write_file"},
ToolEffect.WRITE_WORKSPACE,
# Successful writes include unified diffs that can echo arbitrary existing
# workspace content back into the next model round.
result_integrity=ResultIntegrity.WORKSPACE_UNTRUSTED,
)
_register(
{
"create_document",
"manage_calendar",
"manage_contact",
"manage_documents",
"manage_memory",
"manage_notes",
"manage_research",
"manage_session",
"manage_skills",
"manage_tasks",
"suggest_document",
"todowrite",
},
ToolEffect.WRITE_PRIVATE,
)
_register(
{
"ai_draft_email_reply",
"create_session",
"draft_email",
"draft_email_reply",
},
ToolEffect.WRITE_PRIVATE,
# These tools resolve user-configured endpoints/accounts or read stored
# email content before returning model-visible status text.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"edit_document", "update_document"},
ToolEffect.WRITE_PRIVATE,
# These tools can echo stored document content that was not present in
# their arguments. edit_document returns the complete edited document;
# update_document also preserves stored email headers/thread history.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"pipeline"},
ToolEffect.NETWORK_EGRESS,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"send_to_session"},
ToolEffect.NETWORK_EGRESS,
ToolEffect.WRITE_PRIVATE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"chat_with_model", "ask_teacher"},
ToolEffect.NETWORK_EGRESS,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"download_attachment"},
ToolEffect.READ_PRIVATE,
ToolEffect.WRITE_WORKSPACE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"edit_image", "generate_image", "trigger_research"},
ToolEffect.NETWORK_EGRESS,
ToolEffect.WRITE_PRIVATE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{
"archive_email",
"bulk_email",
"mark_email_read",
"reply_to_email",
"send_email",
"unsubscribe_email",
},
ToolEffect.EXTERNAL_SIDE_EFFECT,
# Email action results can include stored headers/account labels or remote
# SMTP/IMAP responses, even when the action itself succeeded.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"delete_email"},
ToolEffect.EXTERNAL_SIDE_EFFECT,
ToolEffect.DESTRUCTIVE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{"ui_control"},
ToolEffect.UI_SIDE_EFFECT,
# Model switches and custom-theme validation read mutable user settings.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{
"adopt_served_model",
"cancel_download",
"download_model",
"serve_model",
"serve_preset",
"stop_served_model",
"vault_unlock",
},
ToolEffect.ADMIN_CHANGE,
# Cookbook/process operations can return stored presets, provider data,
# remote shell output, and command errors.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_register(
{
"api_call",
"app_api",
"manage_endpoints",
"manage_mcp",
"manage_settings",
"manage_tokens",
"manage_webhooks",
},
ToolEffect.ADMIN_CHANGE,
# api_call/app_api return remote or stored application data, and the
# admin managers can echo user-controlled configuration. Conservatively
# retain the action effect while treating every successful result as data.
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
TOOL_CAPABILITIES: Mapping[str, ToolCapabilities] = MappingProxyType(dict(_REGISTRY))
KNOWN_CAPABILITY_TOOLS = frozenset(TOOL_CAPABILITIES)
_UNKNOWN_CAPABILITIES = _capabilities(
ToolEffect.READ_PRIVATE,
ToolEffect.WRITE_WORKSPACE,
ToolEffect.WRITE_PRIVATE,
ToolEffect.EXECUTE_CODE,
ToolEffect.NETWORK_EGRESS,
ToolEffect.EXTERNAL_SIDE_EFFECT,
ToolEffect.ADMIN_CHANGE,
ToolEffect.DESTRUCTIVE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_UNKNOWN_CAPABILITIES = ToolCapabilities(
_UNKNOWN_CAPABILITIES.effects,
_UNKNOWN_CAPABILITIES.result_integrity,
known=False,
)
_BROWSER_MCP_READ_CAPABILITIES = _capabilities(
ToolEffect.BROKERED_NETWORK_READ,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
_BROWSER_MCP_READ_TOOLS = frozenset(
{
"mcp__builtin_browser__browser_console_messages",
"mcp__builtin_browser__browser_network_requests",
"mcp__builtin_browser__browser_snapshot",
"mcp__builtin_browser__browser_take_screenshot",
}
)
def capabilities_for_tool(tool_name: Any) -> ToolCapabilities:
"""Return deterministic capabilities; malformed and unknown tools fail high."""
if not isinstance(tool_name, str) or not tool_name:
return _UNKNOWN_CAPABILITIES
capabilities = TOOL_CAPABILITIES.get(tool_name)
if capabilities is not None:
return capabilities
if tool_name.startswith("mcp__email__"):
bare_name = tool_name[len("mcp__email__"):]
capabilities = TOOL_CAPABILITIES.get(bare_name)
if bare_name in BUILTIN_EMAIL_TOOLS and capabilities is not None:
return capabilities
if tool_name in _BROWSER_MCP_READ_TOOLS:
return _BROWSER_MCP_READ_CAPABILITIES
return _UNKNOWN_CAPABILITIES
_PRIVATE_ACTION_READS: Mapping[str, frozenset[str]] = MappingProxyType(
{
"manage_calendar": frozenset({"list_calendars", "list_events"}),
"manage_contact": frozenset({"list"}),
"manage_documents": frozenset({"list", "read", "view", "open", "get"}),
"manage_memory": frozenset({"list", "search"}),
"manage_notes": frozenset({"list", "search", "find", "view"}),
"manage_research": frozenset({"list", "read", "open", "view", "get"}),
"manage_session": frozenset({"list", "switch", "open", "select", "view"}),
"manage_skills": frozenset({"list", "index", "view", "view_ref", "search"}),
"manage_tasks": frozenset({"list"}),
}
)
_PRIVATE_ACTION_WRITES: Mapping[str, frozenset[str]] = MappingProxyType(
{
"manage_calendar": frozenset(
{"create_event", "update_event", "delete_event"}
),
"manage_contact": frozenset({"add", "update", "edit", "delete"}),
"manage_documents": frozenset({"delete", "tidy"}),
"manage_memory": frozenset({"add", "edit", "delete"}),
"manage_notes": frozenset({"add", "update", "delete", "toggle_item"}),
"manage_research": frozenset({"delete"}),
"manage_session": frozenset(
{
"rename",
"archive",
"unarchive",
"delete",
"important",
"unimportant",
"truncate",
"fork",
}
),
"manage_skills": frozenset({"add", "edit", "patch", "publish", "delete"}),
"manage_tasks": frozenset({"create", "edit", "delete", "pause", "resume", "run"}),
}
)
_ACTION_DESTRUCTIVE: Mapping[str, frozenset[str]] = MappingProxyType(
{
"manage_calendar": frozenset({"delete_event"}),
"manage_contact": frozenset({"delete"}),
"manage_documents": frozenset({"delete", "tidy"}),
"manage_endpoints": frozenset({"delete"}),
"manage_bg_jobs": frozenset({"kill", "stop", "cancel", "terminate"}),
"manage_memory": frozenset({"delete"}),
"manage_mcp": frozenset({"delete"}),
"manage_notes": frozenset({"delete"}),
"manage_research": frozenset({"delete"}),
"manage_session": frozenset({"delete", "truncate"}),
"manage_settings": frozenset({"delete", "reset"}),
"manage_skills": frozenset({"delete"}),
"manage_tasks": frozenset({"delete"}),
"manage_tokens": frozenset({"delete"}),
"manage_webhooks": frozenset({"delete"}),
}
)
_ACTION_DEFAULTS: Mapping[str, str] = MappingProxyType(
{
"manage_calendar": "list_events",
"manage_documents": "list",
"manage_research": "list",
"manage_tasks": "list",
}
)
_ACTION_ALIASES: Mapping[str, Mapping[str, str]] = MappingProxyType(
{
"manage_calendar": MappingProxyType(
{
"create": "create_event",
"update": "update_event",
"delete": "delete_event",
"list": "list_events",
}
),
"manage_notes": MappingProxyType(
{
"create": "add",
"new": "add",
"save": "add",
"remind": "add",
"reminder": "add",
"remove": "delete",
"remove_item": "toggle_item",
}
),
}
)
_LINE_ACTION_TOOLS = frozenset({"manage_memory", "manage_session"})
def _action_from_content(tool_name: str, content: Any) -> str | None:
"""Extract the action discriminator using the same accepted input shapes."""
if isinstance(content, Mapping):
payload: Any = dict(content)
elif isinstance(content, str):
raw = content.strip()
if tool_name in _LINE_ACTION_TOOLS and raw and not raw.startswith("{"):
return raw.splitlines()[0].strip().replace("-", "_").casefold() or None
try:
payload = json.loads(raw) if raw else {}
except (TypeError, ValueError):
return None
else:
payload = {}
if not isinstance(payload, dict):
return None
if (
len(payload) == 1
and isinstance(payload.get("body"), dict)
and "action" in payload["body"]
):
payload = payload["body"]
action = payload.get("action")
if (
not action
and tool_name == "manage_calendar"
and isinstance(payload.get("events"), list)
):
action = "create_event"
if not action and tool_name == "manage_tasks" and any(
payload.get(key) is not None
for key in ("task", "description", "schedule", "time", "day_of_week")
):
action = "create"
if not isinstance(action, str) or not action.strip():
action = _ACTION_DEFAULTS.get(tool_name)
if not action:
return None
normalized = action.strip().replace("-", "_").casefold()
return _ACTION_ALIASES.get(tool_name, {}).get(normalized, normalized)
def capabilities_for_action(tool_name: Any, content: Any) -> ToolCapabilities:
"""Classify a sealed multiplexed action; ambiguous actions fail high."""
base = capabilities_for_tool(tool_name)
if not isinstance(tool_name, str):
return base
action = _action_from_content(tool_name, content)
destructive = action in _ACTION_DESTRUCTIVE.get(tool_name, ())
if tool_name not in _PRIVATE_ACTION_READS:
if not destructive:
return base
return ToolCapabilities(
frozenset(set(base.effects) | {ToolEffect.DESTRUCTIVE}),
base.result_integrity,
known=base.known,
)
if action in _PRIVATE_ACTION_READS[tool_name]:
return _capabilities(
ToolEffect.READ_PRIVATE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
if action in _PRIVATE_ACTION_WRITES[tool_name]:
effects = set(base.effects)
if destructive:
effects.add(ToolEffect.DESTRUCTIVE)
return ToolCapabilities(
frozenset(effects),
ResultIntegrity.EXTERNAL_UNTRUSTED,
known=base.known,
)
return _capabilities(
ToolEffect.READ_PRIVATE,
ToolEffect.WRITE_PRIVATE,
result_integrity=ResultIntegrity.EXTERNAL_UNTRUSTED,
)
def tool_result_is_successful(result: Any) -> bool:
"""Return whether a result actually introduced successful tool output."""
return bool(
isinstance(result, dict)
and not result.get("blocked")
and not result.get("approval_required")
and not result.get("error")
and result.get("exit_code") in (None, 0)
and result.get("success") is not False
)
def tool_result_should_arm_gate(
tool_name: Any,
result: Any,
content: Any = None,
) -> bool:
"""Return whether a result introduced non-system content to the model.
A blocked/approval placeholder and a genuinely content-free failure do not
change authority. Once a non-system tool returns text or structured data
that will be folded into model context, however, failure status cannot make
that payload trusted: MCP ``isError`` text, provider exception messages,
and HTTP error bodies are all attacker-controlled input surfaces.
"""
if not isinstance(result, dict):
return False
if result.get("blocked") or result.get("approval_required"):
return False
# A producer that knows a particular response body came from a remote or
# stored source overrides a coarse static SYSTEM default.
if result.get("untrusted_content") is True:
return True
capabilities = capabilities_for_action(tool_name, content)
if capabilities.result_integrity is ResultIntegrity.SYSTEM:
return False
if tool_result_is_successful(result):
return True
# ``format_tool_result`` serializes every additional structured field, so
# a fixed allowlist here would inevitably miss model-visible payloads such
# as ``details``, ``events``, or provider-specific response keys. Exclude
# only status/policy controls that carry no producer content; any other
# non-empty field crosses the same integrity boundary even on failure.
non_content_keys = frozenset(
{
"approval_required",
"blocked",
"exit_code",
"policy",
"success",
"untrusted_content",
}
)
return any(
key not in non_content_keys and value not in (None, "", [], {}, ())
for key, value in result.items()
)
POST_EXTERNAL_BLOCKED_EFFECTS = frozenset(
{
ToolEffect.READ_PRIVATE,
ToolEffect.WRITE_WORKSPACE,
ToolEffect.WRITE_PRIVATE,
ToolEffect.EXECUTE_CODE,
ToolEffect.NETWORK_EGRESS,
ToolEffect.EXTERNAL_SIDE_EFFECT,
ToolEffect.UI_SIDE_EFFECT,
ToolEffect.ADMIN_CHANGE,
ToolEffect.DESTRUCTIVE,
}
)
@dataclass(frozen=True)
class ToolGateDecision:
allowed: bool
reason: str | None = None
_EXTERNAL_MESSAGE_SOURCES = frozenset(
{
"injected research context",
"prefetched search context",
"research context",
"web search results",
"youtube transcript",
}
)
_EXTERNAL_MESSAGE_SOURCE_PREFIXES = ("web page:",)
def messages_contain_external_untrusted_context(messages: Iterable[dict]) -> bool:
"""Detect explicitly labelled external context already present in a run."""
for message in messages or ():
if not isinstance(message, dict):
continue
metadata = message.get("metadata")
if not isinstance(metadata, dict) or metadata.get("trusted") is not False:
continue
gate_marker = metadata.get("tool_gate_untrusted")
if gate_marker is True:
return True
if gate_marker is False:
# Explicit current-format opt-outs are authoritative. The source
# label heuristics below exist only for older saved wrappers that
# predate the marker.
continue
if metadata.get("provenance_origin") == "external":
return True
source = metadata.get("source")
if not isinstance(source, str):
continue
normalized_source = source.strip().casefold()
if normalized_source in _EXTERNAL_MESSAGE_SOURCES:
return True
if normalized_source.startswith(_EXTERNAL_MESSAGE_SOURCE_PREFIXES):
return True
return False
@dataclass
class ToolRunSecurityContext:
"""Server-owned integrity state for one agent run."""
external_untrusted_context_seen: bool = False
external_sources: list[str] = field(default_factory=list)
run_id: str = field(default_factory=lambda: uuid.uuid4().hex)
# Task-scope approval sets this for the resumed in-memory run. Chat-scope
# approval is projected from the server-owned session history marker below.
# The bypass affects only this automatic gate; current tool policy, ownership,
# workspace confinement, and execution/sandbox restrictions still apply.
approval_gate_bypassed: bool = False
# Driven by a bearer API token, not a person at a browser. Privileged
# tools are refused outright and no approval can lift that.
delegated_credential: bool = False
def observe_messages(self, messages: Iterable[dict]) -> None:
"""Apply server-owned chat scope and promote untrusted prompt context."""
message_list = list(messages or ())
if self.delegated_credential:
# A delegated run has no human to grant chat-session scope, so a
# grant sitting in this chat's history (left by the owner's own
# browser) must not be picked up by a token driving the same chat.
self.approval_gate_bypassed = False
if messages_contain_external_untrusted_context(message_list):
self.external_untrusted_context_seen = True
return
if any(
isinstance(message, dict)
and isinstance(message.get("metadata"), dict)
and message["metadata"].get(
CHAT_SESSION_APPROVAL_CONTEXT_MARKER
) is True
for message in message_list
):
self.approval_gate_bypassed = True
if messages_contain_external_untrusted_context(message_list):
self.external_untrusted_context_seen = True
def decision_for(self, tool_name: Any, content: Any = None) -> ToolGateDecision:
# Checked before the bypasses below, because neither may lift it, and
# kept independent of external_untrusted_context_seen so it holds on a
# run where that gate never arms and raises no prompt to bypass.
if self.delegated_credential and is_public_blocked_tool(tool_name):
return ToolGateDecision(
False,
(
f"Tool '{tool_name}' is not available to API-token callers. "
"It requires an interactive session."
),
)
if self.approval_gate_bypassed:
return ToolGateDecision(True)
if not self.external_untrusted_context_seen:
return ToolGateDecision(True)
capabilities = capabilities_for_action(tool_name, content)
blocked_effects = capabilities.effects & POST_EXTERNAL_BLOCKED_EFFECTS
if capabilities.known and not blocked_effects:
return ToolGateDecision(True)
effects = ", ".join(sorted(effect.value for effect in blocked_effects))
if not capabilities.known:
effects = "unknown/high-impact"
return ToolGateDecision(
False,
(
"External untrusted context has already influenced this run. "
f"Tool '{tool_name}' requires a separate user-authorized action "
f"because it can cause {effects}."
),
)
def observe_tool_result(
self,
tool_name: Any,
result: Any,
content: Any = None,
) -> None:
if not tool_result_should_arm_gate(tool_name, result, content):
return
self.external_untrusted_context_seen = True
if isinstance(tool_name, str) and tool_name not in self.external_sources:
self.external_sources.append(tool_name)
def blocked_tool_result(tool_name: Any, reason: str) -> tuple[str, dict]:
return (
f"{tool_name}: BLOCKED",
{
"error": reason,
"exit_code": 1,
"blocked": True,
"policy": "external_untrusted_context",
},
)